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Sample records for cyberknife radiotherapie robotisee

  1. A noninvasive eye fixation monitoring system for CyberKnife radiotherapy of choroidal and orbital tumors

    SciTech Connect

    Daftari, I. K.; Petti, P. L.; Larson, D. A.; O'Brien, J. M.; Phillips, T. L.

    2009-03-15

    A new noninvasive monitoring system for fixing the eye has been developed to treat orbital and choroidal tumors with CyberKnife-based radiotherapy. This device monitors the eye during CT/MRI scanning and during treatment. The results of this study demonstrate the feasibility of the fixation light system for CyberKnife-based treatments of orbital and choroidal tumors and supports the idea that larger choroidal melanomas and choroidal metastases could be treated with CyberKnife without implanting fiducial markers.

  2. Dosimetric evaluation of four-dimensional dose distributions of CyberKnife and volumetric-modulated arc radiotherapy in stereotactic body lung radiotherapy.

    PubMed

    Chan, Mark K H; Kwong, Dora L W; Law, Gilbert M L; Tam, Eric; Tong, Anthony; Lee, Venus; Ng, Sherry C Y

    2013-07-08

    Advanced image-guided stereotatic body lung radiotherapy techniques using volumetric-modulated arc radiotherapy (VMAT) with four-dimensional cone-beam computed tomography (4D CBCT) and CyberKnife with real-time target tracking have been clinically implemented by different authors. However, dosimetric comparisons between these techniques are lacking. In this study, 4D CT scans of 14 patients were used to create VMAT and CyberKnife treatment plans using 4D dose calculations. The GTV and the organs at risk (OARs) were defined on the end-exhale images for CyberKnife planning and were then deformed to the midventilation images (MidV) for VMAT optimization. Direct 4D Monte Carlo dose optimizations were performed for CyberKnife (4D(CK)). Four-dimensional dose calculations were also applied to VMAT plans to generate the 4D dose distributions (4D(VMAT)) on the exhale images for direct comparisons with the 4D(CK) plans. 4D(CK) and 4D(VMAT) showed comparable target conformity (1.31 ± 0.13 vs. 1.39 ± 0.24, p = 0.05). GTV mean doses were significantly higher with 4D(CK). Statistical differences of dose volume metrics were not observed in the majority of OARs studied, except for esophagus, with 4D(VMAT) yielding marginally higher D1% than 4D(CK). The normal tissue volumes receiving 80%, 50%, and 30% of the prescription dose (V80%, V50%, and V30%) were higher with 4D(VMAT), whereas 4D(CK) yielded slightly higher V10% in posterior lesions than 4D(VMAT). VMAT resulted in much less monitor units and therefore greater delivery efficiency than CyberKnife. In general, it was possible to produce dosimetrically acceptable plans with both techniques. The selection of treatment modality should consider the dosimetric results as well as the patient's tolerance of the treatment process specific to the SBRT technique.

  3. A Retrospective Review of CyberKnife Stereotactic Body Radiotherapy for Adrenal Tumors (Primary and Metastatic): Winthrop University Hospital Experience

    PubMed Central

    Desai, Amishi; Rai, Hema; Haas, Jonathan; Witten, Matthew; Blacksburg, Seth; Schneider, Jeffrey G.

    2015-01-01

    The adrenal gland is a common site of cancer metastasis. Surgery remains a mainstay of treatment for solitary adrenal metastasis. For patients who cannot undergo surgery, radiation is an alternative option. Stereotactic body radiotherapy (SBRT) is an ablative treatment option allowing larger doses to be delivered over a shorter period of time. In this study, we report on our experience with the use of SBRT to treat adrenal metastases using CyberKnife technology. We retrospectively reviewed the Winthrop University radiation oncology data base to identify 14 patients for whom SBRT was administered to treat malignant adrenal disease. Of the factors examined, the biological equivalent dose (BED) of radiation delivered was found to be the most important predictor of local adrenal tumor control. We conclude that CyberKnife-based SBRT is a safe, non-invasive modality that has broadened the therapeutic options for the treatment of isolated adrenal metastases. PMID:26347852

  4. Direct tumor in vivo dosimetry in highly-conformal radiotherapy: A feasibility study of implantable MOSFETs for hypofractionated extracranial treatments using the Cyberknife system

    SciTech Connect

    Scalchi, Paolo; Righetto, Roberto; Cavedon, Carlo; Francescon, Paolo; Colombo, Federico

    2010-04-15

    Purpose: In highly-conformal radiotherapy, due to the complexity of both beam configurations and dose distributions, traditional in vivo dosimetry is unpractical or even impossible. The ideal dosimeter would be implanted inside the planning treatment volume so that it can directly measure the total delivered dose during each fraction with no additional uncertainty due to calculation models. The aim of this work is to verify if implantable metal oxide semiconductors field effect transistors (MOSFETs) can achieve a sufficient degree of dosimetric accuracy when used inside extracranial targets undergoing radiotherapy treatments using the Cyberknife system. Methods: Based on the preliminary findings of this study, new prototypes for high dose fractionations were developed to reduce the time dependence for long treatment delivery times. These dosimeters were recently cleared and are marketed as DVS-HFT. Multiple measurements were performed using both Virtual Water and water phantoms to characterize implantable MOSFETs under the Cyberknife beams, and included the reference-dosimetry consistency, the dependence of the response on the collimator size, on the daily delivered dose, and the time irradiation modality. Finally a Cyberknife prostate treatment simulation using a body phantom was conducted, and both MOSFET and ionization readings were compared to Monte Carlo calculations. The feasibility analysis was conducted based on the ratios of the absorbed dose divided by the dose reading, named as ''further calibration factor'' (FCF). Results: The average FCFs resulted to be 0.98 for the collimator dependence test, and about 1.00 for the reference-dosimetry test, the dose-dependence test, and the time-dependence test. The average FCF of the prostate treatment simulation test was 0.99. Conclusions: The obtained results are well within DVS specifications, that is, the factory calibration is still valid for such kind of treatments using the Cyberknife system, with no need of

  5. CyberKnife Stereotactic Ablative Radiotherapy as an Option of Treatment for Patients With Prostate Cancer Having Oligometastatic Lymph Nodes: Single-Center Study Outcome Evaluation.

    PubMed

    Napieralska, Aleksandra; Miszczyk, Leszek; Stąpór-Fudzińska, Małgorzata

    2016-10-01

    The aim of this study was to evaluate the effectiveness of CyberKnife-based stereotactic ablative radiotherapy on prostate cancer lymph node metastases. Our material consisted of 18 patients with 31 metastatic lymph nodes irradiated between 2011 and 2014 using CyberKnife-based stereotactic ablative radiotherapy. Patients were irradiated using fraction dose varied from 6 to 15 Gy (median 10), to the total dose of 24 to 45 Gy (median 30). Irradiated lymph node size varied from 0.4 to 4.0 cm. In all, 9 patients had single lymph node metastasis and 9 patients had metastases of 2 to 4 lymph nodes. Prostate-specific antigen concentration before radiotherapy varied from 0.01 to 15.58 (mean 6.97; median 4.66). All patients at the time of radiotherapy and follow-up received androgen deprivation therapy. Mann-Whitney U, Kaplan-Meier method, and log-rank tests were used in statistical analysis. We obtained the following results: after CyberKnife stereotactic ablative radiotherapy, prostate-specific antigen concentration dropped in majority of cases and during the last control varied from 0.00 to 258.00 (median 2.5), and was lower in patients without dissemination to other organs (P = .01). Complete regression was found in 12 lesions, stable disease in 13, and progression in 4. In 7 patients, the dissemination to other organs occurred. Our results allow us to conclude that CyberKnife stereotactic ablative radiotherapy of prostate cancer lymph node oligometastases gives good local control and relatively good prostate-specific antigen response.

  6. Poster — Thur Eve — 23: Dose and Position Quality Assurance using the RADPOS System for 4D Radiotherapy with CyberKnife

    SciTech Connect

    Marants, R; Vandervoort, E; Cygler, J E

    2014-08-15

    Introduction: RADPOS 4D dosimetry system consists of a microMOSFET dosimeter combined with an electromagnetic positioning sensor, which allows for performing real-time dose and position measurements simultaneously. In this report the use of RADPOS as an independent quality assurance (QA) tool during CyberKnife 4D radiotherapy treatment is described. In addition to RADPOS, GAFCHROMIC® films were used for simultaneous dose measurement. Methods: RADPOS and films were calibrated in a Solid Water® phantom at 1.5 cm depth, SAD= 80 cm, using 60 mm cone. CT based treatment plan was created for a Solid Water® breast phantom containing metal fiducials and RADPOS probe. Dose calculations were performed using iPlan pencil beam algorithm. Before the treatment delivery, GAFCHROMIC® film was inserted inside the breast phantom, next to the RADPOS probe. Then the phantom was positioned on the chest platform of the QUASAR, to which Synchrony LED optical markers were also attached. Position logging began for RADPOS and the Synchrony tracking system, the QUASAR motion was initiated and the treatment was delivered. Results: RADPOS position measurements very closely matched the LED marker positions recorded by the Synchrony camera tracking system. The RADPOS measured dose was 2.5% higher than the average film measured dose, which is within the experimental uncertainties. Treatment plan calculated dose was 4.1 and 1.6% lower than measured by RADPOS and film, respectively. This is most likely due to the inferior nature of the dose calculation algorithm. Conclusions: Our study demonstrates that RADPOS system is a useful tool for independent QA of CyberKnife treatments.

  7. Long-term results of hypofractionated stereotactic radiotherapy with CyberKnife for growth hormone-secreting pituitary adenoma: evaluation by the Cortina consensus.

    PubMed

    Iwata, Hiromitsu; Sato, Kengo; Nomura, Ryutaro; Tabei, Yusuke; Suzuki, Ichiro; Yokota, Naoki; Inoue, Mitsuhiro; Ohta, Seiji; Yamada, Shozo; Shibamoto, Yuta

    2016-06-01

    The aim of the present study was to evaluate the safety and feasibility of hypofractionated stereotactic radiotherapy (SRT) with CyberKnife for growth hormone-secreting pituitary adenoma (GH-PA). Fifty-two patients with GH-PA were treated with hypofractionated SRT between September 2001 and October 2012. Eight patients had clinically silent GH-PA and 44 were symptomatic. Only 1 patient was inoperable. The other patients had recurrent or postoperative residual tumors on MRI. All patients had received pharmacotherapy prior to SRT with a somatostatin analog, dopamine agonist, and/or GH receptor antagonist. The marginal doses were 17.4-26.8 Gy for the 3-fraction schedule and 20.0-32.0 Gy for the 5-fraction schedule. Endocrinological remission was assessed by the Cortina consensus criteria 2010 (random GH <1 ng/ml or nadir GH after an oral glucose tolerance test <0.4 ng/ml and normalization of age- and sex-adjusted insulin-like growth factor-1). The median follow-up period was 60 months (range 27-137). The 5-year overall survival, local control, and disease-free survival rates were 100, 100, and 96 %, respectively. Nine patients (5 clinically silent and 4 symptomatic patients) satisfied the Cortina criteria without receiving further pharmacotherapy, whereas the remaining 43 patients did not. No post-SRT grade 2 or higher visual disorder occurred. Symptomatic post-SRT hypopituitarism was observed in 1 patient. CyberKnife hypofractionated SRT is safe and effective when judged by imaging findings for GH-PA. However, it may be difficult to satisfy the Cortina consensus criteria in most symptomatic patients with SRT alone. Further investigations of optimal treatments are warranted. PMID:26961771

  8. Advantages of CyberKnife for inoperable stage I peripheral non-small-cell lung cancer compared to three-dimensional conformal radiotherapy

    PubMed Central

    TONG, AN-NA; YAN, PENG; YUAN, GUANG-HUI; LV, XIAO-YAN; GONG, HAI; ZHAO, HUI; WANG, YAN-MING

    2015-01-01

    This study was conducted to compare the clinical curative effect and acute radiation lung reactions between CyberKnife (CK) and three-dimensional conformal radiotherapy (3DCRT) treatment for inoperable stage I peripheral non-small-cell lung cancer (NSCLC). We retrospectively analyzed 68 patients with inoperable stage I peripheral NSCLC between 2012 and 2013 in our institution. The CK patients were treated with 42–60 Gy in three fractions, while the 3DCRT patients were treated with a total of 60 Gy, at 2 Gy per fraction. The patients were followed up and the clinical outcome was evaluated according to the Response Evaluation Criteria in Solid Tumours. We assessed the presence of acute radiation pneumonitis and pulmonary function status by thoracic scan and pulmonary function tests following CK and 3DCRT treatment. The binary univariate logistic regression analysis demonstrated that treatment method and forced expiratory volume in 1 sec/forced vital capacity (FEV1/FVC) prior to treatment (pre-FEV1/FVC) were the main factors affecting the risk of radiation pneumonitis. The analysis of these factors through multivariate logistic regression method demonstrated that treatment method for grade 1 and 2 [odds ratio (OR)= 7.866 and 11.334, respectively) and pre-FEV1/FVC for grade 1, 2 and 3 (OR = 5.062, 11.498 and 15.042, respectively) were significant factors affecting the risk of radiation pneumonitis (P<0.05). The 68 patients were divided into two subgroups using the threshold of pre-FEV1/FVC selected by the receiver operating characteristic curve. There were significant differences between the 3DCRT and CK treatment in both the pre-FEV1/FVC <68% and ≥68% subgroups for radiation pneumonitis (P=0.023 and 0.002, respectively). There was no statistically significant change in FVC, FEV1 and carbon monoxide diffusion capacity (DCLO) in the CK group, whereas there was a decrease in DCLO in the 3DCRT group. The complete remission rate was 40 vs. 34.2% at 1 year in the CK and

  9. CyberKnife radiotherapy for malignant fibrous histiocytoma of the chest wall: A case report and review of the literature

    PubMed Central

    WANG, ZHEN; WU, XIN-HU; LI, BING; KONG, QING-TAO; SHEN, ZE-TIAN; LI, JING; LIU, ZHI-BING; ZHU, XI-XU

    2014-01-01

    Malignant fibrous histiocytoma (MFH) is the most common type of soft tissue sarcoma, but rarely originates in the chest wall. Surgical resection is considered to be the most reliable treatment, however, no consensus has been reached concerning the best treatment for unresectable MFH. The current study presents the case of a 77-year-old male with MFH of the chest wall. The patient developed a painless mass and intermittent fever over a four-month period. A computed tomography scan demonstrated a large inhomogeneous lesion in the right chest wall, which was subsequently diagnosed via biopsy as a MFH. Since the tumor was an unresectable mass, CyberKnife® radiotherapy was conducted. Following the treatment, a marked reduction in the tumor size was observed with a tolerable level of toxicity. The sequencing analysis also revealed an in-frame deletion (delE746-A750) in exon 19 of the epidermal growth factor receptor gene. Based on this result, gefitinib was administered to the patient at a dose of 250 mg/day. PMID:24932251

  10. Combination effects of tissue heterogeneity and geometric targeting error in stereotactic body radiotherapy for lung cancer using CyberKnife.

    PubMed

    Kang, Ki Mun; Jeong, Bae Kwon; Choi, Hoon-Sik; Yoo, Seung Hoon; Hwang, Ui-Jung; Lim, Young Kyung; Jeong, Hojin

    2015-09-08

    We have investigated the combined effect of tissue heterogeneity and its variation associated with geometric error in stereotactic body radiotherapy (SBRT) for lung cancer. The treatment plans for eight lung cancer patients were calculated using effective path length (EPL) correction and Monte Carlo (MC) algorithms, with both having the same beam configuration for each patient. These two kinds of plans for individual patients were then subsequently recalculated with adding systematic and random geometric errors. In the ordinary treatment plans calculated with no geometric offset, the EPL calculations, compared with the MC calculations, largely overestimated the doses to PTV by ~ 21%, whereas the overestimation were markedly lower in GTV by ~ 12% due to relatively higher density of GTV than of PTV. When recalculating the plans for individual patients with assigning the systematic and random geometric errors, no significant changes in the relative dose distribution, except for overall shift, were observed in the EPL calculations, whereas largely altered in the MC calculations with a consistent increase in dose to GTV. Considering the better accuracy of MC than EPL algorithms, the present results demonstrated the strong coupling of tissue heterogeneity and geometric error, thereby emphasizing the essential need for simultaneous correction for tissue heterogeneity and geometric targeting error in SBRT of lung cancer.

  11. Evaluation of the influence of tumor location and size on the difference of dose calculation between Ray Tracing algorithm and Fast Monte Carlo algorithm in stereotactic body radiotherapy of non-small cell lung cancer using CyberKnife.

    PubMed

    Wu, Vincent W C; Tam, Kwok-wah; Tong, Shun-ming

    2013-09-06

    This study evaluated the extent of improvement in dose predication accuracy achieved by the Fast Monte Carlo algorithm (MC) compared to the Ray Tracing algorithm (RAT) in stereotactic body radiotherapy (SBRT) of non-small cell lung cancer (NSCLC), and how their differences were influenced by the tumor site and size. Thirty-three NSCLC patients treated with SBRT by CyberKnife in 2011 were recruited. They were divided into the central target group (n = 17) and peripheral target group (n = 16) according to the RTOG 0236 guidelines. Each group was further divided into the large and small target subgroups. After the computation of treatment plans using RAT, a MC plan was generated using the same patient data and treatment parameters. Apart from the target reference point dose measurements, various dose parameters for the planning target volume (PTV) and organs at risk (OARs) were assessed. In addition, the "Fractional Deviation" (FDev) was also calculated for comparison, which was defined as the ratio of the RAT and MC values. For peripheral lung cases, RAT produced significantly higher dose values in all the reference points than MC. The FDev of all reference point doses and dose parameters was greater in the small target than the large target subgroup. For central lung cases, there was no significant reference point and OAR dose differences between RAT and MC. When comparing between the small target and large target subgroups, the FDev values of all the dose parameters and reference point doses did not show significant difference. Despite the shorter computation time, RAT was inferior to MC, in which the target dose was usually overestimated. RAT would not be recommended for SBRT of peripheral lung tumors regardless of the target size. However, it could be considered for large central lung tumors because its performance was comparable to MC.

  12. Stereotactic radiosurgery - CyberKnife

    MedlinePlus

    ... slides into a machine that delivers radiation. A robotic arm controlled by a computer moves around you. ... Accuray Incorporated. CyberKnife robotic radiosurgery system patient brochure. 2012. ... Accessed ...

  13. CyberKnife radiosurgery for spinal neoplasms.

    PubMed

    Gerszten, Peter C; Burton, Steven A; Ozhasoglu, Cihat

    2007-01-01

    The role of stereotactic radiosurgery for the treatment of intracranial lesions is well established. Its use for the treatment of spinal lesions has been limited by the availability of effective target immobilization and localization technologies. Conventional external beam radiotherapy lacks the precision to allow delivery of large doses of radiation near radiosensitive structures such as the spinal cord. The CyberKnife (Accuray Inc., Sunnyvale, Calif., USA) is an imageguided frameless stereotactic radiosurgery system that allows for the radiosurgical treatment of spinal lesions. The system utilizes the coupling of an orthogonal pair of X-ray cameras to a dynamically manipulated robot-mounted lightweight linear accelerator which has 6 d.f. that guides the therapy beam to the intended target without the use of frame-based fixation. Realtime imaging tracking allows for patient movement tracking with 1mm spatial accuracy. Cervical spine lesions are located and tracked relative to skull bony landmarks; lower spinal lesions are tracked relative to percutaneously placed gold fiducial bone markers. Spinal stereotactic radiosurgery using a frameless image-guided system is now both feasible and safe. The major potential benefits of radiosurgical ablation of spinal lesions are short treatment time in an outpatient setting with rapid recovery and good symptomatic response. This technique offers a successful therapeutic modality for the treatment of a variety of spinal lesions as a primary treatment or for lesions not amenable to open surgical techniques, in medically inoperable patients, lesions located in previously irradiated sites, or as an adjunct to surgery.

  14. Synchrony - Cyberknife Respiratory Compensation Technology

    SciTech Connect

    Ozhasoglu, Cihat Saw, Cheng B.; Chen Hungcheng; Burton, Steven; Komanduri, Krishna; Yue, Ning J.; Huq, Saiful M.; Heron, Dwight E.

    2008-07-01

    Studies of organs in the thorax and abdomen have shown that these organs can move as much as 40 mm due to respiratory motion. Without compensation for this motion during the course of external beam radiation therapy, the dose coverage to target may be compromised. On the other hand, if compensation of this motion is by expansion of the margin around the target, a significant volume of normal tissue may be unnecessarily irradiated. In hypofractionated regimens, the issue of respiratory compensation becomes an important factor and is critical in single-fraction extracranial radiosurgery applications. CyberKnife is an image-guided radiosurgery system that consists of a 6-MV LINAC mounted to a robotic arm coupled through a control loop to a digital diagnostic x-ray imaging system. The robotic arm can point the beam anywhere in space with 6 degrees of freedom, without being constrained to a conventional isocenter. The CyberKnife has been recently upgraded with a real-time respiratory tracking and compensation system called Synchrony. Using external markers in conjunction with diagnostic x-ray images, Synchrony helps guide the robotic arm to move the radiation beam in real time such that the beam always remains aligned with the target. With the aid of Synchrony, the tumor motion can be tracked in three-dimensional space, and the motion-induced dosimetric change to target can be minimized with a limited margin. The working principles, advantages, limitations, and our clinical experience with this new technology will be discussed.

  15. Peripheral doses in CyberKnife radiosurgery

    SciTech Connect

    Petti, Paula L.; Chuang, Cynthia F.; Smith, Vernon; Larson, David A.

    2006-06-15

    The purpose of this work is to measure the dose outside the treatment field for conformal CyberKnife treatments, to compare the results to those obtained for similar treatments delivered with gamma knife or intensity-modulated radiation therapy (IMRT), and to investigate the sources of peripheral dose in CyberKnife radiosurgery. CyberKnife treatment plans were developed for two hypothetical lesions in an anthropomorphic phantom, one in the thorax and another in the brain, and measurements were made with LiF thermoluminescent dosimeters (TLD-100 capsules) placed within the phantom at various depths and distances from the irradiated volume. For the brain lesion, gamma knife and 6-MV IMRT treatment plans were also developed, and peripheral doses were measured at the same locations as for the CyberKnife plan. The relative contribution to the CyberKnife peripheral dose from inferior- or superior-oblique beams entering or exiting through the body, internally scattered radiation, and leakage radiation was assessed through additional experiments using the single-isocenter option of the CyberKnife treatment-planning program with different size collimators. CyberKnife peripheral doses (in cGy) ranged from 0.16 to 0.041 % ({+-}0.003%) of the delivered number of monitor units (MU) at distances between 18 and 71 cm from the field edge. These values are two to five times larger than those measured for the comparable gamma knife brain treatment, and up to a factor of four times larger those measured in the IMRT experiment. Our results indicate that the CyberKnife peripheral dose is due largely to leakage radiation, however at distances less than 40 cm from the field edge, entrance, or exit dose from inferior- or superior-oblique beams can also contribute significantly. For distances larger than 40 cm from the field edge, the CyberKnife peripheral dose is directly related to the number of MU delivered, since leakage radiation is the dominant component.

  16. Trigeminal neuralgia treatment dosimetry of the Cyberknife

    SciTech Connect

    Ho, Anthony; Lo, Anthony T.; Dieterich, Sonja; Soltys, Scott G.; Gibbs, Iris C.; Chang, Steve G.; Adler, John R.

    2012-04-01

    There are 2 Cyberknife units at Stanford University. The robot of 1 Cyberknife is positioned on the patient's right, whereas the second is on the patient's left. The present study examines whether there is any difference in dosimetry when we are treating patients with trigeminal neuralgia when the target is on the right side or the left side of the patient. In addition, we also study whether Monte Carlo dose calculation has any effect on the dosimetry. We concluded that the clinical and dosimetric outcomes of CyberKnife treatment for trigeminal neuralgia are independent of the robot position. Monte Carlo calculation algorithm may be useful in deriving the dose necessary for trigeminal neuralgia treatments.

  17. Stereotactic radiosurgery of prostate cancer - dose distribution for VMAT and CyberKnife techniques

    NASA Astrophysics Data System (ADS)

    Ślosarek, Krzysztof; Osewski, Wojciech; Grządziel, Aleksandra; Stąpór-Fudzińska, Małgorzata; Szlag, Marta

    2016-06-01

    New capabilities of biomedical accelerators allow for very precise depositing of the radiation dose and imaging verification during the therapy. In addition, computer algorithms calculating dose distributions are taking into account the increasing number of physical effects. Therefore, administration of high dose fractionation, which is consistent with radiobiology used in oncology, becomes safer and safer. Stereotactic radiosurgery (SRS), which is very precise irradiation with high dose fractionation is increasingly widespread use in radiotherapy of prostate cancer. For this purpose different biomedical accelerators are used. The aim of this study is to compare dose distributions for two techniques: VMAT and CyberKnife. Statistical analysis was performed for the two groups of patients treated by VMAT technique (25 patients), and CyberKnife technique (15 patients). The analysis shows that the dose distributions are comparable, both in the treated area (prostate) and in the critical organs (rectum, urinary bladder, femoral heads). The results show that stereotactic radiosurgery of prostate cancer can be carried out on CyberKnife accelerator as well as on the classical accelerator with the use of VMAT technique.

  18. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    SciTech Connect

    Kim, Haksoo; Welford, Scott; Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W.; Sloan, Andrew

    2014-02-15

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A

  19. Implementation of Monte Carlo Dose calculation for CyberKnife treatment planning

    NASA Astrophysics Data System (ADS)

    Ma, C.-M.; Li, J. S.; Deng, J.; Fan, J.

    2008-02-01

    Accurate dose calculation is essential to advanced stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) especially for treatment planning involving heterogeneous patient anatomy. This paper describes the implementation of a fast Monte Carlo dose calculation algorithm in SRS/SRT treatment planning for the CyberKnife® SRS/SRT system. A superposition Monte Carlo algorithm is developed for this application. Photon mean free paths and interaction types for different materials and energies as well as the tracks of secondary electrons are pre-simulated using the MCSIM system. Photon interaction forcing and splitting are applied to the source photons in the patient calculation and the pre-simulated electron tracks are repeated with proper corrections based on the tissue density and electron stopping powers. Electron energy is deposited along the tracks and accumulated in the simulation geometry. Scattered and bremsstrahlung photons are transported, after applying the Russian roulette technique, in the same way as the primary photons. Dose calculations are compared with full Monte Carlo simulations performed using EGS4/MCSIM and the CyberKnife treatment planning system (TPS) for lung, head & neck and liver treatments. Comparisons with full Monte Carlo simulations show excellent agreement (within 0.5%). More than 10% differences in the target dose are found between Monte Carlo simulations and the CyberKnife TPS for SRS/SRT lung treatment while negligible differences are shown in head and neck and liver for the cases investigated. The calculation time using our superposition Monte Carlo algorithm is reduced up to 62 times (46 times on average for 10 typical clinical cases) compared to full Monte Carlo simulations. SRS/SRT dose distributions calculated by simple dose algorithms may be significantly overestimated for small lung target volumes, which can be improved by accurate Monte Carlo dose calculations.

  20. CyberKnife Radiosurgery – Value as an Adjunct to Surgical Treatment of HCC?

    PubMed Central

    Schoenberg, Markus; Khandoga, Andrey; Stintzing, Sebastian; Trumm, Christoph; Schiergens, Tobias Simon; Angele, Martin; op den Winkel, Mark; Werner, Jens; Rentsch, Markus

    2016-01-01

    Introduction CyberKnife radiosurgery (CK) is an effective tool for the treatment of malignancies. Its greatest potential is in high-dose radiosurgery delivered to targets in organs that move with respiration, e.g., liver tumors. For hepatocellular carcinoma (HCC), however, surgical treatment (resection, transplantation) is most likely to produce long-term survival; for non-resectable tumors, therapies other than radiosurgery are typically recommended. This study evaluated the long-lasting anti-tumor effects of CK combined with surgery in patients with HCC. Materials and methods  Eighteen patients (three women, 15 men) were included in this prospective observational study. They received 21 single-fraction CK treatments (26 Gy). Patient characteristics, treatment effects, tumor response (according to the Response Evaluation Criteria In Solid Tumors (RECIST) grading) and survival were measured for a median period of 29 months. Results Local tumor control was achieved in 15 patients, with complete and partial remission observed in 10 and five patients, respectively. One patient was treated for two separate lesions in one session, and one received three treatments each separated by two-year intervals; both patients are tumor-free. Two patients showed minimal response, and in one patient local tumor viability could not be excluded by MRI. Nine patients had HCC recurrence, all distant to the treated site. Nine patients died during follow-up, including two with clear relation to tumor progress. Tumor-free survival was 79.4% after one year and 29.8% after three years, and the corresponding overall survival was 84.8% and 66%. Conclusion  This study shows the high effectiveness of single-session frameless CyberKnife radiosurgery for treatment of hepatocellular carcinoma and reconfirms previous results of fractioned radiotherapy of HCC. It also demonstrates the potential of radiosurgery to be combined with surgical concepts. PMID:27284498

  1. Quantitative measurement of CyberKnife robotic arm steering.

    PubMed

    Wong, K H; Dieterich, S; Tang, J; Cleary, K

    2007-12-01

    Respiratory motion is a significant and challenging problem for radiation medicine. Without adequate compensation for respiratory motion, it is impossible to deliver highly conformal doses to tumors in the thorax and abdomen. The CyberKnife frameless stereotactic radiosurgery system with Synchrony provides respiratory motion adaptation by monitoring skin motion and dynamically steering the beam to follow the moving tumor. This study quantitatively evaluated this beam steering technology using optical tracking of both the linear accelerator and a ball-cube target. Respiratory motion of the target was simulated using a robotic motion platform and movement patterns recorded from previous CyberKnife patients. Our results show that Synchrony respiratory tracking can achieve sub-millimeter precision when following a moving object. PMID:17994788

  2. Dosimetric Comparison Between 3-Dimensional Conformal and Robotic SBRT Treatment Plans for Accelerated Partial Breast Radiotherapy.

    PubMed

    Goggin, L M; Descovich, M; McGuinness, C; Shiao, S; Pouliot, J; Park, C

    2016-06-01

    Accelerated partial breast irradiation is an attractive alternative to conventional whole breast radiotherapy for selected patients. Recently, CyberKnife has emerged as a possible alternative to conventional techniques for accelerated partial breast irradiation. In this retrospective study, we present a dosimetric comparison between 3-dimensional conformal radiotherapy plans and CyberKnife plans using circular (Iris) and multi-leaf collimators. Nine patients who had undergone breast-conserving surgery followed by whole breast radiation were included in this retrospective study. The CyberKnife planning target volume (PTV) was defined as the lumpectomy cavity + 10 mm + 2 mm with prescription dose of 30 Gy in 5 fractions. Two sets of 3-dimensional conformal radiotherapy plans were created, one used the same definitions as described for CyberKnife and the second used the RTOG-0413 definition of the PTV: lumpectomy cavity + 15 mm + 10 mm with prescription dose of 38.5 Gy in 10 fractions. Using both PTV definitions allowed us to compare the dose delivery capabilities of each technology and to evaluate the advantage of CyberKnife tracking. For the dosimetric comparison using the same PTV margins, CyberKnife and 3-dimensional plans resulted in similar tumor coverage and dose to critical structures, with the exception of the lung V5%, which was significantly smaller for 3-dimensional conformal radiotherapy, 6.2% when compared to 39.4% for CyberKnife-Iris and 17.9% for CyberKnife-multi-leaf collimator. When the inability of 3-dimensional conformal radiotherapy to track motion is considered, the result increased to 25.6%. Both CyberKnife-Iris and CyberKnife-multi-leaf collimator plans demonstrated significantly lower average ipsilateral breast V50% (25.5% and 24.2%, respectively) than 3-dimensional conformal radiotherapy (56.2%). The CyberKnife plans were more conformal but less homogeneous than the 3-dimensional conformal radiotherapy plans. Approximately 50% shorter

  3. Performance of a Motion Tracking System During Cyberknife Robotic Radiosurgery

    SciTech Connect

    Cavedon, Carlo; Francescon, Paolo; Cora, Stefania; Moschini, Giuliano; Rossi, Paolo

    2009-03-10

    Cyberknife (Accuracy Inc., Ca) is a robotic radio-surgery system that includes a compact 6 MV linac delivering up to 800 cGy per minute, and an automate arm to aim at any part of the body from any angle. An essential tool is the guidance system based on x-ray imaging cameras located on supports around the patient. A Cyberknife system has been operational at the Vicenza (Italy) Hospital for years and is mainly employed for treating benign and malignant tumors, and Arterior-Venous Malformations. In radiation therapy, delivery of high doses to targets that move with respiration is challenging because of possible spatial inaccuracies. The purpose of this work was to estimate the accuracy of the prediction algorithm used to compensate for system latency in a real-time respiratory tracking system. We have analyzed respiratory signals of 30 patients who had lung or liver Cyberknife treatments. The 'Synchrony'(Accuracy Inc.) motion tracking system we use is based on the correlation between the position of LED markers, detected in real time, and the position of internal markers, sampled through x-ray imaging. The position of the external LED signals, though read in real time, must be predicted to compensate for a few hundred ms time lag in the feedback loop that redirects the beam to the current target position. The respiratory signals were described by employing their frequency power spectrum, as recently proposed by other authors. Prediction errors above 1.5 mm, lasting for periods longer than 5 seconds were observed for irregular breathers. These episodes correlate to the presence of a bimodal distribution in the power spectral density, and of very low frequencies contribution. A more refined approach would include a personalized choice of the prediction algorithm based on the very first minutes of treatment. Patient training aimed at reducing breathing irregularities might also result in improved spatial accuracy.

  4. Cyberknife treatment for advanced or terminal stage hepatocellular carcinoma

    PubMed Central

    Kato, Hiroyuki; Yoshida, Hideo; Taniguch, Hiroyoshi; Nomura, Ryutaro; Sato, Kengo; Suzuki, Ichiro; Nakata, Ryo

    2015-01-01

    AIM: To investigate the safety and efficacy of the Cyberknife treatment for patients with advanced or terminal stage hepatocellular carcinoma (HCC). METHODS: Patients with HCC with extrahepatic metastasis or vascular or bile duct invasion were enrolled between May 2011 and June 2015. The Cyberknife was used to treat each lesion. Treatment response scores were based on Response Evaluation Criteria in Solid Tumors v1.1. The trends of tumor markers, including alpha fetoprotein (AFP) and proteins induced by vitamin K absence II (PIVKA II) were assessed. Prognostic factors for tumor response and tumor markers were evaluated with Fisher’s exact test and a logistic regression model. Survival was evaluated with the Kaplan-Meier method and multivariate analysis was performed using the Cox proportional hazards model. RESULTS: Sixty-five patients with 95 lesions were enrolled. Based on the Barcelona Clinic Liver Cancer classification, all patients were either in the advanced or terminal stage of the disease. The target lesions were as follows: 52 were bone metastasis; 9, lung metastasis; 7, brain metastasis; 9, portal vein invasion; 4, hepatic vein invasion; 4, bile duct invasion; and 10 other lesion types. The response rate and disease control rate were 34% and 53%, respectively. None of the clinical factors correlated significantly with tumor response. Fiducial marker implantation was associated with better control of both AFP (HR = 0.152; 95%CI: 0.026-0.887; P = 0.036) and PIVKA II (HR = 0.035; 95%CI: 0.003-0.342; P = 0.004). The median survival time was 9 mo (95%CI: 5-15 mo). Terminal stage disease (HR = 9.809; 95%CI: 2.589-37.17, P < 0.001) and an AFP of more than 400 ng/mL (HR = 2.548; 95%CI: 1.070-6.068, P = 0.035) were associated with worse survival. A radiation dose higher than 30 Gy (HR = 0.274; 95%CI: 0.093-0.7541, P = 0.012) was associated with better survival. In the 52 cases of bone metastasis, 36 patients (69%) achieved pain relief. One patient had cerebral

  5. Temporal compartmental dosing effects for robotic prostate stereotactic body radiotherapy

    NASA Astrophysics Data System (ADS)

    Shiao, Stephen L.; Sahgal, Arjun; Hu, Weigang; Jabbari, Siavash; Chuang, Cynthia; Descovich, Martina; Hsu, I.-Chow; Gottschalk, Alexander R.; Roach, Mack, III; Ma, Lijun

    2011-12-01

    The rate of dose accumulation within a given area of a target volume tends to vary significantly for non-isocentric delivery systems such as Cyberknife stereotactic body radiotherapy. In this study, we investigated whether intra-target temporal dose distributions produce significant variations in the biological equivalent dose. For the study, time courses of ten patients were reconstructed and calculation of a biologically equivalent uniform dose (EUD) was performed using a formula derived from the linear quadratic model (α/β = 3 for prostate cancer cells). The calculated EUD values obtained for the actual patient treatments were then compared with theoretical EUD values for delivering the same physical dose distribution except that the whole target being irradiated continuously (e.g. large-field ‘dose-bathing’ type of delivery). For all the case, the EUDs for the actual treatment delivery were found to correlate strongly with the EUDs for the large-field delivery: a linear correlation coefficient of R2 = 0.98 was obtained and the average EUD for the actual Cyberknife delivery was somewhat higher (5.0 ± 4.7%) than that for the large-field delivery. However, no statistical significance was detected between the two types of delivery (p = 0.21). We concluded that non-isocentric small-field Cyberknife delivery produced consistent biological dosing that tracked well with the constant-dose-rate, large-field-type delivery for prostate stereotactic body radiotherapy.

  6. Cyberknife radiosurgery for squamous cell carcinoma of vulva after prior pelvic radiation therapy.

    PubMed

    Kunos, Charles; von Gruenigen, Vivian; Waggoner, Steven; Brindle, James; Zhang, Yuxia; Myers, Brenda; Funkhouser, Gary; Wessels, Barry; Einstein, Douglas

    2008-10-01

    Limited options exist for patients experiencing a local recurrence of vulvar malignancies after surgery and pelvic radiation. These recurrences often are associated with cancer-related skin desquamation and poor clinical outcomes. A new radiotherapeutic treatment modality for the previously irradiated patient is cyberknife radiosurgery, which uses a linear accelerator mounted on an industrial robotic arm to allow non-coplanar radiation therapy delivery with sub-millimeter precision. This study describes the first reported use of cyberknife radiosurgery for the treatment of recurrent vulvar cancer in three women.

  7. Dosimetric effect of CT contrast agent in CyberKnife treatment plans

    PubMed Central

    2013-01-01

    Background To investigate the effect of computed tomography (CT) contrast enhancement (CE) on the 3D dose distributions of non-coplanar small field beams in the CyberKnife (CK) treatment planning system (TPS) for the stereotactic ablative radiotherapy (SABR). Methods Twenty-two pre-CE CT treatment plans were recruited to this retrospective plan study. Their post-CE CT plans were based on the pre-CE CT plan data and calculated using the same MU and beam paths in either Ray-Tracing or Monte Carlo (MC) algorithms. The differences in the doses of the beam path and the reference point between the pre- and post-CE CT plans were compared. The minimum, maximum, and mean doses in dose-volume histograms (DVHs) of target and organs-at-risk (OARs) were also compared. Results The dose differences between the pre- and post-CE plans in a single beam path were less than 1.05% in both calculation algorithms, with respect to the prescription dose. At the center of the target volume, it was 1.9% (maximum 6.2%) in Ray-Tracing and 1.6% (maximum 4.0%) in MC. The CA effect showed on average 1.2% difference in the OAR maximum dose (maximum 7.8% in Ray-Tracing and 7.2% in MC). In the lung cases, the CT CE resulted in a dose difference of 2.4% (from 1.0% to 6.5%) without the calculation algorithm effect (maximum 20.3%). Conclusions The CK treatment plan using the post-CE CT generally afforded less than 2% dose differences from the pre-CE CT plan. However, it could be up to 7.8% depending on the target positions in a body and be more than 20% with the calculation algorithms. Thus, the post-CE CT in CK treatment plans should be used with careful consideration for the CA effect, target position, and calculation algorithm factors. PMID:24139405

  8. Extracranial Facial Nerve Schwannoma Treated by Hypo-fractionated CyberKnife Radiosurgery

    PubMed Central

    Miyazaki, Shinichiro; Hori, Tomokatsu

    2016-01-01

    Facial nerve schwannoma is a rare intracranial tumor. Treatment for this benign tumor has been controversial. Here, we report a case of extracranial facial nerve schwannoma treated successfully by hypo-fractionated CyberKnife (Accuray, Sunnyvale, CA) radiosurgery and discuss the efficacy of this treatment. A 34-year-old female noticed a swelling in her right mastoid process. The lesion enlarged over a seven-month period, and she experienced facial spasm on the right side. She was diagnosed with a facial schwannoma via a magnetic resonance imaging (MRI) scan of the head and neck and was told to wait until the facial nerve palsy subsides. She was referred to our hospital for radiation therapy. We planned a fractionated CyberKnife radiosurgery for three consecutive days. After CyberKnife radiosurgery, the mass in the right parotid gradually decreased in size, and the facial nerve palsy disappeared. At her eight-month follow-up, her facial spasm had completely disappeared. There has been no recurrence and the facial nerve function has been normal. We successfully demonstrated the efficacy of CyberKnife radiosurgery as an alternative treatment that also preserves neurofunction for facial nerve schwannomas. PMID:27774363

  9. A study on rectal dose measurement in phantom and in vivo using Gafchromic EBT3 film in IMRT and CyberKnife treatments of carcinoma of prostate

    PubMed Central

    Ganapathy, K.; Kurup, P. G. G.; Murali, V.; Muthukumaran, M.; Subramanian, S. Balaji; Velmurugan, J.

    2013-01-01

    The objective of this study is to check the feasibility of in vivo rectal dose measurement in intensity-modulated radiotherapy (IMRT) and CyberKnife treatments for carcinoma prostate. An in-house pelvis phantom made with bee's wax was used in this study. Two cylindrical bone equivalent materials were used to simulate the femur. Target and other critical structures associated with carcinoma prostate were delineated on the treatment planning images by the radiation oncologist. IMRT treatment plan was generated in Oncentra Master Plan treatment planning system and CyberKnife treatment plan was generated in Multiplan treatment planning system. Dose measurements were carried out in phantom and in patient using Gafchromic EBT3 films. RIT software was used to analyze the dose measured by EBT3 films. The measured doses using EBT3 films were compared with the TPS-calculated dose along the anterior rectal wall at multiple points. From the in-phantom measurements, it is observed that the difference between calculated and measured dose was mostly within 5%, except for a few measurement points. The difference between calculated and measured dose in the in-patient measurements was higher than 5% in regions which were away from the target. Gafchromic EBT3 film is a suitable detector for in vivo rectal dose measurements as it offers the possibility of analyzing the dose at multiple points. In addition, the method of extending this in vivo rectal dose measurement technique as a tool for patient-specific quality assurance check is also analyzed. PMID:24049320

  10. Intrafractional Motion of the Prostate During Hypofractionated Radiotherapy

    SciTech Connect

    Xie Yaoqin; Djajaputra, David; King, Christopher R.; Hossain, Sabbir; Ma Lijun; Xing Lei

    2008-09-01

    Purpose: To report the characteristics of prostate motion as tracked by the stereoscopic X-ray images of the implanted fiducials during hypofractionated radiotherapy with CyberKnife. Methods and Materials: Twenty-one patients with prostate cancer who were treated with CyberKnife between January 2005 and September 2007 were selected for this retrospective study. The CyberKnife uses a stereoscopic X-ray system to obtain the position of the prostate target through the monitoring of implanted gold fiducial markers. If there is a significant deviation, the treatment is paused while the patient is repositioned by moving the couch. The deviations calculated from X-ray images acquired within the time interval between two consecutive couch motions constitute a data set. Results: Included in the analysis were 427 data sets and 4,439 time stamps of X-ray images. The mean duration for each data set was 697 sec. At 30 sec, a motion >2 mm exists in about 5% of data sets. The percentage is increased to 8%, 11%, and 14% at 60 sec, 90 sec, and 120 sec, respectively. A similar trend exists for other values of prostate motion. Conclusions: With proper monitoring and intervention during treatment, the prostate shifts observed among patients can be kept within the tracking range of the CyberKnife. On average, a sampling rate of {approx}40 sec between consecutive X-rays is acceptable to ensure submillimeter tracking. However, there is significant movement variation among patients, and a higher sampling rate may be necessary in some patients.

  11. Retrospective evaluation of CTV to PTV margins using CyberKnife in patients with thoracic tumors.

    PubMed

    Floriano, Alejandro; García, Rafael; Moreno, Ramon; Sánchez-Reyes, Alberto

    2014-11-08

    The objectives of this study were to estimate global uncertainty for patients with thoracic tumors treated in our center using the CyberKnife VSI after placement of fiducial markers and to compare our findings with the standard CTV to PTV margins used to date. Datasets for 16 patients (54 fractions) treated with the CyberKnife and the Synchrony Respiratory Tracking System were analyzed retrospectively based on CT planning, tracking information, and movement data generated and saved in the logs files by the system. For each patient, we analyzed all the main uncertainty sources and assigned a value. We also calculated an expanded global uncertainty to ensure a robust estimation of global uncertainty and to enable us to determine the position of 95% of the CTV points with a 95% confidence level during treatment. Based on our estimation of global uncertainty and compared with our general mar- gin criterion (5 mm in all three directions: superior/inferior [SI], anterior/posterior [AP], and lateral [LAT]), 100% were adequately covered in the LAT direction, as were 94% and 94% in the SI and AP directions. We retrospectively analyzed the main sources of uncertainty in the CyberKnife process patient by patient. This individualized approach enabled us to estimate margins for patients with thoracic tumors treated in our unit and compare the results with our standard 5 mm margin. 

  12. Retrospective evaluation of CTV to PTV margins using CyberKnife in patients with thoracic tumors.

    PubMed

    Floriano, Alejandro; García, Rafael; Moreno, Ramon; Sánchez-Reyes, Alberto

    2014-01-01

    The objectives of this study were to estimate global uncertainty for patients with thoracic tumors treated in our center using the CyberKnife VSI after placement of fiducial markers and to compare our findings with the standard CTV to PTV margins used to date. Datasets for 16 patients (54 fractions) treated with the CyberKnife and the Synchrony Respiratory Tracking System were analyzed retrospectively based on CT planning, tracking information, and movement data generated and saved in the logs files by the system. For each patient, we analyzed all the main uncertainty sources and assigned a value. We also calculated an expanded global uncertainty to ensure a robust estimation of global uncertainty and to enable us to determine the position of 95% of the CTV points with a 95% confidence level during treatment. Based on our estimation of global uncertainty and compared with our general mar- gin criterion (5 mm in all three directions: superior/inferior [SI], anterior/posterior [AP], and lateral [LAT]), 100% were adequately covered in the LAT direction, as were 94% and 94% in the SI and AP directions. We retrospectively analyzed the main sources of uncertainty in the CyberKnife process patient by patient. This individualized approach enabled us to estimate margins for patients with thoracic tumors treated in our unit and compare the results with our standard 5 mm margin.  PMID:25493508

  13. Dosimetry analyses comparing high-dose-rate brachytherapy, administered as monotherapy for localized prostate cancer, with stereotactic body radiation therapy simulated using CyberKnife

    PubMed Central

    Fukuda, Shoichi; Seo, Yuji; Shiomi, Hiroya; Yamada, Yuji; Ogata, Toshiyuki; Morimoto, Masahiro; Konishi, Koji; Yoshioka, Yasuo; Ogawa, Kazuhiko

    2014-01-01

    The purpose of this study was to perform dosimetry analyses comparing high-dose-rate brachytherapy (HDR-BT) with simulated stereotactic body radiotherapy (SBRT). We selected six consecutive patients treated with HDR-BT monotherapy in 2010, and a CyberKnife SBRT plan was simulated for each patient using computed tomography images and the contouring set used in the HDR-BT plan for the actual treatment, but adding appropriate planning target volume (PTV) margins for SBRT. Then, dosimetric profiles for PTVs of the rectum, bladder and urethra were compared between the two modalities. The SBRT plan was more homogenous and provided lower dose concentration but better coverage for the PTV. The maximum doses in the rectum were higher in the HDR-BT plans. However, the HDR-BT plan provided a sharper dose fall-off around the PTV, resulting in a significant and considerable difference in volume sparing of the rectum with the appropriate PTV margins added for SBRT. While the rectum D5cm3 for HDR-BT and SBRT was 30.7 and 38.3 Gy (P < 0.01) and V40 was 16.3 and 20.8 cm3 (P < 0.01), respectively, SBRT was significantly superior in almost all dosimetric profiles for the bladder and urethra. These results suggest that SBRT as an alternative to HDR-BT in hypofractionated radiotherapy for prostate cancer might have an advantage for bladder and urethra dose sparing, but for the rectum only when proper PTV margins for SBRT are adopted. PMID:24957754

  14. Implementation of Fiducial-Based Image Registration in the Cyberknife Robotic System

    SciTech Connect

    Saw, Cheng B. Chen Hungcheng; Wagner, Henry

    2008-07-01

    Fiducial-based image registration methodology as implemented in the Cyberknife system is explored. The Cyberknife is a radiosurgery system that uses image guidance technology and computer-controlled robotics to determine target positions and adjust beam directions accordingly during the dose delivery. The image guidance system consists of 2 x-ray sources mounted on the ceiling and a detection system mounted on both sides of the treatment couch. Two orthogonal live radiographs are taken prior to and during patient treatment. Fiducial markers are identified on these radiographs and compared to a library of digital reconstructed radiographs (DRRs) using the fiducial extraction software. The fiducial extraction software initially sets an intensity threshold on the live radiographs to generate white areas on black images referred to as 'blobs.' Different threshold values are being used and blobs at the same location are assumed to originate from the same object. The number of blobs is then reduced by examining each blob against a predefined set of properties such as shape and exposure levels. The remaining blobs are further reduced by examining the location of the blobs in the inferior-superior patient axis. Those blobs that have the corresponding positions are assumed to originate from the same object. The remaining blobs are used to create fiducial configurations and are compared to the reference configuration from the computed tomography (CT) image dataset for treatment planning. The best-fit configuration is considered to have the appropriate fiducial markers. The patient position is determined based on these fiducial markers. During the treatment, the radiation beam is turned off when the Cyberknife changes nodes. This allows a time window to acquire live radiographs for the determination of the patient target position and to update the robotic manipulator to change beam orientations accordingly.

  15. Radiation shielding evaluation based on five years of data from a busy CyberKnife center.

    PubMed

    Yang, Jun; Feng, Jing

    2014-11-08

    We examined the adequacy of existing shielding guidelines using five-year clinical data from a busy CyberKnife center. From June 2006 through July 2011, 1,370 patients were treated with a total of 4,900 fractions and 680,691 radiation beams using a G4 CyberKnife. Prescription dose and total monitor units (MU) were analyzed to estimate the shielding workload and modulation factor. In addition, based on the beam's radiation source position, targeting position, MU, and beam collimator size, the MATLAB program was used to project each beam toward the shielding barrier. The summation of the projections evaluates the distribution of the shielding load. On average, each patient received 3.6 fractions, with an average 9.1 Gy per fraction prescribed at the 71.1% isodose line, using 133.7 beams and 6,200 MU. Intracranial patients received an average of 2.7 fractions, with 8.6 Gy per fraction prescribed at the 71.4% isodose line, using 133 beams and 5,083 MU. Extracranial patients received an average of 3.94 fractions, with 9.2 Gy per frac- tion prescribed at the 71% isodose line, using 134 beams and 6,514 MU. Most- used collimator sizes for intracranial patients were smaller (7.5 to 20 mm) than for extracranial patients (20 to 40 mm). Eighty-five percent of the beams exited through the floor, and about 40% of the surrounding wall area received no direct beam. For the rest of the wall, we found "hot" areas that received above-average MU. The locations of these areas were correlated with the projection of the nodes for extracranial treatments. In comparison, the beam projections on the wall were more spread for intracranial treatments. The maximum MU any area received from intracranial treatment was less than 0.25% of total MU used for intracranial treatments, and was less than 1.2% of total MU used for extracranial treatments. The combination of workload, modulation factor, and use factor in our practice are about tenfold less than recommendations in the existing CyberKnife

  16. Dosimetric characterization of CyberKnife radiosurgical photon beams using polymer gels

    SciTech Connect

    Pantelis, E.; Antypas, C.; Petrokokkinos, L.; Karaiskos, P.; Papagiannis, P.; Kozicki, M.; Georgiou, E.; Sakelliou, L.; Seimenis, I.

    2008-06-15

    Dose distributions registered in water equivalent, polymer gel dosimeters were used to measure the output factors and off-axis profiles of the radiosurgical photon beams employed for CyberKnife radiosurgery. Corresponding measurements were also performed using a shielded silicon diode commonly employed for CyberKnife commissioning, the PinPoint ion chamber, and Gafchromic EBT films, for reasons of comparison. Polymer gel results of this work for the output factors of the 5, 7.5, and 10 mm diameter beams are (0.702{+-}0.029), (0.872{+-}0.039), and (0.929{+-}0.041), respectively. Comparison of polymer gel and diode measurements shows that the latter overestimate output factors of the two small beams (5% for the 5 mm beam and 3% for the 7.5 mm beams). This is attributed to the nonwater equivalence of the high atomic number silicon material of the diode detector. On the other hand, the PinPoint chamber is found to underestimate output factors up to 10% for the 5 mm beam due to volume averaging effects. Polymer gel and EBT film output factor results are found in close agreement for all beam sizes, emphasizing the importance of water equivalence and fine detector sensitive volume for small field dosimetry. Relative off-axis profile results are in good agreement for all dosimeters used in this work, with noticeable differences observed only in the PinPoint estimate of the 80%-20% penumbra width, which is relatively overestimated.

  17. Image guidance quality assurance of a G4 CyberKnife robotic stereotactic radiosurgery system

    NASA Astrophysics Data System (ADS)

    Pantelis, E.; Petrokokkinos, L.; Antypas, C.

    2009-05-01

    The image guidance of a CyberKnife robotic radiosurgery system was quality controlled, including the overall performance of the target locating subsystem and the performance of the x-ray generators and flat panel digital cameras subcomponents. Accuracy and precision of the kV and exposure time settings of the x-ray generators, linearity of the x-ray output, spatial resolution and geometrical distortion of the acquired x-ray images were measured. Total accuracy and precision of the target locating subsystem in defining the position of an anthropomorphic head and neck phantom placed on treatment couch was also measured. Accuracy and precision of the kV as well as exposure time settings and linearity of the x-ray output were found within the acceptance limits suggested in diagnostic radiology. The acquired x-ray images were found to depict the shapes of the imaging objects without any geometrical distortion, being able to resolve differences in the features of imaging objects with critical frequency of 1.3 lp/mm and 1.5 lp/mm for camera A and B, respectively. Total target locating system accuracy was found within 0.2 mm and 0.2° in translations and rotations, respectively. Corresponding precision was found lower than 0.5%. These findings render the target locating subsystem of the CyberKnife capable of accurately registering the patient to treatment position and monitoring patient's movement during treatment delivery.

  18. Correlation and prediction uncertainties in the CyberKnife Synchrony respiratory tracking system

    SciTech Connect

    Pepin, Eric W.; Wu, Huanmei; Zhang, Yuenian; Lord, Bryce

    2011-07-15

    Purpose: The CyberKnife uses an online prediction model to improve radiation delivery when treating lung tumors. This study evaluates the prediction model used by the CyberKnife radiation therapy system in terms of treatment margins about the gross tumor volume (GTV). Methods: From the data log files produced by the CyberKnife synchrony model, the uncertainty in radiation delivery can be calculated. Modeler points indicate the tracked position of the tumor and Predictor points predict the position about 115 ms in the future. The discrepancy between Predictor points and their corresponding Modeler points was analyzed for 100 treatment model data sets from 23 de-identified lung patients. The treatment margins were determined in each anatomic direction to cover an arbitrary volume of the GTV, derived from the Modeler points, when the radiation is targeted at the Predictor points. Each treatment model had about 30 min of motion data, of which about 10 min constituted treatment time; only these 10 min were used in the analysis. The frequencies of margin sizes were analyzed and truncated Gaussian normal functions were fit to each direction's distribution. The standard deviation of each Gaussian distribution was then used to describe the necessary margin expansions in each signed dimension in order to achieve the desired coverage. In this study, 95% modeler point coverage was compared to 99% modeler coverage. Two other error sources were investigated: the correlation error and the targeting error. These were added to the prediction error to give an aggregate error for the CyberKnife during treatment of lung tumors. Results: Considering the magnitude of 2{sigma} from the mean of the Gaussian in each signed dimension, the margin expansions needed for 95% modeler point coverage were 1.2 mm in the lateral (LAT) direction and 1.7 mm in the anterior-posterior (AP) direction. For the superior-inferior (SI) direction, the fit was poor; but empirically, the expansions were 3.5 mm

  19. Virtual HDR{sup SM} CyberKnife Treatment for Localized Prostatic Carcinoma: Dosimetry Comparison With HDR Brachytherapy and Preliminary Clinical Observations

    SciTech Connect

    Fuller, Donald B. Naitoh, John; Lee, Charles; Hardy, Steven C.; Jin, Haoran

    2008-04-01

    Background: We tested our ability to approximate the dose (38 Gy), fractionation (four fractions), and distribution of high-dose-rate (HDR) brachytherapy for prostate cancer with CyberKnife (CK) stereotactic body radiotherapy (SBRT) plans. We also report early clinical observations of CK SBRT treatment. Methods and Materials: Ten patients were treated with CK. For each CK SBRT plan, an HDR plan was designed using common contour sets and simulated HDR catheters. Planning target volume coverage, intraprostatic dose escalation, and urethra, rectum, and bladder exposure were compared. Results: Planning target volume coverage by the prescription dose was similar for CK SBRT and HDR plans, whereas percent of volume of interest receiving 125% of prescribed radiation dose (V125) and V150 values were higher for HDR, reflecting higher doses near HDR source dwell positions. Urethra dose comparisons were lower for CK SBRT in 9 of 10 cases, suggesting that CK SBRT may more effectively limit urethra dose. Bladder maximum point doses were higher with HDR, but bladder dose falloff beyond the maximum dose region was more rapid with HDR. Maximum rectal wall doses were similar, but CK SBRT created sharper rectal dose falloff beyond the maximum dose region. Second CK SBRT plans, constructed by equating urethra radiation dose received by point of maximum exposure of volume of interest to the HDR plan, significantly increased V125 and V150. Clinically, 4-month post-CK SBRT median prostate-specific antigen levels decreased 86% from baseline. Acute toxicity was primarily urologic and returned to baseline by 2 months. Acute rectal morbidity was minimal and transient. Conclusions: It is possible to construct CK SBRT plans that closely recapitulate HDR dosimetry and deliver the plans noninvasively.

  20. Integral dose: Comparison between four techniques for prostate radiotherapy

    PubMed Central

    Ślosarek, Krzysztof; Osewski, Wojciech; Grządziel, Aleksandra; Radwan, Michał; Dolla, Łukasz; Szlag, Marta; Stąpór-Fudzińska, Małgorzata

    2014-01-01

    Aim Comparisons of integral dose delivered to the treatment planning volume and to the whole patient body during stereotactic, helical and intensity modulated radiotherapy of prostate. Background Multifield techniques produce large volumes of low dose inside the patient body. Delivered dose could be the result of the cytotoxic injuries of the cells even away from the treatment field. We calculated the total dose absorbed in the patient body for four radiotherapy techniques to investigate whether some methods have a potential to reduce the exposure to the patient. Materials and methods We analyzed CyberKnife plans for 10 patients with localized prostate cancer. Five alternative plans for each patient were calculated with the VMAT, IMRT and TomoTherapy techniques. Alternative dose distributions were calculated to achieve the same coverage for PTV. Integral Dose formula was used to calculate the total dose delivered to the PTV and whole patient body. Results Analysis showed that the same amount of dose was deposited to the treated volume despite different methods of treatment delivery. The mean values of total dose delivered to the whole patient body differed significantly for each treatment technique. The highest integral dose in the patient's body was at the TomoTherapy and CyberKnife treatment session. VMAT was characterized by the lowest integral dose deposited in the patient body. Conclusions The highest total dose absorbed in normal tissue was observed with the use of a robotic radiosurgery system and TomoTherapy. These results demonstrate that the exposure of healthy tissue is a dosimetric factor which differentiates the dose delivery methods. PMID:25859398

  1. Patterns of care of radiotherapy in México

    PubMed Central

    Poitevin-Chacón, Adela; Hinojosa-Gómez, José

    2012-01-01

    Aim This survey is performed to learn about the structure of radiotherapy in México. Background Radiation oncology practice is increasing because of the higher incidence of cancer. There is no published data about radiotherapy in México. Materials and methods A questionnaire was sent to the 83 registered centers in the database of the Mexican regulatory agency. One out of the 32 states has no radiotherapy. 27 centers from 14 states provided their answers. Results 829 patients are treated annually with any radiotherapy modality in each center. Two centers have one cobalt machine, 7 have a cobalt and a linac and 10 have more than one linac. Five centers use 2D planning systems, 22 use 3D; 9, conventional simulators; 22, CT based simulation, and 1 center has no simulation. Most of the centers verify beams with films, electronic portal image devices and cone beam CTs are also used. Intensity modulated and image guided radiotherapy are performed in 5 states. Breast, prostate, cervix, lung, rectum and head and neck cancer are the six most common locations. There are 45 public and 38 private centers, 2 dedicated to children. Two gamma knife units, 5 Novalis systems, 1 tomotherapy and 2 cyberknife machines are working. All centers have at least one radiation oncologist, one physicist and one radiotherapist. Conclusions Definitive conclusions cannot be drawn from this limited feedback due to a low participation of centers. This survey about radiotherapy in Mexico shows the heterogeneity of equipment as well as medical and technical staff in the whole country. PMID:24416531

  2. Quality of life in the follow-up of uveal melanoma patients after CyberKnife treatment.

    PubMed

    Klingenstein, Annemarie; Fürweger, Christoph; Nentwich, Martin M; Schaller, Ulrich C; Foerster, Paul I; Wowra, Berndt; Muacevic, Alexander; Eibl, Kirsten H

    2013-12-01

    To assess quality of life in uveal melanoma patients within the first and second year after CyberKnife radiosurgery. Overall, 91 uveal melanoma patients were evaluated for quality of life through the Short-form (SF-12) Health Survey at baseline and at every follow-up visit over 2 years after CyberKnife radiosurgery. Statistical analysis was carried out using SF Health Outcomes Scoring Software and included subgroup analysis of patients developing secondary glaucoma and of patients maintaining a best corrected visual acuity (BCVA) of the treated eye of 0.5 log(MAR) or better. Analysis of variance, Greenhouse-Geisser correction, Student's t-test, and Fisher's exact test were used to determine statistical significance. Physical Functioning (PF) and Role Physical (RP) showed a significant decrease after CyberKnife radiosurgery, whereas Mental Health (MH) improved (P=0.007, P<0.0001 and P=0.023). MH and Social Functioning (SF) increased significantly (P=0.0003 and 0.026) in the no glaucoma group, MH being higher compared with glaucoma patients (P=0.02). PF and RP were significantly higher in patients with higher BCVA at the second follow-up (P=0.02). RP decreased in patients with BCVA<0.5 log(MAR) (P=0.013). Vitality (VT) increased significantly in patients whose BCVA could be preserved (P=0.031). Neither tumor localization nor size influenced the development of secondary glaucoma or change in BCVA. Although PF and RP decreased over time, MH improved continuously. Prevention of secondary glaucoma has a significant influence on both SF and MH, whereas preservation of BCVA affects VT. Emotional stability throughout follow-up contributes positively toward overall quality of life. CyberKnife radiosurgery may contribute to attenuation of emotional distress in uveal melanoma patients.

  3. Radiotherapy Accidents

    NASA Astrophysics Data System (ADS)

    Mckenzie, Alan

    A major benefit of a Quality Assurance system in a radiotherapy centre is that it reduces the likelihood of an accident. For over 20 years I have been the interface in the UK between the Institute of Physics and Engineering in Medicine and the media — newspapers, radio and TV — and so I have learned about radiotherapy accidents from personal experience. In some cases, these accidents did not become public and so the hospital cannot be identified. Nevertheless, lessons are still being learned.

  4. Fiducial migration following small peripheral lung tumor image-guided CyberKnife stereotactic radiosurgery

    NASA Astrophysics Data System (ADS)

    Strulik, Konrad L.; Cho, Min H.; Collins, Brian T.; Khan, Noureen; Banovac, Filip; Slack, Rebecca; Cleary, Kevin

    2008-03-01

    To track respiratory motion during CyberKnife stereotactic radiosurgery in the lung, several (three to five) cylindrical gold fiducials are implanted near the planned target volume (PTV). Since these fiducials remain in the human body after treatment, we hypothesize that tracking fiducial movement over time may correlate with the tumor response to treatment and pulmonary fibrosis, thereby serving as an indicator of treatment success. In this paper, we investigate fiducial migration in 24 patients through examination of computed tomography (CT) volume images at four time points: pre-treatment, three, six, and twelve month post-treatment. We developed a MATLAB based GUI environment to display the images, identify the fiducials, and compute our performance measure. After we semi-automatically segmented and detected fiducial locations in CT images of the same patient over time, we identified them according to their configuration and introduced a relative performance measure (ACD: average center distance) to detect their migration. We found that the migration tended to result in a movement towards the fiducial center of the radiated tissue area (indicating tumor regression) and may potentially be linked to the patient prognosis.

  5. Analysis of high–dose rate brachytherapy dose distribution resemblance in CyberKnife hypofractionated treatment plans of localized prostate cancer

    SciTech Connect

    Sudahar, H.; Kurup, P.G.G.; Murali, V.; Mahadev, P.; Velmurugan, J.

    2013-01-01

    The present study is to analyze the CyberKnife hypofractionated dose distribution of localized prostate cancer in terms of high–dose rate (HDR) brachytherapy equivalent doses to assess the degree of HDR brachytherapy resemblance of CyberKnife dose distribution. Thirteen randomly selected localized prostate cancer cases treated using CyberKnife with a dose regimen of 36.25 Gy in 5 fractions were considered. HDR equivalent doses were calculated for 30 Gy in 3 fractions of HDR brachytherapy regimen. The D{sub 5%} of the target in the CyberKnife hypofractionation was 41.57 ± 2.41 Gy. The corresponding HDR fractionation (3 fractions) equivalent dose was 32.81 ± 1.86 Gy. The mean HDR fractionation equivalent dose, D{sub 98%}, was 27.93 ± 0.84 Gy. The V{sub 100%} of the prostate target was 95.57% ± 3.47%. The V{sub 100%} of the bladder and the rectum were 717.16 and 79.6 mm{sup 3}, respectively. Analysis of the HDR equivalent dose of CyberKnife dose distribution indicates a comparable resemblance to HDR dose distribution in the peripheral target doses (D{sub 98%} to D{sub 80%}) reported in the literature. However, there is a substantial difference observed in the core high-dose regions especially in D{sub 10%} and D{sub 5%}. The dose fall-off within the OAR is also superior in reported HDR dose distribution than the HDR equivalent doses of CyberKnife.

  6. SU-E-T-409: Intensity Modulated Robotic Radiotherapy

    SciTech Connect

    Wang, B; Jin, L; Li, J; Chen, L; Ma, C; Fan, J; Zhang, C

    2014-06-01

    Purpose: As compared with the IRIS-based models, the MLC-based CyberKnife system allows more efficient treatment delivery due to its improved coverage of large lesions and intensity modulation. The treatment delivery efficiency is mainly determined by the number of selected nodes. This study aimed to demonstrate that relatively small sets of optimally selected nodes could produce high-quality plans. Methods: The full body path of the CyberKnife system consists of 110 nodes, from which we selected various sets for 4 prostate cancer cases using our in-house beamselection software. With the selected nodes we generated IMRT plans using our in-house beamlet-based inverse-planning optimization program. We also produced IMRT plans using the MultiPlan treatment planning system (version 5.0) for the same cases. Furthermore, the nodes selected by MultiPlan were used to produce plans with our own optimization software so that we could compare the quality of the selected sets of nodes. Results: Our beam-selection program selected one node-set for each case, with the number of nodes ranging from 23 to 34. The IMRT plans based on the selected nodes and our in-house optimization program showed adequate target coverage, with favorable critical structure sparing for the cases investigated. Compared with the plans using the nodes selected by MultiPlan, the plans generated with our selected beams provided superior rectum/bladder sparing for 75% of the cases. The plans produced by MultiPlan with various numbers of nodes also suggested that the plan quality was not compromised significantly when the number of nodes was reduced. Conclusion: Our preliminary results showed that with beamletbased planning optimization, one could produce high-quality plans with an optimal set of nodes for MLC-based robotic radiotherapy. Furthermore, our beam-selection strategy could help further improve critical structure sparing.

  7. SU-E-T-228: Liquid Ionisation Chamber Array and MicroDiamond Measurements with the CyberKnife System

    SciTech Connect

    Poppinga, D; Looe, H; Stelljes, T; Poppe, B; Blanck, O; Harder, D

    2014-06-01

    Purpose: The aim of this study was to measure the dose profile and output factors with a CyberKnife accelerator using a TM60019 microDiamond detector and a 1000SRS liquid chamber array (both PTW Freiburg, Germany). Methods: An MP3 water phantom (PTW, Freiburg) was positioned along the robotic world coordinate system. The TM60019 detector was adjusted to the center of the according fields and the semiconductor axis was aligned with the beam direction. Profiles at 5cm water depth and SSD = 80 cm were measured along the robotic x axis and y axis for the cylindrical collimators of the CyberKnife (diameter 60, 50, 40, 30, 20, 15, 12.5, 10, 7.5 and 5mm). To determine the output factors the dose profile was measured at 0.1 mm steps around the field center to find the maximum dose value. The liquid chamber array (1000SRS) measurement was performed with the same setup, but with RW3 buildup. Results: The 1000SRS measurements closely conform with the TM60019 profile measurement in all profile regions and for all collimator sizes. The profile measurement is influenced by the almost equal spatial resolution of the TM60019 detector (radius of the sensitive area 1.1mm) and of the 1000SRS liquid chamber array (single chamber width 2.3mm). The measured dose profiles have not been corrected for this limited spatial resolution. Rather we purpose to consider that spatial dose averaging over 2 mm wide regions might be justified in view of patient positioning inaccuracies and of the spaces in tissue participating in the biological radiation responses. Conclusion: The 1000SRS data points conform with the TM60019 profile measurements at all profile regions showing the applicability of liquid ion chamber arrays with the CyberKnife system.

  8. Stereotactic Body Radiotherapy (SBRT) for Intrahepatic and Hilar Cholangiocarcinoma

    PubMed Central

    Mahadevan, Anand; Dagoglu, Nergiz; Mancias, Joseph; Raven, Kristin; Khwaja, Khalid; Tseng, Jennifer F; Ng, Kimmie; Enzinger, Peter; Miksad, Rebecca; Bullock, Andrea; Evenson, Amy

    2015-01-01

    Background: Unresectable intrahepatic and hilar cholangiocarcinomas carry a dismal prognosis. Systemic chemotherapy and conventional external beam radiation and brachytherapy have been used with limited success. We explored the use of stereotactic body radiotherapy (SBRT) for these patients. Methods: Patients with unresectable intrahepatic or hilar cholangiocarcinoma or those with positive margins were included in this study. Systemic therapy was used at the discretion of the medical oncologist. The CyberknifeTM stereotactic body radiotherapy system used to treat these patients. Patients were treated with three daily fractions. Clinical and radiological follow-up were performed every three months. Results: 34 patients (16 male and 18 female) with 42 lesions were included in this study. There were 32 unresectable tumors and two patients with resected tumors with positive margins. The median SBRT dose was 30Gy in three fractions. The median follow-up was 38 months (range 8-71 months). The actuarial local control rate was 79%. The median overall survival was 17 months and the median progression free survival was ten months. There were four Grade III toxicities (12%), including duodenal ulceration, cholangitis and liver abscess. Conclusions: SBRT is an effective and reasonably safe local therapy option for unresectable intrahepatic or hilar cholangiocarcinoma. PMID:26516357

  9. SU-E-T-258: Parallel Optimization of Beam Configurations for CyberKnife Treatments

    SciTech Connect

    Viulet, T; Blanck, O; Schlaefer, A

    2014-06-01

    Purpose: The CyberKnife delivers a large number of beams originating at different non-planar positions and with different orientation. We study how much the quality of treatment plans depends on the beams considered during plan optimization. Particularly, we evaluate a new approach to search for optimal treatment plans in parallel by running optimization steps concurrently. Methods: So far, no deterministic, complete and efficient method to select the optimal beam configuration for robotic SRS/SBRT is known. Considering a large candidate beam set increases the likelihood to achieve a good plan, but the optimization problem becomes large and impractical to solve. We have implemented an approach that parallelizes the search by solving multiple linear programming problems concurrently while iteratively resampling zero weighted beams. Each optimization problem contains the same set of constraints but different variables representing candidate beams. The search is synchronized by sharing the resulting basis variables among the parallel optimizations. We demonstrate the utility of the approach based on an actual spinal case with the objective to improve the coverage. Results: The objective function is falling and reaches a value of 5000 after 49, 31, 25 and 15 iterations for 1, 2, 4, and 8 parallel processes. This corresponds to approximately 97% coverage in 77%, 59%, and 36% of the mean number of iterations with one process for 2, 4, and 8 parallel processes, respectively. Overall, coverage increases from approximately 91.5% to approximately 98.5%. Conclusion: While on our current computer with uniform memory access the reduced number of iterations does not translate into a similar speedup, the approach illustrates how to effectively parallelize the search for the optimal beam configuration. The experimental results also indicate that for complex geometries the beam selection is critical for further plan optimization.

  10. SU-E-T-516: Measurement of the Absorbed Dose Rate in Water Under Reference Conditions in a CyberKnife Unit

    SciTech Connect

    Aragon-Martinez, N; Hernandez-Guzman, A; Gomez-Munoz, A; Massillon-JL, G

    2014-06-01

    Purpose: This paper aims to measure the absorbed-dose-rate in a CyberKnife unit reference-field (6cm diameter) using three ionization chambers (IC) following the new IAEA/AAPM formalism and Gafchromic film (MD-V3-55 and EBT3) protocol according to our work reported previously. Methods: The absorbed-dose-rates were measured at 90cm and 70cm SSD in a 10cmx10cm field and at 70cm SSD in a 5.4cmx5.4cm equivalent to 6cm diameter field using a linac Varian iX. All measurements were performed at 10cm depth in water. The correction factors that account for the difference between the IC response on the reference field and the CyberKnife reference field, k-(Q-msr,Q)^(f-msr,f-ref), were evaluated and Gafchromic film were calibrated using the results obtained above. Under the CyberKnife reference conditions, the factors were used to measure the absorbed-dose-rate with IC according to the new formalism and the calibrated film was irradiated in water. The film calibration curve was used to evaluate the absorbed-dose-rate in the CyberKnife unit. Results: Difference up to 2.56% is observed between dose-rate measured with IC in the reference 10cmx10cm field, depending where the chamber was calibrated, which was not reflected in the correction factor k-(Q-msr,Q)^(f-msr,f-ref ) where variations of ~0.15%-0.5% were obtained. Within measurements uncertainties, maximum difference of 1.8% on the absorbed-dose-rate in the CyberKnife reference field is observed between all IC and the films Conclusion: Absorbed-dose-rate to water was measured in a CyberKnife reference field with acceptable accuracy (combined uncertainties ~1.32%-1.73%, k=1) using three IC and films. The MD-V3-55 film as well as the new IAEA/AAPM formalism can be considered as a suitable dosimetric method to measure absorbed-dose-rate to water in small and non-standard CyberKnife fields used in clinical treatments However, the EBT3 film is not appropriated due to the high uncertainty provided (combined uncertainty ~9%, k=1

  11. Real time tracking in liver SBRT: comparison of CyberKnife and Vero by planning structure-based γ-evaluation and dose-area-histograms

    NASA Astrophysics Data System (ADS)

    Sothmann, T.; Blanck, O.; Poels, K.; Werner, R.; Gauer, T.

    2016-02-01

    The purpose of this study was to evaluate and compare two clinical tracking systems for radiosurgery with regard to their dosimetric and geometrical accuracy in liver SBRT: the robot-based CyberKnife and the gimbal-based Vero. Both systems perform real-time tumour tracking by correlating internal tumour and external surrogate motion. CyberKnife treatment plans were delivered to a high resolution 2D detector array mounted on a 4D motion platform, with the platform simulating (a) tumour motion trajectories extracted from the corresponding CyberKnife predictor log files and (b) the tumour motion trajectories with superimposed baseline-drift. Static reference and tracked dose measurements were compared and dosimetric as well as geometrical uncertainties analyzed by a planning structure-based evaluation. For (a), γ-passing rates inside the CTV (γ-criteria of 1% / 1 mm) ranged from 95% to 100% (CyberKnife) and 98% to 100% (Vero). However, dosimetric accuracy decreases in the presence of the baseline-drift. γ-passing rates for (b) ranged from 26% to 92% and 94% to 99%, respectively; i.e. the effect was more pronounced for CyberKnife. In contrast, the Vero system led to maximum dose deviations in the OAR between  +1.5 Gy to  +6.0 Gy (CyberKnife:  +0.5 Gy to  +3.5 Gy). Potential dose shifts were interpreted as motion-induced geometrical tracking errors. Maximum observed shift ranges were  -1.0 mm to  +0.7 mm (lateral) /-0.6 mm to  +0.1 mm (superior-inferior) for CyberKnife and  -0.8 mm to  +0.2 mm /-0.8 mm to  +0.4 mm for Vero. These values illustrate that CyberKnife and Vero provide high precision tracking of regular breathing patterns. Even for the modified motion trajectory, the obtained dose distributions appear to be clinical acceptable with regard to literature QA γ-criteria of 3% / 3 mm.

  12. SU-E-J-199: Evaluation of Motion Tracking Effects On Stereotactic Body Radiotherapy of Abdominal Targets

    SciTech Connect

    Monterroso, M; Dogan, N; Yang, Y

    2014-06-01

    Purpose: To evaluate the effects of respiratory motion on the delivered dose distribution of CyberKnife motion tracking-based stereotactic body radiotherapy (SBRT) of abdominal targets. Methods: Four patients (two pancreas and two liver, and all with 4DCT scans) were retrospectively evaluated. A plan (3D plan) using CyberKnife Synchrony was optimized on the end-exhale phase in the CyberKnife's MultiPlan treatment planning system (TPS), with 40Gy prescribed in 5 fractions. A 4D plan was then created following the 4D planning utility in the MultiPlan TPS, by recalculating dose from the 3D plan beams on all 4DCT phases, with the same prescribed isodose line. The other seven phases of the 4DCT were then deformably registered to the end-exhale phase for 4D dose summation. Doses to the target and organs at risk (OAR) were compared between 3D and 4D plans for each patient. The mean and maximum doses to duodenum, liver, spinal cord and kidneys, and doses to 5cc of duodenum, 700cc of liver, 0.25cc of spinal cord and 200cc of kidneys were used. Results: Target coverage in the 4D plans was about 1% higher for two patients and about 9% lower in the other two. OAR dose differences between 3D and 4D varied among structures, with doses as much as 8.26Gy lower or as much as 5.41Gy higher observed in the 4D plans. Conclusion: The delivered dose can be significantly different from the planned dose for both the target and OAR close to the target, which is caused by the relative geometry change while the beams chase the moving target. Studies will be performed on more patients in the future. The differences of motion tracking versus passive motion management with the use of internal target volumes will also be investigated.

  13. CyberKnife radiosurgery for brainstem metastases: Management and outcomes and a review of the literature.

    PubMed

    Liu, Szu-Hao; Murovic, Judith; Wallach, Jonathan; Cui, Guosheng; Soltys, Scott G; Gibbs, Iris C; Chang, Steven D

    2016-03-01

    To our knowledge this paper is the first to use recursive partitioning analysis (RPA) for brainstem metastasis (BSM) patient outcomes, after CyberKnife radiosurgery (CKRS; Accuray, Sunnyvale, CA, USA); nine similar previous publications used mainly Gamma Knife radiosurgery (Elekta AB, Stockholm, Sweden). Retrospective chart reviews from 2006-2013 of 949 CKRS-treated brain metastasis patients showed 54 BSM patients (5.7%): 35 RPA Class II (65%) and 19 Class III (35%). There were 30 women (56%) and 24 men (44%). The median age was 59 years (range 36-80) and median follow-up was 5 months (range 1-52). Twenty-three patients (43%) had lung carcinoma BSM and 12 (22%) had breast cancer BSM. Fifty-four RPA Class II and III BSM patients had a median overall survival (OS) of 5 months, and for each Class 8 and 2 months, respectively. Of 36 RPA Class II and III patients with available symptoms (n=31) and findings (n=33), improvement/stability occurred in the majority for symptoms (86%) and findings (92%). Of 35 cases, 28 (80%) achieved BSM local control (LC); 13/14 with breast histology (93%) and 10/13 with lung histology (77%). All six RPA Class II and III patients with controlled extracranial systemic disease (ESD) experienced LC. Median tumor volume was 0.14 cm(3); of 34 RPA Class II and III cases, 26 LC patients had a 0,13 cm(3) median tumor volume while it was 0.27 cm(3) in the eight local failures. Of 35 cases, single session equivalent dosages less than the median (n=13), at the 17.9 Gy median (n=5) and greater than the median (n=17) had BSM LC in 10 (77%), four (80%) and 14 cases (82%), respectively. Univariate analysis showed Karnofsky Performance Score, RPA Class and ESD-control predicted OS. CKRS is useful for RPA Class II and III BSM patients with effective clinical and local BSM control.

  14. Split-Volume Treatment Planning of Multiple Consecutive Vertebral Body Metastases for Cyberknife Image-Guided Robotic Radiosurgery

    SciTech Connect

    Sahgal, Arjun Chuang, Cynthia; Larson, David; Huang, Kim; Petti, Paula; Weinstein, Phil; Ma Lijun

    2008-10-01

    Cyberknife treatment planning of multiple consecutive vertebral body metastases is challenging due to large target volumes adjacent to critical normal tissues. A split-volume treatment planning technique was developed to improve the treatment plan quality of such lesions. Treatment plans were generated for 1 to 5 consecutive thoracic vertebral bodies (CVBM) prescribing a total dose of 24 Gy in 3 fractions. The planning target volume (PTV) consisted of the entire vertebral body(ies). Treatment plans were generated considering both the de novo clinical scenario (no prior radiation), imposing a dose limit of 8 Gy to 1 cc of spinal cord, and the retreatment scenario (prior radiation) with a dose limit of 3 Gy to 1 cc of spinal cord. The split-volume planning technique was compared with the standard full-volume technique only for targets ranging from 2 to 5 CVBM in length. The primary endpoint was to obtain best PTV coverage by the 24 Gy prescription isodose line. A total of 18 treatment plans were generated (10 standard and 8 split-volume). PTV coverage by the 24-Gy isodose line worsened consistently as the number of CVBM increased for both the de novo and retreatment scenario. Split-volume planning was achieved by introducing a 0.5-cm gap, splitting the standard full-volume PTV into 2 equal length PTVs. In every case, split-volume planning resulted in improved PTV coverage by the 24-Gy isodose line ranging from 4% to 12% for the de novo scenario and, 8% to 17% for the retreatment scenario. We did not observe a significant trend for increased monitor units required, or higher doses to spinal cord or esophagus, with split-volume planning. Split-volume treatment planning significantly improves Cyberknife treatment plan quality for CVBM, as compared to the standard technique. This technique may be of particular importance in clinical situations where stringent spinal cord dose limits are required.

  15. Evaluation of tracking accuracy of the CyberKnife system using a webcam and printed calibrated grid.

    PubMed

    Sumida, Iori; Shiomi, Hiroya; Higashinaka, Naokazu; Murashima, Yoshikazu; Miyamoto, Youichi; Yamazaki, Hideya; Mabuchi, Nobuhisa; Tsuda, Eimei; Ogawa, Kazuhiko

    2016-01-01

    Tracking accuracy for the CyberKnife's Synchrony system is commonly evaluated using a film-based verification method. We have evaluated a verification system that uses a webcam and a printed calibrated grid to verify tracking accuracy over three different motion patterns. A box with an attached printed calibrated grid and four fiducial markers was attached to the motion phantom. A target marker was positioned at the grid's center. The box was set up using the other three markers. Target tracking accuracy was evaluated under three conditions: 1) stationary; 2) sinusoidal motion with different amplitudes of 5, 10, 15, and 20 mm for the same cycle of 4 s and different cycles of 2, 4, 6, and 8 s with the same amplitude of 15 mm; and 3) irregular breathing patterns in six human volunteers breathing normally. Infrared markers were placed on the volunteers' abdomens, and their trajectories were used to simulate the target motion. All tests were performed with one-dimensional motion in craniocaudal direction. The webcam captured the grid's motion and a laser beam was used to simulate the CyberKnife's beam. Tracking error was defined as the difference between the grid's center and the laser beam. With a stationary target, mean tracking error was measured at 0.4 mm. For sinusoidal motion, tracking error was less than 2 mm for any amplitude and breathing cycle. For the volunteers' breathing patterns, the mean tracking error range was 0.78-1.67 mm. Therefore, accurate lesion targeting requires individual quality assurance for each patient. PMID:27074474

  16. SU-E-J-64: Feasibility Study of Surgical Clips for Fiducial Tracking in CyberKnife System

    SciTech Connect

    Lee, H; Yoon, J; Lee, E; Cho, S; Park, K; Choi, W; Baek, J; Keum, K; Koom, W

    2015-06-15

    Purpose: To investigate the ability of CyberKnife to track surgical clips used as fiducial markers. Methods: The Octavius 1000SRS detector and solid water (RW3) slab phantom were used with motion platform to evaluate the study. The RW3 slab phantom was set up to measure the dose distribution from coronal plane. It consists of 9 plates and the thickness of each plate is 10mm. Among them, one plate was attached with 3 surgical clips, which are orthogonally positioned on outer region of array. The length of attached clip was represented as 1cm on planning CT. The clip plate was placed on the 1000SRS detector and 3 slabs were stacked up on the plate to build the measuring depth. Below the detector, 5 slabs were set. The two-axis motion platform was programmed with 1D sinusoidal movement (20mm peak-to-peak, 3s period) toward superior/inferior and left/right directions to simulate target motion. During delivery, two clips were extracted by two X-ray imagers, which led to translational error correction only. Synchrony was also used for dynamic tracking. After the irradiation, the measured dose distribution of coronal plane was compared with the planar dose distribution calculated by the CyberKnife treatment planning system (Multiplan) for cross verification. The results were assessed by comparing the absolute Gamma (γ) index. Results: The dose distributions measured by the 1000SRS detector were in good agreements with those calculated by Multiplan. In the dosimetric comparison using γ-function criteria based on the distance-to-agreement of 3mm and the local dose difference of 3%, the passing rate with γ- parameter ≤1 was 91% in coronal plane. Conclusion: The surgical clips can be considered as new fiducials for robotic radiosurgery delivery by considering the target margin with less than 5mm.

  17. SU-E-T-281: Reduction of Treatment Times in CyberKnife Prostate SBRT Using a Water Filled Rectal Balloon

    SciTech Connect

    Desai, P; Caroprese, B; McKellar, H

    2014-06-01

    Purpose: To illustrate 25% reduction in CyberKnife prostate SBRT treatment times using a water filled rectal balloon. Methods: We perform prostate SBRT using a 3800cGy in 4 fraction regimen prescribed between 51% 59% iso-dose lines to 95% of PTV using a CyberKnife System. The resultant heterogeneous dosimetry is analogous to HDR dosimetry. Our patients are treated in a feet first supine position to decrease treatment couch sag and also to position the prostate anatomy closer to the robot. CT imaging is performed with a Radiadyne Immobiloc rectal balloon filled with 45-50cc water placed firmly inside the patient's rectum. A treatment plan is developed from this CT study using Multiplan. The patient is treated every other day for 4 days using the rectal balloon for each fraction. Gold fiducials previously implanted inside the prostate are used for tracking by the CyberKnife system. Results: Critical structures comprise the usual GU anatomy of bladder, rectum, urethra, femoral-heads along with emphasis on doses to anterior rectal wall and rectal mucosa. The water filled rectal balloon localizes the rectum, which enables the physician to accurately contour both anterior rectal wall, and rectal mucosa. The balloon also has a gas release valve enabling better patient comfort. Rectum localization enables the CyberKnife system to make fewer corrections resulting in fewer treatment interruptions and time lost to re-adjustment for rectal motion, bowel filling and gas creation. Effective treatment times are reduced by 25% to approximately 45 minutes. Adoption of the balloon has required minimal change to our planning strategy and plan evaluation process. Conclusion: Patient follow-up comparisons show no difference in effectiveness of treatment with and without balloons We conclude that rectal balloons enhance patient comfort and decrease effective treatment times.

  18. Sci—Sat AM: Stereo — 09: Accuracy of Liver Cancer Treatment on Cyberknife® with Synchrony™ Optical Tracking Throughout the Respiratory Cycle

    SciTech Connect

    Winter, J.; Chow, T; Wong, R.

    2014-08-15

    The Cyberknife® robotic stereotactic body radiation therapy system is well-suited for treating liver lesions over the respiratory cycle as it includes room-mounted orthogonal x-ray tracking of internal fiducial markers and optical tracking of external markers. The Synchrony™ software generates a model of internal target positions during patient respiration and correlates it to the external optical tracking system for real-time optical-based position corrections of the linear accelerator during beam delivery. Although clinical studies have provided preliminary outcomes for liver lesions treated with the Cyberknife system, to date, there is little data demonstrating the ability of the Synchrony software to track targets in the liver, which deforms throughout the respiratory cycle. In this study, we investigated the respiratory motion model performance for predicting tumour motion. We conducted a retrospective analysis of fifteen liver cancer patients treated on the Cyberknife using the Synchrony optical tracking system. We analyzed Cyberknife tracking information stored in the log files to extract the left-right (LR), anterior-posterior (AP) and superior-inferior (SI) correlation errors between the model-predicted position and the internal fiducial centroid position determined by x-ray imaging. Only translational tracking and corrections were applied during treatment. Overall, the correlation errors were greatest in the SI direction. We calculated radial correlation errors, and determined that the 95{sup th}, 98{sup th} and 99{sup th} percentile errors were 3.4 mm, 4.4 mm and 5.1 mm, respectively. Based on translational correlation tracking errors we expect the clinical target volume will be within 3.4 mm of the planning target volume for 95 % of beam delivery time.

  19. Dosimetric comparison of Linac-based (BrainLAB®) and robotic radiosurgery (CyberKnife ®) stereotactic system plans for acoustic schwannoma.

    PubMed

    Dutta, Debnarayan; Balaji Subramanian, S; Murli, V; Sudahar, H; Gopalakrishna Kurup, P G; Potharaju, Mahadev

    2012-02-01

    A dosimetric comparison of linear accelerator (LA)-based (BrainLAB) and robotic radiosurgery (RS) (CyberKnife) systems for acoustic schwannoma (Acoustic neuroma, AN) was carried out. Seven patients with radiologically confirmed unilateral AN were planned with both an LA-based (BrainLAB) and robotic RS (CyberKnife) system using the same computed tomography (CT) dataset and contours. Gross tumour volume (GTV) was contoured on post-contrast magnetic resonance imaging (MRI) scan [planning target volume (PTV) margin 2 mm]. Planning and calculation were done with appropriate calculation algorithms. The prescribed isodose in both systems was considered adequate to cover at least 95% of the contoured target. Plan evaluations were done by examining the target coverage by the prescribed isodose line, and high- and low-dose volumes. Isodose plans and dose volume histograms generated by the two systems were compared. There was no statistically significant difference between the contoured volumes between the systems. Tumour volumes ranged from 380 to 3,100 mm(3). Dose prescription was 13-15 Gy in single fraction (median prescribed isodose 85%). There were no significant differences in conformity index (CI) (0.53 versus 0.58; P = 0.225), maximum brainstem dose (4.9 versus 4.7 Gy; P = 0.935), 2.5-Gy volume (39.9 versus 52.3 cc; P = 0.238) or 5-Gy volume (11.8 versus 16.8 cc; P = 0.129) between BrainLAB and CyberKnife system plans. There were statistically significant differences in organs at risk (OAR) doses, such as mean cochlear dose (6.9 versus 5.4 Gy; P = 0.001), mean mesial temporal dose (2.6 versus 1.7 Gy; P = 0.07) and high-dose (10 Gy) volume (3.2 versus 5.2 cc; P = 0.017). AN patients planned with the CyberKnife system had superior OAR (cochlea and mesial temporal lobe) sparing compared with those planned with the Linac-based system. Further evaluation of these findings in prospective studies with clinical correlation will provide actual clinical benefit from the

  20. [Radiotherapy for Thyroid Cancer].

    PubMed

    Jingu, Keiichi; Maruoka, Shin; Umezawa, Rei; Takahashi, Noriyoshi

    2015-06-01

    Radioactive 131I therapy for differentiated thyroid cancer has been used since the 1940s and is an established and effective treatment. In contrast, external beam radiotherapy (EBRT) was considered to be effective for achieving local control but not for prolonging survival. Although clinicians were hesitant to administer EBRT owing to the potential radiation-induced adverse effects of 2 dimensional (2D)-radiotherapy until 2000, it is expected that adverse effects will be reduced and treatment efficacy improved through the introduction of more advanced techniques for delivering radiation (eg, 3D-radiotherapy and intensity modulated radiotherapy [IMRT]). The prognosis of undifferentiated thyroid cancer is known to be extremely bad, although in very rare cases, multimodality therapy (total or subtotal resection, chemotherapy, and radiotherapy) has allowed long-term survival. Here, we report the preliminary results of using hypofractionated radiotherapy for undifferentiated thyroid cancer in our institution. PMID:26199238

  1. Correction factors for ionization chamber dosimetry in CyberKnife: Machine-specific, plan-class, and clinical fields

    SciTech Connect

    Gago-Arias, Araceli; Antolin, Elena; Fayos-Ferrer, Francisco; Simon, Rocio; Gonzalez-Castano, Diego M.; Palmans, Hugo; Sharpe, Peter; Gomez, Faustino; Pardo-Montero, Juan

    2013-01-15

    Purpose: The aim of this work is the application of the formalism for ionization chamber reference dosimetry of small and nonstandard fields [R. Alfonso, P. Andreo, R. Capote, M. S. Huq, W. Kilby, P. Kjaell, T. R. Mackie, H. Palmans, K. Rosser, J. Seuntjens, W. Ullrich, and S. Vatnitsky, 'A new formalism for reference dosimetry of small and nonstandard fields,' Med. Phys. 35, 5179-5186 (2008)] to the CyberKnife robotic radiosurgery system. Correction factors for intermediate calibration fields, a machine-specific reference field (msr) and two plan-class specific reference fields (pcsr), have been studied. Furthermore, the applicability of the new formalism to clinical dosimetry has been analyzed through the investigation of two clinical treatments. Methods: PTW31014 and Scanditronix-Wellhofer CC13 ionization chamber measurements were performed for the fields under investigation. Absorbed dose to water was determined using alanine reference dosimetry, and experimental correction factors were calculated from alanine to ionization chamber readings ratios. In addition, correction factors were calculated for the intermediate calibration fields and one of the clinical treatment fields using the Monte Carlo method and these were compared with the experimental values. Results: Overall correction factors deviating from unity by approximately 2% were obtained from both measurements and simulations, with values below and above unity for the studied intermediate calibration fields and clinical fields for the ionization chambers under consideration. Monte Carlo simulations yielded correction factors comparable with those obtained from measurements for the machine-specific reference field, although differences from 1% to 3.3% were observed between measured and calculated correction factors for the composite intermediate calibration fields. Dose distribution inhomogeneities are thought to be responsible for such discrepancies. Conclusions: The differences found between overall

  2. Verification of Accuracy of CyberKnife Tumor-tracking Radiation Therapy Using Patient-specific Lung Phantoms

    SciTech Connect

    Jung, Jinhong; Song, Si Yeol; Yoon, Sang Min; Kwak, Jungwon; Yoon, KyoungJun; Choi, Wonsik; Jeong, Seong-Yun; Choi, Eun Kyung; Cho, Byungchul

    2015-07-15

    Purpose: To investigate the accuracy of the CyberKnife Xsight Lung Tracking System (XLTS) compared with that of a fiducial-based target tracking system (FTTS) using patient-specific lung phantoms. Methods and Materials: Three-dimensional printing technology was used to make individualized lung phantoms that closely mimicked the lung anatomy of actual patients. Based on planning computed tomographic data from 6 lung cancer patients who underwent stereotactic ablative radiation therapy using the CyberKnife, the volume above a certain Hounsfield unit (HU) was assigned as the structure to be filled uniformly with polylactic acid material by a 3-dimensional printer (3D Edison, Lokit, Korea). We evaluated the discrepancies between the measured and modeled target positions, representing the total tracking error, using 3 log files that were generated during each treatment for both the FTTS and the XLTS. We also analyzed the γ index between the film dose measured under the FTTS and XLTS. Results: The overall mean values and standard deviations of total tracking errors for the FTTS were 0.36 ± 0.39 mm, 0.15 ± 0.64 mm, and 0.15 ± 0.62 mm for the craniocaudal (CC), left–right (LR), and anteroposterior (AP) components, respectively. Those for the XLTS were 0.38 ± 0.54 mm, 0.13 ± 0.18 mm, and 0.14 ± 0.37 mm for the CC, LR, and AP components, respectively. The average of γ passing rates was 100% for the criteria of 3%, 3 mm; 99.6% for the criteria of 2%, 2 mm; and 86.8% for the criteria of 1%, 1 mm. Conclusions: The XLTS has segmentation accuracy comparable with that of the FTTS and small total tracking errors.

  3. Radiotherapy of Cervical Cancer.

    PubMed

    Vordermark, Dirk

    2016-01-01

    Curative-intent radical radiotherapy of cervical cancer consists of external-beam radiotherapy, brachytherapy, and concomitant chemotherapy with cisplatin. For each element, new developments aim to improve tumor control rates or treatment tolerance. Intensity-modulated radiotherapy (IMRT) has been shown to reduce gastrointestinal toxicity and can be used to selectively increase the radiotherapy dose. Individualized, image-guided brachytherapy enables better adaptation of high-dose volumes to the tumor extension. Intensification of concomitant or sequential systemic therapy is under evaluation. PMID:27614991

  4. Sexual Function After Stereotactic Body Radiotherapy for Prostate Cancer: Results of a Prospective Clinical Trial

    SciTech Connect

    Wiegner, Ellen A.; King, Christopher R.

    2010-10-01

    Purpose: To study the sexual quality of life for prostate cancer patients after stereotactic body radiotherapy (SBRT). Methods and Materials: Using the Expanded Prostate Cancer Index Composite (EPIC)-validated quality-of-life questionnaire, the sexual function of 32 consecutive patients who received prostate SBRT in a prospective Phase II clinical trial were analyzed at baseline, and at median times of 4, 12, 20, and 50 months after treatment. SBRT consisted of 36.25 Gy in five fractions of 7.25 Gy using the Cyberknife. No androgen deprivation therapy was given. The use of erectile dysfunction (ED) medications was monitored. A comprehensive literature review for radiotherapy-alone modalities based on patient self-reported questionnaires served as historical comparison. Results: Median age at treatment was 67.5 years, and median follow-up was 35.5 months (minimum 12 months). The mean EPIC sexual domain summary score, sexual function score, and sexual bother score decreased by 45%, 49%, and 25% respectively at 50 months follow-up. These differences reached clinical relevance by 20 months after treatment. Baseline ED rate was 38% and increased to 71% after treatment (p = 0.024). Use of ED medications was 3% at baseline and progressed to 25%. For patients aged <70 years at follow-up, 60% maintained satisfactory erectile function after treatment compared with only 12% aged {>=}70 years (p = 0.008). Penile bulb dose was not associated with ED. Conclusions: The rates of ED after treatment appear comparable to those reported for other modalities of radiotherapy. Given the modest size of this study and the uncertainties in the physiology of radiotherapy-related ED, these results merit further investigations.

  5. [Radiotherapy of skin cancers].

    PubMed

    Hennequin, C; Rio, E; Mahé, M-A

    2016-09-01

    The indications of radiotherapy for skin cancers are not clearly defined because of the lack of randomised trials or prospective studies. For basal cell carcinomas, radiotherapy frequently offers a good local control, but a randomized trial showed that surgery is more efficient and less toxic. Indications of radiotherapy are contra-indications of surgery for patients older than 60, non-sclerodermiform histology and occurring in non-sensitive areas. Adjuvant radiotherapy could be proposed to squamous cell carcinomas, in case of poor prognostic factors. Dose of 60 to 70Gy are usually required, and must be modulated to the size of the lesions. Adjuvant radiotherapy seems beneficial for desmoplastic melanomas but not for the other histological types. Prophylactic nodal irradiation (45 to 50Gy), for locally advanced tumours (massive nodal involvement), decreases the locoregional failure rate but do not increase survival. Adjuvant radiotherapy (50 to 56Gy) for Merckel cell carcinomas increases also the local control rate, as demonstrated by meta-analysis and a large epidemiological study. Nodal areas must be included, if there is no surgical exploration (sentinel lymph node dissection). Kaposi sarcomas are radiosensitive and could be treated with relatively low doses (24 to 30Gy). Also, cutaneous lymphomas are good indications for radiotherapy: B lymphomas are electively treated with limited fields. The role of total skin electron therapy for T-lymphomas is still discussed; but palliative radiotherapy is very efficient in case of cutaneous nodules. PMID:27522189

  6. Planning National Radiotherapy Services

    PubMed Central

    Rosenblatt, Eduardo

    2014-01-01

    Countries, states, and island nations often need forward planning of their radiotherapy services driven by different motives. Countries without radiotherapy services sponsor patients to receive radiotherapy abroad. They often engage professionals for a feasibility study in order to establish whether it would be more cost-beneficial to establish a radiotherapy facility. Countries where radiotherapy services have developed without any central planning, find themselves in situations where many of the available centers are private and thus inaccessible for a majority of patients with limited resources. Government may decide to plan ahead when a significant exodus of cancer patients travel to another country for treatment, thus exposing the failure of the country to provide this medical service for its citizens. In developed countries, the trigger has been the existence of highly visible waiting lists for radiotherapy revealing a shortage of radiotherapy equipment. This paper suggests that there should be a systematic and comprehensive process of long-term planning of radiotherapy services at the national level, taking into account the regulatory infrastructure for radiation protection, planning of centers, equipment, staff, education programs, quality assurance, and sustainability aspects. Realistic budgetary and cost considerations must also be part of the project proposal or business plan. PMID:25505730

  7. SU-E-T-642: Safety Procedures for Error Elimination in Cyberknife Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiation Therapy (SBRT)

    SciTech Connect

    Hussain, A; Alkafi, A; Al-Najjar, W; Moftah, B

    2014-06-15

    Purpose: Cyberknife system is used for providing stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) hypofractionation scheme. The whole treatment delivery is based on live imaging of the patient. The minor error made at any stage may bring severe radiation injury to the patient or damage to the system itself. Several safety measures were taken to make the system safer. Methods: The radiation treatment provided thru a 6MV linac attached to Kuka robot (Cyberknife G4, Accuray Inc. Sunnyvale, CA, USA). Several possible errors were identified related to patient alignment, treatment planning, dose delivery and physics quality assurance. During dose delivery, manual and visual checks were introduced to confirm pre and intra-treatment imaging to reduce possible errors. One additional step was introduced to confirm that software tracking-tools had worked correctly with highest possible confidence level. Robotic head move in different orientations over and around the patient body, the rigidity of linac-head cover and other accessories was checked periodically. The vender was alerted when a tiny or bigger piece of equipment needed additional interlocked support. Results: As of our experience treating 525 patients on Cyberknife during the last four years, we saw on and off technical issues. During image acquisition, it was made essential to follow the site-specific imaging protocols. Adequate anatomy was contoured to document the respective doses. Followed by auto-segmentation, manual tweaking was performed on every structure. The calculation box was enclosing the whole image during the final calculation. Every plan was evaluated on slice-by slice basis. To review the whole process, a check list was maintained during the physics 2nd-check. Conclusion: The implementation of manual and visual additional checks introduced along with automated checks for confirmation was found promising in terms of reduction in systematic errors and making the system

  8. A phantom study to determine the optimum size of a single collimator for shortening the treatment time in CyberKnife stereotactic radiosurgery of spherical targets.

    PubMed

    Harikrishnaperumal, Sudahar; Kurup, Gopalakrishna; Venkatraman, Murali; Jagadeesan, Velmurugan

    2012-01-01

    Prolonged treatment execution time is a concern in CyberKnife robotic radiosurgery. Beam reduction and node reduction technique, and monitor unit optimization methods are adopted to reduce the treatment time. Usage of single collimator in the CyberKnife treatment plan can potentially reduce collimator exchange time. An optimal single collimator, which yields an acceptable dose distribution along with minimum number of nodes, beams, and monitor units, can be a versatile alternative for shortening treatment time. The aim of the present study is to find the optimal single collimator in CyberKnife treatment planning to shorten the treatment time with the acceptable dose distribution. A spherical planning target volume PTV1 was drawn in an anthropomorphic head and neck phantom. Plans with same treatment goals were generated for all the 12 collimators independently. D(95%) was selected as the prescribing isodose and the prescribed dose was 10 Gy. The plan of the optimal collimator size was evaluated for conformity, homogeneity, and dose spillage outside the target. The optimum collimator size and the target dimensions were correlated. The study was repeated with two other target volumes PTV2 and PTV3 for generalizing the results. Collimator sizes just above the diameter of the spherical PTVs were yielding least number of nodes and beams with acceptable dose distributions. The collimator size of 35 mm is optimum for the PTV1, whose diameter is 31.4 mm. Similarly, 50 mm collimator is optimum for PTV2 (diameter= 45.2 mm) and 20 mm collimator is optimum for PTV3 (Diameter = 17.3 mm). The total number of monitor units is found to reduce with increasing collimator size. Optimal single collimator is found to be useful for shortening the treatment time in spherical targets. Studies on two clinical targets, (a brain metastasis and a liver metastasis cases) show comparable results with the phantom study. PMID:22955653

  9. SU-E-T-85: Comparison of Treatment Plans Calculated Using Ray Tracing and Monte Carlo Algorithms for Lung Cancer Patients Having Undergone Radiotherapy with Cyberknife

    SciTech Connect

    Pennington, A; Selvaraj, R; Kirkpatrick, S; Oliveira, S; Leventouri, T

    2014-06-01

    Purpose: The latest publications indicate that the Ray Tracing algorithm significantly overestimates the dose delivered as compared to the Monte Carlo (MC) algorithm. The purpose of this study is to quantify this overestimation and to identify significant correlations between the RT and MC calculated dose distributions. Methods: Preliminary results are based on 50 preexisting RT algorithm dose optimization and calculation treatment plans prepared on the Multiplan treatment planning system (Accuray Inc., Sunnyvale, CA). The analysis will be expanded to include 100 plans. These plans are recalculated using the MC algorithm, with high resolution and 1% uncertainty. The geometry and number of beams for a given plan, as well as the number of monitor units, is constant for the calculations for both algorithms and normalized differences are compared. Results: MC calculated doses were significantly smaller than RT doses. The D95 of the PTV was 27% lower for the MC calculation. The GTV and PTV mean coverage were 13 and 39% less for MC calculation. The first parameter of conformality, as defined as the ratio of the Prescription Isodose Volume to the PTV Volume was on average 1.18 for RT and 0.62 for MC. Maximum doses delivered to OARs was reduced in the MC plans. The doses for 1000 and 1500 cc of total lung minus PTV, respectively were reduced by 39% and 53% for the MC plans. The correlation of the ratio of air in PTV to the PTV with the difference in PTV coverage had a coefficient of −0.54. Conclusion: The preliminary results confirm that the RT algorithm significantly overestimates the dosages delivered confirming previous analyses. Finally, subdividing the data into different size regimes increased the correlation for the smaller size PTVs indicating the MC algorithm improvement verses the RT algorithm is dependent upon the size of the PTV.

  10. The Continuous Assessment of Cranial Motion in Thermoplastic Masks During CyberKnife Radiosurgery for Trigeminal Neuralgia

    PubMed Central

    Mayville, Alan

    2016-01-01

    Stereotactic radiosurgery (SRS) treatment is characterized by high doses per fraction and extremely steep dose gradients. This requires a great degree of accurate localization to the appropriate treatment position, and continuous immobilization during the treatment session. In the case of Trigeminal Neuralgia (TGN) treatment this is especially true as the very small target volume makes positional accuracy critical. In this study we carried out a quantitative analysis of patient motion during the full treatment fraction within a radiosurgery immobilization mask system. Patient cranial movement was assessed by using the image guidance stereo x-ray cameras on a CyberKnife (CK) M6 robotic radiosurgery system (Accuray, Sunnyvale, CA). A total of five patients received treatments for either right or left TGN. The duration of treatment varied from 24-64 minutes. Orthogonal images were taken every 15 seconds during the treatment to assess patient movement. Approximately 60 stereo images were taken per patient and a total of 560 images were analyzed in this study. The mean absolute movement in each of longitudinal, lateral or vertical directions was approximately 0.3 mm for the duration of the treatment; however, on occasion much greater movement was observed during a fraction. The maximum displacement was in the longitudinal direction and reached 2.4 mm compared to the initial setup. Images taken at the end of the treatment session showed that the patients typically return to a position closer to the original setup position than the maximum excursion that occurred. This data suggests that although this mask system appears stable during much of the treatment session; for some patients there may be momentary patient movements that take place. Frequent imaging and correction can help mitigate the effect of this movement. It is important to understand the limitations of non-invasive mask systems when used for very high precision treatment. PMID:27330875

  11. Clinical outcome of fiducial-less CyberKnife radiosurgery for stage I non-small cell lung cancer

    PubMed Central

    Jung, In-Hye; Jung, Jinhong; Cho, Byungchul; Kwak, Jungwon; Je, Hyoung Uk; Choi, Wonsik; Jung, Nuri Hyun; Kim, Su Ssan; Choi, Eun Kyung

    2015-01-01

    Purpose To evaluate the treatment results in early stage non-small cell lung cancer patients who have undergone fiducial-less CyberKnife radiosurgery (CKRS). Materials and Methods From June 2011 to November 2013, 58 patients underwent CKRS at Asan Medical Center for stage I lung cancer. After excluding 14 patients, we retrospectively reviewed the records of the remaining 44 patients. All analyses were performed using SPSS ver. 21. Results The median age at diagnosis was 75 years. Most patients had inoperable primary lung cancer with a poor pulmonary function test with comorbidity or old age. The clinical stage was IA in 30 patients (68.2%), IB in 14 (31.8%). The mean tumor size was 2.6 cm (range, 1.2 to 4.8 cm), and the tumor was smaller than 2 cm in 12 patients (27.3%). The radiation dose given was 48-60 Gy in 3-4 fractions. In a median follow-up of 23.1 months, local recurrence occurred in three patients (2-year local recurrence-free survival rate, 90.4%) and distant metastasis occurred in 13 patients. All patients tolerated the radiosurgery well, only two patients developing grade 3 dyspnea. The most common complications were radiation-induced fibrosis and pneumonitis. Eight patients died due to cancer progression. Conclusion The results showed that fiducial-less CKRS shows comparable local tumor control and survival rates to those of LINAC-based SABR or CKRS with a fiducial marker. Thus, fiducial-less CKRS using Xsight lung tracking system can be effectively and safely performed for patients with medically inoperable stage I non-small cell lung cancer without any risk of procedure-related complication. PMID:26157678

  12. The Continuous Assessment of Cranial Motion in Thermoplastic Masks During CyberKnife Radiosurgery for Trigeminal Neuralgia.

    PubMed

    Bichay, Tewfik J; Mayville, Alan

    2016-01-01

    Stereotactic radiosurgery (SRS) treatment is characterized by high doses per fraction and extremely steep dose gradients. This requires a great degree of accurate localization to the appropriate treatment position, and continuous immobilization during the treatment session. In the case of Trigeminal Neuralgia (TGN) treatment this is especially true as the very small target volume makes positional accuracy critical. In this study we carried out a quantitative analysis of patient motion during the full treatment fraction within a radiosurgery immobilization mask system. Patient cranial movement was assessed by using the image guidance stereo x-ray cameras on a CyberKnife (CK) M6 robotic radiosurgery system (Accuray, Sunnyvale, CA). A total of five patients received treatments for either right or left TGN. The duration of treatment varied from 24-64 minutes. Orthogonal images were taken every 15 seconds during the treatment to assess patient movement. Approximately 60 stereo images were taken per patient and a total of 560 images were analyzed in this study. The mean absolute movement in each of longitudinal, lateral or vertical directions was approximately 0.3 mm for the duration of the treatment; however, on occasion much greater movement was observed during a fraction. The maximum displacement was in the longitudinal direction and reached 2.4 mm compared to the initial setup. Images taken at the end of the treatment session showed that the patients typically return to a position closer to the original setup position than the maximum excursion that occurred. This data suggests that although this mask system appears stable during much of the treatment session; for some patients there may be momentary patient movements that take place. Frequent imaging and correction can help mitigate the effect of this movement. It is important to understand the limitations of non-invasive mask systems when used for very high precision treatment. PMID:27330875

  13. Direct plan comparison of RapidArc and CyberKnife for spine stereotactic body radiation therapy

    NASA Astrophysics Data System (ADS)

    Choi, Young Eun; Kwak, Jungwon; Song, Si Yeol; Choi, Eun Kyung; Ahn, Seung Do; Cho, Byungchul

    2015-07-01

    We compared the treatment planning performance of RapidArc (RA) vs. CyberKnife (CK) for spinal stereotactic body radiation therapy (SBRT). Ten patients with spinal lesions who had been treated with CK were re-planned with RA, which consisted of two complete arcs. Computed tomography (CT) and volumetric dose data of CK, generated using the Multiplan (Accuray) treatment planning system (TPS) and the Ray-trace algorithm, were imported to Varian Eclipse TPS in Dicom format, and the data were compared with the RA plan by using an analytical anisotropic algorithm (AAA) dose calculation. The optimized dose priorities for both the CK and the RA plans were similar for all patients. The highest priority was to provide enough dose coverage to the planned target volume (PTV) while limiting the maximum dose to the spinal cord. Plan quality was evaluated with respect to PTV coverage, conformity index (CI), high-dose spillage, intermediate-dose spillage (R50% and D2cm), and maximum dose to the spinal cord, which are criteria recommended by the RTOG 0631 spine and 0915 lung SBRT protocols. The mean CI' SD values of the PTV were 1.11' 0.03 and 1.17' 0.10 for RA and CK ( p = 0.02), respectively. On average, the maximum dose delivered to the spinal cord in CK plans was approximately 11.6% higher than that in RA plans, and this difference was statistically significant ( p < 0.001). High-dose spillages were 0.86% and 2.26% for RA and CK ( p = 0.203), respectively. Intermediate-dose spillage characterized by D2cm was lower for RA than for CK; however, R50% was not statistically different. Even though both systems can create highly conformal volumetric dose distributions, the current study shows that RA demonstrates lower high- and intermediate-dose spillages than CK. Therefore, RA plans for spinal SBRT may be superior to CK plans.

  14. Clinical Accuracy of the Respiratory Tumor Tracking System of the CyberKnife: Assessment by Analysis of Log Files

    SciTech Connect

    Hoogeman, Mischa Prevost, Jean-Briac; Nuyttens, Joost; Poell, Johan; Levendag, Peter; Heijmen, Ben

    2009-05-01

    Purpose: To quantify the clinical accuracy of the respiratory motion tracking system of the CyberKnife treatment device. Methods and Materials: Data in log files of 44 lung cancer patients treated with tumor tracking were analyzed. Errors in the correlation model, which relates the internal target motion with the external breathing motion, were quantified. The correlation model error was compared with the geometric error obtained when no respiratory tracking was used. Errors in the prediction method were calculated by subtracting the predicted position from the actual measured position after 192.5 ms (the time lag to prediction in our current system). The prediction error was also measured for a time lag of 115 ms and a new prediction method. Results: The mean correlation model errors were less than 0.3 mm. Standard deviations describing intrafraction variations around the whole-fraction mean error were 0.2 to 1.9 mm for cranio-caudal, 0.1 to 1.9 mm for left-right, and 0.2 to 2.5 mm for anterior-posterior directions. Without the use of respiratory tracking, these variations would have been 0.2 to 8.1 mm, 0.2 to 5.5 mm, and 0.2 to 4.4 mm. The overall mean prediction error was small (0.0 {+-} 0.0 mm) for all directions. The intrafraction standard deviation ranged from 0.0 to 2.9 mm for a time delay of 192.5 ms but was halved by using the new prediction method. Conclusions: Analyses of the log files of real clinical cases have shown that the geometric error caused by respiratory motion is substantially reduced by the application of respiratory motion tracking.

  15. Recruitment in Radiotherapy

    ERIC Educational Resources Information Center

    Deeley, T. J.; And Others

    1976-01-01

    The Faculty Board of Radiotherapy and Oncology of the Royal College of Radiobiologists surveyed the factors thought to influence recruitment into the specialty. Possible factors listed in replies of 36 questionnaires are offered. (LBH)

  16. Development of a Synthetic Adaptive Neuro-Fuzzy Prediction Model for Tumor Motion Tracking in External Radiotherapy by Evaluating Various Data Clustering Algorithms.

    PubMed

    Ghorbanzadeh, Leila; Torshabi, Ahmad Esmaili; Nabipour, Jamshid Soltani; Arbatan, Moslem Ahmadi

    2016-04-01

    In image guided radiotherapy, in order to reach a prescribed uniform dose in dynamic tumors at thorax region while minimizing the amount of additional dose received by the surrounding healthy tissues, tumor motion must be tracked in real-time. Several correlation models have been proposed in recent years to provide tumor position information as a function of time in radiotherapy with external surrogates. However, developing an accurate correlation model is still a challenge. In this study, we proposed an adaptive neuro-fuzzy based correlation model that employs several data clustering algorithms for antecedent parameters construction to avoid over-fitting and to achieve an appropriate performance in tumor motion tracking compared with the conventional models. To begin, a comparative assessment is done between seven nuero-fuzzy correlation models each constructed using a unique data clustering algorithm. Then, each of the constructed models are combined within an adaptive sevenfold synthetic model since our tumor motion database has high degrees of variability and that each model has its intrinsic properties at motion tracking. In the proposed sevenfold synthetic model, best model is selected adaptively at pre-treatment. The model also updates the steps for each patient using an automatic model selectivity subroutine. We tested the efficacy of the proposed synthetic model on twenty patients (divided equally into two control and worst groups) treated with CyberKnife synchrony system. Compared to Cyberknife model, the proposed synthetic model resulted in 61.2% and 49.3% reduction in tumor tracking error in worst and control group, respectively. These results suggest that the proposed model selection program in our synthetic neuro-fuzzy model can significantly reduce tumor tracking errors. Numerical assessments confirmed that the proposed synthetic model is able to track tumor motion in real time with high accuracy during treatment. PMID:25765021

  17. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    SciTech Connect

    Stiebel-Kalish, Hadas; Reich, Ehud; Gal, Lior; Rappaport, Zvi Harry; Nissim, Ouzi; Pfeffer, Raphael; Spiegelmann, Roberto

    2012-02-01

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  18. [Radiotherapy of larynx cancers].

    PubMed

    Pointreau, Y; Lafond, C; Legouté, F; Trémolières, P; Servagi-Vernat, S; Giraud, P; Maingon, P; Calais, G; Lapeyre, M

    2016-09-01

    Intensity-modulated radiotherapy is the gold standard in the treatment of larynx cancers (except T1 glottic tumour). Early T1 and T2 tumours may be treated by exclusive radiation or surgery. For tumours requiring total laryngectomy (T2 or T3), induction chemotherapy followed by exclusive radiotherapy or concurrent chemoradiotherapy is possible. For T4 tumour, surgery must be proposed. The treatment of lymph nodes is based on the initial treatment of the primary tumour. In non-surgical procedure, in case of sequential radiotherapy, the curative dose is 70Gy and the prophylactic dose is 50Gy. An integrated simultaneous boost radiotherapy is allowed (70Gy in 2Gy per fraction and 56Gy in 1.8Gy per fraction or 70Gy in 2.12Gy per fraction). Postoperatively, radiotherapy is used in locally advanced cancer with dose levels based on pathologic criteria (66Gy for R1 resection, 50 to 54Gy for complete resection). Volume delineation was based on guidelines. PMID:27521037

  19. SU-E-T-224: Is Monte Carlo Dose Calculation Method Necessary for Cyberknife Brain Treatment Planning?

    SciTech Connect

    Wang, L; Fourkal, E; Hayes, S; Jin, L; Ma, C

    2014-06-01

    Purpose: To study the dosimetric difference resulted in using the pencil beam algorithm instead of Monte Carlo (MC) methods for tumors adjacent to the skull. Methods: We retrospectively calculated the dosimetric differences between RT and MC algorithms for brain tumors treated with CyberKnife located adjacent to the skull for 18 patients (total of 27 tumors). The median tumor sizes was 0.53-cc (range 0.018-cc to 26.2-cc). The absolute mean distance from the tumor to the skull was 2.11 mm (range - 17.0 mm to 9.2 mm). The dosimetric variables examined include the mean, maximum, and minimum doses to the target, the target coverage (TC) and conformality index. The MC calculation used the same MUs as the RT dose calculation without further normalization and 1% statistical uncertainty. The differences were analyzed by tumor size and distance from the skull. Results: The TC was generally reduced with the MC calculation (24 out of 27 cases). The average difference in TC between RT and MC was 3.3% (range 0.0% to 23.5%). When the TC was deemed unacceptable, the plans were re-normalized in order to increase the TC to 99%. This resulted in a 6.9% maximum change in the prescription isodose line. The maximum changes in the mean, maximum, and minimum doses were 5.4 %, 7.7%, and 8.4%, respectively, before re-normalization. When the TC was analyzed with regards to target size, it was found that the worst coverage occurred with the smaller targets (0.018-cc). When the TC was analyzed with regards to the distance to the skull, there was no correlation between proximity to the skull and TC between the RT and MC plans. Conclusions: For smaller targets (< 4.0-cc), MC should be used to re-evaluate the dose coverage after RT is used for the initial dose calculation in order to ensure target coverage.

  20. [Prostate cancer external beam radiotherapy].

    PubMed

    de Crevoisier, R; Pommier, P; Latorzeff, I; Chapet, O; Chauvet, B; Hennequin, C

    2016-09-01

    The prostate external beam radiotherapy techniques are described, when irradiating the prostate or after prostatectomy, with and without pelvic lymph nodes. The following parts are presented: indications of radiotherapy, total dose and fractionation, planning CT image acquisition, volume of interest delineation (target volumes and organs at risk) and margins, Intensity modulated radiotherapy planning and corresponding dose-volume constraints, and finally Image guided radiotherapy. PMID:27516051

  1. Radiotherapy of inoperable lung cancer

    SciTech Connect

    Namer, M.; Lalanne, C.M.; Boublil, J.L.; Hery, M.; Chauvel, P.; Verschoore, J.; Aubanel, J.M.; Bruneton, J.N.

    1980-08-01

    Evaluation of loco-regional results obtained by radiotherapy for 31 patients with inoperable epidermoid lung cancer revealed objective remission (over 50%) in only 25% of patients. These results emphasize the limited effectiveness of radiotherapy in such cases and point out the need for increased research in radiotherapy techniques if survival rates are to be improved.

  2. [Radiotherapy for brain metastases].

    PubMed

    Latorzeff, I; Antoni, D; Gaudaire-Josset, S; Feuvret, L; Tallet-Richard, A; Truc, G; Noël, G

    2016-09-01

    Radiotherapy for brain metastases has become more multifaceted. Indeed, with the improvement of the patient's life expectancy, side effects must be undeniably avoided and the retreatments or multiple treatments are common. The cognitive side effects should be warned and the most modern techniques of radiation therapy are used regularly to reach this goal. The new classifications of patients with brain metastases help guiding treatment more appropriately. Stereotactic radiotherapy has supplanted whole brain radiation therapy both for patients with metastases in place and for those who underwent surgery. Hippocampus protection is possible with intensity-modulated radiotherapy. Its relevance in terms of cognitive functioning should be more clearly demonstrated but the requirement, for using it, is increasingly strong. While addressing patients in palliative phase, the treatment of brain metastases is one of the localisations where technical thinking is the most challenging. PMID:27523410

  3. [Radiotherapy in Europe].

    PubMed

    Verheij, M; Slotman, B J

    2016-01-01

    Radiotherapy plays an important part in the curing of cancer patients and is an effective treatment for tumour-related symptoms. However, in many countries the level of access to this treatment modality is unacceptably low due to shortage of infrastructure, modern apparatus and trained staff. In Europe it is mainly the Eastern European countries that are behind in the provision of and accessibility to radiotherapy. Worldwide investment to narrow the gap would put an end to these undesirable differences. In addition, these investments would deliver economic benefits, especially in low-to-middle income countries. In this article, on the basis of a number of recently published reports, we discuss the differences that exist in the geographical spread of radiotherapy departments and the availability of apparatus within Europe. In conclusion we also take a short look at the Dutch situation. PMID:27334085

  4. A Retrospective Comparison of Robotic Stereotactic Body Radiotherapy and Three-Dimensional Conformal Radiotherapy for the Reirradiation of Locally Recurrent Nasopharyngeal Carcinoma

    SciTech Connect

    Ozyigit, Gokhan; Cengiz, Mustafa; Yazici, Gozde; Yildiz, Ferah; Gurkaynak, Murat; Zorlu, Faruk; Yildiz, Demet; Hosal, Sefik; Gullu, Ibrahim; Akyol, Fadil

    2011-11-15

    Purpose: We assessed therapeutic outcomes of reirradiation with robotic stereotactic radiotherapy (SBRT) for locally recurrent nasopharyngeal carcinoma (LRNPC) patients and compared those results with three-dimensional conformal radiotherapy (CRT) with or without brachytherapy (BRT). Methods and Materials: Treatment outcomes were evaluated retrospectively in 51 LRNPC patients receiving either robotic SBRT (24 patients) or CRT with or without BRT (27 patients) in our department. CRT was delivered with a 6-MV linear accelerator, and a median total reirradiation dose of 57 Gy in 2 Gy/day was given. Robotic SBRT was delivered with CyberKnife (Accuray, Sunnyvale, CA). Patients in the SBRT arm received 30 Gy over 5 consecutive days. We calculated actuarial local control and cancer-specific survival rates for the comparison of treatment outcomes in SBRT and CRT arms. The Common Terminology Criteria for Adverse Events v3.0 was used for toxicity evaluation. Results: The median follow-up was 24 months for all patients. Two-year actuarial local control rates were 82% and 80% for SBRT and CRT arms, respectively (p = 0.6). Two-year cancer-specific survival rates were 64% and 47% for the SBRT and CRT arms, respectively (p = 0.4). Serious late toxicities (Grade 3 and above) were observed in 21% of patients in the SBRT arm, whereas 48% of patients had serious toxicity in the CRT arm (p = 0.04). Fatal complications occurred in three patients (12.5%) of the SBRT arm, and four patients (14.8%) of the CRT arm (p = 0.8). T stage at recurrence was the only independent predictor for local control and survival. Conclusion: Our robotic SBRT protocol seems to be feasible and less toxic in terms of late effects compared with CRT arm for the reirradiation of LRNPC patients.

  5. SU-E-J-06: Additional Imaging Guidance Dose to Patient Organs Resulting From X-Ray Tubes Used in CyberKnife Image Guidance System

    SciTech Connect

    Sullivan, A; Ding, G

    2015-06-15

    Purpose: The use of image-guided radiation therapy (IGRT) has become increasingly common, but the additional radiation exposure resulting from repeated image guidance procedures raises concerns. Although there are many studies reporting imaging dose from different image guidance devices, imaging dose for the CyberKnife Robotic Radiosurgery System is not available. This study provides estimated organ doses resulting from image guidance procedures on the CyberKnife system. Methods: Commercially available Monte Carlo software, PCXMC, was used to calculate average organ doses resulting from x-ray tubes used in the CyberKnife system. There are seven imaging protocols with kVp ranging from 60 – 120 kV and 15 mAs for treatment sites in the Cranium, Head and Neck, Thorax, and Abdomen. The output of each image protocol was measured at treatment isocenter. For each site and protocol, Adult body sizes ranging from anorexic to extremely obese were simulated since organ dose depends on patient size. Doses for all organs within the imaging field-of-view of each site were calculated for a single image acquisition from both of the orthogonal x-ray tubes. Results: Average organ doses were <1.0 mGy for every treatment site and imaging protocol. For a given organ, dose increases as kV increases or body size decreases. Higher doses are typically reported for skeletal components, such as the skull, ribs, or clavicles, than for softtissue organs. Typical organ doses due to a single exposure are estimated as 0.23 mGy to the brain, 0.29 mGy to the heart, 0.08 mGy to the kidneys, etc., depending on the imaging protocol and site. Conclusion: The organ doses vary with treatment site, imaging protocol and patient size. Although the organ dose from a single image acquisition resulting from two orthogonal beams is generally insignificant, the sum of repeated image acquisitions (>100) could reach 10–20 cGy for a typical treatment fraction.

  6. Radiotherapy for craniopharyngioma.

    PubMed

    Aggarwal, Ajay; Fersht, Naomi; Brada, Michael

    2013-03-01

    Radiotherapy remains the mainstay of multidisciplinary management of patients with incompletely resected and recurrent craniopharyngioma. Advances in imaging and radiotherapy technology offer new alternatives with the principal aim of improving the accuracy of treatment and reducing the volume of normal brain receiving significant radiation doses. We review the available technologies, their technical advantages and disadvantages and the published clinical results. Fractionated high precision conformal radiotherapy with image guidance remains the gold standard; the results of single fraction treatment are disappointing and hypofractionation should be used with caution as long term results are not available. There is insufficient data on the use of protons to assess the comparative efficacy and toxicity. The precision of treatment delivery needs to be coupled with experienced infrastructure and more intensive quality assurance to ensure best treatment outcome and this should be carried out within multidisciplinary teams experienced in the management of craniopharyngioma. The advantages of the combined skills and expertise of the team members may outweigh the largely undefined clinical gain from novel radiotherapy technologies.

  7. [Radiotherapy of cerebral metastases].

    PubMed

    Soffietti, R

    1984-05-31

    Radiotherapy of brain metastases is almost always palliative, as histologically documented cures are exceptional. Radiotherapy alone improves neurological symptoms in two-thirds of cases, but median survivals do not generally exceed 6 months. Whole brain radiation is mandatory as the lesions are often multiple, even when they escape clinical demonstration. There is no definite difference in prognosis after conventional rather than concentrated treatments. The role of steroids in the prevention and/or control of the acute effects of radiotherapy is controversial. Favorable prognostic factors are a good neurological and performance status, a solitary brain metastasis of a primary tumor under control, some histological types (i.e.: metastases from "oat" cell carcinomas, breast carcinomas, non-Hodgkin lymphomas are more responsive). Surgical excision before radiotherapy improves survival (6-12 months), especially in solitary metastases from melanomas, colon and renal tumors. Reirradiation can be useful, but the risk of delayed damage to the normal tissue in patients with longer survival (solitary operated and irradiated metastases) must be considered. The search for new radiotherapeutic modalities must be based on a deeper understanding of the biological factors involved in the response to radiation through controlled anatomo-clinical studies and biological research on experimental models.

  8. [Radiotherapy of lymphomas].

    PubMed

    Barillot, I; Mahé, M A; Antoni, D; Hennequin, C

    2016-09-01

    Radiotherapy for Hodgkin's lymphoma has evolved over time but retains a dominant position in the treatment of early stage tumours. Its indications are more limited for non-Hodgkin's lymphomas, but the techniques follow the same principles whatever the histological type. This review presents the French recommendations in terms of preparation and choice of irradiation techniques. PMID:27521031

  9. Dosimetric comparison between cone/Iris-based and InCise MLC-based CyberKnife plans for single and multiple brain metastases.

    PubMed

    Jang, Si Young; Lalonde, Ron; Ozhasoglu, Cihat; Burton, Steven; Heron, Dwight; Huq, M Saiful

    2016-01-01

    We performed an evaluation of the CyberKnife InCise MLC by comparing plan qualities for single and multiple brain lesions generated using the first version of InCise MLC, fixed cone, and Iris collimators. We also investigated differences in delivery efficiency among the three collimators. Twenty-four patients with single or multiple brain mets treated previously in our clinic on a CyberKnife M6 using cone/Iris collimators were selected for this study. Treatment plans were generated for all lesions using the InCise MLC. Number of monitor units, delivery time, target coverage, conformity index, and dose falloff were compared between MLC- and clinical cone/Iris-based plans. Statistical analysis was performed using the non-parametric Wilcoxon-Mann-Whitney signed-rank test. The planning accuracy of the MLC-based plans was validated using chamber and film measurements. The InCise MLC-based plans achieved mean dose and target coverage comparable to the cone/Iris-based plans. Although the conformity indices of the MLC-based plans were slightly higher than those of the cone/Iris-based plans, beam delivery time for the MLC-based plans was shorter by 30% ~ 40%. For smaller targets or cases with OARs located close to or abutting target volumes, MLC-based plans provided inferior dose conformity compared to cone/Iris-based plans. The QA results of MLC-based plans were within 5% absolute dose difference with over 90% gamma passing rate using 2%/2 mm gamma criteria. The first version of InCise MLC could be a useful delivery modality, especially for clinical situations for which delivery time is a limiting factor or for multitarget cases. PMID:27685124

  10. [Radiotherapy of breast cancer].

    PubMed

    Hennequin, C; Barillot, I; Azria, D; Belkacémi, Y; Bollet, M; Chauvet, B; Cowen, D; Cutuli, B; Fourquet, A; Hannoun-Lévi, J M; Leblanc, M; Mahé, M A

    2016-09-01

    In breast cancer, radiotherapy is an essential component of the treatment. After conservative surgery for an infiltrating carcinoma, radiotherapy must be systematically performed, regardless of the characteristics of the disease, because it decreases the rate of local recurrence and by this way, specific mortality. Partial breast irradiation could not be proposed routinely but only in very selected and informed patients. For ductal carcinoma in situ, adjuvant radiotherapy must be also systematically performed after lumpectomy. After mastectomy, chest wall irradiation is required for pT3-T4 tumours and if there is an axillary nodal involvement, whatever the number of involved lymph nodes. After neo-adjuvant chemotherapy and mastectomy, in case of pN0 disease, chest wall irradiation is recommended if there is a clinically or radiologically T3-T4 or node positive disease before chemotherapy. Axillary irradiation is recommended only if there is no axillary surgical dissection and a positive sentinel lymph node. Supra and infra-clavicular irradiation is advised in case of positive axillary nodes. Internal mammary irradiation must be discussed case by case, according to the benefit/risk ratio (cardiac toxicity). Dose to the chest wall or the breast must be between 45-50Gy with a conventional fractionation. A boost dose over the tumour bed is required if the patient is younger than 60 years old. Hypofractionation (42.5 Gy in 16 fractions, or 41.6 Gy en 13 or 40 Gy en 15) is possible after tumorectomy and if a nodal irradiation is not mandatory. Delineation of the breast, the chest wall and the nodal areas are based on clinical and radiological evaluations. 3D-conformal irradiation is the recommended technique, intensity-modulated radiotherapy must be proposed only in case of specific clinical situations. Respiratory gating could be useful to decrease the cardiac dose. Concomitant administration of chemotherapy in unadvised, but hormonal treatment could be start with

  11. Efficacy of stereotactic body radiotherapy for hepatocellular carcinoma with portal vein tumor thrombosis/inferior vena cava tumor thrombosis: evaluation by comparison with conventional three-dimensional conformal radiotherapy

    PubMed Central

    Matsuo, Yoshiro; Yoshida, Kenji; Nishimura, Hideki; Ejima, Yasuo; Miyawaki, Daisuke; Uezono, Haruka; Ishihara, Takeaki; Mayahara, Hiroshi; Fukumoto, Takumi; Ku, Yonson; Yamaguchi, Masato; Sugimoto, Koji; Sasaki, Ryohei

    2016-01-01

    This study aimed to evaluate the efficacy of stereotactic body radiotherapy (SBRT) compared with three-dimensional conformal radiotherapy (3DCRT). Forty-three patients with portal vein tumor thrombosis (PVTT)/inferior vena cava tumor thrombosis (IVCTT) treated with SBRT (27 with CyberKnife (CK) and 16 with TrueBeam (TB)) from April 2013 to December 2014, and 54 treated with 3DCRT from June 2008 to March 2013 were evaluated. Dosimetric parameters, response to radiotherapy (RT) and survival outcomes were compared in total SBRT vs. 3DCRT, CK vs. 3DCRT and TB vs. 3DCRT, respectively. The median biologically effective dose 10 (BED10) values in total SBRT, CK, TB and 3DCRT were 73.4 Gy10, 75.0 Gy10, 60.5 Gy10 and 58.5 Gy10, respectively (P < 0.001 in total SBRT vs. 3DCRT, P < 0.001 in CK vs. 3DCRT, P = 0.004 in TB vs. 3DCRT). The tumor response rates were 67%, 70%, 62% and 46%, respectively (P = 0.04, P = 0.04, P = 0.25). The 1-year overall survival rates were 49.3%, 56.7%, 38.1% and 29.3%, respectively (P = 0.02, P = 0.02, P = 0.30), and the 1-year local progression rates were 20.4%, 21.9%, 18.8% and 43.6%, respectively (P = 0.01, P = 0.04, P = 0.10). The use of SBRT made it possible to achieve a higher BED10 compared with the use of 3DCRT. Improvements in local control and survival were achieved in the CK group and the total SBRT group. Our results suggest that SBRT may have the potential to be the standard RT technique for the treatment of PVTT/IVCTT. PMID:27053259

  12. Radiotherapy of early glottic cancer.

    PubMed

    Harwood, A R; Hawkins, N V; Keane, T; Cummings, B; Beale, F A; Rider, W D; Bryce, D P

    1980-03-01

    Patients (383) with stage Tis, Tla and Tlb NoMo glottic cancer are reviewed. Radiotherapy cured 93% of Tis patients and 86% of Tla and Tlb cases. Of all recurrences, 63% were cured. No patient with stage Tis died as a result of tumor and only 5% of stage Tla and Tlb died from tumor. Involvement of the anterior commissure or both vocal cords did not influence control rates by radiotherapy. Mobility of the vocal cord and size of radiotherapy field were significant factors influencing control by radiotherapy. Late recurrences and/or second primaries in the larynx following radiotherapy are rare. Second primaries in the respiratory tract (especially lung) are common and are as important a cause of death as laryngeal cancer in T1 cases. It is concluded that moderate dose radiotherapy with surgery for salvage is a highly effective method of management for early glottic cancer. PMID:7359967

  13. Long-Term Outcomes From a Prospective Trial of Stereotactic Body Radiotherapy for Low-Risk Prostate Cancer

    SciTech Connect

    King, Christopher R.; Brooks, James D.; Gill, Harcharan; Presti, Joseph C.

    2012-02-01

    Purpose: Hypofractionated radiotherapy has an intrinsically different normal tissue and tumor radiobiology. The results of a prospective trial of stereotactic body radiotherapy (SBRT) for prostate cancer with long-term patient-reported toxicity and tumor control rates are presented. Methods and Materials: From 2003 through 2009, 67 patients with clinically localized low-risk prostate cancer were enrolled. Treatment consisted of 36.25 Gy in 5 fractions using SBRT with the CyberKnife as the delivery technology. No patient received hormone therapy. Patient self-reported bladder and rectal toxicities were graded on the Radiation Therapy Oncology Group scale (RTOG). Results: Median follow-up was 2.7 years. There were no grade 4 toxicities. Radiation Therapy Oncology Group Grade 3, 2, and 1 bladder toxicities were seen in 3% (2 patients), 5% (3 patients), and 23% (13 patients) respectively. Dysuria exacerbated by urologic instrumentation accounted for both patients with Grade 3 toxicity. Urinary incontinence, complete obstruction, or persistent hematuria was not observed. Rectal Grade 3, 2, and 1 toxicities were seen in 0, 2% (1 patient), and 12.5% (7 patients), respectively. Persistent rectal bleeding was not observed. Low-grade toxicities were substantially less frequent with QOD vs. QD dose regimen (p = 0.001 for gastrointestinal and p = 0.007 for genitourinary). There were two prostate-specific antigen (PSA), biopsy-proven failures with negative metastatic workup. Median PSA at follow-up was 0.5 {+-} 0.72 ng/mL. The 4-year Kaplan-Meier PSA relapse-free survival was 94% (95% confidence interval, 85%-102%). Conclusion: Significant late bladder and rectal toxicities from SBRT for prostate cancer are infrequent. PSA relapse-free survival compares favorably with other definitive treatments. The current evidence supports consideration of stereotactic body radiotherapy among the therapeutic options for localized prostate cancer.

  14. Risk-adaptive radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Yusung

    Currently, there is great interest in integrating biological information into intensity-modulated radiotherapy (IMRT) treatment planning with the aim of boosting high-risk tumor subvolumes. Selective boosting of tumor subvolumes can be accomplished without violating normal tissue complication constraints using information from functional imaging. In this work we have developed a risk-adaptive optimization-framework that utilizes a nonlinear biological objective function. Employing risk-adaptive radiotherapy for prostate cancer, it is possible to increase the equivalent uniform dose (EUD) by up to 35.4 Gy in tumor subvolumes having the highest risk classification without increasing normal tissue complications. Subsequently, we have studied the impact of functional imaging accuracy, and found on the one hand that loss in sensitivity had a large impact on expected local tumor control, which was maximal when a low-risk classification for the remaining low risk PTV was chosen. While on the other hand loss in specificity appeared to have a minimal impact on normal tissue sparing. Therefore, it appears that in order to improve the therapeutic ratio a functional imaging technique with a high sensitivity, rather than specificity, is needed. Last but not least a comparison study between selective boosting IMRT strategies and uniform-boosting IMRT strategies yielding the same EUD to the overall PTV was carried out, and found that selective boosting IMRT considerably improves expected TCP compared to uniform-boosting IMRT, especially when lack of control of the high-risk tumor subvolumes is the cause of expected therapy failure. Furthermore, while selective boosting IMRT, using physical dose-volume objectives, did yield similar rectal and bladder sparing when compared its equivalent uniform-boosting IMRT plan, risk-adaptive radiotherapy, utilizing biological objective functions, did yield a 5.3% reduction in NTCP for the rectum. Hence, in risk-adaptive radiotherapy the

  15. Developments in radiotherapy.

    PubMed

    Svensson, Hans; Möller, Torgil R

    2003-01-01

    A systematic assessment of radiotherapy for cancer was conducted by The Swedish Council on Technology Assessment in Health Care (SBU) in 2001. The assessment included a review of future developments in radiotherapy and an estimate of the potential benefits of improved radiotherapy in Sweden. The conclusions reached from this review can be summarized as: Successively better knowledge is available on dose-response relationships for tumours and normal tissues at different fractionation schedules and treated volumes. Optimization of dose levels and fractionation schedules should improve the treatment outcome. Improved treatment results may be expected with even more optimized fractionation schedules. The radiosensitivity of the tumour is dependent on the availability of free oxygen in the cells. The oxygen effect has been studied for a long time and new knowledge has emerged, but there is still no consensus on the best way to minimize its negative effect in the treatment of hypoxic tumours. Development in imaging techniques is rapid, improving accuracy in outlining targets and organs at risk. This is a prerequisite for advanced treatment planning. More accurate treatment can be obtained using all the computer techniques that are successively made available for calculating dose distributions, controlling the accelerator and multileaf collimator (MLC) and checking patient set-up. Optimized treatment plans can be achieved using inverse dose planning and intensity modulation radiation therapy (IMRT). Optimization algorithms based on biological data from clinical trials could be a part of future dose planning. New genetic markers might be developed that give a measure of the radiation responsiveness of tumours and normal tissue. This could lead to more individualized treatments. New types of radiation sources may be expected: protons, light ions, and improved beams (and compounds) for boron neutron capture therapy (BNCT). Proton accelerators with scanned-beam systems and

  16. Stereotactic radiosurgery - discharge

    MedlinePlus

    Gamma knife - discharge; Cyberknife - discharge; Stereotactic radiotherapy - discharge; Fractionated stereotactic radiotherapy- discharge; Cyclotrons- discharge; Linear accelerator- discharge; Lineacs - discharge; Proton beam radiosurgery - discharge

  17. [Juvenile angiofibroma. Results of radiotherapy].

    PubMed

    Rosset, A; Korzeniowski, S

    1990-01-01

    8 patients with the nasofibromata were treated by radiotherapy in Oncologic Center in Kraków. In most part of these patients tumors exceeded the nasopharynx or gave the massive postoperational recurrencies. Complete regression was obtained in 6 out of 8 cases. The radiation changes are described. The radiotherapy is effective in more advanced and recurrent stages of the juvenile nasofibroma.

  18. [Epoetin alfa in radiotherapy].

    PubMed

    Trodella, L; Balducci, M; Gambacorta, M A; Mantini, G

    1998-01-01

    Sixty per cent of oncologic patients need radiation therapy for cure or palliation. In fact, in most neoplastic diseases, a better local control positively impacts on disease-free survival and overall survival. The efficacy of radiotherapy depends on several factors: while some are tumor-related, others are host-related. Radiobiological phenomena are also important: ionizing radiation is responsible for cell damage (double rupture of DNA chains), mostly an indirect mechanism with the formation of free radicals. Their toxic action is enhanced by the oxygen partial pressure at the cellular level. A number of studies have confirmed that good tissue oxygenation is a function of a high hemoglobin level in the peripheral blood (Hb > or = 13 g/dL). Unfortunately, these values are rarely present in oncologic patients due to the disease-related toxicosis as well as to the therapy induced hematologic toxicity. The treatment of anemia is free of risk for the recent developments in technology which with gene cloning and the technique of recombinant DNA has allowed the production of human recombinant erythropoietin. Erythropoietin is produced by the interstitial cells of renal tubules in response to hypoxia. It prevents apoptosis and promotes erythroid proliferation and differentiation with consequent reticulocyte release and hemoglobin synthesis. It is not completely understood whether the efficacy of radiotherapy depends on hemoglobin values present at the start of irradiation (often less than 12-13 g/dL) or on the higher ones observed during and at the end of radiotherapy. Therefore, preventive systemic erythropoietin therapy in non anemic patients in terms of costs/benefits is at present non sustainable. To the contrary, in patients undergoing radiotherapy to extended fields or aggressive multimodal treatments, for the higher risk of anemia, the early use of this treatment can be hypothesized in case of initial anemia to improve therapy compliance and prevent negative

  19. Fertility impairment in radiotherapy

    PubMed Central

    Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning. PMID:27647982

  20. Imaging in radiotherapy

    NASA Astrophysics Data System (ADS)

    Calandrino, R.; Del Maschio, A.; Cattaneo, G. M.; Castiglioni, I.

    2009-09-01

    The diagnostic methodologies used for the radiotherapy planning have undergone great developments in the last 30 years. Since the 1980s, after the introduction of the CT scanner, the modality for the planning moved beyond the planar 2D assessment to approach a real and more realistic volumetric 3D definition. Consequently the dose distribution, previously obtained by means of an overly simple approximation, became increasingly complex, better tailoring the true shape of the tumour. The final therapeutic improvement has been obtained by a parallel increase in the complexity of the irradiating units: the Linacs for therapy have, in fact, been equipped with a full accessory set capable to modulate the fluence (IMRT) and to check the correct target position continuously during the therapy session (IMRT-IGRT). The multimodal diagnostic approach, which integrates diagnostic information, from images of the patient taken with CT, NMR, PET and US, further improves the data for a biological and topological optimization of the radiotherapy plan and consequently of the dose distribution in the Planning Target Volume. Proteomic and genomic analysis will be the next step in tumour diagnosis. These methods will provide the planners with further information, for a true personalization of the treatment regimen and the assessment of the predictive essays for each tumour and each patient.

  1. Fertility impairment in radiotherapy

    PubMed Central

    Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning.

  2. Fertility impairment in radiotherapy.

    PubMed

    Biedka, Marta; Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning. PMID:27647982

  3. [External radiotherapy for hepatocellular carcinoma].

    PubMed

    Girard, N; Mornex, F

    2011-02-01

    For a long time radiotherapy has been excluded from the therapeutic strategy for hepatocellular carcinoma, given its significant toxicity on the non-tumoral liver parenchyma. Conformal radiation is a recent advance in the field of radiotherapy, allowing dose escalation and combination with other therapeutic options for hepatocellular carcinoma, including trans-arterial chemo-embolization. Conformal radiotherapy is associated with interesting features, especially in cirrhotic patients: wide availability, non-invasiveness, possibility to target multiple localizations anywhere within the liver parenchyma, and favorable tolerance profile even in patients with cirrhosis and/or in a poor medical condition. Recently, radiation delivery has been optimized through several technical developments: respiratory gating and intensity-modulated radiotherapy, which allow a better focalization of the ballistics, stereotactic techniques and proton-beam radiotherapy, whose availability is currently limited in Europe. Given the high response rates of hepatocellular carcinoma to radiation, conformal radiotherapy may be regarded as a curative-intent treatment for hepatocellular carcinoma, similar to surgery and per-cutaneous techniques. Yet the impact of radiotherapy has to be evaluated in randomized trials to better integrate in the complex therapeutic algorithm of hepatocellular carcinoma.

  4. Investigation of the robustness of adaptive neuro-fuzzy inference system for tracking moving tumors in external radiotherapy.

    PubMed

    Torshabi, Ahmad Esmaili

    2014-12-01

    In external radiotherapy of dynamic targets such as lung and breast cancers, accurate correlation models are utilized to extract real time tumor position by means of external surrogates in correlation with the internal motion of tumors. In this study, a correlation method based on the neuro-fuzzy model is proposed to correlate the input external motion data with internal tumor motion estimation in real-time mode, due to its robustness in motion tracking. An initial test of the performance of this model was reported in our previous studies. In this work by implementing some modifications it is resulted that ANFIS is still robust to track tumor motion more reliably by reducing the motion estimation error remarkably. After configuring new version of our ANFIS model, its performance was retrospectively tested over ten patients treated with Synchrony Cyberknife system. In order to assess the performance of our model, the predicted tumor motion as model output was compared with respect to the state of the art model. Final analyzed results show that our adaptive neuro-fuzzy model can reduce tumor tracking errors more significantly, as compared with ground truth database and even tumor tracking methods presented in our previous works. PMID:25412886

  5. Development of targeted radiotherapy systems

    NASA Astrophysics Data System (ADS)

    Ferro, Guillermina; Murphy, Consuelo A.; Villarreal, José E.; Pedraza, Martha; García, Laura; Tendilla, José I.; Paredes, Lydia

    2001-10-01

    Conventional or external beam radiotherapy, has been a viable alternative for cancer treatment. Although this technique is effective, its use is limited if the patient has multiple malignant lesions (metastases). An alternative approach is based on the design of radiopharmaceuticals that, to be administered in the patient, are directed specifically toward the target cell producing a selective radiation delivery. This treatment is known as targeted radiotherapy. We have summarized and discussed some results related to our investigations on the development of targeted radiotherapy systems, including aspects of internal dosimetry.

  6. [Task sharing with radiotherapy technicians in image-guided radiotherapy].

    PubMed

    Diaz, O; Lorchel, F; Revault, C; Mornex, F

    2013-10-01

    The development of accelerators with on-board imaging systems now allows better target volumes reset at the time of irradiation (image-guided radiotherapy [IGRT]). However, these technological advances in the control of repositioning led to a multiplication of tasks for each actor in radiotherapy and increase the time available for the treatment, whether for radiotherapy technicians or radiation oncologists. As there is currently no explicit regulatory framework governing the use of IGRT, some institutional experiments show that a transfer is possible between radiation oncologists and radiotherapy technicians for on-line verification of image positioning. Initial training for every technical and drafting procedures within institutions will improve audit quality by reducing interindividual variability. PMID:24007955

  7. Robotic Image-Guided Stereotactic Radiotherapy, for Isolated Recurrent Primary, Lymph Node or Metastatic Prostate Cancer

    SciTech Connect

    Jereczek-Fossa, Barbara Alicja; Beltramo, Giancarlo; Fariselli, Laura; Fodor, Cristiana; Santoro, Luigi; Vavassori, Andrea; Zerini, Dario; Gherardi, Federica; Ascione, Carmen; Bossi-Zanetti, Isa; Mauro, Roberta; Bregantin, Achille; Bianchi, Livia Corinna; De Cobelli, Ottavio; Orecchia, Roberto

    2012-02-01

    Purpose: To evaluate the outcome of robotic CyberKnife (Accuray, Sunnyvale, CA)-based stereotactic radiotherapy (CBK-SRT) for isolated recurrent primary, lymph node, or metastatic prostate cancer. Methods and Materials: Between May 2007 and December 2009, 34 consecutive patients/38 lesions were treated (15 patients reirradiated for local recurrence [P], 4 patients reirradiated for anastomosis recurrence [A], 16 patients treated for single lymph node recurrence [LN], and 3 patients treated for single metastasis [M]). In all but 4 patients, [{sup 11}C]choline positron emission tomography/computed tomography was performed. CBK-SRT consisted of reirradiation and first radiotherapy in 27 and 11 lesions, respectively. The median CBK-SRT dose was 30 Gy in 4.5 fractions (P, 30 Gy in 5 fractions; A, 30 Gy in 5 fractions; LN, 33 Gy in 3 fractions; and M, 36 Gy in 3 fractions). In 18 patients (21 lesions) androgen deprivation was added to CBK-SRT (median duration, 16.6 months). Results: The median follow-up was 16.9 months. Acute toxicity included urinary events (3 Grade 1, 2 Grade 2, and 2 Grade 3 events) and rectal events (1 Grade 1 event). Late toxicity included urinary events (3 Grade 1, 2 Grade 2, and 2 Grade 3 events) and rectal events (1 Grade 1 event and 1 Grade 2 event). Biochemical response was observed in 32 of 38 evaluable lesions. Prostate-specific antigen stabilization was seen for 4 lesions, and in 2 cases prostate-specific antigen progression was reported. The 30-month progression-free survival rate was 42.6%. Disease progression was observed for 14 lesions (5, 2, 5, and 2 in Groups P, A, LN, and M respectively). In only 3 cases, in-field progression was seen. At the time of analysis (May 2010), 19 patients are alive with no evidence of disease and 15 are alive with disease. Conclusions: CyberKnife-based stereotactic radiotherapy is a feasible approach for isolated recurrent primary, lymph node, or metastatic prostate cancer, offering excellent in-field tumor

  8. Salvage Reirradiaton With Stereotactic Body Radiotherapy for Locally Recurrent Head-and-Neck Tumors

    SciTech Connect

    Cengiz, Mustafa; Ozyigit, Goekhan; Yazici, Goezde; Dogan, Ali; Yildiz, Ferah; Zorlu, Faruk; Guerkaynak, Murat; Gullu, Ibrahim H.; Hosal, Sefik; Akyol, Fadil

    2011-09-01

    Purpose: In this study, we present our results of reirradiation of locally recurrent head-and-neck cancer with image-guided, fractionated, frameless stereotactic body radiotherapy technique. Methods and Materials: From July 2007 to February 2009, 46 patients were treated using the CyberKnife (Accuray, Sunnyvale, CA) at the Department of Radiation Oncology, Hacettepe University, Ankara, Turkey. All patients had recurrent, unresectable, and previously irradiated head-and-neck cancer. The most prominent site was the nasopharynx (32.6%), and the most common histopathology was epidermoid carcinoma. The planning target volume was defined as the gross tumor volume identified on magnetic resonance imaging and computed tomography. There were 22 female and 24 male patients. Median age was 53 years (range, 19-87 years). The median tumor dose with stereotactic body radiotherapy was 30 Gy (range, 18-35 Gy) in a median of five (range, one to five) fractions. Results: Of 37 patients whose response to therapy was evaluated, 10 patients (27%) had complete tumor regression, 11 (29.8%) had partial response, and 10 (27%) had stable disease. Ultimate local disease control was achieved in 31 patients (83.8%). The overall survival was 11.93 months in median (ranged, 11.4 - 17.4 months), and the median progression free survival was 10.5 months. One-year progression-free survival and overall survival were 41% and 46%, respectively. Grade II or greater long-term complications were observed in 6 (13.3%) patients. On follow-up, 8 (17.3%) patients had carotid blow-out syndrome, and 7 (15.2%) patients died of bleeding from carotid arteries. We discovered that this fatal syndrome occurred only in patients with tumor surrounding carotid arteries and carotid arteries receiving all prescribed dose. Conclusions: Stereotactic body radiotherapy is an appealing treatment option for patients with recurrent head-and-neck cancer previously treated with radiation to high doses. Good local control with

  9. [Hepatic tumors and radiotherapy].

    PubMed

    Rio, E; Mornex, F; Peiffert, D; Huertas, A

    2016-09-01

    Recent technological developments led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumors as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. For hepatocellular carcinoma 5 to 10cm (or more), a conformational radiation with or without intensity modulation is performed. Stereotactic body radiotherapy (SBRT) is being evaluated and is increasingly proposed as an alternative to radiofrequency ablative treatment for primary or secondary tumors (typically less than 5cm). Tumor (and liver) movements induced by respiratory motions must be taken into account. Strict dosimetric criteria must be met with particular attention to the dose-volume histograms to liver and the hollow organs, including cases of SBRT. PMID:27521035

  10. Medical Applications: Proton Radiotherapy

    NASA Astrophysics Data System (ADS)

    Keppel, Cynthia

    2009-05-01

    Proton therapy is a highly advanced and precise form of radiation treatment for cancer. Due to the characteristic Bragg peak associated with ion energy deposition, proton therapy provides the radiation oncologist with an improved method of treatment localization within a patient, as compared with conventional radiation therapy using X-rays or electrons. Controlling disease and minimizing side effects are the twin aims of radiation treatment. Proton beams enhance the opportunity for both by facilitating maximal dose to tumor and minimal dose to surrounding tissue. In the United States, five proton radiotherapy centers currently treat cancer patients, with more in the construction phase. New facilities and enabling technologies abound. An overview of the treatment modality generally, as well as of the capabilities and research planned for the field and for the Hampton University Proton Therapy Institute in particular, will be presented.

  11. Smoothing of respiratory motion traces for motion-compensated radiotherapy

    SciTech Connect

    Ernst, Floris; Schlaefer, Alexander; Schweikard, Achim

    2010-01-15

    Purpose: The CyberKnife system has been used successfully for several years to radiosurgically treat tumors without the need for stereotactic fixation or sedation of the patient. It has been shown that tumor motion in the lung, liver, and pancreas can be tracked with acceptable accuracy and repeatability. However, highly precise targeting for tumors in the lower abdomen, especially for tumors which exhibit strong motion, remains problematic. Reasons for this are manifold, like the slow tracking system operating at 26.5 Hz, and using the signal from the tracking camera ''as is''. Since the motion recorded with the camera is used to compensate for system latency by prediction and the predicted signal is subsequently used to infer the tumor position from a correlation model based on x-ray imaging of gold fiducials around the tumor, camera noise directly influences the targeting accuracy. The goal of this work is to establish the suitability of a new smoothing method for respiratory motion traces used in motion-compensated radiotherapy. The authors endeavor to show that better prediction--With a lower rms error of the predicted signal--and/or smoother prediction is possible using this method. Methods: The authors evaluated six commercially available tracking systems (NDI Aurora, PolarisClassic, Polaris Vicra, MicronTracker2 H40, FP5000, and accuTrack compact). The authors first tracked markers both stationary and while in motion to establish the systems' noise characteristics. Then the authors applied a smoothing method based on the a trous wavelet decomposition to reduce the devices' noise level. Additionally, the smoothed signal of the moving target and a motion trace from actual human respiratory motion were subjected to prediction using the MULIN and the nLMS{sub 2} algorithms. Results: The authors established that the noise distribution for a static target is Gaussian and that when the probe is moved such as to mimic human respiration, it remains Gaussian with the

  12. Dosimetric verification of stereotactic radiosurgery/stereotactic radiotherapy dose distributions using Gafchromic EBT3

    SciTech Connect

    Cusumano, Davide; Fumagalli, Maria L.; Marchetti, Marcello; Fariselli, Laura; De Martin, Elena

    2015-10-01

    Aim of this study is to examine the feasibility of using the new Gafchromic EBT3 film in a high-dose stereotactic radiosurgery and radiotherapy quality assurance procedure. Owing to the reduced dimensions of the involved lesions, the feasibility of scanning plan verification films on the scanner plate area with the best uniformity rather than using a correction mask was evaluated. For this purpose, signal values dispersion and reproducibility of film scans were investigated. Uniformity was then quantified in the selected area and was found to be within 1.5% for doses up to 8 Gy. A high-dose threshold level for analyses using this procedure was established evaluating the sensitivity of the irradiated films. Sensitivity was found to be of the order of centiGray for doses up to 6.2 Gy and decreasing for higher doses. The obtained results were used to implement a procedure comparing dose distributions delivered with a CyberKnife system to planned ones. The procedure was validated through single beam irradiation on a Gafchromic film. The agreement between dose distributions was then evaluated for 13 patients (brain lesions, 5 Gy/die prescription isodose ~80%) using gamma analysis. Results obtained using Gamma test criteria of 5%/1 mm show a pass rate of 94.3%. Gamma frequency parameters calculation for EBT3 films showed to strongly depend on subtraction of unexposed film pixel values from irradiated ones. In the framework of the described dosimetric procedure, EBT3 films proved to be effective in the verification of high doses delivered to lesions with complex shapes and adjacent to organs at risk.

  13. Stereotactic Body Radiotherapy for Localized Prostate Cancer: Interim Results of a Prospective Phase II Clinical Trial

    SciTech Connect

    King, Christopher R. Brooks, James D.; Gill, Harcharan; Pawlicki, Todd; Cotrutz, Cristian; Presti, Joseph C.

    2009-03-15

    Purpose: The radiobiology of prostate cancer favors a hypofractionated dose regimen. We report results of a prospective Phase II clinical trial of stereotactic body radiotherapy (SBRT) for localized prostate cancer. Methods and Materials: Forty-one low-risk prostate cancer patients with 6 months' minimum follow-up received 36.25 Gy in five fractions of 7.25 Gy with image-guided SBRT alone using the CyberKnife. The early (<3 months) and late (>6 months) urinary and rectal toxicities were assessed using validated quality of life questionnaires (International Prostate Symptom Score, Expanded Prostate Cancer Index Composite) and the Radiation Therapy Oncology Group (RTOG) toxicity criteria. Patterns of prostate-specific antigen (PSA) response are analyzed. Results: The median follow-up was 33 months. There were no RTOG Grade 4 acute or late rectal/urinary complications. There were 2 patients with RTOG Grade 3 late urinary toxicity and none with RTOG Grade 3 rectal complications. A reduced rate of severe rectal toxicities was observed with every-other-day vs. 5 consecutive days treatment regimen (0% vs. 38%, p = 0.0035). A benign PSA bounce (median, 0.4 ng/mL) was observed in 12 patients (29%) occurring at 18 months (median) after treatment. At last follow-up, no patient has had a PSA failure regardless of biochemical failure definition. Of 32 patients with 12 months minimum follow-up, 25 patients (78%) achieved a PSA nadir {<=}0.4 ng/mL. A PSA decline to progressively lower nadirs up to 3 years after treatment was observed. Conclusions: The early and late toxicity profile and PSA response for prostate SBRT are highly encouraging. Continued accrual and follow-up will be necessary to confirm durable biochemical control rates and low toxicity profiles.

  14. Quantifying variability of intrafractional target motion in stereotactic body radiotherapy for lung cancers.

    PubMed

    Chan, Mark K H; Kwong, Dora L W; Tam, Eric; Tong, Anthony; Ng, Sherry C Y

    2013-09-06

    In lung stereotactic body radiotherapy (SBRT), variability of intrafractional target motion can negate the potential benefits of four-dimensional (4D) treatment planning that aims to account for the dosimetric impacts of organ motion. This study used tumor motion data obtained from CyberKnife SBRT treatments to quantify the reproducibility of probability motion function (pmf) of 37 lung tumors. The reproducibility of pmf was analyzed with and without subtracting the intrafractional baseline drift from the original motion data. Statistics of intrafractional tumor motion including baseline drift, target motion amplitude and period, were also calculated. The target motion amplitude significantly correlates with variations (1SD) of motion amplitude and baseline drift. Significant correlation between treatment time and variations (1 SD) of motion amplitude was observed in anterior-posterior (AP) motion, but not in craniocaudal (CC) and left-right (LR) motion. The magnitude of AP and LR baseline drifts significantly depend on the treatment time, while the CC baseline drift does not. The reproducibility of pmf as a function of time can be well described by a two-exponential function with a fast and slow component. The reproducibility of pmf is over 60% for the CC motion and over 50% for the AP and LR motions when baseline variations were subtracted from the original motion data. It decreases to just over 30% for the CC motion and about 20% for the AP and LR motion, otherwise. 4D planning has obvious limitations due to variability of intrafractional target motion. To account for potential risks of overdosing critical organs, it is important to simulate the dosimetric impacts of intra- and interfractional baseline drift using population statistics obtained from SBRT treatments.

  15. A comparative study of small field total scatter factors and dose profiles using plastic scintillation detectors and other stereotactic dosimeters: The case of the CyberKnife

    SciTech Connect

    Morin, J.; Beliveau-Nadeau, D.; Chung, E.; Seuntjens, J.; Theriault, D.; Archambault, L.; Beddar, S.; Beaulieu, L.

    2013-01-15

    Purpose: Small-field dosimetry is challenging, and the main limitations of most dosimeters are insufficient spatial resolution, water nonequivalence, and energy dependence. The purpose of this study was to compare plastic scintillation detectors (PSDs) to several commercial stereotactic dosimeters by measuring total scatter factors and dose profiles on a CyberKnife system. Methods: Two PSDs were developed, having sensitive volumes of 0.196 and 0.785 mm{sup 3}, and compared with other detectors. The spectral discrimination method was applied to subtract Cerenkov light from the signal. Both PSDs were compared to four commercial stereotactic dosimeters by measuring total scatter factors, namely, an IBA dosimetry stereotactic field diode (SFD), a PTW 60008 silicon diode, a PTW 60012 silicon diode, and a microLion. The measured total scatter factors were further compared with those of two independent Monte Carlo studies. For the dose profiles, two commercial detectors were used for the comparison, i.e., a PTW 60012 silicon diode and Gafchromics EBT2. Total scatter factors for a CyberKnife system were measured in circular fields with diameters from 5 to 60 mm. Dose profiles were measured for the 5- and 60-mm cones. The measurements were performed in a water tank at a 1.5-cm depth and an 80-cm source-axis distance. Results: The total scatter factors measured using all the detectors agreed within 1% with the Monte Carlo values for cones of 20 mm or greater in diameter. For cones of 10-20 mm in diameter, the PTW 60008 silicon diode was the only dosimeter whose measurements did not agree within 1% with the Monte Carlo values. For smaller fields (<10 mm), each dosimeter type showed different behaviors. The silicon diodes over-responded because of their water nonequivalence; the microLion and 1.0-mm PSD under-responded because of a volume-averaging effect; and the 0.5-mm PSD was the only detector within the uncertainties of the Monte Carlo simulations for all the cones. The

  16. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy.

    PubMed

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  17. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy

    PubMed Central

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  18. Sci—Sat AM: Stereo — 07: Suitability of a plastic scintillator dosimeter for composite clinical fields delivered using the Cyberknife robotic radiosurgery system

    SciTech Connect

    Vandervoort, E.; Szanto, J.; Christiansen, E.

    2014-08-15

    Plastic scintillation dosimeters (PSDs) have favourable characteristics for small and composite field dosimetry in radiosurgery, however, imperfect corrections for the Cerenkov radiation contamination could limit their accuracy for complex deliveries. In this work, we characterize the dose and dose-rate linearity, directional dependence, and compare output factors with other stereotactic detectors for a new commercially available PSD (Exradin W1). We provide some preliminary comparisons of planned and measured dose for composite fields delivered clinically by a Cyberknife radiosurgery system. The W1 detector shows good linearity with dose (<0.5%) and dose rate (<0.8%) relative to the signal obtained using an ion chamber under the same conditions. A maximum difference of 2% was observed depending on the detector's angular orientation. Output factors for all detectors agree within a range of ±3.2% and ±1.5% for the 5 and 7.5 mm collimators, respectively, provided Monte-Carlo corrections for detector effects are applied to diode and ion chambers (without corrections the range is ±5.5% and ±3.1% for these two collimators). For clinical beam deliveries using 5 and 7.5 mm collimators, four of the six patients showed better agreement with planned dose for the PSD detector compared to a micro ion chamber. Two of the six patients investigated, however, showed 5% differences between PSD and planned dose, film measurements and the ratio of PSD and micro ion chamber signal suggest that further investigation is warranted for these plans. The W1 detector is a promising tool for stereotactic plan verification under the challenging dosimetric conditions of stereotactic radiosurgery.

  19. Complications from radiotherapy.

    PubMed

    Dhermain, Frédéric; Barani, Igor J

    2016-01-01

    Radiotherapy (RT) of the brain is associated with significant stigma in the neuro-oncology community. This is primarily because of the potentially severe complications with which it may be associated. These complications, especially in subacute and latent settings, are often unpredictable, potentially progressive, and irreversible. The onset of complications may start from the first fraction of 2 Gy, continuing over several months after end of RT with persistent drowsiness and apathy. It may also extend over many years with progressive onset of neurocognitive impairments such as memory decline, and diminished focus/attention. For long-term survivors, such as young patients irradiated for a favorable low-grade glioma, quality of life can be seriously impacted by RT. It is essential, as in the pediatric field, to propose patient-specific regimens from the very outset of therapy. The use of molecular biomarkers to better predict survival, control of comorbidities along with judicious use of medications such as steroids and antiepileptics, improved targeting with the help of modern imaging and RT techniques, modulation of the dose, and fractionation aimed at limiting integral dose to the healthy brain all have the potential to minimize treatment-related complications while maintaining the therapeutic efficacy for which RT is known. Sparing "radiosensitive" areas such as hippocampi could have a modest but measurable impact with regard to cognitive preservation, an effect that can possibly be enhanced when used in conjunction with memantine and/or donepezil. PMID:26948357

  20. [Adaptative radiotherapy: The case for MRI-guided radiotherapy].

    PubMed

    Maingon, P

    2016-10-01

    The concept of image-guided radiotherapy benefits from the development of magnetic resonance imaging (MRI) associated with different capacities of tissue analyses such as spectroscopy or diffusion analysis. The production of devices allowing the repositioning of patients through MRI represents a strong added value without delivering any additional dose to the patient while the optimization of the adaptative strategies are facilitated by a better contrast of the soft tissues compared to the scanner. The advantages of MRI are well demonstrated for brain tumours, head and neck carcinomas, pelvic tumors, mediastinal malignancies, gastrointestinal tract diseases. Adaptative radiotherapy inaugurates a new area of radiotherapy with different modalities. Several technological solutions are provided or discussed allowing the patients to benefit from thses new technologies as soon as possible.

  1. [Adaptative radiotherapy: The case for MRI-guided radiotherapy].

    PubMed

    Maingon, P

    2016-10-01

    The concept of image-guided radiotherapy benefits from the development of magnetic resonance imaging (MRI) associated with different capacities of tissue analyses such as spectroscopy or diffusion analysis. The production of devices allowing the repositioning of patients through MRI represents a strong added value without delivering any additional dose to the patient while the optimization of the adaptative strategies are facilitated by a better contrast of the soft tissues compared to the scanner. The advantages of MRI are well demonstrated for brain tumours, head and neck carcinomas, pelvic tumors, mediastinal malignancies, gastrointestinal tract diseases. Adaptative radiotherapy inaugurates a new area of radiotherapy with different modalities. Several technological solutions are provided or discussed allowing the patients to benefit from thses new technologies as soon as possible. PMID:27599686

  2. Voice following radiotherapy.

    PubMed

    Stoicheff, M L

    1975-04-01

    This study was undertaken to provide information on the voice of patients following radiotherapy for glottic cancer. Part I presents findings from questionnaires returned by 227 of 235 patients successfully irradiated for glottic cancer from 1960 through 1971. Part II presents preliminary findings on the speaking fundamental frequencies of 22 irradiated patients. Normal to near-normal voice was reported by 83 percent of the 227 patients; however, 80 percent did indicate persisting vocal difficulties such as fatiguing of voice with much usage, inability to sing, reduced loudness, hoarse voice quality and inability to shout. Amount of talking during treatments appeared to affect length of time for voice to recover following treatments in those cases where it took from nine to 26 weeks; also, with increasing years since treatment, patients rated their voices more favorably. Smoking habits following treatments improved significantly with only 27 percent smoking heavily as compared with 65 percent prior to radiation therapy. No correlation was found between smoking (during or after treatments) and vocal ratings or between smoking and length of time for voice to recover. There was no relationship found between reported vocal ratings and stage of the disease. Data on mean speaking fundamental frequency seem to indicate a trend toward lower frequencies in irradiated patients as compared with normals. A trend was also noted in both irradidated and control groups for lower speaking fundamental frequencies in heavy smokers compared with non-smokers or previous smokers. These trends would indicate some vocal cord thickening or edema in irradiated patients and in heavy smokers. It is suggested that the study of irradiated patients' voices before, during and following treatments by means of audio, aerodynamic and acoustic instrumentation would yield additional information of diagnostic value on recovery of laryngeal function. It is also suggested that the voice pathologist could

  3. Introduction to suspension levels: radiotherapy.

    PubMed

    Horton, P; Lillicrap, S; Lamm, I-L; Lehmann, W

    2013-02-01

    In 2007, the European Commission (EC) commissioned a group of experts to undertake the revision of Report Radiation Protection (RP 91) 'Criteria for acceptability of radiological (including radiotherapy) and nuclear medicine installations' written in 1997. The revised draft report was submitted to the EC in 2010, who issued it for public consultation. The EC has commissioned the same group of experts to consider the comments of the public consultation for further improvement of the revised report. The EC intends to publish the final report under its Radiation Report Series as RP 162. This paper describes the background to the selection of the key performance parameters for radiotherapy equipment and sets out the sources of their criteria of acceptability including suspension levels for a wide range of radiotherapy equipment.

  4. Expanding global access to radiotherapy.

    PubMed

    Atun, Rifat; Jaffray, David A; Barton, Michael B; Bray, Freddie; Baumann, Michael; Vikram, Bhadrasain; Hanna, Timothy P; Knaul, Felicia M; Lievens, Yolande; Lui, Tracey Y M; Milosevic, Michael; O'Sullivan, Brian; Rodin, Danielle L; Rosenblatt, Eduardo; Van Dyk, Jacob; Yap, Mei Ling; Zubizarreta, Eduardo; Gospodarowicz, Mary

    2015-09-01

    Radiotherapy is a critical and inseparable component of comprehensive cancer treatment and care. For many of the most common cancers in low-income and middle-income countries, radiotherapy is essential for effective treatment. In high-income countries, radiotherapy is used in more than half of all cases of cancer to cure localised disease, palliate symptoms, and control disease in incurable cancers. Yet, in planning and building treatment capacity for cancer, radiotherapy is frequently the last resource to be considered. Consequently, worldwide access to radiotherapy is unacceptably low. We present a new body of evidence that quantifies the worldwide coverage of radiotherapy services by country. We show the shortfall in access to radiotherapy by country and globally for 2015-35 based on current and projected need, and show substantial health and economic benefits to investing in radiotherapy. The cost of scaling up radiotherapy in the nominal model in 2015-35 is US$26·6 billion in low-income countries, $62·6 billion in lower-middle-income countries, and $94·8 billion in upper-middle-income countries, which amounts to $184·0 billion across all low-income and middle-income countries. In the efficiency model the costs were lower: $14·1 billion in low-income, $33·3 billion in lower-middle-income, and $49·4 billion in upper-middle-income countries-a total of $96·8 billion. Scale-up of radiotherapy capacity in 2015-35 from current levels could lead to saving of 26·9 million life-years in low-income and middle-income countries over the lifetime of the patients who received treatment. The economic benefits of investment in radiotherapy are very substantial. Using the nominal cost model could produce a net benefit of $278·1 billion in 2015-35 ($265·2 million in low-income countries, $38·5 billion in lower-middle-income countries, and $239·3 billion in upper-middle-income countries). Investment in the efficiency model would produce in the same period an even

  5. Expanding global access to radiotherapy.

    PubMed

    Atun, Rifat; Jaffray, David A; Barton, Michael B; Bray, Freddie; Baumann, Michael; Vikram, Bhadrasain; Hanna, Timothy P; Knaul, Felicia M; Lievens, Yolande; Lui, Tracey Y M; Milosevic, Michael; O'Sullivan, Brian; Rodin, Danielle L; Rosenblatt, Eduardo; Van Dyk, Jacob; Yap, Mei Ling; Zubizarreta, Eduardo; Gospodarowicz, Mary

    2015-09-01

    Radiotherapy is a critical and inseparable component of comprehensive cancer treatment and care. For many of the most common cancers in low-income and middle-income countries, radiotherapy is essential for effective treatment. In high-income countries, radiotherapy is used in more than half of all cases of cancer to cure localised disease, palliate symptoms, and control disease in incurable cancers. Yet, in planning and building treatment capacity for cancer, radiotherapy is frequently the last resource to be considered. Consequently, worldwide access to radiotherapy is unacceptably low. We present a new body of evidence that quantifies the worldwide coverage of radiotherapy services by country. We show the shortfall in access to radiotherapy by country and globally for 2015-35 based on current and projected need, and show substantial health and economic benefits to investing in radiotherapy. The cost of scaling up radiotherapy in the nominal model in 2015-35 is US$26·6 billion in low-income countries, $62·6 billion in lower-middle-income countries, and $94·8 billion in upper-middle-income countries, which amounts to $184·0 billion across all low-income and middle-income countries. In the efficiency model the costs were lower: $14·1 billion in low-income, $33·3 billion in lower-middle-income, and $49·4 billion in upper-middle-income countries-a total of $96·8 billion. Scale-up of radiotherapy capacity in 2015-35 from current levels could lead to saving of 26·9 million life-years in low-income and middle-income countries over the lifetime of the patients who received treatment. The economic benefits of investment in radiotherapy are very substantial. Using the nominal cost model could produce a net benefit of $278·1 billion in 2015-35 ($265·2 million in low-income countries, $38·5 billion in lower-middle-income countries, and $239·3 billion in upper-middle-income countries). Investment in the efficiency model would produce in the same period an even

  6. [Head and neck adaptive radiotherapy].

    PubMed

    Graff, P; Huger, S; Kirby, N; Pouliot, J

    2013-10-01

    Onboard volumetric imaging systems can provide accurate data of the patient's anatomy during a course of head and neck radiotherapy making it possible to assess the actual delivered dose and to evaluate the dosimetric impact of complex daily positioning variations and gradual anatomic changes such as geometric variations of tumors and normal tissues or shrinkage of external contours. Adaptive radiotherapy is defined as the correction of a patient's treatment planning to adapt for individual variations observed during treatment. Strategies are developed to selectively identify patients that require replanning because of an intolerable dosimetric drift. Automated tools are designed to limit time consumption. Deformable image registration algorithms are the cornerstones of these strategies, but a better understanding of their limits of validity is required before adaptive radiotherapy can be safely introduced to daily practice. Moreover, strict evaluation of the clinical benefits is yet to be proven.

  7. Clinical quality standards for radiotherapy

    PubMed Central

    2012-01-01

    Aim of the study The technological progress that is currently being witnessed in the areas of diagnostic imaging, treatment planning systems and therapeutic equipment has caused radiotherapy to become a high-tech and interdisciplinary domain involving staff of various backgrounds. This allows steady improvement in therapy results, but at the same time makes the diagnostic, imaging and therapeutic processes more complex and complicated, requiring every stage of those processes to be planned, organized, controlled and improved so as to assure high quality of services provided. The aim of this paper is to present clinical quality standards for radiotherapy as developed by the author. Material and methods In order to develop the quality standards, a comparative analysis was performed between European and Polish legal acts adopted in the period of 1980-2006 and the universal industrial ISO 9001:2008 standard, defining requirements for quality management systems, and relevant articles published in 1984-2009 were reviewed, including applicable guidelines and recommendations of American, international, European and Polish bodies, such as the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy & Oncology (ESTRO), the International Atomic Energy Agency (IAEA), and the Organisation of European Cancer Institutes (OECI) on quality assurance and management in radiotherapy. Results As a result, 352 quality standards for radiotherapy were developed and categorized into the following three groups: 1 – organizational standards; 2 – physico-technical standards and 3 – clinical standards. Conclusion Proposed clinical quality standards for radiotherapy can be used by any institution using ionizing radiation for medical purposes. However, standards are of value only if they are implemented, reviewed, audited and improved, and if there is a clear mechanism in place to monitor and address failure to meet agreed standards. PMID:23788854

  8. Second Malignant Neoplasms Following Radiotherapy

    PubMed Central

    Kumar, Sanath

    2012-01-01

    More than half of all cancer patients receive radiotherapy as a part of their treatment. With the increasing number of long-term cancer survivors, there is a growing concern about the risk of radiation induced second malignant neoplasm [SMN]. This risk appears to be highest for survivors of childhood cancers. The exact mechanism and dose-response relationship for radiation induced malignancy is not well understood, however, there have been growing efforts to develop strategies for the prevention and mitigation of radiation induced cancers. This review article focuses on the incidence, etiology, and risk factors for SMN in various organs after radiotherapy. PMID:23249860

  9. Monte Carlo calculation based on hydrogen composition of the tissue for MV photon radiotherapy.

    PubMed

    Demol, Benjamin; Viard, Romain; Reynaert, Nick

    2015-09-08

    The purpose of this study was to demonstrate that Monte Carlo treatment planning systems require tissue characterization (density and composition) as a function of CT number. A discrete set of tissue classes with a specific composition is introduced. In the current work we demonstrate that, for megavoltage photon radiotherapy, only the hydrogen content of the different tissues is of interest. This conclusion might have an impact on MRI-based dose calculations and on MVCT calibration using tissue substitutes. A stoichiometric calibration was performed, grouping tissues with similar atomic composition into 15 dosimetrically equivalent subsets. To demonstrate the importance of hydrogen, a new scheme was derived, with correct hydrogen content, complemented by oxygen (all elements differing from hydrogen are replaced by oxygen). Mass attenuation coefficients and mass stopping powers for this scheme were calculated and compared to the original scheme. Twenty-five CyberKnife treatment plans were recalculated by an in-house developed Monte Carlo system using tissue density and hydrogen content derived from the CT images. The results were compared to Monte Carlo simulations using the original stoichiometric calibration. Between 300 keV and 3 MeV, the relative difference of mass attenuation coefficients is under 1% within all subsets. Between 10 keV and 20 MeV, the relative difference of mass stopping powers goes up to 5% in hard bone and remains below 2% for all other tissue subsets. Dose-volume histograms (DVHs) of the treatment plans present no visual difference between the two schemes. Relative differences of dose indexes D98, D95, D50, D05, D02, and Dmean were analyzed and a distribution centered around zero and of standard deviation below 2% (3 σ) was established. On the other hand, once the hydrogen content is slightly modified, important dose differences are obtained. Monte Carlo dose planning in the field of megavoltage photon radiotherapy is fully achievable using

  10. [Which rules apply to hypofractionated radiotherapy?].

    PubMed

    Supiot, S; Clément-Colmou, K; Paris, F; Corre, I; Chiavassa, S; Delpon, G

    2015-10-01

    Hypofractionated radiotherapy is now more widely prescribed due to improved targeting techniques (intensity modulated radiotherapy, image-guided radiotherapy and stereotactic radiotherapy). Low dose hypofractionated radiotherapy is routinely administered mostly for palliative purposes. High or very high dose hypofractionated irradiation must be delivered according to very strict procedures since every minor deviation can lead to major changes in dose delivery to the tumor volume and organs at risk. Thus, each stage of the processing must be carefully monitored starting from the limitations and the choice of the hypofractionation technique, tumour contouring and dose constraints prescription, planning and finally dose calculation and patient positioning verification.

  11. Intraoperative radiotherapy: the Japanese experience. [Betatron

    SciTech Connect

    Abe, M.; Takahashi, M.

    1981-07-01

    Clinical results of intraoperative radiotherapy (IOR) which have been obtained since 1964 in Japan were reviewed. In this radiotherapy a cancerocidal dose can be delivered safely to the lesions, since critical organs are shifted from the field so that the lesions may be exposed directly to radiation. Intraoperative radiotherapy has spread in Japan and the number of institutions in which this radiotherapy is performed has continued to increase to a total of 26 in 1979. The total number of patients treated was 717. It has been demonstrated that intraoperative radiotherapy has definite effects on locally advanced abdominal neoplasms and unresectable radioresistant tumors.

  12. Radiotherapy of chondrosarcoma of bone

    SciTech Connect

    Harwood, A.R.; Krajbich, J.I.; Fornasier, V.L.

    1980-06-01

    A retrospective analysis of 31 cases of chondrosarcoma of bone treated by radiotherapy is presented. In comparison with other large series, our group of patients were found to have been unfavourably selected with respect to the known prognostic factors: histology site, adequacy of operative treatment, and presenting symptoms. Twelve patients with primary chondrosarcoma were radically irradiated; 6 of these 12 have been alive and well without tumor for periods ranging from three and a half to 16 years and 3 of these are alive and well for 15 years or more following radiotherapy. The other 6 patients responded or desease stabilized following radiotherapy for periods ranging from 16 months to eight years. One poorly differentiated tumor was radically irradiated and did not respond. Eleven patients were irradiated palliatively, generally with low doses of irradiation, and only 4 responded transiently for periods ranging from three to 12 months. Seven patients with mesenchymal and dedifferentiated tumors were radically irradiated. Four responded or disease stabilized, and 1 of these patients was alive and well at 3 years; 3 did not respond. Six died with distant metastasis. It is concluded that chondrosarcoma of bone is a radioresponsive tumor and the place of radiotherapy in the treatment of this disease and the reason for its being labelled a radioresistant tumor are discussed. The problems of assessing response of chondrosarcoma to therapy are also discussed. It is suggested that chemotherapy may have a role in the management of mesenchymal and dedifferentiated chondrosarcoma.

  13. Pancreatic cancer: chemotherapy and radiotherapy

    PubMed Central

    Andrén-Sandberg, Åke

    2011-01-01

    Pancreatic cancer in many cases appears in a non-curatively resectable stage when the diagnosis is made. Palliative treatment become an option in the patients with advanced stage. The present article reviewed chemotherapy and radiotherapy in various advanced stage of pancreatic cancer. PMID:22540056

  14. Radiotherapy T1 glottic carcinoma

    SciTech Connect

    Zablow, A.I.; Erba, P.S.; Sanfillippo, L.J.

    1989-11-01

    From 1970 to 1985, curative radiotherapy was administered to 63 patients with stage I carcinoma of the true vocal cords. Precision radiotherapeutic technique yields cure rates comparable to surgical results. Good voice quality was preserved in a high percentage of patients.

  15. [Conformal radiotherapy: principles and classification].

    PubMed

    Rosenwald, J C; Gaboriaud, G; Pontvert, D

    1999-01-01

    'Conformal radiotherapy' is the name fixed by usage and given to a new form of radiotherapy resulting from the technological improvements observed during, the last ten years. While this terminology is now widely used, no precise definition can be found in the literature. Conformal radiotherapy refers to an approach in which the dose distribution is more closely 'conformed' or adapted to the actual shape of the target volume. However, the achievement of a consensus on a more specific definition is hampered by various difficulties, namely in characterizing the degree of 'conformality'. We have therefore suggested a classification scheme be established on the basis of the tools and the procedures actually used for all steps of the process, i.e., from prescription to treatment completion. Our classification consists of four levels: schematically, at level 0, there is no conformation (rectangular fields); at level 1, a simple conformation takes place, on the basis of conventional 2D imaging; at level 2, a 3D reconstruction of the structures is used for a more accurate conformation; and level 3 includes research and advanced dynamic techniques. We have used our personal experience, contacts with colleagues and data from the literature to analyze all the steps of the planning process, and to define the tools and procedures relevant to a given level. The corresponding tables have been discussed and approved at the European level within the Dynarad concerted action. It is proposed that the term 'conformal radiotherapy' be restricted to procedures where all steps are at least at level 2.

  16. Predictive Parameters of CyberKnife Fiducial-less (XSight Lung) Applicability for Treatment of Early Non-Small Cell Lung Cancer: A Single-Center Experience

    SciTech Connect

    Bahig, Houda; Campeau, Marie-Pierre; Vu, Toni; Doucet, Robert; Béliveau Nadeau, Dominic; Fortin, Bernard; Roberge, David; Lambert, Louise; Carrier, Jean-François; Filion, Edith

    2013-11-01

    Purpose: To determine which parameters allow for CyberKnife fiducial-less tumor tracking in stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer. Methods and Materials: A total of 133 lung SBRT patients were preselected for direct soft-tissue tracking based on manufacturer recommendations (peripherally located tumors ≥1.5 cm with a dense appearance) and staff experience. Patients underwent a tumor visualization test to verify adequate detection by the tracking system (orthogonal radiographs). An analysis of potential predictors of successful tumor tracking was conducted looking at: tumor stage, size, histology, tumor projection on the vertebral column or mediastinum, distance to the diaphragm, lung-to-soft tissue ratio, and patient body mass index. Results: Tumor visualization was satisfactory for 88 patients (66%) and unsatisfactory for 45 patients (34%). Median time to treatment start was 6 days in the success group (range, 2-18 days) and 15 days (range, 3-63 days) in the failure group. A stage T2 (P=.04), larger tumor size (volume of 15.3 cm{sup 3} vs 6.5 cm{sup 3} in success and failure group, respectively) (P<.0001), and higher tumor density (0.86 g/cm{sup 3} vs 0.79 g/cm{sup 3}) were predictive of adequate detection. There was a 63% decrease in failure risk with every 1-cm increase in maximum tumor dimension (relative risk for failure = 0.37, CI=0.23-0.60, P=.001). A diameter of 3.6 cm predicted a success probability of 80%. Histology, lung-to-soft tissue ratio, distance to diaphragm, patient's body mass index, and tumor projection on vertebral column and mediastinum were not found to be predictive of success. Conclusions: Tumor size, volume, and density were the most predictive factors of a successful XSight Lung tumor tracking. Tumors >3.5 cm have ≥80% chance of being adequately visualized and therefore should all be considered for direct tumor tracking.

  17. SU-E-T-587: Monte Carlo Versus Ray-Tracing for Treatment Planning Involving CNS Tumors On the MultiPlan System for CyberKnife Radiosurgery

    SciTech Connect

    Forbang, R Teboh

    2014-06-01

    Purpose: MultiPlan, the treatment planning system for the CyberKnife Robotic Radiosurgery system offers two approaches to dose computation, namely Ray-Tracing (RT), the default technique and Monte Carlo (MC), an option. RT is deterministic, however it accounts for primary heterogeneity only. MC on the other hand has an uncertainty associated with the calculation results. The advantage is that in addition, it accounts for heterogeneity effects on the scattered dose. Not all sites will benefit from MC. The goal of this work was to focus on central nervous system (CNS) tumors and compare dosimetrically, treatment plans computed with RT versus MC. Methods: Treatment plans were computed using both RT and MC for sites covering (a) the brain (b) C-spine (c) upper T-spine (d) lower T-spine (e) L-spine and (f) sacrum. RT was first used to compute clinically valid treatment plans. Then the same treatment parameters, monitor units, beam weights, etc., were used in the MC algorithm to compute the dose distribution. The plans were then compared for tumor coverage to illustrate the difference if any. All MC calculations were performed at a 1% uncertainty. Results: Using the RT technique, the tumor coverage for the brain, C-spine (C3–C7), upper T-spine (T4–T6), lower T-spine (T10), Lspine (L2) and sacrum were 96.8%, 93.1%, 97.2%, 87.3%, 91.1%, and 95.3%. The corresponding tumor coverage based on the MC approach was 98.2%, 95.3%, 87.55%, 88.2%, 92.5%, and 95.3%. It should be noted that the acceptable planning target coverage for our clinical practice is >95%. The coverage can be compromised for spine tumors to spare normal tissues such as the spinal cord. Conclusion: For treatment planning involving the CNS, RT and MC appear to be similar for most sites but for the T-spine area where most of the beams traverse lung tissue. In this case, MC is highly recommended.

  18. Intraoperative radiotherapy for breast cancer

    PubMed Central

    Williams, Norman R.; Pigott, Katharine H.; Brew-Graves, Chris

    2014-01-01

    Intra-operative radiotherapy (IORT) as a treatment for breast cancer is a relatively new technique that is designed to be a replacement for whole breast external beam radiotherapy (EBRT) in selected women suitable for breast-conserving therapy. This article reviews twelve reasons for the use of the technique, with a particular emphasis on targeted intra-operative radiotherapy (TARGIT) which uses X-rays generated from a portable device within the operating theatre immediately after the breast tumour (and surrounding margin of healthy tissue) has been removed. The delivery of a single fraction of radiotherapy directly to the tumour bed at the time of surgery, with the capability of adding EBRT at a later date if required (risk-adaptive technique) is discussed in light of recent results from a large multinational randomised controlled trial comparing TARGIT with EBRT. The technique avoids irradiation of normal tissues such as skin, heart, lungs, ribs and spine, and has been shown to improve cosmetic outcome when compared with EBRT. Beneficial aspects to both institutional and societal economics are discussed, together with evidence demonstrating excellent patient satisfaction and quality of life. There is a discussion of the published evidence regarding the use of IORT twice in the same breast (for new primary cancers) and in patients who would never be considered for EBRT because of their special circumstances (such as the frail, the elderly, or those with collagen vascular disease). Finally, there is a discussion of the role of the TARGIT Academy in developing and sustaining high standards in the use of the technique. PMID:25083504

  19. Clinical study on the influence of motion and other factors on stereotactic radiotherapy in the treatment of adrenal gland tumor

    PubMed Central

    Wang, Jingsheng; Li, Fengtong; Dong, Yang; Song, Yongchun; Yuan, Zhiyong

    2016-01-01

    Background The aim of this study was to investigate the adrenal tumor motion law and influence factors in the treatment of adrenal gland tumor and provide a reference value basis for determining the planning target volume margins for therapy. Materials and methods The subjects considered in this study were 38 adrenal tumor patients treated with CyberKnife with the placement of 45 gold fiducials. Fiducials were implanted into each adrenal tumor using β-ultrasonic guidance. Motion amplitudes of gold fiducials were measured with a Philips SLS simulator and motion data in the left–right, anterior–posterior, and cranio–caudal directions were obtained. Multiple linear regression models were used to analyze influencing factors. t-Test was used for motion amplitude comparison of different tumor locations along the z-axis. Results The motion distances were 0.1–0.4 cm (0.27±0.07 cm), 0.1–0.5 cm (0.31±0.11 cm), and 0.5–1.2 cm (0.87±0.21 cm) along the x-, y-, and z-axes, respectively. Motion amplitude along the z-axis may be affected by tumor location, but movement along the other axes was not affected by age, height, body mass, location, and size. Conclusion The maximum motion distance was along the z-axis. Therefore, this should be the main consideration when defining the planning target volume safety margin. Due to the proximity of the liver, adrenal gland tumor motion amplitude was smaller on the right than the left. This study analyzed adrenal tumor motion amplitude data to evaluate how motion and other factors influence the treatment of adrenal tumor with a goal of providing a reference for stereotactic radiotherapy boundary determination. PMID:27486331

  20. SU-E-T-545: A MLC-Equipped Robotic Radiosurgery-Radiotherapy Combined System in Treating Hepatic Lesions: Delivery Efficiency as Compared to a Standard Linac for Treating Hepatic Lesions

    SciTech Connect

    Jin, L; Price, R; Wang, L; Meyer, J; Ma, C; Fan, J

    2014-06-01

    Purpose: The CyberKnife (CK) M6 Series introduced a mulitleaf collimator (MLC) beam for extending its capability to the conventional radiotherapy. This work is to investigate delivery efficiency of this system as compared to a standard Varian linac when treating hepatic lesions. Methods: Nine previously treated patients were divided into three groups with three patients in each. Group one: fractionated radiotherapy; Group two: SBRT-like treatments and Group three: fractionated radiotherapy targeting two PTVs. The clinically used plans were generated with the Eclipse treatment planning system (TPS). We re-planned these cases using a Mulitplan (MP) TPS for the CK M6 and normalized to the same PTV dose coverage. CK factors (CF) (defined as modulation scaling factor in this work), number of nodes (NN), number of MLC segments (NS) and beam delivery time (BT) with an estimated image interval of 60 seconds, were used for evaluation of delivery efficiency. Results: Generated plans from the MP and Eclipse TPS demonstrated the similar quality in terms of PTV confomality index, minimum and maximum PTV doses, and doses received by critical structures. Group one: CF ranged from 8.1 to 8.7, NN from 30 to 40, NS from 120 to 155 and BT from 20 to 23 minutes; group two: CF from 4.7 to 8.5, NN from 15 to 19, NS from 82 to 141 and BT from 18 to 24 minutes; and group three: CF from 7.9 to 10, NN from 47 to 49, NS from 110 to 113 and BT from 20 to 22 minutes. Conclusions: Delivery time is longer for the CK M6 than for the Varian linac (7.8 to 13.7 minutes). Further investigation will be necessary to determine if a PTV reduction from the tracking feature will shorten the delivery time without decreasing plan quality.

  1. Adjuvant and Definitive Radiotherapy for Adrenocortical Carcinoma

    SciTech Connect

    Sabolch, Aaron; Feng, Mary; Griffith, Kent; Hammer, Gary; Doherty, Gerard; Ben-Josef, Edgar

    2011-08-01

    Purpose: To evaluate the impact of both adjuvant and definitive radiotherapy on local control of adrenocortical carcinoma. Methods and Materials: Outcomes were analyzed from 58 patients with 64 instances of treatment for adrenocortical carcinoma at the University of Michigan's Multidisciplinary Adrenal Cancer Clinic. Thirty-seven of these instances were for primary disease, whereas the remaining 27 were for recurrent disease. Thirty-eight of the treatment regimens involved surgery alone, 10 surgery plus adjuvant radiotherapy, and 16 definitive radiotherapy for unresectable disease. The effects of patient, tumor, and treatment factors were modeled simultaneously using multiple variable Cox proportional hazards regression for associations with local recurrence, distant recurrence, and overall survival. Results: Local failure occurred in 16 of the 38 instances that involved surgery alone, in 2 of the 10 that consisted of surgery plus adjuvant radiotherapy, and in 1 instance of definitive radiotherapy. Lack of radiotherapy use was associated with 4.7 times the risk of local failure compared with treatment regimens that involved radiotherapy (95% confidence interval, 1.2-19.0; p = 0.030). Conclusions: Radiotherapy seems to significantly lower the risk of local recurrence/progression in patients with adrenocortical carcinoma. Adjuvant radiotherapy should be strongly considered after surgical resection.

  2. Radiotherapy in patients with connective tissue diseases.

    PubMed

    Giaj-Levra, Niccolò; Sciascia, Savino; Fiorentino, Alba; Fersino, Sergio; Mazzola, Rosario; Ricchetti, Francesco; Roccatello, Dario; Alongi, Filippo

    2016-03-01

    The decision to offer radiotherapy in patients with connective tissue diseases continues to be challenging. Radiotherapy might trigger the onset of connective tissue diseases by increasing the expression of self-antigens, diminishing regulatory T-cell activity, and activating effectors of innate immunity (dendritic cells) through Toll-like receptor-dependent mechanisms, all of which could potentially lead to breaks of immune tolerance. This potential risk has raised some debate among radiation oncologists about whether patients with connective tissue diseases can tolerate radiation as well as people without connective tissue diseases. Because the number of patients with cancer and connective tissue diseases needing radiotherapy will probably increase due to improvements in medical treatment and longer life expectancy, the issue of interactions between radiotherapy and connective tissue diseases needs to be clearer. In this Review, we discuss available data and evidence for patients with connective tissue diseases treated with radiotherapy.

  3. Management of radiotherapy-induced skin reactions.

    PubMed

    Trueman, Ellen

    2015-04-01

    Radiotherapy is a highly effective cancer treatment that not only offers cure but also excellent palliation of disease related symptoms and complications. Although radiotherapy is primarily an outpatient treatment, delivered within specialist centres, a diverse range of health professionals may be involved in the treatment pathway before, during and after treatment. Radiotherapy can, and does, make a significant contribution to improving a patient's wellbeing through effective symptom management. However, treatment-related side-effects do occur, with an acute skin reaction being one of the most common. It is imperative that radiotherapy-induced skin reactions are correctly assessed and appropriately managed in promoting patient comfort, treatment compliance and enhanced quality of life. This article describes how the use of a recognised assessment tool and evidence-based guidelines can facilitate consistent, high-quality care in the management of radiotherapy-induced skin reactions.

  4. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, Kevin M.; Doyle, Barney L.

    1996-01-01

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue.

  5. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, K.M.; Doyle, B.L.

    1996-08-20

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue. 25 figs.

  6. [Current status and perspectives of radiotherapy for esophageal cancer].

    PubMed

    Wu, S X; Wang, L H

    2016-09-23

    Esophageal cancer is one of the most common cancers in China. More than 80% of esophageal cancer patients are diagnosed at a late stage and are not eligible for surgery. Radiotherapy is one of the most important modalities in esophageal cancer treatment. Here we reviewed the advances in esophageal cancer radiotherapy and radiotherapy-based combined-modality therapy, such as optimization of radiation dose and target volume, application of precise radiotherapy technique and the integration of radiotherapy with chemotherapy and targeted therapy.

  7. [Conformal radiotherapy of brain tumors].

    PubMed

    Haie-Meder, C; Beaudré, A; Breton, C; Biron, B; Cordova, A; Dubray, B; Mazeron, J J

    1999-01-01

    Conformal irradiation of brain tumours is based on the three-dimensional reconstruction of the targeted volumes and at-risk organ images, the three-dimensional calculation of the dose distribution and a treatment device (immobilisation, beam energy, collimation, etc.) adapted to the high precision required by the procedure. Each step requires an appropriate methodology and a quality insurance program. Specific difficulties in brain tumour management are related to GTV and CTV definition depending upon the histological type, the quality of the surgical resection and the medical team. Clinical studies have reported dose escalation trials, mostly in high-grade gliomas and tumours at the base of the skull. Clinical data are now providing a better knowledge of the tolerance of normal tissues. As for small tumours, the implementation of beam intensity modulation is likely to narrow the gap between conformal and stereotaxic radiotherapy. PMID:10572510

  8. [Radiotherapy of benign intracranial tumors].

    PubMed

    Delannes, M; Latorzeff, I; Chand, M E; Huchet, A; Dupin, C; Colin, P

    2016-09-01

    Most of the benign intracranial tumors are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumors. Some of them grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumors are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumor, or a local relapse. Indications have to be discussed in polydisciplinary meetings, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumors, are commonly realized, to avoid as much a possible the occurrence of late side effects. PMID:27523417

  9. [Radiotherapy of carcinoma of the salivary glands].

    PubMed

    Servagi-Vernat, S; Tochet, F

    2016-09-01

    Indication, doses, and technique of radiotherapy for salivary glands carcinoma are presented, and the contribution of neutrons and carbon ions. The recommendations for delineation of the target volumes and organs at risk are detailed. PMID:27521038

  10. Imaging Instrumentation and Techniques for Precision Radiotherapy

    NASA Astrophysics Data System (ADS)

    Parodi, Katia; Parodi, Katia; Thieke, Christian; Thieke, Christian

    Over the last decade, several technological advances have considerably improved the achievable precision of dose delivery in radiation therapy. Clinical exploitation of the superior tumor-dose conformality offered by modern radiotherapy techniques like intensity-modulated radiotherapy and ion beam therapy requires morphological and functional assessment of the tumor during the entire therapy chain from treatment planning to beam application and treatment response evaluation. This chapter will address the main rationale and role of imaging in state-of-the-art external beam radiotherapy. Moreover, it will present the status of novel imaging instrumentation and techniques being nowadays introduced in clinical use or still under development for image guidance and, ultimately, dose guidance of precision radiotherapy.

  11. Historical aspects of heavy ion radiotherapy

    SciTech Connect

    Raju, M.R.

    1995-03-01

    This paper presents historical developments of heavy-ion radiotherapy including discussion of HILAC and HIMAC and discussion of cooperation between Japan and the United States, along with personal reflections.

  12. Heavy particle radiotherapy: prospects and pitfalls

    SciTech Connect

    Faju, M.R.

    1980-01-01

    The use of heavy particles in radiotherapy of tumor volumes is examined. Particles considered are protons, helium ions, heavy ions, negative pions, and fast neutrons. Advantages and disadvantages are discussed. (ACR)

  13. [Conformal radiotherapy for vertebral bone metastasis].

    PubMed

    Faivre, J C; Py, J F; Vogin, G; Martinage, G; Salleron, J; Royer, P; Grandgirard, N; Pasquier, D; Thureau, S

    2016-10-01

    Analgesic external beam radiation therapy is a standard of care for patients with uncomplicated painful bone metastases and/or prevention of bone complications. In case of fracture risk, radiation therapy is performed after surgery in a consolidation of an analgesic purpose and stabilizing osteosynthesis. Radiotherapy is mandatory after vertebroplasty or kyphoplasty. Spinal cord compression - the only emergency in radiation therapy - is indicated postoperatively either exclusively for non surgical indication. Analgesic re-irradiation is possible in the case of insufficient response or recurrent pain after radiotherapy. Metabolic radiation, bisphosphonates or denosumab do not dissuade external radiation therapy for pain relief. Systemic oncological treatments can be suspended with a period of wash out given the risk of radiosensitization or recall phenomenon. Better yet, the intensity modulated radiotherapy and stereotactic radiotherapy can be part of a curative strategy for oligometastatic patients and suggest new treatment prospects. PMID:27614498

  14. Efficacy of radiotherapy in optic gliomas.

    PubMed

    Gould, R J; Hilal, S K; Chutorian, A M

    1987-01-01

    Twenty-five children with optic gliomas were evaluated over a seven year period by sequential computed axial tomography in order to determine the efficacy of radiotherapy as a treatment modality. Indices of tumor progression or regression included both size and contrast enhancement characteristics. Twenty of 25 patients followed during this period received radiotherapy. Of these patients, ten had tumor regression, nine were stable, and one was worse. This result contrasts with five untreated patients, four of whom had tumor progression and one who was stable (x2 = 18.37, p less than .001). One of the children with tumor progression later received radiotherapy and demonstrated marked tumor regression. Of the 18 treated patients who could be tested reliably, visual function and/or regression occurred in seven children. None of the untreated patients improved. There were no definite complications of radiotherapy in this small group.

  15. Radiotherapy in the treatment of vertebral hemangiomas

    SciTech Connect

    Faria, S.L.; Schlupp, W.R.; Chiminazzo, H. Jr.

    1985-02-01

    Symptomatic vertebral hemangiomas are not common. Although radiotherapy has been used as treatment, the data are sparse concerning total dose, fractionation and results. The authors report nine patients with vertebral hemangioma treated with 3000-4000 rad, 200 rad/day, 5 fractions per week, followed from 6 to 62 months. Seventy-seven percent had complete or almost complete disappearance of the symptoms. Radiotherapy schedules are discussed.

  16. Blisters - an unusual effect during radiotherapy.

    PubMed

    Höller, U; Schubert, T; Budach, V; Trefzer, U; Beyer, M

    2013-11-01

    The skin reaction to radiation is regularly monitored in order to detect enhanced radiosensitivity of the patient, unexpected interactions (e.g. with drugs) or any inadvertent overdosage. It is important to distinguish secondary disease from radiation reaction to provide adequate treatment and to avoid unnecessary discontinuation of radiotherapy. A case of bullous eruption or blisters during radiotherapy of the breast is presented. Differential diagnoses bullous pemphigoid, pemphigus vulgaris, and bullous impetigo are discussed and treatment described. PMID:24158604

  17. Evaluation of the peripheral dose in stereotactic radiotherapy and radiosurgery treatments

    SciTech Connect

    Di Betta, Erika; Fariselli, Laura; Bergantin, Achille; Locatelli, Federica; Del Vecchio, Antonella; Broggi, Sara; Fumagalli, Maria Luisa

    2010-07-15

    Purpose: The main purpose of this work was to compare peripheral doses absorbed during stereotactic treatment of a brain lesion delivered using different devices. These data were used to estimate the risk of stochastic effects. Methods: Treatment plans were created for an anthropomorphic phantom and delivered using a LINAC with stereotactic cones and a multileaf collimator, a CyberKnife system (before and after a supplemental shielding was applied), a TomoTherapy system, and a Gamma Knife unit. For each treatment, 5 Gy were prescribed to the target. Measurements were performed with thermoluminescent dosimeters inserted roughly in the position of the thyroid, sternum, upper lung, lower lung, and gonads. Results: Mean doses ranged from of 4.1 (Gamma Knife) to 62.8 mGy (LINAC with cones) in the thyroid, from 2.3 (TomoTherapy) to 30 mGy (preshielding CyberKnife) in the sternum, from 1.7 (TomoTherapy) to 20 mGy (preshielding CyberKnife) in the upper part of the lungs, from 0.98 (Gamma Knife) to 15 mGy (preshielding CyberKnife) in the lower part of the lungs, and between 0.3 (Gamma Knife) and 10 mGy (preshielding CyberKnife) in the gonads. Conclusions: The peripheral dose absorbed in the sites of interest with a 5 Gy fraction is low. Although the risk of adverse side effects calculated for 20 Gy delivered in 5 Gy fractions is negligible, in the interest of optimum patient radioprotection, further studies are needed to determine the weight of each contributor to the peripheral dose.

  18. Radiotherapy for Vestibular Schwannomas: A Critical Review

    SciTech Connect

    Murphy, Erin S.; Suh, John H.

    2011-03-15

    Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation to >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

  19. Adapting radiotherapy to hypoxic tumours

    NASA Astrophysics Data System (ADS)

    Malinen, Eirik; Søvik, Åste; Hristov, Dimitre; Bruland, Øyvind S.; Rune Olsen, Dag

    2006-10-01

    In the current work, the concepts of biologically adapted radiotherapy of hypoxic tumours in a framework encompassing functional tumour imaging, tumour control predictions, inverse treatment planning and intensity modulated radiotherapy (IMRT) were presented. Dynamic contrast enhanced magnetic resonance imaging (DCEMRI) of a spontaneous sarcoma in the nasal region of a dog was employed. The tracer concentration in the tumour was assumed related to the oxygen tension and compared to Eppendorf histograph measurements. Based on the pO2-related images derived from the MR analysis, the tumour was divided into four compartments by a segmentation procedure. DICOM structure sets for IMRT planning could be derived thereof. In order to display the possible advantages of non-uniform tumour doses, dose redistribution among the four tumour compartments was introduced. The dose redistribution was constrained by keeping the average dose to the tumour equal to a conventional target dose. The compartmental doses yielding optimum tumour control probability (TCP) were used as input in an inverse planning system, where the planning basis was the pO2-related tumour images from the MR analysis. Uniform (conventional) and non-uniform IMRT plans were scored both physically and biologically. The consequences of random and systematic errors in the compartmental images were evaluated. The normalized frequency distributions of the tracer concentration and the pO2 Eppendorf measurements were not significantly different. 28% of the tumour had, according to the MR analysis, pO2 values of less than 5 mm Hg. The optimum TCP following a non-uniform dose prescription was about four times higher than that following a uniform dose prescription. The non-uniform IMRT dose distribution resulting from the inverse planning gave a three times higher TCP than that of the uniform distribution. The TCP and the dose-based plan quality depended on IMRT parameters defined in the inverse planning procedure (fields

  20. Radiotherapy Treatment Planning for Testicular Seminoma

    SciTech Connect

    Wilder, Richard B.; Buyyounouski, Mark K.; Efstathiou, Jason A.; Beard, Clair J.

    2012-07-15

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

  1. [Needs and financing of radiotherapy in France and Europe].

    PubMed

    Defourny, N; Lievens, Y

    2016-10-01

    Access to high-quality and safe radiotherapy is a prerequisite to assure optimal oncology care in a multidisciplinary environment. In view of supporting long-term radiotherapy planning, actual and predicted radiotherapy needs should be put in context of the nowadays' available resources. The present article reviews the existing data on radiotherapy resources and needs, along with the prevailing reimbursement systems in the different European countries, with a specific emphasis on France. It describes potential incentives of different financing systems on clinical practice and highlights how knowledge of the cost of radiotherapy treatments, by indication and technique, is essential to support correct reimbursement, hence access to radiotherapy. It is expected that such data will help national professional and scientific radiotherapy societies across Europe in their negotiations with policy makers, with the ultimate aim to make radiotherapy accessible to all cancer patients who need it, now and in the decades to come.

  2. [Needs and financing of radiotherapy in France and Europe].

    PubMed

    Defourny, N; Lievens, Y

    2016-10-01

    Access to high-quality and safe radiotherapy is a prerequisite to assure optimal oncology care in a multidisciplinary environment. In view of supporting long-term radiotherapy planning, actual and predicted radiotherapy needs should be put in context of the nowadays' available resources. The present article reviews the existing data on radiotherapy resources and needs, along with the prevailing reimbursement systems in the different European countries, with a specific emphasis on France. It describes potential incentives of different financing systems on clinical practice and highlights how knowledge of the cost of radiotherapy treatments, by indication and technique, is essential to support correct reimbursement, hence access to radiotherapy. It is expected that such data will help national professional and scientific radiotherapy societies across Europe in their negotiations with policy makers, with the ultimate aim to make radiotherapy accessible to all cancer patients who need it, now and in the decades to come. PMID:27599682

  3. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2014-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  4. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2013-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  5. [Image-guided radiotherapy and partial delegation to radiotherapy technicians: Clermont-Ferrand experience].

    PubMed

    Loos, G; Moreau, J; Miroir, J; Benhaïm, C; Biau, J; Caillé, C; Bellière, A; Lapeyre, M

    2013-10-01

    The various image-guided radiotherapy techniques raise the question of how to achieve the control of patient positioning before irradiation session and sharing of tasks between radiation oncologists and radiotherapy technicians. We have put in place procedures and operating methods to make a partial delegation of tasks to radiotherapy technicians and secure the process in three situations: control by orthogonal kV imaging (kV-kV) of bony landmarks, control by kV-kV imaging of intraprostatic fiducial goldmarkers and control by cone beam CT (CBCT) imaging for prostate cancer. Significant medical overtime is required to control these three IGRT techniques. Because of their competence in imaging, these daily controls can be delegated to radiotherapy technicians. However, to secure the process, initial training and regular evaluation are essential. The analysis of the comparison of the use of kV/kV on bone structures allowed us to achieve a partial delegation of control to radiotherapy technicians. Controlling the positioning of the prostate through the use and automatic registration of fiducial goldmarkers allows better tracking of the prostate and can be easily delegated to radiotherapy technicians. The analysis of the use of daily cone beam CT for patients treated with intensity modulated irradiation is underway, and a comparison of practices between radiotherapy technicians and radiation oncologists is ongoing to know if a partial delegation of this control is possible. PMID:24011600

  6. A dose comparison of proton radiotherapy and photon radiotherapy for pediatric brain tumor

    NASA Astrophysics Data System (ADS)

    Kim, S. Y.; Cho, J. H.

    2014-12-01

    The purpose of this study was to investigate the effectiveness of photon radiotherapy and to compare the dose of treatment planning between proton radiotherapy and 3D conformal radiation therapy (3D-CRT) for pediatric brain tumor patients. This study was conducted in five pediatric brain tumor patients who underwent craniospinal irradiation treatment from October 2013 to April 2014 in the hospital. The study compared organs at risk (OARs) by assessing the dose distribution of normal tissue from the proton plan and 3D-CRT. Furthermore, this study assessed the treatment plans by looking at the homogeneity index (HI) and conformity index (CI). As a result, the study revealed OARs due to the small volume proton radiotherapy dose distribution in the normal tissue. Also, by comparing HI and CI between the 3D-CRT and proton radiotherapy plan, the study found that the dose of proton radiotherapy plan was homogenized. When conducting 3D-CRT and proton radiotherapy in a dose-volume histogram comparison, the dose of distribution turned out to be low. Consequently, proton radiotherapy is used for protecting the normal tissue, and is used in tumor tissue as a homogenized dose for effective treatment.

  7. Time delays in gated radiotherapy.

    PubMed

    Smith, Wendy L; Becker, Nathan

    2009-07-28

    In gated radiotherapy, the accuracy of treatment delivery is determined by the accuracy with which both the imaging and treatment beams are gated. If the time delays (the time between the target entering/leaving the gated region and the first/last image acquired or treatment beam on/off) for the imaging and treatment systems are in the opposite directions, they may increase the required internal target volume (ITV) margin, above that indicated by the tolerance for either system measured individually. We measured a gating system's time delay on 3 fluoroscopy systems, and 3 linear accelerator treatment beams, using a motion phantom of known geometry, varying gating type (amplitude vs. phase), beam energy, dose rate, and period. The average beam on imaging time delays were -0.04 +/- 0.05 s (amplitude, 1 SD), -0.11 +/- 0.04 s (phase); while the average beam off imaging time delays were -0.18 +/- 0.08 s (amplitude) and -0.15 +/- 0.04 s (phase). The average beam on treatment time delays were 0.09 +/- 0.02 s (amplitude, 1 SD), 0.10 +/- 0.03 s (phase); while the average beam off time delays for treatment beams were 0.08 +/- 0.02 s (amplitude) and 0.07 +/- 0.02 s (phase). The negative value indicates the images were acquired early, and the positive values show the treatment beam was triggered late. We present a technique for calculating the margin necessary to account for time delays and found that the difference between the imaging and treatment time delays required a significant increase in the ITV margin in the direction of tumor motion at the gated level.

  8. Operations experience at the Bevalac radiotherapy facility

    SciTech Connect

    Alonso, J.R.; Criswell, T.L.; Howard, J.; Chu, W.T.; Singh, R.P.; Geller, D.; Nyman, M.

    1981-03-01

    During the first years of Bevalac operation the biomedical effort concentrated on radiobiology work, laying the foundation for patient radiotherapy. A dedicated radiotherapy area was created in 1978, and in 1979 full-scale patient treatment was begun. As of now over 500 treatments with carbon, neon and argon beams have been delivered to about 50 patients, some as boosts from other modalities and some as complete heavy ion treatments. Up to 12 patients per day have been treated in this facility. Continuing efforts in refining techniques and operating procedures are increasing efficiency and accuracy of treatments, and are contributing to the alleviation of scheduling difficulties caused by the unique requirements of radiotherapy with human patients.

  9. Radiotherapy enhances the toxicity of aminoglutethimide

    SciTech Connect

    Vanek, N.; Hortobagyi, G.N.; Buzdar, A.U. )

    1990-01-01

    We report a case of radiotherapy-enhanced aminoglutethimide skin toxicity in a patient with metastatic breast cancer. This patient was started on aminoglutethimide 6 days prior to radiation therapy, for painful bone metastasis. On day 7 of radiation therapy, she developed an extensive erythematous maculopapular rash over her face, trunk, and extremities. The rash was confluent over the radiation ports, both anteriorly and posteriorly. Aminoglutethimide was discontinued until completion of radiotherapy, and the rash resolved. Concomitant irradiation apparently enhanced the skin toxicity of aminoglutethimide or possibly aminoglutethimide had a radiosensitizing role in this patient.

  10. Pelvic radiotherapy and sexual function in women

    PubMed Central

    Froeding, Ligita Paskeviciute

    2015-01-01

    Background During the past decade there has been considerable progress in developing new radiation methods for cancer treatment. Pelvic radiotherapy constitutes the primary or (neo) adjuvant treatment of many pelvic cancers e.g., locally advanced cervical and rectal cancer. There is an increasing focus on late effects and an increasing awareness that patient reported outcomes (PROs) i.e., patient assessment of physical, social, psychological, and sexual functioning provides the most valid information on the effects of cancer treatment. Following cure of cancer allow survivors focus on quality of life (QOL) issues; sexual functioning has proved to be one of the most important aspects of concern in long-term survivors. Methods An updated literature search in PubMed was performed on pelvic radiotherapy and female sexual functioning/dysfunction. Studies on gynaecological, urological and gastrointestinal cancers were included. The focus was on the period from 2010 to 2014, on studies using PROs, on potential randomized controlled trials (RCTs) where female sexual dysfunction (FSD) at least constituted a secondary outcome, and on studies reporting from modern radiotherapy modalities. Results The literature search revealed a few RCTs with FSD evaluated as a PRO and being a secondary outcome measure in endometrial and in rectal cancer patients. Very limited information could be extracted regarding FSD in bladder, vulva, and anal cancer patients. The literature before and after 2010 confirms that pelvic radiotherapy, independent on modality, increases the risk significantly for FSD both compared to data from age-matched healthy control women and compared to data on patients treated by surgery only. There was only very limited data available on modern radiotherapy modalities. These are awaited during the next five years. Several newer studies confirm that health care professionals are still reluctant to discuss treatment induced sexual dysfunction with patients. Conclusions

  11. SU-E-T-604: Penumbra Characteristics of a New InCiseâ„¢ Multileaf Collimator of CyberKnife M6â„¢ System

    SciTech Connect

    Hwang, M; Jang, S; Ozhasoglu, C; Lalonde, R; Heron, D; Huq, M

    2015-06-15

    Purpose: The InCise™ Multileaf Collimator (MLC) of CyberKnife M6™ System has been released recently. The purpose of this study was to explore the dosimetric characteristics of the new MLC. In particular, the penumbra characteristics of MLC fields at varying locations are evaluated. Methods: EBT3-based film measurements were performed with varying MLC fields ranging from 7.5 mm to 27.5 mm. Seventeen regions of interests (ROIs) were identified for irradiation. These are regions located at the central area (denoted as reference field), at the left/right edge areas of reference open field, at an intermediate location between central and edge area. Single beam treatment plans were designed by using the MultiPlan and was delivered using the Blue Phantom. Gafchromic films were irradiated at 1.5 cm depth in the Blue Phantom and analyzed using the Film Pro software. Variation of maximum dose, penumbra of MLC-defined fields, and symmetry/flatness were calculated as a function of locations of MLC fields. Results: The InCise™ MLC System showed relatively consistent dose distribution and penumbra size with varying locations of MLC fields. The measured maximum dose varied within 5 % at different locations compared to that at the central location and agreed with the calculated data well within 2%. The measured penumbrae were in the range of 2.9 mm and 3.7 mm and were relatively consistent regardless of locations. However, dose profiles in the out-of-field and in-field regions varied with locations and field sizes. Strong variation was seen for all fields located at 55 mm away from the central field. The MLC leakage map showed that the leakage is dependent on position. Conclusion: The size of penumbra and normalized maximum dose for MLC-defined fields were consistent in different regions of MLC. However, dose profiles in the out-field region varied with locations and field sizes.

  12. Radiotherapy in the management of early breast cancer

    SciTech Connect

    Wang, Wei

    2013-03-15

    Radiotherapy is an indispensible part of the management of all stages of breast cancer. In this article, the common indications for radiotherapy in the management of early breast cancer (stages 0, I, and II) are reviewed, including whole-breast radiotherapy as part of breast-conserving treatment for early invasive breast cancer and pre-invasive disease of ductal carcinoma in situ, post-mastectomy radiotherapy, locoregional radiotherapy, and partial breast irradiation. Key clinical studies that underpin our current practice are discussed briefly.

  13. Clinical development of new drug-radiotherapy combinations.

    PubMed

    Sharma, Ricky A; Plummer, Ruth; Stock, Julie K; Greenhalgh, Tessa A; Ataman, Ozlem; Kelly, Stephen; Clay, Robert; Adams, Richard A; Baird, Richard D; Billingham, Lucinda; Brown, Sarah R; Buckland, Sean; Bulbeck, Helen; Chalmers, Anthony J; Clack, Glen; Cranston, Aaron N; Damstrup, Lars; Ferraldeschi, Roberta; Forster, Martin D; Golec, Julian; Hagan, Russell M; Hall, Emma; Hanauske, Axel-R; Harrington, Kevin J; Haswell, Tom; Hawkins, Maria A; Illidge, Tim; Jones, Hazel; Kennedy, Andrew S; McDonald, Fiona; Melcher, Thorsten; O'Connor, James P B; Pollard, John R; Saunders, Mark P; Sebag-Montefiore, David; Smitt, Melanie; Staffurth, John; Stratford, Ian J; Wedge, Stephen R

    2016-10-01

    In countries with the best cancer outcomes, approximately 60% of patients receive radiotherapy as part of their treatment, which is one of the most cost-effective cancer treatments. Notably, around 40% of cancer cures include the use of radiotherapy, either as a single modality or combined with other treatments. Radiotherapy can provide enormous benefit to patients with cancer. In the past decade, significant technical advances, such as image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic radiotherapy, and proton therapy enable higher doses of radiotherapy to be delivered to the tumour with significantly lower doses to normal surrounding tissues. However, apart from the combination of traditional cytotoxic chemotherapy with radiotherapy, little progress has been made in identifying and defining optimal targeted therapy and radiotherapy combinations to improve the efficacy of cancer treatment. The National Cancer Research Institute Clinical and Translational Radiotherapy Research Working Group (CTRad) formed a Joint Working Group with representatives from academia, industry, patient groups and regulatory bodies to address this lack of progress and to publish recommendations for future clinical research. Herein, we highlight the Working Group's consensus recommendations to increase the number of novel drugs being successfully registered in combination with radiotherapy to improve clinical outcomes for patients with cancer. PMID:27245279

  14. Breast Cancer Patients’ Experience of External-Beam Radiotherapy

    PubMed Central

    Schnur, Julie B.; Ouellette, Suzanne C.; Bovbjerg, Dana H.; Montgomery, Guy H.

    2013-01-01

    Radiotherapy is a critical component of treatment for the majority of women with breast cancer, particularly those who receive breast conserving surgery. Although medically beneficial, radiotherapy can take a physical and psychological toll on patients. However, little is known about the specific thoughts and feelings experienced by women undergoing breast cancer radiotherapy. Therefore, the study aim was to use qualitative research methods to develop an understanding of these thoughts and feelings based on 180 diary entries, completed during radiotherapy by 15 women with Stage 0-III breast cancer. Thematic analysis identified four primary participant concerns: (a) a preoccupation with time; (b) fantasies (both optimistic and pessimistic) about life following radiotherapy; (c) the toll their side-effect experience takes on their self-esteem; and (d) feeling mystified by radiotherapy. These themes are consistent with previous literature on illness and identity. These findings have implications for the treatment and care of women undergoing breast cancer radiotherapy. PMID:19380502

  15. Results of radiotherapy for Peyronie's disease

    SciTech Connect

    Niewald, Marcus . E-mail: ramnie@uniklinikum-saarland.de; Wenzlawowicz, Knut v.; Fleckenstein, Jochen; Wisser, Lothar; Derouet, Harry; Ruebe, Christian

    2006-01-01

    Purpose: To retrospectively review the results of radiotherapy for Peyronie's disease. Patients and Methods: In the time interval 1983-2000, 154 patients in our clinic were irradiated for Peyronie's disease. Of those, 101 had at least one complete follow-up data set and are the subject of this study. In the majority of patients, penis deviation was between 30 and 50{sup o}, there were one or two indurated foci with a diameter between 5 and 15 mm. Pain was recorded in 48/92 patients. Seventy-two of the 101 patients received radiotherapy with a total dose of 30 Gy, and 25 received 36 Gy in daily fractions of 2.0 Gy. The remaining patients received the following dosage: 34 Gy (1 patient), 38-40 Gy (3 patients). Mean duration of follow-up was 5 years. Results: The best results ever at any time during follow-up were an improvement of deviation in 47%, reduction of number of foci in 32%, reduction of size of foci in 49%, and less induration in 52%. Approximately 50% reported pain relief after radiotherapy. There were 28 patients with mild acute dermatitis and only 4 patients with mild urethritis. There were no long-term side effects. Conclusion: Our results compare well with those of other studies in the literature. In our patient cohort, radiotherapy was an effective therapy option with only very rare and mild side effects.

  16. Radiotherapy reduces sialorrhea in amyotrophic lateral sclerosis.

    PubMed

    Neppelberg, E; Haugen, D F; Thorsen, L; Tysnes, O-B

    2007-12-01

    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. Sialorrhea is a frequent problem in ALS patients with bulbar symptoms, because of progressive weakness of oral, lingual and pharyngeal muscles. This prospective study aimed to investigate the putative effect of palliative single-dose radiotherapy on problematic sialorrhea in patients with ALS. Twenty patients with ALS and problematic drooling were included; 14 were given radiotherapy with a single fraction of 7.5 Grey (Gy). Five patients were treated with botulinum toxin A (BTX-A) injections (20 U) into the parotid glands; two of these were later given radiotherapy. Symptom assessment, clinical examination and measurements of salivary flow (ml/min) were performed before and after treatment (1-2 weeks, 3 months). Salivary secretion was significantly reduced after radiation treatment, with a mean reduction of 60% (1 week) and 51% (2 weeks). Three months post-treatment, 21% reduction of the salivary secretion was observed compared with salivation before treatment. Mean salivary flow was not reduced after BTX-A treatment in five patients. No serious side-effects were observed with either of the two treatment modalities. Single-dose radiotherapy (7.5 Gy) significantly reduces sialorrhea and is an effective and safe palliative treatment in patients with ALS.

  17. Prostate cancer radiotherapy 2002: the way forward.

    PubMed

    Lukka, Himu; Pickles, Tom; Morton, Gerard; Catton, Charles; Souhami, Luis; Warde, Padraig

    2005-02-01

    In November 2000, the GU Radiation Oncologists of Canada had their first meeting, "Controversies in prostate cancer radiotherapy: consensus development". The success of this meeting prompted a second meeting, held in December 2002 to discuss "The Way Forward" in prostate radiotherapy. Radiation oncologists from across Canada were brought together and integrated with key opinion leaders in prostate cancer treatment from throughout North America. The group debated current controversies including: intensity modulated radiotherapy (IMRT), external beam hypofractionation, high dose-rate brachytherapy, and hormone therapy in the management of prostate cancer. The meeting also sought to identify and prioritize clinical trial opportunities and to highlight steps required to achieve these research goals. In summary, advances involving IMRT have enabled the use of higher radiation doses without increasing morbidity. With renewed interest in hypofractionated radiation schedules, the value of hypofractionation using IMRT was discussed and initial results from ongoing clinical trials were presented. The emerging role for high dose-rate brachytherapy in higher risk patients was also discussed. Based on existing preliminary evidence the group expressed enthusiasm for further investigation of the role for brachytherapy in intermediate to high-risk patients. Despite significant advances in radiotherapy, hormone therapy continues to play an important role in prostate cancer treatment for patients with intermediate and high-risk disease. Although evidence supports the effectiveness of hormone therapy, the optimal timing, and duration of hormonal treatment are unclear. Results from ongoing clinical trials will provide insight into these questions and will assist in the design of future clinical trials.

  18. The Role of Radiotherapy in Acromegaly.

    PubMed

    Hannon, Mark J; Barkan, Ariel L; Drake, William M

    2016-01-01

    Radiotherapy has, historically, played a central role in the management of acromegaly, and the last 30 years have seen substantial improvements in the technology used in the delivery of radiation therapy. More recently, the introduction of highly targeted radiotherapy, or 'radiosurgery', has further increased the therapeutic options available in the management of secretory pituitary tumors. Despite these developments, improvements in primary surgical outcomes, an increase in the range and effectiveness of medical therapy options, and long-term safety concerns have combined to dictate that, although still deployed in selected cases, the use of radiotherapy in the management of acromegaly has declined steadily over the past 2 decades. In this article, we review some of the main studies that have documented the efficacy of pituitary radiotherapy on growth hormone hypersecretion and summarize the data around its potential deleterious effects, including hypopituitarism, cranial nerve damage, and the development of radiation-related intracerebral tumors. We also give practical recommendations to guide its future use in patients with acromegaly, generally, as a third-line intervention after neurosurgical intervention in combination with various medical therapy options.

  19. Technical advances in external radiotherapy for hepatocellular carcinoma

    PubMed Central

    Park, Shin-Hyung; Kim, Jae-Chul; Kang, Min Kyu

    2016-01-01

    Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma (HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy (IMRT), stereotactic ablative body radiotherapy (SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy. PMID:27621577

  20. Evidence-based estimates of the demand for radiotherapy.

    PubMed

    Delaney, G P; Barton, M B

    2015-02-01

    There are different methods that may be used to estimate the future demand for radiotherapy services in a population ranging from expert opinion through to complex modelling techniques. This manuscript describes the use of evidence-based treatment guidelines to determine indications for radiotherapy. It also uses epidemiological data to estimate the proportion of the population who have attributes that suggest a benefit from radiotherapy in order to calculate the overall proportion of a population of new cases of cancer who appropriately could be recommended to undergo radiotherapy. Evidence-based methods are transparent and adaptable to different populations but require extensive information about the indications for radiotherapy and the proportion of cancer cases with those indications in the population. In 2003 this method produced an estimate that 52.4% of patients with a registered cancer-type had an indication for radiotherapy. The model was updated in 2012 because of changes in cancer incidence, stage distributions and indications for radiotherapy. The new estimate of the optimal radiotherapy utilisation rate was 48.3%. The decrease was due to changes in the relative frequency of cancer types and some changes in indications for radiotherapy. Actual rates of radiotherapy utilisation in most populations still fall well below this benchmark. PMID:25455408

  1. Technical advances in external radiotherapy for hepatocellular carcinoma

    PubMed Central

    Park, Shin-Hyung; Kim, Jae-Chul; Kang, Min Kyu

    2016-01-01

    Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma (HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy (IMRT), stereotactic ablative body radiotherapy (SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy.

  2. Technical advances in external radiotherapy for hepatocellular carcinoma.

    PubMed

    Park, Shin-Hyung; Kim, Jae-Chul; Kang, Min Kyu

    2016-08-28

    Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma (HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy (IMRT), stereotactic ablative body radiotherapy (SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy. PMID:27621577

  3. Adjuvant Radiotherapy with Three-Dimensional Conformal Radiotherapy of Lacrimal Gland Adenoid Cystic Carcinoma

    PubMed Central

    Roshan, Vikas; Mallick, Supriya; Chander, Subhash; Sen, Seema; Chawla, Bhavna

    2015-01-01

    Background & Aim Adenoid cystic carcinoma (ACC) of lacrimal gland is a rare tumour with aggressive behaviour. There is sparse data to address optimum therapy for such tumours. So, the present study was aimed at evaluating the role of adjuvant three dimensional conformal radiotherapy (3D-CRT) in cases of incomplete (R1) resection along with review of literature pertaining to management of lacrimal adenoid cystic carcinoma Materials and Methods We retrospectively reviewed the demographic and treatment data of 10 biopsy proven ACC of lacrimal gland patients, treated from December 2006 to June 2013. They were treated with radiotherapy following surgical resection. Eight patients underwent gross total excision of the tumour mass (enbloc excision) followed by conformal radiotherapy to a dose of 60 Gray/30fractions/ 6 weeks. Two patients with advanced disease were treated with palliative radiotherapy after biopsy. Results The median age was 32 years. There were equal numbers of male and female patients. The median duration of symptoms was 7 months. At a median follow up of 21 months, eight patients had no evidence of disease and had complete tumour response, two patients worsened, and one of the two had systemic failure with bone metastasis. Conclusion Despite a small sample size and short follow, enbloc surgical excision with adjuvant radiotherapy is well tolerated and shows good control in ACC of lacrimal gland. PMID:26557600

  4. [How to maximize skin care during radiotherapy?].

    PubMed

    Fromantin, I; Lesport, G; Le Mée, M

    2015-10-01

    No consensual guidelines exist regarding the management of early effects of radiotherapy. But preventive and curative care strategies could be adapted in the aim to delay erythema, limit complications and improve patients' comfort. Prevention involves encouraging patients to take care of their skin, avoid moisture, frictions, sun exposition and dry soap. When these rules seem insufficient, products (dressings, solution, or cream) could be prescribed, according to the individual risk of each patient. Preventive measures are accentuated when radiodermatitis appears and/or topics indicated for wound healing could be applied. Care (education, dressing, observation) needs a multidisciplinary approach. Improvements of radiotherapy treatments (methods, techniques) have been the most effective evolution on radiodermatitis. PMID:26344433

  5. [Personalized medicine in radiotherapy: practitioners' perception].

    PubMed

    Britel, Manon; Foray, Nicolas; Préau, Marie

    2015-01-01

    This exploratory study was designed to investigate the representations of radiotherapists in relation to personalized medicine. On the basis of current?>' available radiotherapy predictive tests, we tried to understand how these tests could be used in routine radiotherapy practice and in what way this possible change of practices could affect the role of radiotherapists in treatment protocols. In the absence of any available data allowing the construction of a quantitative tool, qualitative data were recorded by individual interviews with radiotherapists. Based on textual data analysis, a second national quantitative phase was conducted using a self-administered questionnaire. Crossover analysis of the two datasets highlighted the interest of radiotherapists in personalized medicine and the use of predictive tests, while indicating certain limitations and concerns in relation to ethical issues related to personalized medicine in oncology and the physician's position. PMID:26752033

  6. Complications of surgery for radiotherapy skin damage

    SciTech Connect

    Rudolph, R.

    1982-08-01

    Complications of modern surgery for radiotherapy skin damage reviewed in 28 patients who had 42 operations. Thin split-thickness skin grafts for ulcer treatment had a 100 percent complication rate, defined as the need for further surgery. Local flaps, whether delayed or not, also had a high rate of complications. Myocutaneous flaps for ulcers had a 43 percent complication rate, with viable flaps lifting off radiated wound beds. Only myocutaneous flaps for breast reconstruction and omental flaps with skin grafts and Marlex mesh had no complications. The deeper tissue penetration of modern radiotherapy techniques may make skin grafts and flaps less useful. In reconstruction of radiation ulcers, omental flaps and myocutaneous flaps are especially useful, particularly if the radiation damage can be fully excised. The pull of gravity appears detrimental to myocutaneous flap healing and, if possible, should be avoided by flap design.

  7. Radiotherapy of unicentric mediastinal Castleman's disease

    PubMed Central

    Li, Yue-Min; Liu, Peng-Hui; Zhang, Yu-Hai; Xia, Huo-Sheng; Li, Liang-Liang; Qu, Yi-Mei; Wu, Yong; Han, Shou-Yun; Liao, Guo-Qing; Pu, Yong-Dong

    2011-01-01

    Castleman's disease is a slowly progressive and rare lymphoproliferative disorder. Here, we report a 55-year-old woman with superior mediastinal Castleman's disease being misdiagnosed for a long term. We found a 4.3 cm mass localized in the superior mediastinum accompanied with severe clinical symptoms. The patient underwent an exploratory laparotomy, but the mass failed to be totally excised. Pathologic examination revealed a mediastinal mass of Castleman's disease. After radiotherapy of 30 Gy by 15 fractions, the patient no longer presented previous symptoms. At 3 months after radiotherapy of 60 Gy by 30 fractions, Computed tomography of the chest showed significantly smaller mass, indicating partial remission. Upon a 10-month follow-up, the patient was alive and free of symptoms. PMID:21527068

  8. Clinical Applications for Diffusion MRI in Radiotherapy

    PubMed Central

    Tsien, Christina; Cao, Yue; Chenevert, Thomas

    2014-01-01

    In this article, we review the clinical applications of diffusion MR imaging in the radiotherapy treatment of several key clinical sites, including those of the CNS, the head and neck, the prostate and cervix. Diffusion-weighted MRI (DWI) is an imaging technique that is rapidly gaining widespread acceptance due to its ease and wide availability. DWI measures the mobility of water within tissue at the cellular level without the need of any exogenous contrast agent. For radiotherapy treatment planning, DWI improves upon conventional imaging techniques, by better characterization of tumor tissue properties required for tumor grading, diagnosis and target volume delineation. Because diffusion weighted MRI is also a sensitive marker for alterations in tumor cellularity, it has potential clinical applications in the early assessment of treatment response following radiation therapy. PMID:24931097

  9. The efficacy of radiotherapy for vertebral hemangiomas.

    PubMed

    Miszczyk, L; Ficek, K; Trela, K; Spindel, J

    2001-01-01

    Vertebral hemangiomas are benign, slowly growing tumors sometimes causing local pain in the spine and/or neurologic disorders. The present paper includes 14 cases of painful vertebral hemangiomas treated by radiotherapy. All patients were irradiated using standard fractionation scheme with a total dose 20-30 Gy. One month after the treatment complete pain relief was noted in 36% of cases, five months later in 67% of cases, but in the remaining cases partial pain relief was noted. No correlation between treatment outcome and different biological and technical factors was found. No dose-response relationship was noted. The results suggest that anti-inflamatory effect of radiation plays the major role in this kind of treatment and that radiotherapy for vertebral hemangiomas is easy, short and highly effective analgetic treatment modality.

  10. Radiotherapy of nonfunctioning and gonadotroph adenomas.

    PubMed

    Kanner, Andrew A; Corn, Benjamin W; Greenman, Yona

    2009-01-01

    Transsphenoidal surgery is the treatment of choice for NFPA but is seldom curative. The management of patients in whom residual tumor is detected after surgery is not clear-cut. Radiation therapy is effective in controlling tumor mass in the majority of patients, but is associated with long term complications that call for restriction of its use to patients at high risk for tumor growth. New radiation techniques may prove to be safer while retaining the effectiveness of conventional radiotherapy, however longer follow-up is necessary to confirm this assumption. For now, it appears to be safe to withhold radiation and carefully follow patients with small tumor remnants, whereas large remnants from invasive tumors should be considered for radiotherapy. Nevertheless, there are no prospective controlled studies that support this empirical approach. PMID:18286373

  11. Second cancers following radiotherapy for cancer

    SciTech Connect

    Curtis, R.E.

    1997-03-01

    The study of second cancer risk after radiotherapy provides a unique opportunity to study carcinogenesis since large groups of humans are deliberately exposed to substantial doses of radiation in order to cure disease. Detailed radiotherapy records for cancer patients allow precise quantification of organ dose, and population-based cancer registries are frequently available to provide access to large groups of patients who are closely followed for long periods. Moreover, cancer patients treated with surgery alone (no radiation) are frequently available to serve as a non-irradiated comparison group. New information can be provided on relatively insensitive organs, and low dose exposures in the range of scientific interest are received by organs outside the radiation treatment fields. This paper will review several recently completed studies that characterize the risk of radiation-induced second cancers. Emphasis will be given to studies providing new information on the dose-response relationship of radiation-induced leukemia, breast cancer and lung cancer.

  12. Low-Dose Radiotherapy in Indolent Lymphoma

    SciTech Connect

    Rossier, Christine; Schick, Ulrike; Miralbell, Raymond; Mirimanoff, Rene O.; Weber, Damien C.; Ozsahin, Mahmut

    2011-11-01

    Purpose: To assess the response rate, duration of response, and overall survival after low-dose involved-field radiotherapy in patients with recurrent low-grade lymphoma or chronic lymphocytic leukemia (CLL). Methods and Materials: Forty-three (24 women, 19 men) consecutive patients with indolent lymphoma or CLL were treated with a total dose of 4 Gy (2 x 2 Gy) using 6- 18-MV photons. The median age was 73 years (range, 39-88). Radiotherapy was given either after (n = 32; 75%) or before (n = 11; 25%) chemotherapy. The median time from diagnosis was 48 months (range, 1-249). The median follow-up period was 20 months (range, 1-56). Results: The overall response rate was 90%. Twelve patients (28%) had a complete response, 15 (35%) had a partial response, 11 (26%) had stable disease, and 5 (11%) had progressive disease. The median overall survival for patients with a positive response (complete response/partial response/stable disease) was 41 months; for patients with progressive disease it was 6 months (p = 0.001). The median time to in-field progression was 21 months (range, 0-24), and the median time to out-field progression was 8 months (range, 0-40). The 3-year in-field control was 92% in patients with complete response (median was not reached). The median time to in-field progression was 9 months (range, 0.5-24) in patients with partial response and 6 months (range, 0.6-6) in those with stable disease (p < 0.05). Younger age, positive response to radiotherapy, and no previous chemotherapy were the best factors influencing the outcome. Conclusions: Low-dose involved-field radiotherapy is an effective treatment in the management of patients with recurrent low-grade lymphoma or CLL.

  13. Radiotherapy equipment--purchase or lease?

    PubMed

    Nisbet, A; Ward, A

    2001-08-01

    Against a background of increasing demand for radiotherapy equipment, this study was undertaken to investigate options for equipment procurement, in particular to compare purchase with lease. The perceived advantages of lease are that equipment can be acquired within budget and cashflow constraints, with relatively low amounts of cash leaving the NHS in the first year, avoiding the necessity of capitalizing the equipment and providing protection against the risk of obsolescence associated with high technology equipment. The perceived disadvantages of leasing are that the Trust does not own the equipment, leasing can be more expensive in revenue terms, the tender process is extended and there may be lease conditions to be met, which may be costly and/or restrictive. There are also a number of technical considerations involved in the leasing of radiotherapy equipment that influence the financial analysis and practical operation of the radiotherapy service. The technical considerations include servicing and planned preventative maintenance, upgrades, spare parts, subsequent purchase of "add ons", modification of equipment, research and development work, commencement of the lease period, return of equipment at the end of the lease period and negotiations at the end of the lease period. A study from Raigmore Hospital, Inverness is described, which involves the procurement of new, state-of-the-art radiotherapy equipment. This provides an overview of the procurement process, including a summary of the advantages and disadvantages of leasing, with the figures from the financial analysis presented and explained. In addition, a detailed description is given of the technical considerations to be taken into account in the financial analysis and negotiation of any lease contract.

  14. Radiotherapy in the treatment of postoperative chylothorax

    PubMed Central

    2013-01-01

    Background Chylothorax is characterized by the presence of chyle in the pleural cavity. The healing rate of non-operative treatment varies enormously; the maximum success rate in series is 70%. We investigate the efficacy and outcomes of radiotherapy for postoperative chylothorax. Methods Chylothorax was identified based on the quantity and quality of the drainage fluid. Radiation was indicated if the daily chyle flow exceeded 450 ml after complete cessation of oral intake. Radiotherapy consisted of opposed isocentric portals to the mediastinum using 15 MV photon beams from a linear accelerator, a single dose of 1–1.5 Gy, and a maximum of five fractions per week. The radiation target area was the anatomical region between TH3 and TH10 depending on the localization of the resected lobe. The mean doses of the ionizing energy was 8.5 Gy ± 3.5 Gy. Results The median start date of the radiation was the fourth day after chylothorax diagnosis. The patients’ mediastinum was radiated an average of six times. Radiotherapy, in combination with dietary restrictions, was successful in all patients. The median time between the end of the radiation and the removal of the chest tube was one day. One patient underwent wound healing by secondary intention. The median time between the end of radiation and discharge was three days, and the overall hospital stay between the chylothorax diagnosis and discharge was 18 days (range: 11–30 days). After a follow-up of six months, no patient experienced chylothorax recurrence. Conclusions Our results suggest that radiotherapy in combination with dietary restriction in the treatment of postoperative chylothorax is very safe, rapid and successful. This novel interventional procedure can obviate repeat major thoracic surgery and shorten hospital stays and could be the first choice in the treatment of postthoracotomy chylothorax. PMID:23566741

  15. [Impact of radiotherapy on female fertility].

    PubMed

    Mazeron, Renaud; Maroun, Pierre; Cao, Kim; Mbagui, Rodrigue; Slocker-Escarpa, Andrea; Chargari, Cyrus; Haie-Meder, Christine

    2015-05-01

    Radiation therapy may have deleterious effects on female fertility. It can cause ovarian dysfunction, uterine damages or disrupt the hypothalamic-pituitary axis. These effects occur at varying dose levels usually relatively low compared to the prescribed doses. Other co-factors influence the effects of radiation therapy on fertility, such as age or therapy with alkylating agents. This review aims to make an update on the current state of knowledge about the impact of radiotherapy on female fertility.

  16. Radiotherapy equipment--purchase or lease?

    PubMed

    Nisbet, A; Ward, A

    2001-08-01

    Against a background of increasing demand for radiotherapy equipment, this study was undertaken to investigate options for equipment procurement, in particular to compare purchase with lease. The perceived advantages of lease are that equipment can be acquired within budget and cashflow constraints, with relatively low amounts of cash leaving the NHS in the first year, avoiding the necessity of capitalizing the equipment and providing protection against the risk of obsolescence associated with high technology equipment. The perceived disadvantages of leasing are that the Trust does not own the equipment, leasing can be more expensive in revenue terms, the tender process is extended and there may be lease conditions to be met, which may be costly and/or restrictive. There are also a number of technical considerations involved in the leasing of radiotherapy equipment that influence the financial analysis and practical operation of the radiotherapy service. The technical considerations include servicing and planned preventative maintenance, upgrades, spare parts, subsequent purchase of "add ons", modification of equipment, research and development work, commencement of the lease period, return of equipment at the end of the lease period and negotiations at the end of the lease period. A study from Raigmore Hospital, Inverness is described, which involves the procurement of new, state-of-the-art radiotherapy equipment. This provides an overview of the procurement process, including a summary of the advantages and disadvantages of leasing, with the figures from the financial analysis presented and explained. In addition, a detailed description is given of the technical considerations to be taken into account in the financial analysis and negotiation of any lease contract. PMID:11511499

  17. Hypothyroidism After Radiotherapy for Nasopharyngeal Cancer Patients

    SciTech Connect

    Wu, Y.-H.; Wang, H-M.; Chen, Hellen Hi-Wen; Lin, C.-Y.; Chen, Eric Yen-Chao; Fan, K.-H.; Huang, S.-F.; Chen, I-How; Liao, C.-T.; Cheng, Ann-Joy; Chang, Joseph Tung-Chieh

    2010-03-15

    Purpose: The aim of this study was to determine the long-term incidence and possible predictive factors for posttreatment hypothyroidism in nasopharyngeal carcinoma (NPC) patients after radiotherapy. Methods and Materials: Four hundred and eight sequential NPC patients who had received regular annual thyroid hormone surveys prospectively after radiotherapy were included in this study. Median patient age was 47.3 years, and 286 patients were male. Thyroid function was prospectively evaluated by measuring thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) levels. Low FT4 levels indicated clinical hypothyroidism in this study. Results: With a median follow-up of 4.3 years (range, 0.54-19.7 years), the incidence of low FT4 level was 5.3%, 9.0%, and 19.1% at 3, 5, and 10 years after radiotherapy, respectively. Hypothyroidism was more common with early T stage (p = 0.044), female sex (p = 0.037), and three-dimensional conformal therapy with the altered fractionation technique (p = 0.005) after univariate analysis. N stage, chemotherapy, reirradiation, and neck electron boost did not affect the incidence of hypothyroidism. Younger age and conformal therapy were significant factors that determined clinical hypothyroidism after multivariate analysis. Overall, patients presented with a low FT4 level about 1 year after presenting with an elevated TSH level. Conclusion: Among our study group of NPC patients, 19.1% experienced clinical hypothyroidism by 10 years after treatment. Younger age and conformal therapy increased the risk of hypothyroidism. We suggest routine evaluation of thyroid function in NPC patients after radiotherapy. The impact of pituitary injury should be also considered.

  18. Big Data Analytics for Prostate Radiotherapy.

    PubMed

    Coates, James; Souhami, Luis; El Naqa, Issam

    2016-01-01

    Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose-volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the "RadoncSpace") in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches.

  19. Anal Cancer: An Examination of Radiotherapy Strategies

    SciTech Connect

    Glynne-Jones, Rob; Lim, Faye

    2011-04-01

    The Radiation Therapy Oncology Group 9811, ACCORD-03, and ACT II Phase III trials in anal cancer showed no benefit for cisplatin-based induction and maintenance chemotherapy, or radiation dose-escalation >59 Gy. This review examines the efficacy and toxicity of chemoradiation (CRT) in anal cancer, and discusses potential alternative radiotherapy strategies. The evidence for the review was compiled from randomized and nonrandomized trials of radiation therapy and CRT. A total of 103 retrospective/observational studies, 4 Phase I/II studies, 16 Phase II prospective studies, 2 randomized Phase II studies, and 6 Phase III trials of radiotherapy or chemoradiation were identified. There are no meta-analyses based on individual patient data. A 'one-size-fits-all' approach for all stages of anal cancer is inappropriate. Early T1 tumors are probably currently overtreated, whereas T3/T4 lesions might merit escalation of treatment. Intensity-modulated radiotherapy or the integration of biological therapy may play a role in future.

  20. Personalized radiotherapy: concepts, biomarkers and trial design.

    PubMed

    Ree, A H; Redalen, K R

    2015-07-01

    In the past decade, and pointing onwards to the immediate future, clinical radiotherapy has undergone considerable developments, essentially including technological advances to sculpt radiation delivery, the demonstration of the benefit of adding concomitant cytotoxic agents to radiotherapy for a range of tumour types and, intriguingly, the increasing integration of targeted therapeutics for biological optimization of radiation effects. Recent molecular and imaging insights into radiobiology will provide a unique opportunity for rational patient treatment, enabling the parallel design of next-generation trials that formally examine the therapeutic outcome of adding targeted drugs to radiation, together with the critically important assessment of radiation volume and dose-limiting treatment toxicities. In considering the use of systemic agents with presumed radiosensitizing activity, this may also include the identification of molecular, metabolic and imaging markers of treatment response and tolerability, and will need particular attention on patient eligibility. In addition to providing an overview of clinical biomarker studies relevant for personalized radiotherapy, this communication will highlight principles in addressing clinical evaluation of combined-modality-targeted therapeutics and radiation. The increasing number of translational studies that bridge large-scale omics sciences with quality-assured phenomics end points-given the imperative development of open-source data repositories to allow investigators the access to the complex data sets-will enable radiation oncology to continue to position itself with the highest level of evidence within existing clinical practice. PMID:25989697

  1. Accuracy requirements in radiotherapy treatment planning.

    PubMed

    Buzdar, Saeed Ahmad; Afzal, Muhammad; Nazir, Aalia; Gadhi, Muhammad Asghar

    2013-06-01

    Radiation therapy attempts to deliver ionizing radiation to the tumour and can improve the survival chances and/or quality of life of patients. There are chances of errors and uncertainties in the entire process of radiotherapy that may affect the accuracy and precision of treatment management and decrease degree of conformation. All expected inaccuracies, like radiation dose determination, volume calculation, complete evaluation of the full extent of the tumour, biological behaviour of specific tumour types, organ motion during radiotherapy, imaging, biological/molecular uncertainties, sub-clinical diseases, microscopic spread of the disease, uncertainty in normal tissue responses and radiation morbidity need sound appreciation. Conformity can be increased by reduction of such inaccuracies. With the yearly increase in computing speed and advancement in other technologies the future will provide the opportunity to optimize a greater number of variables and reduce the errors in the treatment planning process. In multi-disciplined task of radiotherapy, efforts are needed to overcome the errors and uncertainty, not only by the physicists but also by radiologists, pathologists and oncologists to reduce molecular and biological uncertainties. The radiation therapy physics is advancing towards an optimal goal that is definitely to improve accuracy where necessary and to reduce uncertainty where possible.

  2. Proton beam radiotherapy of iris melanoma

    SciTech Connect

    Damato, Bertil . E-mail: Bertil@damato.co.uk; Kacperek, Andrzej; Chopra, Mona; Sheen, Martin A.; Campbell, Ian R.; Errington, R. Douglas

    2005-09-01

    Purpose: To report on outcomes after proton beam radiotherapy of iris melanoma. Methods and Materials: Between 1993 and 2004, 88 patients with iris melanoma received proton beam radiotherapy, with 53.1 Gy in 4 fractions. Results: The patients had a mean age of 52 years and a median follow-up of 2.7 years. The tumors had a median diameter of 4.3 mm, involving more than 2 clock hours of iris in 32% of patients and more than 2 hours of angle in 27%. The ciliary body was involved in 20%. Cataract was present in 13 patients before treatment and subsequently developed in another 18. Cataract had a 4-year rate of 63% and by Cox analysis was related to age (p = 0.05), initial visual loss (p < 0.0001), iris involvement (p < 0.0001), and tumor thickness (p < 0.0001). Glaucoma was present before treatment in 13 patients and developed after treatment in another 3. Three eyes were enucleated, all because of recurrence, which had an actuarial 4-year rate of 3.3% (95% CI 0-8.0%). Conclusions: Proton beam radiotherapy of iris melanoma is well tolerated, the main problems being radiation-cataract, which was treatable, and preexisting glaucoma, which in several patients was difficult to control.

  3. Cellular signalling effects in high precision radiotherapy

    NASA Astrophysics Data System (ADS)

    McMahon, Stephen J.; McGarry, Conor K.; Butterworth, Karl T.; Jain, Suneil; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

    2015-06-01

    Radiotherapy is commonly planned on the basis of physical dose received by the tumour and surrounding normal tissue, with margins added to address the possibility of geometric miss. However, recent experimental evidence suggests that intercellular signalling results in a given cell’s survival also depending on the dose received by neighbouring cells. A model of radiation-induced cell killing and signalling was used to analyse how this effect depends on dose and margin choices. Effective Uniform Doses were calculated for model tumours in both idealised cases with no delivery uncertainty and more realistic cases incorporating geometric uncertainty. In highly conformal irradiation, a lack of signalling from outside the target leads to reduced target cell killing, equivalent to under-dosing by up to 10% compared to large uniform fields. This effect is significantly reduced when higher doses per fraction are considered, both increasing the level of cell killing and reducing margin sensitivity. These effects may limit the achievable biological precision of techniques such as stereotactic radiotherapy even in the absence of geometric uncertainties, although it is predicted that larger fraction sizes reduce the relative contribution of cell signalling driven effects. These observations may contribute to understanding the efficacy of hypo-fractionated radiotherapy.

  4. Personalized radiotherapy: concepts, biomarkers and trial design

    PubMed Central

    Redalen, K R

    2015-01-01

    In the past decade, and pointing onwards to the immediate future, clinical radiotherapy has undergone considerable developments, essentially including technological advances to sculpt radiation delivery, the demonstration of the benefit of adding concomitant cytotoxic agents to radiotherapy for a range of tumour types and, intriguingly, the increasing integration of targeted therapeutics for biological optimization of radiation effects. Recent molecular and imaging insights into radiobiology will provide a unique opportunity for rational patient treatment, enabling the parallel design of next-generation trials that formally examine the therapeutic outcome of adding targeted drugs to radiation, together with the critically important assessment of radiation volume and dose-limiting treatment toxicities. In considering the use of systemic agents with presumed radiosensitizing activity, this may also include the identification of molecular, metabolic and imaging markers of treatment response and tolerability, and will need particular attention on patient eligibility. In addition to providing an overview of clinical biomarker studies relevant for personalized radiotherapy, this communication will highlight principles in addressing clinical evaluation of combined-modality-targeted therapeutics and radiation. The increasing number of translational studies that bridge large-scale omics sciences with quality-assured phenomics end points—given the imperative development of open-source data repositories to allow investigators the access to the complex data sets—will enable radiation oncology to continue to position itself with the highest level of evidence within existing clinical practice. PMID:25989697

  5. Multimedia educational services in stereotactic radiotherapy.

    PubMed

    Bazioglou, M; Theodorou, K; Kappas, C

    1999-01-01

    The computer-based learning methods in medicine have been well established as stand-alone learning systems. Recently, these systems were enriched with the use of telematics technology to provide distance learning capabilities. Stereotactic radiotherapy is one of the most representative advanced radiotherapy techniques. Due to the multidisciplinary character of the technique and the rapid evolution of technology implemented, the demands in training have increased. The potential of interactive multimedia and Internet technologies for the achievement of distance learning capabilities in this domain are investigated. The realization of a computer-based educational program in stereotactic radiotherapy in a multimedia format is a new application in the computer-aided distance learning field. The system is built according to a client and server architecture, based on the Internet infrastructure, and composed of server nodes. The impact of the system may be described in terms of: time and transportation costs saving, flexibility in training (scheduling, rate and subject selection), online communication and interaction with experts, cost effective access to material (delivery or access by a large number of users and revision of the material by avoiding high costs of computer-based training systems and database development). PMID:10394345

  6. [3D reconstructions in radiotherapy planning].

    PubMed

    Schlegel, W

    1991-10-01

    3D Reconstructions from tomographic images are used in the planning of radiation therapy to study important anatomical structures such as the body surface, target volumes, and organs at risk. The reconstructed anatomical models are used to define the geometry of the radiation beams. In addition, 3D voxel models are used for the calculation of the 3D dose distributions with an accuracy, previously impossible to achieve. Further uses of 3D reconstructions are in the display and evaluation of 3D therapy plans, and in the transfer of treatment planning parameters to the irradiation situation with the help of digitally reconstructed radiographs. 3D tomographic imaging with subsequent 3D reconstruction must be regarded as a completely new basis for the planning of radiation therapy, enabling tumor-tailored radiation therapy of localized target volumes with increased radiation doses and improved sparing of organs at risk. 3D treatment planning is currently being evaluated in clinical trials in connection with the new treatment techniques of conformation radiotherapy. Early experience with 3D treatment planning shows that its clinical importance in radiotherapy is growing, but will only become a standard radiotherapy tool when volumetric CT scanning, reliable and user-friendly treatment planning software, and faster and cheaper PACS-integrated medical work stations are accessible to radiotherapists.

  7. Errors in Radiotherapy: Motivation for Development of New Radiotherapy Quality Assurance Paradigms

    SciTech Connect

    Fraass, Benedick A.

    2008-05-01

    Modern radiotherapy practice has rapidly evolved during the past decade, making use of many highly complex and/or automated processes for planning and delivery, including new techniques, like intensity-modulated radiotherapy driven by inverse planning optimization methods, or near real-time image-guided adaptive therapy based on fluoroscopic or tomographic imaging on the treatment machine. In spite of the modern technology, or potentially because of it in some instances, errors and other problems continue to have a significant impact on the field. This report reviews example errors and problems, discusses some of the quality assurance issues that these types of problems raise, and motivates the development of more modern and sophisticated approaches to assure quality for our clinical radiotherapy treatment methods.

  8. Genome-wide transcription responses to synchrotron microbeam radiotherapy.

    PubMed

    Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

    2012-10-01

    The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

  9. Proton Radiotherapy for Liver Tumors: Dosimetric Advantages Over Photon Plans

    SciTech Connect

    Wang Xiaochun Krishnan, Sunil; Zhang Xiaodong; Dong Lei; Briere, Tina; Crane, Christopher H.; Martel, Mary; Gillin, Michael; Mohan, Radhe; Beddar, Sam

    2008-01-01

    The purpose of the study is to dosimetrically investigate the advantages of proton radiotherapy over photon radiotherapy for liver tumors. The proton plan and the photon plan were designed using commercial treatment planning systems. The treatment target dose conformity and heterogeneity and dose-volume analyses of normal structures were compared between proton and photon radiotherapy for 9 patients with liver tumors. Proton radiotherapy delivered a more conformal target dose with slightly less homogeneity when compared with photon radiotherapy. Protons significantly reduced the fractional volume of liver receiving dose greater or equal to 30 Gy (V{sub 30}) and the mean liver dose. The stomach and duodenal V{sub 45} were significantly lower with the use of proton radiotherapy. The V{sub 40} and V{sub 50} of the heart and the maximum spinal cord dose were also significantly lower with the use of proton radiotherapy. Protons were better able to spare one kidney completely and deliver less dose to one (generally the left) kidney than photons. The mean dose to the total body and most critical structures was significantly decreased using protons when compared to corresponding photon plans. In conclusion, our study suggests the dosimetric benefits of proton radiotherapy over photon radiotherapy. These dosimetric advantages of proton plans may permit further dose escalation with lower risk of complications.

  10. Dysphagia after radiotherapy: state of the art and prevention.

    PubMed

    Servagi-Vernat, S; Ali, D; Roubieu, C; Durdux, C; Laccourreye, O; Giraud, P

    2015-02-01

    Adjuvant radiotherapy after surgery or exclusive radiotherapy, with or without concurrent chemotherapy is a valuable treatment option in the great majority of patients with head and neck cancer. Recent technical progress in radiotherapy has resulted in a decreased incidence of xerostomia. Another common toxicity of radiotherapy is dysphagia, which alters the nutritional status and quality of life of patients in remission. The objective of this review is to describe the physiology of swallowing function, the pathophysiology of radiation-induced dysphagia and the various strategies currently available to prevent this complication.

  11. Genome-wide transcription responses to synchrotron microbeam radiotherapy.

    PubMed

    Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

    2012-10-01

    The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam. PMID:22974124

  12. Effectiveness of Radiotherapy for Elderly Patients With Glioblastoma

    SciTech Connect

    Scott, Jacob; Tsai, Ya-Yu; Chinnaiyan, Prakash; Yu, Hsiang-Hsuan Michael

    2011-09-01

    Purpose: Radiotherapy plays a central role in the definitive treatment of glioblastoma. However, the optimal management of elderly patients with glioblastoma remains controversial, as the relative benefit in this patient population is unclear. To better understand the role that radiation plays in the treatment of glioblastoma in the elderly, we analyzed factors influencing patient survival using a large population-based registry. Methods and Materials: A total of 2,836 patients more than 70 years of age diagnosed with glioblastoma between 1993 and 2005 were identified from the Surveillance, Epidemiology, and End Results (SEER) registry. Demographic and clinical variables used in the analysis included gender, ethnicity, tumor size, age at diagnosis, surgery, and radiotherapy. Cancer-specific survival and overall survival were evaluated using the Kaplan-Meier method. Univariate and multivariate analysis were performed using Cox regression. Results: Radiotherapy was administered in 64% of these patients, and surgery was performed in 68%. Among 2,836 patients, 46% received surgery and radiotherapy, 22% underwent surgery only, 18% underwent radiotherapy only, and 14% did not undergo either treatment. The median survival for patients who underwent surgery and radiotherapy was 8 months. The median survival for patients who underwent radiotherapy only was 4 months, and for patients who underwent surgery only was 3 months. Those who received neither surgery nor radiotherapy had a median survival of 2 months (p < 0.001). Multivariate analysis showed that radiotherapy significantly improved cancer-specific survival (hazard ratio [HR], 0.43, 95% confidence interval [CI] 0.38-0.49) after adjusting for surgery, tumor size, gender, ethnicity, and age at diagnosis. Other factors associated with Cancer-specific survival included surgery, tumor size, age at diagnosis, and ethnicity. Analysis using overall survival as the endpoint yielded very similar results. Conclusions: Elderly

  13. Children Undergoing Radiotherapy: Swedish Parents' Experiences and Suggestions for Improvement.

    PubMed

    Ångström-Brännström, Charlotte; Engvall, Gunn; Mullaney, Tara; Nilsson, Kristina; Wickart-Johansson, Gun; Svärd, Anna-Maja; Nyholm, Tufve; Lindh, Jack; Lindh, Viveca

    2015-01-01

    Approximately 300 children, from 0 to 18 years old, are diagnosed with cancer in Sweden every year. Of these children, 80-90 of them undergo radiotherapy treatment for their cancer. Although radiotherapy is an encounter with advanced technology, few studies have investigated the child's and the parent's view of the procedure. As part of an ongoing multicenter study aimed to improve patient preparation and the care environment in pediatric radiotherapy, this article reports the findings from interviews with parents at baseline. The aim of the present study was twofold: to describe parents' experience when their child undergoes radiotherapy treatment, and to report parents' suggestions for improvements during radiotherapy for their children. Sixteen mothers and sixteen fathers of children between 2-16 years old with various cancer diagnoses were interviewed. Data were analyzed using content analysis. The findings showed that cancer and treatment turns people's lives upside down, affecting the entire family. Further, the parents experience the child's suffering and must cope with intense feelings. Radiotherapy treatment includes preparation by skilled and empathetic staff. The parents gradually find that they can deal with the process; and lastly, parents have suggestions for improvements during the radiotherapy treatment. An overarching theme emerged: that despair gradually turns to a sense of security, with a sustained focus on and close interaction with the child. In conclusion, an extreme burden was experienced around the start of radiotherapy, though parents gradually coped with the process.

  14. Updates on clinical studies of selenium supplementation in radiotherapy

    PubMed Central

    2014-01-01

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200–500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation. PMID:24885670

  15. Optimal radiotherapy utilisation rate in developing countries: An IAEA study.

    PubMed

    Rosenblatt, Eduardo; Barton, Michael; Mackillop, William; Fidarova, Elena; Cordero, Lisbeth; Yarney, Joel; Lim, Gerard; Abad, Anthony; Cernea, Valentin; Stojanovic-Rundic, Suzana; Strojan, Primoz; Kobachi, Lotfi; Quarneti, Aldo

    2015-07-01

    Optimal radiotherapy utilisation rate (RTU) is the proportion of all cancer cases that should receive radiotherapy. Optimal RTU was estimated for 9 Middle Income Countries as part of a larger IAEA project to better understand RTU and stage distribution. PMID:26164776

  16. Children Undergoing Radiotherapy: Swedish Parents’ Experiences and Suggestions for Improvement

    PubMed Central

    Mullaney, Tara; Nilsson, Kristina; Wickart-Johansson, Gun; Svärd, Anna-Maja; Nyholm, Tufve; Lindh, Jack; Lindh, Viveca

    2015-01-01

    Approximately 300 children, from 0 to 18 years old, are diagnosed with cancer in Sweden every year. Of these children, 80–90 of them undergo radiotherapy treatment for their cancer. Although radiotherapy is an encounter with advanced technology, few studies have investigated the child’s and the parent’s view of the procedure. As part of an ongoing multicenter study aimed to improve patient preparation and the care environment in pediatric radiotherapy, this article reports the findings from interviews with parents at baseline. The aim of the present study was twofold: to describe parents’ experience when their child undergoes radiotherapy treatment, and to report parents’ suggestions for improvements during radiotherapy for their children. Sixteen mothers and sixteen fathers of children between 2–16 years old with various cancer diagnoses were interviewed. Data were analyzed using content analysis. The findings showed that cancer and treatment turns people’s lives upside down, affecting the entire family. Further, the parents experience the child’s suffering and must cope with intense feelings. Radiotherapy treatment includes preparation by skilled and empathetic staff. The parents gradually find that they can deal with the process; and lastly, parents have suggestions for improvements during the radiotherapy treatment. An overarching theme emerged: that despair gradually turns to a sense of security, with a sustained focus on and close interaction with the child. In conclusion, an extreme burden was experienced around the start of radiotherapy, though parents gradually coped with the process. PMID:26509449

  17. Toxicity of oral radiotherapy in patients with acquired immunodeficiency syndrome

    SciTech Connect

    Cooper, J.S.; Fried, P.R.

    1987-03-01

    Although radiotherapy is a standard form of management of head and neck tumors, treatment of the oral cavity in patients who have the acquired immunodeficiency syndrome has produced unacceptable toxicity. Five such patients are described as a warning of enhanced toxicity of oral radiotherapy in this patient population.

  18. WEE1 inhibition sensitizes osteosarcoma to radiotherapy

    PubMed Central

    2011-01-01

    Background The use of radiotherapy in osteosarcoma (OS) is controversial due to its radioresistance. OS patients currently treated with radiotherapy generally are inoperable, have painful skeletal metastases, refuse surgery or have undergone an intralesional resection of the primary tumor. After irradiation-induced DNA damage, OS cells sustain a prolonged G2 cell cycle checkpoint arrest allowing DNA repair and evasion of cell death. Inhibition of WEE1 kinase leads to abrogation of the G2 arrest and could sensitize OS cells to irradiation induced cell death. Methods WEE1 expression in OS was investigated by gene-expression data analysis and immunohistochemistry of tumor samples. WEE1 expression in OS cell lines and human osteoblasts was investigated by Western blot. The effect of WEE1 inhibition on the radiosensitivity of OS cells was assessed by cell viability and caspase activation analyses after combination treatment. The presence of DNA damage was visualized using immunofluorescence microscopy. Cell cycle effects were investigated by flow cytometry and WEE1 kinase regulation was analyzed by Western blot. Results WEE1 expression is found in the majority of tested OS tissue samples. Small molecule drug PD0166285 inhibits WEE1 kinase activity. In the presence of WEE1-inhibitor, irradiated cells fail to repair their damaged DNA, and show higher levels of caspase activation. The inhibition of WEE1 effectively abrogates the irradiation-induced G2 arrest in OS cells, forcing the cells into premature, catastrophic mitosis, thus enhancing cell death after irradiation treatment. Conclusion We show that PD0166285, a small molecule WEE1 kinase inhibitor, can abrogate the G2 checkpoint in OS cells, pushing them into mitotic catastrophe and thus sensitizing OS cells to irradiation-induced cell death. This suggests that WEE1 inhibition may be a promising strategy to enhance the radiotherapy effect in patients with OS. PMID:21529352

  19. Big Data Analytics for Prostate Radiotherapy

    PubMed Central

    Coates, James; Souhami, Luis; El Naqa, Issam

    2016-01-01

    Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose–volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the “RadoncSpace”) in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches. PMID:27379211

  20. Dosimetry audit of radiotherapy treatment planning systems.

    PubMed

    Bulski, Wojciech; Chełmiński, Krzysztof; Rostkowska, Joanna

    2015-07-01

    In radiotherapy Treatment Planning Systems (TPS) various calculation algorithms are used. The accuracy of dose calculations has to be verified. Numerous phantom types, detectors and measurement methodologies are proposed to verify the TPS calculations with dosimetric measurements. A heterogeneous slab phantom has been designed within a Coordinated Research Project (CRP) of the IAEA. The heterogeneous phantom was developed in the frame of the IAEA CRP. The phantom consists of frame slabs made with polystyrene and exchangeable inhomogeneity slabs equivalent to bone or lung tissue. Special inserts allow to position thermoluminescent dosimeters (TLD) capsules within the polystyrene slabs below the bone or lung equivalent slabs and also within the lung equivalent material. Additionally, there are inserts that allow to position films or ionisation chamber in the phantom. Ten Polish radiotherapy centres (of 30 in total) were audited during on-site visits. Six different TPSs and five calculation algorithms were examined in the presence of inhomogeneities. Generally, most of the results from TLD were within 5 % tolerance. Differences between doses calculated by TPSs and measured with TLD did not exceed 4 % for bone and polystyrene equivalent materials. Under the lung equivalent material, on the beam axis the differences were lower than 5 %, whereas inside the lung equivalent material, off the beam axis, in some cases they were of around 7 %. The TLD results were confirmed with the ionisation chamber measurements. The comparison results of the calculations and the measurements allow to detect limitations of TPS calculation algorithms. The audits performed with the use of heterogeneous phantom and TLD seem to be an effective tool for detecting the limitations in the TPS performance or beam configuration errors at audited radiotherapy departments.

  1. Clinical Applications of 3-D Conformal Radiotherapy

    NASA Astrophysics Data System (ADS)

    Miralbell, Raymond

    Although a significant improvement in cancer cure (i.e. 20% increment) has been obtained in the last 2-3 decades, 30-40% of patients still fail locally after curative radiotherapy. In order to improve local tumor control rates with radiotherapy high doses to the tumor volume are frequently necessary. Three-dimensional conformal radiation therapy (3-D CRT) is used to denote a spectrum of radiation planning and delivery techniques that rely on three-dimensional imaging to define the target (tumor) and to distinguish it from normal tissues. Modern, high-precision radiotherapy (RT) techniques are needed in order to implement the goal of optimal tumor destruction delivering minimal dose to the non-target normal tissues. A better target definition is nowadays possible with contemporary imaging (computerized tomography, magnetic resonance imaging, and positron emission tomography) and image registration technology. A highly precise dose distributions can be obtained with optimal 3-D CRT treatment delivery techniques such as stereotactic RT, intensity modulated RT (IMRT), or protontherapy (the latter allowing for in-depth conformation). Patient daily set-up repositioning and internal organ immobilization systems are necessary before considering to undertake any of the above mentioned high-precision treatment approaches. Prostate cancer, brain tumors, and base of skull malignancies are among the sites most benefitting of dose escalation approaches. Nevertheless, a significant dose reduction to the normal tissues in the vicinity of the irradiated tumor also achievable with optimal 3-D CRT may also be a major issue in the treatment of pediatric tumors in order to preserve growth, normal development, and to reduce the risk of developing radiation induced diseases such as cancer or endocrinologic disorders.

  2. Our intraoperative boost radiotherapy experience and applications

    PubMed Central

    Günay, Semra; Alan, Ömür; Yalçın, Orhan; Türkmen, Aygen; Dizdar, Nihal

    2016-01-01

    Objective: To present our experience since November 2013, and case selection criteria for intraoperative boost radiotherapy (IObRT) that significantly reduces the local recurrence rate after breast conserving surgery in patients with breast cancer. Material and Methods: Patients who were suitable for IObRT were identified within the group of patients who were selected for breast conserving surgery at our breast council. A MOBETRON (mobile linear accelerator for IObRT) was used for IObRt during surgery. Results: Patients younger than 60 years old with <3 cm invasive ductal cancer in one focus (or two foci within 2 cm), with a histologic grade of 2–3, and a high possibility of local recurrence were admitted for IObRT application. Informed consent was obtained from all participants. Lumpectomy and sentinel lymph node biopsy was performed and advancement flaps were prepared according to the size and inclination of the conus following evaluation of tumor size and surgical margins by pathology. Distance to the thoracic wall was measured, and a radiation oncologist and radiation physicist calculated the required dose. Anesthesia was regulated with slower ventilation frequency, without causing hypoxia. The skin and incision edges were protected, the field was radiated (with 6 MeV electron beam of 10 Gy) and the incision was closed. In our cases, there were no major postoperative surgical or early radiotherapy related complications. Conclusion: The completion of another stage of local therapy with IObRT during surgery positively effects sequencing of other treatments like chemotherapy, hormonotherapy and radiotherapy, if required. IObRT increases disease free and overall survival, as well as quality of life in breast cancer patients. PMID:26985156

  3. Big Data Analytics for Prostate Radiotherapy.

    PubMed

    Coates, James; Souhami, Luis; El Naqa, Issam

    2016-01-01

    Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose-volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the "RadoncSpace") in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches. PMID:27379211

  4. Surgery Followed by Radiotherapy Versus Radiotherapy Alone for Metastatic Spinal Cord Compression From Unfavorable Tumors

    SciTech Connect

    Rades, Dirk; Huttenlocher, Stefan; Bajrovic, Amira; Karstens, Johann H.; Adamietz, Irenaeus A.; Kazic, Nadja; Rudat, Volker; Schild, Steven E.

    2011-12-01

    Purpose: Despite a previously published randomized trial, controversy exists regarding the benefit of adding surgery to radiotherapy for metastatic spinal cord compression (MSCC). It is thought that patients with MSCC from relatively radioresistant tumors or tumors associated with poor functional outcome after radiotherapy alone may benefit from surgery. This study focuses on these tumors. Methods and Materials: Data from 67 patients receiving surgery plus radiotherapy (S+RT) were matched to 134 patients (1:2) receiving radiotherapy alone (RT). Groups were matched for 10 factors and compared for motor function, ambulatory status, local control, and survival. Additional separate matched-pair analyses were performed for patients receiving direct decompressive surgery plus stabilization of involved vertebrae (DDSS) and patients receiving laminectomy (LE). Results: Improvement of motor function occurred in 22% of patients after S+RT and 16% after RT (p = 0.25). Posttreatment ambulatory rates were 67% and 61%, respectively (p = 0.68). Of nonambulatory patients, 29% and 19% (p = 0.53) regained ambulatory status. One-year local control rates were 85% and 89% (p = 0.87). One-year survival rates were 38% and 24% (p = 0.20). The matched-pair analysis of patients receiving LE showed no significant differences between both therapies. In the matched-pair analysis of patients receiving DDSS, improvement of motor function occurred more often after DDSS+RT than RT (28% vs. 19%, p = 0.024). Posttreatment ambulatory rates were 86% and 67% (p = 0.30); 45% and 18% of patients regained ambulatory status (p = 0.29). Conclusions: Patients with MSCC from an unfavorable primary tumor appeared to benefit from DDSS but not LE when added to radiotherapy in terms of improved functional outcome.

  5. Ichthyosiform scaling secondary to megavoltage radiotherapy

    SciTech Connect

    Ross, E.V. )

    1991-07-01

    Acquired ichthyosis is a rare dermatosis associated with a number of malignancies. Side effects seen on the skin secondary to megavoltage radiotherapy are uncommon but may include fine dry desquamation and tanning. The authors present a case of ichthyosiform scaling limited to the radiation fields in a patient treated for brain metastases of a primary small cell lung carcinoma. The reader is reminded that side effects of megavoltage treatment do occur on the skin. A brief review of these effects is included. 5 references.

  6. Intestinal lymphangiectasia secondary to radiotherapy and chemotherapy

    SciTech Connect

    Rao, S.S.; Dundas, S.; Holdsworth, C.D.

    1987-08-01

    We report a case of intestinal lymphangiectasia secondary to radiotherapy and chemotherapy. The patient also had small bowel bacterial overgrowth and pancreatic insufficiency. Lymphatic ectasia as a histological feature has been described previously in association with postradiotherapy malabsorption, but radiation-induced lymphangiectasia producing clinical manifestations has hitherto not been reported. Replacement of dietary long-chain fats with medium-chain triglycerides, pancreatic enzyme supplements, and a short course of oxytetracycline, resulted in dramatic clinical improvement. The possibility of intestinal lymphangiectasia should be borne in mind in patients with postradiotherapy malabsorption. A low serum albumin and lymphocyte count should draw attention to this possibility.

  7. Breast Molecular Profiling and Radiotherapy Considerations.

    PubMed

    Mahmoud, Omar; Haffty, Bruce G

    2016-01-01

    The last decade has seen major changes in the management of breast cancer. Heterogeneity regarding histology, therapeutic response, dissemination patterns, and patient outcome is evident. Molecular profiling provides an accurate tool to predict treatment outcome compared with classical clinicopathologic features. The genomic profiling unveiled the heterogeneity of breast cancer and identified distinct biologic subtypes. These advanced techniques were integrated into the clinical management; predicting systemic therapy benefit and overall survival. Utilizing genotyping to guide locoregional management decisions needs further characterization. In this chapter we will review available data on molecular classification of breast cancer, their association with locoregional outcome, their radiobiological properties and radiotherapy considerations. PMID:26987532

  8. [Quality and safety management for radiotherapy].

    PubMed

    Pourel, N; Meyrieux, C; Perrin, B

    2016-09-01

    Quality and safety management have been implemented for many years in healthcare structures (hospitals treating cancer, private radiotherapy centres). Their structure and formalization have improved progressively over time. These recommendations aim at describing the link between quality and safety management through its organization scheme based on quality-safety policy, process approach, document management and quality measurement. Dedicated tools, such as experience feedback, a priori risk mapping, to-do-lists and check-lists are shown as examples and recommended as routine practice. PMID:27523420

  9. Effects of radiotherapy on human parotid saliva

    SciTech Connect

    Mossman, K.L.; Shatzman, A.R.; Chencharick, J.D.

    1981-11-01

    Changes in parotide salivary function, as determined by flow rate and protein secretion, were measured in 31 cancer patients given radiotherapy to the head and neck. After the first week of treatment, a 50% decrease in salivary flow rate and a 60% decrease in protein secretion rate were observed. Salivary function remained at or below these levels during the next 3 week of treatment. Proteins in saliva were affected unequally, with the family of glycoproteins exhibiting greater sensitivity than amylase. Chromatography or irradiated (60 Gy) and unirradiated whole parotid saliva suggests that the observed alterations in salivary protein may be due to radiation effects on protein synthesis rather than on the proteins themselves.

  10. Dosimetric comparison of three-dimensional conformal radiotherapy, intensity modulated radiotherapy, and helical tomotherapy for lung stereotactic body radiotherapy

    PubMed Central

    Kinhikar, Rajesh Ashok; Ghadi, Yogesh G.; Sahoo, Priyadarshini; Laskar, Sarbani Ghosh; Deshpande, Deepak D.; Shrivastava, Shyam K.; Agarwal, Jaiprakash

    2015-01-01

    To compare the treatment plans generated with three-dimensional conformal radiation therapy (3DCRT), intensity modulated radiotherapy (IMRT), and helical tomotherapy (HT) for stereotactic body radiotherapy of lung, twenty patients with medically inoperable (early nonsmall cell lung cancer) were retrospectively reviewed for dosimetric evaluation of treatment delivery techniques (3DCRT, IMRT, and HT). A dose of 6 Gy per fraction in 8 fractions was prescribed to deliver 95% of the prescription dose to 95% volume of planning target volume (PTV). Plan quality was assessed using conformity index (CI) and homogeneity index (HI). Doses to critical organs were assessed. Mean CI with 3DCRT, IMRT, and HT was 1.19 (standard deviation [SD] 0.13), 1.18 (SD 0.11), and 1.08 (SD 0.04), respectively. Mean HI with 3DCRT, IMRT, and HT was 1.14 (SD 0.05), 1.08 (SD 0.02), and 1.07 (SD 0.04), respectively. Mean R50% values for 3DCRT, IMRT, and HT was 8.5 (SD 0.35), 7.04 (SD 0.45), and 5.43 (SD 0.29), respectively. D2cm was found superior with IMRT and HT. Significant sparing of critical organs can be achieved with highly conformal techniques (IMRT and HT) without compromising the PTV conformity and homogeneity. PMID:26865754

  11. In vivo dosimetry in external beam radiotherapy

    SciTech Connect

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  12. External beam radiotherapy for prostate cancer.

    PubMed

    Budiharto, Tom; Haustermans, Karin; Kovacs, Gyoergy

    2010-05-01

    External beam radiotherapy (EBRT) constitutes an important management option for prostate cancer (PCa). Radiation doses >or=74 Gy are warranted. Dose escalation of EBRT using three-dimensional-conformal radiotherapy (RT) or intensity-modulated RT improves the therapeutic index by minimizing normal tissue complication probability and increasing tumor control probability. Although higher doses are associated with better biochemical disease-free survival, no impact on local recurrence or overall survival has been demonstrated. Hypofractionation for PCa may be an attractive therapeutic option, but toxicity data need to be confirmed in randomized phase III trials. Advances in RT technology, such as volumetric modulated arc therapy and image-guided RT, could facilitate the introduction of dose escalation and hypofractionation into clinical practice. Particle beam irradiation and more specific carbon ion RT are also very promising new techniques that are under investigation. Ultimately, these techniques may lead to focal dose escalation by selective boosting of dominant intraprostatic lesions, which is currently under investigation as a solution to overcome increased toxicity of homogenous dose escalation. This review will give a comprehensive overview of all the recent advances in these new radiation therapy techniques.

  13. Cataractogenesis after Cobalt-60 eye plaque radiotherapy

    SciTech Connect

    Kleineidam, M.; Augsburger, J.J. ); Hernandez, C.; Glennon, P.; Brady, L.W. )

    1993-07-15

    This study was designed to estimate the actuarial incidence of typical postirradiation cataracts and to identify prognostic factors related to their development in melanoma-containing eyes treated by Cobalt-60 plaque radiotherapy. A special interest was the impact of calculated radiation dose and dose-rate to the lens. The authors evaluated the actuarial occurrence of post-irradiation cataract in 365 patients with primary posterior uveal melanoma treated by Cobalt-60 plaque radiotherapy between 1976 and 1986. Only 22% (S.E. = 4.6%) of the patients who received a total dose of 6 to 20 Gy at the center of the lens developed a visually significant cataract attributable to the radiation within 5 years after treatment. Using multivariate Cox proportional hazards modeling, the authors identified thickness of the tumor, location of the tumor's anterior margin relative to the equatorward and the ora serrata, and diameter of the eye plaque used as the best combination of covariables for predicting length of time until development of cataract. Surprisingly, the dose of radiation delivered to the lens, which was strongly correlated to all of these covariables, was not a significant predictive factor in multivariate analysis. The results suggest that success of efforts to decrease the occurrence rate of post-irradiation cataracts by better treatment planning might be limited in patients with posterior uveal melanoma. 21 refs., 2 figs., 5 tabs.

  14. Radiotherapy dosimetry using a commercial OSL system

    SciTech Connect

    Viamonte, A.; Rosa, L. A. R. da; Buckley, L. A.; Cherpak, A.; Cygler, J. E.

    2008-04-15

    A commercial optically stimulated luminescence (OSL) system developed for radiation protection dosimetry by Landauer, Inc., the InLight microStar reader, was tested for dosimetry procedures in radiotherapy. The system uses carbon-doped aluminum oxide, Al{sub 2}O{sub 3}:C, as a radiation detector material. Using this OSL system, a percent depth dose curve for {sup 60}Co gamma radiation was measured in solid water. Field size and SSD dependences of the detector response were also evaluated. The dose response relationship was investigated between 25 and 400 cGy. The decay of the response with time following irradiation and the energy dependence of the Al{sub 2}O{sub 3}:C OSL detectors were also measured. The results obtained using OSL dosimeters show good agreement with ionization chamber and diode measurements carried out under the same conditions. Reproducibility studies show that the response of the OSL system to repeated exposures is 2.5% (1sd), indicating a real possibility of applying the Landauer OSL commercial system for radiotherapy dosimetric procedures.

  15. Radiotherapy dosimetry using a commercial OSL system.

    PubMed

    Viamonte, A; da Rosa, L A R; Buckley, L A; Cherpak, A; Cygler, J E

    2008-04-01

    A commercial optically stimulated luminescence (OSL) system developed for radiation protection dosimetry by Landauer, Inc., the InLight microStar reader, was tested for dosimetry procedures in radiotherapy. The system uses carbon-doped aluminum oxide, Al2O3:C, as a radiation detector material. Using this OSL system, a percent depth dose curve for 60Co gamma radiation was measured in solid water. Field size and SSD dependences of the detector response were also evaluated. The dose response relationship was investigated between 25 and 400 cGy. The decay of the response with time following irradiation and the energy dependence of the Al2O3:C OSL detectors were also measured. The results obtained using OSL dosimeters show good agreement with ionization chamber and diode measurements carried out under the same conditions. Reproducibility studies show that the response of the OSL system to repeated exposures is 2.5% (1sd), indicating a real possibility of applying the Landauer OSL commercial system for radiotherapy dosimetric procedures. PMID:18491518

  16. [Technical record in radiotherapy (author's transl)].

    PubMed

    Le Dorze, C; Horiot, J C; Laugier, A

    1977-11-01

    The term "technical record in radiotherapy" is used to describe collected information relative to treatment using radiation. The subject of this session of the chapter of Radiotherapy of the Société Française de Radiologie was the intrinsic functions of this record and its extrinsic limitations. The extreme diversity of the current state of the record is a known fact. A majority of participants express the desire for uniformisation of the collection of data or even, as a second stage, to have a common record. A library of technical records was set up under the responsibility of the Centre Georges-François Leclerc at Dijon (J.C. Horiot). One broad conclusion was seen to emerge: the creation of a minimum common record including essential information to which could be added the more specific data of each radiotherapist and at each time of use. Prior agreement will be necessary with regard to the standardisation of apparatus and the expression of the dose. This session was of necessity merely a reflection of future needs and it is to be hoped that the good will which was obvious during the course of the discussion may produce concrete results in the months to come.

  17. Liver-Directed Radiotherapy for Hepatocellular Carcinoma

    PubMed Central

    Keane, Florence K.; Wo, Jennifer Y.; Zhu, Andrew X.; Hong, Theodore S.

    2016-01-01

    Background The incidence of hepatocellular carcinoma (HCC) continues to increase world-wide. Many patients present with advanced disease with extensive local tumor or vascular invasion and are not candidates for traditionally curative therapies such as orthotopic liver transplantation (OLT) or resection. Radiotherapy (RT) was historically limited by its inability to deliver a tumoricidal dose; however, modern RT techniques have prompted renewed interest in the use of liver-directed RT to treat patients with primary hepatic malignancies. Summary The aim of this review was to discuss the use of external beam RT in the treatment of HCC, with particular focus on the use of stereotactic body radiotherapy (SBRT). We review the intricacies of SBRT treatment planning and delivery. Liver-directed RT involves accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. We also summarize the published data on liver-directed RT, and demonstrate that it is associated with excellent local control and survival rates, particularly in patients who are not candidates for OLT or resection. Key Messages Modern liver-directed RT is safe and effective for the treatment of HCC, particularly in patients who are not candidates for OLT or resection. Liver-directed RT, including SBRT, depends on accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. Further prospective studies are needed to fully delineate the role of liver-directed RT in the treatment of HCC. PMID:27493895

  18. Dose masking feature for BNCT radiotherapy planning

    DOEpatents

    Cook, Jeremy L.; Wessol, Daniel E.; Wheeler, Floyd J.

    2000-01-01

    A system for displaying an accurate model of isodoses to be used in radiotherapy so that appropriate planning can be performed prior to actual treatment on a patient. The nature of the simulation of the radiotherapy planning for BNCT and Fast Neutron Therapy, etc., requires that the doses be computed in the entire volume. The "entire volume" includes the patient and beam geometries as well as the air spaces in between. Isodoses derived from the computed doses will therefore extend into the air regions between the patient and beam geometries and thus depict the unrealistic possibility that radiation deposition occurs in regions containing no physical media. This problem is solved by computing the doses for the entire geometry and then masking the physical and air regions along with the isodose contours superimposed over the patient image at the corresponding plane. The user is thus able to mask out (remove) the contour lines from the unwanted areas of the image by selecting the appropriate contour masking region from the raster image.

  19. Predicting toxicity in radiotherapy for prostate cancer.

    PubMed

    Landoni, Valeria; Fiorino, Claudio; Cozzarini, Cesare; Sanguineti, Giuseppe; Valdagni, Riccardo; Rancati, Tiziana

    2016-03-01

    This comprehensive review addresses most organs at risk involved in planning optimization for prostate cancer. It can be considered an update of a previous educational review that was published in 2009 (Fiorino et al., 2009). The literature was reviewed based on PubMed and MEDLINE database searches (from January 2009 up to September 2015), including papers in press; for each section/subsection, key title words were used and possibly combined with other more general key-words (such as radiotherapy, dose-volume effects, NTCP, DVH, and predictive model). Publications generally dealing with toxicity without any association with dose-volume effects or correlations with clinical risk factors were disregarded, being outside the aim of the review. A focus was on external beam radiotherapy, including post-prostatectomy, with conventional fractionation or moderate hypofractionation (<4Gy/fraction); extreme hypofractionation is the topic of another paper in this special issue. Gastrointestinal and urinary toxicity are the most investigated endpoints, with quantitative data published in the last 5years suggesting both a dose-response relationship and the existence of a number of clinical/patient related risk factors acting as dose-response modifiers. Some results on erectile dysfunction, bowel toxicity and hematological toxicity are also presented. PMID:27068274

  20. A scintillating fiber dosimeter for radiotherapy

    NASA Astrophysics Data System (ADS)

    Bartesaghi, G.; Conti, V.; Bolognini, D.; Grigioni, S.; Mascagna, V.; Prest, M.; Scazzi, S.; Mozzanica, A.; Cappelletti, P.; Frigerio, M.; Gelosa, S.; Monti, A.; Ostinelli, A.; Giannini, G.; Vallazza, E.

    2007-10-01

    Radiotherapy, together with chemotherapy and surgery, is one of the main methods applied in the fight against cancer; in order to increase the chances of a successful radiotherapy treatment the dose delivery to the tumor and the surrounding normal tissues has to be computed with high accuracy. Traditional dosimeters are accurate but single channel (ionization chambers and diodes) or non real-time (radiographic films) devices. At present there is no device water equivalent that can perform real-time and bidimensional measurements of a dose distribution. This article describes the development of a real-time dosimeter based on scintillating fibers for photon and electron beams; the fibers are made of polystyrene, that is water equivalent and thus tissue equivalent, allowing a direct dose calculation. Three prototypes (single and multichannel) have been assembled, consisting in small scintillators coupled to white fibers that carry the light to photomultiplier tubes. In this article the prototypes and the readout electronics are described, together with the results of the measurements with electron and photon beams with energy up to 20 MeV (produced by linear accelerators Varian Clinac 1800 and 2100CD).

  1. Cerebral aneurysms following radiotherapy for medulloblastoma

    SciTech Connect

    Benson, P.J.; Sung, J.H.

    1989-04-01

    Three patients, two males and one female aged 21, 14, and 31 years, respectively, developed cerebral saccular aneurysms several years after undergoing radiotherapy for cerebellar medulloblastoma at 2, 5, and 14 years of age, respectively. Following surgery, all three received combined cobalt-60 irradiation and intrathecal colloidal radioactive gold (/sup 198/Au) therapy, and died from rupture of the aneurysm 19, 9, and 17 years after the radiotherapy, respectively. Autopsy examination revealed no recurrence of the medulloblastoma, but widespread radiation-induced vasculopathy was found at the base of the brain and in the spinal cord, and saccular aneurysms arose from the posterior cerebral arteries at the basal cistern or choroidal fissure. The aneurysms differed from the ordinary saccular aneurysms of congenital type in their location and histological features. Their locations corresponded to the areas where intrathecally administered colloidal /sup 198/Au is likely to pool, and they originated directly from a segment of the artery rather than from a branching site as in congenital saccular aneurysms. It is, therefore, concluded that the aneurysms in these three patients were most likely radiation-induced.

  2. Uses of megavoltage digital tomosynthesis in radiotherapy

    NASA Astrophysics Data System (ADS)

    Sarkar, Vikren

    With the advent of intensity modulated radiotherapy, radiation treatment plans are becoming more conformal to the tumor with the decreasing margins. It is therefore of prime importance that the patient be positioned correctly prior to treatment. Therefore, image guided treatment is necessary for intensity modulated radiotherapy plans to be implemented successfully. Current advanced imaging devices require costly hardware and software upgrade, and radiation imaging solutions, such as cone beam computed tomography, may introduce extra radiation dose to the patient in order to acquire better quality images. Thus, there is a need to extend current existing imaging device ability and functions while reducing cost and radiation dose. Existing electronic portal imaging devices can be used to generate computed tomography-like tomograms through projection images acquired over a small angle using the technique of cone-beam digital tomosynthesis. Since it uses a fraction of the images required for computed tomography reconstruction, use of this technique correspondingly delivers only a fraction of the imaging dose to the patient. Furthermore, cone-beam digital tomosynthesis can be offered as a software-only solution as long as a portal imaging device is available. In this study, the feasibility of performing digital tomosynthesis using individually-acquired megavoltage images from a charge coupled device-based electronic portal imaging device was investigated. Three digital tomosynthesis reconstruction algorithms, the shift-and-add, filtered back-projection, and simultaneous algebraic reconstruction technique, were compared considering the final image quality and radiation dose during imaging. A software platform, DART, was created using a combination of the Matlab and C++ languages. The platform allows for the registration of a reference Cone Beam Digital Tomosynthesis (CBDT) image against a daily acquired set to determine how to shift the patient prior to treatment. Finally

  3. Laryngeal sensation and pharyngeal delay time after (chemo)radiotherapy.

    PubMed

    Maruo, Takashi; Fujimoto, Yasushi; Ozawa, Kikuko; Hiramatsu, Mariko; Suzuki, Atsushi; Nishio, Naoki; Nakashima, Tsutomu

    2014-08-01

    The objective of the study was to evaluate the association between changes in laryngeal sensation and initiation of swallowing reflex or swallowing function before and after (chemo)radiotherapy. A prospective study was conducted in a tertiary referral university hospital. Thirteen patients who received (chemo)radiotherapy for treatment of laryngeal or hypopharyngeal cancer were included. Laryngeal sensation was evaluated at the tip of the epiglottis before and 1, 3 months, and 1 year after (chemo)radiotherapy. Videofluoroscopy was performed at the same time. Quantitative determinations included changes in laryngeal sensation, computed analysis of pharyngeal delay time, the distance and velocity of hyoid bone movement during the phase of hyoid excursion, and pharyngeal residue rate (the proportion of the bolus that was left as residue in the pharynx at the first swallow). Laryngeal sensation significantly deteriorated 1 month after (chemo)radiotherapy, but there was a tendency to return to pretreatment levels 1 year after treatment. Neither pharyngeal delay time nor displacement of the hyoid bone changed significantly before and after (chemo)radiotherapy. In addition, there was no significant difference in the mean velocity of hyoid bone movement and the amount of stasis in the pharynx at the first swallow before and after (chemo)radiotherapy. After (chemo)radiotherapy, laryngeal sensation deteriorated. But, in this study, videofluoroscopy showed that swallowing reflex and function were maintained.

  4. Review of hematological indices of cancer patients receiving combined chemotherapy & radiotherapy or receiving radiotherapy alone.

    PubMed

    Shahid, Saman

    2016-09-01

    We observed the outcomes of chemotherapy with radiotherapy (CR) or radiotherapy (RT) alone for cancer patients of larynx, breast, blood and brain origins through complete blood count (CBC). Following were more depressed in CR patients: mean corpuscular hemoglobin-MCH & lymphocytes-LYM, hematocrit, mean corpuscular hemoglobin concentration-MCHC, hemoglobin-HB and red blood cells-RBC. In RT patients, following were more depressed: LYM, MCH and MCHC. Overall, in all cancer patients, the lymphocytes were depressed 52%. There existed a significant difference between white blood cells and RBC in both CR and RT patients. A significant moderate negative correlation is found in HB with the dose range 30-78 (Gray) given to the CR cancer patients. More number of CBC parameters affected in patients treated with CR and RT; but in less percentage as compared to patients who treated with RT alone. The cancer patients suffered from anemia along with immune modulations from the treatments. PMID:27423975

  5. Radiotherapy for Graves' disease. The possible role of low-dose radiotherapy.

    PubMed

    Arenas, Meritxell; Sabater, Sebastià; Jiménez, Pedro Lara; Rovirosa, Àngels; Biete, Albert; Linares, Victoria; Belles, Montse; Panés, Julià

    2016-01-01

    Immunomodulatory effects of low-dose radiotherapy (LD-RT) have been used for the treatment of several benign diseases, including arthrodegenerative and inflammatory pathologies. Graves' disease is an autoimmune disease and radiotherapy (RT) is a therapeutic option for ocular complications. The dose recommended in the clinical practice is 20 Gy (2 Gy/day). We hypothesized that lower doses (<10 Gy total dose, <1 Gy/day) could results in higher efficacy if we achieved anti-inflammatory and immunomodulatory effects of LD-RT. We review current evidence on the effects of RT in the treatment of Graves' disease and the possible use of LD-RT treatment strategy. PMID:27601953

  6. Long-Term Breast Cancer Patient Outcomes After Adjuvant Radiotherapy Using Intensity-Modulated Radiotherapy or Conventional Tangential Radiotherapy

    PubMed Central

    Yang, Jen-Fu; Lee, Meei-Shyuan; Lin, Chun-Shu; Chao, Hsing-Lung; Chen, Chang-Ming; Lo, Cheng-Hsiang; Fan, Chao-Yueh; Tsao, Chih-Cheng; Huang, Wen-Yen

    2016-01-01

    Abstract The aim of the article is to analyze breast cancer patient clinical outcomes after long-term follow-up using intensity-modulated radiotherapy (IMRT) or conventional tangential radiotherapy (cRT). We retrospectively reviewed patients with stage 0–III breast cancer who received breast conserving therapy between April 2004 and December 2007. Of the 234 patients, 103 (44%) were treated with IMRT and 131 (56%) were treated with cRT. A total prescription dose of 45 to 50 Gy (1.8–2 Gy per fraction) was delivered to the whole breast. A 14 Gy boost dose was delivered in 7 fractions. The median follow-up was 8.2 years. Five of 131 (3.8%) cRT-treated patients and 2 of 103 (1.9%) IMRT-treated patients had loco-regional failure. The 8-year loco-regional failure-free survival rates were 96.7% and 97.6% (P = 0.393) in the cRT and IMRT groups, respectively, whereas the 8-year disease-free survival (DFS) rates were 91.2% and 93.1%, respectively (P = 0.243). Patients treated with IMRT developed ≥ grade 2 acute dermatitis less frequently than patients treated with cRT (40.8% vs 56.5%; P = 0.017). There were no differences in late toxicity. IMRT reduces ≥ grade 2 acute skin toxicity. Local control, DFS, and overall survival were equivalent with IMRT and cRT. IMRT can be considered a standard technique for breast cancer treatment. PMID:26986158

  7. Excellent Local Control With Stereotactic Radiotherapy Boost After External Beam Radiotherapy in Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Hara, Wendy; Loo, Billy W.; Goffinet, Don R.; Chang, Steven D.; Adler, John R.; Pinto, Harlan A.; Fee, Willard E.; Kaplan, Michael J.; Fischbein, Nancy J.; Le, Quynh-Thu

    2008-06-01

    Purpose: To determine long-term outcomes in patients receiving stereotactic radiotherapy (SRT) as a boost after external beam radiotherapy (EBRT) for locally advanced nasopharyngeal carcinoma (NPC). Methods and Materials: Eight-two patients received an SRT boost after EBRT between September 1992 and July 2006. Nine patients had T1, 30 had T2, 12 had T3, and 31 had T4 tumors. Sixteen patients had Stage II, 19 had Stage III, and 47 had Stage IV disease. Patients received 66 Gy of EBRT followed by a single-fraction SRT boost of 7-15 Gy, delivered 2-6 weeks after EBRT. Seventy patients also received cisplatin-based chemotherapy delivered concurrently with and adjuvant to radiotherapy. Results: At a median follow-up of 40.7 months (range, 6.5-144.2 months) for living patients, there was only 1 local failure in a patient with a T4 tumor. At 5 years, the freedom from local relapse rate was 98%, freedom from nodal relapse 83%, freedom from distant metastasis 68%, freedom from any relapse 67%, and overall survival 69%. Late toxicity included radiation-related retinopathy in 3, carotid aneurysm in 1, and radiographic temporal lobe necrosis in 10 patients, of whom 2 patients were symptomatic with seizures. Of 10 patients with temporal lobe necrosis, 9 had T4 tumors. Conclusion: Stereotactic radiotherapy boost after EBRT provides excellent local control for patients with NPC. Improved target delineation and dose homogeneity of radiation delivery for both EBRT and SRT is important to avoid long-term complications. Better systemic therapies for distant control are needed.

  8. Recent advancements in toxicity prediction following prostate cancer radiotherapy.

    PubMed

    Ospina, J D; Fargeas, A; Dréan, G; Simon, A; Acosta, O; de Crevoisier, R

    2015-01-01

    In external beam radiotherapy for prostate cancer limiting toxicities for dose escalation are bladder and rectum toxicities. Normal tissue complication probability models aim at quantifying the risk of developping adverse events following radiotherapy. These models, originally proposed in the context of uniform irradiation, have evolved to implementations based on the state-of-the-art classification methods which are trained using empirical data. Recently, the use of image processing techniques combined with population analysis methods has led to a new generation of models to understand the risk of normal tissue complications following radiotherapy. This paper overviews those methods in the case of prostate cancer radiation therapy and propose some lines of future research.

  9. Radiotherapy cost-calculation and its impact on capacity planning.

    PubMed

    Lievens, Yolande; Slotman, Berend Jan

    2003-08-01

    The rapid rise in health care expenses has resulted in an increased interest in the cost of treatments from a cost-effectiveness point of view for management purposes and in a reimbursement setting. The economics of radiotherapy within the global context of health care, and more specifically of cancer therapy, are discussed in this review. Furthermore, the calculation of radiotherapy costs from an institutional perspective using activity-based costing and on capacity planning in radiotherapy - at the departmental as well as at the national level - by integrating cost, epidemiological and scientifico-technological data are focused on. PMID:19807460

  10. Synergistic Effects of Gold Nanocages in Hyperthermia and Radiotherapy Treatment

    NASA Astrophysics Data System (ADS)

    Zhang, Ai-wei; Guo, Wei-hua; Qi, Ya-fei; Wang, Jian-zhen; Ma, Xiang-xing; Yu, De-xin

    2016-06-01

    Gold nanocages (GNCs) are a promising material that not only converts near infrared (NIR) light to heat for the ablation of tumors but also acts as a radiosensitizer. The combination of hyperthermia and radiotherapy has a synergistic effect that can lead to significant tumor cell necrosis. In the current study, we synthesized GNCs that offered the combined effects of hyperthermia and radiotherapy. This combination strategy resulted in increased tumor cell apoptosis and significant tumor tissue necrosis. We propose that GNCs can be used for clinical treatment and to potentially overcome resistance to radiotherapy by clearly increasing the antitumor effect.

  11. Intensity-Modulated Radiotherapy for Sinonasal Cancer: Improved Outcome Compared to Conventional Radiotherapy

    SciTech Connect

    Dirix, Piet; Vanstraelen, Bianca; Jorissen, Mark; Vander Poorten, Vincent; Nuyts, Sandra

    2010-11-15

    Purpose: To evaluate clinical outcome and toxicity of postoperative intensity-modulated radiotherapy (IMRT) for malignancies of the nasal cavity and paranasal sinuses. Methods and Materials: Between 2003 and 2008, 40 patients with cancer of the paranasal sinuses (n = 34) or nasal cavity (n = 6) received postoperative IMRT to a dose of 60 Gy (n = 21) or 66 Gy (n = 19). Treatment outcome and toxicity were retrospectively compared with that of a previous patient group (n = 41) who were also postoperatively treated to the same doses but with three-dimensional conformal radiotherapy without intensity modulation, from 1992 to 2002. Results: Median follow-up was 30 months (range, 4-74 months). Two-year local control, overall survival, and disease-free survival were 76%, 89%, and 72%, respectively. Compared to the three-dimensional conformal radiotherapy treatment, IMRT resulted in significantly improved disease-free survival (60% vs. 72%; p = 0.02). No grade 3 or 4 toxicity was reported in the IMRT group, either acute or chronic. The use of IMRT significantly reduced the incidence of acute as well as late side effects, especially regarding skin toxicity, mucositis, xerostomia, and dry-eye syndrome. Conclusions: Postoperative IMRT for sinonasal cancer significantly improves disease-free survival and reduces acute as well as late toxicity. Consequently, IMRT should be considered the standard treatment modality for malignancies of the nasal cavity and paranasal sinuses.

  12. Integrating Geriatric Assessment into Decision-Making after Prostatectomy: Adjuvant Radiotherapy, Salvage Radiotherapy, or None?

    PubMed Central

    Goineau, Aurore; d’Aillières, Bénédicte; de Decker, Laure; Supiot, Stéphane

    2015-01-01

    Despite current advancements in the field, management of older prostate cancer patients still remains a big challenge for Geriatric Oncology. The International Society of Geriatric Oncology (ISGO) has recently updated its recommendations in this area, and these have been widely adopted, notably by the European Association of Urology. This article outlines the principles that should be observed in the management of elderly patients who have recently undergone prostatectomy for malignancy or with a biochemical relapse following prostatectomy. Further therapeutic intervention should not be considered in those patients who are classified as frail in the geriatric assessment. In patients presenting better health conditions, salvage radiotherapy is to be preferred to adjuvant radiotherapy, which is only indicated in certain exceptional cases. Radiotherapy of the operative bed presents a higher risk to the elderly. Additionally, hormone therapy clearly shows higher side effects in older patients and therefore it should not be administered to asymptomatic patients. We propose a decision tree based on the ISGO recommendations, with specific modifications for patients in biochemical relapse. PMID:26528437

  13. Radiotherapy in the Era of Precision Medicine.

    PubMed

    Yard, Brian; Chie, Eui Kyu; Adams, Drew J; Peacock, Craig; Abazeed, Mohamed E

    2015-10-01

    Current predictors of radiation response are largely limited to clinical and histopathologic parameters, and extensive systematic analyses of the correlation between radiation sensitivity and genomic parameters remain lacking. In the era of precision medicine, the lack of -omic determinants of radiation response has hindered the personalization of radiation delivery to the unique characteristics of each patient׳s cancer and impeded the discovery of new therapies that can be administered concurrently with radiation therapy. The cataloging of the -omic determinants of radiation sensitivity of cancer has great potential in enhancing efficacy and limiting toxicity in the context of a new approach to precision radiotherapy. Herein, we review concepts and data that contribute to the delineation of the radiogenomic landscape of cancer.

  14. Breast cellulitis after conservative surgery and radiotherapy

    SciTech Connect

    Rescigno, J.; McCormick, B.; Brown, A.E.; Myskowski, P.L. )

    1994-04-30

    Cellulitis is a previously unreported complication of conservative surgery and radiation therapy for early stage breast cancer. Patients who presented with breast cellulitis after conservative therapy are described. Eleven patients that developed cellulitis of the breast over a 38-month period of observation are the subject of this report. Clinical characteristics of patients with cellulitis and their treatment and outcome are reported. Potential patient and treatment-related correlates for the development of cellulitis are analyzed. The risk of cellulitis persists years after initial breast cancer therapy. The clinical course of the patients was variable: some patients required aggressive, long-duration antibiotic therapy, while others had rapid resolution with antibiotics. Three patients suffered from multiple episodes of cellulitis. Patients with breast cancer treated with conservative surgery and radiotherapy are at risk for breast cellulitis. Systematic characterization of cases of cellulitis may provide insight into diagnosis, prevention, and more effective therapy for this uncommon complication. 15 refs., 1 fig., 2 tabs.

  15. Biologically Optimized Treatments for Hadron Radiotherapy

    NASA Astrophysics Data System (ADS)

    Nazaryan, Vahagn; Keppel, Cynthia; Britten, Richard; George, Jerry; Nie, Xiliang

    2008-10-01

    Near future advances in proton radiotherapy technology will increasingly require complex, conformal treatment planning. However, the current state of knowledge of the biological efficiency of proton beams may be inadequate to facilitate precision, and reduced margins. A new project at the Hampton University Proton Therapy Institute and the Eastern Virginia Medical School aims to facilitate the expected benefits of increasingly conformal treatment capabilities. Specifically, we seek to establish with measurements the biological depth dose profile of protons with incident energies in the range 62-210 MeV, and to utilize these also to provide vastly improved model algorithms for patient treatment planning based on biological, rather than simply physical, depth dose profiles. A progress report on a model for proton biological efficiency calculations as an input algorithm for treatment planning with protons will be presented. The planned measurements will be discussed.

  16. High-LET charged particle radiotherapy

    SciTech Connect

    Castro, J.R. . Research Medicine and Radiation Biophysics Div. California Univ., San Francisco, CA . Dept. of Radiation Oncology)

    1991-07-01

    The Department of Radiation Oncology at UCSF Medical Center and the Radiation Oncology Department at UC Lawrence Berkeley Laboratory have been evaluating the use of high LET charged particle radiotherapy in a Phase 1--2 research trial ongoing since 1979. In this clinical trail, 239 patients have received at least 10 Gy (physical) minimum tumor dose with neon ions, meaning that at least one-half of their total treatment was given with high-LET charged particle therapy. Ninety-one patients received all of their therapy with neon ions. Of the 239 patients irradiated, target sites included lesions in the skin, subcutaneous tissues, head and neck such as paranasal sinuses, nasopharynx and salivary glands (major and minor), skull base and juxtaspinal area, GI tract including esophagus, pancreas and biliary tract, prostate, lung, soft tissue and bone. Analysis of these patients has been carried out with a minimum followup period of 2 years.

  17. Radiotherapy With Protons And Ion Beams

    SciTech Connect

    Jaekel, Oliver

    2010-04-26

    The use of proton and ion beams has been proposed more than 60 years ago in 1946 by Robert Wilson. In 1955 the first patients were treated with proton beams in Berkeley. Since then radiotherapy with proton and ion beams has constantly been developed at research centers. Within the last decade, however, a considerable number of hospital based facilities came into operation. In this paper an overview over the basic physical and biological properties of proton and ion beams is given. The basic accelerator concepts are outlined and the design of treatment facilities is described. Then the medical physics aspects of the beam delivery, dosimetry and treatment planning are discussed before the clinical concepts are briefly reviewed.

  18. Proton beam radiotherapy of uveal melanoma

    PubMed Central

    Damato, Bertil; Kacperek, Andrzej; Errington, Doug; Heimann, Heinrich

    2013-01-01

    Proton beam radiotherapy of uveal melanoma can be administered as primary treatment, as salvage therapy for recurrent tumor, and as neoadjuvant therapy prior to surgical resection. The physical properties of proton beams make it possible to deliver high-doses of radiation to the tumor with relative sparing of adjacent tissues. This form of therapy is effective for a wider range of uveal melanoma than any other modality, providing exceptionally-high rates of local tumor control. This is particularly the case with diffuse iris melanomas, many of which are unresectable. The chances of survival, ocular conservation, visual preservation and avoidance of iatrogenic morbidity depend greatly on the tumor size, location and extent. When treating any side-effects and/or complications, it is helpful to consider whether these are the result of collateral damage or persistence of the irradiated tumor (‘toxic tumor syndrome’). PMID:24227980

  19. Mean dose to lymphocytes during radiotherapy treatments

    SciTech Connect

    Brandan, M.E.; Perez-Pastenes, M.A.; Ostrosky-Wegman, P.; Gonsebatt, M.E.; Diaz-Perches, R.

    1994-10-01

    Using a probabilistic model with parameters from four radiotherapy protocols used in Mexican hospitals for the treatment of cervical cancer, the authors have calculated the distribution of dose to cells in peripheral blood of patients. Values of the mean dose to the lymphocytes during and after a {sup 60}Co treatment are compared to estimates from an in vivo chromosome aberration study performed on five patients. Calculations indicate that the mean dose to the circulating blood is about 2% of the tumor dose, while the mean dose to recirculating lymphocytes may reach up to 7% of the tumor dose. Differences up to a factor of two in the dose to the blood are predicted for different protocols delivering equal tumor doses. The data suggest mean doses higher than the predictions of the model. 10 refs., 3 figs., 2 tabs.

  20. Radiotherapy With Protons And Ion Beams

    NASA Astrophysics Data System (ADS)

    Jäkel, Oliver

    2010-04-01

    The use of proton and ion beams has been proposed more than 60 years ago in 1946 by Robert Wilson. In 1955 the first patients were treated with proton beams in Berkeley. Since then radiotherapy with proton and ion beams has constantly been developed at research centers. Within the last decade, however, a considerable number of hospital based facilities came into operation. In this paper an overview over the basic physical and biological properties of proton and ion beams is given. The basic accelerator concepts are outlined and the design of treatment facilities is described. Then the medical physics aspects of the beam delivery, dosimetry and treatment planning are discussed before the clinical concepts are briefly reviewed.

  1. Radiotherapy Dose Fractionation under Parameter Uncertainty

    NASA Astrophysics Data System (ADS)

    Davison, Matt; Kim, Daero; Keller, Harald

    2011-11-01

    In radiotherapy, radiation is directed to damage a tumor while avoiding surrounding healthy tissue. Tradeoffs ensue because dose cannot be exactly shaped to the tumor. It is particularly important to ensure that sensitive biological structures near the tumor are not damaged more than a certain amount. Biological tissue is known to have a nonlinear response to incident radiation. The linear quadratic dose response model, which requires the specification of two clinically and experimentally observed response coefficients, is commonly used to model this effect. This model yields an optimization problem giving two different types of optimal dose sequences (fractionation schedules). Which fractionation schedule is preferred depends on the response coefficients. These coefficients are uncertainly known and may differ from patient to patient. Because of this not only the expected outcomes but also the uncertainty around these outcomes are important, and it might not be prudent to select the strategy with the best expected outcome.

  2. TOPICAL REVIEW: Anatomical imaging for radiotherapy

    NASA Astrophysics Data System (ADS)

    Evans, Philip M.

    2008-06-01

    The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of

  3. [Palliative radiotherapy for metastatic bone tumor].

    PubMed

    Yoshida, Kenji; Hiratsuka, Junichi

    2006-04-01

    Bone metastases are one of the most common conditions requiring radiation therapy today. Its main aim is relief of bone pain, prevention of pathological bone fractures as well as its healing, with anticipated effect upon improving mobility, function, and quality of life. For localized bone pain, external beam radiation therapy (EBRT) will be successful in reducing pain in some 80% of patients. However, optimal fraction dose and total doses of EBRT required for pain relief have been unknown. According to the recent reports, carbon ion radiotherapy seems to be a safe and effective modality in the management of metastatic bone tumor not eligible for conventional EBRT. For scattered painful metastases, the systemic administration of radioisotopes is thought to be effective. PMID:16582516

  4. Radiotherapy Dose Fractionation under Parameter Uncertainty

    SciTech Connect

    Davison, Matt; Kim, Daero; Keller, Harald

    2011-11-30

    In radiotherapy, radiation is directed to damage a tumor while avoiding surrounding healthy tissue. Tradeoffs ensue because dose cannot be exactly shaped to the tumor. It is particularly important to ensure that sensitive biological structures near the tumor are not damaged more than a certain amount. Biological tissue is known to have a nonlinear response to incident radiation. The linear quadratic dose response model, which requires the specification of two clinically and experimentally observed response coefficients, is commonly used to model this effect. This model yields an optimization problem giving two different types of optimal dose sequences (fractionation schedules). Which fractionation schedule is preferred depends on the response coefficients. These coefficients are uncertainly known and may differ from patient to patient. Because of this not only the expected outcomes but also the uncertainty around these outcomes are important, and it might not be prudent to select the strategy with the best expected outcome.

  5. [Indications for radiotherapy of rectal cancer].

    PubMed

    Winkler, R; Franke, H D; Dörner, A

    1990-01-01

    Surgery and radiotherapy complete each other in local control of suffering from rectal carcinoma. A radiotherapeutic effect on tumor is secured often. The adjuvant radiotherapy is the most interesting indication, though the most controversial as present too. Analysing all data and with experiences of an own irradiation study we have not any doubt that the indication is qualified for a combined therapy, if the therapeutic aim with priority is to prevent a local relapse as the most frequent and complained of form of therapeutic failure. In this problem, radical irradiation forms, as pre- and accumulating irradiation (sandwich-technique) and after-irradiation, render superior to an exclusive pre irradiation. In result of this study we practise a preirradiation of 25 Gy with immediately following operation and an accumulating irradiation to 50 Gy in proved high-risk-stage (T greater than or equal to 3 NoMo,Tx N1-3 Mo). If there is a primary local incurability by tumor invasion into the neighbourhood a pre-irradiation is done with 50 Gy and following explorative laparatomy within 4-6 weeks. Nearly 60% of these tumors become operable after that. Likewise we practise in unirradiated patients with locoregional tumor recurrence. Also here the extirpation quota of patients with general or systemic incurability, that a stoma construction is required in, we carry out a transanal tumor reduction and irradiate with 50 Gy after that. Especially this therapeutic principle has proved its worth in patients that are past eighty. Here with acceptable living quality and avoiding a stoma construction a survival can be reached that corresponds to the statistical survival of this stage of life. PMID:2101452

  6. Magnetic resonance imaging for prostate cancer radiotherapy.

    PubMed

    Dinh, Cuong V; Steenbergen, Peter; Ghobadi, Ghazaleh; Heijmink, Stijn W T J P; Pos, Floris J; Haustermans, Karin; van der Heide, Uulke A

    2016-03-01

    For radiotherapy of prostate cancer, MRI is used increasingly for delineation of the prostate gland. For focal treatment of low-risk prostate cancer or focal dose escalation for intermediate and high-risk cancer, delineation of the tumor is also required. While multi-parametric MRI is well established for detection of tumors and for staging of the disease, delineation of the tumor inside the prostate is not common practice. Guidelines, such as the PI-RADS classification, exist for tumor detection and staging, but no such guidelines are available for tumor delineation. Indeed, interobserver studies show substantial variation in tumor contours. Computer-aided tumor detection and delineation may help improve the robustness of the interpretation of multi-parametric MRI data. Comparing the performance of an earlier developed model for tumor segmentation with expert delineations, we found a significant correlation between tumor probability in a voxel and the number of experts identifying this voxel as tumor. This suggests that the model agrees with 'the wisdom of the crowd', and thus could serve as a reference for individual physicians in their decision making. With multi-parametric MRI it becomes feasible to revisit the GTV-CTV concept in radiotherapy of prostate cancer. While detection of index lesions is quite reliable, contouring variability and the low sensitivity to small lesions suggest that the remainder of the prostate should be treated as CTV. Clinical trials that investigate the options for dose differentiation, for example with dose escalation to the visible tumor or dose reduction to the CTV, are therefore warranted.

  7. Radiotherapy and temozolomide for anaplastic astrocytic gliomas

    PubMed Central

    Nayak, Lakshmi; Panageas, Katherine S.; Reiner, Anne S.; Huse, Jason T.; Pentsova, Elena; Braunthal, Stephanie G.; Abrey, Lauren E.; DeAngelis, Lisa M.

    2015-01-01

    We previously reported results of a phase II non-comparative trial that randomized patients with glioblastoma following radiotherapy to one of two different temozolomide schedules, followed by 13-cis-retinoic acid (RA) maintenance. Here we report the results of an exploratory cohort of patients accrued with anaplastic astrocytic tumors. Patients with newly diagnosed anaplastic astrocytoma (AA) or anaplastic oligo-astrocytoma (AOA) were treated with concurrent radiotherapy (60 Gy over 6 weeks) and temozolomide (75 mg/m2), and six adjuvant 28-day cycles of either dose-dense (150 mg/m2, days 1–7, 15–21) or metronomic (50 mg/m2, days 1–28) temozolomide. Subsequently, maintenance RA (100 mg/m2, days 1–21/28) was administered until disease progression. All outcome measures were descriptive without intention to compare between treatment arms. Survival was measured by the Kaplan–Meier method. There were 31 patients (21 men, 10 women) with median age 48 years (range 28–74), median KPS 90 (range 60–100). Extent of resection was gross-total in 35 %, subtotal 23 %, and biopsy 42 %. Histology was AA in 90 %, and AOA in 10 %. MGMT promoter methylation was methylated in 20 %, unmethylated in 50 %, and uninformative in 30 % of 30 tested. Median progression-free survival was 2.1 years (95 % CI 0.95–Not Reached), and overall survival 2.9 years (95 % CI 2.0–Not Reached). We report outcomes among a homogeneously treated population with anaplastic astrocytic tumors. Survival was unexpectedly short compared to other reports. These data may be useful as a contemporary historic control for other ongoing or future randomized trials. PMID:25920709

  8. Radiotherapy and temozolomide for anaplastic astrocytic gliomas.

    PubMed

    Nayak, Lakshmi; Panageas, Katherine S; Reiner, Anne S; Huse, Jason T; Pentsova, Elena; Braunthal, Stephanie G; Abrey, Lauren E; DeAngelis, Lisa M; Lassman, Andrew B

    2015-05-01

    We previously reported results of a phase II non-comparative trial that randomized patients with glioblastoma following radiotherapy to one of two different temozolomide schedules, followed by 13-cis-retinoic acid (RA) maintenance. Here we report the results of an exploratory cohort of patients accrued with anaplastic astrocytic tumors. Patients with newly diagnosed anaplastic astrocytoma (AA) or anaplastic oligo-astrocytoma (AOA) were treated with concurrent radiotherapy (60 Gy over 6 weeks) and temozolomide (75 mg/m(2)), and six adjuvant 28-day cycles of either dose-dense (150 mg/m(2), days 1-7, 15-21) or metronomic (50 mg/m(2), days 1-28) temozolomide. Subsequently, maintenance RA (100 mg/m(2), days 1-21/28) was administered until disease progression. All outcome measures were descriptive without intention to compare between treatment arms. Survival was measured by the Kaplan-Meier method. There were 31 patients (21 men, 10 women) with median age 48 years (range 28-74), median KPS 90 (range 60-100). Extent of resection was gross-total in 35%, subtotal 23%, and biopsy 42%. Histology was AA in 90%, and AOA in 10%. MGMT promoter methylation was methylated in 20%, unmethylated in 50%, and uninformative in 30% of 30 tested. Median progression-free survival was 2.1 years (95% CI 0.95-Not Reached), and overall survival 2.9 years (95 % CI 2.0-Not Reached). We report outcomes among a homogeneously treated population with anaplastic astrocytic tumors. Survival was unexpectedly short compared to other reports. These data may be useful as a contemporary historic control for other ongoing or future randomized trials. PMID:25920709

  9. Use of Postmastectomy Radiotherapy in Older Women

    SciTech Connect

    Smith, Benjamin D. Haffty, Bruce G.; Smith, Grace L.; Hurria, Arti; Buchholz, Thomas A.; Gross, Cary P.

    2008-05-01

    Purpose: Clinical trials and guidelines published between 1997 and 2001 concluded that postmastectomy radiotherapy (PMRT) improves overall survival for women with high-risk breast cancer. However, the effect of these findings on current practice is not known. Using the Surveillance, Epidemiology, and End Results-Medicare cohort, we sought to characterize the adoption of PMRT from 1992 to 2002 and identify risk factors for PMRT omission among high-risk older patients. Methods and Materials: We identified 28,973 women aged {>=}66 years who had been treated with mastectomy for invasive breast cancer between 1992 and 2002. Trends in the adoption of PMRT for low- (T1-T2N0), intermediate- (T1-T2N1), and high- (T3-T4 and/or N2-N3) risk patients were characterized using a Monte Carlo permutation algorithm. Multivariate logistic regression identified the risk factors for PMRT omission and calculated the adjusted use rates. Results: Postmastectomy radiotherapy use increased gradually and consistently for low-risk (+2.16%/y) and intermediate-risk (+7.20%/y) patients throughout the study interval. In contrast, PMRT use for high-risk patients increased sharply between 1996 and 1997 (+30.99%/y), but subsequently stabilized. Between 1998 and 2002, only 53% of high-risk patients received PMRT. The risk factors for PMRT omission included advanced age, moderate to severe comorbidity, smaller tumor size, fewer positive lymph nodes, and geographic region, with adjusted use rates ranging from 63.5% in San Francisco to 44.9% in Connecticut. Conclusion: Among the high-risk patients, PMRT use increased sharply in 1997 after the initial clinical trial publication. Despite subsequent guidelines recommending the use of PMRT, no further increase in PMRT use has occurred, and nearly 50% of high-risk patients still do not receive PMRT.

  10. Magnetic Resonance Imaging in Postprostatectomy Radiotherapy Planning

    SciTech Connect

    Sefrova, Jana; Odrazka, Karel; Paluska, Petr; Belobradek, Zdenek; Brodak, Milos; Dolezel, Martin; Prosvic, Petr; Macingova, Zuzana; Vosmik, Milan; Hoffmann, Petr; Louda, Miroslav; Nejedla, Anna

    2012-02-01

    Purpose: To investigate whether the use of magnetic resonance imaging (MRI) in prostate bed treatment planning could influence definition of the clinical target volume (CTV) and organs at risk. Methods and Materials: A total of 21 consecutive patients referred for prostate bed radiotherapy were included in the present retrospective study. The CTV was delineated according to the European Organization for Research and Treatment of Cancer recommendations on computed tomography (CT) and T{sub 1}-weighted (T{sub 1}w) and T{sub 2}-weighted (T{sub 2}w) MRI. The CTV magnitude, agreement, and spatial differences were evaluated on the planning CT scan after registration with the MRI scans. Results: The CTV was significantly reduced on the T{sub 1}w and T{sub 2}w MRI scans (13% and 9%, respectively) compared with the CT scans. The urinary bladder was drawn smaller on the CT scans and the rectum was smaller on the MRI scans. On T{sub 1}w MRI, the rectum and urinary bladder were delineated larger than on T{sub 2}w MRI. Minimal agreement was observed between the CT and T{sub 2}w images. The main spatial differences were measured in the superior and superolateral directions in which the CTV on the MRI scans was 1.8-2.9 mm smaller. In the posterior and inferior border, no difference was seen between the CT and T{sub 1}w MRI scans. On the T{sub 2}w MRI scans, the CTV was larger in these directions (by 1.3 and 1.7 mm, respectively). Conclusions: The use of MRI in postprostatectomy radiotherapy planning resulted in a reduction of the CTV. The main differences were found in the superior part of the prostate bed. We believe T{sub 2}w MRI enables more precise definition of prostate bed CTV than conventional planning CT.

  11. Targeted Radiotherapy of Estrogen Receptor Positive Tumors

    SciTech Connect

    Raghavan Rajagopalan

    2006-08-31

    The overall objectives of the proposal were to develop estrogen receptor (ER) binding small molecule radiopharmaceuticals for targeted radiotherapy of ER positive (ER+) tumors. In particular, this proposal focused on embedding a {sup 186,188}Re or a {sup 32}P radionuclide into an estrogen steroidal framework by isosteric substitution such that the resulting structure is topologically similar to the estrogen (estrogen mimic). The estrogen mimic molecules expected to bind to the ER and exhibit biodistribution akin to that of native estrogen due to structural mimicry. It is anticipated that the {sup 186,188}Re- or a {sup 32}P-containing estrogen mimics will be useful for targeted molecular radiotherapy of ER+ tumors. It is well established that the in vivo target tissue uptake of estrogen like steroidal molecules is related to the binding of the steroids to sex hormone binding globulin (SHBG). SHBG is important in the uptake of estrogens and testosterone in target tissues by SHBG receptors on the cell surface. However, hitherto the design of estrogen like small molecule radiopharmaceuticals was focused on optimizing ER binding characteristics without emphasis on SHBG binding properties. Consequently, even the molecules with good ER affinity in vitro, performed poorly in biodistribution studies. Based on molecular modeling studies the proposal focused on developing estrogen mimics 1-3 which were topologically similar to native estrogens, and form hydrogen bonds in ER and SHBG in the same manner as those of native estrogens. To this end the technical objectives of the proposal focused on synthesizing the rhenium-estrone and estradiol mimics 1 and 2 respectively, and phosphorous estradiol mimic 3 and to assess their stability and in vitro binding characteristics to ER and SHBG.

  12. Evaluation of air photoactivation at linear accelerators for radiotherapy.

    PubMed

    Tana, Luigi; Ciolini, Riccardo; Ciuffardi, Eva; Romei, Chiara; d'Errico, Francesco

    2015-06-01

    High-energy x-rays produced by radiotherapy accelerators operating at potentials above 10 MV may activate the air via (γ, n) reactions with both oxygen and nitrogen. While the activation products are relatively short-lived, personnel entering the accelerator room may inhale some radioactive air, which warrants internal dosimetry assessments. This work illustrates a method based on the use of ammonium nitrate solutions for the evaluation of photon-induced air activation and for the estimate of internal doses to radiotherapy personnel. Air activation and internal dosimetry assessments based on our method are presented for some widespread radiotherapy linear accelerator models. Our results indicate that the equivalent dose to the lungs of radiotherapy personnel is negligible for beam energies below 18 MeV.

  13. [Clinical to planning target volume margins in prostate cancer radiotherapy].

    PubMed

    Ramiandrisoa, F; Duvergé, L; Castelli, J; Nguyen, T D; Servagi-Vernat, S; de Crevoisier, R

    2016-10-01

    The knowledge of inter- and intrafraction motion and deformations of the intrapelvic target volumes (prostate, seminal vesicles, prostatectomy bed and lymph nodes) as well as the main organs at risk (bladder and rectum) allow to define rational clinical to planning target volume margins, depending on the different radiotherapy techniques and their uncertainties. In case of image-guided radiotherapy, prostate margins and seminal vesicles margins can be between 5 and 10mm. The margins around the prostatectomy bed vary from 10 to 15mm and those around the lymph node clinical target volume between 7 and 10mm. Stereotactic body radiotherapy allows lower margins, which are 3 to 5mm around the prostate. Image-guided and stereotactic body radiotherapy with adequate margins allow finally moderate or extreme hypofractionation. PMID:27614515

  14. Molecular Imaging and Radiotherapy: Theranostics for Personalized Patient Management

    PubMed Central

    Velikyan, Irina

    2012-01-01

    This theme issue presents current achievements in the development of radioactive agents, pre-clinical and clinical molecular imaging, and radiotherapy in the context of theranostics in the field of oncology. PMID:22768022

  15. [Metabolic tailoring in radiotherapy for head and neck cancer].

    PubMed

    Servagi-Vernat, S; Giraud, P

    2014-10-01

    Radiotherapy based on functional imaging consists to deliver a heterogeneity dose based on biological proprieties. This approach is termed biologically conformal radiotherapy or dose painting with biological target volume inside the gross tumor volume. Diffusion-weighted magnetic resonance imaging (MRI) and dynamic contrast-enhanced MRI can also be used to define a specific biological target volume. Three main tracers are used: ((18)F)-fluorodeoxyglucose to target the hypermetabolism, ((18)F)-fluoromizonidazole and ((18)F)- fluoroazomycin arabinoside to target areas of hypoxia. In this review, we give a practical approach to achieving a treatment-guided radiotherapy molecular and the main issues raised by this imaging technique. Despite the provision of all the technological tools to the radiotherapist, this new therapeutic approach is still evaluated in clinical studies to demonstrate a real clinical benefit compared to radiotherapy based on anatomic imaging.

  16. Adenocarcinoma of the ethmoid following radiotherapy for bilateral retinoblastoma

    SciTech Connect

    Rowe, L.D.; Lane, R.; Snow, J.B. Jr.

    1980-01-01

    Adenocarcinoma of the ethmoid sinus is rare, representing only 4 to 8% of malignancies of the paranasal sinuses. An extraordinary case of papillary adenocarcinoma of the ethmoid sinus arising 30 years following high-dose radiotherapy for bilateral retinoblastoma is presented. Second fatal mesenchymal and epithelial primaries have been described in 8.5% of patients with bilateral retinoblastomas previously treated with radiotherapy; however, papillary adenocarcinoma arising within the paranasal sinuses has not been reported. Aggressive treatment including partial maxillectomy, radical pansinusectomy, radical neck dissection followed by regional radiotherapy and systemic chemotherapy failed to prevent the development of fatal hepatic metastases. The high incidence of second fatal primary neoplasms in patients with bilateral retinoblastomas receiving radiation suggests an innate susceptibility that may add to the risk of radiotherapy.

  17. Stereotactic body radiotherapy in lung cancer: an update *

    PubMed Central

    Abreu, Carlos Eduardo Cintra Vita; Ferreira, Paula Pratti Rodrigues; de Moraes, Fabio Ynoe; Neves, Wellington Furtado Pimenta; Gadia, Rafael; Carvalho, Heloisa de Andrade

    2015-01-01

    Abstract For early-stage lung cancer, the treatment of choice is surgery. In patients who are not surgical candidates or are unwilling to undergo surgery, radiotherapy is the principal treatment option. Here, we review stereotactic body radiotherapy, a technique that has produced quite promising results in such patients and should be the treatment of choice, if available. We also present the major indications, technical aspects, results, and special situations related to the technique. PMID:26398758

  18. [Radiotherapy and implantable medical device: example of infusion pumps].

    PubMed

    Abrous-Anane, S; Benhassine, S; Lopez, S; Cristina, K; Mazeron, J-J

    2013-12-01

    Indication for radiotherapy is often questioned for patients equipped with implantable medical devices like infusion pumps as the radiation tolerance is poor or not known. We report here on the case of a patient who we treated with pelvic radiotherapy for cervical cancer and who had an infusion pump in iliac fossa. We conducted a series of tests on five identical pumps that insured that the treatment protocol is harmless to the implanted device.

  19. Radiochromic Film Dosimetry and its Applications in Radiotherapy

    SciTech Connect

    Williams, Matthew; Metcalfe, Peter

    2011-05-05

    Radiochromic film can be a fast and inexpensive means for performing accurate quantitative radiation dosimetry. The development of new radiochromic compositions that have greater dose sensitivity and fewer environmental dependencies has led to an ever increasing use of the film in radiotherapy applications. In this report the various physical and dosimetric properties of radiochromic film are presented and the strategies to adequately manage these properties when using radiochromic film for radiotherapy applications are discussed.

  20. Complete response of myeloid sarcoma with cardiac involvement to radiotherapy

    PubMed Central

    Yang, Wen-Chi; Yao, Ming; Chen, Yu-Hsuan

    2016-01-01

    We present a rare case of intracardiac myeloid sarcoma (MS) of acute myeloid leukemia (AML) and who responds completely well to low-dose radiotherapy. This 19-year-old young man initially presented with AML and received standard chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, he developed intracardiac isolated MS relapse with the presentation of exertional dyspnea and superior vena cava (SVC) syndrome 3 years later. He then received radiotherapy with 24 Gy at a 12 daily fractions using forward “field in field” intensity modulated radiotherapy technique. He dramatically had improved clinical symptoms, and complete remission was achieved one month after completing radiotherapy. Our result is in line with anecdotal case reports showed that radiotherapy with 15 Gy in 10 fractions or with 24 Gy in 12 fractions resulted in good response and less toxicity of 2 cases of MS with cardiac involvement. These results indicate that a modest radiotherapy dose, 24 Gy, achieves good local control of MS with cardiac involvement. PMID:27293853

  1. Radiotherapy for idiopathic inflammatory orbital pseudotumor. Indications and results

    SciTech Connect

    Sergott, R.C.; Glaser, J.S.; Charyulu, K.

    1981-05-01

    Supervoltage radiotherapy was used in 21 orbits of 19 patients with idiopathic inflammatory orbital pseudotumor. Seventeen orbits (15 patients) were initially treated with systemic corticosteroids, but recurrence of orbital inflammation during dosage tapering was the most frequent indication for radiotherapy. Fifteen orbits (14 patients) responded favorably, as judged by reduced proptosis, decreased lid edema and conjunctival injection, improved ocular motility, and increased visual acuity. Six orbits (five patients) did not improve with radiotherapy. Patients who were successfully treated with radiotherapy have been free of recurrence for a mean follow-up period of 25.05 months; these patients have not required further corticosteroid treatment or additional radiotherapy. Low-dose (1,000 to 2,000 rad) supervoltage radiotherapy seems to have a definite role in the management of idiopathic orbital pseudotumor in the following instances: (1) when corticosteroids fail or systemic complications are unacceptable (2) when signs and symptoms recur during decreasing corticosteroid dosage, and (3) when systemic corticosteroids are medically contraindicated.

  2. Treatment of ameloblastoma and ameloblastic carcinoma with radiotherapy.

    PubMed

    Kennedy, William R; Werning, John W; Kaye, Frederic J; Mendenhall, William M

    2016-10-01

    The purpose of this study is to report our institutional experience using radiotherapy in the treatment of ameloblastoma and ameloblastic carcinoma. Three patients with ameloblastoma and 3 patients with ameloblastic carcinoma were treated with radiotherapy alone (2 patients) or surgery and postoperative radiotherapy (4 patients) at the University of Florida between 1973 and 2007. Follow-up ranged from 4.0 to 13.1 years with a median of 7.8 years. Radiotherapy complications were scored using the Common Terminology Criteria for Adverse Events, version 4.0. Local control was achieved in 4 of the 6 patients. One patient treated with RT alone for an unresectable ameloblastoma developed a local recurrence and metastases in both the cervical lymph nodes and lungs, but had excellent response to dual BRAF/MEK inhibition with dabrafenib and trametinib. Another patient treated with surgery and postoperative radiotherapy for an ameloblastic carcinoma recurred locally without metastasis, but was not salvaged. No significant treatment-related complications were observed. For patients with local recurrence or inadequate margins after surgery, adjuvant radiotherapy provides the potential for disease control. In the setting of metastatic disease, targeted therapies may provide an additional opportunity for salvage. PMID:26796877

  3. Radiation-induced heart disease in lung cancer radiotherapy

    PubMed Central

    Ming, Xin; Feng, Yuanming; Yang, Chengwen; Wang, Wei; Wang, Ping; Deng, Jun

    2016-01-01

    Abstract Background: Radiation-induced heart disease (RIHD), which affects the patients’ prognosis with both acute and late side effects, has been published extensively in the radiotherapy of breast cancer, lymphoma and other benign diseases. Studies on RIHD in lung cancer radiotherapy, however, are less extensive and clear even though the patients with lung cancer are delivered with higher doses to the heart during radiation treatment. Methods: In this article, after extensive literature search and analysis, we reviewed the current evidence on RIHD in lung cancer patients after their radiation treatments and investigated the potential risk factors for RIHD as compared to other types of cancers. Result: Cardiac toxicity has been found highly relevant in lung cancer radiotherapy. So far, the crude incidence of cardiac complications in the lung cancer patients after radiotherapy has been up to 33%. Conclusion: The dose to the heart, the lobar location of tumor, the treatment modality, the history of heart and pulmonary disease and smoking were considered as potential risk factors for RIHD in lung cancer radiotherapy. As treatment techniques improve over the time with better prognosis for lung cancer survivors, an improved prediction model can be established to further reduce the cardiac toxicity in lung cancer radiotherapy. PMID:27741117

  4. Monte Carlo role in radiobiological modelling of radiotherapy outcomes

    NASA Astrophysics Data System (ADS)

    El Naqa, Issam; Pater, Piotr; Seuntjens, Jan

    2012-06-01

    Radiobiological models are essential components of modern radiotherapy. They are increasingly applied to optimize and evaluate the quality of different treatment planning modalities. They are frequently used in designing new radiotherapy clinical trials by estimating the expected therapeutic ratio of new protocols. In radiobiology, the therapeutic ratio is estimated from the expected gain in tumour control probability (TCP) to the risk of normal tissue complication probability (NTCP). However, estimates of TCP/NTCP are currently based on the deterministic and simplistic linear-quadratic formalism with limited prediction power when applied prospectively. Given the complex and stochastic nature of the physical, chemical and biological interactions associated with spatial and temporal radiation induced effects in living tissues, it is conjectured that methods based on Monte Carlo (MC) analysis may provide better estimates of TCP/NTCP for radiotherapy treatment planning and trial design. Indeed, over the past few decades, methods based on MC have demonstrated superior performance for accurate simulation of radiation transport, tumour growth and particle track structures; however, successful application of modelling radiobiological response and outcomes in radiotherapy is still hampered with several challenges. In this review, we provide an overview of some of the main techniques used in radiobiological modelling for radiotherapy, with focus on the MC role as a promising computational vehicle. We highlight the current challenges, issues and future potentials of the MC approach towards a comprehensive systems-based framework in radiobiological modelling for radiotherapy.

  5. Applications of Nanomaterials in Radiotherapy for Malignant Tumors.

    PubMed

    Wang, Yanchao; Liang, Ruichao; Fang, Fang

    2015-08-01

    Malignant tumors are tremendous heath problems facing by the medical world. In order to achieve the purpose of curing malignant tumor, numerous therapeutic strategies have been developed. Radiotherapy is one of the main therapeutic strategies for malignant tumors. Current imaging strategies cannot display exact infiltrating margins, radio-resistance generated by irradiated tissue, and intercurrent damage to healthy tissues during radiotherapy. Therefore, novel strategies to solve these problems are urgently needed. Nanomaterials have specific physical and biological properties that can help clinician to distinguish margins of infiltrating tumors as a novel contrast agent. Besides, nanoparticles can significantly enhance the effect of radiotherapy by generating reactive oxygen species (ROS) or influence cell cycle. In addition, nanomaterials can also help in diminishing the intercurrent damage caused by radiotherapy. So nanomaterials have very promising prospect in the radiotherapy of malignant tumors. This review mainly focuses on the applications of nanomaterials in radiotherapy for malignant tumors; especially it applies to lesion imaging and their radiosensitizing effects. PMID:26369108

  6. Nutritional consequences of the radiotherapy of head and neck cancer

    SciTech Connect

    Chencharick, J.D.; Mossman, K.L.

    1983-03-01

    Nutrition-related complications of radiotherapy were evaluated in 74 head and neck cancer patients. Subjective changes of mouth dryness, taste, dysphagia, appetite, and food preferences were determined by questionnaire before and at weekly intervals during curative radiotherapy. Changes in body weight during therapy were also recorded. In addition, 24-hour dietary histories were taken from eight patients at the beginning and end of treatment. Results of the study indicate that patients were subjectively aware of nutritional problems prior to therapy and that therapy exacerbated these problems. As many as 25% of the patients experienced oral complications such as taste loss and/or dry mouth prior to initiation of radiotherapy. By the end of radiotherapy, over 80% of the patients were aware of oral and nutritional problems. Patients had an average weight loss of 5 kg prior to therapy; this loss of weight did not change during therapy. Diet histories of eight patients indicate significant caloric deficiencies early and late in radiotherapy. The oral and nutritional problems experienced by patients, even prior to therapy, support the idea that nutritional evaluation and maintenance are important not only during therapy, but prior to radiotherapy as well. Nutritional evaluation should be made a routine, integral part of therapy for every cancer patient.

  7. Dosimetric Study of Current Treatment Options for Radiotherapy in Retinoblastoma

    SciTech Connect

    Eldebawy, Eman; Parker, William; Abdel Rahman, Wamied; Freeman, Carolyn R.

    2012-03-01

    Purpose: To determine the best treatment technique for patients with retinoblastoma requiring radiotherapy to the whole eye. Methods and Materials: Treatment plans for 3 patients with retinoblastoma were developed using 10 radiotherapy techniques including electron beams, photon beam wedge pair (WP), photon beam three-dimensional conformal radiotherapy (3D-CRT), fixed gantry intensity-modulated radiotherapy (IMRT), photon volumetric arc therapy (VMAT), fractionated stereotactic radiotherapy, and helical tomotherapy (HT). Dose-volume analyses were carried out for each technique. Results: All techniques provided similar target coverage; conformity was highest for VMAT, nine-field (9F) IMRT, and HT (conformity index [CI] = 1.3) and lowest for the WP and two electron techniques (CI = 1.8). The electron techniques had the highest planning target volume dose gradient (131% of maximum dose received [D{sub max}]), and the CRT techniques had the lowest (103% D{sub max}) gradient. The volume receiving at least 20 Gy (V{sub 20Gy}) for the ipsilateral bony orbit was lowest for the VMAT and HT techniques (56%) and highest for the CRT techniques (90%). Generally, the electron beam techniques were superior in terms of brain sparing and delivered approximately one-third of the integral dose of the photon techniques. Conclusions: Inverse planned image-guided radiotherapy delivered using HT or VMAT gives better conformity index, improved orbital bone and brain sparing, and a lower integral dose than other techniques.

  8. Complete response of myeloid sarcoma with cardiac involvement to radiotherapy.

    PubMed

    Yang, Wen-Chi; Yao, Ming; Chen, Yu-Hsuan; Kuo, Sung-Hsin

    2016-06-01

    We present a rare case of intracardiac myeloid sarcoma (MS) of acute myeloid leukemia (AML) and who responds completely well to low-dose radiotherapy. This 19-year-old young man initially presented with AML and received standard chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, he developed intracardiac isolated MS relapse with the presentation of exertional dyspnea and superior vena cava (SVC) syndrome 3 years later. He then received radiotherapy with 24 Gy at a 12 daily fractions using forward "field in field" intensity modulated radiotherapy technique. He dramatically had improved clinical symptoms, and complete remission was achieved one month after completing radiotherapy. Our result is in line with anecdotal case reports showed that radiotherapy with 15 Gy in 10 fractions or with 24 Gy in 12 fractions resulted in good response and less toxicity of 2 cases of MS with cardiac involvement. These results indicate that a modest radiotherapy dose, 24 Gy, achieves good local control of MS with cardiac involvement. PMID:27293853

  9. Radiotherapy systems using proton and carbon beams.

    PubMed

    Jongen, Y

    2008-01-01

    Radiotherapy using proton beams (proton therapy) is rapidly taking an important role among the techniques used in cancer therapy. At the end of 2007, 65.000 patients had been treated for cancer by proton beams in one of the 34 proton therapy facilities operating in the world. When compared to the now classical IMRT, and for a similar dose to the tumor, proton therapy provides a lower integral dose to the healthy organs surrounding the tumor. It is generally accepted that any reduction of the dose to healthy organs reduces the probability of radiation induced complications and of secondary malignancies. Proton therapy equipment can be obtained today from well established medical equipment companies such as Varian, Hitachi or Mitsubishi. But it is a Belgian company, Ion Beam Applications of Louvain-la-Neuve that is the undisputed leader in this market, with more than 55% of the world installed base. In addition to the now classical proton therapy equipments, using synchrotrons or cyclotrons as accelerators, new solutions have been proposed, claiming to be more compact and less expensive. A small startup company from Boston (Still Rivers) is proposing a very high magnetic field, gantry mounted superconducting synchrocyclotron. The us Company Tomotherapy is working to develop a new accelerator concept invented at Lawrence Livermore National Laboratory: the Dielectric Wall Accelerator. Besides proton beam therapy, which is progressively becoming an accepted part of radiation therapy, interest is growing for another form of radiotherapy using ions heavier than protons. Carbon ions have, even to a higher degree, the ballistic selectivity of protons. In addition, carbon ions stopping in the body exhibit a very high Linear Energy Transfer (LET). From this high LET results a very high Relative Biological Efficiency (RBE). This high RBE allows carbon ions to treat efficiently tumors who are radio-resistant and which are difficult to treat with photons or protons. The largest

  10. Cost-effectiveness of surgery plus radiotherapy versus radiotherapy alone for metastatic epidural spinal cord compression

    SciTech Connect

    Thomas, Kenneth C.; Nosyk, Bohdan; Fisher, Charles G.; Dvorak, Marcel; Patchell, Roy A.; Regine, William F.; Loblaw, Andrew; Bansback, Nick; Guh, Daphne; Sun, Huiying; Anis, Aslam . E-mail: aslam.anis@ubc.ca

    2006-11-15

    Purpose: A recent randomized clinical trial has demonstrated that direct decompressive surgery plus radiotherapy was superior to radiotherapy alone for the treatment of metastatic epidural spinal cord compression. The current study compared the cost-effectiveness of the two approaches. Methods and Materials: In the original clinical trial, clinical effectiveness was measured by ambulation and survival time until death. In this study, an incremental cost-effectiveness analysis was performed from a societal perspective. Costs related to treatment and posttreatment care were estimated and extended to the lifetime of the cohort. Weibull regression was applied to extrapolate outcomes in the presence of censored clinical effectiveness data. Results: From a societal perspective, the baseline incremental cost-effectiveness ratio (ICER) was found to be $60 per additional day of ambulation (all costs in 2003 Canadian dollars). Using probabilistic sensitivity analysis, 50% of all generated ICERs were lower than $57, and 95% were lower than $242 per additional day of ambulation. This analysis had a 95% CI of -$72.74 to 309.44, meaning that this intervention ranged from a financial savings of $72.74 to a cost of $309.44 per additional day of ambulation. Using survival as the measure of effectiveness resulted in an ICER of $30,940 per life-year gained. Conclusions: We found strong evidence that treatment of metastatic epidural spinal cord compression with surgery in addition to radiotherapy is cost-effective both in terms of cost per additional day of ambulation, and cost per life-year gained.

  11. Radiochromic film based dosimetry of image-guidance procedures on different radiotherapy modalities.

    PubMed

    Nobah, Ahmad; Aldelaijan, Saad; Devic, Slobodan; Tomic, Nada; Seuntjens, Jan; Al-Shabanah, Mohammed; Moftah, Belal

    2014-11-08

    In this work we compare doses from imaging procedures performed on today's state-of-the-art integrated imaging systems using a reference radiochromic film dosimetry system. Skin dose and dose profile measurements from different imaging systems were performed using radiochromic films at different anatomical sites on a humanoid RANDO phantom. EBT3 film was used to measure imaging doses from a TomoTherapy MVCT system, while XRQA2 film was used for dose measurements from kilovoltage imaging systems (CBCT on 21eX and TrueBeam Varian linear accelerators and CyberKnife stereoscopic orthogonal imagers). Maximum measured imaging doses in cGy at head, thorax, and pelvis regions were respectively 0.50, 1.01, and 4.91 for CBCT on 21eX, 0.38, 0.84, and 3.15 for CBCT on TrueBeam, 4.33, 3.86, and 6.50 for CyberKnife imagers, and 3.84, 1.90, and 2.09 for TomoTherapy MVCT. In addition, we have shown how an improved calibration system of XRQA2 film can achieve dose uncertainty level of better than 2% for doses above 0.25 cGy. In addition to simulation-based studies in literature, this study provides the radiation oncology team with data necessary to aid in their decision about imaging frequency for image-guided radiation therapy protocols.

  12. Planning tools for modulated electron radiotherapy

    SciTech Connect

    Surucu, Murat; Klein, Eric E.; Mamalui-Hunter, Maria; Mansur, David B.; Low, Daniel A.

    2010-05-15

    Purpose: To develop tools to plan modulated electron radiotherapy (MERT) and to compare the MERT plans to conventional or intensity modulated radiotherapy (IMRT) treatment plans. Methods: Monte Carlo dose calculations of electron fields shaped with the inherent photon multileaf collimators (MLCs) were investigated in this study. Treatment plans for four postmastectomy breast cancer patients were generated using MERT. The distances from the patient skin surfaces to the distal planning target volume surfaces were computed along the beam axis direction to determine the physical depth. Electron beam energies were selected to provide target coverage at these depths and energy bins were generated. A custom built MERT treatment planning graphical user interface (MERTgui) was used to shape the electron bins into deliverable electron segments. Monte Carlo dose distribution simulations were performed using the MLC-defined segments generated from the MERTgui. A custom built superposition gui was used to combine doses for each segment using relative weights and final MERT treatment plans were compared to the conventional or IMRT treatment plans. In addition, a demonstration of combined MERT and IMRT treatment plans was performed. Results: The MERT treatment plans provided acceptable target organ coverage in all cases. Relative to 3D conventional or IMRT treatment plans, the MERT plans predicted lower heart doses in all cases; average of the heart D{sub 20} of all plans was reduced from 14.1 to 3.3 Gy. The contralateral breast and contralateral lung doses decreased substantially with MERT planning compared to IMRT (on average, contralateral breast heart D{sub 20} was reduced from 8.7 to 0.7 Gy and contralateral lung D{sub 20} was reduced from 8.4 to 1.2 Gy with MERT). Ipsilateral lung D{sub 20} was lower with MERT than with the conventional plans (44.6 vs 29.2 Gy with MERT), but greater when compared against IMRT treatment plans (25.4 vs 28.9 Gy with MERT). A MERT and IMRT

  13. New Methods for Targeted Alpha Radiotherapy

    NASA Astrophysics Data System (ADS)

    Robertson, J. David

    2014-03-01

    Targeted radiotherapies based on alpha emitters are a promising alternative to beta emitting radionuclides. Because of their much shorter range, targeted α-radiotherapy (TAT) agents have great potential for application to small, disseminated tumors and micro metastases and treatment of hematological malignancies consisting of individual, circulating neoplastic cells. A promising approach to TAT is the use of the in vivo α-generator radionuclides 223 = 11.4 d) and 225Ac 1/2 = 10.0 d). In addition to their longer half-lives, these two isotopes have the potential of dramatically increasing the therapeutic efficacy of TAT as they each emit four α particles in their decay chain. This principle has recently been exploited in the development of Xofigo®, the first TAT agent approved for clinical use by the U.S. FDA. Xofigo, formulated as 223RaCl2, is used for treatment of metastatic bone cancer in men with castration-resistant prostate cancer. TAT with 223Ra works, however, only in the case of bone cancer because radium, as a chemical analogue of calcium, efficiently targets bone. In order to bring the benefits of TAT with 223Ra or 225Ac to other tumor types, a new delivery method must be devised. Retaining the in vivo α generator radionuclides at the target site through the decay process is one of the major challenges associated with the development of TAT. Because the recoil energy of the daughter radionuclides from the α-emission is ~ 100 keV - a value which is four orders of magnitude greater than the energy of a covalent bond - the daughters will not remain bound to the bioconjugate at the targeting site. Various approaches have been attempted to achieve retention of the α-generator daughter radionuclides at the target site, including incorporation of the in vivo generator into liposomes and fullerenes. Unfortunately, to date single wall liposomes and fullerenes are able to retain less than 10% of the daughter radionuclides. We have recently demonstrated that a

  14. Predicting radiotherapy-induced cardiac perfusion defects

    SciTech Connect

    Das, Shiva K.; Baydush, Alan H.; Zhou Sumin; Miften, Moyed; Yu Xiaoli; Craciunescu, Oana; Oldham, Mark; Light, Kim; Wong, Terence; Blazing, Michael; Borges-Neto, Salvador; Dewhirst, Mark W.; Marks, Lawrence B.

    2005-01-01

    The purpose of this work is to compare the efficacy of mathematical models in predicting the occurrence of radiotherapy-induced left ventricular perfusion defects assessed using single-photon emission computed tomography (SPECT). The basis of this study is data from 73 left-sided breast/chestwall patients treated with tangential photon fields. The mathematical models compared were three commonly used parametric models [Lyman normal tissue complication probability (LNTCP), relative serialty (RS), generalized equivalent uniform dose (gEUD)] and a nonparametric model (Linear discriminant analysis--LDA). Data used by the models were the left ventricular dose--volume histograms, or SPECT-based dose-function histograms, and the presence/absence of SPECT perfusion defects 6 months postradiation therapy (21 patients developed defects). For the parametric models, maximum likelihood estimation and F-tests were used to fit the model parameters. The nonparametric LDA model step-wise selected features (volumes/function above dose levels) using a method based on receiver operating characteristics (ROC) analysis to best separate the groups with and without defects. Optimistic (upper bound) and pessimistic (lower bound) estimates of each model's predictive capability were generated using ROC curves. A higher area under the ROC curve indicates a more accurate model (a model that is always accurate has area=1). The areas under these curves for different models were used to statistically test for differences between them. Pessimistic estimates of areas under the ROC curve using dose-volume histogram/dose-function histogram inputs, in order of increasing prediction accuracy, were LNTCP (0.79/0.75), RS (0.80/0.77), gEUD (0.81/0.78), and LDA (0.84/0.86). Only the LDA model benefited from SPECT-based regional functional information. In general, the LDA model was statistically superior to the parametric models. The LDA model selected as features the left ventricular volumes above

  15. Quantifying cognitive decrements caused by cranial radiotherapy.

    PubMed

    Christie, Lori-Ann; Acharya, Munjal M; Limoli, Charles L

    2011-01-01

    With the exception of survival, cognitive impairment stemming from the clinical management of cancer is a major factor dictating therapeutic outcome. For many patients afflicted with CNS and non-CNS malignancies, radiotherapy and chemotherapy offer the best options for disease control. These treatments however come at a cost, and nearly all cancer survivors (~11 million in the US alone as of 2006) incur some risk for developing cognitive dysfunction, with the most severe cases found in patients subjected to cranial radiotherapy (~200,000/yr) for the control of primary and metastatic brain tumors. Particularly problematic are pediatric cases, whose long-term survival plagued with marked cognitive decrements results in significant socioeconomic burdens. To date, there are still no satisfactory solutions to this significant clinical problem. We have addressed this serious health concern using transplanted stem cells to combat radiation-induced cognitive decline in athymic rats subjected to cranial irradiation. Details of the stereotaxic irradiation and the in vitro culturing and transplantation of human neural stem cells (hNSCs) can be found in our companion paper (Acharya et al., JoVE reference). Following irradiation and transplantation surgery, rats are then assessed for changes in cognition, grafted cell survival and expression of differentiation-specific markers 1 and 4-months after irradiation. To critically evaluate the success or failure of any potential intervention designed to ameliorate radiation-induced cognitive sequelae, a rigorous series of quantitative cognitive tasks must be performed. To accomplish this, we subject our animals to a suite of cognitive testing paradigms including novel place recognition, water maze, elevated plus maze and fear conditioning, in order to quantify hippocampal and non-hippocampal learning and memory. We have demonstrated the utility of these tests for quantifying specific types of cognitive decrements in irradiated animals

  16. Concomitant use of radiotherapy and two topoisomerase inhibitors to treat adult T-cell leukemia with a radiotherapy-resistant bulky disease: a case series.

    PubMed

    Obama, Kosuke

    2014-01-01

    Concomitant chemoradiotherapy is established as the standard treatment to improve the prognosis of several types of solid tumor, but has not been the general practice for hematological malignancies. Here, I report two cases of adult T-cell leukemia (ATL) with a radiotherapy-resistant bulky disease treated with concomitant radiotherapy and two topoisomerase inhibitors: etoposide (VP-16) and irinotecan (CPT-11). Patient 1 was a 78-year-old man with chemotherapy-resistant inguinal bulky mass. Radiotherapy (total 40 Gy) for this inguinal lesion was started; however, the bulky disease was found to be resistant to radiotherapy and progressed. VP-16 and CPT-11 were administered in addition to radiotherapy (after a total of 20 Gy of radiotherapy). Patient 2 was a 71-year-old man with a solitary bulky mass in left cervical lesion. Various previous chemotherapy and radiotherapy approaches had not been able to control the disease. Six months after first radiotherapy, the bulky disease rapidly progressed with the occurrence of pain. Second radiotherapy (30 Gy) was started with simultaneous administration of CPT-11 and VP-16. In both cases, the bulky disease gradually regressed and completely disappeared by the end of radiotherapy. Thus, flexible adaptation of concomitant chemoradiotherapy including two topoisomerase inhibitors may offer a potential therapeutic option for radiotherapy-resistant bulky diseases, even in hematological malignancies.

  17. Radiotherapy physics research in the UK: challenges and proposed solutions

    PubMed Central

    Mackay, R I; Burnet, N G; Green, S; Illidge, T M; Staffurth, J N

    2012-01-01

    In 2011, the Clinical and Translational Radiotherapy Research Working Group (CTRad) of the National Cancer Research Institute brought together UK radiotherapy physics leaders for a think tank meeting. Following a format that CTRad had previously and successfully used with clinical oncologists, 23 departments were asked to complete a pre-meeting evaluation of their radiotherapy physics research infrastructure and the strengths, weaknesses, opportunities and threats within their own centre. These departments were brought together with the CTRad Executive Group and research funders to discuss the current state of radiotherapy physics research, perceived barriers and possible solutions. In this Commentary, we summarise the submitted materials, presentations and discussions from the meeting and propose an action plan. It is clear that there are challenges in both funding and staffing of radiotherapy physics research. Programme and project funding streams sometimes struggle to cater for physics-led work, and increased representation on research funding bodies would be valuable. Career paths for academic radiotherapy physicists need to be examined and an academic training route identified within Modernising Scientific Careers; the introduction of formal job plans may allow greater protection of research time, and should be considered. Improved access to research facilities, including research linear accelerators, would enhance research activity and pass on developments to patients more quickly; research infrastructure could be benchmarked against centres in the UK and abroad. UK National Health Service departments wishing to undertake radiotherapy research, with its attendant added value for patients, need to develop a strategy with their partner higher education institution, and collaboration between departments may provide enhanced opportunities for funded research. PMID:22972972

  18. Radiotherapy physics research in the UK: challenges and proposed solutions.

    PubMed

    Mackay, R I; Burnet, N G; Green, S; Illidge, T M; Staffurth, J N

    2012-10-01

    In 2011, the Clinical and Translational Radiotherapy Research Working Group (CTRad) of the National Cancer Research Institute brought together UK radiotherapy physics leaders for a think tank meeting. Following a format that CTRad had previously and successfully used with clinical oncologists, 23 departments were asked to complete a pre-meeting evaluation of their radiotherapy physics research infrastructure and the strengths, weaknesses, opportunities and threats within their own centre. These departments were brought together with the CTRad Executive Group and research funders to discuss the current state of radiotherapy physics research, perceived barriers and possible solutions. In this Commentary, we summarise the submitted materials, presentations and discussions from the meeting and propose an action plan. It is clear that there are challenges in both funding and staffing of radiotherapy physics research. Programme and project funding streams sometimes struggle to cater for physics-led work, and increased representation on research funding bodies would be valuable. Career paths for academic radiotherapy physicists need to be examined and an academic training route identified within Modernising Scientific Careers; the introduction of formal job plans may allow greater protection of research time, and should be considered. Improved access to research facilities, including research linear accelerators, would enhance research activity and pass on developments to patients more quickly; research infrastructure could be benchmarked against centres in the UK and abroad. UK National Health Service departments wishing to undertake radiotherapy research, with its attendant added value for patients, need to develop a strategy with their partner higher education institution, and collaboration between departments may provide enhanced opportunities for funded research.

  19. Waiting time for radiotherapy in women with cervical cancer

    PubMed Central

    do Nascimento, Maria Isabel; Azevedo e Silva, Gulnar

    2016-01-01

    ABSTRACT OBJECTIVE To describe the waiting time for radiotherapy for patients with cervical cancer. METHODS This descriptive study was conducted with 342 cervical cancer cases that were referred to primary radiotherapy, in the Baixada Fluminense region, RJ, Southeastern Brazil, from October 1995 to August 2010. The waiting time was calculated using the recommended 60-day deadline as a parameter to obtaining the first cancer treatment and considering the date at which the diagnosis was confirmed, the date of first oncological consultation and date when the radiotherapy began. Median and proportional comparisons were made using the Kruskal Wallis and Chi-square tests. RESULTS Most of the women (72.2%) began their radiotherapy within 60 days from the diagnostic confirmation date. The median of this total waiting time was 41 days. This median worsened over the time period, going from 11 days (1995-1996) to 64 days (2009-2010). The median interval between the diagnostic confirmation and the first oncological consultation was 33 days, and between the first oncological consultation and the first radiotherapy session was four days. The median waiting time differed significantly (p = 0.003) according to different stages of the tumor, reaching 56 days, 35 days and 30 days for women whose cancers were classified up to IIA; from IIB to IIIB, and IVA-IVB, respectively. CONCLUSIONS Despite most of the women having had access to radiotherapy within the recommended 60 days, the implementation of procedures to define the stage of the tumor and to reestablish clinical conditions took a large part of this time, showing that at least one of these intervals needs to be improved. Even though the waiting times were ideal for all patients, the most advanced cases were quickly treated, which suggests that access to radiotherapy by women with cervical cancer has been reached with equity. PMID:26786473

  20. Development of three-dimensional radiotherapy techniques in breast cancer

    NASA Astrophysics Data System (ADS)

    Coles, Charlotte E.

    Radiotherapy following conservation surgery decreases local relapse and death from breast cancer. Currently, the challenge is to minimise the morbidity caused by this treatment without losing efficacy. Despite many advances in radiation techniques in other sites of the body, the majority of breast cancer patients are still planned and treated using 2-dimensional simple radiotherapy techniques. In addition, breast irradiation currently consumes 30% of the UK's radiotherapy workload. Therefore, any change to more complex treatment should be of proven benefit. The primary objective of this research is to develop and evaluate novel radiotherapy techniques to decrease irradiation of normal structures and improve localisation of the tumour bed. I have developed a forward-planned intensity modulated (IMRT) breast radiotherapy technique, which has shown improved dosimetry results compared to standard breast radiotherapy. Subsequently, I have developed and implemented a phase III randomised controlled breast IMRT trial. This National Cancer Research Network adopted trial will answer an important question regarding the clinical benefit of breast IMRT. It will provide DNA samples linked with high quality clinical outcome data, for a national translational radiogenomics study investigating variation in normal tissue toxicity. Thus, patients with significant late normal tissue side effects despite good dose homogeneity will provide the best model for finding differences due to underlying genetics. I evaluated a novel technique using high definition free-hand 3-dimensional (3D) ultrasound in a phantom study, and the results suggested that this is an accurate and reproducible method for tumour bed localisation. I then compared recognised methods of tumour bed localisation with the 3D ultrasound method in a clinical study. The 3D ultrasound technique appeared to accurately represent the shape and spatial position of the tumour cavity. This tumour bed localisation research

  1. Inflammatory breast carcinoma treated by radical radiotherapy

    SciTech Connect

    Chu, A.M.; Wood, W.C.; Doucette, J.A.

    1980-06-01

    Sixty-two patients with localized clinical inflammatory breast carcinoma were treated with curative, radical radiotherapy doses to the breast and draining lymphatics. Fifty patients have died from disease, 7 are alive with disease, and 5 are free of disease at time of reporting, thus indicating the fulminant nature of this rare form of breast cancer. Median survival is approximately 18 months. A five-year actuarial survival and relapse-free survival of 14% and 6%, respectively, are obtained. Local and regional recurrence was noted in 43 of 62 patients (69%). Twelve patients (19%) failed in the locally irradiated area only, 31 patients (50%) failed in both local, regional, and distant sites, and 14 patients (23%) failed with distant metastases only. Due to the complex dosimetry required in the treatment of breast cancer, retrospective analysis was made of actual tumor doses delivered before 1972. The breast was oftentimes calculated to receive 20 to 35% less than the stated dose. Doses in excess of 6000 rads tumor dose seem necessary since 14 of the 15 patients with persistent disesase had received less than this dose. However, once tumor exceeded 10 cm increasing dose within clinical therapeutic ranges failed to control disease, although the recurrence-free interval was somewhat prolonged. Since 1976, twice-a-day fractionation has been used in larger tumors, and this appears to have decreased the local recurrence rate to 33% (2/6) patients. Preliminary results of adjuvant multiple drug therapy appear encouraging.

  2. Systemic Targeted Alpha Radiotherapy for Cancer

    PubMed Central

    Allen, BJ

    2013-01-01

    Background: The fundamental principles of internal targeted alpha therapy forcancer were established many decades ago.The high linear energy transfer (LET) ofalpha radiation to the targeted cancer cellscauses double strand breaks in DNA. Atthe same time, the short range radiation spares adjacent normal tissues. This targeted approach complements conventional external beam radiotherapy and chemotherapy. Such therapies fail on several fronts, such as lack of control of some primary cancers (e.g. glioblastoma multiforme) and to inhibit the development of lethal metastaticcancer after successful treatment of the primary cancer. Objective: This review charts the developing role of systemic high LET, internalradiation therapy. Method: Targeted alpha therapy is a rapidly advancing experimental therapy thatholds promise to deliver high cytotoxicity to targeted cancer cells. Initially thoughtto be indicated for leukemia and micrometastases, there is now evidence that solidtumors can also be regressed. Results: Alpha therapy may be molecular or physiological in its targeting. Alphaemitting radioisotopes such as Bi-212, Bi-213, At-211 and Ac-225 are used to labelmonoclonal antibodies or proteins that target specific cancer cells. Alternatively, Radium-233 is used for palliative therapy of breast and prostate cancers because of its bone seeking properties. Conclusion: Preclinical studies and clinical trials of alpha therapy are discussedfor leukemia, lymphoma, melanoma, glioblastoma multiforme, bone metastases, ovarian cancer, pancreatic cancer and other cancers. PMID:25505750

  3. Chemically enhanced radiotherapy: visions for the future

    PubMed Central

    Susheela, Sridhar P.

    2016-01-01

    Radiotherapy (RT) is an important part of cancer management, with more than a third of all cancer cures being attributable to RT. Despite the advances in RT over the past century, the overall outcomes in a majority of malignancies are still unsatisfactory. There has been a constant endeavor to enhance the outcome of RT, and this has been in the form of altered fractionation, oxymimetic radiosensitizers, the use of concurrent chemotherapy, anti-angiogenic therapy and anti-growth factor receptor targeted therapies. This article presents a vision for the future, with emphasis upon emerging prospects which could enhance RT outcomes. Positive speculations regarding the use of immunological aspects, the use of nanoscale technology and the adoption of metronomic concurrent chemotherapy have been presented. Also, the potential with the use of low dose hyperradiosensitivity in enhancing chemotherapy outcomes too has been discussed. In this era of evidence based clinical practise, there exists a strong obsession towards the ‘present’ with ‘contempt towards the future’. Accepting the shortcomings of the existing modalities, there must be a strong zeal towards discovering better methodologies to enhance radiotherapeutic outcomes for the sake of a better future. PMID:26904574

  4. Clinical advantages of carbon-ion radiotherapy

    NASA Astrophysics Data System (ADS)

    Tsujii, Hirohiko; Kamada, Tadashi; Baba, Masayuki; Tsuji, Hiroshi; Kato, Hirotoshi; Kato, Shingo; Yamada, Shigeru; Yasuda, Shigeo; Yanagi, Takeshi; Kato, Hiroyuki; Hara, Ryusuke; Yamamoto, Naotaka; Mizoe, Junetsu

    2008-07-01

    Carbon-ion radiotherapy (C-ion RT) possesses physical and biological advantages. It was started at NIRS in 1994 using the Heavy Ion Medical Accelerator in Chiba (HIMAC); since then more than 50 protocol studies have been conducted on almost 4000 patients with a variety of tumors. Clinical experiences have demonstrated that C-ion RT is effective in such regions as the head and neck, skull base, lung, liver, prostate, bone and soft tissues, and pelvic recurrence of rectal cancer, as well as for histological types including adenocarcinoma, adenoid cystic carcinoma, malignant melanoma and various types of sarcomas, against which photon therapy could be less effective. Furthermore, when compared with photon and proton RT, a significant reduction of overall treatment time and fractions has been accomplished without enhancing toxicities. Currently, the number of irradiation sessions per patient averages 13 fractions spread over approximately three weeks. This means that in a carbon therapy facility a larger number of patients than is possible with other modalities can be treated over the same period of time.

  5. Hypnotherapy in radiotherapy patients: A randomized trial

    SciTech Connect

    Stalpers, Lukas J.A. . E-mail: l.stalpers@amc.uva.nl; Costa, Hanna C. da; Merbis, Merijn A.E.; Fortuin, Andries A.; Muller, Martin J.; Dam, Frits van

    2005-02-01

    Purpose: To determine whether hypnotherapy reduces anxiety and improves the quality of life in cancer patients undergoing curative radiotherapy (RT). Methods and materials: After providing written informed consent, 69 patients were randomized between standard curative RT alone (36 controls) and RT plus hypnotherapy (33 patients). Patients in the hypnotherapy group received hypnotherapy at the intake, before RT simulation, before the first RT session, and halfway between the RT course. Anxiety was evaluated by the State-Trait Anxiety Inventory DY-1 form at six points. Quality of life was measured by the Rand Medical Outcomes Study 36-item Health Survey (SF-36) at five points. Additionally, patients answered a questionnaire to evaluate their experience and the possible benefits of this research project. Results: No statistically significant difference was found in anxiety or quality of life between the hypnotherapy and control groups. However, significantly more patients in the hypnotherapy group indicated an improvement in mental (p < 0.05) and overall (p < 0.05) well-being. Conclusion: Hypnotherapy did not reduce anxiety or improve the quality of life in cancer patients undergoing curative RT. The absence of statistically significant differences between the two groups contrasts with the hypnotherapy patients' own sense of mental and overall well-being, which was significantly greater after hypnotherapy. It cannot be excluded that the extra attention by the hypnotherapist was responsible for this beneficial effect in the hypnotherapy group. An attention-only control group would be necessary to control for this effect.

  6. Fractionated Stereotactic Radiotherapy for Facial Nerve Schwannomas.

    PubMed

    Shi, Wenyin; Jain, Varsha; Kim, Hyun; Champ, Colin; Jain, Gaurav; Farrell, Christopher; Andrews, David W; Judy, Kevin; Liu, Haisong; Artz, Gregory; Werner-Wasik, Maria; Evans, James J

    2016-02-01

    Purpose Data on the clinical course of irradiated facial nerve schwannomas (FNS) are lacking. We evaluated fractionated stereotactic radiotherapy (FSRT) for FNS. Methods Eight consecutive patients with FNS treated at our institution between 1998 and 2011 were included. Patients were treated with FSRT to a median dose of 50.4 Gy (range: 46.8-54 Gy) in 1.8 or 2.0 Gy fractions. We report the radiographic response, symptom control, and toxicity associated with FSRT for FNS. Results The median follow-up time was 43 months (range: 10-75 months). All patients presented with symptoms including pain, tinnitus, facial asymmetry, diplopia, and hearing loss. The median tumor volume was 1.57 cc. On the most recent follow-up imaging, five patients were noted to have stable tumor size; three patients had a net reduction in tumor volume. Additionally, six patients had improvement in clinical symptoms, one patient had stable clinical findings, and one patient had worsened House-Brackmann grade due to cystic degeneration. Conclusion FSRT treatment of FNS results in excellent control of growth and symptoms with a small rate of radiation toxicity. Given the importance of maintaining facial nerve function, FSRT could be considered as a primary management modality for enlarging or symptomatic FNS. PMID:26949592

  7. A dosimetry intercomparison phantom for intraoperative radiotherapy.

    PubMed

    Armoogum, Kris; Watson, Colin

    2008-01-01

    Intraoperative radiotherapy (IORT) using very low kV x-rays is a promising new treatment modality and has proven to be effective for managing breast and neurological tumours. We have treated in excess of 75 patients using four Zeiss Intrabeam x-ray sources (XRS). To date there has been no published data of any dosimetric intercomparison of this type of x-ray source used at other cancer centres worldwide. This paper describes the design of a simple dosimetry intercomparison phantom for use with these very low kV x-ray sources. A prototype polymethyl methacrylate (PMMA) phantom has been manufactured, the dimensions of which were determined by the dimensions of the XRS, the beam energy and the attenuating properties of PMMA. The phantom is used in conjunction with Gafchromic XR Type-R film (GC-XRR) and its purpose is to measure the absorbed dose at a fixed distance from the effective point source at the tip of the XRS. The utility of this phantom is further enhanced through the use of an interlock, which eliminates the need to use the mobile gantry. We have used this phantom to conduct a qualitative dosimetric intercomparison of four Zeiss Intrabeam x-ray sources with positive results. This phantom is low cost, easy to manufacture, simple to use and could be adopted as a standard method of dosimetric intercomparison for Intrabeam x-ray sources as this mode of IORT becomes more widespread. PMID:18705612

  8. Software for 3D radiotherapy dosimetry. Validation

    NASA Astrophysics Data System (ADS)

    Kozicki, Marek; Maras, Piotr; Karwowski, Andrzej C.

    2014-08-01

    The subject of this work is polyGeVero® software (GeVero Co., Poland), which has been developed to fill the requirements of fast calculations of 3D dosimetry data with the emphasis on polymer gel dosimetry for radiotherapy. This software comprises four workspaces that have been prepared for: (i) calculating calibration curves and calibration equations, (ii) storing the calibration characteristics of the 3D dosimeters, (iii) calculating 3D dose distributions in irradiated 3D dosimeters, and (iv) comparing 3D dose distributions obtained from measurements with the aid of 3D dosimeters and calculated with the aid of treatment planning systems (TPSs). The main features and functions of the software are described in this work. Moreover, the core algorithms were validated and the results are presented. The validation was performed using the data of the new PABIGnx polymer gel dosimeter. The polyGeVero® software simplifies and greatly accelerates the calculations of raw 3D dosimetry data. It is an effective tool for fast verification of TPS-generated plans for tumor irradiation when combined with a 3D dosimeter. Consequently, the software may facilitate calculations by the 3D dosimetry community. In this work, the calibration characteristics of the PABIGnx obtained through four calibration methods: multi vial, cross beam, depth dose, and brachytherapy, are discussed as well.

  9. Online Adaptive Replanning Method for Prostate Radiotherapy

    SciTech Connect

    Ahunbay, Ergun E.; Peng Cheng; Holmes, Shannon; Godley, Andrew; Lawton, Colleen; Li, X. Allen

    2010-08-01

    Purpose: To report the application of an adaptive replanning technique for prostate cancer radiotherapy (RT), consisting of two steps: (1) segment aperture morphing (SAM), and (2) segment weight optimization (SWO), to account for interfraction variations. Methods and Materials: The new 'SAM+SWO' scheme was retroactively applied to the daily CT images acquired for 10 prostate cancer patients on a linear accelerator and CT-on-Rails combination during the course of RT. Doses generated by the SAM+SWO scheme based on the daily CT images were compared with doses generated after patient repositioning using the current planning target volume (PTV) margin (5 mm, 3 mm toward rectum) and a reduced margin (2 mm), along with full reoptimization scans based on the daily CT images to evaluate dosimetry benefits. Results: For all cases studied, the online replanning method provided significantly better target coverage when compared with repositioning with reduced PTV (13% increase in minimum prostate dose) and improved organ sparing when compared with repositioning with regular PTV (13% decrease in the generalized equivalent uniform dose of rectum). The time required to complete the online replanning process was 6 {+-} 2 minutes. Conclusion: The proposed online replanning method can be used to account for interfraction variations for prostate RT with a practically acceptable time frame (5-10 min) and with significant dosimetric benefits. On the basis of this study, the developed online replanning scheme is being implemented in the clinic for prostate RT.

  10. Automated radiotherapy treatment plan integrity verification

    SciTech Connect

    Yang Deshan; Moore, Kevin L.

    2012-03-15

    Purpose: In our clinic, physicists spend from 15 to 60 min to verify the physical and dosimetric integrity of radiotherapy plans before presentation to radiation oncology physicians for approval. The purpose of this study was to design and implement a framework to automate as many elements of this quality control (QC) step as possible. Methods: A comprehensive computer application was developed to carry out a majority of these verification tasks in the Philips PINNACLE treatment planning system (TPS). This QC tool functions based on both PINNACLE scripting elements and PERL sub-routines. The core of this technique is the method of dynamic scripting, which involves a PERL programming module that is flexible and powerful for treatment plan data handling. Run-time plan data are collected, saved into temporary files, and analyzed against standard values and predefined logical rules. The results were summarized in a hypertext markup language (HTML) report that is displayed to the user. Results: This tool has been in clinical use for over a year. The occurrence frequency of technical problems, which would cause delays and suboptimal plans, has been reduced since clinical implementation. Conclusions: In addition to drastically reducing the set of human-driven logical comparisons, this QC tool also accomplished some tasks that are otherwise either quite laborious or impractical for humans to verify, e.g., identifying conflicts amongst IMRT optimization objectives.

  11. Dosimetric comparison of intensity modulated radiotherapy techniques and standard wedged tangents for whole breast radiotherapy.

    PubMed

    Fong, Andrew; Bromley, Regina; Beat, Mardi; Vien, Din; Dineley, Jude; Morgan, Graeme

    2009-02-01

    Prior to introducing intensity modulated radiotherapy (IMRT) for whole breast radiotherapy (WBRT) into our department we undertook a comparison of the dose parameters of several IMRT techniques and standard wedged tangents (SWT). Our aim was to improve the dose distribution to the breast and to decrease the dose to organs at risk (OAR): heart, lung and contralateral breast (Contra Br). Treatment plans for 20 women (10 right-sided and 10 left-sided) previously treated with SWT for WBRT were used to compare (a) SWT; (b) electronic compensators IMRT (E-IMRT); (c) tangential beam IMRT (T-IMRT); (d) coplanar multi-field IMRT (CP-IMRT); and (e) non-coplanar multi-field IMRT (NCP-IMRT). Plans for the breast were compared for (i) dose homogeneity (DH); (ii) conformity index (CI); (iii) mean dose; (iv) maximum dose; (v) minimum dose; and dose to OAR were calculated (vi) heart; (vii) lung and (viii) Contra Br. Compared with SWT, all plans except CP-IMRT gave improvement in at least two of the seven parameters evaluated. T-IMRT and NCP-IMRT resulted in significant improvement in all parameters except DH and both gave significant reduction in doses to OAR. As on initial evaluation NCP-IMRT is likely to be too time consuming to introduce on a large scale, T-IMRT is the preferred technique for WBRT for use in our department. PMID:19453534

  12. Use of a liquid ionization chamber for stereotactic radiotherapy dosimetry.

    PubMed

    Wagner, A; Crop, F; Lacornerie, T; Vandevelde, F; Reynaert, N

    2013-04-21

    Liquid ionization chambers (LICs) offer an interesting tool in the field of small beam dosimetry, allowing better spatial resolution and reduced perturbation effects. However, some aspects remain to be addressed, such as the higher recombination and the effects from the materials of the detector. Our aim was to investigate these issues and their impact. The first step was the evaluation of the recombination effects. Measurements were performed at different SSDs to vary the dose per pulse, and the collection efficiency was obtained. The BEAMnrc code was then used to model the Cyberknife head. Finally, the liquid ionization chamber itself was modelled using the EGSnrc-based code Cavity allowing the evaluation of the influence of the volume and the chamber materials. The liquid ionization charge collection efficiency is approximately 0.98 at 1.5 mGy pulse(-1), the highest dose per pulse that we have measured. Its impact on the accuracy of output factors is less than half a per cent. The detector modelling showed a significant contribution from the graphite electrode, up to 6% for the 5 mm collimator. The dependence of the average electronic mass collision stopping power of iso-octane with beam collimation is negligible and thus has no influence on output factor measurements. Finally, the volume effect reaches 5% for the small 5 mm collimator and becomes much smaller (<0.5%) for diameters above 10 mm. LICs can effectively be used for small beam relative dosimetry as long as adequate correction factors are applied, especially for the electrode and volume effects.

  13. Use of a liquid ionization chamber for stereotactic radiotherapy dosimetry.

    PubMed

    Wagner, A; Crop, F; Lacornerie, T; Vandevelde, F; Reynaert, N

    2013-04-21

    Liquid ionization chambers (LICs) offer an interesting tool in the field of small beam dosimetry, allowing better spatial resolution and reduced perturbation effects. However, some aspects remain to be addressed, such as the higher recombination and the effects from the materials of the detector. Our aim was to investigate these issues and their impact. The first step was the evaluation of the recombination effects. Measurements were performed at different SSDs to vary the dose per pulse, and the collection efficiency was obtained. The BEAMnrc code was then used to model the Cyberknife head. Finally, the liquid ionization chamber itself was modelled using the EGSnrc-based code Cavity allowing the evaluation of the influence of the volume and the chamber materials. The liquid ionization charge collection efficiency is approximately 0.98 at 1.5 mGy pulse(-1), the highest dose per pulse that we have measured. Its impact on the accuracy of output factors is less than half a per cent. The detector modelling showed a significant contribution from the graphite electrode, up to 6% for the 5 mm collimator. The dependence of the average electronic mass collision stopping power of iso-octane with beam collimation is negligible and thus has no influence on output factor measurements. Finally, the volume effect reaches 5% for the small 5 mm collimator and becomes much smaller (<0.5%) for diameters above 10 mm. LICs can effectively be used for small beam relative dosimetry as long as adequate correction factors are applied, especially for the electrode and volume effects. PMID:23514761

  14. Radiotherapy facilities, equipment, and staffing in Poland: 2005–2011

    PubMed Central

    Reinfuss, Marian; Byrski, Edward; Malicki, Julian

    2013-01-01

    Background and purpose To evaluate the current status of radiotherapy facilities, staffing, and equipment, treatment and patients in Poland for the years 2005–2011 following implementation of the National Cancer Programme. Methods A survey was sent to the radiotherapy centres in Poland to collect data on available equipment, staffing, and treatments in the years 2005–2011. Results In 2011, 76,000 patients were treated with radiotherapy at 32 centres vs. 63,000 patients at 23 centres in 2005. Number of patients increased by 21%. In 2011, there were 453 radiation oncologists – specialists (1 in 168 patients), 325 medical physicists (1 in 215 patients), and 883 radiotherapy technicians (1 in 86 patients) vs. 320, 188, and 652, respectively, in 2005. The number of linear accelerators increased by 60%, from 70 units in 2005 to 112 in 2011. The current linac/patient ratio in Poland is 1 linac per 678 patients. Waiting times from diagnosis to the start of treatment has decreased. Conclusion Compared to 2005, there are more treatment facilities, more and better equipment (linacs), and more cancer care specialists. There are still large differences between the 16 Polish provinces in terms of equipment availability and ease of access to treatment. However, radiotherapy services in Poland have improved dramatically since the year 2005. PMID:24416548

  15. Improved outcome of nasopharyngeal carcinoma treated with conventional radiotherapy

    SciTech Connect

    Palazzi, Mauro . E-mail: mauro.palazzi@istitutotumori.mi.it; Guzzo, Marco; Tomatis, Stefano Ph.D.; Cerrotta, Annamaria; Potepan, Paolo; Quattrone, Pasquale; Cantu, Giulio

    2004-12-01

    Purpose: To describe the outcome of patients with nonmetastatic nasopharyngeal carcinoma (NPC) treated with conventional radiotherapy at a single institution. Methods and materials: From 1990 to 1999, 171 consecutive patients with NPC were treated with conventional (two-dimensional) radiotherapy. Tumor histology was undifferentiated in 82% of cases. Tumor-node-metastasis Stage (American Joint Committee on Cancer/International Union Against Cancer 1997 system) was I in 6%, II in 36%, III in 22%, and IV in 36% of patients. Mean total radiation dose was 68.4 Gy. Chemotherapy was given to 62% of the patients. The median follow-up for surviving patients was 6.3 years (range, 3.1-13.1 years). Results: The 5-year overall survival, disease-specific survival, and disease-free survival rates were 72%, 74%, and 62%, respectively. The 5-year local, regional, and distant control rates were 84%, 80%, and 83% respectively. Late effects of radiotherapy were prospectively recorded in 100 patients surviving without relapse; 44% of these patients had Grade 3 xerostomia, 33% had Grade 3 dental damage, and 11% had Grade 3 hearing loss. Conclusions: This analysis shows an improved outcome for patients treated from 1990 to 1999 compared with earlier retrospective series, despite the use of two-dimensional radiotherapy. Late toxicity, however, was substantial with conventional radiotherapy.

  16. Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy.

    PubMed

    Hidaka, Takako; Chuman, Hideki; Nao-I, Nobuhisa

    2016-01-01

    Herein, we report a case of nontraumatic bilateral rhegmatogenous retinal detachment (RRD) during external beam radiotherapy for nonocular tumor, presented as an observational case study in conjunction with a review of the relevant literature. A 65-year-old male was referred to our hospital due to bilateral RRD. He underwent a biopsy for a tumor of the left frontal lobe 4 months prior to presentation, and the tumor had been diagnosed as primary central nerve system B-cell type lymphoma. He received chemotherapy and external beam radiotherapy for 1 month. There were no traumatic episodes. Bilateral retinal detachment occurred during a series of radiotherapies. Simultaneous nontraumatic bilateral retinal detachment is rare. The effects of radiotherapy on ocular functionality, particularly in cases involving retinal adhesion and vitreous contraction, may include RRD. Thus, it is necessary to closely monitor the eyes of patients undergoing radiotherapy, particularly those undergoing surgery for retinal detachment and those with a history of photocoagulation for retinal tears, a relevant family history, or risk factors known to be associated with RRD. PMID:27462261

  17. Low-dose prophylactic craniospinal radiotherapy for intracranial germinoma

    SciTech Connect

    Schoenfeld, Gordon O.; Amdur, Robert J. . E-mail: amdurrj@ufl.edu; Schmalfuss, Ilona M.; Morris, Christopher G.; Keole, Sameer R.; Mendenhall, William M.; Marcus, Robert B.

    2006-06-01

    Purpose: To report outcomes of patients with localized intracranial germinoma treated with low-dose craniospinal irradiation (CSI) followed by a boost to the ventricular system and primary site. Methods and Materials: Thirty-one patients had pathologically confirmed intracranial germinoma and no spine metastases. Low-dose CSI was administered in 29 patients: usually 21 Gy of CSI, 9.0 Gy of ventricular boost, and a 19.5-Gy tumor boost, all at 1.5 Gy per fraction. Our neuroradiologist recorded three-dimensional tumor size on magnetic resonance images before, during, and after radiotherapy. Results: With a median follow-up of 7.0 years, 29 of 31 patients (94%) are disease free. One failure had nongerminomatous histology; the initial diagnosis was a sampling error. Of 3 patients who did not receive CSI, 1 died. No patient developed myelopathy, visual deficits, dementia, or skeletal growth problems. In locally controlled patients, tumor response according to magnetic resonance scan was nearly complete within 6 months after radiotherapy. Conclusions: Radiotherapy alone with low-dose prophylactic CSI cures almost all patients with localized intracranial germinoma. Complications are rare when the daily dose of radiotherapy is limited to 1.5 Gy and the total CSI dose to 21 Gy. Patients without a near-complete response to radiotherapy should undergo resection to rule out a nongerminomatous element.

  18. Optimization approaches for planning external beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Gozbasi, Halil Ozan

    Cancer begins when cells grow out of control as a result of damage to their DNA. These abnormal cells can invade healthy tissue and form tumors in various parts of the body. Chemotherapy, immunotherapy, surgery and radiotherapy are the most common treatment methods for cancer. According to American Cancer Society about half of the cancer patients receive a form of radiation therapy at some stage. External beam radiotherapy is delivered from outside the body and aimed at cancer cells to damage their DNA making them unable to divide and reproduce. The beams travel through the body and may damage nearby healthy tissue unless carefully planned. Therefore, the goal of treatment plan optimization is to find the best system parameters to deliver sufficient dose to target structures while avoiding damage to healthy tissue. This thesis investigates optimization approaches for two external beam radiation therapy techniques: Intensity-Modulated Radiation Therapy (IMRT) and Volumetric-Modulated Arc Therapy (VMAT). We develop automated treatment planning technology for IMRT that produces several high-quality treatment plans satisfying provided clinical requirements in a single invocation and without human guidance. A novel bi-criteria scoring based beam selection algorithm is part of the planning system and produces better plans compared to those produced using a well-known scoring-based algorithm. Our algorithm is very efficient and finds the beam configuration at least ten times faster than an exact integer programming approach. Solution times range from 2 minutes to 15 minutes which is clinically acceptable. With certain cancers, especially lung cancer, a patient's anatomy changes during treatment. These anatomical changes need to be considered in treatment planning. Fortunately, recent advances in imaging technology can provide multiple images of the treatment region taken at different points of the breathing cycle, and deformable image registration algorithms can

  19. Spinal Cord Tolerance for Stereotactic Body Radiotherapy

    SciTech Connect

    Sahgal, Arjun; Ma Lijun; Gibbs, Iris; Gerszten, Peter C.; Ryu, Sam; Soltys, Scott; Weinberg, Vivian; Wong Shun; Chang, Eric; Fowler, Jack; Larson, David A.

    2010-06-01

    Purpose: Dosimetric data are reported for five cases of radiation-induced myelopathy after stereotactic body radiotherapy (SBRT) to spinal tumors. Analysis per the biologically effective dose (BED) model was performed. Methods and Materials: Five patients with radiation myelopathy were compared to a subset of 19 patients with no radiation myelopathy post-SBRT. In all patients, the thecal sac was contoured to represent the spinal cord, and doses to the maximum point, 0.1-, 1-, 2-, and 5-cc volumes, were analyzed. The mean normalized 2-Gy-equivalent BEDs (nBEDs), calculated using an alpha/beta value of 2 for late toxicity with units Gy 2/2, were compared using the t test and analysis of variance test. Results: Radiation myelopathy was observed at the maximum point with doses of 25.6 Gy in two fractions, 30.9 Gy in three fractions, and 14.8, 13.1, and 10.6 Gy in one fraction. Overall, there was a significant interaction between patient subsets and volume based on the nBED (p = 0.0003). Given individual volumes, a significant difference was observed for the mean maximum point nBED (p = 0.01). Conclusions: The maximum point dose should be respected for spine SBRT. For single-fraction SBRT 10 Gy to a maximum point is safe, and up to five fractions an nBED of 30 to 35 Gy 2/2 to the thecal sac also poses a low risk of radiation myelopathy.

  20. Carbon ion radiotherapy of skull base chondrosarcomas

    SciTech Connect

    Schulz-Ertner, Daniela . E-mail: Daniela.Ertner@med.uni-heidelberg.de; Nikoghosyan, Anna; Hof, Holger; Didinger, Bernd; Combs, Stephanie E.; Jaekel, Oliver; Karger, Christian P.; Edler, Lutz; Debus, Juergen

    2007-01-01

    Purpose: To evaluate the effectiveness and toxicity of carbon ion radiotherapy in chondrosarcomas of the skull base. Patients and Methods: Between November 1998 and September 2005, 54 patients with low-grade and intermediate-grade chondrosarcomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft fuer Schwerionenforschung in Darmstadt, Germany. All patients had gross residual tumors after surgery. Median total dose was 60 CGE (weekly fractionation 7 x 3.0 CGE). All patients were followed prospectively in regular intervals after treatment. Local control and overall survival rates were calculated using the Kaplan-Meier method. Toxicity was assessed according to the Common Terminology Criteria (CTCAE v.3.0) and Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) score. Results: Median follow-up was 33 months (range, 3-84 months). Only 2 patients developed local recurrences. The actuarial local control rates were 96.2% and 89.8% at 3 and 4 years; overall survival was 98.2%at 5 years. Only 1 patient developed a mucositis CTCAE Grade 3; the remaining patients did not develop any acute toxicities >CTCAE Grade 2. Five patients developed minor late toxicities (RTOG/EORTC Grades 1-2), including bilateral cataract (n = 1), sensory hearing loss (n = 1), a reduction of growth hormone (n = 1), and asymptomatic radiation-induced white matter changes of the adjacent temporal lobe (n = 2). Grade 3 late toxicity occurred in 1 patient (1.9%) only. Conclusions: Carbon ion RT is an effective treatment for low- and intermediate-grade chondrosarcomas of the skull base offering high local control rates with low toxicity.

  1. Stereotactic Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma

    SciTech Connect

    Leung, T.-W.; Wong, Victy Y.W.; Tung, Stewart Y.

    2009-11-01

    Purpose: To study the treatment outcome in patients with locally recurrent nasopharyngeal carcinoma (NPC) who were treated with stereotactic radiotherapy (SRT). Methods and Materials: Thirty patients with non-metastatic, locally recurrent NPC who were treated with curative intent between 1998 and 2002 were retrospectively analyzed. The International Union Against Cancer T-stage distribution at recurrence (rT) was as follows: rT1-14, rT2-7, rT3-3, and rT4-6. All patients were treated with SRT with a daily fractional dose of 2.5-4.5 Gy (median, 3 Gy) in 8-22 fractions (median, 18 fractions). Total equivalent dose (TED) was calculated by the linear-quadratic formula without a time factor correction. Results: The 5-year actuarial overall survival rate, disease-specific survival rate, and local failure-free survival (LFFS) rate for the whole group were 40%, 41.4%, and 56.8%, respectively. The 3-year LFFS rates of rT1-2 and rT3-4 diseases were 65% and 66.7%, respectively. Seven of nine patients who received a TED <55 Gy recurred locally compared with 4 of 21 patients who received >=55 Gy. Their corresponding 5-year LFFS rates were 22.2% and 75.8% (p = 0.005). The TED was the only factor significant in affecting the local control on univariate analyses. Conclusion: SRT is an effective treatment for locally recurrent NPC. TED >=55 Gy should be given to secure a higher local control rate. The late complication rates were acceptable for patients with rT1-2 disease. For patients with rT3-4 disease, more works need to be done to further decrease the late complications.

  2. Stereotactic Body Radiotherapy for Primary Hepatocellular Carcinoma

    SciTech Connect

    Andolino, David L.; Johnson, Cynthia S.; Maluccio, Mary; Kwo, Paul; Tector, A. Joseph; Zook, Jennifer; Johnstone, Peter A.S.; Cardenes, Higinia R.

    2011-11-15

    Purpose: To evaluate the safety and efficacy of stereotactic body radiotherapy (SBRT) for the treatment of primary hepatocellular carcinoma (HCC). Methods and Materials: From 2005 to 2009, 60 patients with liver-confined HCC were treated with SBRT at the Indiana University Simon Cancer Center: 36 Child-Turcotte-Pugh (CTP) Class A and 24 CTP Class B. The median number of fractions, dose per fraction, and total dose, was 3, 14 Gy, and 44 Gy, respectively, for those with CTP Class A cirrhosis and 5, 8 Gy, and 40 Gy, respectively, for those with CTP Class B. Treatment was delivered via 6 to 12 beams and in nearly all cases was prescribed to the 80% isodose line. The records of all patients were reviewed, and treatment response was scored according to Response Evaluation Criteria in Solid Tumors v1.1. Toxicity was graded according to the Common Terminology Criteria for Adverse Events v4.0. Local control (LC), time to progression (TTP), progression-free survival (PFS), and overall survival (OS) were calculated according to the method of Kaplan and Meier. Results: The median follow-up time was 27 months, and the median tumor diameter was 3.2 cm. The 2-year LC, PFS, and OS were 90%, 48%, and 67%, respectively, with median TTP of 47.8 months. Subsequently, 23 patients underwent transplant, with a median time to transplant of 7 months. There were no {>=}Grade 3 nonhematologic toxicities. Thirteen percent of patients experienced an increase in hematologic/hepatic dysfunction greater than 1 grade, and 20% experienced progression in CTP class within 3 months of treatment. Conclusions: SBRT is a safe, effective, noninvasive option for patients with HCC {<=}6 cm. As such, SBRT should be considered when bridging to transplant or as definitive therapy for those ineligible for transplant.

  3. Pattern of radiotherapy care in Bulgaria.

    PubMed

    Hadjieva, Tatiana

    2015-01-01

    The paper reveals the changing pattern of Bulgarian Radiotherapy (RT) care after the successful implementation of 15 projects for 100 million euro under the European Regional Development Fund in Operational Programme for Regional Development 2007-2013. The project enables a total one-step modernization of 14 Bulgarian RT Centres and creation of a new one. At the end of the Programme (mid 2015), 16 new Linacs and 2 modern cobalt machines will be available together with 11 virtual CT simulators, 5 CT simulators, 1 MRI and 1 PET CT for RT planning and all dosimetry facilities needed. Such a modernization has moved Bulgarian RT forward, with 2.7 MV units per one million of population (MV/mln.inh) in comparison with 0.9 MV/mln.inh in 2012. Guild of Bulgarian Radiotherapists includes 70 doctors, 46 physicists and 10 engineers, together with 118 RTTs and 114 nurses and they all have treated 16,447 patients in 2013. Major problems are inadequate reimbursement from the monopolistic Health Insurance Fund (900 euro for 3D conformal RT and 1500 euro for IMRT); fragmentation of RT care with 1-2 MV units per Centre; no payment for patient travel expenses; need for quick and profound education of 26% of doctors and 46% of physicists without RT license, along with continuous education for all others; and resource for 5000-9000 more patients to be treated yearly by RT in order to reach 45-50% from current service of 32%. After 15 years of struggle of RT experts, finally the pattern of Bulgarian RT care at 2014-2015 is approaching the level of modern European RT. PMID:26549991

  4. The Three Dimensional Conformal Radiotherapy for Hyperkeratotic Plantar Mycosis Fungoides

    PubMed Central

    Lee, Sun Young; Kwon, Hyoung Cheol; Cho, Yong-Sun; Nam, Kyung-Hwa; Ihm, Chull-Wan

    2011-01-01

    The localized early-stage of Mycosis fungoides (MF) (stage IA-IIA) is usually treated with topical agents, such as nitrogen mustard, steroids, and phototherapy (UVB/PUVA) as first line therapy; response to these initial treatments is usually good. However, hyperkeratotic plantar lesions are clinically rare and have decreased responsiveness to topical agents. For such cases, physicians may consider local radiotherapy. Here, a case of an 18-year-old Korean woman who was treated with three-dimensional conformal radiotherapy (3D-CRT) for hyperkeratotic plantar lesions that were refractory to UVA-1, methotrexate, and topical steroids is reported. Complete remission was attained after radiotherapy. During the one-year follow-up period, there has been no evidence of disease recurrence and no chronic complications have been observed. PMID:22028574

  5. Graves disease with ophthalmopathy following radiotherapy for Hodgkin's disease

    SciTech Connect

    Jacobson, D.R.; Fleming, B.J.

    1984-12-01

    The number of patients achieving long-term survival following neck irradiation for Hodgkin's disease and other malignancies is increasing. Paralleling this increase in survivors is the development of late complications of the therapy itself. Eleven patients have previously been reported who developed Graves ophthalmopathy 18 months to seven years after receiving neck radiotherapy for nonthyroidal malignancies. The seven patients who had HLA typing were all HLA-B8 negative, despite the reported association of the HLA-B8 antigen with Graves disease. A patient who is HLA-B8 positive who developed Graves ophthalmopathy and hyperthyroidism nine years after receiving mantle radiotherapy for Hodgkin's disease is reported. It is recommended that Graves disease be included among the thyroid diseases that receive consideration during follow-up of patients who have received mantle radiotherapy.

  6. Radiotherapy for intraarticular venous malformations of the knee.

    PubMed

    Fujita, Takeshi; Okimoto, Tomoaki; Ito, Katsuyoshi; Tanabe, Masahiro; Matsunaga, Naofumi

    2014-11-01

    Intraarticular venous malformation (IAVM) of the knee is a rare vascular disease that manifests with pain, swelling, and hemarthrosis. A young man with left knee pain and swelling was admitted to our institution for the treatment of the IAVM of the left knee which was diagnosed by a local orthopedic doctor via arthroscopy. A total dose of 40 Gy of radiotherapy was delivered with a daily dose of 2.0 Gy using 6 MV X-ray beams and a linear accelerator through anteroposterior portals. Fifteen months after radiotherapy, follow-up examination using radiologic imaging showed distinct shrinkage of the venous malformations. Swelling and pain of the left knee had decreased, and range of motion of the left knee was maintained. This report describes a case involving a 38-year-old man with IAVM of the left knee in whom favorable outcomes were obtained in response to radiotherapy. PMID:25017778

  7. Radiotherapy of metastatic seminoma in the dog. Case reports

    SciTech Connect

    McDonald, R.K.; Walker, M.; Legendre, A.M.; vanEe, R.T.; Gompf, R.E.

    1988-04-01

    Four dogs with metastatic seminoma were treated with cesium 137 teleradiotherapy. Minimum total tumor dose ranged from 17 to 40 gray (Gy) and was usually given through bilateral opposing sublumbar ports in eight to ten fractions, with three fractions given weekly. The tumor regressed in all four dogs. The first dog (case 1) was free of tumor and died of non-tumor related causes at 57 months. The second dog (case 2) was free of tumor but was euthanatized at 37 months for a limb fracture. The third dog (case 3) was euthanatized for undertermined pulmonary disease 43 months after radiotherapy. The fourth dog (case 4) was euthanatized 6 months following radiotherapy because of transitional cell carcinoma and renal failure. No evidence of seminoma was found at necropsy. Radiotherapy was shown to be effective treatment for seminoma with regional metastasis.

  8. Dose factor entry and display tool for BNCT radiotherapy

    DOEpatents

    Wessol, Daniel E.; Wheeler, Floyd J.; Cook, Jeremy L.

    1999-01-01

    A system for use in Boron Neutron Capture Therapy (BNCT) radiotherapy planning where a biological distribution is calculated using a combination of conversion factors and a previously calculated physical distribution. Conversion factors are presented in a graphical spreadsheet so that a planner can easily view and modify the conversion factors. For radiotherapy in multi-component modalities, such as Fast-Neutron and BNCT, it is necessary to combine each conversion factor component to form an effective dose which is used in radiotherapy planning and evaluation. The Dose Factor Entry and Display System is designed to facilitate planner entry of appropriate conversion factors in a straightforward manner for each component. The effective isodose is then immediately computed and displayed over the appropriate background (e.g. digitized image).

  9. Could Radiotherapy Effectiveness Be Enhanced by Electromagnetic Field Treatment?

    PubMed Central

    Francisco, Artacho-Cordón; del Mar, Salinas-Asensio María; Irene, Calvente; Sandra, Ríos-Arrabal; Josefa, León; Elisa, Román-Marinetto; Nicolás, Olea; Isabel, Núñez María

    2013-01-01

    One of the main goals in radiobiology research is to enhance radiotherapy effectiveness without provoking any increase in toxicity. In this context, it has been proposed that electromagnetic fields (EMFs), known to be modulators of proliferation rate, enhancers of apoptosis and inductors of genotoxicity, might control tumor recruitment and, thus, provide therapeutic benefits. Scientific evidence shows that the effects of ionizing radiation on cellular compartments and functions are strengthened by EMF. Although little is known about the potential role of EMFs in radiotherapy (RT), the radiosensitizing effect of EMFs described in the literature could support their use to improve radiation effectiveness. Thus, we hypothesized that EMF exposure might enhance the ionizing radiation effect on tumor cells, improving the effects of RT. The aim of this paper is to review reports of the effects of EMFs in biological systems and their potential therapeutic benefits in radiotherapy. PMID:23867611

  10. Role of additional radiotherapy in advanced stages of Hodgkin's disease.

    PubMed

    Meerwaldt, J H; Coleman, C N; Fischer, R I; Lister, T A; Diehl, V

    1992-09-01

    Although radiotherapy is widely used as additional treatment following chemotherapy, its precise role has never been clearly proven. Relapses tend to occur in previously involved bulky sites. Non-randomized studies may suggest a positive effect of the addition of radiotherapy. This effect however, might also be caused by selection. Randomized studies have not resulted in a survival advantage for the patients treated with additional radiotherapy compared to no further treatment or additional chemotherapy. The SWOG study 7808 suggest a 20% benefit in remission duration for the nodular sclerosis histology subgroup. Definitive conclusions have to wait for more mature results of randomized studies including the ongoing EORTC study and the possibility to perform an overview of all studies. PMID:1280464

  11. Endometrial adenocarcinoma, adjuvant radiotherapy tailored to prognostic factors.

    PubMed

    Meerwaldt, J H; Hoekstra, C J; van Putten, W L; Tjokrowardojo, A J; Koper, P C

    1990-02-01

    The optimal adjuvant radiotherapy for surgically treated endometrial cancer has not yet been defined. We report on 389 patients treated between 1970 and 1985 with adjuvant radiotherapy. The treatment was tailored to the known prognostic factors: myometrial invasion and grade of differentiation of the tumor. Ten-year overall survival was 67%, 10-year relapse-free survival 77%; 23% relapse, of which 21% distant and 6% locoregional relapse. In a multivariate analysis, stage (pT), grade, and myometrial invasion were prognostic factors. The number of locoregional failures was very small (n = 23). This small number, the fact that radiation treatment was tailored to prognostic factors, and the absence of a nontreated control group precluded an analysis of the effect of the adjuvant irradiation. Large randomized studies with a control (no treatment) arm should be performed to determine the value of adjuvant radiotherapy. PMID:2303362

  12. Frontiers in Radiotherapy for Early-Stage Invasive Breast Cancer

    PubMed Central

    Fisher, Christine M.; Rabinovitch, Rachel

    2014-01-01

    The development of breast-conserving treatment for early-stage breast cancer is one of the most important success stories in radiation oncology in the latter half of the twentieth century. Lumpectomy followed by radiotherapy provides an appealing alternative to mastectomy for many women. In recent years, there has been a shift in clinical investigational focus toward refinements in the methods of delivering adjuvant radiotherapy that provide shorter, more convenient schedules of external-beam radiotherapy and interstitial treatment. Expedited courses of whole-breast treatment have been demonstrated to be equivalent to traditional lengthier courses in terms of tumor control and cosmetic outcome and to provide an opportunity for cost efficiencies. PMID:25113764

  13. Prostaglandin inhibitor and radiotherapy in advanced head and neck cancers

    SciTech Connect

    Pillsbury, H.C. III; Webster, W.P.; Rosenman, J.

    1986-05-01

    Radiotherapy is the usual mode of treatment for unresectable head and neck cancer. To improve cure rates, extend survival, and reduce morbidity, we use accelerated hyperfractionation radiotherapy and an adjuvant drug to inhibit prostaglandin synthesis. In this study, 19 patients received 300 rad/day of radiotherapy in two equally divided doses to a total dose averaging 6,200 rad. Either indomethacin, 25 mg, or placebo was given four times a day in a double-blind fashion during therapy. Radiation mucositis was graded as 0 to 4+; pain, nutritional status, and tumor status were monitored daily and recorded biweekly. Evaluation of the data showed delayed mucositis in the experimental group for grades 1 to 3, with a significant difference at grade 3 compared with controls. The significance of a long-term comparison of cure rates would be doubtful considering the heterogeneity of the primary sites and regional disease in this group coupled with the small size of our study.

  14. Role of additional radiotherapy in advanced stages of Hodgkin's disease.

    PubMed

    Meerwaldt, J H; Coleman, C N; Fischer, R I; Lister, T A; Diehl, V

    1992-09-01

    Although radiotherapy is widely used as additional treatment following chemotherapy, its precise role has never been clearly proven. Relapses tend to occur in previously involved bulky sites. Non-randomized studies may suggest a positive effect of the addition of radiotherapy. This effect however, might also be caused by selection. Randomized studies have not resulted in a survival advantage for the patients treated with additional radiotherapy compared to no further treatment or additional chemotherapy. The SWOG study 7808 suggest a 20% benefit in remission duration for the nodular sclerosis histology subgroup. Definitive conclusions have to wait for more mature results of randomized studies including the ongoing EORTC study and the possibility to perform an overview of all studies.

  15. Radiotherapy-induced skin reactions: prevention and cure.

    PubMed

    Morgan, Kàren

    This article describes the prophylactic use of Mepitel Film in three breast-cancer patients undergoing adjuvant radiotherapy. Each patient had significant risk factors for developing severe radiotherapy-induced skin reactions. This article details the experience encountered by these patients through their treatment courses, with observations by the review radiographers responsible for the care and support of these patients during their radiotherapy and the patients themselves. The film was found to be easy to use by the clinical team and resulted in a significant reduction in adverse side effects to the skin, with an associated improvement in patient satisfaction. There was found to be a financial benefit with the use of Mepitel Film when compared to the foam dressings often required for wound management if the patients had suffered moist desquamation. PMID:25203851

  16. Whole pelvic radiotherapy for prostate cancer using 3D conformal and intensity-modulated radiotherapy

    SciTech Connect

    Ashman, Jonathan B.; Zelefsky, Michael J. . E-mail: zelefskm@mskcc.org; Hunt, Margie S.; Leibel, Steven A.; Fuks, Zvi

    2005-11-01

    Purpose: To investigate the correlations between observed clinical morbidity and dosimetric parameters for whole pelvic radiotherapy (WPRT) for prostate cancer using either three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT). Methods and Materials: Between December 1996 and January 2002, 27 patients with prostate adenocarcinoma were treated with conformal WPRT as part of their definitive treatment. WPRT was delivered with 3D-CRT in 14 patients and with IMRT in 13 patients. For each of the patients treated with IMRT, optimized conventional two-dimensional (2D) and 3D-CRT plans were retrospectively generated for the whole pelvic phase of the treatment. Dose-volume histograms for the bowel, bladder, and rectum were compared for the three techniques. Acute toxicities were evaluated for all 27 patients, and late toxicities were evaluated for 25 patients with sufficient follow-up. Toxicities were scored according to the Radiation Therapy Oncology Group morbidity grading scales. Median follow-up was 30 months. Results: Three-dimensional-CRT resulted in a 40% relative reduction (p < 0.001) in the volume of bowel receiving 45 Gy compared with 2D, and IMRT provided a further 60% reduction relative to 3D-CRT (p < 0.001). Compared with either 2D or 3D-CRT, IMRT reduced the volume of rectum receiving 45 Gy by 90% (p < 0.001). Overall, 9 patients (33%) experienced acute Grade 2 gastrointestinal (GI) toxicity, and only 1 of these patients was treated with IMRT. Antidiarrhea medication was required for 6 patients (22%). However, 5 of these 6 patients also received chemotherapy, and none were treated with IMRT. No Grade 3 or higher acute or late GI toxicities were observed. No cases of late radiation enteritis were observed. Acute and late genitourinary toxicity did not appear significantly increased by the addition of conformal WPRT. Conclusions: Compared to conventional 2D planning, conformal planning for WPRT resulted in significant

  17. Unilateral Radiotherapy for the Treatment of Tonsil Cancer

    SciTech Connect

    Chronowski, Gregory M.; Garden, Adam S.; Morrison, William H.; Frank, Steven J.; Schwartz, David L.; Shah, Shalin J.; Beadle, Beth M.; Gunn, G. Brandon; Kupferman, Michael E.; Ang, Kian K.; Rosenthal, David I.

    2012-05-01

    Purpose: To assess, through a retrospective review, clinical outcomes of patients with squamous cell carcinoma of the tonsil treated at the M. D. Anderson Cancer Center with unilateral radiotherapy techniques that irradiate the involved tonsil region and ipsilateral neck only. Methods and Materials: Of 901 patients with newly diagnosed squamous cell carcinoma of the tonsil treated with radiotherapy at our institution, we identified 102 that were treated using unilateral radiotherapy techniques. All patients had their primary site of disease restricted to the tonsillar fossa or anterior pillar, with <1 cm involvement of the soft palate. Patients had TX (n = 17 patients), T1 (n = 52), or T2 (n = 33) disease, with Nx (n = 3), N0 (n = 33), N1 (n = 23), N2a (n = 21), or N2b (n = 22) neck disease. Results: Sixty-one patients (60%) underwent diagnostic tonsillectomy before radiotherapy. Twenty-seven patients (26%) underwent excision of a cervical lymph node or neck dissection before radiotherapy. Median follow-up for surviving patients was 38 months. Locoregional control at the primary site and ipsilateral neck was 100%. Two patients experienced contralateral nodal recurrence (2%). The 5-year overall survival and disease-free survival rates were 95% and 96%, respectively. The 5-year freedom from contralateral nodal recurrence rate was 96%. Nine patients required feeding tubes during therapy. Of the 2 patients with contralateral recurrence, 1 experienced an isolated neck recurrence and was salvaged with contralateral neck dissection only and remains alive and free of disease. The other patient presented with a contralateral base of tongue tumor and involved cervical lymph node, which may have represented a second primary tumor, and died of disease. Conclusions: Unilateral radiotherapy for patients with TX-T2, N0-N2b primary tonsil carcinoma results in high rates of disease control, with low rates of contralateral nodal failure and a low incidence of acute toxicity

  18. Vertebral compression fracture after stereotactic body radiotherapy for spinal metastases.

    PubMed

    Sahgal, Arjun; Whyne, Cari M; Ma, Lijun; Larson, David A; Fehlings, Michael G

    2013-07-01

    The use of stereotactic body radiotherapy for metastatic spinal tumours is increasing. Serious adverse events for this treatment include vertebral compression fracture (VCF) and radiation myelopathy. Although VCF is a fairly low-risk adverse event (approximately 5% risk) after conventional radiotherapy, crude risk estimates for VCF after spinal SBRT range from 11% to 39%. In this Review, we summarise the evidence and predictive factors for VCF induced by spinal SBRT, review the pathophysiology of VCF in the metastatic spine, and discuss strategies used to prevent and manage this potentially disabling complication. PMID:23816297

  19. Radiotherapy-induced skin reactions: assessment and management.

    PubMed

    Bostock, Samantha; Bryan, Julie

    Patients undergoing radiotherapy often experience a skin reaction to their treatment. In an attempt to assist clinicians in the recognition and care of these radiotherapy-induced skin reactions, an assessment and management tool has been designed for use. This patient-focused assessment tool has been distributed across the counties that the authors' trust serves. It has standardised the care of patients with these skin reactions, so that the patients can be treated with the same interventions whether they visit their GP, hospital or district nurse.

  20. The Tumour Microenvironment after Radiotherapy: Mechanisms of Resistance and Recurrence

    PubMed Central

    Barker, Holly E.; Paget, James T. E.; Khan, Aadil A.; Harrington, Kevin J.

    2016-01-01

    Radiotherapy plays a central part in curing cancer. For decades, most research on improving treatment outcomes has focussed on modulating radiation-induced biological effects on cancer cells. Recently, we have better understood that components within the tumour microenvironment have pivotal roles in determining treatment outcomes. In this Review, we describe vascular, stromal and immunological changes induced in the tumour microenvironment by irradiation and discuss how they may promote radioresistance and tumour recurrence. Subsequently, we highlight how this knowledge is guiding the development of new treatment paradigms in which biologically targeted agents will be combined with radiotherapy. PMID:26105538

  1. The use of antioxidants in radiotherapy-induced skin toxicity.

    PubMed

    Amber, Kyle T; Shiman, Michael I; Badiavas, Evangelos V

    2014-01-01

    Radiation-induced skin damage is one of the most common complications of radiotherapy. In order to combat these side effects, patients often turn to alternative therapies, which often include antioxidants. Antioxidants such as those in the polyphenol chemical class, xanthine derivatives, tocepherol, sucralfate, and ascorbate have been studied for their use in either preventing or treating radiotherapy-induced skin damage. Apart from their known role as free radical scavengers, some of these antioxidants appear to alter cytokine release affecting cutaneous and systemic changes. We review the role of antioxidants in treating and preventing radiation-induced skin damage as well as the possible complications of using such therapy.

  2. Radiotherapy for a phalanx bone metastasis of a lung adenocarcinoma.

    PubMed

    Sumodhee, Shakeel; Huchot, Eric; Peret, Gaelle; Marchal, Christian; Paganin, Fabrice; Magnin, Valerie

    2014-09-01

    Phalanx bone metastasis as the initial presenting sign of lung cancer is a rare presentation. Lung cancer is known to metastasize to the bone, but rarely to the fingers. A 61-year-old male smoker presented with pain in the left ring finger. Severe pain discouraged the patient from using his left hand. An X-ray of the left hand showed a lytic bone lesion. The patient was treated with finger radiotherapy. Analgesics were no longer needed and the patient was able to reuse his left hand in his everyday life. Palliative radiotherapy relieved our patient and improved his quality of life. PMID:25493086

  3. Radiotherapy-induced skin reactions: assessment and management.

    PubMed

    Bostock, Samantha; Bryan, Julie

    Patients undergoing radiotherapy often experience a skin reaction to their treatment. In an attempt to assist clinicians in the recognition and care of these radiotherapy-induced skin reactions, an assessment and management tool has been designed for use. This patient-focused assessment tool has been distributed across the counties that the authors' trust serves. It has standardised the care of patients with these skin reactions, so that the patients can be treated with the same interventions whether they visit their GP, hospital or district nurse. PMID:26911177

  4. Marginal Recurrence Requiring Salvage Radiotherapy After Stereotactic Body Radiotherapy for Spinal Metastases

    SciTech Connect

    Koyfman, Shlomo A.; Djemil, Toufik; Burdick, Michael J.; Woody, Neil; Balagamwala, Ehsan H.; Reddy, Chandana A.; Angelov, Lilyana; Suh, John H.; Chao, Samuel T.

    2012-05-01

    Introduction: We sought to quantify and identify risk factors associated with margin recurrence (MR) requiring salvage radiotherapy after stereotactic body radiation therapy (SBRT) for spinal metastases. Methods: We retrospectively reviewed patients with spinal metastases who were treated with single-fraction SBRT between 2006 and 2009. Gross tumor was contoured, along with either the entire associated vertebral body(ies) or the posterior elements, and included in the planning target volume. No additional margins were used. MR was defined as recurrent tumor within one vertebral level above or below the treated lesion that required salvage radiotherapy. Only patients who presented for 3-month post-SBRT follow-up were included in the analysis. Fine and Gray competing risk regression models were generated to identify variables associated with higher risks of MR. MR was plotted using cumulative incidence analysis. Results: SBRT was delivered to 208 lesions in 149 patients. Median follow-up was 8.6 months, and median survival was 12.8 months. The median prescribed dose was 14 Gy (10-16 Gy). MR occurred in 26 (12.5%) treated lesions, at a median time of 7.7 months after SBRT. Patients with paraspinal disease at the time of SBRT (20.8% vs. 7.6% of patients; p = 0.02), and those treated with <16 Gy (16.3% vs. 6.3% of patients, p = 0.14) had higher rates of MR. Both variables were associated with significantly higher risk of MR on multivariate analysis. Conclusion: SBRT for spinal metastases results in a low overall rate of MR. The presence of paraspinal disease at the time of SBRT and a dose of <16 Gy were associated with higher risks of MR.

  5. Radiation-Induced Cancers From Modern Radiotherapy Techniques: Intensity-Modulated Radiotherapy Versus Proton Therapy

    SciTech Connect

    Yoon, Myonggeun; Ahn, Sung Hwan; Kim, Jinsung; Shin, Dong Ho; Park, Sung Yong; Lee, Se Byeong; Shin, Kyung Hwan; Cho, Kwan Ho

    2010-08-01

    Purpose: To assess and compare secondary cancer risk resulting from intensity-modulated radiotherapy (IMRT) and proton therapy in patients with prostate and head-and-neck cancer. Methods and Materials: Intensity-modulated radiotherapy and proton therapy in the scattering mode were planned for 5 prostate caner patients and 5 head-and-neck cancer patients. The secondary doses during irradiation were measured using ion chamber and CR-39 detectors for IMRT and proton therapy, respectively. Organ-specific radiation-induced cancer risk was estimated by applying organ equivalent dose to dose distributions. Results: The average secondary doses of proton therapy for prostate cancer patients, measured 20-60cm from the isocenter, ranged from 0.4 mSv/Gy to 0.1 mSv/Gy. The average secondary doses of IMRT for prostate patients, however, ranged between 3 mSv/Gy and 1 mSv/Gy, approximately one order of magnitude higher than for proton therapy. Although the average secondary doses of IMRT were higher than those of proton therapy for head-and-neck cancers, these differences were not significant. Organ equivalent dose calculations showed that, for prostate cancer patients, the risk of secondary cancers in out-of-field organs, such as the stomach, lungs, and thyroid, was at least 5 times higher for IMRT than for proton therapy, whereas the difference was lower for head-and-neck cancer patients. Conclusions: Comparisons of organ-specific organ equivalent dose showed that the estimated secondary cancer risk using scattering mode in proton therapy is either significantly lower than the cases in IMRT treatment or, at least, does not exceed the risk induced by conventional IMRT treatment.

  6. Large Cohort Dose-Volume Response Analysis of Parotid Gland Function After Radiotherapy: Intensity-Modulated Versus Conventional Radiotherapy

    SciTech Connect

    Dijkema, Tim Terhaard, Chris H.J.; Roesink, Judith M.; Braam, Petra M.; Gils, Carla H. van; Moerland, Marinus A.; Raaijmakers, Cornelis P.J.

    2008-11-15

    Purpose: To compare parotid gland dose-volume response relationships in a large cohort of patients treated with intensity-modulated (IMRT) and conventional radiotherapy (CRT). Methods and materials: A total of 221 patients (64 treated with IMRT, 157 with CRT) with various head-and-neck malignancies were prospectively evaluated. The distribution of tumor subsites in both groups was unbalanced. Stimulated parotid flow rates were measured before and 6 weeks, 6 months, and 1 year after radiotherapy. Parotid gland dose-volume histograms were derived from computed tomography-based treatment planning. The normal tissue complication probability (NTCP) model proposed by Lyman was fit to the data. A complication was defined as stimulated parotid flow ratio <25% of the pretreatment flow rate. The relative risk of complications was determined for IMRT vs. CRT and adjusted for the mean parotid gland dose using Poisson regression modeling. Results: One year after radiotherapy, NTCP curves for IMRT and CRT were comparable with a TD{sub 50} (uniform dose leading to a 50% complication probability) of 38 and 40 Gy, respectively. Until 6 months after RT, corrected for mean dose, different complication probabilities existed for IMRT vs. CRT. The relative risk of a complication for IMRT vs. CRT after 6 weeks was 1.42 (95% CI 1.21-1.67), after 6 months 1.41 (95% CI; 1.12-1.77), and at 1 year 1.21 (95% CI 0.87-1.68), after correcting for mean dose. Conclusions: One year after radiotherapy, no difference existed in the mean dose-based NTCP curves for IMRT and CRT. Early after radiotherapy (up to 6 months) mean dose based (Lyman) models failed to fully describe the effects of radiotherapy on the parotid glands.

  7. Tomographic Imaging on a Cobalt Radiotherapy Machine

    NASA Astrophysics Data System (ADS)

    Marsh, Matthew Brendon

    Cancer is a global problem, and many people in low-income countries do not have access to the treatment options, such as radiation therapy, that are available in wealthy countries. Where radiation therapy is available, it is often delivered using older Co-60 equipment that has not been updated to modern standards. Previous research has indicated that an updated Co-60 radiation therapy machine could deliver treatments that are equivalent to those performed with modern linear accelerators. Among the key features of these modern treatments is a tightly conformal dose distribution-- the radiation dose is shaped in three dimensions to closely match the tumour, with minimal irradiation of surrounding normal tissues. Very accurate alignment of the patient in the beam is therefore necessary to avoid missing the tumour, so all modern radiotherapy machines include imaging systems to verify the patient's position before treatment. Imaging with the treatment beam is relatively cost-effective, as it avoids the need for a second radiation source and the associated control systems. The dose rate from a Co-60 therapy source, though, is more than an order of magnitude too high to use for computed tomography (CT) imaging of a patient. Digital tomosynthesis (DT), a limited-arc imaging method that can be thought of as a hybrid of CT and conventional radiography, allows some of the three-dimensional selectivity of CT but with shorter imaging times and a five- to fifteen-fold reduction in dose. In the present work, a prototype Co-60 DT imaging system was developed and characterized. A class of clinically useful Co-60 DT protocols has been identified, based on the filtered backprojection algorithm originally designed for CT, with images acquired over a relatively small arc. Parts of the reconstruction algorithm must be modified for the DT case, and a way to reduce the beam intensity will be necessary to reduce the imaging dose to acceptable levels. Some additional study is required to

  8. Stereotactic radiotherapy of meningiomas compressing optical pathways

    SciTech Connect

    Hamm, Klaus-Detlef . E-mail: khamm@erfurt.helios-kliniken.de; Henzel, Martin; Gross, Markus W.; Surber, Gunnar; Kleinert, Gabriele; Engenhart-Cabillic, Rita

    2006-11-15

    Purpose: Microsurgical resection is usually the treatment of choice for meningiomas, especially for those that compress the optical pathways. However, in many cases of skull-base meningiomas a high risk of neurological deficits and recurrences exist in cases where the complete tumor removal was not possible. In such cases (fractionated) stereotactic radiotherapy (SRT) can offer an alternative treatment option. We evaluated the local control rate, symptomatology, and toxicity. Patients and Methods: Between 1997 and 2003, 183 patients with skull-base meningiomas were treated with SRT, among them were 65 patients with meningiomas that compressed optical pathways (64 benign, 1 atypical). Of these 65 cases, 20 were treated with SRT only, 27 were subtotally resected before SRT, and 18 underwent multiple tumor resections before SRT. We investigated the results until 2005, with a median follow-up of 45 months (range, 22-83 months). The tumor volume (TV = gross tumor volume) ranged from 0.61 to 90.20 cc (mean, 18.9 cc). Because of the risk of new visual disturbances, the dose per fraction was either 2 or 1.8 Gy for all patients, to a total dose of 50 to 60 Gy. Results: The overall survival and the progression-free survival rates for 5 years were assessed to 100% in this patient group. To date, no progression for these meningiomas have been observed. Quantitatively, tumor shrinkage of more than 20%, or more than 2 mm in diameter, was proved in 35 of the 65 cases after SRT. In 29 of the 65 patients, at least 1 of the symptoms improved. On application of the Common Toxicity Criteria (CTC), acute toxicity (Grade 3) was seen in 1 case (worsening of conjunctivitis). Another 2 patients developed late toxicity by LENT-SOMA score, 1 x Grade 1 and 1 x Grade 3 (field of vision loss). Conclusion: As a low-risk and effective treatment option for tumor control, SRT with 1.8 to 2.0 Gy per fraction can also be recommended in case of meningiomas that compress optical pathways. An

  9. Collision prediction software for radiotherapy treatments

    SciTech Connect

    Padilla, Laura; Pearson, Erik A.; Pelizzari, Charles A.

    2015-11-15

    Purpose: This work presents a method of collision predictions for external beam radiotherapy using surface imaging. The present methodology focuses on collision prediction during treatment simulation to evaluate the clearance of a patient’s treatment position and allow for its modification if necessary. Methods: A Kinect camera (Microsoft, Redmond, WA) is used to scan the patient and immobilization devices in the treatment position at the simulator. The surface is reconstructed using the SKANECT software (Occipital, Inc., San Francisco, CA). The treatment isocenter is marked using simulated orthogonal lasers projected on the surface scan. The point cloud of this surface is then shifted to isocenter and converted from Cartesian to cylindrical coordinates. A slab models the treatment couch. A cylinder with a radius equal to the normal distance from isocenter to the collimator plate, and a height defined by the collimator diameter is used to estimate collisions. Points within the cylinder clear through a full gantry rotation with the treatment couch at 0° , while points outside of it collide. The angles of collision are reported. This methodology was experimentally verified using a mannequin positioned in an alpha cradle with both arms up. A planning CT scan of the mannequin was performed, two isocenters were marked in PINNACLE, and this information was exported to AlignRT (VisionRT, London, UK)—a surface imaging system for patient positioning. This was used to ensure accurate positioning of the mannequin in the treatment room, when available. Collision calculations were performed for the two treatment isocenters and the results compared to the collisions detected the room. The accuracy of the Kinect-Skanect surface was evaluated by comparing it to the external surface of the planning CT scan. Results: Experimental verification results showed that the predicted angles of collision matched those recorded in the room within 0.5°, in most cases (largest deviation

  10. Radiotherapy for Extramedullary Plasmacytoma of the Head and Neck

    SciTech Connect

    Creach, Kimberly M.; Foote, Robert L. Neben-Wittich, Michelle A.; Kyle, Robert A.

    2009-03-01

    Purpose: To define the effectiveness of radiotherapy in the treatment of patients with extramedullary plasmacytoma of the head and neck (EMPHN). Methods and Materials: We searched the Mayo Clinic Rochester Department of Radiation Oncology electronic Tumor Registry and identified 18 consecutive patients with a diagnosis of solitary EMPHN. Sixteen patients were treated with radiotherapy at initial diagnosis and 2 received salvage radiotherapy for local failure after surgery. Median dose administered was 50.4 Gy. Median follow-up was 6.8 years. Results: One patient (6%) developed a marginal recurrence 12 months after treatment. Six patients (33%) developed multiple myeloma (2 patients) or plasmacytomas at distant sites (4 patients) at a median of 3.1 years after diagnosis (range, 0.02 to 9.6 years). Median and 5- and 10-year overall survival rates from the date of diagnosis are 12.5 years, 88%, and 55%, respectively. Two patients (11%) developed a radiation-induced malignancy at 6.5 and 6.9 years after treatment. Conclusions: Radiotherapy provides excellent local and regional tumor control and survival in patients with EMPHN. To the best of our knowledge, this is the first report of presumed radiation-induced malignancy in this patient population.

  11. Characterization of a homemade ionization chamber for radiotherapy beams.

    PubMed

    Neves, Lucio P; Perini, Ana P; dos Santos, Gelson P; Xavier, Marcos; Khoury, Helen J; Caldas, Linda V E

    2012-07-01

    A homemade cylindrical ionization chamber was studied for routine use in therapy beams of (60)Co and X-rays. Several characterization tests were performed: leakage current, saturation, ion collection efficiency, polarity effect, stability, stabilization time, chamber orientation and energy dependence. All results obtained were within international recommendations. Therefore the homemade ionization chamber presents usefulness for routine dosimetric procedures in radiotherapy beams.

  12. Treatment of Retinoblastoma: The Role of External Beam Radiotherapy

    PubMed Central

    Park, Younghee

    2015-01-01

    The risk of radiotherapy-related secondary cancers in children with constitutional retinoblastoma 1 (RB1) mutations has led to reduced use of external beam radiotherapy (EBRT) for RB. Presently, tumor reduction with chemotherapy with or without focal surgery (chemosurgery) is most commonly undertaken; EBRT is avoided as much as possible and is considered only as the last treatment option prior to enucleation. Nevertheless, approximately 80% of patients are diagnosed at a locally advanced stage, and only 20-25% of early stage RB patients can be cured with a chemosurgery strategy. As a whole, chemotherapy fails in more than two-thirds of eyes with advanced stage disease, requiring EBRT or enucleation. Radiotherapy is still considered necessary for patients with large tumor(s) who are not candidates for chemosurgery but who have visual potential. When radiation therapy is indicated, the lowest possible radiation dose combined with systemic or local chemotherapy and focal surgery may yield the best clinical outcomes in terms of local control and treatment-related toxicity. Proton beam therapy is one EBRT method that can be used for treatment of RB and reduces the radiation dose delivered to the adjacent orbital bone while maintaining an adequate dose to the tumor. To maximize the therapeutic success of treatment of advanced RB, the possibility of integrating radiotherapy at early stages of treatment may need to be discussed by a multidisciplinary team, rather than considering EBRT as only a last treatment option. PMID:26446627

  13. INL Advanced Radiotherapy Research Program Annual Report 2004

    SciTech Connect

    James Venhuizen

    2005-06-01

    This report summarizes the activities and major accomplishments for the Idaho National Laboratory Advanced Radiotherapy Research Program for calendar year 2004. Topics covered include boron analysis in biological samples, computational dosimetry and treatment planning software development, medical neutron source development and characterization, and collaborative dosimetry studies at the RA-1 facility in Buenos Aires, Argentina.

  14. Impaired B lymphocyte reactivity in patients after radiotherapy

    SciTech Connect

    Sieber, G.; Zierach, P.; Herrmann, F.; Brust, V.J.; Ruehl, H.

    1985-04-01

    The effect of therapeutic irradiation upon B lymphocyte function was investigated in patients with various malignancies. The test system used was a reverse hemolytic plaque assay, which made it possible to study the activation and differentiation of B lymphocytes into immunoglobulin-secreting cells (ISC). Peripheral blood lymphocytes from normal individuals and patients before and after radiotherapy were stimulated in vitro with the polyclonal B cell activator pokeweed mitogen, and the number of ISC was estimated. B cell reactivity was markedly reduced in those patients who had received irradiation within the last six months. In patients in whom radiotherapy had been terminated more than 12 months before the lymphocytes were tested, B cell reactivity was comparable to that of patients prior to radiotherapy. By means of marker analyses, there was a reduction of B lymphocytes and T lymphocytes in the peripheral blood with a preponderance of T helper cells. Several mechanisms--e.g., reduced or defective B cell differentiation, altered regulatory T-helper or suppressor cell function or activation of suppressive monocytes--could be responsible for impaired B cell reactivity after radiotherapy.

  15. INEEL Advanced Radiotherapy Research Program Annual Report for 2002

    SciTech Connect

    J. R. Venhuizen

    2003-05-01

    This report summarizes the activities and major accomplishments for the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2002. Topics covered include computational dosimetry and treatment planning software development, medical neutron source development and characterization, and boron analytical chemistry.

  16. INEEL Advanced Radiotherapy Research Program Annual Report 2002

    SciTech Connect

    Venhuizen, J.R.

    2003-05-23

    This report summarizes the activities and major accomplishments for the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2002. Topics covered include computational dosimetry and treatment planning software development, medical neutron source development and characterization, and boron analytical chemistry.

  17. Second neoplasms following radiotherapy or chemotherapy for cancer

    SciTech Connect

    Penn, I.

    1982-02-01

    While radiotherapy and antineoplastic chemotherapy often control malignancies they may, paradoxically, cause new cancers to develop as long-term complications. Although almost any type of neoplasm can occur, radiation-induced malignancies are most likely to affect the myelopoietic tissues and the thyroid gland. The former tissues are also most frequently involved by chemotherapy. The combination of intensive radiotherapy and intensive chemotherapy is particularly leukemogenic. Acute myeloid leukemia has occurred with increased frequency following treatment of Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, ovarian cancer, polycythemia vera, carcinoma of the thyroid gland, and carcinoma of the breast. Radiation-induced malignancies usually occur in the field of irradiation. Tumors developing in an irradiated field include a substantial number of soft tissue sarcomas or osteosarcomas. There is a 20-fold increase of second cancers following treatment of childhood malignancies, mostly sarcomas of bone and soft tissues, but including leukemia, and carcinomas of the thyroid gland, skin, and breast. The latent period between radiotherapy and the appearance of a second cancer ranges from 2 years to several decades, often being 10-15 years. With chemotherapy the mean latent period is shorter, approximately 4 years. The mechanism of oncogenesis by radiotherapy or chemotherapy is poorly understood and probably involves a complex interplay of somatic mutation, co-oncogenic effects, depression of host immunity, stimulation of cellular proliferation, and genetic susceptibility.

  18. Second primary tumors following radiotherapy for childhood cancer

    SciTech Connect

    Hawkins, M.M. )

    1990-11-01

    Among a cohort of 9,279 survivors of childhood neoplasms other than retinoblastoma treated in Britain before 1980, the cumulative risk of a second primary tumor (SPT) by 25 years from 3-year survival was 3.7%. This corresponds to about five times the number expected from rates of cancer occurring in the general population. In the absence of both radiotherapy and chemotherapy, there was four times the expected number of subsequent cancers. The risk of an SPT associated with radiotherapy but not chemotherapy and both radiotherapy and chemotherapy were 6 and 9 times that expected, respectively. There is evidence that radiotherapy was involved in the development of many of the SPT's observed. However, case-control investigations are required to examine the relationship between relative risk of an SPT and therapy in detail. Secondary leukemia appears to occur more frequently among more recently diagnosed children with cancer. It is important to continue to monitor the occurrence of SPT's with a view to identifying the least carcinogenic therapies that are consistent with not compromising survival prospects.

  19. Boost in radiotherapy: external beam sunset, brachytherapy sunrise

    PubMed Central

    2009-01-01

    Radiobiological limitations for dose escalation in external radiotherapy are presented. Biological and clinical concept of brachytherapy boost to increase treatment efficacy is discussed, and different methods are compared. Oncentra Prostate 3D conformal real-time ultrasound-guided brachytherapy is presented as a solution for boost or sole therapy.

  20. Response of lymphangiectasis to radiotherapy. [X-ray

    SciTech Connect

    Kurczynski, E.; Horwitz, S.J.

    1981-07-15

    A 14-year-old girl with lymphangiectasis of the skull causing rapid extensive destruction of the left orbit, zygoma, mandible, sphenoid, and occiput underwent radiotherapy with 2000 rad to the entire skull, mandible, and upper cervical vertebrae. Three years later, progression of the disease has ceased, and the involved bone is slowly remineralizing.

  1. Radiotherapy-related intracranial aneurysms: A role for conservative management

    PubMed Central

    Parag, Sayal; Arif, Zafar; Chittoor, Rajaraman

    2016-01-01

    Background: Radiotherapy-related intracranial aneurysms are a recognized but rare phenomenon and often present following rupture leading to subarachnoid hemorrhage. Treatment poses a particular dilemma and both endovascular, and surgical approaches have been used with varied success. We present the case of a radiotherapy-related aneurysm treated conservatively with a favorable outcome. Case Description: A 37-year-old man was diagnosed with a left temporal lobe mass for which he underwent an uneventful craniotomy and debulking. Histology revealed Grade III anaplastic astrocytoma following which he received radiotherapy. Three years later, he presented with subacute headache and transient dysphasia. Computed tomography and catheter angiography revealed a fusiform aneurysm of the supramarginal branch of the left middle cerebral artery with probable intra-aneurysmal thrombus. Adjacent vessels also showed mild vasculitic changes. Trial balloon occlusion of the parent vessel resulted in profound dysphasia and was therefore abandoned. Bypass surgery or stent placement was deemed to have too high a risk of neurological deficit, and keeping in mind, the diagnosis of anaplastic astrocytoma, conservative management was pursued with partial thrombosis noted on serial imaging and stable appearances subsequently at 42 months’ follow-up. Conclusion: Conservative management can be pursued in selective cases of radiotherapy-related aneurysms, particularly if the risk of treating is too high and in the context of intracranial malignancy with limited lifespan. PMID:27313964

  2. [New techniques and potential benefits for radiotherapy of lung cancer].

    PubMed

    Lefebvre, L; Doré, M; Giraud, P

    2014-10-01

    Radiotherapy is used for inoperable lung cancers, sometimes in association with chemotherapy. Outcomes of conventional radiotherapy are disappointing. New techniques improve adaptation to tumour volume, decrease normal tissue irradiation and lead to increasing tumour dose with the opportunity for improved survival. With intensity-modulated radiation therapy, isodoses can conform to complex volumes. It is widely used and seems to be indicated in locally advanced stages. Its dosimetric improvements have been demonstrated but outcomes are still heterogeneous. Stereotactic radiotherapy allows treatment of small volumes with many narrow beams. Dedicated devices or appropriate equipment on classical devices are needed. In early stages, its efficacy is comparable to surgery with an acceptable toxicity. Endobronchial brachytherapy could be used for early stages with specific criteria. Hadrontherapy is still experimental regarding lung cancer. Hadrons have physical properties leading to very accurate dose distribution. In the rare published studies, toxicities are roughly lower than others techniques but for early stages its effectiveness is not better than stereotactic radiotherapy. These techniques are optimized by metabolic imaging which precisely defines the target volume and assesses the therapeutic response; image-guided radiation therapy which allows a more accurate patient set up and by respiratory tracking or gating which takes account of tumour respiratory motions.

  3. [New technologies: needs and challenges in radiotherapy in Latin America].

    PubMed

    Castellanos, María Esperanza

    2006-01-01

    The cumulative experience gathered over more than a century of practice of radiotherapy has demonstrated the latter's importance not only for the palliative treatment of a fraction of cancer cases, but mainly for the curative treatment of an even greater proportion of such cases. In light of the changes in technology, the ever-increasing access developing countries to such technology, and its current coverage in Latin America, any efforts in this area should be aimed at improving the quality of the radiotherapy services and centers that are already in place. This involves developing their technological assets to the fullest, expanding their services, and complying with the minimum quality requirements established for second-level facilities. Each center should be equipped to carry out all stages of the radiotherapy process, from simulation through treatment verification and patient follow-up, with a high level of quality (level 2). To achieve this, it should possess the necessary technology and properly-trained staff that are required for the purpose. Collaborative efforts in the Region should also prioritize helping countries implement national treatment standards for all stages of the radiotherapy process and promoting the implementation of validated quality assurance programs.

  4. Technical Advances and Pitfalls in Head and Neck Radiotherapy

    PubMed Central

    Parvathaneni, Upendra; Laramore, George E.; Liao, Jay J.

    2012-01-01

    Intensity Modulated Radiotherapy (IMRT) is the standard of care in the treatment of head and neck squamous cell carcinomas (HNSCC) based on level 1 evidence. Technical advances in radiotherapy have revolutionized the treatment of HNSCC, with the most tangible gain being a reduction in long term morbidity. However, these benefits come with a serious and sobering price. Today, there is a greater chance of missing the target/tumor due to uncertainties in target volume definition by the clinician that is demanded by the highly conformal planning process involved with IMRT. Unless this is urgently addressed, our patients would be better served with the historically practiced non conformal radiotherapy, than IMRT which promises lesser morbidity. Image guided radiotherapy (IGRT) ensures the level of set up accuracy warranted to deliver a highly conformal treatment plan and should be utilized with IMRT, where feasible. Proton therapy has a theoretical physical advantage over photon therapy due to a lack of “exit dose”. However, clinical data supporting the routine use of this technology for HNSCC are currently sparse. The purpose of this article is to review the literature, discuss the salient issues and make recommendations that address the gaps in knowledge. PMID:22701482

  5. [Intraoperative radiotherapy with electrons (IORT). Dosimetry problems, first experience].

    PubMed

    Bianciardi, L; Panichelli, V; Benassi, M; Sulprizio, S; Piermattei, A; Azario, L; Arcovito, G; Valentini, V

    1990-10-01

    In this paper, preliminary results on the IORT dosimetry performed on the two radiotherapy centers, "Regina Elena National Cancer Institute" and "S. Cuore Catholic University", are presented. The absolute dosimetry has been performed with ion chambers (ENEA chamber and Markus flat chamber) using a water phantom. The relative measurements have been performed with solid state diodes and radiographic films, calibrated on absolute dosimetry system.

  6. Bayesian network models for error detection in radiotherapy plans

    NASA Astrophysics Data System (ADS)

    Kalet, Alan M.; Gennari, John H.; Ford, Eric C.; Phillips, Mark H.

    2015-04-01

    The purpose of this study is to design and develop a probabilistic network for detecting errors in radiotherapy plans for use at the time of initial plan verification. Our group has initiated a multi-pronged approach to reduce these errors. We report on our development of Bayesian models of radiotherapy plans. Bayesian networks consist of joint probability distributions that define the probability of one event, given some set of other known information. Using the networks, we find the probability of obtaining certain radiotherapy parameters, given a set of initial clinical information. A low probability in a propagated network then corresponds to potential errors to be flagged for investigation. To build our networks we first interviewed medical physicists and other domain experts to identify the relevant radiotherapy concepts and their associated interdependencies and to construct a network topology. Next, to populate the network’s conditional probability tables, we used the Hugin Expert software to learn parameter distributions from a subset of de-identified data derived from a radiation oncology based clinical information database system. These data represent 4990 unique prescription cases over a 5 year period. Under test case scenarios with approximately 1.5% introduced error rates, network performance produced areas under the ROC curve of 0.88, 0.98, and 0.89 for the lung, brain and female breast cancer error detection networks, respectively. Comparison of the brain network to human experts performance (AUC of 0.90 ± 0.01) shows the Bayes network model performs better than domain experts under the same test conditions. Our results demonstrate the feasibility and effectiveness of comprehensive probabilistic models as part of decision support systems for improved detection of errors in initial radiotherapy plan verification procedures.

  7. Clinical radiotherapy audits in Belgium, 2011-2014.

    PubMed

    Scalliet, P G M

    2015-10-01

    Systematic clinical radiotherapy audits have been introduced in Belgium in 2011, as part of the Federal Cancer Plan. This is in compliance with article 11 of the 97/43 Council directive of Euratom states, translated into the Belgian legislation by royal decree in 2002. The principle of clinical audits has thus been part of the federal legal requirements for more than 10 years. However, its application had to wait for the development of a practical approach: what authority will audit, who will be the auditors, along which methodology, at what frequency, etc. Since 2002, the Federal College of Radiotherapy has the mission to monitor quality of radiotherapy at large. It was therefore decided after discussions with the relevant administration at the Ministry of Health and the Federal Agency for Nuclear Control that the College would practically organise the audits. Early in the 2000s, the IAEA developed a manual for comprehensive audits, as a tool for quality improvement. Auditors were professionals of the domain and the audit visit took the form of a peer review. Great care was taken to assemble an audit party able to cover all aspects of clinical radiotherapy with a radiation oncologist, a medical physicist, a radiation therapist and, on demand, a quality officer. The IAEA manual contains a series of questionnaires to be prepared by the audited centre in advance (pre-audit and self-assessment), indicating what specific areas the auditors would assess. It is also a template for the auditors, ensuring that no area is left aside or forgotten during the site visit. The report, at the end of the visit, is drafted according to a specific report template, also developed by IAEA. Several members of the Belgian radiotherapy community have developed their auditor's skills by participating to the IAEA audit program; they are the core of the auditor Belgian team.

  8. Clinical radiotherapy audits in Belgium, 2011-2014.

    PubMed

    Scalliet, P G M

    2015-10-01

    Systematic clinical radiotherapy audits have been introduced in Belgium in 2011, as part of the Federal Cancer Plan. This is in compliance with article 11 of the 97/43 Council directive of Euratom states, translated into the Belgian legislation by royal decree in 2002. The principle of clinical audits has thus been part of the federal legal requirements for more than 10 years. However, its application had to wait for the development of a practical approach: what authority will audit, who will be the auditors, along which methodology, at what frequency, etc. Since 2002, the Federal College of Radiotherapy has the mission to monitor quality of radiotherapy at large. It was therefore decided after discussions with the relevant administration at the Ministry of Health and the Federal Agency for Nuclear Control that the College would practically organise the audits. Early in the 2000s, the IAEA developed a manual for comprehensive audits, as a tool for quality improvement. Auditors were professionals of the domain and the audit visit took the form of a peer review. Great care was taken to assemble an audit party able to cover all aspects of clinical radiotherapy with a radiation oncologist, a medical physicist, a radiation therapist and, on demand, a quality officer. The IAEA manual contains a series of questionnaires to be prepared by the audited centre in advance (pre-audit and self-assessment), indicating what specific areas the auditors would assess. It is also a template for the auditors, ensuring that no area is left aside or forgotten during the site visit. The report, at the end of the visit, is drafted according to a specific report template, also developed by IAEA. Several members of the Belgian radiotherapy community have developed their auditor's skills by participating to the IAEA audit program; they are the core of the auditor Belgian team. PMID:26321683

  9. Recommendations for safer radiotherapy: what’s the message?

    PubMed Central

    Dunscombe, Peter

    2012-01-01

    Radiotherapy, with close to a million courses delivered per year in North America, is a very safe and effective intervention for a devastating disease. However, although rare, several deeply regrettable incidents have occurred in radiotherapy and have rightly been the subject of considerable public interest. Partly in response to reports of these incidents a variety of authoritative organizations across the globe has harnessed the expertise amongst their members in attempts to identify the measures that will make radiotherapy safer. While the intentions of all these organizations are clearly good it is challenging for the health care providers in the clinic to know where to start with so much advice coming from so many directions. Through a mapping exercise we have identified commonalities between recommendations made in seven authoritative documents and identified those issues most frequently cited. The documents reviewed contain a total of 117 recommendations. Using the 37 recommendations in “Towards Safer Radiotherapy” as the initial base layer, recommendations in the other documents were mapped, adding to the base layer to accommodate all the recommendations from the additional six documents as necessary. This mapping exercise resulted in the distillation of the original 117 recommendations down to 61 unique recommendations. Twelve topics were identified in three or more of the documents as being pertinent to the improvement of patient safety in radiotherapy. They are, in order of most to least cited: training, staffing, documentation, incident learning, communication, check lists, quality control and preventive maintenance, dosimetric audit, accreditation, minimizing interruptions, prospective risk assessment, and safety culture. This analysis provides guidance for the selection of those activities most likely to enhance safety and quality in radiotherapy based on the frequency of citation in selected recent authoritative literature. PMID:23061045

  10. Optimum dose of radiotherapy for chemodectomas of the middle ear

    SciTech Connect

    Kim, J.A.; Elkon, D.; Lim, M.L.; Constable, W.C.

    1980-07-01

    Forty patients with chemodectomas of the middle ear were seen at the University of Virginia Hospital from 1932 to 1978. Surgery, post-operative radiotherapy or radiotherapy alone were the treatment modalities employed depending on the extent of the disease. These have been reviewed with regard to the clinical presentation and results of treatment with long term follow-up of 1 to 30 years. An attempt was made to determine the optimum dose of radiotherapy based on our data and reported cases in the literature. The majority of patients complaining of tinnitus, otalgia and pulsation obtained significant if not complete relief of symptoms. Cranial nerve defects, however, ofter persisted after therapy. Tumor was considered to be controlled if there was no increase in its size or progression of symptoms. Tumor control was obtained in eight of 10 early patients but only in two of seven more patients with advanced disease with total resection. Control rate with post-operative radiotherapy after subtotal resection was 85%. Radiotherapy alone was used for inoperable or recurrent tumors and control was obtained in 88% of them. In addition to our data, the radiation dose used in over 200 patients reported in the literature was analyzed. There was only a 2% recurrence rate in patients who received 4000 rad/4 weeks or higher. Twenty-two percent of patients treated with less than 4000 rad developed recurrence. The tendency is to use a lower dose of postoperative treatment and a higher dose for gross inoperable tumors. 4000 rad/4 weeks seems to be adequate for control of postoperative residual disease and no more than 5000 rad/5 weeks are required even for advanced inoperable cases. By keeping the dose below 5000 rad/5 weeks, the incidence of complications such as brain necrosis is greatly decreased.

  11. Proton Radiotherapy for Parameningeal Rhabdomyosarcoma: Clinical Outcomes and Late Effects

    SciTech Connect

    Childs, Stephanie K.; Kozak, Kevin R.; Friedmann, Alison M.; Yeap, Beow Y.; Adams, Judith; MacDonald, Shannon M.; Liebsch, Norbert J.; Tarbell, Nancy J.; Yock, Torunn I.

    2012-02-01

    Purpose: To report the clinical outcome and late side effect profile of proton radiotherapy in the treatment of children with parameningeal rhabdomyosarcoma (PM-RMS). Methods and Materials: Seventeen consecutive children with PM-RMS were treated with proton radiotherapy at Massachusetts General Hospital between 1996 and 2005. We reviewed the medical records of all patients and asked referring physicians to report specific side effects of interest. Results: Median patient age at diagnosis was 3.4 years (range, 0.4-17.6). Embryonal (n = 11), alveolar (n = 4), and undifferentiated (n = 2) histologies were represented. Ten patients (59%) had intracranial extension. Median prescribed dose was 50.4 cobalt gray equivalents (GyRBE) (range, 50.4-56.0 GyRBE) delivered in 1.8-2.0-GyRBE daily fractions. Median follow-up was 5.0 years for survivors. The 5-year failure-free survival estimate was 59% (95% confidence interval, 33-79%), and overall survival estimate was 64% (95% confidence interval, 37-82%). Among the 7 patients who failed, sites of first recurrence were local only (n = 2), regional only (n = 2), distant only (n = 2), and local and distant (n = 1). Late effects related to proton radiotherapy in the 10 recurrence-free patients (median follow-up, 5 years) include failure to maintain height velocity (n = 3), endocrinopathies (n = 2), mild facial hypoplasia (n = 7), failure of permanent tooth eruption (n = 3), dental caries (n = 5), and chronic nasal/sinus congestion (n = 2). Conclusions: Proton radiotherapy for patients with PM-RMS yields tumor control and survival comparable to that in historical controls with similar poor prognostic factors. Furthermore, rates of late effects from proton radiotherapy compare favorably to published reports of photon-treated cohorts.

  12. Radiotherapy and "new" drugs-new side effects?

    PubMed Central

    2011-01-01

    Background and purpose Targeted drugs have augmented the cancer treatment armamentarium. Based on the molecular specificity, it was initially believed that these drugs had significantly less side effects. However, currently it is accepted that all of these agents have their specific side effects. Based on the given multimodal approach, special emphasis has to be placed on putative interactions of conventional cytostatic drugs, targeted agents and other modalities. The interaction of targeted drugs with radiation harbours special risks, since the awareness for interactions and even synergistic toxicities is lacking. At present, only limited is data available regarding combinations of targeted drugs and radiotherapy. This review gives an overview on the current knowledge on such combined treatments. Materials and methods Using the following MESH headings and combinations of these terms pubmed database was searched: Radiotherapy AND cetuximab/trastuzumab/panitumumab/nimotuzumab, bevacizumab, sunitinib/sorafenib/lapatinib/gefitinib/erlotinib/sirolimus, thalidomide/lenalidomide as well as erythropoietin. For citation crosscheck the ISI web of science database was used employing the same search terms. Results Several classes of targeted substances may be distinguished: Small molecules including kinase inhibitors and specific inhibitors, antibodies, and anti-angiogenic agents. Combination of these agents with radiotherapy may lead to specific toxicities or negatively influence the efficacy of RT. Though there is only little information on the interaction of molecular targeted radiation and radiotherapy in clinical settings, several critical incidents are reported. Conclusions The addition of molecular targeted drugs to conventional radiotherapy outside of approved regimens or clinical trials warrants a careful consideration especially when used in conjunction in hypo-fractionated regimens. Clinical trials are urgently needed in order to address the open question in regard

  13. Clinical Experience With Image-Guided Radiotherapy in an Accelerated Partial Breast Intensity-Modulated Radiotherapy Protocol

    SciTech Connect

    Leonard, Charles E.; Tallhamer, Michael M.S.; Johnson, Tim; Hunter, Kari C.M.D.; Howell, Kathryn; Kercher, Jane; Widener, Jodi; Kaske, Terese; Paul, Devchand; Sedlacek, Scot; Carter, Dennis L.

    2010-02-01

    Purpose: To explore the feasibility of fiducial markers for the use of image-guided radiotherapy (IGRT) in an accelerated partial breast intensity modulated radiotherapy protocol. Methods and Materials: Nineteen patients consented to an institutional review board approved protocol of accelerated partial breast intensity-modulated radiotherapy with fiducial marker placement and treatment with IGRT. Patients (1 patient with bilateral breast cancer; 20 total breasts) underwent ultrasound guided implantation of three 1.2- x 3-mm gold markers placed around the surgical cavity. For each patient, table shifts (inferior/superior, right/left lateral, and anterior/posterior) and minimum, maximum, mean error with standard deviation were recorded for each of the 10 BID treatments. The dose contribution of daily orthogonal films was also examined. Results: All IGRT patients underwent successful marker placement. In all, 200 IGRT treatment sessions were performed. The average vector displacement was 4 mm (range, 2-7 mm). The average superior/inferior shift was 2 mm (range, 0-5 mm), the average lateral shift was 2 mm (range, 1-4 mm), and the average anterior/posterior shift was 3 mm (range, 1 5 mm). Conclusions: This study shows that the use of IGRT can be successfully used in an accelerated partial breast intensity-modulated radiotherapy protocol. The authors believe that this technique has increased daily treatment accuracy and permitted reduction in the margin added to the clinical target volume to form the planning target volume.

  14. SU-E-J-206: Adaptive Radiotherapy for Gynecological Malignancies with MRIGuided Cobolt-60 Radiotherapy

    SciTech Connect

    Lamb, J; Kamrava, M; Agazaryan, N; Cao, M; Low, D; Thomas, D; Yang, Y

    2015-06-15

    Purpose: Even in the IMRT era, bowel toxicity and bone marrow irradiation remain concerns with pelvic irradiation. We examine the potential gain from an adaptive radiotherapy workflow for post-operative gynecological patients treated to pelvic targets including lymph nodes using MRI-guided Co-60 radiation therapy. Methods: An adaptive workflow was developed with the intent of minimizing time overhead of adaptive planning. A pilot study was performed using retrospectively analyzed images from one patient’s treatment. The patient’s treated plan was created using conventional PTV margins. Adaptive treatment was simulated on the patient’s first three fractions. The daily PTV was created by removing non-target tissue, including bone, muscle and bowel, from the initial PTV based on the daily MRI. The number of beams, beam angles, and optimization parameters were kept constant, and the plan was re-optimized. Normal tissue contours were not adjusted for the re-optimization, but were adjusted for evaluation of plan quality. Plan quality was evaluated based on PTV coverage and normal tissue DVH points per treatment protocol. Bowel was contoured as the entire bowel bag per protocol at our institution. Pelvic bone marrow was contoured per RTOG protocol 1203. Results: For the clinically treated plan, the volume of bowel receiving 45 Gy was 380 cc, 53% of the rectum received 30 Gy, 35% of the bladder received 45 Gy, and 28% of the pelvic bone marrow received 40 Gy. For the adaptive plans, the volume of bowel receiving 45 Gy was 175–201 cc, 55–62% of the rectum received 30 Gy, 21– 27% of the bladder received 45 Gy, and 13–17% of the pelvic bone marrow received 40 Gy. Conclusion: Adaptive planning led to a large reduction of bowel and bone marrow dose in this pilot study. Further study of on-line adaptive techniques for the radiotherapy of pelvic lymph nodes is warranted. Dr. Low is a member of the scientific advisory board of ViewRay, Inc.

  15. Fractionated Stereotactic Radiotherapy as Reirradiation for Locally Recurrent Head and Neck Cancer

    SciTech Connect

    Roh, Kwang-Won; Jang, Ji-Sun; Kim, Min-Sik; Sun, Dong-Il; Kim, Bum-Soo; Jung, So-Lyoung; Kang, Jin-Hyoung; Yoo, Eun-Jung; Yoon, Sei-Chul; Jang, Hong-Seok; Chung, Su-Mi; Kim, Yeon-Sil

    2009-08-01

    Purpose: We report early preliminary experience with CyberKnife radiosurgery (RS) as salvage treatment for locally recurrent head and neck cancer (HNC). Methods and Materials: Between March 2004 and August 2006, 36 patients (44 sites) were treated with CyberKnife RS as reirradiation for locally recurrent HNC. Treatment sites were as follows: nasopharynx (8), maxillary sinus (8), neck lymph nodes (8), skull base (7), nasal cavity (4), retropharyngeal lymph nodes (3), orbit (2), and others (4). Total doses administered were 18-40 Gy (median, 30 Gy) in 3 to 5 fractions to the 65%-85% isodose line for 3-5 consecutive days. Previous external radiation dose ranged from 39.6 to 134.4 Gy (median, 70.2 Gy). Gross tumor volume ranged from 0.2 to 114.9 cm{sup 3} (median, 22.6 cm{sup 3}). Median follow-up was 17.3 months. Results: Thirty-five of 44 sites were evaluated for response. Fifteen (42.9%) sites achieved complete response, 13 sites (37.1%) achieved a partial response, 3 (8.6%) sites maintained stable disease, and 4 sites (11.4%) showed tumor progression. Grade III acute complications were noted in 13 patients. Late complications were observed in three patients (1 bone necrosis, 2 soft tissue necrosis) during follow-up. Conclusion: These preliminary results suggest that fractionated stereotactic radiosurgery is an effective treatment modality as a salvage treatment with good short-term local control. The early overall response rate is encouraging. However, more experience and a longer follow-up are necessary to determine the role of fractionated stereotactic radiosurgery as a salvage treatment of locally recurrent HNC and to define long-term complications.

  16. Daily Megavoltage Computed Tomography in Lung Cancer Radiotherapy: Correlation Between Volumetric Changes and Local Outcome

    SciTech Connect

    Bral, Samuel; De Ridder, Mark; Duchateau, Michael; Gevaert, Thierry; Engels, Benedikt; Schallier, Denis; Storme, Guy

    2011-08-01

    Purpose: To assess the predictive or comparative value of volumetric changes, measured on daily megavoltage computed tomography during radiotherapy for lung cancer. Patients and Methods: We included 80 patients with locally advanced non-small-cell lung cancer treated with image-guided intensity-modulated radiotherapy. The radiotherapy was combined with concurrent chemotherapy, combined with induction chemotherapy, or given as primary treatment. Patients entered two parallel studies with moderately hypofractionated radiotherapy. Tumor volume contouring was done on the daily acquired images. A regression coefficient was derived from the volumetric changes on megavoltage computed tomography, and its predictive value was validated. Logarithmic or polynomial fits were applied to the intratreatment changes to compare the different treatment schedules radiobiologically. Results: Regardless of the treatment type, a high regression coefficient during radiotherapy predicted for a significantly prolonged cause-specific local progression free-survival (p = 0.05). Significant differences were found in the response during radiotherapy. The significant difference in volumetric treatment response between radiotherapy with concurrent chemotherapy and radiotherapy plus induction chemotherapy translated to a superior long-term local progression-free survival for concurrent chemotherapy (p = 0.03). An enhancement ratio of 1.3 was measured for the used platinum/taxane doublet in comparison with radiotherapy alone. Conclusion: Contouring on daily megavoltage computed tomography images during radiotherapy enabled us to predict the efficacy of a given treatment. The significant differences in volumetric response between treatment strategies makes it a possible tool for future schedule comparison.

  17. International patterns of radiotherapy practice for non-small cell lung cancer.

    PubMed

    Vinod, Shalini K

    2015-04-01

    Radiotherapy is an important treatment modality for non-small cell lung cancer (NSCLC). There are models of radiotherapy utilization that estimate the proportion of patients with NSCLC who have an evidence-based indication for radiotherapy. These estimates range from 46%-68% for radiotherapy utilization at diagnosis and 64%-75% overall. However, actual radiotherapy utilization throughout much of the world is lower than this, ranging from 28%-53%, with the largest differences between actual and estimated radiotherapy utilization seen in stage III NSCLC. Some of this discrepancy is attributable to the assumptions in the models that are based on broad factors such as stage and performance status. Characteristics of the population with underlying lung cancer that often has comorbidities or compromised respiratory function also influence the ability to deliver radiotherapy safely. Sociodemographic factors such as race and income have been found to affect access to radiotherapy in certain jurisdictions. The type of clinician or medical setting the patient presents to initially can also influence radiotherapy use in NSCLC. Potential solutions to improve appropriate radiotherapy utilization for NSCLC include restructuring models of care to ensure that all patients with lung cancer are managed within a multidisciplinary team including a radiation oncologist.

  18. Head & Neck Squamous Cell Carcinoma of Unknown Primary: Neck Dissection and Radiotherapy or Definitive Radiotherapy

    PubMed Central

    Koukourakis, Georgios V.; Gutfeld, Orit; Prince, Mark E.; Bradford, Carol R.; Wolf, Gregory T.; McLean, Scott; Worden, Francis P.; Chepeha, Douglas B.; Schipper, Matthew J.; McHugh, Jonathan B.

    2014-01-01

    Background Management of head and neck carcinoma from unknown primary (HNCUP) remains controversial, with neck dissection and radiotherapy (ND+RT) or definitive RT both commonly used. We aimed to characterize HNCUP and retrospectively compare outcomes for patients treated with ND+RT versus definitive RT. Methods From 1994-2009, 41 HNCUP patients underwent either ND+RT (n=22) or definitive RT+ concurrent chemotherapy (n=19) at our institution. Treatment outcomes were compared using Kaplan-Meier methods and log-rank test. Results There were no differences between patients treated with ND+RT and definitive RT in overall survival (OS), progression-free survival (PFS), or locoregional-relapse-free survival, freedom-from-locoregional failure, or freedom-from-distant failure. Among 17 ND+RT patients for whom human papillomavirus (HPV) status could be determined, HPV(+) patients trended towards improved OS (p=0.06)and PFS (p=0.15). Conclusions Neck dissection and post-op RT resulted in similar outcome as definitive RT. The prognostic implications of HPV(+) nodes in HNCUP are similar to those in oropharyngeal primary cancers. PMID:23996575

  19. Complement is a central mediator of radiotherapy-induced tumor-specific immunity and clinical response.

    PubMed

    Surace, Laura; Lysenko, Veronika; Fontana, Andrea Orlando; Cecconi, Virginia; Janssen, Hans; Bicvic, Antonela; Okoniewski, Michal; Pruschy, Martin; Dummer, Reinhard; Neefjes, Jacques; Knuth, Alexander; Gupta, Anurag; van den Broek, Maries

    2015-04-21

    Radiotherapy induces DNA damage and cell death, but recent data suggest that concomitant immune stimulation is an integral part of the therapeutic action of ionizing radiation. It is poorly understood how radiotherapy supports tumor-specific immunity. Here we report that radiotherapy induced tumor cell death and transiently activated complement both in murine and human tumors. The local production of pro-inflammatory anaphylatoxins C3a and C5a was crucial to the tumor response to radiotherapy and concomitant stimulation of tumor-specific immunity. Dexamethasone, a drug frequently given during radiotherapy, limited complement activation and the anti-tumor effects of the immune system. Overall, our findings indicate that anaphylatoxins are key players in radiotherapy-induced tumor-specific immunity and the ensuing clinical responses.

  20. Past, present, and future of radiotherapy for the benefit of patients.

    PubMed

    Thariat, Juliette; Hannoun-Levi, Jean-Michel; Sun Myint, Arthur; Vuong, Te; Gérard, Jean-Pierre

    2013-01-01

    Radiotherapy has been driven by constant technological advances since the discovery of X-rays in 1895. Radiotherapy aims to sculpt the optimal isodose on the tumour volume while sparing normal tissues. The benefits are threefold: patient cure, organ preservation and cost-efficiency. The efficacy and tolerance of radiotherapy were demonstrated by randomized trials in many different types of cancer (including breast, prostate and rectum) with a high level of scientific evidence. Such achievements, of major importance for the quality of life of patients, have been fostered during the past decade by linear accelerators with computer-assisted technology. More recently, these developments were augmented by proton and particle beam radiotherapy, usually combined with surgery and medical treatment in a multidisciplinary and personalized strategy against cancer. This article reviews the timeline of 100 years of radiotherapy with a focus on breakthroughs in the physics of radiotherapy and technology during the past two decades, and the associated clinical benefits.

  1. [Current Status and Prospects on PET Radiopharmaceuticals for Radiotherapy].

    PubMed

    Yoshimoto, Mitsuyoshi

    2015-01-01

    18F-FDG is a most popular radiopharmaceutical for tumor diagnosis in the world. In addition, 11C-methionine, 18F-FLT and 11C-choline have been used to compensate for drawbacks of 18F-FDG. Now, novel radiopharmaceuticals are required to estimate or predict therapeutic efficacy because we have many strategies to treat tumors. Radiotherapy which damage DNA by producing free radicals is commonly used to treat various types of tumors. Hypoxia is closely associated with resistance to chemo- and/or radiotherapy and is a common feature of solid tumors. Recently, understanding of tumor hypoxia in oncology has led to development of radiopharmaceuticals for hypoxia imaging. This review provides an overview of PET radiopharmaceuticals for hypoxia imaging and 18F-FBPA which is used for boron neutron capture therapy.

  2. Radiotherapy Dose-Volume Effects on Salivary Gland Function

    SciTech Connect

    Deasy, Joseph O.; Moiseenko, Vitali; Marks, Lawrence; Chao, K.S. Clifford; Nam, Jiho; Eisbruch, Avraham

    2010-03-01

    Publications relating parotid dose-volume characteristics to radiotherapy-induced salivary toxicity were reviewed. Late salivary dysfunction has been correlated to the mean parotid gland dose, with recovery occurring with time. Severe xerostomia (defined as long-term salivary function of <25% of baseline) is usually avoided if at least one parotid gland is spared to a mean dose of less than {approx}20 Gy or if both glands are spared to less than {approx}25 Gy (mean dose). For complex, partial-volume RT patterns (e.g., intensity-modulated radiotherapy), each parotid mean dose should be kept as low as possible, consistent with the desired clinical target volume coverage. A lower parotid mean dose usually results in better function. Submandibular gland sparing also significantly decreases the risk of xerostomia. The currently available predictive models are imprecise, and additional study is required to identify more accurate models of xerostomia risk.

  3. Stereotactic body radiotherapy: current strategies and future development

    PubMed Central

    2016-01-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon. PMID:27606082

  4. Stereotactic body radiotherapy: current strategies and future development

    PubMed Central

    2016-01-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon.

  5. Stereotactic body radiotherapy: current strategies and future development.

    PubMed

    Tsang, Maverick W K

    2016-07-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon. PMID:27606082

  6. Newer positron emission tomography radiopharmaceuticals for radiotherapy planning: an overview

    PubMed Central

    Mukherjee, Anirban

    2016-01-01

    Positron emission tomography-computed tomography (PET-CT) has changed cancer imaging in the last decade, for better. It can be employed for radiation treatment planning of different cancers with improved accuracy and outcomes as compared to conventional imaging methods. 18F-fluorodeoxyglucose remains the most widely used though relatively non-specific cancer imaging PET tracer. A wide array of newer PET radiopharmaceuticals has been developed for targeted imaging of different cancers. PET-CT with such new PET radiopharmaceuticals has also been used for radiotherapy planning with encouraging results. In the present review we have briefly outlined the role of PET-CT with newer radiopharmaceuticals for radiotherapy planning and briefly reviewed the available literature in this regard. PMID:26904575

  7. Methods and computer readable medium for improved radiotherapy dosimetry planning

    DOEpatents

    Wessol, Daniel E.; Frandsen, Michael W.; Wheeler, Floyd J.; Nigg, David W.

    2005-11-15

    Methods and computer readable media are disclosed for ultimately developing a dosimetry plan for a treatment volume irradiated during radiation therapy with a radiation source concentrated internally within a patient or incident from an external beam. The dosimetry plan is available in near "real-time" because of the novel geometric model construction of the treatment volume which in turn allows for rapid calculations to be performed for simulated movements of particles along particle tracks therethrough. The particles are exemplary representations of alpha, beta or gamma emissions emanating from an internal radiation source during various radiotherapies, such as brachytherapy or targeted radionuclide therapy, or they are exemplary representations of high-energy photons, electrons, protons or other ionizing particles incident on the treatment volume from an external source. In a preferred embodiment, a medical image of a treatment volume irradiated during radiotherapy having a plurality of pixels of information is obtained.

  8. Generalized Morphea following Radiotherapy for an Intracranial Tumor.

    PubMed

    Balegar, Shrenik; Mishra, Dharmendra Kumar; Chatterjee, Sagarika; Kumari, Shweta; Tiwary, Anup Kumar

    2016-01-01

    Morphea is a localized scleroderma variety which can be circumscribed or generalized and is characterized by sclerotic plaques developing on trunk and limbs. Surgery and radiation have been implicated as etiological factors for the development of morphea. Majority of the radiation-induced morphea cases have occurred in patients with breast cancer. The affected areas have been generally restricted to the area of radiation and nearby surrounding area in most of the reported cases. We hereby report a case of a 27-year-old male who developed radiation-induced progressive generalized morphea after getting radiotherapy for an intracranial tumor. His condition improved after dexamethasone-cyclophosphamide pulse therapy. With increased incidence of cancer worldwide and radiotherapy as a modality of treatment, it is imperative to follow the patient and look for the development of morphea which itself is a debilitating disease. PMID:27688464

  9. When can a drug be considered synergic with radiotherapy?

    PubMed

    Gambacorta, M Antonietta; Macchia, Gabriella; Deodato, Francesco; Murino, Paola; Barba, Maria Cristina; Manfrida, Stefania

    2004-01-01

    The combination of radiotherapy with chemotherapy is now considered the standard treatment for a number of tumors. However frequently, within radiotherapy as well as medical oncology, considerable skepticism has been expressed about the real impact of this therapeutic modality, in spite of the improvement in terms of outcome seen in numerous trials concerning head and neck, lung, esophageal cancer and tumors of the anal canal, the uterine cervix and pancreas. Considering the evident clinical advantages achieved in the last 2-3 decades, a close collaboration between basic, preclinical and clinical research is desirable to further optimize the outcomes based on the present radiobiological knowledge. As for the preclinical evaluation different methods should be concomitantly used to analyze the pharmacokinetics and mechanism of action; the method of tumor growth delay should be used especially in neoadjuvant clinical settings; the method of tumor control should be used when chemoradiation is aimed at the local cure of the patient independently of subsequent surgery.

  10. Results of treatment of uterine cervix cancer by radiotherapy.

    PubMed

    Sinistrero, G; Sismondi, P; Zola, P

    1988-12-01

    The results of treatment of uterine cervix cancer by radiotherapy alone in 259 patients in the period January 1973 to December 1984 are reported. They are analyzed according to patients age, stage, tumor volume, extent of parametrial infiltration, hydronephrosis and nodal status. It is shown that age, tumor volume, extent of parametrial invasion and nodal metastases are the main prognostic factors. Analysis of pelvic failures shows that external radiotherapy followed by curietherapy seems to be the best method for patients with T2b and T3b tumors of small volume (less than 60 mm in diameter), particularly when parametrial infiltration is limited. Patients with T2b tumors of large volume (barrel shaped) seem to need a more aggressive approach, and a higher number of complications are therefore expected. Patients with T3b and massive parametrial infiltration, with T4 and nodal metastases need new and different approaches, possibly including adjuvant chemotherapy.

  11. Adjuvant postoperative radiotherapy for gastric carcinoma with poor prognostic signs.

    PubMed

    Slot, A; Meerwaldt, J H; van Putten, W L; Treurniet-Donker, A D

    1989-12-01

    Fifty-seven patients with poor prognostic factors following resection with curative intent for gastric adenocarcinoma (T3 or T4, positive lymph nodes, positive resection line) received adjuvant radiotherapy. A dose of 30.0-50.0 Gy was given in 10-25 fractions in one course or with a split of 2 weeks after 15 fractions. This was combined with 5-fluorouracil (5-FU) (375 mg/m2) given i.v. as a bolus during the first 4 days of radiation (n = 49). The 5-year survival was 26%; this rate is higher than the figures mentioned in the literature after surgery alone. The only way to prove the role of adjuvant radiotherapy for gastric carcinoma is a prospective randomized trial. PMID:2616813

  12. Current Concepts in Osteoradionecrosis after Head and Neck Radiotherapy.

    PubMed

    Dhanda, J; Pasquier, D; Newman, L; Shaw, R

    2016-07-01

    Osteoradionecrosis (ORN) of the jaws is a feared complication of head and neck radiotherapy. ORN causes significant morbidity for patients and controversy among clinicians. This overview considers the variations in definition and classification of the condition that affect estimates of incidence and also the interpretation of evidence. The influence of newer radiotherapy techniques in reducing ORN through reduced dose and xerostomia is balanced against a probable increase in a vulnerable population through a rising head and neck cancer incidence. Theories of pathophysiology of ORN include radiation-induced osteomyelitis, hypoxic and hypovascular theory and fibroatrophic theory. Prevention strategies include restorative dentistry and radiation planning techniques. Treatments range from conservative 'watch and wait' through to more radical surgical strategies. Newer medical management strategies are available with a limited evidence base. The use of hyperbaric oxygen therapy remains controversial and the background and need for newer hyperbaric oxygen trials is discussed. PMID:27038708

  13. Radiotherapy Monte Carlo simulation using cloud computing technology.

    PubMed

    Poole, C M; Cornelius, I; Trapp, J V; Langton, C M

    2012-12-01

    Cloud computing allows for vast computational resources to be leveraged quickly and easily in bursts as and when required. Here we describe a technique that allows for Monte Carlo radiotherapy dose calculations to be performed using GEANT4 and executed in the cloud, with relative simulation cost and completion time evaluated as a function of machine count. As expected, simulation completion time decreases as 1/n for n parallel machines, and relative simulation cost is found to be optimal where n is a factor of the total simulation time in hours. Using the technique, we demonstrate the potential usefulness of cloud computing as a solution for rapid Monte Carlo simulation for radiotherapy dose calculation without the need for dedicated local computer hardware as a proof of principal.

  14. Radiotherapy Dose-Volume Effects on Salivary Gland Function

    PubMed Central

    Deasy, Joseph O.; Moiseenko, Vitali; Marks, Lawrence; Chao, K. S. Clifford; Nam, Jiho; Eilsbruch, Avraham

    2013-01-01

    Publications relating parotid dose-volume characteristics to radiotherapy-induced salivary toxicity were reviewed. Late salivary dysfunction has been correlated to the mean parotid gland dose, with recovery occurring with time. Severe xerostomia (defined as long-term salivary function of <25% of baseline) is usually avoided if at least one parotid gland is spared to a mean dose of less than ≈20 Gy or if both glands are spared to less than ≈25 Gy (mean dose). For complex, partial-volume RT patterns (e.g., intensity-modulated radiotherapy), each parotid mean dose should be kept as low as possible, consistent with the desired clinical target volume coverage. A lower parotid mean dose usually results in better function. Submandibular gland sparing also significantly decreases the risk of xerostomia. The currently available predictive models are imprecise, and additional study is required to identify more accurate models of xerostomia risk. PMID:20171519

  15. Generalized Morphea following Radiotherapy for an Intracranial Tumor

    PubMed Central

    Balegar, Shrenik; Mishra, Dharmendra Kumar; Chatterjee, Sagarika; Kumari, Shweta; Tiwary, Anup Kumar

    2016-01-01

    Morphea is a localized scleroderma variety which can be circumscribed or generalized and is characterized by sclerotic plaques developing on trunk and limbs. Surgery and radiation have been implicated as etiological factors for the development of morphea. Majority of the radiation-induced morphea cases have occurred in patients with breast cancer. The affected areas have been generally restricted to the area of radiation and nearby surrounding area in most of the reported cases. We hereby report a case of a 27-year-old male who developed radiation-induced progressive generalized morphea after getting radiotherapy for an intracranial tumor. His condition improved after dexamethasone-cyclophosphamide pulse therapy. With increased incidence of cancer worldwide and radiotherapy as a modality of treatment, it is imperative to follow the patient and look for the development of morphea which itself is a debilitating disease. PMID:27688464

  16. Adjuvant postoperative radiotherapy for gastric carcinoma with poor prognostic signs.

    PubMed

    Slot, A; Meerwaldt, J H; van Putten, W L; Treurniet-Donker, A D

    1989-12-01

    Fifty-seven patients with poor prognostic factors following resection with curative intent for gastric adenocarcinoma (T3 or T4, positive lymph nodes, positive resection line) received adjuvant radiotherapy. A dose of 30.0-50.0 Gy was given in 10-25 fractions in one course or with a split of 2 weeks after 15 fractions. This was combined with 5-fluorouracil (5-FU) (375 mg/m2) given i.v. as a bolus during the first 4 days of radiation (n = 49). The 5-year survival was 26%; this rate is higher than the figures mentioned in the literature after surgery alone. The only way to prove the role of adjuvant radiotherapy for gastric carcinoma is a prospective randomized trial.

  17. [Current Status and Prospects on PET Radiopharmaceuticals for Radiotherapy].

    PubMed

    Yoshimoto, Mitsuyoshi

    2015-01-01

    18F-FDG is a most popular radiopharmaceutical for tumor diagnosis in the world. In addition, 11C-methionine, 18F-FLT and 11C-choline have been used to compensate for drawbacks of 18F-FDG. Now, novel radiopharmaceuticals are required to estimate or predict therapeutic efficacy because we have many strategies to treat tumors. Radiotherapy which damage DNA by producing free radicals is commonly used to treat various types of tumors. Hypoxia is closely associated with resistance to chemo- and/or radiotherapy and is a common feature of solid tumors. Recently, understanding of tumor hypoxia in oncology has led to development of radiopharmaceuticals for hypoxia imaging. This review provides an overview of PET radiopharmaceuticals for hypoxia imaging and 18F-FBPA which is used for boron neutron capture therapy. PMID:26753391

  18. Generalized Morphea following Radiotherapy for an Intracranial Tumor

    PubMed Central

    Balegar, Shrenik; Mishra, Dharmendra Kumar; Chatterjee, Sagarika; Kumari, Shweta; Tiwary, Anup Kumar

    2016-01-01

    Morphea is a localized scleroderma variety which can be circumscribed or generalized and is characterized by sclerotic plaques developing on trunk and limbs. Surgery and radiation have been implicated as etiological factors for the development of morphea. Majority of the radiation-induced morphea cases have occurred in patients with breast cancer. The affected areas have been generally restricted to the area of radiation and nearby surrounding area in most of the reported cases. We hereby report a case of a 27-year-old male who developed radiation-induced progressive generalized morphea after getting radiotherapy for an intracranial tumor. His condition improved after dexamethasone-cyclophosphamide pulse therapy. With increased incidence of cancer worldwide and radiotherapy as a modality of treatment, it is imperative to follow the patient and look for the development of morphea which itself is a debilitating disease.

  19. Assessing residual motion for gated proton-beam radiotherapy.

    PubMed

    Sharp, Gregory C; Lu, Hsiao Ming; Trofimov, Alexei; Tang, Xiaoli; Jiang, Steve B; Turcotte, Julie; Gierga, David P; Chen, George T Y; Hong, Theodore S

    2007-01-01

    Gated radiation therapy is a promising method for improving the dose conformality of treatments to moving targets and reducing the total volume of irradiated tissue. Target motion is of particular concern in proton beam radiotherapy, due to the finite range of proton dose deposition in tissue. Gating allows one to reduce the extent of variation, due to respiration, of the radiological depth to target during treatment delivery. However, respiratory surrogates typically used for gating do not always accurately reflect the position of the internal target. For instance, a phase delay often exists between the internal motion and the motion of the surrogate. Another phenomenon, baseline drifting refers to a gradual change in the exhale position over time, which generally affects the external and internal markers differently. This study examines the influence of these two physiological phenomena on gated radiotherapy using an external surrogate.

  20. Adenocarcinoma of the ethmoid following radiotherapy for bilateral retinoblastoma

    SciTech Connect

    Rowe, L.D.; Lane, R.; Snow, J.B. Jr.

    1980-01-01

    Adenocarcinoma of the ethmoid sinus is rare, representing only 4 to 8% of malignancies of the paranasal sinuses. An extraordinary case of papillary adenocarcinoma of the ethmoid sinus arising 30 years following high-dose radiotherapy for bilateral retinoblastoma is presented. Histologically, the findings of a papillary pattern of poorly differentiated, mucicarmine-staining cells enclosing gland-like spaces, and the absence of pseudorosettes, melanin, mesenchymal and peripheral neural elements supports an epithelial origin of this tumor. The high incidence of second fatal primary neoplasms in patients with bilateral retinoblastomas receiving radiation suggests an innate susceptibility that may add to the risk of radiotherapy. Careful long-term head and neck surveillance is mandatory if early aggressive management of these extremely lethal tumors is to be successful.

  1. Delivery validation of VMAT stereotactic ablative body radiotherapy at commissioning

    NASA Astrophysics Data System (ADS)

    Olding, T.; Alexander, K. M.; Jechel, C.; Nasr, A. T.; Joshi, C.

    2015-01-01

    Dosimetric validation of two volumetric modulated arc therapy (VMAT) stereotactic ablative radiotherapy (SABR) plans was completed as part of the commissioning process of this technique in our clinic. Static and dynamic ion chamber, EBT3 film and leuco crystal violet (LCV) micelle gel measurements were acquired using a motion phantom with appropriate inserts for each dosimeter. The results show good agreement between measured and calculated plan dose.

  2. Hypofractionation Regimens for Stereotactic Radiotherapy for Large Brain Tumors

    SciTech Connect

    Yuan Jiankui; Wang, Jian Z. Lo, Simon; Grecula, John C.; Ammirati, Mario; Montebello, Joseph F.; Zhang Hualin; Gupta, Nilendu; Yuh, William T.C.; Mayr, Nina A.

    2008-10-01

    Purpose: To investigate equivalent regimens for hypofractionated stereotactic radiotherapy (HSRT) for brain tumor treatment and to provide dose-escalation guidance to maximize the tumor control within the normal brain tolerance. Methods and Materials: The linear-quadratic model, including the effect of nonuniform dose distributions, was used to evaluate the HSRT regimens. The {alpha}/{beta} ratio was estimated using the Gammaknife stereotactic radiosurgery (GKSRS) and whole-brain radiotherapy experience for large brain tumors. The HSRT regimens were derived using two methods: (1) an equivalent tumor control approach, which matches the whole-brain radiotherapy experience for many fractions and merges it with the GKSRS data for few fractions; and (2) a normal-tissue tolerance approach, which takes advantages of the dose conformity and fractionation of HSRT to approach the maximal dose tolerance of the normal brain. Results: A plausible {alpha}/{beta} ratio of 12 Gy for brain tumor and a volume parameter n of 0.23 for normal brain were derived from the GKSRS and whole-brain radiotherapy data. The HSRT prescription regimens for the isoeffect of tumor irradiation were calculated. The normal-brain equivalent uniform dose decreased as the number of fractions increased, because of the advantage of fractionation. The regimens for potential dose escalation of HSRT within the limits of normal-brain tolerance were derived. Conclusions: The designed hypofractionated regimens could be used as a preliminary guide for HSRT dose prescription for large brain tumors to mimic the GKSRS experience and for dose escalation trials. Clinical studies are necessary to further tune the model parameters and validate these regimens.

  3. [External contour acquisition system for radiotherapy: an original solution].

    PubMed

    Létourneau, D; Brochet, F; Bohémier, R; Gagnon, J

    2000-01-01

    A contour acquisition system has been designed in radiotherapy at the Sagamie Hospital complex (Chicoutimi, Québec) to measure the external contours of the patients who do not need a CT exam. This measuring system can produce transversal, sagittal or coronal patient contours in the treatment position. The absolute accuracy of the system is +/- 1 mm. The contours produced by this equipment can be transferred electronically or on paper to the planning system.

  4. [Radiotherapy for localized gastric and orbital MALT lymphomas].

    PubMed

    Quéro, L; Hennequin, C; Amorim, S; Guillerm, S; Ruskoné-Fourmestraux, A; Thieblemont, C

    2016-10-01

    Primary gastric and orbital MALT lymphomas are both low grade (indolent) B-cell non-Hodgkin's lymphomas. Traditionally, these tumors are radiosensitive and have a good prognosis. In localized orbital and stages IE-IIE gastric MALT lymphomas without Helicobacter pylori infection or in case of persistent H. pylori infection after eradication therapy, several retrospective studies have shown that radiotherapy was an effective and well-tolerated treatment. PMID:27614509

  5. The Efficacy of Radiotherapy in the Treatment of Orbital Pseudotumor

    SciTech Connect

    Matthiesen, Chance; Bogardus, Carl; Thompson, J. Spencer; Farris, Bradley; Hildebrand, Lloyd; Wilkes, Byron; Syzek, Elizabeth; Algan, Ozer; Ahmad, Salahuddin; Herman, Terence

    2011-04-01

    Purpose: To review institutional outcomes for patients treated with external-beam radiotherapy (EBRT) for orbital pseudotumor. Methods and Materials: This is a single-institution retrospective review of 20 orbits in 16 patients diagnosed with orbital pseudotumor that received EBRT at the University of Oklahoma, Department of Radiation Oncology. Treated patients had a median follow-up of 16.5 months. Results: Fifteen patients (93.7%) were initially treated with corticosteroids. Eight had recurrence after steroid cessation, six were unable to taper corticosteroids completely or partially, and one experienced progression of symptoms despite corticosteroid therapy. Fourteen patients (87.5%) initially responded to radiotherapy indicated by clinical improvement of preradiation symptoms and/or tapering of corticosteroid dose. Mean EBRT dose was 20 Gy (range, 14-30 Gy). Thirteen patients (81.2%) continued to improve after radiation therapy. Patient outcomes were complete cessation of corticosteroid therapy in nine patients (56.3%) and reduced corticosteroid dose in four patients (25%). Radiotherapy did not achieve long-term control for three patients (18.7%), who still required preradiation corticosteroid dosages. Three patients received retreatment(s) of four orbits, of which two patients achieved long-term symptom control without corticosteroid dependence. One patient received retreatment to an orbit three times, achieving long-term control without corticosteroid dependence. No significant late effects have been observed in retreated patients. Conclusions: Radiotherapy is an effective treatment for acute symptomatic improvement and long-term control of orbital pseudotumor. Orbital retreatment can be of clinical benefit, without apparent increase in morbidity, when initial irradiation fails to achieve complete response.

  6. The Emerging Role of Carbon-Ion Radiotherapy

    PubMed Central

    Ebner, Daniel K.; Kamada, Tadashi

    2016-01-01

    Carbon-ion radiotherapy (CIRT) has progressed rapidly in technological delivery, indications, and efficacy. Owing to a focused dose distribution in addition to high linear energy transfer and subsequently high relative biological effect, CIRT is uniquely able to target otherwise untreatable hypoxic and radioresistant disease while opening the door for substantially hypofractionated treatment of normal and radiosensitive disease. CIRT has increasingly garnered international attention and is nearing the tipping point for international adoption. PMID:27376030

  7. The Emerging Role of Carbon-Ion Radiotherapy.

    PubMed

    Ebner, Daniel K; Kamada, Tadashi

    2016-01-01

    Carbon-ion radiotherapy (CIRT) has progressed rapidly in technological delivery, indications, and efficacy. Owing to a focused dose distribution in addition to high linear energy transfer and subsequently high relative biological effect, CIRT is uniquely able to target otherwise untreatable hypoxic and radioresistant disease while opening the door for substantially hypofractionated treatment of normal and radiosensitive disease. CIRT has increasingly garnered international attention and is nearing the tipping point for international adoption. PMID:27376030

  8. Human mesenchymal stem cells enhance the systemic effects of radiotherapy.

    PubMed

    de Araújo Farias, Virgínea; O'Valle, Francisco; Lerma, Borja Alonso; Ruiz de Almodóvar, Carmen; López-Peñalver, Jesús J; Nieto, Ana; Santos, Ana; Fernández, Beatriz Irene; Guerra-Librero, Ana; Ruiz-Ruiz, María Carmen; Guirado, Damián; Schmidt, Thomas; Oliver, Francisco Javier; Ruiz de Almodóvar, José Mariano

    2015-10-13

    The outcome of radiotherapy treatment might be further improved by a better understanding of individual variations in tumor radiosensitivity and normal tissue reactions, including the bystander effect. For many tumors, however, a definitive cure cannot be achieved, despite the availablity of more and more effective cancer treatments. Therefore, any improvement in the efficacy of radiotherapy will undoubtedly benefit a significant number of patients. Many experimental studies measure a bystander component of tumor cell death after radiotherapy, which highlights the importance of confirming these observations in a preclinical situation. Mesenchymal stem cells (MSCs) have been investigated for use in the treatment of cancers as they are able to both preferentially home onto tumors and become incorporated into their stroma. This process increases after radiation therapy. In our study we show that in vitro MSCs, when activated with a low dose of radiation, are a source of anti-tumor cytokines that decrease the proliferative activity of tumor cells, producing a potent cytotoxic synergistic effect on tumor cells. In vivo administration of unirradiated mesenchymal cells together with radiation leads to an increased efficacy of radiotherapy, thus leading to an enhancement of short and long range bystander effects on primary-irradiated tumors and distant-non-irradiated tumors. Our experiments indicate an increased cell loss rate and the decrease in the tumor cell proliferation activity as the major mechanisms underlying the delayed tumor growth and are a strong indicator of the synergistic effect between RT and MSC when they are applied together for tumor treatment in this model. PMID:26378036

  9. Human mesenchymal stem cells enhance the systemic effects of radiotherapy

    PubMed Central

    de Araújo Farias, Virgínea; O'Valle, Francisco; Lerma, Borja Alonso; Ruiz de Almodóvar, Carmen; López-Peñalver, Jesús J.; Nieto, Ana; Santos, Ana; Fernández, Beatriz Irene; Guerra-Librero, Ana; Ruiz-Ruiz, María Carmen; Guirado, Damián; Schmidt, Thomas; Oliver, Francisco Javier; Ruiz de Almodóvar, José Mariano

    2015-01-01

    The outcome of radiotherapy treatment might be further improved by a better understanding of individual variations in tumor radiosensitivity and normal tissue reactions, including the bystander effect. For many tumors, however, a definitive cure cannot be achieved, despite the availablity of more and more effective cancer treatments. Therefore, any improvement in the efficacy of radiotherapy will undoubtedly benefit a significant number of patients. Many experimental studies measure a bystander component of tumor cell death after radiotherapy, which highlights the importance of confirming these observations in a preclinical situation. Mesenchymal stem cells (MSCs) have been investigated for use in the treatment of cancers as they are able to both preferentially home onto tumors and become incorporated into their stroma. This process increases after radiation therapy. In our study we show that in vitro MSCs, when activated with a low dose of radiation, are a source of anti-tumor cytokines that decrease the proliferative activity of tumor cells, producing a potent cytotoxic synergistic effect on tumor cells. In vivo administration of unirradiated mesenchymal cells together with radiation leads to an increased efficacy of radiotherapy, thus leading to an enhancement of short and long range bystander effects on primary-irradiated tumors and distant-non-irradiated tumors. Our experiments indicate an increased cell loss rate and the decrease in the tumor cell proliferation activity as the major mechanisms underlying the delayed tumor growth and are a strong indicator of the synergistic effect between RT and MSC when they are applied together for tumor treatment in this model. PMID:26378036

  10. Image-guided radiotherapy and motion management in lung cancer

    PubMed Central

    2015-01-01

    In this review, image guidance and motion management in radiotherapy for lung cancer is discussed. Motion characteristics of lung tumours and image guidance techniques to obtain motion information are elaborated. Possibilities for management of image guidance and motion in the various steps of the treatment chain are explained, including imaging techniques and beam delivery techniques. Clinical studies using different motion management techniques are reviewed, and finally future directions for image guidance and motion management are outlined. PMID:25955231

  11. Intensity-modulated radiotherapy in the treatment of gynaecological cancers.

    PubMed

    D'Souza, D P; Rumble, R B; Fyles, A; Yaremko, B; Warde, P

    2012-09-01

    Intensity-modulated radiotherapy (IMRT) is a newer method of radiotherapy that uses intensity-modulated beams that can provide multiple intensity levels for any single beam direction and any single source position allowing concave dose distributions and dose gradients with narrower margins than those possible using conventional methods. IMRT is ideal for treating complex treatment volumes and avoiding close proximity organs at risk that may be dose limiting and provides increased tumour control through an escalated dose and reduces normal tissue complications through organ at risk sparing. Given the potential advantages of IMRT and the availability of IMRT-enabled treatment planning systems and linear accelerators, IMRT has been introduced in a number of disease sites. This systematic review examined the evidence for IMRT in the treatment of gynaecological cancers to quantify the potential benefits of this new technology and to make recommendations for radiation treatment programmes considering adopting this technique. Findings were based on a review of four cohort studies, one of which was prospective, including a total of 619 patients. If reducing acute and chronic toxicity are the main outcomes of interest, then IMRT may be considered over three-dimensional conformal radiotherapy for women with gynaecological cancers; if disease-related outcomes are the main outcomes of interest, there are insufficient data to recommend IMRT over three-dimensional conformal radiotherapy. Future research should focus on prospective multicentre studies reporting on both acute and chronic toxicity as well as survival and recurrence. Dose escalation studies should be carried out to investigate the effect of higher doses on disease.

  12. Monte Carlo verification of gel dosimetry measurements for stereotactic radiotherapy

    NASA Astrophysics Data System (ADS)

    Kairn, T.; Taylor, M. L.; Crowe, S. B.; Dunn, L.; Franich, R. D.; Kenny, J.; Knight, R. T.; Trapp, J. V.

    2012-06-01

    The quality assurance of stereotactic radiotherapy and radiosurgery treatments requires the use of small-field dose measurements that can be experimentally challenging. This study used Monte Carlo simulations to establish that PAGAT dosimetry gel can be used to provide accurate, high-resolution, three-dimensional dose measurements of stereotactic radiotherapy fields. A small cylindrical container (4 cm height, 4.2 cm diameter) was filled with PAGAT gel, placed in the parietal region inside a CIRS head phantom and irradiated with a 12-field stereotactic radiotherapy plan. The resulting three-dimensional dose measurement was read out using an optical CT scanner and compared with the treatment planning prediction of the dose delivered to the gel during the treatment. A BEAMnrc/DOSXYZnrc simulation of this treatment was completed, to provide a standard against which the accuracy of the gel measurement could be gauged. The three-dimensional dose distributions obtained from Monte Carlo and from the gel measurement were found to be in better agreement with each other than with the dose distribution provided by the treatment planning system's pencil beam calculation. Both sets of data showed close agreement with the treatment planning system's dose distribution through the centre of the irradiated volume and substantial disagreement with the treatment planning system at the penumbrae. The Monte Carlo calculations and gel measurements both indicated that the treated volume was up to 3 mm narrower, with steeper penumbrae and more variable out-of-field dose, than predicted by the treatment planning system. The Monte Carlo simulations allowed the accuracy of the PAGAT gel dosimeter to be verified in this case, allowing PAGAT gel to be utilized in the measurement of dose from stereotactic and other radiotherapy treatments, with greater confidence in the future. Experimental aspects of this work were originally presented at the Engineering and Physical Sciences in Medicine

  13. Intensity-modulated radiotherapy in the treatment of prostate cancer.

    PubMed

    Bauman, G; Rumble, R B; Chen, J; Loblaw, A; Warde, P

    2012-09-01

    Three-dimensional conformal radiotherapy (3DCRT) as the primary treatment for prostate cancer has improved outcomes compared with conventional radiotherapy, but with an associated increase in toxicity due to radiation effects on the bladder and rectum. Intensity-modulated radiotherapy (IMRT) is a newer method of radiotherapy that uses intensity-modulated beams that can provide multiple intensity levels for any single beam direction and any single source position allowing concave dose distributions and dose gradients with narrower margins than those possible using conventional methods. IMRT is ideal for treating complex treatment volumes and avoiding close proximity organs at risk that may be dose limiting and provides increased tumour control through an escalated dose and reduces normal tissue complications through organ at risk sparing. Given the potential advantages of IMRT and the availability of IMRT-enabled treatment planning systems and linear accelerators, IMRT has been introduced in a number of disease sites, including prostate cancer. This systematic review examined the evidence for IMRT in the treatment of prostate cancer in order to quantify the potential benefits of this new technology and to make recommendations for radiation treatment programmes considering adopting this technique. The findings were in favour of recommending IMRT over 3DCRT in the radical treatment of localised prostate cancer where doses greater than 70 Gy are required, based on a review of 11 published reports including 4559 patients. There were insufficient data to recommend IMRT over 3DCRT in the postoperative setting. Future research should examine image-guided IMRT in the post-prostatectomy setting, with altered fractionation, and in combination with hormone and chemotherapy.

  14. Merkel Cell Carcinoma: When Does Size Matter for Radiotherapy?

    PubMed Central

    Roach, Michelle; Lee, Mark T

    2015-01-01

    Merkel cell carcinoma is a very aggressive, rare cancer of the skin. It has a high propensity for local, regional, and distant recurrence and has recently been associated with a viral etiology from the recently diagnosed Merkel Cell Polyoma Virus. The optimal management remains controversial. We discuss the case of a man with a 26 cm axillary lymph node metastasis of unknown primary treated with radiotherapy. PMID:26858924

  15. Damped sinusoidal function to model acute irradiation in radiotherapy patients.

    PubMed

    Tukiendorf, Andrzej; Miszczyk, Leszek; Bojarski, Jacek

    2013-09-01

    In the paper, we suggest a damped sinusoidal function be used to model a regenerative response of mucosa in time after the radiotherapy treatment. The medical history of 389 RT patients irradiated within the years 1994-2000 at the Radiotherapy Department, Cancer Center, Maria Skłodowska-Curie Memorial Institute of Oncology, Gliwice, Poland, was taken into account. In the analyzed group of patients, the number of observations of a single patient ranged from 2 to 25 (mean = 8.3, median = 8) with severity determined by use of Dische's scores from 0 to 24 (mean = 7.4, median = 7). Statistical modeling of radiation-induced mucositis was performed for five groups of patients irradiated within the following radiotherapy schedules: CAIR, CB, Manchester, CHA-CHA, and Conventional. All of the regression parameters of the assumed model, i.e. amplitude, damping coefficient, angular frequency, phase of component, and offset, estimated in the analysis were statistically significant (p-value < 0.05) for the radiotherapy schedules. The model was validated using a non-oscillatory function. Following goodness-of-fit statistics, the damped sinusoidal function fits the data better than the non-oscillatory damped function. Model curves for harmonic characteristics with confidence intervals were plotted separately for each of the RT schedules and together in a combined design. The suggested model might be helpful in the numeric evaluation of the RT toxicity in the groups of patients under analysis as it allows for practical comparisons and treatment optimization. A statistical approach is also briefly described in the paper.

  16. Rapid onset of cutaneous angiosarcoma after radiotherapy for breast carcinoma

    SciTech Connect

    Otis, C.N.; Peschel, R.; McKhann, C.; Merino, M.J.; Duray, P.H.

    1986-06-01

    Malignant neoplasms known to develop following external beam radiation include squamous cell carcinoma, osteosarcoma, chondrosarcoma, malignant fibrous histiocytoma, mixed mullerian tumors, malignant schwannoma, myelogenous leukemia and angiosarcoma. Latency periods of many years characterize the onset of these tumors following the exposure. Cutaneous angiosarcoma following radiotherapy for breast carcinoma has been rarely documented, occurring up to 13 years postirradiation. Two cases of this entity are reported occurring 37 months postradiotherapy at the site of mastectomy performed for mammary duct carcinoma.

  17. Multimodality image integration for radiotherapy treatment: an easy approach

    NASA Astrophysics Data System (ADS)

    Santos, Andres; Pascau, Javier; Desco, Manuel; Santos, Juan A.; Calvo, Felipe A.; Benito, Carlos; Garcia-Barreno, Rafael

    2001-05-01

    The interest of using combined MR and CT information for radiotherapy planning is well documented. However, many planning workstations do not allow to use MR images, nor import predefined contours. This paper presents a new simple approach for transferring segmentation results from MRI to a CT image that will be used for radiotherapy planning, using the same original CT format. CT and MRI images of the same anatomical area are registered using mutual information (MI) algorithm. Targets and organs at risk are segmented by the physician on the MR image, where their contours are easy to track. A locally developed software running on PC is used for this step, with several facilities for the segmentation process. The result is transferred onto the CT by slightly modifying up and down the original Hounsfield values of some points of the contour. This is enough to visualize the contour on the CT, but does not affect dose calculations. The CT is then stored using the original file format of the radiotherapy planning workstation, where the technician uses the segmented contour to design the correct beam positioning. The described method has been tested in five patients. Simulations and patient results show that the dose distribution is not affected by the small modification of pixels of the CT image, while the segmented structures can be tracked in the radiotherapy planning workstation-using adequate window/level settings. The presence of the physician is not requires at the planning workstation, and he/she can perform the segmentation process using his/her own PC. This new approach makes it possible to take advantage from the anatomical information present on the MRI and to transfer the segmentation to the CT used for planning, even when the planning workstation does not allow to import external contours. The physician can draw the limits of the target and areas at risk off-line, thus separating in time the segmentation and planning tasks and increasing the efficiency.

  18. A Mathematical Model of Cancer Treatment by Radiotherapy

    PubMed Central

    Yang, Chenxue

    2014-01-01

    A periodic mathematical model of cancer treatment by radiotherapy is presented and studied in this paper. Conditions on the coexistence of the healthy and cancer cells are obtained. Furthermore, sufficient conditions on the existence and globally asymptotic stability of the positive periodic solution, the cancer eradication periodic solution, and the cancer win periodic solution are established. Some numerical examples are shown to verify the validity of the results. A discussion is presented for further study. PMID:25478002

  19. Enhanced relative biological effectiveness of proton radiotherapy in tumor cells with internalized gold nanoparticles

    SciTech Connect

    Polf, Jerimy C.; Gillin, Michael; Bronk, Lawrence F.; Driessen, Wouter H. P.; Arap, Wadih; Pasqualini, Renata

    2011-05-09

    The development and use of sensitizing agents to improve the effectiveness of radiotherapy have long been sought to improve our ability to treat cancer. In this letter, we have studied the relative biological effectiveness of proton beam radiotherapy on prostate tumor cells with and without internalized gold nanoparticles. The effectiveness of proton radiotherapy for the killing of prostate tumor cells was increased by approximately 15%-20% for those cells containing internalized gold nanoparticles.

  20. Translational Research to Improve the Efficacy of Carbon Ion Radiotherapy: Experience of Gunma University

    PubMed Central

    Oike, Takahiro; Sato, Hiro; Noda, Shin-ei; Nakano, Takashi

    2016-01-01

    Carbon ion radiotherapy holds great promise for cancer therapy. Clinical data show that carbon ion radiotherapy is an effective treatment for tumors that are resistant to X-ray radiotherapy. Since 1994 in Japan, the National Institute of Radiological Sciences has been heading the development of carbon ion radiotherapy using the Heavy Ion Medical Accelerator in Chiba. The Gunma University Heavy Ion Medical Center (GHMC) was established in the year 2006 as a proof-of-principle institute for carbon ion radiotherapy with a view to facilitating the worldwide spread of compact accelerator systems. Along with the management of more than 1900 cancer patients to date, GHMC engages in translational research to improve the treatment efficacy of carbon ion radiotherapy. Research aimed at guiding patient selection is of utmost importance for making the most of carbon ion radiotherapy, which is an extremely limited medical resource. Intratumoral oxygen levels, radiation-induced cellular apoptosis, the capacity to repair DNA double-strand breaks, and the mutational status of tumor protein p53 and epidermal growth factor receptor genes are all associated with X-ray sensitivity. Assays for these factors are useful in the identification of X-ray-resistant tumors for which carbon ion radiotherapy would be beneficial. Research aimed at optimizing treatments based on carbon ion radiotherapy is also important. This includes assessment of dose fractionation, normal tissue toxicity, tumor cell motility, and bystander effects. Furthermore, the efficacy of carbon ion radiotherapy will likely be enhanced by research into combined treatment with other modalities such as chemotherapy. Several clinically available chemotherapeutic drugs (carboplatin, paclitaxel, and etoposide) and drugs at the developmental stage (Wee-1 and heat shock protein 90 inhibitors) show a sensitizing effect on tumor cells treated with carbon ions. Additionally, the efficacy of carbon ion radiotherapy can be improved by

  1. Enhanced relative biological effectiveness of proton radiotherapy in tumor cells with internalized gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Polf, Jerimy C.; Bronk, Lawrence F.; Driessen, Wouter H. P.; Arap, Wadih; Pasqualini, Renata; Gillin, Michael

    2011-05-01

    The development and use of sensitizing agents to improve the effectiveness of radiotherapy have long been sought to improve our ability to treat cancer. In this letter, we have studied the relative biological effectiveness of proton beam radiotherapy on prostate tumor cells with and without internalized gold nanoparticles. The effectiveness of proton radiotherapy for the killing of prostate tumor cells was increased by approximately 15%-20% for those cells containing internalized gold nanoparticles.

  2. Translational Research to Improve the Efficacy of Carbon Ion Radiotherapy: Experience of Gunma University.

    PubMed

    Oike, Takahiro; Sato, Hiro; Noda, Shin-Ei; Nakano, Takashi

    2016-01-01

    Carbon ion radiotherapy holds great promise for cancer therapy. Clinical data show that carbon ion radiotherapy is an effective treatment for tumors that are resistant to X-ray radiotherapy. Since 1994 in Japan, the National Institute of Radiological Sciences has been heading the development of carbon ion radiotherapy using the Heavy Ion Medical Accelerator in Chiba. The Gunma University Heavy Ion Medical Center (GHMC) was established in the year 2006 as a proof-of-principle institute for carbon ion radiotherapy with a view to facilitating the worldwide spread of compact accelerator systems. Along with the management of more than 1900 cancer patients to date, GHMC engages in translational research to improve the treatment efficacy of carbon ion radiotherapy. Research aimed at guiding patient selection is of utmost importance for making the most of carbon ion radiotherapy, which is an extremely limited medical resource. Intratumoral oxygen levels, radiation-induced cellular apoptosis, the capacity to repair DNA double-strand breaks, and the mutational status of tumor protein p53 and epidermal growth factor receptor genes are all associated with X-ray sensitivity. Assays for these factors are useful in the identification of X-ray-resistant tumors for which carbon ion radiotherapy would be beneficial. Research aimed at optimizing treatments based on carbon ion radiotherapy is also important. This includes assessment of dose fractionation, normal tissue toxicity, tumor cell motility, and bystander effects. Furthermore, the efficacy of carbon ion radiotherapy will likely be enhanced by research into combined treatment with other modalities such as chemotherapy. Several clinically available chemotherapeutic drugs (carboplatin, paclitaxel, and etoposide) and drugs at the developmental stage (Wee-1 and heat shock protein 90 inhibitors) show a sensitizing effect on tumor cells treated with carbon ions. Additionally, the efficacy of carbon ion radiotherapy can be improved by

  3. Proton Radiotherapy for Pediatric Ewing's Sarcoma: Initial Clinical Outcomes

    SciTech Connect

    Rombi, Barbara; DeLaney, Thomas F.; MacDonald, Shannon M.; Huang, Mary S.; Ebb, David H.; Liebsch, Norbert J.; Raskin, Kevin A.; Yeap, Beow Y.; Marcus, Karen J.; Tarbell, Nancy J.; Yock, Torunn I.

    2012-03-01

    Purpose: Proton radiotherapy (PT) has been prescribed similarly to photon radiotherapy to achieve comparable disease control rates at comparable doses. The chief advantage of protons in this setting is to reduce acute and late toxicities by decreasing the amount of normal tissue irradiated. We report the preliminary clinical outcomes including late effects on our pediatric Ewing's sarcoma patients treated with PT at the Francis H. Burr Proton Therapy Center at Massachusetts General Hospital (Boston, MA). Methods and Materials: This was a retrospective review of the medical records of 30 children with Ewing's sarcoma who were treated with PT between April 2003 and April 2009. Results: A total of 14 male and 16 female patients with tumors in several anatomic sites were treated with PT at a median age of 10 years. The median dose was 54 Gy (relative biological effectiveness) with a median follow-up of 38.4 months. The 3-year actuarial rates of event-free survival, local control, and overall survival were 60%, 86%, and 89%, respectively. PT was acutely well tolerated, with mostly mild-to-moderate skin reactions. At the time of writing, the only serious late effects have been four hematologic malignancies, which are known risks of topoisomerase and anthracyline exposure. Conclusions: Proton radiotherapy was well tolerated, with few adverse events. Longer follow-up is needed to more fully assess tumor control and late effects, but the preliminary results are encouraging.

  4. Radiotherapy Adapted to Spatial and Temporal Variability in Tumor Hypoxia

    SciTech Connect

    Sovik, Aste; Malinen, Eirik . E-mail: emalinen@fys.uio.no; Skogmo, Hege K.; Bentzen, Soren M.; Bruland, Oyvind S.; Olsen, Dag Rune

    2007-08-01

    Purpose: To explore the feasibility and clinical potential of adapting radiotherapy to temporal and spatial variations in tumor oxygenation. Methods and Materials: Repeated dynamic contrast enhanced magnetic resonance (DCEMR) images were taken of a canine sarcoma during the course of fractionated radiation therapy. The tumor contrast enhancement was assumed to represent the oxygen distribution. The IMRT plans were retrospectively adapted to the DCEMR images by employing tumor dose redistribution. Optimized nonuniform tumor dose distributions were calculated and compared with a uniform dose distribution delivering the same integral dose to the tumor. Clinical outcome was estimated from tumor control probability (TCP) and normal tissue complication probability (NTCP) modeling. Results: The biologically adapted treatment was found to give a substantial increase in TCP compared with conventional radiotherapy, even when only pretreatment images were used as basis for the treatment planning. The TCP was further increased by repeated replanning during the course of treatment, and replanning twice a week was found to give near optimal TCP. Random errors in patient positioning were found to give a small decrease in TCP, whereas systematic errors were found to reduce TCP substantially. NTCP for the adapted treatment was similar to or lower than for the conventional treatment, both for parallel and serial normal tissue structures. Conclusion: Biologically adapted radiotherapy is estimated to improve treatment outcome of tumors having spatial and temporal variations in radiosensitivity.

  5. Expectations and quality of life of cancer patients undergoing radiotherapy.

    PubMed Central

    Koller, M; Lorenz, W; Wagner, K; Keil, A; Trott, D; Engenhart-Cabillic, R; Nies, C

    2000-01-01

    Expectations, real or false, affect the way patients respond to their illnesses. We assessed therapy-related expectations in relation to global quality of life in 55 cancer patients before and after radiotherapy. Factor analysis indicated that therapy-related expectations come into three broad categories--pain/emotional control, healing and tumour/symptom control. 35 patients expected 'healing' even though curative treatment was intended in only 19 and all patients had been fully informed. The expectation of healing was associated with high quality of life, and the same was true of perception of healing after radiotherapy. In the group as a whole, quality of life was little altered by radiotherapy, but it became substantially worse in those patients who had expected healing but perceived that this had failed, even though physician-assessed Karnofsky status did not change. These findings indicate that the expectation of healing, in cancer patients, is a component of a good global quality of life, whereas more limited expectations (pain control, tumour control) relate to lower quality of life. Patients' expectations deserve further study as a novel approach to improving care. PMID:11193059

  6. Botanicals: an alternative remedy to radiotherapy-induced dysuria.

    PubMed

    Jaladat, Amir Mohammad; Atarzadeh, Fatemeh; Rezaeizadeh, Hossein; Mofid, Bahram; Mosalaie, Ahmad; Farhan, Farshid; Amin, Gholamreza

    2015-02-01

    Everyday, many patients get radiotherapy for prostatic, rectal, uterine cervix and other pelvic organs cancer. Dysuria is common in pelvic, especially prostate radiotherapy, but there is not any established and confirmed treatment for this therapeutic side effect. Therefore, an alternative therapeutic method, using herbal preparation, may be an effective solution. This study seeks a defensible suggestion in Iranian Traditional Medicine (ITM). In ITM, a few medicinal herbs such as Plantago psyllium, Cydonia oblonga, Portulaca oleracea and some species of Malvaceae and Cucurbitaceae family are indicated in treating dysuria secondary to urethral moisturizing layer defect and inflammatory disorders. Most of these herbs have mucilaginous characteristics and tissue regeneration ability. This choice can be an appropriate one for radiotherapy-induced dysuria as it is produced by a similar pathophysiology with bladder cell layer injury and urethritis. Pharmacological properties such as anti-oxidant, anti-inflammatory, and anti-ulcerogenic activity of the offered herbs make its use justifiable. In lack of sufficient clinical trials to clarify the clinical outcome, further clinical investigation seems to be necessary. PMID:25637157

  7. Improving external beam radiotherapy by combination with internal irradiation.

    PubMed

    Dietrich, A; Koi, L; Zöphel, K; Sihver, W; Kotzerke, J; Baumann, M; Krause, M

    2015-07-01

    The efficacy of external beam radiotherapy (EBRT) is dose dependent, but the dose that can be applied to solid tumour lesions is limited by the sensitivity of the surrounding tissue. The combination of EBRT with systemically applied radioimmunotherapy (RIT) is a promising approach to increase efficacy of radiotherapy. Toxicities of both treatment modalities of this combination of internal and external radiotherapy (CIERT) are not additive, as different organs at risk are in target. However, advantages of both single treatments are combined, for example, precise high dose delivery to the bulk tumour via standard EBRT, which can be increased by addition of RIT, and potential targeting of micrometastases by RIT. Eventually, theragnostic radionuclide pairs can be used to predict uptake of the radiotherapeutic drug prior to and during therapy and find individual patients who may benefit from this treatment. This review aims to highlight the outcome of pre-clinical studies on CIERT and resultant questions for translation into the clinic. Few clinical data are available until now and reasons as well as challenges for clinical implementation are discussed.

  8. Patient setup for PET/CT acquisition in radiotherapy planning.

    PubMed

    Coffey, Mary; Vaandering, Aude

    2010-09-01

    PET/CT imaging modalities have been shown to be useful in the diagnosis, staging, and monitoring of malignant diseases. Its inclusion into the treatment planning process is now central to modern radiotherapy practice. However, it is essential to be cognisant of the factors that are necessary in order to ensure that the acquired images are consistent with the requirements for both treatment planning and treatment delivery. Essential parameters required in image acquisition for radiotherapy planning and treatment include consistencies of table tops and the use of laser light for patient set-up. But they also include the accurate definition of the patient's initial positioning and the use of proper immobilization devices in the radiotherapy department. While determining this optimum set-up, patient psychological factors and limitations that may be due to the subsequent use of PET/CT for planning purposes need to be taken into account. Furthermore, patient set-up data need to be properly recorded and transmitted to the imaging departments. To ensure the consistency of patient set-up, the radiation therapist should ideally be directly involved in informing and positioning the patient on the PET/CT. However, a proper exchange of patient-related information can also be achieved by a close liaison between the two departments and by the use of clear detailed protocols per type of patient set-up and/or per localization of tumour site. PMID:20727605

  9. Energy Modulated Photon Radiotherapy: A Monte Carlo Feasibility Study

    PubMed Central

    Zhang, Ying; Feng, Yuanming; Ming, Xin

    2016-01-01

    A novel treatment modality termed energy modulated photon radiotherapy (EMXRT) was investigated. The first step of EMXRT was to determine beam energy for each gantry angle/anatomy configuration from a pool of photon energy beams (2 to 10 MV) with a newly developed energy selector. An inverse planning system using gradient search algorithm was then employed to optimize photon beam intensity of various beam energies based on presimulated Monte Carlo pencil beam dose distributions in patient anatomy. Finally, 3D dose distributions in six patients of different tumor sites were simulated with Monte Carlo method and compared between EMXRT plans and clinical IMRT plans. Compared to current IMRT technique, the proposed EMXRT method could offer a better paradigm for the radiotherapy of lung cancers and pediatric brain tumors in terms of normal tissue sparing and integral dose. For prostate, head and neck, spine, and thyroid lesions, the EMXRT plans were generally comparable to the IMRT plans. Our feasibility study indicated that lower energy (<6 MV) photon beams could be considered in modern radiotherapy treatment planning to achieve a more personalized care for individual patient with dosimetric gains. PMID:26977413

  10. Stereotactic fractionated radiotherapy for the treatment of benign meningiomas

    SciTech Connect

    Candish, Charles; McKenzie, Michael . E-mail: mmckenzi@bccancer.bc.edu; Clark, Brenda G.; Ma, Roy; Lee, Richard; Vollans, Emily; Robar, James; Gete, Ermias; Martin, Monty

    2006-11-15

    Purpose: To assess the use of stereotactic fractionated radiotherapy (SRT) for the treatment of meningiomas. Methods and Materials: Between April 1999 and October 2004, 38 patients underwent SRT. Of 34 patients (36 tumors) assessed, the median age was 53 years. The indication was primary treatment in 26 cases (no histology) and postoperative in 10 cases. The most common sites were cavernous sinus (17), optic nerve (6), and cerebellopontine angle (5). The median gross target volume and planning target volume were 8.9 cm{sup 3} and 18.9 cm{sup 3}, respectively. Stereotactic treatment was delivered with 6-MV photons with static conformal fields (custom-made blocks, 9 patients, and micromultileaf collimator, 25 patients). Median number of fields was six. The median dose prescribed was 50 Gy (range, 45-50.4 Gy) in 28 fractions. The median homogeneity and conformality indices were 1.1 and 1.79, respectively. Results: Treatment was well tolerated. Median follow-up was 26 months with 100% progression-free survival. One patient developed an area of possible radionecrosis related to previous radiotherapy, and 2 men developed mild hypogonadism necessitating testosterone replacement. The vision of 5 of 6 patients with optic pathway meningiomas improved or remained static. Conclusions: Stereotactic fractionated radiotherapy for the treatment of meningiomas is practical, and with early follow-up, seems to be effective.

  11. Improving external beam radiotherapy by combination with internal irradiation

    PubMed Central

    Koi, L; Zöphel, K; Sihver, W; Kotzerke, J; Baumann, M; Krause, M

    2015-01-01

    The efficacy of external beam radiotherapy (EBRT) is dose dependent, but the dose that can be applied to solid tumour lesions is limited by the sensitivity of the surrounding tissue. The combination of EBRT with systemically applied radioimmunotherapy (RIT) is a promising approach to increase efficacy of radiotherapy. Toxicities of both treatment modalities of this combination of internal and external radiotherapy (CIERT) are not additive, as different organs at risk are in target. However, advantages of both single treatments are combined, for example, precise high dose delivery to the bulk tumour via standard EBRT, which can be increased by addition of RIT, and potential targeting of micrometastases by RIT. Eventually, theragnostic radionuclide pairs can be used to predict uptake of the radiotherapeutic drug prior to and during therapy and find individual patients who may benefit from this treatment. This review aims to highlight the outcome of pre-clinical studies on CIERT and resultant questions for translation into the clinic. Few clinical data are available until now and reasons as well as challenges for clinical implementation are discussed. PMID:25782328

  12. [3rd Hungarian Breast Cancer Consensus Conference - Radiotherapy Guidelines].

    PubMed

    Polgár, Csaba; Kahán, Zsuzsanna; Csejtei, András; Gábor, Gabriella; Landherr, László; Mangel, László; Mayer, Árpád; Fodor, János

    2016-09-01

    The radiotherapy expert panel revised and updated the radiotherapy (RT) guidelines accepted in 2009 at the 2nd Hungarian Breast Cancer Consensus Conference based on new scientific evidence. Radiotherapy of the conserved breast is indicated in ductal carcinoma in situ (St. 0), as RT decreases the risk of local recurrence by 60%. In early stage (St. I-II) invasive breast cancer RT remains a standard treatment following breast conserving surgery. However, in elderly (≥70 years) patients with stage I, hormone receptor positive tumour hormonal therapy without RT can be considered. Hypofractionated (15×2.67 Gy) whole breast irradiation and for selected cases accelerated partial breast irradiation are validated treatment alternatives of conventional (25×2 Gy) whole breast irradiation. Following mastectomy RT significantly decreases the risk of locoregional recurrence and improves overall survival of patients having 1 to 3 (pN1a) or ≥4 (pN2a, pN3a) positive axillary lymph nodes. In selected cases of patients with 1 to 2 positive sentinel lymph nodes axillary dissection can be omitted and substituted with axillary RT. After neoadjuvant chemotherapy (NAC) followed by breast conserving surgery whole breast irradiation is mandatory, while after NAC followed by mastectomy locoregional RT should be given in cases of initial stage III-IV and ypN1 axillary status. PMID:27579722

  13. Gold Coated Lanthanide Phosphate Nanoparticles for Targeted Alpha Generator Radiotherapy

    PubMed Central

    McLaughlin, Mark F.; Woodward, Jonathan; Boll, Rose A.; Wall, Jonathan S.; Rondinone, Adam J.; Kennel, Stephen J.; Mirzadeh, Saed; Robertson, J. David

    2013-01-01

    Targeted radiotherapies maximize cytotoxicty to cancer cells. In vivo α-generator targeted radiotherapies can deliver multiple α particles to a receptor site dramatically amplifying the radiation dose delivered to the target. The major challenge with α-generator radiotherapies is that traditional chelating moieties are unable to sequester the radioactive daughters in the bioconjugate which is critical to minimize toxicity to healthy, non-target tissue. The recoil energy of the 225Ac daughters following α decay will sever any metal-ligand bond used to form the bioconjugate. This work demonstrates that an engineered multilayered nanoparticle-antibody conjugate can deliver multiple α radiations and contain the decay daughters of 225Ac while targeting biologically relevant receptors in a female BALB/c mouse model. These multi-shell nanoparticles combine the radiation resistance of lanthanide phosphate to contain 225Ac and its radioactive decay daughters, the magnetic properties of gadolinium phosphate for easy separation, and established gold chemistry for attachment of targeting moieties. PMID:23349921

  14. Radioiodine and radiotherapy in the management of thyroid cancers

    SciTech Connect

    Simpson, W.J. )

    1990-06-01

    Radioiodine is an important adjuvant treatment in the management of resectable papillary and follicular thyroid cancers in all patients except those with the best prognostic features. External radiation is also an important adjuvant therapy in these patients, especially those with tumors that extend beyond the thyroid gland and invade the trachea, esophagus, nerves, and blood vessels; it is especially important in treating patients whose tumors do not concentrate radioiodine. Radioiodine may be curative in patients with microscopic distant metastases demonstrated by radioiodine scanning. Even unresectable primary papillary and follicular cancers may be eradicated by combined therapy with radioiodine and radiotherapy. Radioiodine plays no significant role in the treatment of medullary or anaplastic thyroid cancers, but external radiation may eradicate microscopic thyroid bed or nodal disease when persistent disease is indicated by elevated calcitonin levels in medullary thyroid cancer patients. Anaplastic thyroid cancers are usually unresectable and are not eradicated by conventional radiotherapy or by any of the novel radiation techniques, with or without chemotherapy. In all types of thyroid cancer, external radiotherapy may produce beneficial palliative results in patients with distant metastases, but the use of radioiodine should always be explored in papillary and follicular thyroid cancer patients. 30 references.

  15. Radiotherapy of advanced laryngeal cancer using three small fractions daily

    SciTech Connect

    Bradley, P.J.; Morgan, D.A. )

    1991-06-01

    Since 1983, the authors have treated advanced (UICC stages 3 and 4) squamous carcinomas of the larynx by primary radiotherapy, using three small fractions a day, 3-4 h interfraction interval, 5 days per week. The early patients received doses per fraction of 1.5 Gy, and a total dose of approximately 70 Gy, given as a split-course over 6 to 7 weeks. While overall tumor control and laryngeal preservation was good, a number of severe late radiation reactions were seen. The schedule was then modified, with a reduction in the fraction size to 1.1 Gy, the total dose to 60 Gy, and the overall time to 4 weeks, with omission of the mid-treatment split. Since 1986, we have treated 26 patients in this way. Acute reactions are brisk, but rapidly healing. Loco-regional control was achieved in 22 patients, only one of whom has relapsed to date, in a solitary node, salvaged by radical neck dissection. Four have died of uncontrolled loco-regional malignancy, and three of intercurrent disease while in clinical remission. No serious late morbidity has been observed in surviving patients, and vocal quality is good in the majority. These results suggest that this hyperfractionated and accelerated radiotherapy schedule may offer an acceptable nonsurgical, voice-preserving treatment for advanced laryngeal carcinoma; it can be used in a normally working radiotherapy department.

  16. Radiotherapy and the potential exploitation of bystander effects.

    PubMed

    Mothersill, C E; Moriarty, M J; Seymour, C B

    2004-02-01

    Radiation-induced bystander effects are the subject of intense investigation in radiation protection. The effects predominate at low doses and have been discussed mainly in terms of the impact on low-dose risk assessment. Possible therapeutic implications have been alluded to, but not discussed in any detail. The purpose of this review was to consider bystander biology in areas of major importance or interest in radiotherapy. These include consideration of radiation-induced bystander effects during the cell cycle, under hypoxic conditions, when fractionated therapy modalities are used, or when combined radiochemotherapy is given. Also discussed are individual variations in toxicity of bystander factors and normal tissue "collateral" damage. The importance of considering the tumor in the context of the organ, and even the organism that supports it, is also discussed. Direct clinical radiotherapy studies that consider bystander effects are not in the public domain at the time of writing, but many in vitro studies are available that are relevant; some preliminary animal data have also been published. Because radiation-induced bystander effects appear to challenge many of the central assumptions that underlie radiotherapy practice, it is important to consider what unexplored treatment avenues might result from a consideration of these effects. The final part of this paper is devoted to this point. PMID:14751530

  17. Toxic Epidermal Necrolysis in Polymedicated Patient Treated With Radiotherapy

    PubMed Central

    Pérez-Calderón, Remedios; Corrales-Vargas, Silvia; Jiménez-Ferrera, Gloria; Rodríguez-Nevado, Isabel; Díaz-Delgado, Mario

    2015-01-01

    Temozolomide is an oral alkylating agent indicated for the treatment of patients with glioblastoma multiforme concomitantly with radiotherapy and subsequently as monotherapy treatment. We report the case of a patient who developed toxic epidermal necrolysis (TEN) while she was being treated with chemoradiotherapy and several drugs. Cutaneous tests were performed with the drugs involved with negative result. Although the occurrence of TEN contraindicates suspected drug readministration, we based the decision to perform the controlled administration of temozolomide on the following reasons: (1) the poor prognosis of the underlying disease, (2) the lack of therapeutic alternatives, (3) the suspicion that other drugs taken by the patient simultaneously may be responsible (as anticonvulsants and trimethoprim sulfamethoxazole [TMP-SMX]), and (4) temozolomide was the first choice for treating the patient's disease. The administration of a cumulative dose of 60 mg of temozolomide caused a slight skin reaction. Given this result, we conducted controlled administration of other drugs involved. Dexamethasone, codeine, omeprazole and levetiracetam were well tolerated. However, TMP-SMX produced a similar reaction to that caused by temozolomide. In conclusion, we present the first case of TEN induced by temozolomide and TMP-SMX associated with cranial radiotherapy confirmed by controlled administration. Radiotherapy in combination with these drugs could have favored TEN, as some authors have postulated, but we cannot prove this. PMID:25729629

  18. Radiotherapy Combined With Androgen Deprivation for Bone Oligometastases After Primary Curative Radiotherapy for Prostate Cancer

    PubMed Central

    Wu, Jun-Xin; Lin, Li-Mei; He, Jun-Yan; Hong, Liang; Li, Jin-Luan

    2016-01-01

    Abstract To evaluate the effects and toxicity of radiotherapy (RT) combined with androgen deprivation (AD) for bone oligometastases after primary curative RT for prostate cancer (PCa). We retrospectively analyzed 30 consecutively treated PCa patients with bone oligometastases from April 2005 to July 2014. All patients underwent RT combined with AD for oligometastatic bones after curative RT for PCa. Measured outcomes included overall survival (OS) rate, local control (LC), progression-free survival (PFS), pain relief, and toxicities. Statistical analysis was performed with SPSS17.0. The median follow-up was 32.5 months (range, 0.6–50.3). The 3-year PFS and OS rates were 22.8% (95% CI, 13.4–37.5%) and 69% (95% CI, 51.7–81.1%), respectively. The number of bone oligometastases and RT schedule were found to be significantly associated with OS on univariate analysis (P < 0.05, respectively). The 3-year OS for patients with 1 and >1 metastases was 78.8% versus 42.2%, respectively (P = 0.037). The long-course RT was associated with better 3-year OS compared with short-course (76.4% vs 44.1%, P = 0.03). A total of 15 (83.3%, 15/18) patients achieved pain relief. No grade 3 toxicity was observed. Long-course RT combined with ADT was effective and well-tolerated in PCa patients with bone oligometastases after curative RT for PCa. Further randomized controlled trials are needed to corroborate the findings. PMID:26871838

  19. [Duokangjiasu combined with radiotherapy in the treatment of 32 nasopharyngeal carcinoma (NPC) patients].

    PubMed

    Li, Q Q

    1988-07-01

    The results of 32 NPC patients treated by duokangjiasu combined with radiotherapy or radiotherapy alone are reported. Subjects were divided into two groups, combined and control groups with 16 patients each. The results showed that the patients treated with combination of duokangjiasu and radiotherapy had less decrease in blood IgM level than the controls treated with radiotherapy alone. Therefore, it indicates that duokangjiasu may stabilized immune function in vivo at a normal level and remarkably accelerate the resolution or eradication of the primary focus in the nasopharynx. PMID:3248490

  20. Role of Radiotherapy and Newer Techniques in the Treatment of GI Cancers.

    PubMed

    Hajj, Carla; Goodman, Karyn A

    2015-06-01

    The role of radiotherapy in multidisciplinary treatment of GI malignancies is well established. Recent advances in imaging as well as radiotherapy planning and delivery techniques have made it possible to target tumors more accurately while sparing normal tissues. Intensity-modulated radiotherapy is an advanced method of delivering radiation using cutting-edge technology to manipulate beams of radiation. The role of intensity-modulated radiotherapy is growing for many GI malignancies, such as cancers of the stomach, pancreas, esophagus, liver, and anus. Stereotactic body radiotherapy is an emerging treatment option for some GI tumors such as locally advanced pancreatic cancer and primary or metastatic tumors of the liver. Stereotactic body radiotherapy requires a high degree of confidence in tumor location and subcentimeter accuracy of the delivered dose. New image-guided techniques have been developed to overcome setup uncertainties at the time of treatment, including real-time imaging on the linear accelerator. Modern imaging techniques have also allowed for more accurate pretreatment staging and delineation of the primary tumor and involved sites. In particular, magnetic resonance imaging and positron emission tomography scans can be particularly useful in radiotherapy planning and assessing treatment response. Molecular biomarkers are being investigated as predictors of response to radiotherapy with the intent of ultimately moving toward using genomic and proteomic determinants of therapeutic strategies. The role of all of these new approaches in the radiotherapeutic management of GI cancers and the evolving role of radiotherapy in these tumor sites will be highlighted in this review. PMID:25918298

  1. Osteoradionecrosis Following Carbon Ion Radiotherapy: Case History Report of a Soft Palate Defect.

    PubMed

    Oki, Meiko; Kanazaki, Ayako; Taniguchi, Hisashi

    2016-01-01

    Carbon ion radiotherapy, a form of charged particle radiotherapy that has been used to treat various inoperable and radio-resistant tumors, has been associated with less severe late effects than conventional radiotherapy. A 63-year-old woman with a soft palate defect received carbon ion radiotherapy (total dose: 64 Gray equivalents). Several late effects were observed, and osteoradionecrosis was observed not only on the tumor side but also on the other side and gradually expanded during maxillofacial prosthetic rehabilitation. While the definitive prosthesis improved her speech and eating ability, careful adjustments and close follow-up should continue with respect to postradiation effects. PMID:27611746

  2. Intensified autophagy compromises the efficacy of radiotherapy against prostate cancer

    SciTech Connect

    Koukourakis, Michael I.

    2015-05-29

    Introduction: Radiotherapy is an equivalent alternative or complement to radical prostatectomy, with high therapeutic efficacy. High risk patients, however, experience high relapse rates, so that research on radio-sensitization is the most evident route to improve curability of this common disease. Materials and methods: In the current study we investigated the autophagic activity in a series of patients with localized prostate tumors treated with radical radiotherapy, using the LC3A and the LAMP2a proteins as markers of autophagosome and lysosome cellular content, respectively. The role of autophagy on prostate cancer cell line resistance to radiation was also examined. Results: Using confocal microscopy on tissue biopsies, we showed that prostate cancer cells have, overall, high levels of LC3A and low levels of LAMP2a compared to normal prostate glands. Tumors with a ‘highLC3A/lowLAMP2a’ phenotype, suggestive of intensified lysosomal consumption, had a significantly poorer biochemical relapse free survival. The PC3 radioresistant cell line sustained remarkably its autophagic flux ability after radiation, while the DU145 radiosensitive one experiences a prolonged blockage of the autophagic process. This was assessed with aggresome accumulation detection and LC3A/LAMP2a double immunofluorescence, as well as with sequestrosome/p62 protein detection. By silencing the LC3A or LAMP2a expression, both cell lines became more sensitive to escalated doses of radiation. Conclusions: High base line autophagy activity and cell ability to sustain functional autophagy define resistance of prostate cancer cells to radiotherapy. This can be reversed by blocking up-regulated components of the autophagy pathway, which may prove of importance in the field of clinical radiotherapy. - Highlights: • High LC3A and low LAMP2a levels is a frequent expression pattern of prostate carcinoma. • This pattern of intensified autophagic flux relates with high relapse rates after

  3. Locally Advanced Stage IV Squamous Cell Carcinoma of the Head and Neck: Impact of Pre-Radiotherapy Hemoglobin Level and Interruptions During Radiotherapy

    SciTech Connect

    Rades, Dirk Stoehr, Monika; Kazic, Nadja; Hakim, Samer G.; Walz, Annette; Schild, Steven E.; Dunst, Juergen

    2008-03-15

    Purpose: Stage IV head and neck cancer patients carry a poor prognosis. Clear understanding of prognostic factors can help to optimize care for the individual patient. This study investigated 11 potential prognostic factors including pre-radiotherapy hemoglobin level and interruptions during radiotherapy for overall survival (OS), metastases-free survival (MFS), and locoregional control (LC) after radiochemotherapy. Methods and Materials: Eleven factors were investigated in 153 patients receiving radiochemotherapy for Stage IV squamous cell head and neck cancer: age, gender, Karnofsky performance score (KPS), tumor site, grading, T stage, N stage, pre-radiotherapy hemoglobin level, surgery, chemotherapy type, and interruptions during radiotherapy >1 week. Results: On multivariate analysis, improved OS was associated with KPS 90-100 (relative risk [RR], 2.36; 95% confidence interval [CI], 1.20-4.93; p = .012), hemoglobin {>=}12 g/dL (RR, 1.88; 95% CI, 1.01-3.53; p = .048), and no radiotherapy interruptions (RR, 2.59; 95% CI, 1.15-5.78; p = .021). Improved LC was significantly associated with lower T stage (RR, 2.17; 95% CI, 1.16-4.63; p = .013), hemoglobin {>=}12 g/dL (RR, 4.12; 95% CI, 1.92-9.09; p < .001), surgery (RR, 2.67; 95% CI, 1.28-5.88; p = .008), and no radiotherapy interruptions (RR, 3.32; 95% CI, 1.26-8.79; p = .015). Improved MFS was associated with KPS 90-100 (RR, 3.41; 95% CI, 1.46-8.85; p = .012). Conclusions: Significant predictors for outcome in Stage IV head and neck cancer were performance status, stage, surgery, pre-radiotherapy hemoglobin level, and interruptions during radiotherapy >1 week. It appears important to avoid anemia and radiotherapy interruptions to achieve the best treatment results.

  4. [Radiotherapy in cancers of the oesophagus, the gastric cardia and the stomach].

    PubMed

    Créhange, G; Huguet, F; Quero, L; N'Guyen, T V; Mirabel, X; Lacornerie, T

    2016-09-01

    Localized oesophageal and gastric cancers have a poor prognosis. In oesophageal cancer, external radiotherapy combined with concomitant chemotherapy is accepted as part of the therapeutic armamentarium in a curative intent in the preoperative setting for resectable tumours; or without surgery in inoperable patients or non-resectable tumours due to wide local and/or regional extension. Data from the literature show conflicting results with no clinical evidence in favour of either a unique dose protocol or consensual target volume definition in the setting of exclusive chemoradiation. In the preoperative setting, chemoradiotherapy has become the standard in oesophageal cancer, even though there is no evidence that surgery may be beneficial in locally advanced tumours that respond to radiotherapy and chemotherapy. The main cause of failure after exclusive chemoradiotherapy in oesophageal cancer is locoregional relapse suggesting that doses and volumes usually considered may be inadequate. In gastric cancer, radiotherapy may be indicated postoperatively in patients with resected tumours that include less than D2 lymph node dissection or in the absence of perioperative chemotherapy. Preoperative chemoradiotherapy in gastric cancers is still under investigation. The evolving techniques of external radiotherapy, such as image-guided radiotherapy (IMRT) and volumetric modulated arctherapy (VMAT) have reduced the volume of lung and heart exposed to radiation, which seems to have diminished radiotherapy-related morbi-mortality rates. Given this, quality assurance for radiotherapy and protocols for radiotherapy delivery must be better standardized. This article on the indications for radiotherapy and the techniques used in oesophageal and gastric cancers is included in a special issue dedicated to national recommendations from the French society of radiation oncology (SFRO) on radiotherapy indications, planning, dose prescription, and techniques of radiotherapy delivery. PMID

  5. [Radiotherapy in cancers of the oesophagus, the gastric cardia and the stomach].

    PubMed

    Créhange, G; Huguet, F; Quero, L; N'Guyen, T V; Mirabel, X; Lacornerie, T

    2016-09-01

    Localized oesophageal and gastric cancers have a poor prognosis. In oesophageal cancer, external radiotherapy combined with concomitant chemotherapy is accepted as part of the therapeutic armamentarium in a curative intent in the preoperative setting for resectable tumours; or without surgery in inoperable patients or non-resectable tumours due to wide local and/or regional extension. Data from the literature show conflicting results with no clinical evidence in favour of either a unique dose protocol or consensual target volume definition in the setting of exclusive chemoradiation. In the preoperative setting, chemoradiotherapy has become the standard in oesophageal cancer, even though there is no evidence that surgery may be beneficial in locally advanced tumours that respond to radiotherapy and chemotherapy. The main cause of failure after exclusive chemoradiotherapy in oesophageal cancer is locoregional relapse suggesting that doses and volumes usually considered may be inadequate. In gastric cancer, radiotherapy may be indicated postoperatively in patients with resected tumours that include less than D2 lymph node dissection or in the absence of perioperative chemotherapy. Preoperative chemoradiotherapy in gastric cancers is still under investigation. The evolving techniques of external radiotherapy, such as image-guided radiotherapy (IMRT) and volumetric modulated arctherapy (VMAT) have reduced the volume of lung and heart exposed to radiation, which seems to have diminished radiotherapy-related morbi-mortality rates. Given this, quality assurance for radiotherapy and protocols for radiotherapy delivery must be better standardized. This article on the indications for radiotherapy and the techniques used in oesophageal and gastric cancers is included in a special issue dedicated to national recommendations from the French society of radiation oncology (SFRO) on radiotherapy indications, planning, dose prescription, and techniques of radiotherapy delivery.

  6. Surgical Resection Followed by Whole Brain Radiotherapy Versus Whole Brain Radiotherapy Alone for Single Brain Metastasis

    SciTech Connect

    Rades, Dirk Kieckebusch, Susanne; Haatanen, Tiina; Lohynska, Radka; Dunst, Juergen; Schild, Steven E.

    2008-04-01

    Purpose: To compare the outcome of surgical resection followed by whole brain radiotherapy (WBRT) with WBRT alone in patients treated for single brain metastasis. Methods and Materials: The data from 195 patients with single brain metastases were retrospectively evaluated. Of the 195 patients, 99 underwent resection of the metastasis followed by WBRT and 96 underwent WBRT alone. Seven additional potential prognostic factors were investigated: age, gender, Eastern Cooperative Oncology Group performance score, tumor type, interval between initial tumor diagnosis and WBRT, extracranial metastases, and recursive partitioning analysis class. Both treatment groups were well balanced for these factors. Results: On multivariate analysis, improved survival was associated with resection (relative risk [RR], 1.20; 95% confidence interval [CI], 1.11-1.31; p < 0.001), lower recursive partitioning analysis class (RR, 1.58; 95% CI, 1.22-2.06; p < 0.001), age {<=}61 years (RR, 1.79; 95% CI, 1.23-2.61; p = 0.002), Eastern Cooperative Oncology Group performance score of 0-1 (RR, 2.47; 95% CI, 1.70-3.59; p < 0.001), and the absence of extracranial metastases (RR, 1.99; 95% CI, 1.41-2.79; p < 0.001). Improved local control was associated with resection (RR, 1.25; 95% CI, 1.11-1.41; p < 0.001) and age {<=}61 years (RR, 1.77; 95% CI, 1.09-2.88; p = 0.020). Improved brain control distant from the original site was associated with lower recursive partitioning analysis class (RR, 1.65; 95% CI, 1.03-2.69; p < 0.035), age {<=}61 years (RR, 1.81; 95% CI, 1.12-2.96; p = 0.016), and the absence of extracranial metastases (RR, 2.42; 95% CI, 1.52-3.88; p < 0.001). Improved control within the entire brain was associated with surgery (RR, 1.24; 95% CI, 1.12-1.38; p < 0.001) and age {<=}61 years (RR, 1.83; 95% CI, 1.21-2.77; p = 0.004). Conclusion: In patients with a single brain metastasis, the addition of resection to WBRT improved survival, local control at the original metastatic site, and

  7. What is changing in radiotherapy for the treatment of locally advanced nonsmall cell lung cancer patients? A review.

    PubMed

    Giaj-Levra, Niccoló; Ricchetti, Francesco; Alongi, Filippo

    2016-01-01

    Radiotherapy treatment continues to have a relevant impact in the treatment of nonsmall cell cancer (NSCLC). Use of concurrent chemotherapy and radiotherapy is considered the gold standard in the treatment of locally advanced NSCLC but clinical outcomes are not satisfactory. Introduction of new radiotherapy technology and chemotherapy regimens are under investigation in this setting with the goal to improve unsatisfactory results. We report how radiotherapy is changing in the treatment of locally advanced NSCLC.

  8. Volumetric-modulated arc radiotherapy for pancreatic malignancies: Dosimetric comparison with sliding-window intensity-modulated radiotherapy and 3-dimensional conformal radiotherapy

    SciTech Connect

    Nabavizadeh, Nima Simeonova, Anna O.; Waller, Joseph G.; Romer, Jeanna L.; Monaco, Debra L.; Elliott, David A.; Tanyi, James A.; Fuss, Martin; Thomas, Charles R.; Holland, John M.

    2014-10-01

    Volumetric-modulated arc radiotherapy (VMAT) is an iteration of intensity-modulated radiotherapy (IMRT), both of which deliver highly conformal dose distributions. Studies have shown the superiority of VMAT and IMRT in comparison with 3-dimensional conformal radiotherapy (3D-CRT) in planning target volume (PTV) coverage and organs-at-risk (OARs) sparing. This is the first study examining the benefits of VMAT in pancreatic cancer for doses more than 55.8 Gy. A planning study comparing 3D-CRT, IMRT, and VMAT was performed in 20 patients with pancreatic cancer. Treatments were planned for a 25-fraction delivery of 45 Gy to a large field followed by a reduced-volume 8-fraction external beam boost to 59.4 Gy in total. OARs and PTV doses, conformality index (CI) deviations from 1.0, monitor units (MUs) delivered, and isodose volumes were compared. IMRT and VMAT CI deviations from 1.0 for the large-field and the boost plans were equivalent (large field: 0.032 and 0.046, respectively; boost: 0.042 and 0.037, respectively; p > 0.05 for all comparisons). Both IMRT and VMAT CI deviations from 1.0 were statistically superior to 3D-CRT (large field: 0.217, boost: 0.177; p < 0.05 for all comparisons). VMAT showed reduction of the mean dose to the boost PTV (VMAT: 61.4 Gy, IMRT: 62.4 Gy, and 3D-CRT: 62.3 Gy; p < 0.05). The mean number of MUs per fraction was significantly lower for VMAT for both the large-field and the boost plans. VMAT delivery time was less than 3 minutes compared with 8 minutes for IMRT. Although no statistically significant dose reduction to the OARs was identified when comparing VMAT with IMRT, VMAT showed a reduction in the volumes of the 100% isodose line for the large-field plans. Dose escalation to 59.4 Gy in pancreatic cancer is dosimetrically feasible with shorter treatment times, fewer MUs delivered, and comparable CIs for VMAT when compared with IMRT.

  9. Challenges in integrating 18FDG PET-CT into radiotherapy planning of head and neck cancer.

    PubMed

    Dandekar, P; Partridge, M; Kazi, R; Nutting, C; Harrington, K; Newbold, K

    2010-01-01

    Radiotherapy forms one of the major treatment modalities for head and neck cancers (HNC), and precision radiotherapy techniques, such as intensity-modulated radiotherapy require accurate target delineation to ensure success of the treatment. Conventionally used imaging modalities, such as X-ray computed tomography (CT) and magnetic resonance imaging are used to delineate the tumor. Imaging, such as positron emission tomography (PET)-CT, which combines the functional and anatomic modalities, is increasingly being used in the management of HNC. Currently, 18-fluorodeoxyglucose is the most commonly used radioisotope, which is accumulated in areas of high glucose uptake, such as the tumor tissue. Because most disease recurrences are within the high-dose radiotherapy volume, defining a biological target volume for radiotherapy boost is an attractive approach to improve the results. There are many challenges in employing the PET-CT for radiotherapy planning, such as patient positioning, target edge definition, and use of new PET tracers, which represent various functional properties, such as hypoxia, protein synthesis, and proliferation. The role of PET-CT for radiotherapy planning is ever expanding and more clinical data underlining the advantages and challenges in this approach are emerging. In this article, we review the current clinical evidence for the application of functional imaging to radiotherapy planning and discuss some of the current challenges and possible solutions that have been suggested to date.

  10. Radiotherapy for Management of Extremity Soft Tissue Sarcomas: Why, When, and Where?

    SciTech Connect

    Haas, Rick L.M.; DeLaney, Thomas F.; O'Sullivan, Brian; Keus, Ronald B.; Le Pechoux, Cecile; Olmi, Patricia; Poulsen, Jan-Peter; Seddon, Beatrice; Wang, Dian

    2012-11-01

    This critical review will focus on published data on the indications for radiotherapy in patients with extremity soft tissue sarcomas and its role in local control, survival, and treatment complications. The differences between pre- and postoperative radiotherapy will be discussed and consensus recommendations on target volume delineation proposed.

  11. Misonidazole and radiotherapy in lung cancer: a randomized double-blind trial

    SciTech Connect

    Mantyla, M.J.; Norman, E.M.; Ruotsalainen, P.J.; Kylmamaa, T.T.

    1982-10-01

    Forty-six patients with inoperable bronchial cancer have been treated by a fractionated course of radiotherapy with misonidazole or placebo. The main purpose of the administration of the drug to these patients was to determine tumor response and safe dosage in clinical radiotherapy. It seems possible to enhance the radiosensitivity of human squamous cell cancer by misonidazole.

  12. [Effectiveness of radiotherapy in patients with lymphogranulomatosis depending on the stage of the disease].

    PubMed

    Mendeleev, I M; Miasnikov, A A; Oleĭnik, V A

    1984-01-01

    The authors review variants of radiotherapy of patients with lymphogranulomatosis. Regard the method of irradiation with broad fields of complicated configuration as preferable. Point to the advisability of using one or another method depending on the disease stage. Describe the conditions necessary, in their opinion, for successful radiotherapy of lymphogranulomatosis patients.

  13. Factors influencing time between surgery and radiotherapy: A population based study of breast cancer patients.

    PubMed

    Katik, S; Gort, M; Jobsen, J J; Maduro, J H; Struikmans, H; Siesling, S

    2015-08-01

    This study describes variation in the time interval between surgery and radiotherapy in breast cancer (BC) patients and assesses factors at patient, hospital and radiotherapy centre (RTC) level influencing this variation. To do so, the factors were investigated in BC patients using multilevel logistic regression. The study sample consisted of 15,961 patients from the Netherlands Cancer Registry at 79 hospitals and 19 (RTCs) with breast-conserving surgery or mastectomy directly followed by radiotherapy. The percentage of patients starting radiotherapy ≤42 days varied from 14% to 94%. Early year of incidence, higher age, higher stage, mastectomy, higher ASA category and no availability of radiotherapy facilities were significantly associated with a longer time interval between radiotherapy and surgery. More patients received radiotherapy ≤42 days in hospitals with on-site radiotherapy facilities (OR 1.36, p = 0.024). Among the remainder, significant variation was found at the RTC level (11.1%, σ(2) = 0.254, SE 0.054), and at the hospital level (6.4% σ2 = 0.443, SE 0.163) (ICC 0.064). The significant delay and unexplained variance remaining at the RCT and hospital level suggests delays caused by the patient referral pathway from hospital to RCT, and indicates potential for improvement at both levels.

  14. [What type of hypofractionated radiotherapy of primary tumours in palliative care?].

    PubMed

    Bourgier, C; Charissoux, M; Boisselier, P; Ducteil, A; Azria, D

    2015-10-01

    Palliative radiation therapy is well-known in the setting of metastatic lesions (haemostatic, analgesic, anti-inflammatory aims, etc.). Palliative primary tumour radiotherapy is less studied. Here we propose a review of palliative indications of primary tumours, the most studied in the literature, and their radiotherapy modalities (target volumes and fractionation).

  15. Ultrasonographic changes in the normal and malignant prostate after definitive radiotherapy

    SciTech Connect

    Egawa, S.; Carter, S.S.; Wheeler, T.M.; Scardino, P.T. )

    1989-11-01

    As treatments for early localized prostate cancer come under closer scrutiny, the fundamental problem of documenting the success of radiotherapy becomes more obvious. Currently, no satisfactory method exists to determine tumor viability after radiotherapy. Transrectal ultrasonography is particularly valuable for monitoring the response of prostate cancer to radiotherapy. Persistent cancer retains its hypoechoic appearance after definitive radiotherapy. Hypoechoic lesions greater than 5 mm in diameter found more than 12 months after radiotherapy should be suspected of representing persistent local disease. In our study, albeit in a selected group of patients undergoing salvage radical prostatectomy, 92 per cent of such findings were associated with what we interpreted as viable tumor by light microscopy. Ultrasound-guided biopsy should be considered in such circumstances. The persistence of hypoechoic lesions in more than 65 per cent of patients 12 to 36 months after radiotherapy also suggests that local treatment failure may be underestimated by digital rectal examination and random digitally guided biopsy. Serial measurement of the diameter of hypoechoic lesions may provide a valuable indicator of progress in an individual patient. Patients with enlarging foci of tumor within the prostate after radiotherapy might be selected for biopsy and further treatment. If such a policy is employed, it is likely that a higher incidence of persistent cancer will be found after radiotherapy than has previously been discovered by random digitally guided biopsy.

  16. Combinations of Radiotherapy and Immunotherapy for Melanoma: A Review of Clinical Outcomes

    PubMed Central

    Barker, Christopher A.; Postow, Michael A.

    2015-01-01

    Radiotherapy has long played a role in the management of melanoma. Recent advances have also demonstrated the efficacy of immunotherapy in the treatment of melanoma. Preclinical data suggest a biologic interaction between radiotherapy and immunotherapy. Several clinical studies corroborate these findings. This review will summarize the outcomes of studies reporting on patients with melanoma treated with a combination of radiotherapy and immunotherapy. Vaccine therapies often use irradiated melanoma cells, and may be enhanced by radiotherapy. The cytokines interferon-alpha and interleukin-2 have been combined with radiotherapy in several small studies, with some evidence suggesting increased toxicity and/or efficacy. Ipilimumab, a monoclonal antibody which blocks cytotoxic T-lymphocyte antigen-4, has been combined with radiotherapy in several notable case studies and series. Finally, pilot studies of adoptive cell transfer have suggested radiotherapy may improve the efficacy of treatment. The review will demonstrate that the combination of radiotherapy and immunotherapy has been reported in several notable case studies, series and clinical trials. These clinical results suggest interaction and the need for further study. PMID:24661650

  17. Prognostic factors in the radiotherapy of Graves' ophthalmopathy

    SciTech Connect

    Petersen, I.A.; Kriss, J.P.; McDougall, I.R.; Donaldson, S.S. )

    1990-08-01

    Between April 1968 and February 1988, 311 patients with symptomatic and progressive Graves' ophthalmopathy were treated with megavoltage orbital radiotherapy. The patients were divided into three groups: I treated with 20 Gy/2 weeks; II treated with 30 Gy/3 weeks, and III received 20 Gy/2 weeks. The degree of eye involvement was evaluated numerically before and after therapy for each of five parameters: soft tissue signs, proptosis, eye muscle impairment, corneal involvement, and sight loss. Pre-treatment and current thyroid diagnosis and status were also noted. To evaluate the effects of radiotherapy alone, follow-up was terminated at the time any eye surgery was done; for those not treated surgically the minimum follow-up was 12 months. Because there were significant demographic differences between the patient groups, the results of each group were analyzed separately. A stepwise linear regression analysis was performed to determine if there were any significant variables affecting outcome. Based on these data formulae were derived which enable outcome to be predicted in any patient. Before therapy more than 90% of patients in all groups had soft tissue and eye muscle involvement, whereas 65-75% had proptosis and about half 50% had some degree of sight loss. Radiotherapy arrested progression of ophthalmic parameters in all but 1-6% of the patients. Objective and symptomatic improvement was noted for all parameters assessed, but there was marked individual variability. The best responses were noted for soft tissue, corneal involvement, and sight loss; however over half the patients had some improvement in eye muscle function and proptosis. Factors which resulted in less favorable outcome included male gender, advanced age, need for concurrent therapy for hyperthyroidism, and no history of hyperthyroidism. No complications have been observed.

  18. The role of PET/CT scanning in radiotherapy planning.

    PubMed

    Jarritt, P H; Carson, K J; Hounsell, A R; Visvikis, D

    2006-09-01

    The introduction of functional data into the radiotherapy treatment planning process is currently the focus of significant commercial, technical, scientific and clinical development. The potential of such data from positron emission tomography (PET) was recognized at an early stage and was integrated into the radiotherapy treatment planning process through the use of image fusion software. The combination of PET and CT in a single system (PET/CT) to form an inherently fused anatomical and functional dataset has provided an imaging modality which could be used as the prime tool in the delineation of tumour volumes and the preparation of patient treatment plans, especially when integrated with virtual simulation. PET imaging typically using 18F-Fluorodeoxyglucose (18F-FDG) can provide data on metabolically active tumour volumes. These functional data have the potential to modify treatment volumes and to guide treatment delivery to cells with particular metabolic characteristics. This paper reviews the current status of the integration of PET and PET/CT data into the radiotherapy treatment process. Consideration is given to the requirements of PET/CT data acquisition with reference to patient positioning aids and the limitations imposed by the PET/CT system. It also reviews the approaches being taken to the definition of functional/tumour volumes and the mechanisms available to measure and include physiological motion into the imaging process. The use of PET data must be based upon a clear understanding of the interpretation and limitations of the functional signal. Protocols for the implementation of this development remain to be defined, and outcomes data based upon clinical trials are still awaited. PMID:16980683

  19. Intraoperative Radiotherapy for Parotid Cancer: A Single-Institution Experience

    SciTech Connect

    Zeidan, Youssef H.; Shiue, Kevin; Weed, Daniel; Johnstone, Peter A.; Terry, Colin; Freeman, Stephen; Krowiak, Edward; Borrowdale, Robert; Huntley, Tod; Yeh, Alex

    2012-04-01

    Purpose: Our practice policy has been to provide intraoperative radiotherapy (IORT) at resection to patients with head-and-neck malignancies considered to be at high risk of recurrence. The purpose of the present study was to review our experience with the use of IORT for primary or recurrent cancer of the parotid gland. Methods and Materials: Between 1982 and 2007, 96 patients were treated with gross total resection and IORT for primary or recurrent cancer of the parotid gland. The median age was 62.9 years (range, 14.3-88.1). Of the 96 patients, 33 had previously undergone external beam radiotherapy as a component of definitive therapy. Also, 34 patients had positive margins after surgery, and 40 had perineural invasion. IORT was administered as a single fraction of 15 or 20 Gy with 4-6-MeV electrons. The median follow-up period was 5.6 years. Results: Only 1 patient experienced local recurrence, 19 developed regional recurrence, and 12 distant recurrence. The recurrence-free survival rate at 1, 3, and 5 years was 82.0%, 68.5%, and 65.2%, respectively. The 1-, 3-, and 5-year overall survival rate after surgery and IORT was 88.4%, 66.1%, and 56.2%, respectively. No perioperative fatalities occurred. Complications developed in 26 patients and included vascular complications in 7, trismus in 6, fistulas in 4, radiation osteonecrosis in 4, flap necrosis in 2, wound dehiscence in 2, and neuropathy in 1. Of these 26 patients, 12 had recurrent disease, and 8 had undergone external beam radiotherapy before IORT. Conclusions: IORT results in effective local disease control at acceptable levels of toxicity and should be considered for patients with primary or recurrent cancer of the parotid gland.

  20. Fast neutron radiotherapy: For equal or for better

    SciTech Connect

    Broerse, J.J.; Battermann, J.J.

    1981-11-01

    The renewed application of fast neutrons in clinical radiotherapy has been stimulated by fundamental radiobiological findings. The biological effects of high LET radiation, including fast neutrons, are different from those obtained with x rays in at least three respects: the oxygen enhancement ratio, the sensitivity of cells at different phases of the cell cycle, and the contribution of sublethal damage to cell reproductive death. Furthermore, wide variations in relative biological effectiveness (RBE) have been observed for different tumors and normal tissues. Measurements of volume changes in human pulmonary metastases indicate that the RBE for slowly growing tumors which are generally well-differentiated is higher than that for poorly differentiated lesions. Six thousand patients have now been treated with fast neutron beams. The results of the clinical applications vary according to the method of application and to the type of cancer involved: treatment of inoperable malignancies of the salivary gland is very encouraging; the therapeutic gain is rather small for bladder and rectal cancers, soft tissue sarcomas and advanced carcinomas of the cervix; the responses of brain tumors are very disappointing. Most neutron radiotherapy applications have been less than optimal because of inadequate physical and technical conditions. Despite these difficulties, some interesting clinical data have become available. Due to the technical shortcomings, the possible advantages of fast neutrons are probably underestimated for many tumor sites. Well-designed clinical trials, preferably performed with high energy cyclotrons in clinical environments, will provide a decisive answer to the question of the usefulness of the new radiation modality. Key words: fast neutrons, radiotherapy, radiobiology

  1. [Quality & Safety in radiotherapy: advocacy for a professional strategy].

    PubMed

    Parmentier, G

    2008-11-01

    In medicine, as in oncological radiotherapy, as elsewhere, the precept of quality has no meaning if it is not defined. In France as everywhere radiotherapy has its forces and its weaknesses. As in every country, its future seems assured by its character cost effective as by its capacity to make progress in the triple point of view of its equipment, its professions and its organization. However, the French radiotherapy is in crisis. The professionals saw clearly. For more than 10 years they had recalled the medical authorities to their responsibilities concerning the demographic trends for the radiotherapists and the physicists, the renovation of the equipment, the modernization of the organizations, the promotion of the evaluation of procedures and outcomes and the development of a greater fairness in the financings. But the delay taken, the setting under pressure of the professionals by the State, its services, its agencies and the media following the recent accidents cause numerous perverse effects and worried the staff. The accident of Epinal was the starting fact of an effort of professionalisation of the risk management, but also of a disturbed period favourable with a certain confusion of minds, discouragement and protective behaviors. The risks felt by the professionals then seem especially to come from the authorities and the media. It appears that the topic of quality is at the center of all these speeches. Under this vocable, it is in fact the respect of the procedures related to the requirement of security which is privileged by the State and its representatives. The apparent security seems to override the real quality of the practices. Thus, time came for a clarification of the quality and security concepts, of organizations which contribute to it and for the development of a clear strategy bringing together the interprofessionnal actors. In this context, the implication of the College and especially of the Société française de radioth

  2. Exploiting tumor shrinkage through temporal optimization of radiotherapy

    NASA Astrophysics Data System (ADS)

    Unkelbach, Jan; Craft, David; Hong, Theodore; Papp, Dávid; Ramakrishnan, Jagdish; Salari, Ehsan; Wolfgang, John; Bortfeld, Thomas

    2014-06-01

    In multi-stage radiotherapy, a patient is treated in several stages separated by weeks or months. This regimen has been motivated mostly by radiobiological considerations, but also provides an approach to reduce normal tissue dose by exploiting tumor shrinkage. The paper considers the optimal design of multi-stage treatments, motivated by the clinical management of large liver tumors for which normal liver dose constraints prohibit the administration of an ablative radiation dose in a single treatment. We introduce a dynamic tumor model that incorporates three factors: radiation induced cell kill, tumor shrinkage, and tumor cell repopulation. The design of multi-stage radiotherapy is formulated as a mathematical optimization problem in which the total dose to the normal tissue is minimized, subject to delivering the prescribed dose to the tumor. Based on the model, we gain insight into the optimal administration of radiation over time, i.e. the optimal treatment gaps and dose levels. We analyze treatments consisting of two stages in detail. The analysis confirms the intuition that the second stage should be delivered just before the tumor size reaches a minimum and repopulation overcompensates shrinking. Furthermore, it was found that, for a large range of model parameters, approximately one-third of the dose should be delivered in the first stage. The projected benefit of multi-stage treatments in terms of normal tissue sparing depends on model assumptions. However, the model predicts large dose reductions by more than a factor of 2 for plausible model parameters. The analysis of the tumor model suggests that substantial reduction in normal tissue dose can be achieved by exploiting tumor shrinkage via an optimal design of multi-stage treatments. This suggests taking a fresh look at multi-stage radiotherapy for selected disease sites where substantial tumor regression translates into reduced target volumes.

  3. Ototoxicity after radiotherapy for head and neck tumors

    SciTech Connect

    Bhandare, Niranjan; Antonelli, Patrick J.; Morris, Christopher G.; Malayapa, Robert S.; Mendenhall, William M. . E-mail: mendewil@shands.ufl.edu

    2007-02-01

    Purpose: To investigate the incidence of radiation-induced ototoxicity according to the total dose delivered to specific parts of the auditory system, fractionation, and chemotherapy. Methods and Materials: Records of 325 patients treated for primary extracranial head and neck tumors with curative intent who received radiotherapy between 1964 and 2000 (median follow-up, 5.4 years) were retrospectively reviewed. Reconstructions of the treatment plans were generated to estimate the doses received by components of the auditory system. Results: Radiotherapy-induced morbidity developed in 41.8% of patients (external ear, 33.2%; middle ear, 28.6%; and inner ear, 26.8%). Univariate/multivariate analyses indicate that total dose received by parts of the auditory system seem to be significant, though fractionation and chemoradiation may contribute to the incidence of ototoxicities. Sensorineural hearing loss (SNHL) was observed in 49 patients (15.1%). Univariate and multivariate analyses indicated that age (p = 0.0177 and p = 0.005) and dose to cochlea (p < 0.0001 and p < 0.0001) were significant, and chemoradiation (p = 0.0281 and p = 0.006) may increase the incidence of SNHL. Five-year and 10-year actuarial risk of clinically overt SNHL increased to 37% (p > 0.0001) above doses of 60.5 Gy compared to 3% at doses below 60.5 Gy. For patients treated with adjuvant chemotherapy, clinically overt SNHL increased to 30% compared to 18% in the no-chemotherapy group at 10 years (p = 0.0281). Conclusion: Radiotherapy toxicity was observed in all parts of the auditory system with median doses for incidence varying between 60 Gy to 66 Gy. Total dose to organ seems to be a significant factor though fractionation and chemo-radiation may contribute to ototoxicities.

  4. Human Collagen Injections to Reduce Rectal Dose During Radiotherapy

    SciTech Connect

    Noyes, William R.; Hosford, Charles C.; Schultz, Steven E.

    2012-04-01

    Objectives: The continuing search for interventions, which address the incidence and grade of rectal toxicities associated with radiation treatment of prostate cancer, is a major concern. We are reporting an investigational trial using human collagen to increase the distance between the prostate and anterior rectal wall, thereby decreasing the radiation dose to the rectum. Methods: This is a pilot study evaluating the use of human collagen as a displacing agent for the rectal wall injected before starting a course of intensity-modulated radiotherapy (IMRT) for prostate cancer. Using a transperineal approach, 20 mL of human collagen was injected into the perirectal space in an outpatient setting. Computerized IMRT plans were performed pre- and postcollagen injection, and after a patient completed their radiotherapy, to determine radiation dose reduction to the rectum associated with the collagen injection. Computed tomography scans were performed 6 months and 12 months after completing their radiotherapy to evaluate absorption rate of the collagen. All patients were treated with IMRT to a dose of 75.6 Gy to the prostate. Results: Eleven patients were enrolled into the study. The injection of human collagen in the outpatient setting was well tolerated. The mean separation between the prostate and anterior rectum was 12.7 mm. The mean reduction in dose to the anterior rectal wall was 50%. All men denied any rectal symptoms during the study. Conclusions: The transperineal injection of human collagen for the purpose of tissue displacement is well tolerated in the outpatient setting. The increased separation between the prostate and rectum resulted in a significant decrease in radiation dose to the rectum while receiving IMRT and was associated with no rectal toxicities.

  5. [Quality & Safety in radiotherapy: advocacy for a professional strategy].

    PubMed

    Parmentier, G

    2008-11-01

    In medicine, as in oncological radiotherapy, as elsewhere, the precept of quality has no meaning if it is not defined. In France as everywhere radiotherapy has its forces and its weaknesses. As in every country, its future seems assured by its character cost effective as by its capacity to make progress in the triple point of view of its equipment, its professions and its organization. However, the French radiotherapy is in crisis. The professionals saw clearly. For more than 10 years they had recalled the medical authorities to their responsibilities concerning the demographic trends for the radiotherapists and the physicists, the renovation of the equipment, the modernization of the organizations, the promotion of the evaluation of procedures and outcomes and the development of a greater fairness in the financings. But the delay taken, the setting under pressure of the professionals by the State, its services, its agencies and the media following the recent accidents cause numerous perverse effects and worried the staff. The accident of Epinal was the starting fact of an effort of professionalisation of the risk management, but also of a disturbed period favourable with a certain confusion of minds, discouragement and protective behaviors. The risks felt by the professionals then seem especially to come from the authorities and the media. It appears that the topic of quality is at the center of all these speeches. Under this vocable, it is in fact the respect of the procedures related to the requirement of security which is privileged by the State and its representatives. The apparent security seems to override the real quality of the practices. Thus, time came for a clarification of the quality and security concepts, of organizations which contribute to it and for the development of a clear strategy bringing together the interprofessionnal actors. In this context, the implication of the College and especially of the Société française de radioth

  6. Biologically effective doses in radiotherapy of cervical carcinoma*.

    PubMed

    Urbanski, K; Gasinska, A; Pudelek, J; Fowler, J F; Lind, B; Brahme, A

    2004-01-01

    Presented study evaluates biologically effective dose (BED) in patients receiving low-medium dose-rate (LDR/MDR) brachytherapy (BRT) plus external beam radiotherapy (XRT) based on tumor cell proliferation values in cancer of the cervix patients. This study includes 229 patients treated entirely by radiotherapy at the Centre Oncology in Krakow. Doses to Point A were estimated for total treatment for each brachytherapy insertion. BED3 were calculated for reference points in the rectum. The linear quadratic equation was used to calculate BED, which is proportional to log cell kill, and the normalized total dose (NTD), that is, equivalent to a 2 Gy fraction schedule. In BEDs 10 calculation overall treatment time for each patient. Tumor proliferation rate was based on Bromodeoxyuridine labeling index (BrdUrdLI) assessed on biopsy material before beginning the radiotherapy. Total BED at those points was summed for each patient. The medium overall treatment time was 90 days (range 30--210). The mean calculated total BED for point A for tumour and "early reactions" was equal to 104.0 Gy10 and 229.0 Gy3 for the rectum, equivalent to NTD=86.6 Gy and 137.4 Gy in 2 Gy fractions, respectively. Kaplan-Meier analysis revealed that age >50 years, higher than mean BRBEDs and totBEDs doses, gaps in treatments shorter than 40 days and disease free survival (DFS) was significant prognostic factor for overall survival. In the multivariate Cox anaysis age >50 years, BRBED10 >77 Gy and gaps ?40 days appeared to be significant for overall survival. None of the examined parameters was significant for tumor control. However, patientś age and shorter gaps in the treatment were predictive for DFS. PMID:15254678

  7. Spatio-Temporal Dynamics of Hypoxia during Radiotherapy

    PubMed Central

    Kempf, Harald; Bleicher, Marcus; Meyer-Hermann, Michael

    2015-01-01

    Tumour hypoxia plays a pivotal role in cancer therapy for most therapeutic approaches from radiotherapy to immunotherapy. The detailed and accurate knowledge of the oxygen distribution in a tumour is necessary in order to determine the right treatment strategy. Still, due to the limited spatial and temporal resolution of imaging methods as well as lacking fundamental understanding of internal oxygenation dynamics in tumours, the precise oxygen distribution map is rarely available for treatment planing. We employ an agent-based in silico tumour spheroid model in order to study the complex, localized and fast oxygen dynamics in tumour micro-regions which are induced by radiotherapy. A lattice-free, 3D, agent-based approach for cell representation is coupled with a high-resolution diffusion solver that includes a tissue density-dependent diffusion coefficient. This allows us to assess the space- and time-resolved reoxygenation response of a small subvolume of tumour tissue in response to radiotherapy. In response to irradiation the tumour nodule exhibits characteristic reoxygenation and re-depletion dynamics which we resolve with high spatio-temporal resolution. The reoxygenation follows specific timings, which should be respected in treatment in order to maximise the use of the oxygen enhancement effects. Oxygen dynamics within the tumour create windows of opportunity for the use of adjuvant chemotherapeutica and hypoxia-activated drugs. Overall, we show that by using modelling it is possible to follow the oxygenation dynamics beyond common resolution limits and predict beneficial strategies for therapy and in vitro verification. Models of cell cycle and oxygen dynamics in tumours should in the future be combined with imaging techniques, to allow for a systematic experimental study of possible improved schedules and to ultimately extend the reach of oxygenation monitoring available in clinical treatment. PMID:26273841

  8. Low-cost commercial glass beads as dosimeters in radiotherapy

    NASA Astrophysics Data System (ADS)

    Jafari, S. M.; Bradley, D. A.; Gouldstone, C. A.; Sharpe, P. H. G.; Alalawi, A.; Jordan, T. J.; Clark, C. H.; Nisbet, A.; Spyrou, N. M.

    2014-04-01

    Recent developments in advanced radiotherapy techniques using small field photon beams, require small detectors to determine the delivered dose in steep dose gradient fields. Commercially available glass jewellery beads exhibit thermoluminescent properties and have the potential to be used as dosimeters in radiotherapy due to their small size (<5 mm), low cost, reusability and inert nature. This study investigated the dosimetric characteristics of glass beads. The beads were irradiated by 6 MV photons using a medical linear-accelerator and 60Co gamma rays over doses ranging from 1 to 2500 cGy. A thermoluminescence (TL) system and an electron paramagnetic resonance (EPR) system were employed for read out. Both the TL and EPR studies demonstrated a radiation-induced signal, the sensitivity of which varied with bead colour. White coloured beads proved to be the most sensitive for both systems. The smallest and therefore least sensitive bead sizes allowed measurement of doses of 1 cGy using the TL system while that for the EPR system was approximately 1000 cGy. The fading rate was found to be 10% 30 days after irradiation with both readout systems. The dose response is linear with measured dose over the dose range 1 to 2500 cGy, with an R2 correlation coefficient of greater than 0.999. The batch-to-batch reproducibility of a set of dosimeters after a single irradiation was found to be 3% (1 SD). The reproducibility of individual dosimeters was found to be 1.7%. No measurable angular dependence was found (results agreed within 1%). Dose rate response was found to agree within 1% for dose rates of 100 to 600 cGy/min. These results demonstrate the potential use of glass beads as TL dosimeters over the dose range commonly applied in radiotherapy.

  9. Navigated marker placement for motion compensation in radiotherapy

    NASA Astrophysics Data System (ADS)

    Winterstein, A.; März, K.; Franz, A. M.; Hafezi, M.; Fard, N.; Sterzing, F.; Mehrabi, A.; Maier-Hein, L.

    2015-03-01

    Radiotherapy is frequently used to treat unoperated or partially resected tumors. Tumor movement, e.g. caused by respiration, is a major challenge in this context. Markers can be implanted around the tumor prior to radiation therapy for accurate tracking of tumor movement. However, accurate placement of these markers while keeping a secure margin around the target and while taking into account critical structures is a difficult task. Computer-assisted needle insertion has been an active field of research in the past decades. However, the challenge of navigated marker placement for motion compensated radiotherapy has not yet been addressed. This work presents a system to support marker implantation for radiotherapy under consideration of safety margins and optimal marker configuration. It is designed to allow placement of markers both percutaneously and during an open liver surgery. To this end, we adapted the previously proposed EchoTrack system which integrates ultrasound (US) imaging and electromagnetic (EM) tracking in a single mobile modality. The potential of our new marker insertion concept was evaluated in a phantom study by inserting sets of three markers around dedicated targets (n=22) simultaneously spacing the markers evenly around the target as well as placing the markers in a defined distance to the target. In all cases the markers were successfully placed in a configuration fulfilling the predefined criteria. This includes a minimum distance of 18.9 ± 2.4 mm between marker and tumor as well as a divergence of 2.1 ± 1.5 mm from the planned marker positions. We conclude that our system has high potential to facilitate the placement of markers in suitable configurations for surgeons without extensive experience in needle punctions as high quality configurations were obtained even by medical non-experts.

  10. [Feasibility of Automatic Treatment Planning in Intensity-modulated Radiotherapy of Nasopharyngeal Carcinoma].

    PubMed

    He, Yinbo; Zhang, Longbin; Xiao, Jianghong; Duan, Baofeng

    2015-12-01

    Intensity-modulated radiotherapy planning for nasopharyngeal carcinoma is very complex. The quality of plan is often closely linked to the experience of the treatment planner. In this study, 10 nasopharyngeal carcinoma patients at different stages were enrolled. Based on the scripting of Pinnacle 9. 2 treatment planning system, the computer program was used to set the basic parameters and objective parameters of the plans. At last, the nasopharyngeal carcinoma intensity-modulated radiotherapy plans were completed automatically. Then, the automatical and manual intensity-modulated radiotherapy plans were statistically compared and clinically evaluated. The results showed that there were no significant differences between those two kinds of plans with respect to the dosimetry parameters of most targets and organs at risk. The automatical nasopharyngeal carcinoma intensity-modulated radiotherapy plans can meet the requirements of clinical radiotherapy, significantly reduce planning time, and avoid the influence of human factors such as lack of experience to the quality of plan. PMID:27079103

  11. The first Rs of radiotherapy: or standing on the shoulders of giants.

    PubMed

    Marcu, Loredana G

    2015-12-01

    The name of the Australian-born professor, Rodney H. Withers, is highly acknowledged among radiation biologists, radiation oncologists, medical physicists and other professionals. The list of his contributions towards knowledge enhancement and better understanding of the biological basis for radiotherapy is a long one. However, there are certain landmarks of Dr. Withers’ research that are worth emphasizing, as they have marked several paths along the development of radiotherapy: the four Rs of radiotherapy, the accelerated tumour growth during treatment, the time-factor in radiotherapy, altered fractionation schemes and their corresponding isoeffect curves, normal tissue tolerance and organ architecture—just to name a few. This paper is a tribute to the work of Rodney Withers, which, far from being exhaustive, marks some of his greatest contributions to radiotherapy.

  12. Development of Advanced Multi-Modality Radiation Treatment Planning Software for Neutron Radiotherapy and Beyond

    SciTech Connect

    Nigg, D; Wessol, D; Wemple, C; Harkin, G; Hartmann-Siantar, C

    2002-08-20

    The Idaho National Engineering and Environmental Laboratory (INEEL) has long been active in development of advanced Monte-Carlo based computational dosimetry and treatment planning methods and software for advanced radiotherapy, with a particular focus on Neutron Capture Therapy (NCT) and, to a somewhat lesser extent, Fast-Neutron Therapy. The most recent INEEL software system of this type is known as SERA, Simulation Environment for Radiotherapy Applications. As a logical next step in the development of modern radiotherapy planning tools to support the most advanced research, INEEL and Lawrence Livermore National Laboratory (LLNL), the developers of the PEREGRTNE computational engine for radiotherapy treatment planning applications, have recently launched a new project to collaborate in the development of a ''next-generation'' multi-modality treatment planning software system that will be useful for all modern forms of radiotherapy.

  13. Visualization of complex DNA double-strand breaks in a tumor treated with carbon ion radiotherapy

    PubMed Central

    Oike, Takahiro; Niimi, Atsuko; Okonogi, Noriyuki; Murata, Kazutoshi; Matsumura, Akihiko; Noda, Shin-Ei; Kobayashi, Daijiro; Iwanaga, Mototaro; Tsuchida, Keisuke; Kanai, Tatsuaki; Ohno, Tatsuya; Shibata, Atsushi; Nakano, Takashi

    2016-01-01

    Carbon ion radiotherapy shows great potential as a cure for X-ray-resistant tumors. Basic research suggests that the strong cell-killing effect induced by carbon ions is based on their ability to cause complex DNA double-strand breaks (DSBs). However, evidence supporting the formation of complex DSBs in actual patients is lacking. Here, we used advanced high-resolution microscopy with deconvolution to show that complex DSBs are formed in a human tumor clinically treated with carbon ion radiotherapy, but not in a tumor treated with X-ray radiotherapy. Furthermore, analysis using a physics model suggested that the complexity of radiotherapy-induced DSBs is related to linear energy transfer, which is much higher for carbon ion beams than for X-rays. Visualization of complex DSBs in clinical specimens will help us to understand the anti-tumor effects of carbon ion radiotherapy. PMID:26925533

  14. [Definition of accurate planning target volume margins for esophageal cancer radiotherapy].

    PubMed

    Lesueur, P; Servagi-Vernat, S

    2016-10-01

    More than 4000 cases of esophagus neoplasms are diagnosed every year in France. Radiotherapy, which can be delivered in preoperative or exclusive with a concomitant chemotherapy, plays a central role in treatment of esophagus cancer. Even if efficacy of radiotherapy no longer has to be proved, the prognosis of esophagus cancer remains unfortunately poor with a high recurrence rate. Toxicity of esophageal radiotherapy is correlated with the irradiation volume, and limits dose escalation and local control. Esophagus is a deep thoracic organ, which undergoes cardiac and respiratory motion, making the radiotherapy delivery more difficult and increasing the planning target volume margins. Definition of accurate planning target volume margins, taking into account the esophagus' intrafraction motion and set up margins is very important to be sure to cover the clinical target volume and restrains acute and late radiotoxicity. In this article, based on a review of the literature, we propose planning target volume margins adapted to esophageal radiotherapy.

  15. Measuring neutron spectra in radiotherapy using the nested neutron spectrometer

    SciTech Connect

    Maglieri, Robert Evans, Michael; Seuntjens, Jan; Kildea, John; Licea, Angel

    2015-11-15

    Purpose: Out-of-field neutron doses resulting from photonuclear interactions in the head of a linear accelerator pose an iatrogenic risk to patients and an occupational risk to personnel during radiotherapy. To quantify neutron production, in-room measurements have traditionally been carried out using Bonner sphere systems (BSS) with activation foils and TLDs. In this work, a recently developed active detector, the nested neutron spectrometer (NNS), was tested in radiotherapy bunkers. Methods: The NNS is designed for easy handling and is more practical than the traditional BSS. Operated in current-mode, the problem of pulse pileup due to high dose-rates is overcome by measuring current, similar to an ionization chamber. In a bunker housing a Varian Clinac 21EX, the performance of the NNS was evaluated in terms of reproducibility, linearity, and dose-rate effects. Using a custom maximum-likelihood expectation–maximization algorithm, measured neutron spectra at various locations inside the bunker were then compared to Monte Carlo simulations of an identical setup. In terms of dose, neutron ambient dose equivalents were calculated from the measured spectra and compared to bubble detector neutron dose equivalent measurements. Results: The NNS-measured spectra for neutrons at various locations in a treatment room were found to be consistent with expectations for both relative shape and absolute magnitude. Neutron fluence-rate decreased with distance from the source and the shape of the spectrum changed from a dominant fast neutron peak near the Linac head to a dominant thermal neutron peak in the moderating conditions of the maze. Monte Carlo data and NNS-measured spectra agreed within 30% at all locations except in the maze where the deviation was a maximum of 40%. Neutron ambient dose equivalents calculated from the authors’ measured spectra were consistent (one standard deviation) with bubble detector measurements in the treatment room. Conclusions: The NNS may

  16. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    SciTech Connect

    Venhuizen, James R.

    2002-04-30

    This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.

  17. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    SciTech Connect

    Venhuizen, James Robert

    2002-04-01

    This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.

  18. Radiotherapy for Liver Metastases: A Review of Evidence

    SciTech Connect

    Hoyer, Morten; Swaminath, Anand; Bydder, Sean; Lock, Michael; Mendez Romero, Alejandra; Kavanagh, Brian; Goodman, Karyn A.; Okunieff, Paul; Dawson, Laura A.

    2012-03-01

    Over the past decade, there has been an increasing use of radiotherapy (RT) for the treatment of liver metastases. Most often, ablative doses are delivered to focal liver metastases with the goal of local control and ultimately improving survival. In contrast, low-dose whole-liver RT may be used for the palliation of symptomatic diffuse metastases. This review examines the available clinical data for both approaches. The review found that RT is effective both for local ablation of focal liver metastases and for palliation of patients with symptomatic liver metastases. However, there is a lack of a high level of evidence from randomized clinical trials.

  19. The prevention and treatment of radiotherapy - induced xerostomia.

    PubMed

    Eisbruch, Avraham; Rhodus, Nelson; Rosenthal, David; Murphy, Barbara; Rasch, Coen; Sonis, Stephen; Scarantino, Charles; Brizel, David

    2003-07-01

    Efforts to reduce the severity of postradiotherapy xerostomia include the use of salivary substitutes to gain symptomatic relief, salivary gland stimulants, agents delivered to protect the glands during radiotherapy (RT), and physical means to partially spare the major salivary glands from RT while adequately irradiating tumor targets. These means include advanced RT treatment planning and salivary tissue transfer to nonirradiated areas. The relative potential gain from each of these strategies is discussed in this article. The combination of partial salivary gland sparing and radiation protectors/stimulants may provide additive or synergistic gains in reducing the severity of xerostomia. PMID:12903018

  20. Assessing the risk of second malignancies after modern radiotherapy

    PubMed Central

    Newhauser, Wayne D.; Durante, Marco

    2014-01-01

    Recent advances in radiotherapy have enabled the use of different types of particles, such as protons and heavy ions, as well as refinements to the treatment of tumours with standard sources (photons). However, the risk of second cancers arising in long-term survivors continues to be a problem. The long-term risks from treatments such as particle therapy have not yet been determined and are unlikely to become apparent for many years. Therefore, there is a need to develop risk assessments based on our current knowledge of radiation-induced carcinogenesis. PMID:21593785

  1. A set of fortran subroutines for optimizing radiotherapy plans.

    PubMed

    Redpath, A T; Vickery, B L; Wright, D H

    1975-12-01

    Quadratic Programming techniques have been applied to the optimization of radiation field weighting in Radiotherapy planning. Wedge selection has also been included by means of an exhaustive search. The radiation dose at any point in the patient may be constrained to be less than a stated percentage of the tumour dose. The routines have been successfully interfaced into a small computer interactive planning system, but they could represent an even more powerful tool in batch and time sharing systems. Minimum operator intervention is required in their use.

  2. Assessment of Extended-Field Radiotherapy for Stage IIIC Endometrial Cancer Using Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, and Helical Tomotherapy

    SciTech Connect

    Lian Jidong Mackenzie, Marc; Joseph, Kurian; Pervez, Nadeem; Dundas, George; Urtasun, Raul; Pearcey, Robert

    2008-03-01

    Purpose: To perform a dosimetric comparison of three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and helical tomotherapy (HT) plans for pelvic and para-aortic RT in postoperative endometrial cancer patients; and to evaluate the integral dose (ID) received by critical structures within the radiation fields. Methods and Materials: We selected 10 patients with Stage IIIC endometrial cancer. For each patient, three plans were created with 3D-CRT, IMRT, and HT. The IMRT and HT plans were both optimized to keep the mean dose to the planning target volume (PTV) the same as that with 3D-CRT. The dosimetry and ID for the critical structures were compared. A paired two-tailed Student t test was used for data analysis. Results: Compared with the 3D-CRT plans, the IMRT plans resulted in lower IDs in the organs at risk (OARs), ranging from -3.49% to -17.59%. The HT plans showed a similar result except that the ID for the bowel increased 0.27%. The IMRT and HT plans both increased the IDs to normal tissue (see and text for definition), pelvic bone, and spine (range, 3.31-19.7%). The IMRT and HT dosimetry showed superior PTV coverage and better OAR sparing than the 3D-CRT dosimetry. Compared directly with IMRT, HT showed similar PTV coverage, lower Ids, and a decreased dose to most OARs. Conclusion: Intensity-modulated RT and HT appear to achieve excellent PTV coverage and better sparing of OARs, but at the expense of increased IDs to normal tissue and skeleton. HT allows for additional improvement in dosimetry and sparing of most OARs.

  3. Radiotherapy for Esthesioneuroblastoma: Is Elective Nodal Irradiation Warranted in the Multimodality Treatment Approach?

    SciTech Connect

    Noh, O Kyu; Lee, Sang-wook; Yoon, Sang Min; Kim, Sung Bae; Kim, Sang Yoon; Kim, Chang Jin; Jo, Kyung Ja; Choi, Eun Kyung; Song, Si Yeol; Kim, Jong Hoon; Ahn, Seung Do

    2011-02-01

    Purpose: The role of elective nodal irradiation (ENI) in radiotherapy for esthesioneuroblastoma (ENB) has not been clearly defined. We analyzed treatment outcomes of patients with ENB and the frequency of cervical nodal failure in the absence of ENI. Methods and Materials: Between August 1996 and December 2007, we consulted with 19 patients with ENB regarding radiotherapy. Initial treatment consisted of surgery alone in 2 patients; surgery and postoperative radiotherapy in 4; surgery and adjuvant chemotherapy in 1; surgery, postoperative radiotherapy, and chemotherapy in 3; and chemotherapy followed by radiotherapy or concurrent chemoradiotherapy in 5. Five patients did not receive planned radiotherapy because of disease progression. Including 2 patients who received salvage radiotherapy, 14 patients were treated with radiotherapy. Elective nodal irradiation was performed in 4 patients with high-risk factors, including 3 with cervical lymph node metastasis at presentation. Results: Fourteen patients were analyzable, with a median follow-up of 27 months (range, 7-64 months). The overall 3-year survival rate was 73.4%. Local failure occurred in 3 patients (21.4%), regional cervical failure in 3 (21.4%), and distant failure in 2 (14.3%). No cervical nodal failure occurred in patients treated with combined systemic chemotherapy regardless of ENI. Three cervical failures occurred in the 4 patients treated with ENI or neck dissection (75%), none of whom received systemic chemotherapy. Conclusions: ENI during radiotherapy for ENB seems to play a limited role in preventing cervical nodal failure. Omitting ENI may be an option if patients are treated with a combination of radiotherapy and chemotherapy.

  4. Baseline Utilization of Breast Radiotherapy Before Institution of the Medicare Practice Quality Reporting Initiative

    SciTech Connect

    Smith, Benjamin D. Smith, Grace L.; Roberts, Kenneth B.; Buchholz, Thomas A.

    2009-08-01

    Purpose: In 2007, Medicare implemented the Physician Quality Reporting Initiative (PQRI), which provides financial incentives to physicians who report their performance on certain quality measures. PQRI measure no. 74 recommends radiotherapy for patients treated with conservative surgery (CS) for invasive breast cancer. As a first step in evaluating the potential impact of this measure, we assessed baseline use of radiotherapy among women diagnosed with invasive breast cancer before implementation of PQRI. Methods and Materials: Using the SEER-Medicare data set, we identified women aged 66-70 diagnosed with invasive breast cancer and treated with CS between 2000 and 2002. Treatment with radiotherapy was determined using SEER and claims data. Multivariate logistic regression tested whether receipt of radiotherapy varied significantly across clinical, pathologic, and treatment covariates. Results: Of 3,674 patients, 94% (3,445) received radiotherapy. In adjusted analysis, the presence of comorbid illness (odds ratio [OR] 1.69; 95% confidence interval [CI], 1.19-2.42) and unmarried marital status were associated with omission of radiotherapy (OR 1.65; 95% CI, 1.22-2.20). In contrast, receipt of chemotherapy was protective against omission of radiotherapy (OR 0.25; 95% CI, 0.16-0.38). Race and geographic region did not correlate with radiotherapy utilization. Conclusions: Utilization of radiotherapy following CS was high for patients treated before institution of PQRI, suggesting that at most 6% of patients could benefit from measure no. 74. Further research is needed to determine whether institution of PQRI will affect radiotherapy utilization.

  5. Dosimetric comparison of carbon ion and X-ray radiotherapy for Stage IIIA non–small cell lung cancer

    PubMed Central

    Kubo, Nobuteru; Saitoh, Jun-ichi; Shimada, Hirofumi; Shirai, Katsuyuki; Kawamura, Hidemasa; Ohno, Tatsuya; Nakano, Takashi

    2016-01-01

    The present study compared the dose–volume histograms of patients with Stage IIIA non–small cell lung cancer (NSCLC) treated with carbon ion radiotherapy with those of patients treated with X-ray radiotherapy. Patients with Stage IIIA NSCLC (n = 10 patients for each approach) were enrolled. Both radiotherapy plans were calculated with the same targets and organs at risk on the same CT. The treatment plan for the prophylactic lymph node and primary tumor (PTV1) delivered 40 Gy for X-ray radiotherapy and 40 Gy (relative biological effectiveness; RBE) for carbon ion radiotherapy. The total doses for the primary tumor and clinically positive lymph nodes (PTV2) were 60 Gy for X-ray radiotherapy and 60 Gy (RBE) for carbon ion radiotherapy. The homogeneity indexes for PTV1 and PTV2 were superior for carbon ion radiotherapy in comparison with X-ray radiotherapy (PTV1, 0.57 vs 0.65, P = 0.009; PTV2, 0.07 vs 0.16, P = 0.005). The normal lung mean dose, V5, V10 and V20 for carbon ion radiotherapy were 7.7 Gy (RBE), 21.4%, 19.7% and 17.0%, respectively, whereas the corresponding doses for X-ray radiotherapy were 11.9 Gy, 34.9%, 26.6% and 20.8%, respectively. Maximum spinal cord dose, esophageal maximum dose and V50, and bone V10, V30 and V50 were lower with carbon ion radiotherapy than with X-ray radiotherapy. The present study indicates that carbon ion radiotherapy provides a more homogeneous target dose and a lower dose to organs at risk than X-ray radiotherapy for Stage IIIA non–small cell lung cancer. PMID:27242341

  6. Image-Guided Radiotherapy via Daily Online Cone-Beam CT Substantially Reduces Margin Requirements for Stereotactic Lung Radiotherapy

    SciTech Connect

    Grills, Inga S. Hugo, Geoffrey; Kestin, Larry L.; Galerani, Ana Paula; Chao, K. Kenneth; Wloch, Jennifer; Yan Di

    2008-03-15

    Purpose: To determine treatment accuracy and margins for stereotactic lung radiotherapy with and without cone-beam CT (CBCT) image guidance. Methods and Materials: Acquired for the study were 308 CBCT of 24 patients with solitary peripheral lung tumors treated with stereotactic radiotherapy. Patients were immobilized in a stereotactic body frame (SBF) or alpha-cradle and treated with image guidance using daily CBCT. Four (T1) or five (T2/metastatic) 12-Gy fractions were prescribed to the planning target volume (PTV) edge. The PTV margin was {>=}5 mm depending on a pretreatment estimate of tumor excursion. Initial daily setup was according to SBF coordinates or tattoos for alpha-cradle cases. A CBCT was performed and registered to the planning CT using soft tissue registration of the target. The initial setup error/precorrection position, was recorded for the superior-inferior, anterior-posterior, and medial-lateral directions. The couch was adjusted to correct the tumor positional error. A second CBCT verified tumor position after correction. Patients were treated in the corrected position after the residual errors were {<=}2 mm. A final CBCT after treatment assessed intrafraction tumor displacement. Results: The precorrection systematic ({sigma}) and random errors ({sigma}) for the population ranged from 2-3 mm for SBF and 2-6 mm for alpha-cradle patients; postcorrection errors ranged from 0.4-1.0 mm. Calculated population margins were 9 to 13 mm (SBF) and 10-14 mm (cradle) precorrection, 1-2 mm (SBF), and 2-3 mm (cradle) postcorrection, and 2-4 mm (SBF) and 2-5 mm (cradle) posttreatment. Conclusions: Setup for stereotactic lung radiotherapy using a SBF or alpha-cradle alone is suboptimal. CBCT image guidance significantly improves target positioning and substantially reduces required target margins and normal tissue irradiation.

  7. Tracked regularized ultrasound elastography for targeting breast radiotherapy.

    PubMed

    Rivaz, Hassan; Foroughi, Pezhman; Fleming, Ioana; Zellars, Richard; Boctor, Emad; Hager, Gregory

    2009-01-01

    Tracked ultrasound elastography can be used for guidance in partial breast radiotherapy by visualizing the hard scar tissue around the lumpectomy cavity. For clinical success, the elastography method needs to be robust to the sources of decorrelation between ultrasound images, specifically fluid motions inside the cavity, change of the appearance of speckles caused by compression or physiologic motions, and out-of-plane motion of the probe. In this paper, we present a novel elastography technique that is based on analytic minimization of a regularized cost function. The cost function incorporates similarity of RF data intensity and displacement continuity, making the method robust to small decorrelations present throughout the image. We also exploit techniques from robust statistics to make the method resistant to large decorrelations caused by sources such as fluid motion. The analytic displacement estimation works in real-time. Moreover, the tracked data, used for targeting the radiotherapy, is exploited for discarding frames with excessive out-of-plane motion. Simulation, phantom and patient results are presented.

  8. Hypofractionated ablative radiotherapy for locally advanced pancreatic cancer.

    PubMed

    Crane, Christopher H

    2016-08-01

    The role of radiation in locally advanced unresectable pancreatic cancer (LAPC) is controversial. Randomized trials evaluating standard doses of chemoradiation have not shown a significant benefit from the use of consolidative radiation. Results from non-randomized studies of 3-5-fraction stereotactic body radiotherapy (SBRT) have been similar to standard chemoradiation, but with less toxicity and a shorter treatment time. Doses of SBRT have been reduced to subablative levels for the sake of tolerability. The benefit of both options is unclear. In contrast, ablative doses can be delivered using an SBRT technique in 15-28 fractions. The keys to the delivery of ablative doses are computed tomography (CT) image guidance and respiratory gating. Higher doses have resulted in encouraging long-term survival results. In this review, we present a comprehensive solution to achieving ablative doses for selected patients with pancreatic tumors by using a combination of classical, modern and novel concepts of radiotherapy: fractionation, CT image guidance, respiratory gating, intentional dose heterogeneity, and simultaneous integrated protection.

  9. Radiotherapy induced hip joint avascular necrosis—Two cases report

    PubMed Central

    Michalecki, Łukasz; Gabryś, Dorota; Kulik, Roland; Wydmański, Jerzy; Trela, Krystyna

    2011-01-01

    Background Avascular necrosis (AVN) refers to the death of osteocytes and osteoblasts. Sites such as the femoral head, the head of the humerus and the mandibula with restricted access to local blood supply are particularly vulnerable to osteonecrosis. A combination of several factors is responsible for ischaemia and is associated with AVN: corticosteroids, alcohol abuse, Cushing's syndrome, SLE, systemic vasculitis, RA, scleroderma, haemoglobinopathies, radiotherapy. Management is based on proper diagnosis and treatment – conservative, pharmacological or surgical. Radiotherapy has become an integral part of the therapeutic programme of cancer patients. However, early and late after-effects of irradiation still constitute a significant issue in clinical practice. Aim The aim of this report is to present two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic irradiation and draw physicians’ attention to that clinical problem which continues to be underestimated. Materials and methods This report documents two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic radiation. Results Avascular necrosis (AVN) constitutes a severe and challenging long-term complication in radiation oncology. Conclusion It is necessary to take into account bone structures among organ at risk (OAR) involved in irradiation fields. The detailed analysis of the dose distribution and the use of collimators allow to decrease the total dose to OAR. An adequate management, early diagnosis and prompt, proper treatment may protect patients from long-term morbidities. PMID:24376980

  10. In vivo skin dose measurement in breast conformal radiotherapy

    PubMed Central

    Soleymanifard, Shokouhozaman; Noghreiyan, Atefeh Vejdani; Ghorbani, Mahdi; Jamali, Farideh; Davenport, David

    2016-01-01

    Aim of the study Accurate skin dose assessment is necessary during breast radiotherapy to assure that the skin dose is below the tolerance level and is sufficient to prevent tumour recurrence. The aim of the current study is to measure the skin dose and to evaluate the geometrical/anatomical parameters that affect it. Material and methods Forty patients were simulated by TIGRT treatment planning system and treated with two tangential fields of 6 MV photon beam. Wedge filters were used to homogenise dose distribution for 11 patients. Skin dose was measured by thermoluminescent dosimeters (TLD-100) and the effects of beam incident angle, thickness of irradiated region, and beam entry separation on the skin dose were analysed. Results Average skin dose in treatment course of 50 Gy to the clinical target volume (CTV) was 36.65 Gy. The corresponding dose values for patients who were treated with and without wedge filter were 35.65 and 37.20 Gy, respectively. It was determined that the beam angle affected the average skin dose while the thickness of the irradiated region and the beam entry separation did not affect dose. Since the skin dose measured in this study was lower than the amount required to prevent tumour recurrence, application of bolus material in part of the treatment course is suggested for post-mastectomy advanced breast radiotherapy. It is more important when wedge filters are applied to homogenize dose distribution. PMID:27358592

  11. Hypofractionated ablative radiotherapy for locally advanced pancreatic cancer

    PubMed Central

    Crane, Christopher H.

    2016-01-01

    The role of radiation in locally advanced unresectable pancreatic cancer (LAPC) is controversial. Randomized trials evaluating standard doses of chemoradiation have not shown a significant benefit from the use of consolidative radiation. Results from non-randomized studies of 3–5-fraction stereotactic body radiotherapy (SBRT) have been similar to standard chemoradiation, but with less toxicity and a shorter treatment time. Doses of SBRT have been reduced to subablative levels for the sake of tolerability. The benefit of both options is unclear. In contrast, ablative doses can be delivered using an SBRT technique in 15–28 fractions. The keys to the delivery of ablative doses are computed tomography (CT) image guidance and respiratory gating. Higher doses have resulted in encouraging long-term survival results. In this review, we present a comprehensive solution to achieving ablative doses for selected patients with pancreatic tumors by using a combination of classical, modern and novel concepts of radiotherapy: fractionation, CT image guidance, respiratory gating, intentional dose heterogeneity, and simultaneous integrated protection. PMID:27029741

  12. The current status of targeted radiotherapy in clinical practice.

    PubMed

    Gaze, M N

    1996-10-01

    Biologically targeted radiotherapy in clinical practice requires a molecule which has a relative specificity for tumour tissue--the missile--coupled to a radionuclide with appropriate physical characteristics--the warhead. When administered to a patient this combination should result in selective irradiation of the target tumour cells with relative sparing of normal tissues. Simple ions and small molecules which follow physiological pathways as either the natural substrates or analogues form the best examples of biological targeting. Clinically valuable results are seen with, for instance, iodine uptake by normal and malignant thyroid cells, incorporation of the calci-mimetic element strontium in areas of increased bone metabolism and accumulation of the catecholamine analogue meta-iodobenzylguanidine in neuroblastoma. The use of monoclonal antibodies as targeting vehicles has not proved to be a panacea, yet some patients with lymphoma, hepatoma and ovarian carcinoma have obtained benefit. Current clinical studies in targeted radiotherapy focus on the integration of radionuclide treatment with conventional treatments, and the optimization of such combined approaches. The development of modifications to offset the limitations inherent in the use of crude antibodies also offers an opportunity for improved clinical outcomes.

  13. Alternating chemo-radiotherapy in bladder cancer: A conservative approach

    SciTech Connect

    Orsatti, M.; Franzone, P.; Giudici, S.

    1995-08-30

    The aim of this Phase II study was to determine a bladder-sparing treatment in patients with invasive bladder cancer, allowing a better quality of life. Objectives were to test toxicity and disease-free and overall survival of patients given an alternated chemo-radiotherapy definitive treatment. Seventy-six patients with bladder cancer Stage T1G3 through T4 N0 M0 were entered in the same chemotherapy regimen (Cisplatin 20 mg/mq and 5-Fluorouracil 200 mg/mq daily for 5 days) alternated with different radiotherapy scheduling, the first 18 patients received two cycles of 20 Gy/10 fractions/12 days each; the second group of 58 patients received two cycles of 25 Gy/10 fractions/12 days each (the last 21 patients received Methotrexate 40 mg/mq instead of 5-Fluorouracil). A clinical complete response was observed in 57 patients (81%), partial response in 7 patients (10%), and a nonresponse in 6 patients (9%). At a median follow-up of 45 months, 33 patients (47%) were alive and free of tumor. The 6-year overall survival and progression-free survival was 42% and 40%, respectively. Systemic side effects were mild, while a moderate or severe local toxicity was observed in 14 patients and 13 patients (about 20%), respectively. Our conservative combination treatment allowed bladder-sparing in a high rate of patients and resulted in a survival comparable to that reported after radical cystectomy. 34 refs., 4 figs., 5 tabs.

  14. Fractionated Proton Radiotherapy for Benign Cavernous Sinus Meningiomas

    SciTech Connect

    Slater, Jerry D.; Loredo, Lilia N.; Chung, Arthur; Bush, David A.; Patyal, Baldev; Johnson, Walter D.; Hsu, Frank P.K.; Slater, James M.

    2012-08-01

    Purpose: To evaluate the efficacy of fractionated proton radiotherapy for a population of patients with benign cavernous sinus meningiomas. Methods and Materials: Between 1991 and 2002, 72 patients were treated at Loma Linda University Medical Center with proton therapy for cavernous sinus meningiomas. Fifty-one patients had biopsy or subtotal resection; 47 had World Health Organization grade 1 pathology. Twenty-one patients had no histologic verification. Twenty-two patients received primary proton therapy; 30 had 1 previous surgery; 20 had more than 1 surgery. The mean gross tumor volume was 27.6 cm{sup 3}; mean clinical target volume was 52.9 cm{sup 3}. Median total doses for patients with and without histologic verification were 59 and 57 Gy, respectively. Mean and median follow-up periods were 74 months. Results: The overall 5-year actuarial control rate was 96%; the control rate was 99% in patients with grade 1 or absent histologic findings and 50% for those with atypical histology. All 21 patients who did not have histologic verification and 46 of 47 patients with histologic confirmation of grade 1 tumor demonstrated disease control at 5 years. Control rates for patients without previous surgery, 1 surgery, and 2 or more surgeries were 95%, 96%, and 95%, respectively. Conclusions: Fractionated proton radiotherapy for grade 1 cavernous sinus meningiomas achieves excellent control rates with minimal toxicities, regardless of surgical intervention or use of histologic diagnosis. Disease control for large lesions can be achieved by primary fractionated proton therapy.

  15. How to Improve Therapeutic Ratio in Radiotherapy of HCC

    PubMed Central

    Tsai, Chiao-Ling; Hsu, Feng-Ming; Cheng, Jason Chia-Hsien

    2016-01-01

    Background During the past two decades, external-beam radiation technology has substantially changed from traditional two-dimensional to conformal three-dimensional to intensity-modulated planning and stereotactic body radiotherapy (SBRT). Summary Modern techniques of radiotherapy (RT) are highly focused and capable of delivering an ablative dose to targeted hepatocellular carcinoma (HCC) tumors. SBRT is an option for selected patients with limited tumor volume and non-eligibility for other invasive treatments. Moreover, RT combined with a radiation sensitizer (RS) to increase the therapeutic ratio has shown promising results in select studies, prompting further investigation of this combination. With the undetermined role of RT in treatment guidelines and variation in patterns of treatment failure after RT in patient with HCC, useful biomarkers to guide RT decision-making and selection of patients are needed and emerging. Key Message The objective of this review is to summarize the current RS with SBRT schemes and biomarkers for patient selection used to maximize the effect of RT on HCC. PMID:27493896

  16. Place of radiotherapy in the treatment of synovial sarcoma

    SciTech Connect

    Carson, J.H.; Harwood, A.R.; Cummings, B.J.; Fornasier, V.; Langer, F.; Quirt, I.

    1981-01-01

    This paper reviews 36 patients with synovial sarcoma; 18 were referred within three months of surgery. None had undergone en bloc excision and all were treated with post-operative radiotherapy. Local control and survival were analyzed with respect to Tumor Node Metastasis Classification, histology, site of primary and surgical procedure. Eight patients with T1-2N0M0 tumors were alive and well (minimum two year follow-up) following excision and radiotherapy; 7 had a normally functional extremity. In contrast, only one of 8 patients with T3N0M0 tumors is alive and well. Seven of 8 patients with well or moderately differentiated histology were alive and well whereas no patient with poorly differentiated histologies survived. Six of 7 patients were alive and well if their tumor was distal to the elbow or knee whereas none of those who had a primary thigh synovial sarcoma survived. Eighteen patients were referred with recurrent disease and 2 were salvaged. A management policy is proposed for synovial sarcoma with the integrated use of surgery, radiation and chemotherapy; it emphasizes optimal cure rates and a functional extremity reserving amputation for salvage.

  17. Prevention of accidental exposure in radiotherapy: the risk matrix approach.

    PubMed

    Vilaragut, J J; Duménigo, C; Delgado, J M; Morales, J; McDonnell, J D; Ferro, R; Ortiz López, P; Ramírez, M L; Pérez Mulas, A; Papadopulos, S; Gonçalves, M; López Morones, R; Sánchez Cayuela, C; Cascajo Castresana, A; Somoano, F; Álvarez, C; Guillén, A; Rodríguez, M; Pereira, P P; Nader, A

    2013-02-01

    Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions. PMID:23274816

  18. [Interest of FDG-PET for lung cancer radiotherapy].

    PubMed

    Thureau, S; Mezzani-Saillard, S; Modzelewski, R; Edet-Sanson, A; Dubray, B; Vera, P

    2011-10-01

    The recent advances in medical imaging have profoundly altered the radiotherapy of non-small cell lung cancers (NSCLC). A meta-analysis has confirmed the superiority of FDG PET-CT over CT for initial staging. FDG PET-CT improves the reproducibility of target volume delineation, especially close to the mediastinum or in the presence of atelectasia. Although not formally validated by a randomized trial, the reduction of the mediastinal target volume, by restricting the irradiation to FDG-avid nodes, is widely accepted. The optimal method of delineation still remains to be defined. The role of FDG PET-CT in monitoring tumor response during radiotherapy is under investigation, potentially opening the way to adapting the treatment modalities to tumor radiation sensitivity. Other tracers, such as F-miso (hypoxia), are also under clinical investigation. To avoid excessive delays, the integration of PET-CT in routine practice requires quick access to the imaging equipment, technical support (fusion and image processing) and multidisciplinary delineation of target volumes. PMID:21880535

  19. Standard and Nonstandard Craniospinal Radiotherapy Using Helical TomoTherapy

    SciTech Connect

    Parker, William; Brodeur, Marylene; Roberge, David; Freeman, Carolyn

    2010-07-01

    Purpose: To show the advantages of planning and delivering craniospinal radiotherapy with helical TomoTherapy (TomoTherapy Inc., Madison, WI) by presenting 4 cases treated at our institution. Methods and Materials: We first present a standard case of craniospinal irradiation in a patient with recurrent myxopapillary ependymoma (MPE) and follow this with 2 cases requiring differential dosing to multiple target volumes. One of these, a patient with recurrent medulloblastoma, required a lower dose to be delivered to the posterior fossa because the patient had been previously irradiated to the full dose, and the other required concurrent boosts to leptomeningeal metastases as part of his treatment for newly diagnosed MPE. The final case presented is a patient with pronounced scoliosis who required spinal irradiation for recurrent MPE. Results: The four cases presented were planned and treated successfully with Helical Tomotherapy. Conclusions: Helical TomoTherapy delivers continuous arc-based intensity-modulated radiotherapy that gives high conformality and excellent dose homogeneity for the target volumes. Increased healthy tissue sparing is achieved at higher doses albeit at the expense of larger volumes of tissue receiving lower doses. Helical TomoTherapy allows for differential dosing of multiple targets, resulting in very elegant dose distributions. Daily megavoltage computed tomography imaging allows for precision of patient positioning, permitting a reduction in planning margins and increased healthy tissue sparing in comparison with standard techniques.