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Sample records for radiotherapy treatment process

  1. 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).

  2. Respiration gated radiotherapy treatment: a technical study

    NASA Astrophysics Data System (ADS)

    Kubo, Hideo D.; Hill, Bruce C.

    1996-01-01

    In order to optimize external-beam conformal radiotherapy, patient movement during treatment must be minimized. For treatment on the upper torso, the target organs are known to move substantially due to patient respiration. This paper deals with the technical aspects of gating the radiotherapy beam synchronously with respiration: the optimal respiration monitoring system, measurements of organ displacement and linear accelerator gating. Several respiration sensors including a thermistor, a thermocouple, a strain gauge and a pneumotachograph were examined to find the optimal sensor. The magnitude of breast, chest wall and lung motion were determined using playback of fluoroscopic x-ray images recorded on a VCR during routine radiotherapy simulation. Total dose, beam symmetry and beam uniformity were examined to determine any effects on the Varian 2100C linear accelerator due to gating.

  3. 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.

  4. 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. PMID:25848119

  5. Tsallis entropy approach to radiotherapy treatments

    NASA Astrophysics Data System (ADS)

    Sotolongo-Grau, O.; Rodriguez-Perez, D.; Sotolongo-Costa, O.; Antoranz, J. C.

    2013-05-01

    The biological effect of one single radiation dose on a living tissue has been described by several radiobiological models. However, the fractionated radiotherapy requires to account for a new magnitude: time. In this paper we explore the biological consequences posed by the mathematical prolongation of a previous model to fractionated treatment. Nonextensive composition rules are introduced to obtain the survival fraction and equivalent physical dose in terms of a time dependent factor describing the tissue trend towards recovering its radioresistance (a kind of repair coefficient). Interesting (known and new) behaviors are described regarding the effectiveness of the treatment which is shown to be fundamentally bound to this factor. The continuous limit, applicable to brachytherapy, is also analyzed in the framework of nonextensive calculus. Here a coefficient that rules the time behavior also arises. All the results are discussed in terms of the clinical evidence and their major implications are highlighted.

  6. Radiotherapy treatments using Tsallis entropy statistical approach

    NASA Astrophysics Data System (ADS)

    D, Rodríguez-Pérez; O, Sotolongo-Grau; O, Sotolongo-Costa; C, Antoranz J.

    2014-03-01

    Several radiobiological models mimic the biologic effect of one single radiation dose on a living tissue. However, the actual fractionated radiotherapy requires accounting for a new magnitude, i.e., time. Here, we explore the biological consequences posed by the mathematical prolongation of a previous single radiation model to fractionated treatment. The survival fraction is obtained, together with the equivalent physical dose, in terms of a time dependent factor (similar to a repair coefficient) describing the tissue trend to recovering its radioresistance. The model describes how dose fractions add up to obtain the equivalent dose and how the repair coefficient poses a limit to reach an equivalent dose equal to the critical one that would completely annihilate the tumor. On the other hand, the surrounding healthy tissue is a limiting factor to treatment planning. This tissue has its own repair coefficient and thus should limit the equivalent dose of a treatment. Depending on the repair coefficient and the critical dose of each tissue, unexpected results (failure to fully remove the tumor) can be obtained. To illustrate these results and predictions, some realistic example calculations will be performed using parameter values within actual clinical ranges. In conclusion, the model warns about treatment limitations and proposes ways to overcome them.

  7. System Toward Automation in Radiotherapy Treatment: START

    NASA Astrophysics Data System (ADS)

    Cheng, Andrew Y. S.; Tsoi, Kenneth Y. P.

    1994-10-01

    START is a new automation system invented for nasopharyngeal carcinoma treatment. A laser scanner system capable of non-contact digitization of 3D surface is used to digitize the contours of the patient's face, shoulder and special landmark reference features of the patient. These features are stored in the computer in 3D digitized format. The digitized facial features with traced landmark reference features are used for fabrication of a true sized wood-particle laminates mould by a computer numerical controlled milling system. A Cobex mask is formed on this mould by using vacuum forming technique. With an image analysis and computer aided design system, the X-ray film with treatment window marked is traced automatically and converted to match the prescanned 3D information. A computer controlled 6-axis robot can precisely mark out the required areas on the Cobex cast for treatment. Finally, the patient receives radiotherapy treatment with the Cobex case as a positioning registration device. The new system will replace the manual procedure with better patient comfort, higher efficiency and enhanced accuracy.

  8. 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

  9. 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.

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

    PubMed

    Zhang, Ai-Wei; Guo, Wei-Hua; Qi, Ya-Fei; Wang, Jian-Zhen; Ma, Xiang-Xing; Yu, De-Xin

    2016-12-01

    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. PMID:27255899

  12. 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.

  13. Intensity-modulated radiotherapy in the treatment of breast cancer.

    PubMed

    Dayes, I; Rumble, R B; Bowen, J; Dixon, P; Warde, P

    2012-09-01

    Intensity-modulated radiotherapy (IMRT) is a newer method of radiotherapy that uses beams with multiple intensity levels for any single beam, allowing concave dose distributions and tighter margins than those possible using conventional radiotherapy. 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 breast cancer to quantify the potential benefits of this new technology and to make recommendations for radiation treatment programmes considering adopting this technique. Providing that avoidance of acute adverse effects associated with radiation is an outcome of interest, then IMRT is recommended over tangential radiotherapy after breast-conserving surgery, based on a review of six published reports including 2012 patients. There were insufficient data to recommend IMRT over standard tangential radiotherapy for reasons of oncological outcomes or late toxicity. Future research should focus on studies with longer follow-up and provide data on late toxicity and disease recurrence rates. PMID:22748561

  14. 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

  15. Treatment outcome of postoperative radiotherapy for retroperitoneal sarcoma

    PubMed Central

    Lee, Hyun Jin; Kwon, Tae-Won; Yook, Jeong Hwan; Kim, Song-Cheol; Han, Duck-Jong; Kim, Choung-Soo; Ahn, Hanjong; Chang, Heung Moon; Ahn, Jin-Hee; Jwa, Eun Jin; Lee, Sang-Wook; Kim, Jong Hoon; Choi, Eun Kyung; Shin, Seong Soo; Ahn, Seung Do

    2011-01-01

    Purpose To evaluate the treatment outcome and prognostic factor after postoperative radiotherapy in retroperitoneal sarcoma. Materials and Methods Forty patients were treated with surgical resection and postoperative radiotherapy for retroperitoneal sarcoma from August 1990 to August 2008. Treatment volume was judged by the location of initial tumor and surgical field, and 45-50 Gy of radiation was basically delivered and additional dose was considered to the high-risk area. Results The median follow-up period was 41.4 months (range, 3.9 to 140.6 months). The 5-year overall survival (OS) was 51.8% and disease free survival was 31.5%. The 5-year locoregional recurrence free survival was 61.9% and distant metastasis free survival was 50.6%. In univariate analysis, histologic type (p = 0.006) was the strongest prognostic factor for the OS and histologic grade (p = 0.044) or resection margin (p = 0.032) had also effect on the OS. Histologic type (p = 0.004) was unique significant prognostic factor for the actuarial local control. Conclusion Retroperitoneal sarcoma still remains as a poor prognostic disease despite the combined modality treatment including surgery and postoperative radiotherapy. Selective dose-escalation of radiotherapy or combination of effective chemotherapeutic agent must be considered to improve the treatment result especially for the histopathologic type showing poor prognosis. PMID:22984679

  16. Automatic liver contouring for radiotherapy treatment planning.

    PubMed

    Li, Dengwang; Liu, Li; Kapp, Daniel S; Xing, Lei

    2015-10-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems.The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours.The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  17. Automatic liver contouring for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Li, Dengwang; Liu, Li; Kapp, Daniel S.; Xing, Lei

    2015-09-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems. The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours. The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  18. Functional and molecular image guidance in radiotherapy treatment planning optimization.

    PubMed

    Das, Shiva K; Ten Haken, Randall K

    2011-04-01

    Functional and molecular imaging techniques are increasingly being developed and used to quantitatively map the spatial distribution of parameters, such as metabolism, proliferation, hypoxia, perfusion, and ventilation, onto anatomically imaged normal organs and tumor. In radiotherapy optimization, these imaging modalities offer the promise of increased dose sparing to high-functioning subregions of normal organs or dose escalation to selected subregions of the tumor as well as the potential to adapt radiotherapy to functional changes that occur during the course of treatment. The practical use of functional/molecular imaging in radiotherapy optimization must take into cautious consideration several factors whose influences are still not clearly quantified or well understood including patient positioning differences between the planning computed tomography and functional/molecular imaging sessions, image reconstruction parameters and techniques, image registration, target/normal organ functional segmentation, the relationship governing the dose escalation/sparing warranted by the functional/molecular image intensity map, and radiotherapy-induced changes in the image intensity map over the course of treatment. The clinical benefit of functional/molecular image guidance in the form of improved local control or decreased normal organ toxicity has yet to be shown and awaits prospective clinical trials addressing this issue. PMID:21356479

  19. 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.

  20. 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

  1. Temporal Optimization of Radiotherapy Treatment Fractions

    SciTech Connect

    Stewart, Robert D. ); Traub, Richard J. )

    2001-01-01

    Absorbed dose calculations for 1 MeV, monodirectional photon beams targeted at an idealized neck cancer have been performed using the MCNP computer code. The dose-depth profiles for the individual beams were then used to calculate the cell-killing effects of representative treatment designs using the lethal and potentially lethal (LPL) radiobiological model. Our calculations, which are based on LPL parameter values for colon adenocarcinoma cells, suggest that increasing the time required to deliver each dose fraction from less than a minute up to 1 or 2 hours can decrease the overall cell-killing effects of some treatments by factors as high as 2 to 20. Moreover, dose protraction effects alter the iso-effect treatment dose by factors on the order of 5 to 10%. That is, a 75 Gy treatment produces about the same tumor control probability (TCP) as a 70 Gy treatment if the dose fractions are delivered in 1 to 2 hours instead of a few minutes. American Nuclear Society (ANS) Topical Meeting on Radiation Protection for our National Priorities, Medicine, the Environment, and the Legacy (RPS 2000), Spokane, WA, September 17-21, 2000.

  2. The synergistic effects of traditional Chinese herbs and radiotherapy for cancer treatment

    PubMed Central

    JIA, LILI; MA, SHUMEI; HOU, XUE; WANG, XIN; QASED, ABU BAKER LAYTH; SUN, XUEFEI; LIANG, NAN; LI, HUICHENG; YI, HEQING; KONG, DEJUAN; LIU, XIAODONG; FAN, FEIYUE

    2013-01-01

    Traditional Chinese medicine (TCM) has been demonstrated to have potent cytotoxic activity against certain malignant tumors. Ionizing radiation (IR) is one of the most effective methods used in the clinical treatment of cancer. The drawback of a single formula is that it limits the treatment efficacy for cancer, while comprehensive strategies require additional theoretical support. However, a combination of different antitumor treatment modalities is advantageous in restricting the non-specific toxicity often observed with an extremely high dose of a single regimen. The induction of apoptotic cell death is a significant process in tumor cells following radiotherapy or chemotherapy, and resistance to these treatments has been linked to a low propensity for apoptosis. Autophagy is a response of cancer cells to IR or chemotherapy, and involves the prominent formation of autophagic vacuoles in the cytoplasm. In this review, the synergistic effects of TCM and radiotherapy are summarized and the underlying mechanisms are illustrated, providing new therapeutic strategies for cancer. PMID:23760551

  3. Electron Density Calibration for Radiotherapy Treatment Planning

    SciTech Connect

    Herrera-Martinez, F.; Rodriguez-Villafuerte, M.; Martinez-Davalos, A.; Ruiz-Trejo, C.; Celis-Lopez, M. A.; Larraga-Gutierrez, J. M.; Garcia-Garduno, A.

    2006-09-08

    Computed tomography (CT) images are used as basic input data for most modern radiosurgery treatment planning systems (TPS). CT data not only provide anatomic information to delineate target volumes, but also allow the introduction of corrections for tissue inhomogeneities into dose calculations during the treatment planning procedure. These corrections involve the determination of a relationship between tissue electron density ({rho}e) and their corresponding Hounsfield Units (HU). In this work, an elemental analysis of different commercial tissue equivalent materials using Scanning Electron Microscopy was carried out to characterize their chemical composition. The tissue equivalent materials were chosen to ensure a large range of {rho}e to be included in the CT scanner calibration. A phantom was designed and constructed with these materials to simulate the size of a human head.

  4. Electron Density Calibration for Radiotherapy Treatment Planning

    NASA Astrophysics Data System (ADS)

    Herrera-Martínez, F.; Rodríguez-Villafuerte, M.; Martínez-Dávalos, A.; Ruiz-Trejo, C.; Celis-López, M. A.; Lárraga-Gutiérrez, J. M.; García-Garduño, A.

    2006-09-01

    Computed tomography (CT) images are used as basic input data for most modern radiosurgery treatment planning systems (TPS). CT data not only provide anatomic information to delineate target volumes, but also allow the introduction of corrections for tissue inhomogeneities into dose calculations during the treatment planning procedure. These corrections involve the determination of a relationship between tissue electron density (ρe) and their corresponding Hounsfield Units (HU). In this work, an elemental analysis of different commercial tissue equivalent materials using Scanning Electron Microscopy was carried out to characterize their chemical composition. The tissue equivalent materials were chosen to ensure a large range of ρe to be included in the CT scanner calibration. A phantom was designed and constructed with these materials to simulate the size of a human head.

  5. Personnel radiation dose considerations in the use of an integrated PET-CT scanner for radiotherapy treatment planning.

    PubMed

    Carson, K J; Young, V A L; Cosgrove, V P; Jarritt, P H; Hounsell, A R

    2009-11-01

    The acquisition of radiotherapy planning scans on positron emission tomography (PET)-CT scanners requires the involvement of radiotherapy radiographers. This study assessed the radiation dose received by these radiographers during this process. Radiotherapy planning (18)F-fluorodeoxyglucose ((18)F-FDG) PET-CT scans were acquired for 28 non-small cell lung cancer patients. In order to minimise the radiation dose received, a two-stage process was used in which the most time-consuming part of the set-up was performed before the patient received their (18)F-FDG injection. Throughout this process, the radiographers wore electronic personal dosemeters and recorded the doses received at different stages of the process. The mean total radiation dose received by a radiotherapy radiographer was 5.1+/-2.6 microSv per patient. The use of the two-stage process reduced the time spent in close proximity to the patient by approximately a factor of four. The two-stage process was effective in keeping radiation dose to a minimum. The use of a pre-injection set-up session reduces the radiation dose to the radiotherapy radiographers because of their involvement in PET-CT radiotherapy treatment planning scans by approximately a factor of three. PMID:19332513

  6. 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.

  7. Multi-energy imagers for a radiotherapy treatment environment

    NASA Astrophysics Data System (ADS)

    Antonuk, Larry E.; Liu, Langechuan; Liang, Albert K.; El-Mohri, Youcef; Zhao, Qihua; Koniczek, Martin; Jiang, Hao

    2015-03-01

    Over the last ~15 years, the central goal in external beam radiotherapy of maximizing dose to the tumor while minimizing dose to surrounding normal tissues has been greatly facilitated by the development and clinical implementation of many innovations. These include megavoltage active matrix flat-panel imagers (MV AMFPIs) designed to image the treatment beam, and separate kilovoltage (kV) AMFPIs and x-ray sources designed to provide high-contrast projection and cone-beam CT images in the treatment room. While these systems provide clinically valuable information, a variety of advantages would accrue through introduction of the capability to produce clinically useful, high quality imaging information at multiple energies (e.g., kV and MV) from a single detector along the treatment beam direction. One possible approach for achieving this goal involves substitution of the x-ray converters used in conventional MV AMFPIs with thick, segmented crystalline scintillators designed for dual-energy operation, coupled with the addition of x-ray imaging beams that contain a significant diagnostic component. A second approach involves introduction of a large area, monolithic array of photon counting pixels with multiple energy thresholds and event counters, which could provide multi-spectral views of the treatment beam with improved contrast. In this paper, the motivations behind, and the merits of each approach are described. In addition, prospects for such dual-energy imagers and photon counting array designs are discussed in the context of the radiotherapy environment.

  8. 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

  9. A Monte Carlo dose calculation tool for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Ma, C.-M.; Li, J. S.; Pawlicki, T.; Jiang, S. B.; Deng, J.; Lee, M. C.; Koumrian, T.; Luxton, M.; Brain, S.

    2002-05-01

    A Monte Carlo user code, MCDOSE, has been developed for radiotherapy treatment planning (RTP) dose calculations. MCDOSE is designed as a dose calculation module suitable for adaptation to host RTP systems. MCDOSE can be used for both conventional photon/electron beam calculation and intensity modulated radiotherapy (IMRT) treatment planning. MCDOSE uses a multiple-source model to reconstruct the treatment beam phase space. Based on Monte Carlo simulated or measured beam data acquired during commissioning, source-model parameters are adjusted through an automated procedure. Beam modifiers such as jaws, physical and dynamic wedges, compensators, blocks, electron cut-outs and bolus are simulated by MCDOSE together with a 3D rectilinear patient geometry model built from CT data. Dose distributions calculated using MCDOSE agreed well with those calculated by the EGS4/DOSXYZ code using different beam set-ups and beam modifiers. Heterogeneity correction factors for layered-lung or layered-bone phantoms as calculated by both codes were consistent with measured data to within 1%. The effect of energy cut-offs for particle transport was investigated. Variance reduction techniques were implemented in MCDOSE to achieve a speedup factor of 10-30 compared to DOSXYZ.

  10. Optimized radiotherapy treatment planning using the Complication Probability Factor (CPF)

    SciTech Connect

    Wolbarst, A.B.; Sternick, E.S.; Curran, B.H.; Dritschilo, A.

    1980-06-01

    A major obstacle to effective computerized optimization of radiotherapy treatment planning has been the lack of a biologically meaningful and clinically useful objective function. Our approach employs a Complication Probability Factor (CPF) based directly on radiobiological principles and clinical data. The CPF measures the likelihood that a given dose distribution will lead to serious complications in the patient as a result of damage to healthy tissue. A computerized search can be made for a treatment plan which delivers an acceptable tumoricidal dose, yet minimizes the CPF as averaged over the total volume of healthy tissue irradiated. The program is run on a PDP 11/55 in conjunction with a commercial treatment planning package.

  11. Treatment of brain metastases of renal cell cancer with combined hypofractionated stereotactic radiotherapy and whole brain radiotherapy with hippocampal sparing

    PubMed Central

    VRÁNA, DAVID; ŠTUDENTOVÁ, HANA; MATZENAUER, MARCEL; VLACHOVÁ, ZUZANA; CWIERTKA, KAREL; GREMLICA, DAVID; KALITA, ONDŘEJ

    2016-01-01

    Renal cell cancer patients with brain metastatic disease generally have poor prognosis. Treatment options include surgery, radiotherapy, targeted therapy or best supportive care with respect to disease burden, patient preference and performance status. In the present case report the radiotherapy technique combining whole brain radiotherapy with hippocampal sparing (hippocampal avoidance whole brain radiotherapy HA-WBRT) and hypofractionated stereotactic radiotherapy (SRT) of the brain metastases is performed in a patient with metastatic renal cell carcinoma. HA-WBRT was administered to 30 Gy in 10 fractions with sparing of the hippocampal structures and SRT of 21 Gy in 3 fractions to brain metastases which has preceded the HA-WBRT. Two single arc volumetric modulated arc radiotherapy (VMAT) plans were prepared using Monaco planning software. The HA-WBRT treatment plan achieved the following results: D2=33.91 Gy, D98=25.20 Gy, D100=14.18 Gy, D50=31.26 Gy. The homogeneity index was calculated as a deduction of the minimum dose in 2% and 98% of the planning target volume (PTV), divided by the minimum dose in 50% of the PTV. The maximum dose to the hippocampus was 17.50 Gy and mean dose was 11.59 Gy. The following doses to organs at risk (OAR) were achieved: Right opticus Dmax, 31.96 Gy; left opticus Dmax, 30.96 Gy; chiasma D max, 32,76 Gy. The volume of PTV for stereotactic radiotherapy was 3,736 cm3, with coverage D100=20.95 Gy and with only 0.11% of the PTV being irradiated to dose below the prescribed dose. HA-WBRT with SRT represents a feasible technique for radiotherapy of brain metastatic disease, however this technique is considerably demanding on departmental equipment and staff time/experience. PMID:27313693

  12. Volumetric modulated arc therapy for hippocampal-sparing radiotherapy in transformed low-grade glioma: A treatment planning case report.

    PubMed

    Kazda, T; Pospisil, P; Vrzal, M; Sevela, O; Prochazka, T; Jancalek, R; Slampa, P; Laack, N N

    2015-05-01

    Timing of radiotherapy for low-grade gliomas is still controversial due to concerns of possible adverse late effects. Prevention of possible late cognitive sequelae by hippocampal avoidance has shown promise in phase II trials. A patient with progressive low-grade glioma with gradual dedifferentiation into anaplastic astrocytoma is presented along with description of radiotherapy planning process attempting to spare the hippocampus. To our knowledge, this is the first described case using volumetric modulated arc technique to spare hippocampus during transformed low-grade glioma radiotherapy. Using modern intensity-modulated radiotherapy systems it is possible to selectively spare hippocampus together with other standard organs at risk. For selected patients, an attempt to spare hippocampus can be considered as long as other dose characteristics are not significantly compromised compared to standard treatment plan created without any effort to avoid hippocampus. PMID:25835374

  13. Outcomes of Kimura's disease after radiotherapy or nonradiotherapeutic treatment modalities

    SciTech Connect

    Chang, Ah Ram; Kim, Kyubo; Kim, Hak Jae; Kim, Il Han . E-mail: ihkim@snu.ac.kr; Park, Charn Il; Jun, Yoon Kyung

    2006-07-15

    Purpose: To evaluate the clinical outcome of Kimura's disease and to identify the optimal treatment regimen for Kimura's disease. Methods and Materials: Between 1984 and 2003, 14 patients with Kimura's disease were treated with radiotherapy (RT) and 9 patients were treated with local excision or systemic steroids. The radiation doses ranged from 20 to 45 Gy. Immunohistochemical studies were performed in 13 cases. Results: At RT completion, a marked response in terms of tumor size was noted in most cases. The median follow-up was 65 months. Local control was obtained in 9 (64.3%) of the 14 in the RT group and in 2 (22.2%) of the 9 in the non-RT group. No secondary malignancies were observed in the RT group. Conclusion: These results supports the finding that RT is more effective against Kimura's disease. Simple or immunohistochemical features did not influence the treatment outcome.

  14. The NUKDOS software for treatment planning in molecular radiotherapy.

    PubMed

    Kletting, Peter; Schimmel, Sebastian; Hänscheid, Heribert; Luster, Markus; Fernández, Maria; Nosske, Dietmar; Lassmann, Michael; Glatting, Gerhard

    2015-09-01

    The aim of this work was the development of a software tool for treatment planning prior to molecular radiotherapy, which comprises all functionality to objectively determine the activity to administer and the pertaining absorbed doses (including the corresponding error) based on a series of gamma camera images and one SPECT/CT or probe data. NUKDOS was developed in MATLAB. The workflow is based on the MIRD formalism For determination of the tissue or organ pharmacokinetics, gamma camera images as well as probe, urine, serum and blood activity data can be processed. To estimate the time-integrated activity coefficients (TIAC), sums of exponentials are fitted to the time activity data and integrated analytically. To obtain the TIAC on the voxel level, the voxel activity distribution from the quantitative 3D SPECT/CT (or PET/CT) is used for scaling and weighting the TIAC derived from the 2D organ data. The voxel S-values are automatically calculated based on the voxel-size of the image and the therapeutic nuclide ((90)Y, (131)I or (177)Lu). The absorbed dose coefficients are computed by convolution of the voxel TIAC and the voxel S-values. The activity to administer and the pertaining absorbed doses are determined by entering the absorbed dose for the organ at risk. The overall error of the calculated absorbed doses is determined by Gaussian error propagation. NUKDOS was tested for the operation systems Windows(®) 7 (64 Bit) and 8 (64 Bit). The results of each working step were compared to commercially available (SAAMII, OLINDA/EXM) and in-house (UlmDOS) software. The application of the software is demonstrated using examples form peptide receptor radionuclide therapy (PRRT) and from radioiodine therapy of benign thyroid diseases. For the example from PRRT, the calculated activity to administer differed by 4% comparing NUKDOS and the final result using UlmDos, SAAMII and OLINDA/EXM sequentially. The absorbed dose for the spleen and tumour differed by 7% and 8

  15. 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

  16. The effects of delays in radiotherapy treatment on tumour control

    NASA Astrophysics Data System (ADS)

    Wyatt, R. M.; Beddoe, A. H.; Dale, R. G.

    2003-01-01

    There is often a considerable delay from initial tumour diagnosis to the start of radiotherapy treatment, which may be due to factors such as waiting lists and referral delays. This paper uses widely published models and clinical parameters to calculate the effect of delays in treatment on local tumour control for four different types of tumour - squamous cell carcinoma (head and neck), breast, cervix and prostate. The Poisson model for tumour control probability (TCP), an exponential function for tumour growth and the linear quadratic model of cell kill are used to calculate the change in TCP for delays between diagnosis and treatment of up to 100 days. Typical values of the clinical parameters have been taken from the literature; these include α and β, σα, tumour size at diagnosis, pre-treatment doubling time, delay in onset of accelerated repopulation and doubling time during treatment. It is acknowledged that there are limitations in the reliability of these data for predicting absolute values of tumour control, but models are still useful for predicting how changes in treatment parameters are likely to affect the outcome. It is shown that for fast-growing tumours a delay of 1-2 months can have a significant adverse effect on the outcome, whereas for slow-growing tumours such as Ca prostate a delay of a few months does not significantly reduce the probability of tumour control. These calculations show the importance of ensuring that delays from diagnosis through to treatment are minimized, especially for patients with rapidly proliferating tumours.

  17. Does Treatment Duration Affect Outcome After Radiotherapy for Prostate Cancer?

    SciTech Connect

    D'Ambrosio, David J.; Li Tianyu; Horwitz, Eric M.; Chen, David Y.T.; Pollack, Alan; Buyyounouski, Mark K.

    2008-12-01

    Purpose: The protraction of external beam radiotherapy (RT) time is detrimental in several disease sites. In prostate cancer, the overall treatment time can be considerable, as can the potential for treatment breaks. We evaluated the effect of elapsed treatment time on outcome after RT for prostate cancer. Methods and Materials: Between April 1989 and November 2004, 1,796 men with prostate cancer were treated with RT alone. The nontreatment day ratio (NTDR) was defined as the number of nontreatment days divided by the total elapsed days of RT. This ratio was used to account for the relationship between treatment duration and total RT dose. Men were stratified into low risk (n = 789), intermediate risk (n = 798), and high risk (n = 209) using a single-factor model. Results: The 10-year freedom from biochemical failure (FFBF) rate was 68% for a NTDR <33% vs. 58% for NTDR {>=}33% (p = 0.02; BF was defined as a prostate-specific antigen nadir + 2 ng/mL). In the low-risk group, the 10-year FFBF rate was 82% for NTDR <33% vs. 57% for NTDR {>=}33% (p = 0.0019). The NTDR was independently predictive for FFBF (p = 0.03), in addition to T stage (p = 0.005) and initial prostate-specific antigen level (p < 0.0001) on multivariate analysis, including Gleason score and radiation dose. The NTDR was not a significant predictor of FFBF when examined in the intermediate-risk group, high-risk group, or all risk groups combined. Conclusions: A proportionally longer treatment duration was identified as an adverse factor in low-risk patients. Treatment breaks resulting in a NTDR of {>=}33% (e.g., four or more breaks during a 40-fraction treatment, 5 d/wk) should be avoided.

  18. 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.

  19. Precision, high dose radiotherapy: helium ion treatment of uveal melanoma

    SciTech Connect

    Saunders, W.M.; Char, D.H.; Quivey, J.M.; Castro, J.R.; Chen, G.T.Y.; Collier, J.M.; Cartigny, A.; Blakely, E.A.; Lyman, J.T.; Zink, S.R.

    1985-02-01

    The authors report on 75 patients with uveal melanoma who were treated by placing the Bragg peak of a helium ion beam over the tumor volume. The technique localizes the high dose region very tightly around the tumor volume. This allows critical structures, such as the optic disc and the macula, to be excluded from the high dose region as long as they are 3 to 4 mm away from the edge of the tumor. Careful attention to tumor localization, treatment planning, patient immobilization and treatment verification is required. With a mean follow-up of 22 months (3 to 60 months) the authors have had only five patients with a local recurrence, all of whom were salvaged with another treatment. Pretreatment visual acuity has generally been preserved as long as the tumor edge is at least 4 mm away from the macula and optic disc. The only serious complication to date has been an 18% incidence of neovascular glaucoma in the patients treated at our highest dose level. Clinical results and details of the technique are presented to illustrate potential clinical precision in administering high dose radiotherapy with charged particles such as helium ions or protons.

  20. Hypofractionated radiotherapy in the treatment of early breast cancer

    PubMed Central

    Plataniotis, George

    2010-01-01

    Radiotherapy (RT) after tumorectomy in early breast cancer patients is an established treatment modality which conventionally takes 6-7 wk to complete. Shorter RT schedules have been tested in large multicentre randomized trials and have shown equivalent results to that of standard RT (50 Gy in 25 fractions) in terms of local tumor control, patient survival and late post-radiation effects. Some of those trials have now completed 10 years of follow-up with encouraging results for treatments of 3-4 wk and a total RT dose to the breast of 40-42.5 Gy with or without boost. A reduction of 50% in treatment time makes those RT schedules attractive for both patients and health care providers and would have a significant impact on daily RT practice around the world, as it would accelerate patient turnover and save health care resources. However, in hypofractionated RT, a higher (than the conventional 1.8-2 Gy) dose per fraction is given and should be managed with caution as it could result in a higher rate of late post-radiation effects in breast, heart, lungs and the brachial plexus. It is therefore advisable that both possible dose inhomogeneity and normal tissue protection should be taken into account and the appropriate technology such as three-dimensional/intensity modulated radiation therapy employed in clinical practice, when hypofractionation is used. PMID:21160631

  1. Intensity-modulated radiotherapy for neoadjuvant treatment of gastric cancer

    SciTech Connect

    Knab, Brian; Rash, Carla; Farrey, Karl; Jani, Ashesh B. . E-mail: jani@rover.uchicago.edu

    2006-01-01

    Radiation therapy plays an integral role in the treatment of gastric cancer in the postsurgery setting, the inoperable/palliative setting, and, as in the case of the current report, in the setting of neoadjuvant therapy prior to surgery. Typically, anterior-posterior/posterior-anterior (AP/PA) or 3-field techniques are used. In this report, we explore the use of intensity-modulated radiotherapy (IMRT) treatment in a patient whose care was transferred to our institution after 3-field radiotherapy (RT) was given to a dose of 30 Gy at an outside institution. If the 3-field plan were continued to 50 Gy, the volume of irradiated liver receiving greater than 30 Gy would have been unacceptably high. To deliver the final 20 Gy, an opposed parallel AP/PA plan and an IMRT plan were compared to the initial 3-field technique for coverage of the target volume as well as dose to the kidneys, liver, small bowel, and spinal cord. Comparison of the 3 treatment techniques to deliver the final 20 Gy revealed reduced median and maximum dose to the whole kidney with the IMRT plan. For this 20-Gy boost, the volume of irradiated liver was lower for both the IMRT plan and the AP/PA plan vs. the 3-field plan. Comparing the IMRT boost plan to the AP/PA boost-dose range (<10 Gy) in comparison to the AP/PA plan; however, the IMRT plan irradiated a smaller liver volume within the higher dose region (>10 Gy) in comparison to the AP/PA plan. The IMRT boost plan also irradiated a smaller volume of the small bowel compared to both the 3-field plan and the AP/PA plan, and also delivered lower dose to the spinal cord in comparison to the AP/PA plan. Comparison of the composite plans revealed reduced dose to the whole kidney using IMRT. The V20 for the whole kidney volume for the composite IMRT plan was 30% compared to approximately 60% for the composite AP/PA plan. Overall, the dose to the liver receiving greater than 30 Gy was lower for the composite IMRT plan and was well below acceptable limits

  2. Radiotherapy.

    PubMed

    Adamietz, Irenaus A

    2010-01-01

    The intrathoracic growth of the tumor causes several severe symptoms as cough, dyspnea, chest pain, hemoptysis, hoarseness, anorexia/nausea, and dysphagia. In patients with manifest or threatening symptoms radiotherapy (RT) as an effective measure should be implemented into the management concept. Palliative RT radiotherapy prefers short hypofractionated schemas (e.g. 10 x 3 Gy, 4 x 5 Gy, 2 x 8 Gy, 1 x 10 Gy). Careful radiation planning supports the precision of palliative RT and reduces significantly the complication rate. A good response and prolonged palliation effects (6-12 months) can be achieved in many cases. However, the minimum biologically equivalent dose should not be less than 35 Gy. RT produces a good outcome in all types of metastases of lung carcinoma. In emergencies like VCSS or spinal cord compression RT should be initiated immediately. The selection of the optimal therapy for locally advanced lung carcinoma with malignant airway obstruction is difficult. Both brachytherapy and percutaneous irradiation are effective, however published results including local a sum of response, functionality and life quality demonstrates more benefit by percutaneous RT. Due to different physical properties of these two methods the combination of brachytherapy and external beam irradiation may be advantageous. PMID:19955803

  3. [Axillary treatment in breast cancer: surgery, radiotherapy, or none of these?].

    PubMed

    Boersma, Liesbeth J; van der Sangen, Maurice J C

    2015-01-01

    The AMAROS trial showed that substituting axillary lymph node dissection by radiotherapy of the axillary and periclavicular nodes (ART) in patients with sentinel node (SN) metastases results in less lymphoedema, without a significant difference in the 5-year axillary recurrence rate (ARR). Three surgical studies showed no increase in ARR after omitting axillary treatment in cases of limited SN metastases, provided that adjuvant systemic therapy and tangential breast radiotherapy were applied. On the other hand, several recent radiotherapy trials, including a meta-analysis by the Early Breast Cancer Trialists' Collaborative Group, showed that regional radiotherapy improves disease-free survival where there are positive axillary nodes. In view of the low ARR and good overall survival with contemporary breast cancer treatments, limiting axillary treatment and its associated morbidity is a logical development. However, it is too early to omit axillary treatment in all SN-positive patients. ART is a safe next step in reducing axillary treatment. PMID:26488194

  4. Retrieval with Clustering in a Case-Based Reasoning System for Radiotherapy Treatment Planning

    NASA Astrophysics Data System (ADS)

    Khussainova, Gulmira; Petrovic, Sanja; Jagannathan, Rupa

    2015-05-01

    Radiotherapy treatment planning aims to deliver a sufficient radiation dose to cancerous tumour cells while sparing healthy organs in the tumour surrounding area. This is a trial and error process highly dependent on the medical staff's experience and knowledge. Case-Based Reasoning (CBR) is an artificial intelligence tool that uses past experiences to solve new problems. A CBR system has been developed to facilitate radiotherapy treatment planning for brain cancer. Given a new patient case the existing CBR system retrieves a similar case from an archive of successfully treated patient cases with the suggested treatment plan. The next step requires adaptation of the retrieved treatment plan to meet the specific demands of the new case. The CBR system was tested by medical physicists for the new patient cases. It was discovered that some of the retrieved cases were not suitable and could not be adapted for the new cases. This motivated us to revise the retrieval mechanism of the existing CBR system by adding a clustering stage that clusters cases based on their tumour positions. A number of well-known clustering methods were investigated and employed in the retrieval mechanism. Results using real world brain cancer patient cases have shown that the success rate of the new CBR retrieval is higher than that of the original system.

  5. Prostate Bed Motion During Intensity-Modulated Radiotherapy Treatment

    SciTech Connect

    Klayton, Tracy; Price, Robert; Buyyounouski, Mark K.; Sobczak, Mark; Greenberg, Richard; Li, Jinsheng; Keller, Lanea; Sopka, Dennis; Kutikov, Alexander; Horwitz, Eric M.

    2012-09-01

    Purpose: Conformal radiation therapy in the postprostatectomy setting requires accurate setup and localization of the prostatic fossa. In this series, we report prostate bed localization and motion characteristics, using data collected from implanted radiofrequency transponders. Methods and Materials: The Calypso four-dimensional localization system uses three implanted radiofrequency transponders for daily target localization and real-time tracking throughout a course of radiation therapy. We reviewed the localization and tracking reports for 20 patients who received ultrasonography-guided placement of Calypso transponders within the prostate bed prior to a course of intensity-modulated radiation therapy at Fox Chase Cancer Center. Results: At localization, prostate bed displacement relative to bony anatomy exceeded 5 mm in 9% of fractions in the anterior-posterior (A-P) direction and 21% of fractions in the superior-inferior (S-I) direction. The three-dimensional vector length from skin marks to Calypso alignment exceeded 1 cm in 24% of all 652 fractions with available setup data. During treatment, the target exceeded the 5-mm tracking limit for at least 30 sec in 11% of all fractions, generally in the A-P or S-I direction. In the A-P direction, target motion was twice as likely to move posteriorly, toward the rectum, than anteriorly. Fifteen percent of all treatments were interrupted for repositioning, and 70% of patients were repositioned at least once during their treatment course. Conclusion: Set-up errors and motion of the prostatic fossa during radiotherapy are nontrivial, leading to potential undertreatment of target and excess normal tissue toxicity if not taken into account during treatment planning. Localization and real-time tracking of the prostate bed via implanted Calypso transponders can be used to improve the accuracy of plan delivery.

  6. Perspectives in Medical Applications of Monte Carlo Simulation Software for Clinical Practice in Radiotherapy Treatments

    NASA Astrophysics Data System (ADS)

    Boschini, Matteo; Giani, Simone; Ivanchenko, Vladimir; Rancoita, Pier-Giorgio

    2006-04-01

    We discuss the physics requirements to accurately model radiation dosimetry in the human body as performed for oncological radiotherapy treatment. Recent advancements in computing hardware and software simulation technology allow precise dose calculation in real-life imaging output, with speed suitable for clinical needs. An experimental programme, based on physics published literature, is proposed to demonstrate the actual possibility to improve the precision of radiotherapy treatment planning.

  7. Short treatment time and excellent treatment outcome in accelerated hyperfractionated radiotherapy for T1 glottic cancer.

    PubMed

    Tamaki, Yukihisa; Hieda, Yoko; Yoshida, Rika; Yoshizako, Takeshi; Fuchiwaki, Takafumi; Aoi, Noriaki; Sekihara, Kazumasa; Kitajima, Kazuhiro; Kawauchi, Hideyuki; Kitagaki, Hajime; Sasaki, Ryohei; Inomata, Taisuke

    2015-11-01

    Accelerated hyperfractionated radiotherapy was performed as treatment for patients with T1 glottic cancer, and its utility was evaluated based on treatment outcomes and adverse effects. Fifty-eight men who had undergone radiotherapy were retrospectively reviewed. Tumor classification was Tis in 4 patients, T1a in 38, and T1b in 16. Histological examination revealed squamous cell carcinoma in 55 patients. Travel time from home to hospital was 0-1 hour for 24 patients, 1-2 hours for 9, and >2 hours for 25. Laser vaporization was performed prior to radiotherapy in 38 patients, and 19 patients received concurrent chemotherapy with an agent such as S-1. Patients were irradiated twice daily using an irradiation container. Most patients received a dose of 1.5 Gy/fraction up to a total of 60 Gy. The median overall treatment time was 30 days, with a median observation period of 59.6 months. A complete response was observed in all patients. The 5-year overall survival, disease-free survival, and local control rates were 97.2%, 93.2%, and 97.8%, respectively. Although grade 3 pharyngeal mucositis was observed in 2 patients, there were no other grade 3 or higher acute adverse events. As late toxicity, grade 2 laryngeal edema and grade 1 laryngeal hemorrhage were observed in 1 patient each, but no serious events such as laryngeal necrosis or laryngeal stenosis were observed. In conclusion, this treatment method brings excellent outcome and will substantially reduce the treatment duration among patients who need to stay at nearby hotels while undergoing treatment at hospitals in rural areas. PMID:26663937

  8. Short treatment time and excellent treatment outcome in accelerated hyperfractionated radiotherapy for T1 glottic cancer

    PubMed Central

    Tamaki, Yukihisa; Hieda, Yoko; Yoshida, Rika; Yoshizako, Takeshi; Fuchiwaki, Takafumi; Aoi, Noriaki; Sekihara, Kazumasa; Kitajima, Kazuhiro; Kawauchi, Hideyuki; Kitagaki, Hajime; Sasaki, Ryohei; Inomata, Taisuke

    2015-01-01

    ABSTRACT Accelerated hyperfractionated radiotherapy was performed as treatment for patients with T1 glottic cancer, and its utility was evaluated based on treatment outcomes and adverse effects. Fifty-eight men who had undergone radiotherapy were retrospectively reviewed. Tumor classification was Tis in 4 patients, T1a in 38, and T1b in 16. Histological examination revealed squamous cell carcinoma in 55 patients. Travel time from home to hospital was 0–1 hour for 24 patients, 1–2 hours for 9, and >2 hours for 25. Laser vaporization was performed prior to radiotherapy in 38 patients, and 19 patients received concurrent chemotherapy with an agent such as S-1. Patients were irradiated twice daily using an irradiation container. Most patients received a dose of 1.5 Gy/fraction up to a total of 60 Gy. The median overall treatment time was 30 days, with a median observation period of 59.6 months. A complete response was observed in all patients. The 5-year overall survival, disease-free survival, and local control rates were 97.2%, 93.2%, and 97.8%, respectively. Although grade 3 pharyngeal mucositis was observed in 2 patients, there were no other grade 3 or higher acute adverse events. As late toxicity, grade 2 laryngeal edema and grade 1 laryngeal hemorrhage were observed in 1 patient each, but no serious events such as laryngeal necrosis or laryngeal stenosis were observed. In conclusion, this treatment method brings excellent outcome and will substantially reduce the treatment duration among patients who need to stay at nearby hotels while undergoing treatment at hospitals in rural areas. PMID:26663937

  9. Role of Radiotherapy as Curative Treatment of Extramammary Paget's Disease

    SciTech Connect

    Hata, Masaharu; Omura, Motoko; Koike, Izumi; Wada, Hidefumi; Miyagi, Etsuko; Tayama, Yoshibumi; Odagiri, Kazumasa; Minagawa, Yumiko; Ogino, Ichiro; Inoue, Tomio

    2011-05-01

    Purpose: Extramammary Paget's disease (EMPD) is a relatively rare malignancy that usually arises in the genital areas. Wide surgical excision remains the standard and most reliable curative treatment of EMPD. However, surgery is sometimes not possible, because many patients are elderly, and complete excision can be difficult owing to the tumor location. We, therefore, performed a review to determine the role of radiotherapy (RT) for EMPD. Methods and Materials: A total of 22 patients with EMPD in their external genitalia (4 men and 18 women, age 52-94 years at RT) underwent RT with curative intent. Nine patients had regional lymph node metastases. A total dose of 45-70.2 Gy (median, 60) was delivered to the pelvis, including the tumors, in 25-39 fractions (median, 33). Results: In all but 3 patients, the irradiated tumors were controlled during a follow-up period of 8-133 months (median, 42). Of the 22 patients, 13 developed recurrences, including local progression within the radiation field in 3 and lymph node and/or distant metastases outside the radiation field in 10, at 3-43 months after treatment. The 2- and 5-year local progression-free rates were 91% and 84%, respectively. Of the 22 patients, 7 patients had died at 33-73 months after RT. The cause of death was tumor progression in 4, infectious pneumonia in 2, and renal failure in 1 patient. The overall and cause-specific survival rates were 100% for both at 2 years and 53% and 73% at 5 years, respectively. No therapy-related Grade 3 or greater toxicity was observed. Conclusions: RT is safe and effective for patients with EMPD. It appears to contribute to prolonged survival as a result of good tumor control.

  10. A client–server framework for 3D remote visualization of radiotherapy treatment space

    PubMed Central

    Santhanam, Anand P.; Min, Yugang; Dou, Tai H.; Kupelian, Patrick; Low, Daniel A.

    2013-01-01

    Radiotherapy is safely employed for treating wide variety of cancers. The radiotherapy workflow includes a precise positioning of the patient in the intended treatment position. While trained radiation therapists conduct patient positioning, consultation is occasionally required from other experts, including the radiation oncologist, dosimetrist, or medical physicist. In many circumstances, including rural clinics and developing countries, this expertise is not immediately available, so the patient positioning concerns of the treating therapists may not get addressed. In this paper, we present a framework to enable remotely located experts to virtually collaborate and be present inside the 3D treatment room when necessary. A multi-3D camera framework was used for acquiring the 3D treatment space. A client–server framework enabled the acquired 3D treatment room to be visualized in real-time. The computational tasks that would normally occur on the client side were offloaded to the server side to enable hardware flexibility on the client side. On the server side, a client specific real-time stereo rendering of the 3D treatment room was employed using a scalable multi graphics processing units (GPU) system. The rendered 3D images were then encoded using a GPU-based H.264 encoding for streaming. Results showed that for a stereo image size of 1280 × 960 pixels, experts with high-speed gigabit Ethernet connectivity were able to visualize the treatment space at approximately 81 frames per second. For experts remotely located and using a 100 Mbps network, the treatment space visualization occurred at 8–40 frames per second depending upon the network bandwidth. This work demonstrated the feasibility of remote real-time stereoscopic patient setup visualization, enabling expansion of high quality radiation therapy into challenging environments. PMID:23440605

  11. 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.

  12. [Development of an educational program starting from a process approach in a department of radiotherapy].

    PubMed

    Lenaerts, E; Delgaudine, M; Coucke, P

    2014-01-01

    In order to be able to implement technological evolution and organizational changes on a regular and continuous manner, the radiotherapy department initiated in 2007 a comprehensive policy of operational risk management and overall quality program. The leadership in the department is convinced that the management of professional skills is mandatory to implement rapidly new treatment techniques while simultaneously assuring a high level of quality for patient care. The "process approach" is based on a comprehensive description of all the processes building up the organization in order to check how every single process contributes to patient satisfaction. This kind of approach allows an enhanced visibility on the functioning of the department, a better control on the inter-individual relations, both between different professional groups among caregivers and between those latter and the patients. This approach yields a view on the gain obtained with each single process and leads to identification of failures in safety barriers. The process approach identifies the required professional skills in order to guarantee a high quality of care. This has resulted in the development of a training program tailored to the needs of a radiotherapy department. This training program has recently been submitted and validated by the university authorities and is nowadays registered as a certificate at the university of Liège. PMID:24822315

  13. Quality assurance of radiotherapy in cancer treatment: toward improvement of patient safety and quality of care.

    PubMed

    Ishikura, Satoshi

    2008-11-01

    The process of radiotherapy (RT) is complex and involves understanding of the principles of medical physics, radiobiology, radiation safety, dosimetry, radiation treatment planning, simulation and interaction of radiation with other treatment modalities. Each step in the integrated process of RT needs quality control and quality assurance (QA) to prevent errors and to give high confidence that patients will receive the prescribed treatment correctly. Recent advances in RT, including intensity-modulated and image-guided RT, focus on the need for a systematic RTQA program that balances patient safety and quality with available resources. It is necessary to develop more formal error mitigation and process analysis methods, such as failure mode and effect analysis, to focus available QA resources optimally on process components. External audit programs are also effective. The International Atomic Energy Agency has operated both an on-site and off-site postal dosimetry audit to improve practice and to assure the dose from RT equipment. Several countries have adopted a similar approach for national clinical auditing. In addition, clinical trial QA has a significant role in enhancing the quality of care. The Advanced Technology Consortium has pioneered the development of an infrastructure and QA method for advanced technology clinical trials, including credentialing and individual case review. These activities have an impact not only on the treatment received by patients enrolled in clinical trials, but also on the quality of treatment administered to all patients treated in each institution, and have been adopted globally; by the USA, Europe and Japan also. PMID:18952706

  14. The primary treatment of advanced vocal cord cancer: laryngectomy or radiotherapy

    SciTech Connect

    van den Bogaert, W.; Ostyn, F.; van der Schueren, E.

    1983-03-01

    When different treatment modalities yield equal results in cancer treatment, the least mutilating is preferred. If results are different, however, the survival rate after treatment must be weighed against the quality of life. Considerable controversy exists concerning the primary treatment modality for advanced glottic cancer, with some authors defending surgery (with or without radiotherapy) and others defending radiotherapy as sole treatment, with laryngectomy reserved for local failures. From a group of 102 patients with T3 and T4 tumors, 65 were treated with a laryngectomy. Uncorrected survival at 5 years was 48%, local control was 75%. A group of 35 patients were treated with radiotherapy. Survival was 22% at 5 years, local control 23%, with rescue surgery 37%. These unfavorable results are related to the negative selection of patients for radiotherapy (inoperable, bad cooperation). In 14 patients who were operable but refused laryngectomy the final local control was 53%, with voice preservation in 34%; survival, however, remained low (27% at 5 years). Primary surgery seems to provide better chances for ultimate survival than radiotherapy alone. At the moment, it is not yet clear if a proportion of patients can be selected for whom a more conservative attitude can be allowed, with laryngectomy reserved for poor regression or recurrences after radiotherapy.

  15. Carbon wastewater treatment process

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; Simmons, G. M.; Dowler, W. L.

    1974-01-01

    A new powdered-carbon treatment process is being developed for the elimination of the present problems, associated with the disposal of biologically active sewage waste solids, and with water reuse. This counter-current flow process produces an activated carbon, which is obtained from the pyrolysis of the sewage solids, and utilizes this material to remove the adulterating materials from the water. Additional advantages of the process are the elimination of odors, the removal of heavy metals, and the potential for energy conservation.

  16. Conformal Radiotherapy in the Treatment of Advanced Juvenile Nasopharyngeal Angiofibroma With Intracranial Extension: An Institutional Experience

    SciTech Connect

    Chakraborty, Santam; Ghoshal, Sushmita; Patil, Vijay Maruti; Oinam, Arun Singh; Sharma, Suresh C.

    2011-08-01

    Purpose: To describe the results of conformal radiotherapy in advanced juvenile nasopharyngeal angiofibroma in a tertiary care institution. Methods and Materials: Retrospective chart review was conducted for 8 patients treated with conformal radiotherapy between 2006 and 2009. The median follow-up was 17 months. All patients had Stage IIIB disease with intracranial extension. Radiotherapy was considered as treatment because patients were deemed inoperable owing to extensive intracranial/intraorbital extension or proximity to optic nerve. All but 1 patient were treated with intensity-modulated radiotherapy using seven coplanar fields. Median (range) dose prescribed was 39.6 (30-46) Gy. Actuarial analysis of local control and descriptive analysis of toxicity profile was conducted. Results: Despite the large and complex target volume (median planning target volume, 292 cm{sup 3}), intensity-modulated radiotherapy achieved conformal dose distributions (median van't Reit index, 0.66). Significant sparing of the surrounding organs at risk was obtained. No significant Grade 3/4 toxicities were experienced during or after treatment. Actual local control at 2 years was 87.5%. One patient died 1 month after radiotherapy secondary to massive epistaxis. The remaining 7 patients had progressive resolution of disease and were symptom-free at last follow-up. Persistent rhinitis was the only significant toxicity, seen in 1 patient. Conclusions: Conformal radiotherapy results in good local control with minimal acute and late side effects in juvenile nasopharyngeal angiofibromas, even in the presence of advanced disease.

  17. Movie making as a cognitive distraction for paediatric patients receiving radiotherapy treatment: qualitative interview study

    PubMed Central

    Shrimpton, Bradley J M; Willis, David J; Tongs, Cáthal D; Rolfo, Aldo G

    2013-01-01

    Objectives To establish the outcomes achieved by using an innovative movie-making programme designed to reduce fear of radiotherapy among paediatric patients. Design Qualitative descriptive evaluation based on semistructured, qualitative interviews with purposeful sampling and thematic analysis. Setting Tertiary Cancer Centre. Participants 20 parents of paediatric patients who had produced a movie of their radiation therapy experience and were in a follow-up phase of cancer management. Results Participants attributed a broad range of outcomes to the movie-making program. These included that the programme had helped reduce anxiety and distress exhibited by paediatric patients and contributed to a willingness to receive treatment. Other outcomes were that the completed movies had been used in school reintegration and for maintaining social connections. Conclusions Allowing children to create a video of their experience of radiotherapy provided a range of benefits to paediatric patients that varied according to their needs. For some patients, movie-making offered a valuable medium for overcoming fear of the unknown as well as increasing understanding of treatment processes. For others, the development of a personalised video offered an important cognitive/attentional distraction through engaging with an age-appropriate activity. Together these outcomes helped children maintain self-control and a positive outlook. PMID:23328308

  18. Stereotactic Body Radiotherapy for Treatment of Adrenal Metastases

    SciTech Connect

    Chawla, Sheema; Chen, Yuhchyau; Katz, Alan W.; Muhs, Ann G.; Philip, Abraham; Okunieff, Paul; Milano, Michael T.

    2009-09-01

    Purpose: To investigate the dosimetry and outcomes of patients undergoing stereotactic body radiotherapy (SBRT) for metastases to the adrenal glands. Methods and Materials: At University of Rochester, patients have been undergoing SBRT for limited metastases since 2001. We retrospectively reviewed 30 patients who had undergone SBRT for adrenal metastases from various primary sites, including lung (n = 20), liver (n = 3), breast (n = 3), melanoma (n = 1), pancreas (n = 1), head and neck (n = 1), and unknown primary (n = 1). Results: Of the 30 patients, 14 with five or fewer metastatic lesions (including adrenal) underwent SBRT, with the intent of controlling all known sites of metastatic disease, and 16 underwent SBRT for palliation or prophylactic palliation of bulky adrenal metastases. The prescribed dose ranged from 16 Gy in 4 fractions to 50 Gy in 10 fractions. The median dose was 40 Gy. Of the 30 patients, 24 had >3 months of follow-up with serial computed tomography. Of these 24 patients, 1 achieved a complete response, 15 achieved a partial response, 4 had stable disease, and 4 developed progressive disease. No patient developed symptomatic progression of their adrenal metastases. The 1-year survival, local control, and distant control rate was 44%, 55%, and 13%, respectively. No patient developed Radiation Therapy Oncology Group Grade 2 or greater toxicity. Conclusion: SBRT for adrenal metastases is well tolerated. Most patients developed widespread metastases shortly after treatment. Local control was poor, although this was a patient population selected for adverse risk factors, such as bulky disease. Additional studies are needed to determine the efficacy of SBRT for oligometastatic adrenal metastases, given the propensity of these patients to develop further disease progression.

  19. A review of recently published radiotherapy treatment guidelines for bone metastases: Contrasts or convergence?

    PubMed Central

    Lutz, Stephen; Chow, Edward

    2012-01-01

    Bone metastases are a common manifestation of malignancy, and external beam radiotherapy (EBRT) effectively and safely palliates the pain caused by this clinical circumstance. The myriad of EBRT dosing schemes and complexities involved with coordinating radiotherapy with other interventions necessitated the need for bone metastases treatment guidelines. Here we compare and contrast the bone metastases radiotherapy treatment guidelines recently published by the American Society for Radiation Oncology (ASTRO) and the American College of Radiology (ACR). These evaluations acknowledge current controversies in treatment approaches, they evaluate the nuances of ASTRO and ACR task force decision-making regarding standard approaches to care, and they project the upcoming research results that may clarify approaches to palliative radiotherapy for bone metastases. The results of these two dedicated radiotherapy guidelines are compared to the brief mentions of radiotherapy for bone metastases in the National Comprehensive Cancer Network (NCCN) guidelines. Finally, the paper describes how treatment guidelines may influence patterns of care and reimbursement by their use as quality measures by groups such as the National Quality Forum (NQF). PMID:26909250

  20. 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

  1. Supervoltage radiotherapy in the treatment of difficult giant cell tumors of bone

    SciTech Connect

    Bell, R.S.; Harwood, A.R.; Goodman, S.B.; Fornasier, V.L.

    1983-04-01

    Fifteen patients with giant cell tumor were treated by supervoltage radiotherapy. Each patient had been referred for therapy because adequate surgery would have been difficult or disfiguring. No patient who received appropriate therapy experienced a recurrence, and there were no cases of malignant transformation of a giant cell tumor after a mean follow-up period of 12 years. Radiotherapy is not recommended for primary treatment of giant cell tumor but may be indicated in exceptional circumstances.

  2. 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

  3. Treatment of Breast and Prostate Cancer by Hypofractionated Radiotherapy: Potential Risks and Benefits.

    PubMed

    Ray, K J; Sibson, N R; Kiltie, A E

    2015-07-01

    Breast cancer and prostate cancer are the most common cancers diagnosed in women and men, respectively, in the UK, and radiotherapy is used extensively in the treatment of both. In vitro data suggest that tumours in the breast and prostate have unique properties that make a hypofractionated radiotherapy treatment schedule advantageous in terms of therapeutic index. Many clinical trials of hypofractionated radiotherapy treatment schedules have been completed to establish the extent to which hypofractionation can improve patient outcome. Here we present a concise description of hypofractionation, the mathematical description of converting between conventional and hypofractionated schedules, and the motivation for using hypofractionation in the treatment of breast and prostate cancer. Furthermore, we summarise the results of important recent hypofractionation trials and highlight the limitations of a hypofractionated treatment regimen. PMID:25752244

  4. Treatment of Breast and Prostate Cancer by Hypofractionated Radiotherapy: Potential Risks and Benefits

    PubMed Central

    Ray, K.J.; Sibson, N.R.; Kiltie, A.E.

    2015-01-01

    Breast cancer and prostate cancer are the most common cancers diagnosed in women and men, respectively, in the UK, and radiotherapy is used extensively in the treatment of both. In vitro data suggest that tumours in the breast and prostate have unique properties that make a hypofractionated radiotherapy treatment schedule advantageous in terms of therapeutic index. Many clinical trials of hypofractionated radiotherapy treatment schedules have been completed to establish the extent to which hypofractionation can improve patient outcome. Here we present a concise description of hypofractionation, the mathematical description of converting between conventional and hypofractionated schedules, and the motivation for using hypofractionation in the treatment of breast and prostate cancer. Furthermore, we summarise the results of important recent hypofractionation trials and highlight the limitations of a hypofractionated treatment regimen. PMID:25752244

  5. Adjuvant Radiotherapy for Gastric Cancer: A Dosimetric Comparison of 3-Dimensional Conformal Radiotherapy, Tomotherapy (registered) and Conventional Intensity Modulated Radiotherapy Treatment Plans

    SciTech Connect

    Dahele, Max; Skinner, Matthew; Schultz, Brenda; Cardoso, Marlene; Bell, Chris; Ung, Yee C.

    2010-07-01

    Some patients with gastric cancer benefit from post-operative chemo-radiotherapy, but adequately irradiating the planning target volume (PTV) whilst avoiding organs at risk (OAR) can be difficult. We evaluate 3-dimensional conformal radiotherapy (CRT), conventional intensity-modulated radiotherapy (IMRT) and helical tomotherapy (TT). TT, 2 and 5-field (F) CRT and IMRT treatment plans with the same PTV coverage were generated for 5 patients and compared. Median values are reported. The volume of left/right kidney receiving at least 20Gy (V20) was 57/51% and 51/60% for 2 and 5F-CRT, and 28/14% for TT and 27/19% for IMRT. The volume of liver receiving at least 30Gy (V30) was 45% and 62% for 2 and 5F-CRT, and 37% for TT and 35% for IMRT. With TT, 98% of the PTV received 95-105% of the prescribed dose, compared with 45%, 34% and 28% for 2F-CRT, 5F-CRT and IMRT respectively. Using conventional metrics, conventional IMRT can achieve comparable PTV coverage and OAR sparing to TT, but at the expense of PTV dose heterogeneity. Both irradiate large volumes of normal tissue to low doses. Additional studies are needed to demonstrate the clinical impact of these technologies.

  6. How Does Intensity-Modulated Radiotherapy Versus Conventional Two-Dimensional Radiotherapy Influence the Treatment Results in Nasopharyngeal Carcinoma Patients?

    SciTech Connect

    Lai Shuzhen; Li Wenfei; Chen Lei; Luo Wei; Chen Yuanyuan; Liu Lizhi; Sun Ying; Lin Aihua; Liu Mengzhong; Ma Jun

    2011-07-01

    Purpose: To compare the results of intensity-modulated radiotherapy (IMRT) with those of two-dimensional conventional radiotherapy (2D-CRT) in the treatment of patients with nasopharyngeal carcinoma (NPC). Methods and Materials: A retrospective review of data from 1,276 patients with biopsy-proven, nonmetastatic NPC was performed. All patients had undergone magnetic resonance imaging and were staged according to the sixth edition of the American Joint Committee on Cancer staging criteria. Radiotherapy was the primary treatment for all patients. Results: Of the 1,276 patients, 512 were treated with IMRT and 764 with 2D-CRT. The 5-year actuarial local relapse-free survival (LRFS), the nodal relapse-free survival (NRFS), the distant metastasis-free survival (DMFS), and the disease-free survival (DFS) rates were 92.7%, 97.0%, 84.0%, and 75.9%, respectively, for the IMRT group, and 86.8%, 95.5%, 82.6%, and 71.4%, respectively, for the 2D-CRT group. In stage T1 patients, improvement of LRFS in the IMRT group was even significantly higher than in the 2D-CRT group (100% vs. 94.4%; p = 0.016). A trend of improvement of DFS was observed in the IMRT group compared with the 2D-CRT group but without reaching statistical significance. NRFS and DMFS rates were similar in the two groups. Conclusions: A greater improvement of treatment results with IMRT than with 2D-CRT was demonstrated primarily by achieving a higher local tumor control rate in NPC patients, especially in the early T stage patients. The goal of better control of both local failure in advanced, nonmetastatic NPC patients and of distant failure should be addressed in future studies.

  7. A multicriteria framework with voxel-dependent parameters for radiotherapy treatment plan optimization

    SciTech Connect

    Zarepisheh, Masoud; Uribe-Sanchez, Andres F.; Li, Nan; Jia, Xun; Jiang, Steve B.

    2014-04-15

    Purpose: To establish a new mathematical framework for radiotherapy treatment optimization with voxel-dependent optimization parameters. Methods: In the treatment plan optimization problem for radiotherapy, a clinically acceptable plan is usually generated by an optimization process with weighting factors or reference doses adjusted for a set of the objective functions associated to the organs. Recent discoveries indicate that adjusting parameters associated with each voxel may lead to better plan quality. However, it is still unclear regarding the mathematical reasons behind it. Furthermore, questions about the objective function selection and parameter adjustment to assure Pareto optimality as well as the relationship between the optimal solutions obtained from the organ-based and voxel-based models remain unanswered. To answer these questions, the authors establish in this work a new mathematical framework equipped with two theorems. Results: The new framework clarifies the different consequences of adjusting organ-dependent and voxel-dependent parameters for the treatment plan optimization of radiation therapy, as well as the impact of using different objective functions on plan qualities and Pareto surfaces. The main discoveries are threefold: (1) While in the organ-based model the selection of the objective function has an impact on the quality of the optimized plans, this is no longer an issue for the voxel-based model since the Pareto surface is independent of the objective function selection and the entire Pareto surface could be generated as long as the objective function satisfies certain mathematical conditions; (2) All Pareto solutions generated by the organ-based model with different objective functions are parts of a unique Pareto surface generated by the voxel-based model with any appropriate objective function; (3) A much larger Pareto surface is explored by adjusting voxel-dependent parameters than by adjusting organ-dependent parameters, possibly

  8. Application of failure mode and effects analysis to treatment planning in scanned proton beam radiotherapy

    PubMed Central

    2013-01-01

    Background A multidisciplinary and multi-institutional working group applied the Failure Mode and Effects Analysis (FMEA) approach to the actively scanned proton beam radiotherapy process implemented at CNAO (Centro Nazionale di Adroterapia Oncologica), aiming at preventing accidental exposures to the patient. Methods FMEA was applied to the treatment planning stage and consisted of three steps: i) identification of the involved sub-processes; ii) identification and ranking of the potential failure modes, together with their causes and effects, using the risk probability number (RPN) scoring system, iii) identification of additional safety measures to be proposed for process quality and safety improvement. RPN upper threshold for little concern of risk was set at 125. Results Thirty-four sub-processes were identified, twenty-two of them were judged to be potentially prone to one or more failure modes. A total of forty-four failure modes were recognized, 52% of them characterized by an RPN score equal to 80 or higher. The threshold of 125 for RPN was exceeded in five cases only. The most critical sub-process appeared related to the delineation and correction of artefacts in planning CT data. Failures associated to that sub-process were inaccurate delineation of the artefacts and incorrect proton stopping power assignment to body regions. Other significant failure modes consisted of an outdated representation of the patient anatomy, an improper selection of beam direction and of the physical beam model or dose calculation grid. The main effects of these failures were represented by wrong dose distribution (i.e. deviating from the planned one) delivered to the patient. Additional strategies for risk mitigation, easily and immediately applicable, consisted of a systematic information collection about any known implanted prosthesis directly from each patient and enforcing a short interval time between CT scan and treatment start. Moreover, (i) the investigation of

  9. Feasibility Study of Intensity-Modulated Radiotherapy (IMRT) Treatment Planning Using Brain Functional MRI

    SciTech Connect

    Chang Jenghwa Kowalski, Alex; Hou, Bob; Narayana, Ashwatha

    2008-04-01

    The purpose of this work was to study the feasibility of incorporating functional magnetic resonance imaging (fMRI) information for intensity modulated radiotherapy (IMRT) treatment planning of brain tumors. Three glioma patients were retrospectively replanned for radiotherapy (RT) with additional fMRI information. The fMRI of each patient was acquired using a bilateral finger-tapping paradigm with a gradient echo EPI (Echo Planer Imaging) sequence. The fMRI data were processed using the Analysis of Functional Neuroimaging (AFNI) software package for determining activation volumes, and the volumes were fused with the simulation computed tomography (CT) scan. The actived pixels in left and right primary motor cortexes (PMCs) were contoured as critical structures for IMRT planning. The goal of replanning was to minimize the RT dose to the activation volumes in the PMC regions, while maintaining a similar coverage to the planning target volume (PTV) and keeping critical structures within accepted dose tolerance. Dose-volume histograms of the treatment plans with and without considering the fMRI information were compared. Beam angles adjustment or additional beams were needed for 2 cases to meet the planning criteria. Mean dose to the contralateral and ipsilateral PMC was significantly reduced by 66% and 55%, respectively, for 1 patient. For the other 2 patients, mean dose to contralateral PMC region was lowered by 73% and 69%. In general, IMRT optimization can reduce the RT dose to the PMC regions without compromising the PTV coverage or sparing of other critical organs. In conclusion, it is feasible to incorporate the fMRI information into the RT treatment planning. IMRT planning allows a significant reduction in RT dose to the PMC regions, especially if the region does not lie within the PTV.

  10. Early adjuvant radiotherapy in the treatment of atypical meningioma.

    PubMed

    Jenkinson, Michael D; Waqar, Mueez; Farah, Jibril Osman; Farrell, Michael; Barbagallo, Giuseppe M V; McManus, Robin; Looby, Seamus; Hussey, Deirdre; Fitzpatrick, David; Certo, Francesco; Javadpour, Mohsen

    2016-06-01

    Atypical meningiomas have a greater propensity to recur than benign meningiomas and the benefits of early adjuvant radiotherapy are unclear. Existing studies report conflicting results. This retrospective cohort study evaluated the role of early adjuvant radiotherapy following surgical resection of atypical meningioma. A triple center case-note review of adults with newly-diagnosed atypical meningiomas between 2001 and 2010 was performed. Pathology diagnosis was made according to the World Health Organization classification in use at the time of surgery. Patients with multiple meningiomas, neurofibromatosis type 2 and radiation-induced meningiomas were excluded. Extent of resection was defined as gross total resection (GTR; Simpson Grade I-III) or subtotal resection (STR; Simpson Grade IV-V). Survival analysis was performed using the Kaplan-Meier method. One hundred thirty-three patients were identified with a median age of 62years (range 22-86years) and median follow-up of 57.4months (range 0.1-152.2months). Tumors were mostly located in the convexity (50.4%) or falcine/parasagittal regions (27.1%). GTR (achieved in 85%) was associated with longer progression free survival (PFS) (5year PFS 81.2% versus 40.08%, log-rank=11.117, p=0.001) but not overall survival (OS) (5year OS 76.6% versus 39.7%, log-rank=3.652, p=0.056). Following GTR, early adjuvant radiotherapy was administered to 28.3% of patients and did not influence OS (5year OS 77.0% versus 75.7%, log-rank=0.075, p=0.784) or PFS (5year PFS 82.0% versus 79.3%, log-rank=0.059, p=0.808). Although extent of resection emerged as an important prognostic variable, early adjuvant radiotherapy did not influence outcome following GTR of atypical meningiomas. Prospective randomized controlled trials are planned. PMID:26775147

  11. [Possibilities of stereotactic radiotherapy in the palliative treatment of patients with pancreatic cancer].

    PubMed

    Tkachev, S I; Medvedev, S V; Znatkova, Ya R; Romanov, D S; Nogovitsyn, E A; Bulychkin, P V; Yurieva, T V; Gutnik, R A; Yazhgunovich, I P; Berdnik, A V; Bykova, Yu B; Bazin, I S; Fedoseenko, D I

    2015-01-01

    Morbidity and mortality from pancreatic cancer is steadily increasing. Resectable cases are not more than 20%. Conventional schemes of chemoradiation and radiation therapy are durable over the time, have toxicity and low treatment outcomes. Many foreign authors consider as promising the technique of stereotactic radiotherapy, which is often used in pancreatic cancer and permit achieving high local control. At our institution there has been developed and introduced into clinical practice a method of stereotactic radiotherapy for the palliative treatment of patients with pancreatic cancer, which improved not only the duration but also the quality of life of patients. PMID:26016157

  12. The advantages of three-dimensional conformal radiotherapy for treatment of childhood cancer.

    PubMed

    Smitt, M C; McPeak, E M; Donaldson, S S

    1998-11-01

    Three-dimensional treatment planning with delivery of conformal radiotherapy has been demonstrated to improve tumor targeting and to reduce normal tissue volume exposed in several studies of malignancies in adults. Furthermore, institutional clinical protocols have accomplished escalation of radiation dose with enhanced treatment efficacy and stable to decreased late effects in patients with prostate carcinoma. In the treatment of malignancies in children, there are several aspects of therapy which may be particularly amenable to improvement with three-dimensional treatment planning. First, the occurrence of large, irregular tumor volumes close to critical normal structures is common in solid tumors in children. The acquisition of detailed computerized tomography (CT) images at the time of simulation, along with the use of three-dimensional reconstruction and beam's-eye-view capabilities, should greatly improve tumor targeting and allow more selective blocking of normal structures. In addition, the enhanced sensitivity of developing organs and tissues to radiation in combination with high expectations for overall survival with current treatment programs has resulted in greater awareness of the late effects of treatment. Today, the goal of pediatric radiotherapy is to provide high rates of local tumor control without significant late effects, such as impairment of growth and development and injury to organ function. The use of conformal radiotherapy is likely to be an important advance in realizing this goal. The ability to use novel beam arrangements and to evaluate radiotherapy treatment plans with quantitative tools, such as dose-volume histogram analysis or probabilities of normal tissue complications, should enable the use of treatment programs with a lessened risk of late effects. However, the rarity of pediatric tumors is unlikely to permit a controlled trial of conformal compared to conventional therapy. In this article, we use three case illustrations to

  13. Image-Guided Radiotherapy in Near Real Time With Intensity-Modulated Radiotherapy Megavoltage Treatment Beam Imaging

    SciTech Connect

    Mao Weihua Hsu, Annie; Riaz, Nadeem; Lee, Louis; Wiersma, Rodney; Luxton, Gary; King, Christopher; Xing Lei; Solberg, Timothy

    2009-10-01

    Purpose: To utilize image-guided radiotherapy (IGRT) in near real time by obtaining and evaluating the online positions of implanted fiducials from continuous electronic portal imaging device (EPID) imaging of prostate intensity-modulated radiotherapy (IMRT) delivery. Methods and Materials: Upon initial setup using two orthogonal images, the three-dimensional (3D) positions of all implanted fiducial markers are obtained, and their expected two-dimensional (2D) locations in the beam's-eye-view (BEV) projection are calculated for each treatment field. During IMRT beam delivery, EPID images of the megavoltage treatment beam are acquired in cine mode and subsequently analyzed to locate 2D locations of fiducials in the BEV. Simultaneously, 3D positions are estimated according to the current EPID image, information from the setup portal images, and images acquired at other gantry angles (the completed treatment fields). The measured 2D and 3D positions of each fiducial are compared with their expected 2D and 3D setup positions, respectively. Any displacements larger than a predefined tolerance may cause the treatment system to suspend the beam delivery and direct the therapists to reposition the patient. Results: Phantom studies indicate that the accuracy of 2D BEV and 3D tracking are better than 1 mm and 1.4 mm, respectively. A total of 7330 images from prostate treatments were acquired and analyzed, showing a maximum 2D displacement of 6.7 mm and a maximum 3D displacement of 6.9 mm over 34 fractions. Conclusions: This EPID-based, real-time IGRT method can be implemented on any external beam machine with portal imaging capabilities without purchasing any additional equipment, and there is no extra dose delivered to the patient.

  14. Review of ultrasound image guidance in external beam radiotherapy: I. Treatment planning and inter-fraction motion management.

    PubMed

    Fontanarosa, Davide; van der Meer, Skadi; Bamber, Jeffrey; Harris, Emma; O'Shea, Tuathan; Verhaegen, Frank

    2015-02-01

    In modern radiotherapy, verification of the treatment to ensure the target receives the prescribed dose and normal tissues are optimally spared has become essential. Several forms of image guidance are available for this purpose. The most commonly used forms of image guidance are based on kilovolt or megavolt x-ray imaging. Image guidance can also be performed with non-harmful ultrasound (US) waves. This increasingly used technique has the potential to offer both anatomical and functional information.This review presents an overview of the historical and current use of two-dimensional and three-dimensional US imaging for treatment verification in radiotherapy. The US technology and the implementation in the radiotherapy workflow are described. The use of US guidance in the treatment planning process is discussed. The role of US technology in inter-fraction motion monitoring and management is explained, and clinical studies of applications in areas such as the pelvis, abdomen and breast are reviewed. A companion review paper (O'Shea et al 2015 Phys. Med. Biol. submitted) will extensively discuss the use of US imaging for intra-fraction motion quantification and novel applications of US technology to RT. PMID:25592664

  15. Review of ultrasound image guidance in external beam radiotherapy: I. Treatment planning and inter-fraction motion management

    NASA Astrophysics Data System (ADS)

    Fontanarosa, Davide; van der Meer, Skadi; Bamber, Jeffrey; Harris, Emma; O'Shea, Tuathan; Verhaegen, Frank

    2015-02-01

    In modern radiotherapy, verification of the treatment to ensure the target receives the prescribed dose and normal tissues are optimally spared has become essential. Several forms of image guidance are available for this purpose. The most commonly used forms of image guidance are based on kilovolt or megavolt x-ray imaging. Image guidance can also be performed with non-harmful ultrasound (US) waves. This increasingly used technique has the potential to offer both anatomical and functional information. This review presents an overview of the historical and current use of two-dimensional and three-dimensional US imaging for treatment verification in radiotherapy. The US technology and the implementation in the radiotherapy workflow are described. The use of US guidance in the treatment planning process is discussed. The role of US technology in inter-fraction motion monitoring and management is explained, and clinical studies of applications in areas such as the pelvis, abdomen and breast are reviewed. A companion review paper (O’Shea et al 2015 Phys. Med. Biol. submitted) will extensively discuss the use of US imaging for intra-fraction motion quantification and novel applications of US technology to RT.

  16. Routine EPID in-vivo dosimetry in a reference point for conformal radiotherapy treatments

    NASA Astrophysics Data System (ADS)

    Fidanzio, Andrea; Azario, Luigi; Greco, Francesca; Cilla, Savino; Piermattei, Angelo

    2015-04-01

    In-vivo dosimetry (IVD) in external beam radiotherapy is used to detect major clinically relevant differences between planned and delivered dose. Moreover, a detailed analysis of its results, when routinely reported and discussed by the radiotherapy staff, can limit the likelihood of error transmission to many treatments. A first experience of routine EPID-based IVD in a reference point has been performed in our department for 3D-CRT treatments over a three-year period. More than 14 000 images were acquired and 1287 treatment plans were verified. The IVD checks were obtained three times in the first week and then weekly. Tolerance levels of ±5% for pelvic-abdomen, head-neck and breast irradiations and ±6% for lung treatments were adopted for the in-vivo measured dose per fraction. A statistical analysis of the IVD results was performed grouping the data by: anatomical regions, treatment units, open and wedged fields and gantry angles. About 10% of the checked doses per fraction showed dosimetric discrepancies out of the tolerance levels. The causes of the discrepancies were 70% delivery or planning errors, 20% morphological changes and 10% procedural limitations. 41 cases (3.2%) have required special investigations because their in-vivo doses per fraction, averaged over the first three sessions, were out of the tolerance levels and in 19 cases (1.5%) the deviations gave rise to an intervention. Statistically significant differences of average variations between planned and delivered doses were observed for: (i) 30° wedged 10 MV fields with respect to those of other wedged or open 10 MV fields delivered by two linacs, due to the incorrect TPS implementation of that wedge transmission factor; (ii) anterior-posterior and posterior-anterior beams with respect to the other gantry orientations for one linac, due to the beam attenuation introduced by the treatment couch; (iii) lateral fields with respect to medial fields of breast irradiations for all linacs, due

  17. Postenucleation orbital radiotherapy for the treatment of malignant melanoma of the choroid with extrascleral extension.

    PubMed Central

    Hykin, P G; McCartney, A C; Plowman, P N; Hungerford, J L

    1990-01-01

    The outcome is reported in 17 patients in whom an eye was enucleated for malignant melanoma of the choroid with extrascleral extension and who subsequently underwent adjuvant external beam radiotherapy to the orbit as the primary treatment of the extraocular spread of their tumour. Extrascleral extension was encapsulated in five, non-encapsulated in two, and had been surgically transected at enucleation in 10 cases. All the patients have been followed up from enucleation to the present day. Orbital recurrence occurred in only one patient. The overall actuarial survival rate was 51% at 5 years, 44% at 10, and 33% at 15 years. A low orbital recurrence rate of 6% compares very favourably with published figures for this event after enucleation for melanoma with extrascleral extension but without radiotherapy. Adjuvant orbital radiotherapy may have a place in the treatment of selected cases of extracleral extension of intraocular malignant melanoma. Images PMID:2106340

  18. Cone Beam Computed Tomography-Derived Adaptive Radiotherapy for Radical Treatment of Esophageal Cancer

    SciTech Connect

    Hawkins, Maria A.; Brooks, Corrinne; Hansen, Vibeke N.; Aitken, Alexandra; Tait, Diana M.

    2010-06-01

    Purpose: To investigate the potential for reduction in normal tissue irradiation by creating a patient specific planning target volume (PTV) using cone beam computed tomography (CBCT) imaging acquired in the first week of radiotherapy for patients receiving radical radiotherapy. Methods and materials: Patients receiving radical RT for carcinoma of the esophagus were investigated. The PTV is defined as CTV(tumor, nodes) plus esophagus outlined 3 to 5 cm cranio-caudally and a 1.5-cm circumferential margin is added (clinical plan). Prefraction CBCT are acquired on Days 1 to 4, then weekly. No correction for setup error made. The images are imported into the planning system. The tumor and esophagus for the length of the PTV are contoured on each CBCT and 5 mm margin is added. A composite volume (PTV1) is created using Week 1 composite CBCT volumes. The same process is repeated using CBCT Week 2 to 6 (PTV2). A new plan is created using PTV1 (adaptive plan). The coverage of the 95% isodose of PTV1 is evaluated on PTV2. Dose-volume histograms (DVH) for lungs, heart, and cord for two plans are compared. Results: A total of 139 CBCT for 14 cases were analyzed. For the adaptive plan the coverage of the 95% prescription isodose for PTV1 = 95.6% +- 4% and the PTV2 = 96.8% +- 4.1% (t test, 0.19). Lungs V20 (15.6 Gy vs. 10.2 Gy) and heart mean dose (26.9 Gy vs. 20.7 Gy) were significantly smaller for the adaptive plan. Conclusions: A reduced planning volume can be constructed within the first week of treatment using CBCT. A single plan modification can be performed within the second week of treatment with considerable reduction in organ at risk dose.

  19. Early versus delayed postoperative radiotherapy for treatment of low-grade gliomas

    PubMed Central

    Sarmiento, J Manuel; Venteicher, Andrew S; Patil, Chirag G

    2015-01-01

    Background In most people with low-grade gliomas (LGG), the primary treatment regimen remains a combination of surgery followed by postoperative radiotherapy. However, the optimal timing of radiotherapy is controversial. It is unclear whether to use radiotherapy in the early postoperative period, or whether radiotherapy should be delayed until tumour progression occurs. Objectives To assess the effects of early postoperative radiotherapy versus radiotherapy delayed until tumour progression for low-grade intracranial gliomas in people who had initial biopsy or surgical resection. Search methods We searched up to September 2014 the following electronic databases: the Cochrane Register of Controlled Trials (CENTRAL, Issue 8, 2014), MEDLINE (1948 to Aug week 3, 2014), and EMBASE (1980 to Aug week 3, 2014) to identify trials for inclusion in this Cochrane review. Selection criteria We included randomised controlled trials (RCTs) that compared early versus delayed radiotherapy following biopsy or surgical resection for the treatment of people with newly diagnosed intracranial LGG (astrocytoma, oligodendroglioma, mixed oligoastrocytoma, astroblastoma, xanthoastrocytoma, or ganglioglioma). Radiotherapy may include conformal external beam radiotherapy (EBRT) with linear accelerator or cobalt-60 sources, intensity-modulated radiotherapy (IMRT), or stereotactic radiosurgery (SRS). Data collection and analysis Three review authors independently assessed the trials for inclusion and risk of bias, and extracted study data. We resolved any differences between review authors by discussion. Adverse effects were also extracted from the study report. We performed meta-analyses using a random-effects model with inverse variance weighting. Main results We included one large, multi-institutional, prospective RCT, involving 311 participants; the risk of bias in this study was unclear. This study found that early postoperative radiotherapy is associated with an increase in time to

  20. Squamous-cell carcinoma of the anus: progress in radiotherapy treatment.

    PubMed

    Glynne-Jones, Rob; Tan, David; Hughes, Robert; Hoskin, Peter

    2016-07-01

    Chemoradiotherapy is the standard-of-care treatment of squamous-cell carcinoma of the anus (SCCA), and this has not changed in decades. Radiation doses of 50-60 Gy, as used in many phase III trials, result in substantial late morbidities and fail to control larger and node-positive tumours. Technological advances in radiation therapy are improving patient outcomes and quality of life, and should be applied to patients with SCCA. Modern techniques such as intensity-modulated radiotherapy (IMRT), rotational IMRT, image-guided radiotherapy using cone-beam CT, and stereotactic techniques have enabled smaller margins and highly conformal plans, resulting in decreased radiation doses to the organs at risk and ensuring a shorter overall treatment time. In this Perspectives article, the use of novel approaches to target delineation, optimized radiotherapy techniques, adaptive radiotherapy, dose-escalation with external-beam radiotherapy (EBRT) or brachytherapy, and the potential for modified fractionation are discussed in the context of SCCA. PMID:26813935

  1. Immune system-tumour efficiency ratio as a new oncological index for radiotherapy treatment optimization.

    PubMed

    Sotolongo-Grau, O; Rodríguez-Pérez, D; Santos-Miranda, J A; Sotolongo-Costa, O; Antoranz, J C

    2009-12-01

    A dynamical system model for tumour-immune system interaction together with a method to mimic radiation therapy are proposed. A large population of virtual patients is simulated following an ideal radiation treatment. A characteristic parameter, the immune system-tumor efficiency ratio (ISTER) is introduced. ISTER dependence of treatment success and other features are studied. Radiotherapy treatment dose optimization, following ALARA (As Low As Reasonably Achievable) criterion, as well as a patient classification are drawn from the statistics results. PMID:19584118

  2. [Quality of life after treatment of laryngeal carcinoma: surgery versus radiotherapy].

    PubMed

    Schneider, A; Guidicelli, M; Stöckli, S J

    2000-01-01

    Radiotherapy and surgery for laryngeal cancer achieve comparable results in patient survival. Therefore, the expected quality of life is increasingly influencing the choice of treatment. The aim of this study was to compare the quality of life of patients after surgery or radiotherapy for laryngeal carcinoma. To evaluate quality of life, we used the validated European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and the EORTC Head and Neck module (EORTC QLQ-H&N35). 65 patients who were treated with either radiotherapy or surgery for laryngeal cancer between January 1990 and December 1995, and who were alive and free of tumour in January 1999, were included in this study. In the first group with small tumours (T1/T2), 40 patients were treated by CO2-laser surgery and 16 by primary radiotherapy. In the second group with more advanced tumours (T3/T4), 5 patients underwent total laryngectomy and 4 primary radiotherapy. In the first group there was good global quality of life with no significant difference between the two treatment modalities. Surgically treated patients scored significantly better than the irradiated patients in questions about swallowing of solid food, xerostomia and dental problems. No other significant differences were found: hoarseness in particular was rated equally after both treatments. In the second group there was also good global quality of life with no significant difference between the two treatment modalities. The laryngectomized patients scored equally on questions about voice function, talking on the phone and social behaviour. As far as quality of life is concerned we can recommend both treatment modalities for patients with laryngeal cancer of all stages. PMID:10780067

  3. Mouth Cancer for Clinicians. Part 11: Cancer Treatment (Radiotherapy).

    PubMed

    Kalavrezos, Nicholas; Scully, Crispian

    2016-06-01

    A MEDLINE search early in 2015 revealed more than 250,000 papers on head and neck cancer; over 100,000 on oral cancer; and over 60,000 on mouth cancer. Not all publications contain robust evidence. We endeavour to encapsulate the most important of the latest information and advances now employed in practice, in a form comprehensible to healthcare workers, patients and their carers. This series offers the primary care dental team in particular, an overview of the aetiopathogenesis, prevention, diagnosis and multidisciplinary care of mouth cancer, the functional and psychosocial implications, and minimization of the impact on the quality of life of patient and family. Clinical Relevance: This article offers the dental team an overview of the use of radiotherapy, and its effects on the mouth and other tissues. PMID:27529915

  4. Mechanical and dosimetric quality control for computer controlled radiotherapy treatment equipment.

    PubMed

    Thompson, A V; Lam, K L; Balter, J M; McShan, D L; Martel, M K; Weaver, T A; Fraass, B A; Ten Haken, R K

    1995-05-01

    Modern computer controlled radiotherapy treatment equipment offers the possibility of delivering complex, multiple field treatments with minimal operator intervention, thus making multiple field conformal therapy practical. Conventional quality control programs are inadequate for this new technology, so new quality control procedures are needed. A reasonably fast, sensitive, and complete daily quality control program has been developed in our clinic that includes nearly automated mechanical as well as dosimetric tests. Automated delivery of these quality control fields is performed by the control system of the MM50 racetrack microtron, directed by the CCRS sequence processor [D. L. McShan and B. A. Fraass, Proceedings of the XIth International Conference on the use of computers in Radiation Therapy, 20-24 March 1994, Manchester, U.K. (North Western Medical Physics Department, Manchester, U.K., 1994), pp. 210-211], which controls the treatment process. The mechanical tests involve multiple irradiations of a single film to check the accuracy and reproducibility of the computer controlled setup of gantry and collimator angles, table orientation, collimator jaws, and multileaf collimator shape. The dosimetric tests, which involve multiple irradiations of an array of ionization chambers in a commercial dose detector (Keithly model 90100 Tracker System) rigidly attached to the head of the treatment gantry, check the output and symmetry of the treatment unit as a function of gantry and collimator angle and other parameters. For each of the dosimetric tests, readings from the five ionization chambers are automatically read out, stored, and analyzed by the computer, along with the geometric parameters of the treatment unit for that beam.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7643792

  5. A hybrid virtual environment for training of radiotherapy treatment of cancer

    NASA Astrophysics Data System (ADS)

    Phillips, Roger; Ward, James W.; Bridge, Pete; Appleyard, Rob M.; Beavis, Andrew W.

    2006-02-01

    There is often insufficient access to patients and linear accelerator treatment rooms to train radiotherapy students. An alternative approach is for some training to use a hybrid virtual environment (HVE) that simulates an actual radiotherapy treatment machine controlled with the actual machine's handheld control pendant. A study of training using such a HVE is presented for "skin apposition" treatment, where the patient couch and radiotherapy equipment are positioned so that the radiation beam strikes the skin perpendicularly. The HVE developed comprises a virtual treatment room with a linear accelerator, modelled from laser scan data and a virtual patient. A genuine linear accelerator control handheld "pendant" provided the user interface to the virtual linear accelerator. A virtual patient, based on the visible human female dataset, complete with rectangular markings for a range of different treatment sites, provided a range of treatment scenarios. Students were trained in groups with the virtual world being displayed stereoscopically on a large work-wall. A study of 42 students was conducted to evaluate learning. 93% of students perceived an improvement in their understanding of this treatment using the HVE and 69% found the control system to be easy to master.

  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. Stereotactic Ablative Radiotherapy for the Treatment of Clinically Localized Renal Cell Carcinoma

    PubMed Central

    Campbell, Scott P.; Song, Daniel Y.; Pierorazio, Phillip M.; Allaf, Mohamad E.; Gorin, Michael A.

    2015-01-01

    Thermal ablation is currently the most studied treatment option for medically inoperable patients with clinically localized renal cell carcinoma (RCC). Recent evidence suggests that stereotactic ablative radiotherapy (SABR) may offer an effective noninvasive alternative for these patients. In this review, we explore the current literature on SABR for the primary treatment of RCC and make recommendations for future studies so that an accurate comparison between SABR and other ablative therapies may be conducted. PMID:26640488

  8. Chinese herbal medicines as adjuvant treatment during chemo- or radio-therapy for cancer.

    PubMed

    Qi, Fanghua; Li, Anyuan; Inagaki, Yoshinori; Gao, Jianjun; Li, Jijun; Kokudo, Norihiro; Li, Xiao-Kang; Tang, Wei

    2010-12-01

    Numerous studies have indicated that in cancer treatment Chinese herbal medicines in combination with chemo- or radio-therapy can be used to enhance the efficacy of and diminish the side effects and complications caused by chemo- and radio-therapy. Therefore, an understanding of Chinese herbal medicines is needed by physicians and other health care providers. This review provides evidence for use of Chinese herbal medicines as adjuvant cancer treatment during chemo- or radio-therapy. First, Chinese herbal medicines (e.g. Astragalus, Turmeric, Ginseng, TJ-41, PHY906, Huachansu injection, and Kanglaite injection) that are commonly used by cancer patients for treating the cancer and/or reducing the toxicity induced by chemo- or radio-therapy are discussed. Preclinical and clinical studies have shown that these Chinese herbal medicines possess great advantages in terms of suppressing tumor progression, increasing the sensitivity of chemo- and radio-therapeutics, improving an organism's immune system function, and lessening the damage caused by chemo- and radio-therapeutics. Second, clinical trials of Chinese herbal medicines as adjuvant cancer treatment are reviewed. By reducing side effects and complications during chemo- and radio-therapy, these Chinese herbal medicines have a significant effect on reducing cancer-related fatigue and pain, improving respiratory tract infections and gastrointestinal side effects including diarrhea, nausea, and vomiting, protecting liver function, and even ameliorating the symptoms of cachexia. This review should contribute to an understanding of Chinese herbal medicines as adjuvant treatment for cancer and provide useful information for the development of more effective anti-cancer drugs. PMID:21248427

  9. INNOVATIVE THERMAL TREATMENT PROCESSES

    EPA Science Inventory

    The paper contains discussions of several innovative thermal processes for treating or destroying hazardous wastes. Processes discussed can be included in the categories wet oxidation, molten glass, fluidized bed incineration, pyrolysis, molten salt, electric reactors, and plasma...

  10. Pre-treatment radiotherapy dose verification using Monte Carlo doselet modulation in a spherical phantom

    NASA Astrophysics Data System (ADS)

    Townson, Reid W.; Zavgorodni, Sergei

    2014-04-01

    Due to the increasing complexity of radiotherapy delivery, accurate dose verification has become an essential part of the clinical treatment process. The purpose of this work was to develop a pre-treatment verification technique capable of quickly reconstructing 3D dose distributions from both coplanar and non-coplanar treatments. For each treatment field, electronic portal images were taken in non-transmission mode (with no patient in the beam) allowing the derivation of the delivered fluence maps. The dose reconstruction was then performed in a spherical water phantom by modulating and summing the Monte Carlo (MC) doselets, defined on a spherical co-ordinate system, and pre-calculated from azimuthally symmetric fluence above the jaws. The technique, called the spherical doselet modulation (SDM) method, essentially eliminates the statistical uncertainty of the MC dose calculations by exploiting the azimuthal symmetry in both a patient-independent phase-space and in a virtual spherical water phantom. For example, this symmetry allowed the number of doselets necessary for dose reconstruction to be reduced by a factor of ˜250. In this work, only 51 radially binned doselets were used (each generated from all particles in a given annulus of the phase-space, azimuthally redistributed into a small cylindrical sector). The SDM method mitigates the most computationally intensive part of this type of dose reconstruction--reading, weighting and summing dose matrices. The accuracy of the system was tested against MC calculations as well as our previously reported phase-space modulation method, using a series of open field and IMRT cases. The mean chi- and gamma-test 3%/3 mm success rates of the SDM method were 98.6% and 99.5%, respectively, when compared to full MC simulation. The total calculation time was 96 s per treatment field on a single processor core.

  11. 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

    treatment times and 50% lower number of delivered monitor units (MU) were achievable with CyberKnife-multi-leaf collimator than with CyberKnife-Iris. The CyberKnife-multi-leaf collimator treatment times were comparable to 3-dimensional conformal radiotherapy, however, the number of MU delivered was approximately 2.5 times larger. The suitability of 10 + 2 mm margins warrants further investigation. PMID:26335703

  12. The Development and Evaluation of a Virtual Radiotherapy Treatment Machine Using an Immersive Visualisation Environment

    ERIC Educational Resources Information Center

    Bridge, P.; Appleyard, R. M.; Ward, J. W.; Philips, R.; Beavis, A. W.

    2007-01-01

    Due to the lengthy learning process associated with complicated clinical techniques, undergraduate radiotherapy students can struggle to access sufficient time or patients to gain the level of expertise they require. By developing a hybrid virtual environment with real controls, it was hoped that group learning of these techniques could take place…

  13. Axillary radiotherapy: an alternative treatment option for adjuvant axillary management of breast cancer

    PubMed Central

    Zhang, Jie; Wang, Chuan

    2016-01-01

    Axillary lymph node dissection is standard management of axilla in invasive breast cancer. Radiotherapy also is important in local treatment. It is controversial as to whether axillary radiotherapy can displace axillary lymph node dissection. We performed a meta-analysis comparing axillary radiotherapy with axillary dissection. No significant difference was observed for disease free survival and overall survival between the radiation group and the dissection group. There was also no significant difference in either the axillary recurrence or the local recurrence between the two groups. But the axillary relapse rate in the radiation group was higher than in the surgery group at five-year follow-up while the local recurrence rate in the surgery group was higher than in the radiation group. A subgroup analysis showed that the difference in the axillary recurrence rate (RR = 0.20, P = 0.01) and local recurrence rate (RR = 4.7, P = 0.01) mainly appeared in the clinical node-positive subgroup. The edema rate in the surgery group was higher than in the radiation group (RR = 2.08, 95%: 1.71–2.54, P < 0.0001). We concluded that radiotherapy may be an alternative treatment option for adjuvant management of the axilla in selected sub-groups of patients. PMID:27212421

  14. Treatment of Locally Advanced Adenoid Cystic Carcinoma of the Trachea With Neutron Radiotherapy

    SciTech Connect

    Bittner, Nathan; Koh, W.-J.; Laramore, George E.; Patel, Shilpen; Mulligan, Michael S.; Douglas, James G.

    2008-10-01

    Purpose: To examine the efficacy of fast neutron radiotherapy in the treatment of locally advanced adenoid cystic carcinoma (ACC) of the trachea and to compare outcomes with and without high-dose-rate (HDR) endobronchial brachytherapy boost. Methods and Materials: Between 1989 and 2005, a total of 20 patients with ACC of the trachea were treated with fast neutron radiotherapy at University of Washington. Of these 20 patients, 19 were treated with curative intent. Neutron doses ranged from 10.7 to 19.95 Gy (median, 19.2 Gy). Six of these patients received an endobronchial brachytherapy boost using an HDR {sup 192}Ir source (3.5 Gy x 2 fractions). Median duration of follow-up was 46 months (range, 10-121 months). Results: The 5-year actuarial overall survival rate and median overall survival for the entire cohort were 89.4%, and 97 months, respectively. Overall survival was not statistically different among those patients receiving an endobronchial boost compared with those receiving neutron radiotherapy alone (100% vs. 68%, p = 0.36). The 5-year actuarial locoregional control rate for the entire cohort was 54.1%. The locoregional control rate was not statistically different among patients who received an endobronchial boost compared with those who received neutron radiotherapy alone (40% vs. 58%, p 0.94). There were no cases of Grade {>=}3 acute toxicity. There were 2 cases of Grade 3/4 chronic toxicity. Conclusions: Fast neutron radiotherapy is an effective treatment for locally advanced adenoid cystic carcinoma of the trachea, with acceptable treatment-related toxicity.

  15. Definitive radiotherapy for primary vaginal cancer: correlation between treatment patterns and recurrence rate

    PubMed Central

    Kanayama, Naoyuki; Isohashi, Fumiaki; Yoshioka, Yasuo; Baek, Sungjae; Chatani, Masashi; Kotsuma, Tadayuki; Tanaka, Eiichi; Yoshida, Ken; Seo, Yuji; Suzuki, Osamu; Mabuchi, Seiji; Shiki, Yasuhiko; Tatsumi, Keiji; Kimura, Tadashi; Teshima, Teruki; Ogawa, Kazuhiko

    2015-01-01

    The purpose of this study was to determine the outcomes and optimal practice patterns of definitive radiotherapy for primary vaginal cancer. Between 1993 and 2012, 49 patients were treated with definitive radiotherapy for primary vaginal cancer in three hospitals. Of these, 15 patients (31%) had clinically positive regional lymph node metastasis. A total of 34 patients (70%) received external beam radiotherapy with high-dose-rate brachytherapy (interstitial or intracavitary), and 8 (16%) (with small superficial Stage I tumors) were treated with local radiotherapy. The median follow-up was 33 months (range: 1–169 months). The 3-year overall survival (OS), disease-free survival (DFS), and loco-regional control (LRC) rates were 83%, 59% and 71%, respectively. In multivariate analysis, the histological type (P = 0.044) was significant risk factors for LRC. In Federation of Gynecology and Obstetrics (FIGO) Stage I cases, 3 of 8 patients (38%) who did not undergo prophylactic lymph node irradiation had lymph node recurrence, compared with 2 of 12 patients (17%) who underwent prophylactic pelvic irradiation. For Stage III–IV tumors, the local recurrence rate was 50% and the lymph node recurrence rate was 40%. Patients with FIGO Stage I/II or clinical Stage N1 had a higher recurrence rate with treatment using a single modality compared with the recurrence rate using combined modalities. In conclusion, our treatment outcomes for vaginal cancer were acceptable, but external beam radiotherapy with brachytherapy (interstitial or intracavitary) was needed regardless of FIGO stage. Improvement of treatment outcomes in cases of FIGO Stage III or IV remains a significant challenge. PMID:25614068

  16. Dosimetric Feasibility of Hypofractionated Proton Radiotherapy for Neoadjuvant Pancreatic Cancer Treatment

    SciTech Connect

    Kozak, Kevin R.; Kachnic, Lisa A.; Adams, Judith C; Crowley, Elizabeth M.; Alexander, Brian M.; Mamon, Harvey J.; Ryan, David P.; DeLaney, Thomas F.; Hong, Theodore S. . E-mail: tshong1@partners.org

    2007-08-01

    Purpose: To evaluate tumor and normal tissue dosimetry of a 5 cobalt gray equivalent (CGE) x 5 fraction proton radiotherapy schedule, before initiating a clinical trial of neoadjuvant, short-course proton radiotherapy for pancreatic adenocarcinoma. Methods and Materials: The first 9 pancreatic cancer patients treated with neoadjuvant intensity-modulated radiotherapy (1.8 Gy x 28) at the Massachusetts General Hospital had treatment plans generated using a 5 CGE x 5 fraction proton regimen. To facilitate dosimetric comparisons, clinical target volumes and normal tissue volumes were held constant. Plans were optimized for target volume coverage and normal tissue sparing. Results: Hypofractionated proton and conventionally fractionated intensity-modulated radiotherapy plans both provided acceptable target volume coverage and dose homogeneity. Improved dose conformality provided by the hypofractionated proton regimen resulted in significant sparing of kidneys, liver, and small bowel, evidenced by significant reductions in the mean doses, expressed as percentage prescribed dose, to these structures. Kidney and liver sparing was most evident in low-dose regions ({<=}20% prescribed dose for both kidneys and {<=}60% prescribed dose for liver). Improvements in small-bowel dosimetry were observed in high- and low-dose regions. Mean stomach and duodenum doses, expressed as percentage prescribed dose, were similar for the two techniques. Conclusions: A proton radiotherapy schedule consisting of 5 fractions of 5 CGE as part of neoadjuvant therapy for adenocarcinoma of the pancreas seems dosimetrically feasible, providing excellent target volume coverage, dose homogeneity, and normal tissue sparing. Hypofractionated proton radiotherapy in this setting merits Phase I clinical trial investigation.

  17. [Stereotactic radiotherapy is established treatment in localized non-small cell lung cancer].

    PubMed

    Sailas, Liisa; Virsunen, Heli

    2016-01-01

    Surgery has been the standard treatment in localized non-small cell lung cancer. Some of the early stage lung cancer patients are not suitable for surgery owing to associated diseases or refusing surgery. Ninety percent of untreated patients die within five years. Stereotactic ablative radiotherapy is a technique in which highly focused radiation treatment is given at a couple of high single doses to the tumor region. The treatment results in an average of 90% local control of the cancer, and the adverse effects are minor. Treatment outcome is equivalent to those of surgical therapy and is better than obtained with conventional external radiation therapy. PMID:27132296

  18. Process-based quality management for clinical implementation of adaptive radiotherapy

    PubMed Central

    Noel, Camille E.; Santanam, Lakshmi; Parikh, Parag J.; Mutic, Sasa

    2014-01-01

    Purpose: Intensity-modulated adaptive radiotherapy (ART) has been the focus of considerable research and developmental work due to its potential therapeutic benefits. However, in light of its unique quality assurance (QA) challenges, no one has described a robust framework for its clinical implementation. In fact, recent position papers by ASTRO and AAPM have firmly endorsed pretreatment patient-specific IMRT QA, which limits the feasibility of online ART. The authors aim to address these obstacles by applying failure mode and effects analysis (FMEA) to identify high-priority errors and appropriate risk-mitigation strategies for clinical implementation of intensity-modulated ART. Methods: An experienced team of two clinical medical physicists, one clinical engineer, and one radiation oncologist was assembled to perform a standard FMEA for intensity-modulated ART. A set of 216 potential radiotherapy failures composed by the forthcoming AAPM task group 100 (TG-100) was used as the basis. Of the 216 failures, 127 were identified as most relevant to an ART scheme. Using the associated TG-100 FMEA values as a baseline, the team considered how the likeliness of occurrence (O), outcome severity (S), and likeliness of failure being undetected (D) would change for ART. New risk priority numbers (RPN) were calculated. Failures characterized by RPN ≥ 200 were identified as potentially critical. Results: FMEA revealed that ART RPN increased for 38% (n = 48/127) of potential failures, with 75% (n = 36/48) attributed to failures in the segmentation and treatment planning processes. Forty-three of 127 failures were identified as potentially critical. Risk-mitigation strategies include implementing a suite of quality control and decision support software, specialty QA software/hardware tools, and an increase in specially trained personnel. Conclusions: Results of the FMEA-based risk assessment demonstrate that intensity-modulated ART introduces different (but not necessarily

  19. Process-based quality management for clinical implementation of adaptive radiotherapy

    SciTech Connect

    Noel, Camille E.; Santanam, Lakshmi; Parikh, Parag J.; Mutic, Sasa

    2014-08-15

    Purpose: Intensity-modulated adaptive radiotherapy (ART) has been the focus of considerable research and developmental work due to its potential therapeutic benefits. However, in light of its unique quality assurance (QA) challenges, no one has described a robust framework for its clinical implementation. In fact, recent position papers by ASTRO and AAPM have firmly endorsed pretreatment patient-specific IMRT QA, which limits the feasibility of online ART. The authors aim to address these obstacles by applying failure mode and effects analysis (FMEA) to identify high-priority errors and appropriate risk-mitigation strategies for clinical implementation of intensity-modulated ART. Methods: An experienced team of two clinical medical physicists, one clinical engineer, and one radiation oncologist was assembled to perform a standard FMEA for intensity-modulated ART. A set of 216 potential radiotherapy failures composed by the forthcoming AAPM task group 100 (TG-100) was used as the basis. Of the 216 failures, 127 were identified as most relevant to an ART scheme. Using the associated TG-100 FMEA values as a baseline, the team considered how the likeliness of occurrence (O), outcome severity (S), and likeliness of failure being undetected (D) would change for ART. New risk priority numbers (RPN) were calculated. Failures characterized by RPN ≥ 200 were identified as potentially critical. Results: FMEA revealed that ART RPN increased for 38% (n = 48/127) of potential failures, with 75% (n = 36/48) attributed to failures in the segmentation and treatment planning processes. Forty-three of 127 failures were identified as potentially critical. Risk-mitigation strategies include implementing a suite of quality control and decision support software, specialty QA software/hardware tools, and an increase in specially trained personnel. Conclusions: Results of the FMEA-based risk assessment demonstrate that intensity-modulated ART introduces different (but not necessarily

  20. Radiotherapy of brain metastases from breast cancer: Treatment results and prognostic factors

    PubMed Central

    KÜHNÖL, JULIA; KÜHNÖL, CASPAR; VORDERMARK, DIRK

    2016-01-01

    Brain metastases (BM) from breast cancer are associated with high morbidity and a poor prognosis. The aim of this study was to analyse the role of radiotherapy in treatment of BM from breast cancer in the context of modern local therapy modalities, current systemic treatment options and prognostic factors. A retrospective analysis of 86 consecutive female patients treated with radiotherapy for BM from breast cancer between 2000 and 2010 was conducted. Patient and treatment characteristics were registered and survival data calculated. All patients received whole-brain radiotherapy (WBRT) with a median dose of 36 Gy, and 19 patients were treated with an additional boost; this included fractionated schemes (median dose, 18 Gy) and radiosurgery (5 and 17 Gy). The median overall survival time from the start of WBRT was 4.1 months in the present cohort. Patients receiving a boost survived 19.7 months in comparison to 3.1 months for patients treated with WBRT alone (P<0.001). Other factors that improved overall survival, based on a univariate analysis, were dose of WBRT and number of BM. There was no statistical evidence for the influence of the human epidermal growth factor receptor 2 status on survival in the current study. The administration of boost treatment following WBRT was also identified as a significant factor influencing survival on multivariate analysis (P=0.030). In conclusion, radiotherapy affects the survival time of patients with BM from breast cancer. In particular, the implementation of boost treatment following WBRT in selected patients seems to extend survival time. PMID:27123095

  1. Powder treatment process

    DOEpatents

    Weyand, J.D.

    1988-02-09

    Disclosed are: (1) a process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder. 2 figs.

  2. Powder treatment process

    DOEpatents

    Weyand, John D.

    1988-01-01

    (1) A process comprising spray drying a powder-containing slurry, the slurry containing a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, while reducing the tendency for oxidation of the constituent by including as a liquid constituent of the slurry an organic liquid; (2) a process comprising spray drying a powder-containing slurry, the powder having been pretreated to reduce content of a powder constituent susceptible of oxidizing under the temperature conditions of the spray drying, the pretreating comprising heating the powder to react the constituent; and (3) a process comprising reacting ceramic powder, grinding the reacted powder, slurrying the ground powder, spray drying the slurried powder, and blending the dried powder with metal powder.

  3. Automated Extraction of Dose/Volume Statistics for Radiotherapy-Treatment-Plan Evaluation in Clinical-Trial Quality Assurance

    PubMed Central

    Gong, Yutao U. T.; Yu, Jialu; Pang, Dalong; Zhen, Heming; Galvin, James; Xiao, Ying

    2016-01-01

    Radiotherapy clinical-trial quality assurance is a crucial yet challenging process. This note presents a tool that automatically extracts dose/volume statistics for determining dosimetry compliance review with improved efficiency and accuracy. A major objective of this study is to develop an automated solution for clinical-trial radiotherapy dosimetry review. PMID:26973814

  4. Long-term results of fractionated stereotactic radiotherapy as third-line treatment in acromegaly.

    PubMed

    Diallo, Alpha M; Colin, Philippe; Litre, Claude F; Diallo, Mamadou M; Decoudier, Bénédicte; Bertoin, Florence; Higel, Brigitte; Patey, Martine; Rousseaux, Pascal; Delemer, Brigitte

    2015-12-01

    The treatment of acromegaly is based on surgery, drugs, and radiotherapy as a third-line option. Fractionated stereotactic radiotherapy (FSRT) is a new technique with a need for long-term evaluation. The purpose of the study was to evaluate long-term results of FSRT in acromegaly. Overall, 34 patients [sex ratio 1.12, age 45 (5-65) years] with a pituitary adenoma of 24.5 (9-76) mm including 20 invasive tumors were treated by radiotherapy in fractionated stereotactic conditions delivering 50 gy in 27 sessions. Baseline growth hormone (GH) and IGF1 levels were 18 (±14.5) and 632.6 (±339) µg/L, respectively. Indications of FSRT were failure of surgery and drug treatments (n = 30) or contraindication/refusal of surgery (n = 4). Hormonal control was defined by normal age- and sex-adjusted IGF1. Remission was defined by hormonal control after withdrawal of drugs for a minimum of three consecutive months. Data were analyzed in SPSS software with a significance level at p < 0.05. After a mean follow-up of 152 months, hormonal control was achieved in 33 patients (97 %) with withdrawal of drugs in 13 patients (38.2 %) without any recurrence. Factors found to be significantly associated to remission in a multivariate Cox regression were lower baseline hormone levels (GH and IGF1) and smaller tumor size. Tumor control was achieved in all patients. Acquired hypopituitarism after radiotherapy was the main side effect reported with a rate of 39 %. FSRT seems to be an effective and well tolerated third-line treatment of acromegaly, particularly adapted to macro adenomas treatment. PMID:25956280

  5. SU-E-T-148: Efficient Verification Method for Modulated Electron Radiotherapy Treatment Plans

    SciTech Connect

    Henzen, D; Chatelain, C; Manser, P; Frei, D; Volken, W; Joosten, A; Loessl, K; Aebersold, D M; Fix, M K; Neuenschwander, H

    2014-06-01

    Purpose: For shallow tumors, modulated electron radiotherapy (MERT) promises a reduction of dose to distal organs at risk. At our institution a framework was developed in order to create treatment plans for MERT employing both forward and inverse optimization. In this work, an efficient quality assurance (QA) process is established. Methods: Treatment plans for three different tumor sites were created using an inverse optimization. These plans consist of 6–12 segments and energies between 6 and 18 MeV. An already established QA process for photon IMRT plans is now extended to additionally handle MERT plans. First, the dose distributions are calculated in a homogenous water phantom. For this task a dedicated Monte Carlo (MC) framework for MERT is used. Second, the segments are applied on a stand-alone amorphous silicon electronic portal imaging device (EPID) using a source-to-surface distance of 70 cm. This device was calibrated for electron beams in a previous work. An in-house developed analysis software, is then utilized for comparisons and evaluation of the measured and calculated dose distributions. Results: For all three plans the calculated dose distributions agree well with the measured ones. Using a 2D gamma comparison (2% of dose max/2 mm and 10% dose threshold) passing rates >98% are achieved.The dose calculation for each plan on the water phantom, using voxels of 0.2×0.2×0.2 cm{sup 3}, takes at maximum 30 min on a single core Pentium 2.66 GHz system with 6 GB RAM, to reach a statistical uncertainty of 2% (1 std. dev.). Conclusion: An already established QA procedure for IMRT photon plans was applied for MERT. The dedicated MC framework and the use of EPID measurements allow an efficient QA procedure in a clinical environment. This work was supported by Varian Medical Systems.

  6. Evaluation of the radiotherapy treatment planning in the presence of a magnetic valve tissue expander.

    PubMed

    Trombetta, Débora M; Cardoso, Simone C; Alves, Victor G L; Facure, Alessandro; Batista, Delano V S; da Silva, Ademir X

    2015-01-01

    The combination of radiotherapy treatments and breast reconstruction, using temporary tissue expanders, generates several concerns due to the presence of a magnetic valve inside the radiation field. The objective of this work is to evaluate a radiotherapy treatment planning for a patient using a tissue expander. Isodose curve maps, obtained using radiochromic films, were compared to the ones calculated with two different dose calculation algorithms of the Eclipse radiotherapy Treatment Planning System (TPS), considering the presence or absence of the heterogeneity. The TPS calculation considering the presence of the heterogeneity shows changes around 5% in the isodose curves when they were compared with the calculation without heterogeneity correction. This calculation did not take in account the real density value of the heterogeneity. This limitation was quantified to be around 10% in comparison with the TPS calculation and experimental measurements using the radiochromic film. These results show that the magnetic valve should be taken in account in dose calculations of the TPS. With respect to the AAA and Pencil Beam Convolution algorithms, when the calculation is compared with the real distribution, AAA presents a distribution more similar to experimental dose distribution. PMID:25679529

  7. Pictorial review. Magnetic resonance for radiotherapy management and treatment planning in prostatic carcinoma.

    PubMed

    Lim, Christopher; Malone, Shawn C; Avruch, Leonard; Breau, Rodney H; Flood, Trevor A; Lim, Megan; Morash, Christopher; Quon, Jeff S; Walsh, Cynthia; Schieda, Nicola

    2015-10-01

    MRI has an important role for radiotherapy (RT) treatment planning in prostate cancer (PCa) providing accurate visualization of the dominant intraprostatic lesion (DIL) and locoregional anatomy, assessment of local staging and depiction of implanted devices. MRI enables the radiation oncologist to optimize RT planning by better defining target tumour volumes (thereby increasing local tumour control), as well as decreasing morbidity (by minimizing the dose to adjacent normal structures). Using MRI, radiation oncologists can define the DIL for delivery of boost doses of RT using a variety of techniques including: stereotactic body radiotherapy, intensity-modulated radiotherapy, proton RT or brachytherapy to improve tumour control. Radiologists require a familiarity with the different RT methods used to treat PCa, as well as an understanding of the advantages and disadvantages of the various MR pulse sequences available for RT planning in order to provide an optimal multidisciplinary RT treatment approach to PCa. Understanding the expected post-RT appearance of the prostate and typical characteristics of local tumour recurrence is also important because MRI is rapidly becoming an integral component for diagnosis, image-guided histological sampling and treatment planning in the setting of biochemical failure after RT or surgery. PMID:26279086

  8. Evaluation of the Radiotherapy Treatment Planning in the Presence of a Magnetic Valve Tissue Expander

    PubMed Central

    Trombetta, Débora M.; Cardoso, Simone C.; Alves, Victor G. L.; Facure, Alessandro; Batista, Delano V. S.; da Silva, Ademir X.

    2015-01-01

    The combination of radiotherapy treatments and breast reconstruction, using temporary tissue expanders, generates several concerns due to the presence of a magnetic valve inside the radiation field. The objective of this work is to evaluate a radiotherapy treatment planning for a patient using a tissue expander. Isodose curve maps, obtained using radiochromic films, were compared to the ones calculated with two different dose calculation algorithms of the Eclipse radiotherapy Treatment Planning System (TPS), considering the presence or absence of the heterogeneity. The TPS calculation considering the presence of the heterogeneity shows changes around 5% in the isodose curves when they were compared with the calculation without heterogeneity correction. This calculation did not take in account the real density value of the heterogeneity. This limitation was quantified to be around 10% in comparison with the TPS calculation and experimental measurements using the radiochromic film. These results show that the magnetic valve should be taken in account in dose calculations of the TPS. With respect to the AAA and Pencil Beam Convolution algorithms, when the calculation is compared with the real distribution, AAA presents a distribution more similar to experimental dose distribution. PMID:25679529

  9. American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: quality assurance for clinical radiotherapy treatment planning.

    PubMed

    Fraass, B; Doppke, K; Hunt, M; Kutcher, G; Starkschall, G; Stern, R; Van Dyke, J

    1998-10-01

    In recent years, the sophistication and complexity of clinical treatment planning and treatment planning systems has increased significantly, particularly including three-dimensional (3D) treatment planning systems, and the use of conformal treatment planning and delivery techniques. This has led to the need for a comprehensive set of quality assurance (QA) guidelines that can be applied to clinical treatment planning. This document is the report of Task Group 53 of the Radiation Therapy Committee of the American Association of Physicists in Medicine. The purpose of this report is to guide and assist the clinical medical physicist in developing and implementing a comprehensive but viable program of quality assurance for modern radiotherapy treatment planning. The scope of the QA needs for treatment planning is quite broad, encompassing image-based definition of patient anatomy, 3D beam descriptions for complex beams including multileaf collimator apertures, 3D dose calculation algorithms, and complex plan evaluation tools including dose volume histograms. The Task Group recommends an organizational framework for the task of creating a QA program which is individualized to the needs of each institution and addresses the issues of acceptance testing, commissioning the planning system and planning process, routine quality assurance, and ongoing QA of the planning process. This report, while not prescribing specific QA tests, provides the framework and guidance to allow radiation oncology physicists to design comprehensive and practical treatment planning QA programs for their clinics. PMID:9800687

  10. [Corticosteroids and radiotherapy in the treatment of Graves' ophthalmopathy].

    PubMed

    Nasr, Elie; Khater, Sherine; Nehme-Nasr, Dolly; Azoury, Fares; Jambart, Selim

    2010-01-01

    Graves' ophthalmopathy is a debilitating disease impairing the quality of life of affected individuals. The management of moderate-to-severe active Graves' ophthalmopathy is a major therapeutic challenge, and the treatment outcome is often unsatisfactory. We have carried out a retrospective study to assess the efficacy of combined orbital irradiation and systemic corticosteroids. Ten patients were included; all patients had received 20 Grays to the retrobulbar tissues in ten fractions, and oral or intravenous glucocorticoids. The main therapeutic outcome measures were the criteria of Donaldson and co-workers and a self-assessment evaluation. The quality of life outcome was also evaluated by the GO-QOL (Graves' ophthalmopathy quality of life) questionnaire. Seven patients (70%) demonstrated improvement in ocular parameters; the response was excellent in three cases, good in three cases and fair in one case. Three patients showed no response to the treatment. The self-assessment evaluation showed that 75% of patients were satisfied with the results of the treatment. Proptosis was the most responsive sign to radiation and steroids. A duration of the eye disease of more than 18 months was associated with less improvement and a higher failure of the treatment. Concerning the quality of life, the score for visual fonctionning was 882 +/- 18.2 after treatment, while the score for appearance was 63.3 +/- 23.3. In conclusion, a combination of orbital irradiation and systemic steroids is associated with 70% of favorable responses, but the quality of life is not restored in the same proportions and remains impaired after treatment. PMID:20549894

  11. Celastrol Potentiates Radiotherapy by Impairment of DNA Damage Processing in Human Prostate Cancer

    SciTech Connect

    Dai Yao; DeSano, Jeffrey T.; Meng Yang; J, Qing; Ljungman, Mats; Lawrence, Theodore S.; Xu Liang

    2009-07-15

    Purpose: Celastrol is an active ingredient of traditional herbal medicine and has recently been identified as a potent natural proteasome inhibitor. In the present study, we evaluated the radiosensitizing potential of celastrol in the human prostate cancer PC-3 model. Methods and Materials: Clonogenic assays were performed to determine the radiosensitizing effect of celastrol. Apoptosis was examined by flow cytometry using Annexin V and propidium iodide staining and by a caspase-3 activation assay. DNA damage processing was examined by immunofluorescent staining and Western blot for phosphorylated H2AX ({gamma}H2AX). The PC-3 xenograft model in the athymic nude mouse was used for the determination of the in vivo efficacy of celastrol combined with radiotherapy. The tumor samples were also analyzed for apoptosis and angiogenesis. Results: Celastrol sensitized PC-3 cells to ionizing radiation (IR) in a dose- and schedule-dependent manner, in which pretreatment with celastrol for 1 h followed by IR achieved maximal radiosensitization. Celastrol significantly prolonged the presence of IR-induced {gamma}H2AX and increased IR-induced apoptosis. Celastrol, combined with fractionated radiation, significantly inhibited PC-3 tumor growth in vivo without obvious systemic toxicity. The combination treatment increased {gamma}H2AX levels and apoptosis, induced cleavage of poly(adenosine diphosphate-ribose)polymerase and Mcl-1, and reduced angiogenesis in vivo compared with either treatment alone. Conclusion: Celastrol sensitized PC-3 cells to radiation both in vitro and in vivo by impairing DNA damage processing and augmenting apoptosis. Celastrol might represent a promising new adjuvant regimen for the treatment of hormone-refractory prostate cancer.

  12. Verifying radiotherapy treatment setup by interactive image registration.

    PubMed Central

    Boxwala, A. A.; Chaney, E. L.; Friedman, C. P.

    1996-01-01

    Digital image analysis techniques can be used to assist the physician in diagnostic or therapeutic decision making. In radiation oncology, portal image registration can improve the accuracy of detection of errors during radiation treatment. Following a discussion of the general paradigm of interactive image registration, we describe PortFolio, a workstation for portal image analysis. Images Figure 1 Figure 2 PMID:8947672

  13. Similar Treatment Outcomes for Radical Cystectomy and Radical Radiotherapy in Invasive Bladder Cancer Treated at a United Kingdom Specialist Treatment Center

    SciTech Connect

    Kotwal, Sanjeev; Choudhury, Ananya; Johnston, Colin; Paul, Alan B.; Whelan, Peter; Kiltie, Anne E.

    2008-02-01

    Purpose: To conduct a retrospective analysis within a large university teaching hospital, comparing outcomes between patients receiving either radical surgery or radiotherapy as curative treatment for bladder cancer. Patients and Methods: Between March 1996 and December 2000, 169 patients were treated radically for muscle-invasive bladder cancer. Data were collected from patient notes. Statistical analyses were performed using Kaplan-Meier methods and Cox proportional hazards regression analysis to compare radiotherapy and surgical outcome data. Results: There was no difference in overall, cause-specific, and distant recurrence-free survival at 5 years between the two groups, despite the radiotherapy group being older (median age, 75.3 years vs. 68.2 years). There were 31 local bladder recurrences in the radiotherapy group (24 solitary), but there was no significant difference in distant recurrence-free survival. In a more recent (2002-2006) cohort, the median age of radiotherapy patients but not the cystectomy patients was higher than in the 1996-2000 cohort (78.4 years vs. 75.3 years for radiotherapy and 67.9 years vs. 68.2 years for surgery). Conclusions: Although the patients undergoing radical cystectomy were significantly younger than the radiotherapy patients, treatment modality did not influence survival. Bladder cancer patients are an increasingly elderly group. Radical radiotherapy is a viable treatment option for these patients, with the advantage of organ preservation.

  14. Forward treatment planning for modulated electron radiotherapy (MERT) employing Monte Carlo methods

    SciTech Connect

    Henzen, D. Manser, P.; Frei, D.; Volken, W.; Born, E. J.; Lössl, K.; Aebersold, D. M.; Fix, M. K.; Neuenschwander, H.; Stampanoni, M. F. M.

    2014-03-15

    Purpose: This paper describes the development of a forward planning process for modulated electron radiotherapy (MERT). The approach is based on a previously developed electron beam model used to calculate dose distributions of electron beams shaped by a photon multi leaf collimator (pMLC). Methods: As the electron beam model has already been implemented into the Swiss Monte Carlo Plan environment, the Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA) can be included in the planning process for MERT. In a first step, CT data are imported into Eclipse and a pMLC shaped electron beam is set up. This initial electron beam is then divided into segments, with the electron energy in each segment chosen according to the distal depth of the planning target volume (PTV) in beam direction. In order to improve the homogeneity of the dose distribution in the PTV, a feathering process (Gaussian edge feathering) is launched, which results in a number of feathered segments. For each of these segments a dose calculation is performed employing the in-house developed electron beam model along with the macro Monte Carlo dose calculation algorithm. Finally, an automated weight optimization of all segments is carried out and the total dose distribution is read back into Eclipse for display and evaluation. One academic and two clinical situations are investigated for possible benefits of MERT treatment compared to standard treatments performed in our clinics and treatment with a bolus electron conformal (BolusECT) method. Results: The MERT treatment plan of the academic case was superior to the standard single segment electron treatment plan in terms of organs at risk (OAR) sparing. Further, a comparison between an unfeathered and a feathered MERT plan showed better PTV coverage and homogeneity for the feathered plan, with V{sub 95%} increased from 90% to 96% and V{sub 107%} decreased from 8% to nearly 0%. For a clinical breast boost irradiation, the MERT plan

  15. PET/CT for Radiotherapy Treatment Planning in Patients With Soft Tissue Sarcomas

    SciTech Connect

    Karam, Irene; Devic, Slobodan; Hickeson, Marc; Roberge, David; Turcotte, Robert E.; Freeman, Carolyn R.

    2009-11-01

    Purpose: To study the possibility of incorporating positron emission tomography/computed tomography (PET/CT) information into radiotherapy treatment planning in patients with high-grade soft tissue sarcomas (STS). Methods and Materials: We studied 17 patients treated with preoperative radiotherapy at our institution from 2005 to 2007. All patients had a high-grade STS and had had a staging PET/CT scan. For each patient, an MRI-based gross tumor volume (GTV), considered to be the contemporary standard for radiotherapy treatment planning, was outlined on a T1-gadolinium enhanced axial MRI (GTV{sub MRI}), and a second set of GTVs were outlined using different threshold values on PET images (GTV{sub PET}). PET-based target volumes were compared with the MRI-based GTV. Threshold values for target contouring were determined as a multiple (from 2 to 10 times) of the background soft tissue uptake values (B) sampled over healthy tissue. Results: PET-based GTVs contoured using a threshold value of 2 or 2.5 most closely resembled the GTV{sub MRI} volumes. Higher threshold values lead to PET volumes much smaller than the GTV{sub MRI}. The standard deviations between the average volumes of GTV{sub PET} and GTV{sub MRI} ratios for all thresholds were large, ranging from 36% for 2 xB up to 93% for 10 xB. Maximum uptake-to-background ratio correlated poorly with the maximum standardized uptake values. Conclusions: It is unlikely that PET/CT will make a significant contribution in GTV definition for radiotherapy treatment planning in patients with STS using threshold methods on PET images. Future studies will focus on molecular imaging and tumor physiology.

  16. A comparison between anisotropic analytical and multigrid superposition dose calculation algorithms in radiotherapy treatment planning.

    PubMed

    Wu, Vincent W C; Tse, Teddy K H; Ho, Cola L M; Yeung, Eric C Y

    2013-01-01

    Monte Carlo (MC) simulation is currently the most accurate dose calculation algorithm in radiotherapy planning but requires relatively long processing time. Faster model-based algorithms such as the anisotropic analytical algorithm (AAA) by the Eclipse treatment planning system and multigrid superposition (MGS) by the XiO treatment planning system are 2 commonly used algorithms. This study compared AAA and MGS against MC, as the gold standard, on brain, nasopharynx, lung, and prostate cancer patients. Computed tomography of 6 patients of each cancer type was used. The same hypothetical treatment plan using the same machine and treatment prescription was computed for each case by each planning system using their respective dose calculation algorithm. The doses at reference points including (1) soft tissues only, (2) bones only, (3) air cavities only, (4) soft tissue-bone boundary (Soft/Bone), (5) soft tissue-air boundary (Soft/Air), and (6) bone-air boundary (Bone/Air), were measured and compared using the mean absolute percentage error (MAPE), which was a function of the percentage dose deviations from MC. Besides, the computation time of each treatment plan was recorded and compared. The MAPEs of MGS were significantly lower than AAA in all types of cancers (p<0.001). With regards to body density combinations, the MAPE of AAA ranged from 1.8% (soft tissue) to 4.9% (Bone/Air), whereas that of MGS from 1.6% (air cavities) to 2.9% (Soft/Bone). The MAPEs of MGS (2.6%±2.1) were significantly lower than that of AAA (3.7%±2.5) in all tissue density combinations (p<0.001). The mean computation time of AAA for all treatment plans was significantly lower than that of the MGS (p<0.001). Both AAA and MGS algorithms demonstrated dose deviations of less than 4.0% in most clinical cases and their performance was better in homogeneous tissues than at tissue boundaries. In general, MGS demonstrated relatively smaller dose deviations than AAA but required longer computation time

  17. A comparison between anisotropic analytical and multigrid superposition dose calculation algorithms in radiotherapy treatment planning

    SciTech Connect

    Wu, Vincent W.C.; Tse, Teddy K.H.; Ho, Cola L.M.; Yeung, Eric C.Y.

    2013-07-01

    Monte Carlo (MC) simulation is currently the most accurate dose calculation algorithm in radiotherapy planning but requires relatively long processing time. Faster model-based algorithms such as the anisotropic analytical algorithm (AAA) by the Eclipse treatment planning system and multigrid superposition (MGS) by the XiO treatment planning system are 2 commonly used algorithms. This study compared AAA and MGS against MC, as the gold standard, on brain, nasopharynx, lung, and prostate cancer patients. Computed tomography of 6 patients of each cancer type was used. The same hypothetical treatment plan using the same machine and treatment prescription was computed for each case by each planning system using their respective dose calculation algorithm. The doses at reference points including (1) soft tissues only, (2) bones only, (3) air cavities only, (4) soft tissue-bone boundary (Soft/Bone), (5) soft tissue-air boundary (Soft/Air), and (6) bone-air boundary (Bone/Air), were measured and compared using the mean absolute percentage error (MAPE), which was a function of the percentage dose deviations from MC. Besides, the computation time of each treatment plan was recorded and compared. The MAPEs of MGS were significantly lower than AAA in all types of cancers (p<0.001). With regards to body density combinations, the MAPE of AAA ranged from 1.8% (soft tissue) to 4.9% (Bone/Air), whereas that of MGS from 1.6% (air cavities) to 2.9% (Soft/Bone). The MAPEs of MGS (2.6%±2.1) were significantly lower than that of AAA (3.7%±2.5) in all tissue density combinations (p<0.001). The mean computation time of AAA for all treatment plans was significantly lower than that of the MGS (p<0.001). Both AAA and MGS algorithms demonstrated dose deviations of less than 4.0% in most clinical cases and their performance was better in homogeneous tissues than at tissue boundaries. In general, MGS demonstrated relatively smaller dose deviations than AAA but required longer computation time.

  18. Intraoperative Radiotherapy for Breast Cancer: The Lasting Effects of a Fleeting Treatment

    PubMed Central

    Rosenberg, Anne L.

    2014-01-01

    In well-selected patients who choose to pursue breast conservation therapy (BCT) for early-stage breast cancer, partial breast irradiation (PBI) delivered externally or intraoperatively, may be a viable alternative to conventional whole breast irradiation. Two large, contemporary randomized trials have demonstrated breast intraoperative radiotherapy (IORT) to be noninferior to whole breast external beam radiotherapy (EBRT) when assessing for ipsilateral breast tumor recurrence in select patients. Additionally, IORT and other PBI techniques are likely to be more widely adopted in the future because they improve patient convenience by offering an accelerated course of treatment. Coupled with these novel techniques for breast radiotherapy (RT) are distinct toxicity profiles and unique cosmetic alterations that differ from conventional breast EBRT and have the potential to impact disease surveillance and patient satisfaction. This paper will review the level-one evidence for treatment efficacy as well as important secondary endpoints like RT toxicity, breast cosmesis, quality of life, patient satisfaction, and surveillance mammography following BCT with IORT. PMID:25180098

  19. Prevention and treatment of chemo- and radiotherapy-induced oral mucositis.

    PubMed

    Demarosi, F; Bez, C; Carrassi, A

    2002-05-01

    The administration of many chemo-radiotherapy regimens in patients with cancer may be complicated by toxicities that limit the clinicians' abilities to deliver the most effective doses of active agents. Oral mucositis is a major dose-limiting toxic effect and the most important cause of morbidity in patients undergoing chemo-radiotherapy for head and neck cancers, in patients undergoing bone marrow transplantation and those receiving certain chemotherapeutic agents for a variety of human malignancies. The intent of this paper is to review preventive strategies and treatment approaches for patients with established oral mucositis. Many agents of differing mechanisms of action have been used in the prevention and treatment of oral mucositis induced by anticancer therapies. Currently, no intervention is completely successful at preventing or treating oral mucositis. The several solutions, drugs and methods used and studied in the prophylaxis and therapy of chemotherapy or radiotherapy-induced oral mucositis reflects the need of new, more efficient tools in the management of this complication. Current studies and our increasing understanding of the etiology and pathogenesis of oral mucositis will lead to new approaches to the management and improved quality of life for these patients. PMID:12070468

  20. A method for integrating computed tomography into radiotherapy planning and treatment.

    PubMed

    Ash, D V; Andrews, B; Stubbs, B

    1983-01-01

    A technique is described for accurate localisation and radiotherapy treatment planning for a wide range of intrathoracic, abdominal and pelvic tumours. It allows the patient to proceed in one step from a single examination by computed tomography (CT) to treatment and avoids the need for separate treatment simulation. Compatible laser-beam positioning systems between the CT scanner and treatment-machine rooms ensure accurate reproduction of patient position, so that CT data are directly applicable to treatment. The use of appropriate skin markers, which appear on the CT scan, allows accurate measurements of the distance of the centre of the planned volume from a tattoo placed on the patient at the time of the scan, and ensures that the planned treatment fields are accurately directed. PMID:6822045

  1. Challenges of radiotherapy: report on the 4D treatment planning workshop 2013.

    PubMed

    Knopf, Antje; Nill, Simeon; Yohannes, Indra; Graeff, Christian; Dowdell, Stephen; Kurz, Christopher; Sonke, Jan-Jakob; Biegun, Aleksandra K; Lang, Stephanie; McClelland, Jamie; Champion, Benjamin; Fast, Martin; Wölfelschneider, Jens; Gianoli, Chiara; Rucinski, Antoni; Baroni, Guido; Richter, Christian; van de Water, Steven; Grassberger, Clemens; Weber, Damien; Poulsen, Per; Shimizu, Shinichi; Bert, Christoph

    2014-11-01

    This report, compiled by experts on the treatment of mobile targets with advanced radiotherapy, summarizes the main conclusions and innovations achieved during the 4D treatment planning workshop 2013. This annual workshop focuses on research aiming to advance 4D radiotherapy treatments, including all critical aspects of time resolved delivery, such as in-room imaging, motion detection, motion managing, beam application, and quality assurance techniques. The report aims to revise achievements in the field and to discuss remaining challenges and potential solutions. As main achievements advances in the development of a standardized 4D phantom and in the area of 4D-treatment plan optimization were identified. Furthermore, it was noticed that MR imaging gains importance and high interest for sequential 4DCT/MR data sets was expressed, which represents a general trend of the field towards data covering a longer time period of motion. A new point of attention was work related to dose reconstructions, which may play a major role in verification of 4D treatment deliveries. The experimental validation of results achieved by 4D treatment planning and the systematic evaluation of different deformable image registration methods especially for inter-modality fusions were identified as major remaining challenges. A challenge that was also suggested as focus for future 4D workshops was the adaptation of image guidance approaches from conventional radiotherapy into particle therapy. Besides summarizing the last workshop, the authors also want to point out new evolving demands and give an outlook on the focus of the next workshop. PMID:25172392

  2. Three-dimensional conformal radiotherapy in the treatment of prostate cancer in Australia and New Zealand: Report on a survey of radiotherapy centres and the proceedings of a consensus workshop.

    PubMed

    Tai, K-H; Duchesne, G; Turner, S; Kneebone, A; See, A; Gogna, K; Berry, M

    2004-12-01

    There is an increasing use of 3-D conformal radiotherapy (3DCRT) in the radiotherapeutic management of prostate cancer. The Faculty of Radiation Oncology Genito-Urinary Group carried out a survey of Australian and New Zealand radiotherapy centres in the preparation of a consensus workshop. Of the 19 centres that were represented, there were 24 radiation oncologists, 16 radiation therapists and 12 medical physicists. The survey collected demographic information and data on the practices undertaken at those centres when delivering curative radiotherapy in the treatment of prostate cancer. There was much variation in the delivery of treatment in the areas of patient set-up, contouring of target volumes and organs of interest during computer planning, the techniques and the dose constraints used in these techniques, the use of adjuvant androgen deprivation therapy and the quality assurance processes used in monitoring effects of treatment. This variability reflects the range of data in the published literature. Emerging trends of practices were also identified. This is a first report on a multi-disciplinary approach to the development of guidelines in 3DCRT of prostate cancer. PMID:15601331

  3. Dose calculation accuracies in whole breast radiotherapy treatment planning: a multi-institutional study.

    PubMed

    Hatanaka, Shogo; Miyabe, Yuki; Tohyama, Naoki; Kumazaki, Yu; Kurooka, Masahiko; Okamoto, Hiroyuki; Tachibana, Hidenobu; Kito, Satoshi; Wakita, Akihisa; Ohotomo, Yuko; Ikagawa, Hiroyuki; Ishikura, Satoshi; Nozaki, Miwako; Kagami, Yoshikazu; Hiraoka, Masahiro; Nishio, Teiji

    2015-07-01

    Our objective in this study was to evaluate the variation in the doses delivered among institutions due to dose calculation inaccuracies in whole breast radiotherapy. We have developed practical procedures for quality assurance (QA) of radiation treatment planning systems. These QA procedures are designed to be performed easily at any institution and to permit comparisons of results across institutions. The dose calculation accuracy was evaluated across seven institutions using various irradiation conditions. In some conditions, there was a >3 % difference between the calculated dose and the measured dose. The dose calculation accuracy differs among institutions because it is dependent on both the dose calculation algorithm and beam modeling. The QA procedures in this study are useful for verifying the accuracy of the dose calculation algorithm and of the beam model before clinical use for whole breast radiotherapy. PMID:25646770

  4. Postoperative Radiotherapy for the Treatment of Solitary Fibrous Tumor With Malignant Transformation of the Pelvic

    PubMed Central

    Gao, Chao; Zhang, Yong; Jing, Ming; Qu, Wei; Li, Jia; Zhao, Xiang-Rong; Yu, Yong-Hua

    2016-01-01

    Abstract Solitary fibrous tumor of the pelvic is an uncommon neoplasm with nonspecific symptoms. Reports of malignant transformation are especially rare. We report a case of solitary fibrous tumor in pelvic. A unique feature of our case compared with previously reported is that this patient relapsed with malignant transformation and had significant response to radiotherapy. The patient was initially treated with surgery, followed by postoperative dimensional conformal intensity modulated radiation therapy (dynamic MLC VRIAN 23EX Linac, inversely optimized by the Eclipse system) to provide a radical cure for residual tumor. In this case, there were no signs of recurrence after six and a half years of further follow-up, indicating that postoperation radiotherapy may be an effective treatment for SFT with malignant transformation in pelvic. PMID:26765426

  5. Low-Dose Involved-Field Radiotherapy as Alternative Treatment of Nodular Lymphocyte Predominance Hodgkin's Lymphoma

    SciTech Connect

    Haas, Rick L.M. Girinsky, Theo; Aleman, Berthe; Henry-Amar, Michel; Boer, Jan-Paul de; Jong, Daphne de

    2009-07-15

    Purpose: Nodular lymphocyte predominance Hodgkin's lymphoma is a very rare disease, characterized by an indolent clinical course, with sometimes very late relapses occurring in a minority of all patients. Considerable discussion is ongoing on the treatment of primary and relapsed disease. Patients and Methods: A group of 9 patients were irradiated to a dose of 4 Gy on involved areas only. Results: After a median follow-up of 37 months (range, 6-66), the overall response rate was 89%. Six patients had complete remission (67%), two had partial remission (22%), and one had stable disease (11%). Of 8 patients, 5 developed local relapse 9-57 months after radiotherapy. No toxicity was noted. Conclusion: In nodular lymphocyte predominance Hodgkin's lymphoma, low-dose radiotherapy provided excellent response rates and lasting remissions without significant toxicity.

  6. Radiotherapy in the Treatment of Patients With Unresectable Extrahepatic Cholangiocarcinoma

    SciTech Connect

    Ghafoori, A. Paiman; Nelson, John W.; Willett, Christopher G.; Chino, Junzo; Tyler, Douglas S.; Hurwitz, Herbert I.; Uronis, Hope E.; Morse, Michael A.; Clough, Robert W.; Czito, Brian G.

    2011-11-01

    Purpose: Extrahepatic cholangiocarcinoma is an uncommon but lethal malignancy. We analyzed the role of definitive chemoradiotherapy for patients with nonmetastatic, locally advanced extrahepatic cholangiocarcinoma treated at a single institution. Methods and Materials: This retrospective analysis included 37 patients who underwent external beam radiation therapy (EBRT) with concurrent chemotherapy and/or brachytherapy (BT) for locally advanced extrahepatic cholangiocarcinoma. Local control (LC) and overall survival (OS) were assessed, and univariate regression analysis was used to evaluate the effects of patient- and treatment-related factors on clinical outcomes. Results: Twenty-three patients received EBRT alone, 8 patients received EBRT plus BT, and 6 patients received BT alone (median follow-up of 14 months). Two patients were alive without evidence of recurrence at the time of analysis. Actuarial OS and LC rates at 1 year were 59% and 90%, respectively, and 22% and 71%, respectively, at 2 years. Two patients lived beyond 5 years without evidence of recurrence. On univariate analysis, EBRT with or without BT improved LC compared to BT alone (97% vs. 56% at 1 year; 75% vs. 56% at 2 years; p = 0.096). Patients who received EBRT alone vs. BT alone also had improved LC (96% vs. 56% at 1 year; 80% vs. 56% at 2 years; p = 0.113). Age, gender, tumor location (proximal vs. distal), histologic differentiation, EBRT dose ({<=} or >50 Gy), EBRT planning method (two-dimensional vs. three-dimensional), and chemotherapy were not associated with patient outcomes. Conclusions: Patients with locally advanced extrahepatic cholangiocarcinoma have poor survival. Long-term survival is rare. The majority of patients treated with EBRT had local control at the time of death, suggesting that symptoms due to the local tumor effect might be effectively controlled with radiation therapy, and EBRT is an important element of treatment. Novel treatment approaches are indicated in the therapy

  7. Prophylaxis versus treatment: Is there a better way to manage radiotherapy-induced nausea and vomiting?

    SciTech Connect

    Horiot, Jean-Claude . E-mail: horiotjc@dijon.fnclcc.fr

    2004-11-15

    Nausea and vomiting are two of the most distressing side effects of radiotherapy and cytotoxic drugs, which currently are often combined to treat moderately advanced and advanced solid tumors. Inadequate control of these symptoms may result in significant patient suffering and decrease in the patient's quality of life, which has been shown to decrease patients' compliance to treatment, with potential impact on disease outcome. It is, therefore, important that radiation oncologists recognize the need for adequate prophylactic treatment of radiation-induced nausea and vomiting (RINV) to avoid the detrimental effects on patients' quality of life, and optimize chances for cure. The 5-hydroxytryptamine type 3 (5-HT{sub 3})-receptor antagonists have been proved to provide effective antiemetic therapy in patients undergoing highly emetogenic radiotherapy. Nevertheless, several large surveys have shown that optimal treatments are not always used. Hence, a risk exists that waiting for RINV symptoms rather than prescribing prophylactic antiemetic treatment may lead to increased patient suffering, poorer disease control, and less cost-effective therapy options. Prophylactic management with an effective 5-HT{sub 3}-receptor antagonist should offer a better treatment option for patients at high to moderate risk of RINV. Adequate control of RINV should contribute to patient compliance to treatment, improved therapy outcomes, and decreased burdens on nursing and health care resources.

  8. Monte Carlo Treatment Planning for Molecular Targeted Radiotherapy within the MINERVA System

    SciTech Connect

    Lehmann, J; Siantar, C H; Wessol, D E; Wemple, C A; Nigg, D; Cogliati, J; Daly, T; Descalle, M; Flickinger, T; Pletcher, D; DeNardo, G

    2004-09-22

    The aim of this project is to extend accurate and patient-specific treatment planning to new treatment modalities, such as molecular targeted radiation therapy, incorporating previously crafted and proven Monte Carlo and deterministic computation methods. A flexible software environment is being created that allows planning radiation treatment for these new modalities and combining different forms of radiation treatment with consideration of biological effects. The system uses common input interfaces, medical image sets for definition of patient geometry, and dose reporting protocols. Previously, the Idaho National Engineering and Environmental Laboratory (INEEL), Montana State University (MSU), and Lawrence Livermore National Laboratory (LLNL) had accrued experience in the development and application of Monte Carlo-based, three-dimensional, computational dosimetry and treatment planning tools for radiotherapy in several specialized areas. In particular, INEEL and MSU have developed computational dosimetry systems for neutron radiotherapy and neutron capture therapy, while LLNL has developed the PEREGRINE computational system for external beam photon-electron therapy. Building on that experience, the INEEL and MSU are developing the MINERVA (Modality Inclusive Environment for Radiotherapeutic Variable Analysis) software system as a general framework for computational dosimetry and treatment planning for a variety of emerging forms of radiotherapy. In collaboration with this development, LLNL has extended its PEREGRINE code to accommodate internal sources for molecular targeted radiotherapy (MTR), and has interfaced it with the plug-in architecture of MINERVA. Results from the extended PEREGRINE code have been compared to published data from other codes, and found to be in general agreement (EGS4 - 2%, MCNP - 10%)(Descalle et al. 2003). The code is currently being benchmarked against experimental data. The interpatient variability of the drug pharmacokinetics in MTR

  9. Oral mucositis complicating chemotherapy and/or radiotherapy: options for prevention and treatment.

    PubMed

    Köstler, W J; Hejna, M; Wenzel, C; Zielinski, C C

    2001-01-01

    Chemotherapy- and radiotherapy-induced oral mucositis represents a therapeutic challenge frequently encountered in cancer patients. This side effect causes significant morbidity and may delay the treatment plan, as well as increase therapeutic expenses. The pathogenesis of this debilitating side effect can be attributed to the direct mucosal toxicity of cytotoxic agents and ionizing radiation and to indirect mucosal damage caused by a concomitant inflammatory reaction exacerbated in the presence of neutropenia, and the emergence of bacterial, mycotic, and viral infections. The prophylactic and therapeutic armamentarium for the treatment of oral mucositis consists of locally and systemically applied nonpharmacological measures and pharmacotherapeutics. PMID:11577493

  10. Monte Carlo treatment planning for molecular targeted radiotherapy within the MINERVA system.

    PubMed

    Lehmann, Joerg; Hartmann Siantar, Christine; Wessol, Daniel E; Wemple, Charles A; Nigg, David; Cogliati, Josh; Daly, Tom; Descalle, Marie-Anne; Flickinger, Terry; Pletcher, David; Denardo, Gerald

    2005-03-01

    The aim of this project is to extend accurate and patient-specific treatment planning to new treatment modalities, such as molecular targeted radiation therapy, incorporating previously crafted and proven Monte Carlo and deterministic computation methods. A flexible software environment is being created that allows planning radiation treatment for these new modalities and combining different forms of radiation treatment with consideration of biological effects. The system uses common input interfaces, medical image sets for definition of patient geometry and dose reporting protocols. Previously, the Idaho National Engineering and Environmental Laboratory (INEEL), Montana State University (MSU) and Lawrence Livermore National Laboratory (LLNL) had accrued experience in the development and application of Monte Carlo based, three-dimensional, computational dosimetry and treatment planning tools for radiotherapy in several specialized areas. In particular, INEEL and MSU have developed computational dosimetry systems for neutron radiotherapy and neutron capture therapy, while LLNL has developed the PEREGRINE computational system for external beam photon-electron therapy. Building on that experience, the INEEL and MSU are developing the MINERVA (modality inclusive environment for radiotherapeutic variable analysis) software system as a general framework for computational dosimetry and treatment planning for a variety of emerging forms of radiotherapy. In collaboration with this development, LLNL has extended its PEREGRINE code to accommodate internal sources for molecular targeted radiotherapy (MTR), and has interfaced it with the plugin architecture of MINERVA. Results from the extended PEREGRINE code have been compared to published data from other codes, and found to be in general agreement (EGS4-2%, MCNP-10%) (Descalle et al 2003 Cancer Biother. Radiopharm. 18 71-9). The code is currently being benchmarked against experimental data. The interpatient variability of the

  11. Involved-Node Radiotherapy and Modern Radiation Treatment Techniques in Patients With Hodgkin Lymphoma

    SciTech Connect

    Paumier, Amaury; Ghalibafian, Mithra; Beaudre, Anne; Ferreira, Ivaldo; Pichenot, Charlotte; Messai, Taha; Lessard, Nathalie Athalie; Lefkopoulos, Dimitri; Girinsky, Theodore

    2011-05-01

    Purpose: To assess the clinical outcome of the involved-node radiotherapy (INRT) concept using modern radiation treatments (intensity-modulated radiotherapy [IMRT]or deep-inspiration breath-hold radiotherapy [DIBH) in patients with localized supradiaphragmatic Hodgkin lymphoma. Methods and Materials: All but 2 patients had early-stage Hodgkin lymphoma, and they were treated with chemotherapy prior to irradiation. Radiation treatments were delivered using the INRT concept according to European Organization for Research and Treatment of Cancer guidelines. IMRT was performed with the patient free-breathing. For the adapted breath-hold technique, a spirometer dedicated to DIBH radiotherapy was used. Three-dimensional conformal radiotherapy was performed with those patients. Results: Fifty patients with Hodgkin lymphoma (48 patients with primary Hodgkin lymphoma, 1 patient with recurrent disease, and 1 patient with refractory disease) entered the study from January 2003 to August 2008. Thirty-two patients were treated with IMRT, and 18 patients were treated with the DIBH technique. The median age was 28 years (range, 17-62 years). Thirty-four (68%) patients had stage I - (I-IIA) IIA disease, and 16 (32%) patients had stage I - (I-IIB) IIB disease. All but 3 patients received three to six cycles of adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD). The median radiation doses to patients treated with IMRT and DIBH were, respectively, 40 Gy (range, 21.6-40 Gy) and 30.6 Gy (range, 19.8-40 Gy). Protection of various organs at risk was satisfactory. Median follow-up was 53.4 months (range, 19.1-93 months). The 5-year progression-free and overall survival rates for the whole population were 92% (95% confidence interval [CI], 80%-97%) and 94% (95% CI, 75%-98%), respectively. Recurrences occurred in 4 patients: 2 patients had in-field relapses, and 2 patients had visceral recurrences. Grade 3 acute lung toxicity (transient pneumonitis) occurred in 1 case. Conclusions

  12. Modified radiotherapy technique in the treatment of medulloblastoma

    SciTech Connect

    Dewit, L.; Van Dam, J.; Rijnders, A.; Van De Velde, G.; Ang, K.K.; Van Der Schueren, E.

    1984-02-01

    Craniospinal irradiation is a standard treatment technique in patients who receive surgery for medulloblastoma. In most centers megavoltage photon irradiation is used, resulting in significant irradiation exposure to critical organs. In order to overcome this difficulty, the authors recently modified the technique applied in their center, by using high energy electrons (20 MeV) for irradiation of the spinal cord. The reliability of this technique was checked by performing dosimetry in a specially constructed wax phantom. Attention was focused upon dose variations at the junction of fields. Furthermore, the influence of vertebrae on the absorbed dose distribution of high energy electrons is presented. This technique seems to be safe and reliable in selected patients (children and teenagers).

  13. A feasibility study of treatment verification using EPID cine images for hypofractionated lung radiotherapy

    NASA Astrophysics Data System (ADS)

    Tang, Xiaoli; Lin, Tong; Jiang, Steve

    2009-09-01

    We propose a novel approach for potential online treatment verification using cine EPID (electronic portal imaging device) images for hypofractionated lung radiotherapy based on a machine learning algorithm. Hypofractionated radiotherapy requires high precision. It is essential to effectively monitor the target to ensure that the tumor is within the beam aperture. We modeled the treatment verification problem as a two-class classification problem and applied an artificial neural network (ANN) to classify the cine EPID images acquired during the treatment into corresponding classes—with the tumor inside or outside of the beam aperture. Training samples were generated for the ANN using digitally reconstructed radiographs (DRRs) with artificially added shifts in the tumor location—to simulate cine EPID images with different tumor locations. Principal component analysis (PCA) was used to reduce the dimensionality of the training samples and cine EPID images acquired during the treatment. The proposed treatment verification algorithm was tested on five hypofractionated lung patients in a retrospective fashion. On average, our proposed algorithm achieved a 98.0% classification accuracy, a 97.6% recall rate and a 99.7% precision rate. This work was first presented at the Seventh International Conference on Machine Learning and Applications, San Diego, CA, USA, 11-13 December 2008.

  14. Treatment Planning Study to Determine Potential Benefit of Intensity-Modulated Radiotherapy Versus Conformal Radiotherapy for Unresectable Hepatic Malignancies

    SciTech Connect

    Eccles, Cynthia L.; Bissonnette, Jean-Pierre; Craig, Tim; Taremi, Mojgan; Wu Xia; Dawson, Laura A.

    2008-10-01

    Purpose: To compare intensity-modulated radiotherapy (IMRT) with conformal RT (CRT) for hypofractionated isotoxicity liver RT and explore dose escalation using IMRT for the same/improved nominal risk of liver toxicity in a treatment planning study. Methods and Materials: A total of 26 CRT plans were evaluated. Prescription doses (24-54 Gy within six fractions) were individualized on the basis of the effective liver volume irradiated maintaining {<=}5% risk of radiation-induced liver disease. The dose constraints included bowel (0.5 cm{sup 3}) and stomach (0.5 cm{sup 3}) to {<=}30 Gy, spinal cord to {<=}25 Gy, and planning target volume (PTV) to {<=}140% of the prescribed dose. Two groups were evaluated: (1) PTV overlapping or directly adjacent to serial functioning normal tissues (n = 14), and (2) the liver as the dose-limiting normal tissue (n = 12). IMRT plans using direct machine parameter optimization maintained the CRT plan beam arrangements, an estimated radiation-induced liver disease risk of 5%, and underwent dose escalation, if all normal tissue constraints were maintained. Results: IMRT improved PTV coverage in 19 of 26 plans (73%). Dose escalation was feasible in 9 cases by an average of 3.8 Gy (range, 0.6-13.2) in six fractions. Three of seven plans without improved PTV coverage had small gross tumor volumes ({<=}105 cm{sup 3}) already receiving 54 Gy, the maximal prescription dose allowed. In the remaining cases, the PTV range was 9.6-689 cm{sup 3}; two had overlapped organs at risk; and one had four targets. IMRT did not improve these plans owing to poor target coverage (n = 2) and nonliver (n = 2) dose limits. Conclusion: Direct machine parameter optimization IMRT improved PTV coverage while maintaining normal tissue tolerances in most CRT liver plans. Dose escalation was possible in a minority of patients.

  15. Combination ibandronate and radiotherapy for the treatment of bone metastases: Clinical evaluation and radiologic assessment

    SciTech Connect

    Vassiliou, Vassilios; Kalogeropoulou, Christine; Christopoulos, Christos; Solomou, Ekaterini; Leotsinides, Michael; Kardamakis, Dimitrios . E-mail: kardim@med.upatras.gr

    2007-01-01

    Purpose: Ibandronate is a single-nitrogen, noncyclic bisphosphonate with proven efficacy for reducing metastatic bone pain. In this study, we assessed the palliative effects of combined ibandronate and radiotherapy. Methods and Materials: Forty-five patients with bone metastases from various solid tumors received external-beam radiotherapy, 30-40 Gy over 3-4.5, weeks combined with 10 cycles of monthly intravenous ibandronate, 6 mg. Results: After combined therapy, mean bone pain scores (graded from 0 to 10) were reduced from 6.3 at baseline to 0.8 after 3 months, with further reductions at later time points (all p < 0.001). Opioid use decreased from 84% of patients at baseline (38/45) to 24% (11/45) at 3 months, with further subsequent reductions (all p < 0.001). Mean performance status and functioning scores also significantly improved. Bone density (assessed by computed tomography scan) increased by 20% vs. baseline at 3 months, 46% at 6 months, and 73% at 10 months (all p < 0.001). Lesion improvement was also demonstrated by magnetic resonance imaging. Treatment was well tolerated with no renal toxicity. Conclusions: In this pilot study, combined radiotherapy and ibandronate provided substantial bone pain relief and increased bone density. Computed tomography-based or magnetic resonance imaging-based evaluations offer objective methods for assessing therapeutic outcomes.

  16. Voice quality after treatment for T1a glottic carcinoma--radiotherapy versus laser cordectomy.

    PubMed

    Krengli, Marco; Policarpo, Mario; Manfredda, Irene; Aluffi, Paolo; Gambaro, Giuseppina; Panella, Massimiliano; Pia, Francesco

    2004-01-01

    The purpose of this study was to assess the anatomic and functional outcomes and compare the voice quality in patients affected by T1a glottic carcinoma treated with curative intent with radiotherapy or laser cordectomy. Fifty-seven cases were analysed: 27 after curative radiotherapy and 30 after laser cordectomy. All patients were studied with videolaryngostroboscopy, voice analysis by narrow spectrogram, and vocal parameters (Jitter, Shimmer, noise/harmonic ratio, and diplophonia). Videolaryngostroboscopy showed severe glottic inadequacy in 25% of cases treated with radiation and insufficient compensation 'ventricular band' or 'with arytenoid hyperadduction' in 65% of cases after surgery. Severe dysphonia on the electro-acoustic analysis of voice was observed in 25% of cases after radiation and 70% after laser (p < 0.001). Fundamental frequency and vocal parameters showed more favourable results in the radiation group (p < 0.001). Voice assessment showed better results after radiotherapy compared with laser cordectomy. Voice outcome should be carefully considered in the treatment decision for T1 glottic carcinoma. PMID:15244253

  17. Treatment of refractory low grade lymphoma with chlorambucil alternating with interferon and radiotherapy.

    PubMed

    Avilés, A; Talavera, A; Guzmán, R; Cuadra, I

    1995-01-01

    We report the results of a clinical trial of chlorambucil (CB) alternating with interferon alfa 2b (IFN) in previously treated patients with low-grade lymphoma who were refractory to previous treatment. Patients received CB 10 mg/m2, po, daily, days 1-14, alternating with IFN 5.0 MU three times a week days 15-28 (six doses) by six monthly cycles. If partial response was achieved, patients received extended field radiotherapy to sites of nodal residual postchemotherapy disease. Forty-three patients were enrolled into the study, and 30 were evaluable for response and toxicity. Nineteen out of 39 (40%) achieved complete remission and 14 out of 39 (35%) had partial remission, thus the overall response was observed in 83% of the cases. Ten patients with partial response and residual nodal disease received radiotherapy and achieved complete response criteria. The median duration of response has not been achieved, yet, 23 patients remain in complete response after a median follow-up of 98.5 months. Toxicity was mild and 95% of the patients received the planned dose of CB and IFN. These results suggest that combination of CB and IFN and addition of radiotherapy to residual postchemotherapy nodal disease may be effective in patients with low-grade lymphoma without excessive toxicity and adequate quality of life. PMID:8590892

  18. SU-C-17A-07: The Development of An MR Accelerator-Enabled Planning-To-Delivery Technique for Stereotactic Palliative Radiotherapy Treatment of Spinal Metastases

    SciTech Connect

    Hoogcarspel, S J; Kontaxis, C; Velden, J M van der; Bol, G H; Vulpen, M van; Lagendijk, J J W; Raaymakers, B W

    2014-06-01

    Purpose: To develop an MR accelerator-enabled online planning-todelivery technique for stereotactic palliative radiotherapy treatment of spinal metastases. The technical challenges include; automated stereotactic treatment planning, online MR-based dose calculation and MR guidance during treatment. Methods: Using the CT data of 20 patients previously treated at our institution, a class solution for automated treatment planning for spinal bone metastases was created. For accurate dose simulation right before treatment, we fused geometrically correct online MR data with pretreatment CT data of the target volume (TV). For target tracking during treatment, a dynamic T2-weighted TSE MR sequence was developed. An in house developed GPU based IMRT optimization and dose calculation algorithm was used for fast treatment planning and simulation. An automatically generated treatment plan developed with this treatment planning system was irradiated on a clinical 6 MV linear accelerator and evaluated using a Delta4 dosimeter. Results: The automated treatment planning method yielded clinically viable plans for all patients. The MR-CT fusion based dose calculation accuracy was within 2% as compared to calculations performed with original CT data. The dynamic T2-weighted TSE MR Sequence was able to provide an update of the anatomical location of the TV every 10 seconds. Dose calculation and optimization of the automatically generated treatment plans using only one GPU took on average 8 minutes. The Delta4 measurement of the irradiated plan agreed with the dose calculation with a 3%/3mm gamma pass rate of 86.4%. Conclusions: The development of an MR accelerator-enabled planning-todelivery technique for stereotactic palliative radiotherapy treatment of spinal metastases was presented. Future work will involve developing an intrafraction motion adaptation strategy, MR-only dose calculation, radiotherapy quality-assurance in a magnetic field, and streamlining the entire treatment

  19. An integrated Monte Carlo dosimetric verification system for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Yamamoto, T.; Mizowaki, T.; Miyabe, Y.; Takegawa, H.; Narita, Y.; Yano, S.; Nagata, Y.; Teshima, T.; Hiraoka, M.

    2007-04-01

    An integrated Monte Carlo (MC) dose calculation system, MCRTV (Monte Carlo for radiotherapy treatment plan verification), has been developed for clinical treatment plan verification, especially for routine quality assurance (QA) of intensity-modulated radiotherapy (IMRT) plans. The MCRTV system consists of the EGS4/PRESTA MC codes originally written for particle transport through the accelerator, the multileaf collimator (MLC), and the patient/phantom, which run on a 28-CPU Linux cluster, and the associated software developed for the clinical implementation. MCRTV has an interface with a commercial treatment planning system (TPS) (Eclipse, Varian Medical Systems, Palo Alto, CA, USA) and reads the information needed for MC computation transferred in DICOM-RT format. The key features of MCRTV have been presented in detail in this paper. The phase-space data of our 15 MV photon beam from a Varian Clinac 2300C/D have been developed and several benchmarks have been performed under homogeneous and several inhomogeneous conditions (including water, aluminium, lung and bone media). The MC results agreed with the ionization chamber measurements to within 1% and 2% for homogeneous and inhomogeneous conditions, respectively. The MC calculation for a clinical prostate IMRT treatment plan validated the implementation of the beams and the patient/phantom configuration in MCRTV.

  20. Complete remission of anaplastic thyroid carcinoma after concomitant treatment with docetaxel and radiotherapy.

    PubMed

    Abe, Ichiro; Karasaki, Satoko; Matsuda, Yayoi; Sakamoto, Shohei; Nakashima, Torahiko; Yamamoto, Hidetaka; Kawate, Hisaya; Ohnaka, Keizo; Nakashima, Hisashi; Kobayashi, Kunihisa; Oda, Yoshinao; Nomura, Masatoshi; Takayanagi, Ryoichi

    2015-01-01

    Anaplastic thyroid carcinoma (ATC) although rare is the most lethal form of thyroid cancer. The mortality rate for ATC is very high, with a median survival time of only 5 months; the survival rate at 1 year after diagnosis is <20%. Management of ATC is extremely difficult and rife with uncertainties. Herein, we describe a 75-year-old woman who presented with ATC and was successfully treated using concomitant treatment with docetaxel and high-dose radiotherapy. This case appears to be the first to have been reported in the literature involving complete remission of ATC confirmed by autopsy, suggesting the therapeutic potential of this combination. PMID:25789182

  1. Complete Remission of Anaplastic Thyroid Carcinoma after Concomitant Treatment with Docetaxel and Radiotherapy

    PubMed Central

    Abe, Ichiro; Karasaki, Satoko; Matsuda, Yayoi; Sakamoto, Shohei; Nakashima, Torahiko; Yamamoto, Hidetaka; Kawate, Hisaya; Ohnaka, Keizo; Nakashima, Hisashi; Kobayashi, Kunihisa; Oda, Yoshinao; Nomura, Masatoshi; Takayanagi, Ryoichi

    2015-01-01

    Anaplastic thyroid carcinoma (ATC) although rare is the most lethal form of thyroid cancer. The mortality rate for ATC is very high, with a median survival time of only 5 months; the survival rate at 1 year after diagnosis is <20%. Management of ATC is extremely difficult and rife with uncertainties. Herein, we describe a 75-year-old woman who presented with ATC and was successfully treated using concomitant treatment with docetaxel and high-dose radiotherapy. This case appears to be the first to have been reported in the literature involving complete remission of ATC confirmed by autopsy, suggesting the therapeutic potential of this combination. PMID:25789182

  2. Boosting runtime-performance of photon pencil beam algorithms for radiotherapy treatment planning.

    PubMed

    Siggel, M; Ziegenhein, P; Nill, S; Oelfke, U

    2012-10-01

    Pencil beam algorithms are still considered as standard photon dose calculation methods in Radiotherapy treatment planning for many clinical applications. Despite their established role in radiotherapy planning their performance and clinical applicability has to be continuously adapted to evolving complex treatment techniques such as adaptive radiation therapy (ART). We herewith report on a new highly efficient version of a well-established pencil beam convolution algorithm which relies purely on measured input data. A method was developed that improves raytracing efficiency by exploiting the capability of modern CPU architecture for a runtime reduction. Since most of the current desktop computers provide more than one calculation unit we used symmetric multiprocessing extensively to parallelize the workload and thus decreasing the algorithmic runtime. To maximize the advantage of code parallelization, we present two implementation strategies - one for the dose calculation in inverse planning software, and one for traditional forward planning. As a result, we could achieve on a 16-core personal computer with AMD processors a superlinear speedup factor of approx. 18 for calculating the dose distribution of typical forward IMRT treatment plans. PMID:22071169

  3. Comparison of selected dose calculation algorithms in radiotherapy treatment planning for tissues with inhomogeneities

    NASA Astrophysics Data System (ADS)

    Woon, Y. L.; Heng, S. P.; Wong, J. H. D.; Ung, N. M.

    2016-03-01

    Inhomogeneity correction is recommended for accurate dose calculation in radiotherapy treatment planning since human body are highly inhomogeneous with the presence of bones and air cavities. However, each dose calculation algorithm has its own limitations. This study is to assess the accuracy of five algorithms that are currently implemented for treatment planning, including pencil beam convolution (PBC), superposition (SP), anisotropic analytical algorithm (AAA), Monte Carlo (MC) and Acuros XB (AXB). The calculated dose was compared with the measured dose using radiochromic film (Gafchromic EBT2) in inhomogeneous phantoms. In addition, the dosimetric impact of different algorithms on intensity modulated radiotherapy (IMRT) was studied for head and neck region. MC had the best agreement with the measured percentage depth dose (PDD) within the inhomogeneous region. This was followed by AXB, AAA, SP and PBC. For IMRT planning, MC algorithm is recommended for treatment planning in preference to PBC and SP. The MC and AXB algorithms were found to have better accuracy in terms of inhomogeneity correction and should be used for tumour volume within the proximity of inhomogeneous structures.

  4. Adjuvant radiotherapy in the treatment of gall bladder carcinoma: What is the current evidence.

    PubMed

    Mallick, Supriya; Benson, Rony; Haresh, K P; Julka, P K; Rath, G K

    2016-03-01

    Gall bladder carcinoma (GBC) is considered the fifth most common one of the most aggressive gastro intestinal tract malignancies. Owing to their large incidence randomised controlled trials have hardly been conducted to look into their optimum treatment. Over the years surgical resection has been considered the only curative treatment of these tumors. However, the outcome still remains guarded. The predominant pattern of failure is loco-regional followed by systemic. Hence, local adjuvant radiation has been used by different institutes with concurrent and adjuvant chemotherapy. The large retrospective series with their limitations showed improved survival in patients with regional spread or tumors infiltrating the liver when treated with adjuvant radiotherapy. In the present era with modern radiation techniques and target delineation radiation may further improve upon the impact without adding to the toxicity profile. Hence, radiation in gall bladder cancer needs a relook to optimize treatment outcome of such aggressive disease. PMID:26265290

  5. Low-Dose-Rate Californium-252 Neutron Intracavitary Afterloading Radiotherapy Combined With Conformal Radiotherapy for Treatment of Cervical Cancer

    SciTech Connect

    Zhang Min; Xu Hongde; Pan Songdan; Lin Shan; Yue Jianhua; Liu Jianren

    2012-07-01

    Purpose: To study the efficacy of low-dose-rate californium-252 ({sup 252}Cf) neutron intracavitary afterloading radiotherapy (RT) combined with external pelvic RT for treatment of cervical cancer. Methods and Materials: The records of 96 patients treated for cervical cancer from 2006 to 2010 were retrospectively reviewed. For patients with tumors {<=}4 cm in diameter, external beam radiation was performed (1.8 Gy/day, five times/week) until the dose reached 20 Gy, and then {sup 252}Cf neutron intracavitary afterloading RT (once/week) was begun, and the frequency of external beam radiation was changed to four times/week. For patients with tumors >4 cm, {sup 252}Cf RT was performed one to two times before whole-pelvis external beam radiation. The tumor-eliminating dose was determined by using the depth limit of 5 mm below the mucosa as the reference point. In all patients, the total dose of the external beam radiation ranged from 46.8 to 50 Gy. For {sup 252}Cf RT, the dose delivered to point A was 6 Gy/fraction, once per week, for a total of seven times, and the total dose was 42 Gy. Results: The mean {+-} SD patient age was 54.7 {+-} 13.7 years. Six patients had disease assessed at stage IB, 13 patients had stage IIA, 49 patients had stage IIB, 3 patients had stage IIIA, 24 patients had stage IIIB, and 1 patient had stage IVA. All patients obtained complete tumor regression (CR). The mean {+-} SD time to CR was 23.5 {+-} 3.4 days. Vaginal bleeding was fully controlled in 80 patients within 1 to 8 days. The mean {+-} SD follow-up period was 27.6 {+-} 12.7 months (range, 6-48 months). Five patients died due to recurrence or metastasis. The 3-year survival and disease-free recurrence rates were 89.6% and 87.5 %, respectively. Nine patients experienced mild radiation proctitis, and 4 patients developed radiocystitis. Conclusions: Low-dose-rate {sup 252}Cf neutron RT combined with external pelvic RT is effective for treating cervical cancer, with a low incidence of

  6. RTtxGap: An android radiobiological tool for compensation of radiotherapy treatment interruption

    NASA Astrophysics Data System (ADS)

    Yusoff, A. L.; Mohamad, M.; Abdullah, R.; Bhavaraju, V. M. K.; Nik Idris, N. R.

    2016-03-01

    Treatment interruption is not uncommon in radiotherapy. Common reasons for treatment interruption include machine breakdown, holidays and patient severe radiation reactions. Here RTtxGap, an Android application to assist calculations of compensation for treatment gap, is reported. It uses linear quadratic (LQ) model to calculate the biological effective dose (BED) that is used to solve for treatment gap compensations. Solutions are calculated using BED equation, with consideration for tissue proliferation. The accuracy of results has been verified using LQL Equiv software to be accurate within 1%. Five treatment interruption examples were used to illustrate the capability of the software to calculate the treatment compensation schedules. Solving these examples also illustrates the general consensus regarding compensating for unscheduled treatment interruptions, which ultimately involves balancing the BEDs of tumour and organ at risk. In addition to compensation for treatment gap, RTtxGap can also be used to calculate equivalent total dose in 2-Gy fraction (EQD2), to modify treatment schedule and to calculate alternative dose prescriptions having the same isoeffect.

  7. Stereotactic Fractionated Radiotherapy in the Treatment of Juxtapapillary Choroidal Melanoma: The McGill University Experience

    SciTech Connect

    Al-Wassia, Rolina; Dal Pra, Alan; Shun, Kitty; Shaban, Ahmed; Corriveau, Christine; Edelstein, Chaim; Deschenes, Jean; Ruo, Russel; Patrocinio, Horacio; Cury, Fabio L.B.; DeBlois, Francois; Shenouda, George

    2011-11-15

    Purpose: To report our experience with linear accelerator-based stereotactic fractionated radiotherapy in the treatment of juxtapapillary choroidal melanoma. Methods and Materials: We performed a retrospective review of 50 consecutive patients diagnosed with juxtapapillary choroidal melanoma and treated with linear accelerator-based stereotactic fractionated radiotherapy between April 2003 and December 2009. Patients with small to medium sized lesions (Collaborative Ocular Melanoma Study classification) located within 2 mm of the optic disc were included. The prescribed radiation dose was 60 Gy in 10 fractions. The primary endpoints included local control, enucleation-free survival, and complication rates. Results: The median follow-up was 29 months (range, 1-77 months). There were 31 males and 29 females, with a median age of 69 years (range, 30-92 years). Eighty-four percent of the patients had medium sized lesions, and 16% of patients had small sized lesions. There were four cases of local progression (8%) and three enucleations (6%). Actuarial local control rates at 2 and 5 years were 93% and 86%, respectively. Actuarial enucleation-free survival rates at 2 and 5 years were 94% and 84%, respectively. Actuarial complication rates at 2 and 5 years were 33% and 88%, respectively, for radiation-induced retinopathy; 9.3% and 46.9%, respectively, for dry eye; 12% and 53%, respectively, for cataract; 30% and 90%, respectively, for visual loss [Snellen acuity (decimal equivalent), <0.1]; 11% and 54%, respectively, for optic neuropathy; and 18% and 38%, respectively, for neovascular glaucoma. Conclusions: Linear accelerator-based stereotactic fractionated radiotherapy using 60 Gy in 10 fractions is safe and has an acceptable toxicity profile. It has been shown to be an effective noninvasive treatment for juxtapapillary choroidal melanomas.

  8. Physician Expectations of Treatment Outcomes for Patients With Brain Metastases Referred for Whole Brain Radiotherapy

    SciTech Connect

    Barnes, Elizabeth A.; Chow, Edward; Tsao, May N.; Bradley, Nicole M.; Doyle, Meagan; Li, Kathy; Lam, Kelvin; Danjoux, Cyril

    2010-01-15

    Purpose: Patients with advanced cancer are referred to our Rapid Response Radiotherapy Program for quick access to palliative radiotherapy. The primary objective of this prospective study was to determine the physician expectations of the treatment outcomes for patients with brain metastases referred for whole brain radiotherapy (WBRT). The secondary objectives were to determine the factors influencing the expectations and to examine the accuracy of the physician-estimated patient survival. Methods and Materials: Patients were identified during a 17-month period. The referring physicians were sent a survey by facsimile to be completed and returned before the patient consultation. Information was sought on the patient's disease status, the physician's expectations of WBRT, the estimated patient survival and performance status, and physician demographic data. Results: A total of 137 surveys were sent out, and the overall response rate was 57.7%. The median patient age was 66 years (range, 35-87), 78.5% had multiple brain metastases, 42.3% had a controlled primary tumor, and 62.3% had extracranial disease. WBRT was thought to stabilize neurologic symptoms, improve quality of life, and allow for a Decadron (dexamethasone) taper by >=94.9% of the referring physicians; 87.0% thought WBRT would improve performance status; 77.9% thought it would improve neurologic symptoms; and 40.8% thought it would improve survival. The referring physicians estimated patient survival as a median of 6.0 months; however, the actual survival was a median of 2.5 months, for a median individual difference of 1.9 months (p < .0001). Conclusion: Physicians referring patients with brain metastases for consideration of WBRT are often overly optimistic when estimating the clinical benefit of the treatment and overestimate patient survival. These findings highlight the need for education and additional research in this field.

  9. Radiotherapy treatment of non-melanoma skin cancer: a survey of current UK practice and commentary

    PubMed Central

    Slevin, N J; Sykes, A J; Rembielak, A

    2014-01-01

    Objective: In the ongoing absence of available trial data, a national survey was carried out to provide details on radiotherapy treatment strategy for non-melanoma skin cancer (NMSC). Methods: A survey of clinical oncologists treating NMSC was performed. The respondents were asked for basic information on workload as well as a proposed treatment strategy for various clinical scenarios for patients of varying fitness. Results: A total of 43 completed and 20 partially completed surveys were received. There was a wide variation in the workload and additional disease sites that respondents had responsibility for. Kilovoltage radiotherapy was available to 81% of responders. The respondents' approach was affected by the fitness of patients, with longer fractionation regimes proposed for younger, fitter patients and shorter or non-standard fractionations more likely for the infirm elderly. Four daily fractionation regimes (18–20 Gy in 1 fraction, 35 Gy in 5 fractions, 45 Gy in 10 fractions and 55 Gy in 20 fractions) were most commonly suggested. There was a large degree of variation in non-standard fractions proposed with significant potential differences in radiobiological effect. Concern over the use of kilovoltage photons on skin over cartilage was apparent, as was a reluctance to use radiotherapy in areas of increased risk of poor wound healing. Conclusion: The survey results largely showed practice to be in line with available published evidence. The variation seen in some areas, such as non-standard fractionation, would benefit from the publication of local outcomes to achieve a more consistent approach. Advances in knowledge: This study provides information on national practices and identifies variations, particularly within widespread use of non-standard fractionation. PMID:25189280

  10. Glioblastoma Treatment: Bypassing the Toxicity of Platinum Compounds by Using Liposomal Formulation and Increasing Treatment Efficiency With Concomitant Radiotherapy

    SciTech Connect

    Charest, Gabriel; Sanche, Leon; Fortin, David; Mathieu, David; Paquette, Benoit

    2012-09-01

    Purpose: Treatments of glioblastoma with cisplatin or oxaliplatin only marginally improve the overall survival of patients and cause important side effects. To prevent adverse effects, improve delivery, and optimize the tumor response to treatment in combination with radiotherapy, a potential approach consists of incorporating the platinum agent in a liposome. Methods and Materials: In this study, cisplatin, oxaliplatin, carboplatin, Lipoplatin (the liposomal formulation of cisplatin), and Lipoxal (the liposomal formulation of oxaliplatin) were tested on F98 glioma orthotopically implanted in Fischer rats. The platinum compounds were administered by intracarotid infusion and were assessed for the ability to reduce toxicity, improve cancer cell uptake, and increase survival of animals when combined or not combined with radiotherapy. Results: The tumor uptake was 2.4-fold more important for Lipoxal than the liposome-free oxaliplatin. Lipoxal also improved the specificity of oxaliplatin as shown by a higher ratio of tumor to right hemisphere uptake. Surprisingly, Lipoplatin led to lower tumor uptake compared with cisplatin. However, Lipoplatin had the advantage of largely reducing the toxicity of cisplatin and allowed us to capitalize on the anticancer activity of this agent. Conclusion: Among the five platinum compounds tested, carboplatin showed the best increase in survival when combined with radiation for treatment of glioma implanted in Fischer rats.

  11. A One-Step Cone-Beam CT-Enabled Planning-to-Treatment Model for Palliative Radiotherapy-From Development to Implementation

    SciTech Connect

    Wong, Rebecca K.S.; Letourneau, Daniel; Varma, Anita; Bissonnette, Jean Pierre; Fitzpatrick, David; Grabarz, Daniel; Elder, Christine; Martin, Melanie; Bezjak, Andrea; Panzarella, Tony; Gospodarowicz, Mary; Jaffray, David A.

    2012-11-01

    Purpose: To develop a cone-beam computed tomography (CT)-enabled one-step simulation-to-treatment process for the treatment of bone metastases. Methods and Materials: A three-phase prospective study was conducted. Patients requiring palliative radiotherapy to the spine, mediastinum, or abdomen/pelvis suitable for treatment with simple beam geometry ({<=}2 beams) were accrued. Phase A established the accuracy of cone-beam CT images for the purpose of gross tumor target volume (GTV) definition. Phase B evaluated the feasibility of implementing the cone-beam CT-enabled planning process at the treatment unit. Phase C evaluated the online cone-beam CT-enabled process for the planning and treatment of patients requiring radiotherapy for bone metastases. Results: Eighty-four patients participated in this study. Phase A (n = 9) established the adequacy of cone-beam CT images for target definition. Phase B (n = 45) established the quality of treatment plans to be adequate for clinical implementation for bone metastases. When the process was applied clinically in bone metastases (Phase C), the degree of overlap between planning computed tomography (PCT) and cone-beam CT for GTV and between PCT and cone-beam CT for treatment field was 82% {+-} 11% and 97% {+-} 4%, respectively. The oncologist's decision to accept the plan under a time-pressured environment remained of high quality, with the cone-beam CT-generated treatment plan delivering at least 90% of the prescribed dose to 100% {+-} 0% of the cone-beam CT planning target volume (PTV). With the assumption that the PCT PTV is the gold-standard target, the cone-beam CT-generated treatment plan delivered at least 90% and at least 95% of dose to 98% {+-} 2% and 97% {+-} 5% of the PCT PTV, respectively. The mean time for the online planning and treatment process was 32.7 {+-} 4.0 minutes. Patient satisfaction was high, with a trend for superior satisfaction with the cone-beam CT-enabled process. Conclusions: The cone-beam CT

  12. Concurrent multimodality image segmentation by active contours for radiotherapy treatment planning

    SciTech Connect

    El Naqa, Issam; Yang Deshan; Apte, Aditya; Khullar, Divya; Mutic, Sasa; Zheng Jie; Bradley, Jeffrey D.; Grigsby, Perry; Deasy, Joseph O.

    2007-12-15

    Multimodality imaging information is regularly used now in radiotherapy treatment planning for cancer patients. The authors are investigating methods to take advantage of all the imaging information available for joint target registration and segmentation, including multimodality images or multiple image sets from the same modality. In particular, the authors have developed variational methods based on multivalued level set deformable models for simultaneous 2D or 3D segmentation of multimodality images consisting of combinations of coregistered PET, CT, or MR data sets. The combined information is integrated to define the overall biophysical structure volume. The authors demonstrate the methods on three patient data sets, including a nonsmall cell lung cancer case with PET/CT, a cervix cancer case with PET/CT, and a prostate patient case with CT and MRI. CT, PET, and MR phantom data were also used for quantitative validation of the proposed multimodality segmentation approach. The corresponding Dice similarity coefficient (DSC) was 0.90{+-}0.02 (p<0.0001) with an estimated target volume error of 1.28{+-}1.23% volume. Preliminary results indicate that concurrent multimodality segmentation methods can provide a feasible and accurate framework for combining imaging data from different modalities and are potentially useful tools for the delineation of biophysical structure volumes in radiotherapy treatment planning.

  13. Fractionated Stereotactic Radiotherapy in the Treatment of Vestibular Schwannoma (Acoustic Neuroma): Predicting the Risk of Hydrocephalus;Vestibular schwannoma; Hydrocephalus; Fractionated; Stereotactic radiotherapy

    SciTech Connect

    Powell, Ceri; Micallef, Caroline; Gonsalves, Adam; Wharram, Bev; Ashley, Sue; Brada, Michael

    2011-07-15

    Purpose: To determine the incidence and predictive factors for the development of hydrocephalus in patients with acoustic neuromas (AN) treated with fractionated stereotactic radiotherapy. Patients and Methods: Seventy-two patients with AN were treated with fractionated stereotactic radiotherapy between 1998 and 2007 (45-50 Gy in 25-30 fractions over 5 to 6 weeks). The pretreatment MRI scan was assessed for tumor characteristics and anatomic distortion independently of subsequent outcome and correlated with the risk of hydrocephalus. Results: At a median follow-up of 49 months (range, 1-120 months), 5-year event-free survival was 95%. Eight patients (11%) developed hydrocephalus within 19 months of radiotherapy, which was successfully treated. On univariate analysis, pretreatment factors predictive of hydrocephalus were maximum diameter (p = 0.005), proximity to midline (p = 0.009), displacement of the fourth ventricle (p = 0.02), partial effacement of the fourth ventricle (p < 0.001), contact with the medulla (p = 0.005), and more brainstem structures (p = 0.004). On multivariate analysis, after adjusting for fourth ventricular effacement, no other variables remained independently associated with hydrocephalus formation. Conclusions: Fractionated stereotactic radiotherapy results in excellent tumor control of AN, albeit with a risk of developing hydrocephalus. Patients at high risk, identified as those with larger tumors with partial effacement of the fourth ventricle before treatment, should be monitored more closely during follow-up. It would also be preferable to offer treatment to patients with progressive AN while the risk of hydrocephalus is low, before the development of marked distortion of fourth ventricle before tumor diameter significantly exceeds 2 cm.

  14. Monte Carlo treatment planning with modulated electron radiotherapy: framework development and application

    NASA Astrophysics Data System (ADS)

    Alexander, Andrew William

    Within the field of medical physics, Monte Carlo radiation transport simulations are considered to be the most accurate method for the determination of dose distributions in patients. The McGill Monte Carlo treatment planning system (MMCTP), provides a flexible software environment to integrate Monte Carlo simulations with current and new treatment modalities. A developing treatment modality called energy and intensity modulated electron radiotherapy (MERT) is a promising modality, which has the fundamental capabilities to enhance the dosimetry of superficial targets. An objective of this work is to advance the research and development of MERT with the end goal of clinical use. To this end, we present the MMCTP system with an integrated toolkit for MERT planning and delivery of MERT fields. Delivery is achieved using an automated "few leaf electron collimator" (FLEC) and a controller. Aside from the MERT planning toolkit, the MMCTP system required numerous add-ons to perform the complex task of large-scale autonomous Monte Carlo simulations. The first was a DICOM import filter, followed by the implementation of DOSXYZnrc as a dose calculation engine and by logic methods for submitting and updating the status of Monte Carlo simulations. Within this work we validated the MMCTP system with a head and neck Monte Carlo recalculation study performed by a medical dosimetrist. The impact of MMCTP lies in the fact that it allows for systematic and platform independent large-scale Monte Carlo dose calculations for different treatment sites and treatment modalities. In addition to the MERT planning tools, various optimization algorithms were created external to MMCTP. The algorithms produced MERT treatment plans based on dose volume constraints that employ Monte Carlo pre-generated patient-specific kernels. The Monte Carlo kernels are generated from patient-specific Monte Carlo dose distributions within MMCTP. The structure of the MERT planning toolkit software and

  15. A review of dental treatment of head and neck cancer patients, before, during and after radiotherapy: part 2.

    PubMed

    Jawad, H; Hodson, N A; Nixon, P J

    2015-01-01

    The incidence of head and neck cancer is on the rise. Radiation therapy is one of the major treatment modalities for the management of oral malignancies. As with any treatment modality, radiation therapy is associated with various complications. The second part of this series is a review of the oral changes that occur during and after radiotherapy and the oral management of head and neck oncology patients before, during and after radiotherapy. Dental practitioners will encounter patients who have been affected by cancer or who are current cancer patents. General dental practitioners (GDPs) have a vital and proactive role in supporting such patients. The aim of this article is to review the oral management of these patients during and after radiotherapy, and gives practical advice for GDPs and their teams in the long-term care of these patients. PMID:25613261

  16. Patient-specific dosimetric endpoints based treatment plan quality control in radiotherapy

    NASA Astrophysics Data System (ADS)

    Song, Ting; Staub, David; Chen, Mingli; Lu, Weiguo; Tian, Zhen; Jia, Xun; Li, Yongbao; Zhou, Linghong; Jiang, Steve B.; Gu, Xuejun

    2015-11-01

    In intensity modulated radiotherapy (IMRT), the optimal plan for each patient is specific due to unique patient anatomy. To achieve such a plan, patient-specific dosimetric goals reflecting each patient’s unique anatomy should be defined and adopted in the treatment planning procedure for plan quality control. This study is to develop such a personalized treatment plan quality control tool by predicting patient-specific dosimetric endpoints (DEs). The incorporation of patient specific DEs is realized by a multi-OAR geometry-dosimetry model, capable of predicting optimal DEs based on the individual patient’s geometry. The overall quality of a treatment plan is then judged with a numerical treatment plan quality indicator and characterized as optimal or suboptimal. Taking advantage of clinically available prostate volumetric modulated arc therapy (VMAT) treatment plans, we built and evaluated our proposed plan quality control tool. Using our developed tool, six of twenty evaluated plans were identified as sub-optimal plans. After plan re-optimization, these suboptimal plans achieved better OAR dose sparing without sacrificing the PTV coverage, and the dosimetric endpoints of the re-optimized plans agreed well with the model predicted values, which validate the predictability of the proposed tool. In conclusion, the developed tool is able to accurately predict optimally achievable DEs of multiple OARs, identify suboptimal plans, and guide plan optimization. It is a useful tool for achieving patient-specific treatment plan quality control.

  17. Multiobjective optimization with a modified simulated annealing algorithm for external beam radiotherapy treatment planning

    SciTech Connect

    Aubry, Jean-Francois; Beaulieu, Frederic; Sevigny, Caroline; Beaulieu, Luc; Tremblay, Daniel

    2006-12-15

    Inverse planning in external beam radiotherapy often requires a scalar objective function that incorporates importance factors to mimic the planner's preferences between conflicting objectives. Defining those importance factors is not straightforward, and frequently leads to an iterative process in which the importance factors become variables of the optimization problem. In order to avoid this drawback of inverse planning, optimization using algorithms more suited to multiobjective optimization, such as evolutionary algorithms, has been suggested. However, much inverse planning software, including one based on simulated annealing developed at our institution, does not include multiobjective-oriented algorithms. This work investigates the performance of a modified simulated annealing algorithm used to drive aperture-based intensity-modulated radiotherapy inverse planning software in a multiobjective optimization framework. For a few test cases involving gastric cancer patients, the use of this new algorithm leads to an increase in optimization speed of a little more than a factor of 2 over a conventional simulated annealing algorithm, while giving a close approximation of the solutions produced by a standard simulated annealing. A simple graphical user interface designed to facilitate the decision-making process that follows an optimization is also presented.

  18. Radiotherapy for testicular seminoma stage I: treatment results and long-term post-irradiation morbidity in 365 patients

    SciTech Connect

    Fossa, S.D.A.; Aass, N.; Kaalhus, O.

    1989-02-01

    After infradiaphragmatic radiotherapy the cancer-related 10 year survival was 99% in 365 patients with seminoma Stage I referred to the Norwegian Radium Hospital between 1970 and 1982. Thirteen patients relapsed, 11 of them within the first 3 years after treatment. Nine of the recurrent patients were cured by radiotherapy alone (4) or in combination with chemotherapy (5). There is no need to include the inguinal lymph nodes into the irradiation field or to give scrotal irradiation, not even to patients with tumor infiltration beyond the testicular tissue, or to those with prior scrotal or inguinal surgery. At least 1 year after radiotherapy moderate or more severe dyspepsia was observed in 16 patients. Nine patients developed a peptic ulcer. In general, there was no increased risk for development of a second non-germ cell cancer after radiotherapy. However, 4 patients developed a pulmonary cancer indicating a border-line significance of increased risk for this type of malignancy. (p:0.05). In conclusion, infradiaphragmatic radiotherapy remains the optimal routine treatment in seminoma patients with Stage I.

  19. NOTE: MMCTP: a radiotherapy research environment for Monte Carlo and patient-specific treatment planning

    NASA Astrophysics Data System (ADS)

    Alexander, A.; DeBlois, F.; Stroian, G.; Al-Yahya, K.; Heath, E.; Seuntjens, J.

    2007-07-01

    Radiotherapy research lacks a flexible computational research environment for Monte Carlo (MC) and patient-specific treatment planning. The purpose of this study was to develop a flexible software package on low-cost hardware with the aim of integrating new patient-specific treatment planning with MC dose calculations suitable for large-scale prospective and retrospective treatment planning studies. We designed the software package 'McGill Monte Carlo treatment planning' (MMCTP) for the research development of MC and patient-specific treatment planning. The MMCTP design consists of a graphical user interface (GUI), which runs on a simple workstation connected through standard secure-shell protocol to a cluster for lengthy MC calculations. Treatment planning information (e.g., images, structures, beam geometry properties and dose distributions) is converted into a convenient MMCTP local file storage format designated, the McGill RT format. MMCTP features include (a) DICOM_RT, RTOG and CADPlan CART format imports; (b) 2D and 3D visualization views for images, structure contours, and dose distributions; (c) contouring tools; (d) DVH analysis, and dose matrix comparison tools; (e) external beam editing; (f) MC transport calculation from beam source to patient geometry for photon and electron beams. The MC input files, which are prepared from the beam geometry properties and patient information (e.g., images and structure contours), are uploaded and run on a cluster using shell commands controlled from the MMCTP GUI. The visualization, dose matrix operation and DVH tools offer extensive options for plan analysis and comparison between MC plans and plans imported from commercial treatment planning systems. The MMCTP GUI provides a flexible research platform for the development of patient-specific MC treatment planning for photon and electron external beam radiation therapy. The impact of this tool lies in the fact that it allows for systematic, platform

  20. SU-C-17A-01: MRI-Based Radiotherapy Treatment Planning In Pelvis

    SciTech Connect

    Hsu, S; Cao, Y; Jolly, S; Balter, J

    2014-06-15

    Purpose: To support radiotherapy dose calculation, synthetic CT (MRCT) image volumes need to represent the electron density of tissues with sufficient accuracy. This study compares CT and MRCT for pelvic radiotherapy. Methods: CT and multi-contrast MRI acquired using T1- based Dixon, T2 TSE, and PETRA sequences were acquired on an IRBapproved protocol patient. A previously published method was used to create a MRCT image volume by applying fuzzy classification on T1- weighted and calculated water image volumes (air and fluid voxels were excluded using thresholds applied to PETRA and T2-weighted images). The correlation of pelvic bone intensity between CT and MRCT was investigated. Two treatment plans, based on CT and MRCT, were performed to mimic treatment for: (a) pelvic bone metastasis with a 16MV parallel beam arrangement, and (b) gynecological cancer with 6MV volumetric modulated arc therapy (VMAT) using two full arcs. The CT-calculated fluence maps were used to recalculate doses using the MRCT-derived density grid. The dose-volume histograms and dose distributions were compared. Results: Bone intensities in the MRCT volume correlated linearly with CT intensities up to 800 HU (containing 96% of the bone volume), and then decreased with CT intensity increase (4% volume). There was no significant difference in dose distributions between CT- and MRCTbased plans, except for the rectum and bladder, for which the V45 differed by 15% and 9%, respectively. These differences may be attributed to normal and visualized organ movement and volume variations between CT and MR scans. Conclusion: While MRCT had lower bone intensity in highly-dense bone, this did not cause significant dose deviations from CT due to its small percentage of volume. These results indicate that treatment planning using MRCT could generate comparable dose distributions to that using CT, and further demonstrate the feasibility of using MRI-alone to support Radiation Oncology workflow. NIH R01EB016079.

  1. A trichrome beam model for biological dose calculation in scanned carbon-ion radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Inaniwa, T.; Kanematsu, N.

    2015-01-01

    In scanned carbon-ion (C-ion) radiotherapy, some primary C-ions undergo nuclear reactions before reaching the target and the resulting particles deliver doses to regions at a significant distance from the central axis of the beam. The effects of these particles on physical dose distribution are accounted for in treatment planning by representing the transverse profile of the scanned C-ion beam as the superposition of three Gaussian distributions. In the calculation of biological dose distribution, however, the radiation quality of the scanned C-ion beam has been assumed to be uniform over its cross-section, taking the average value over the plane at a given depth (monochrome model). Since these particles, which have relatively low radiation quality, spread widely compared to the primary C-ions, the radiation quality of the beam should vary with radial distance from the central beam axis. To represent its transverse distribution, we propose a trichrome beam model in which primary C-ions, heavy fragments with atomic number Z ≥ 3, and light fragments with Z ≤ 2 are assigned to the first, second, and third Gaussian components, respectively. Assuming a realistic beam-delivery system, we performed computer simulations using Geant4 Monte Carlo code for analytical beam modeling of the monochrome and trichrome models. The analytical beam models were integrated into a treatment planning system for scanned C-ion radiotherapy. A target volume of 20  ×  20  ×  40 mm3 was defined within a water phantom. A uniform biological dose of 2.65 Gy (RBE) was planned for the target with the two beam models based on the microdosimetric kinetic model (MKM). The plans were recalculated with Geant4, and the recalculated biological dose distributions were compared with the planned distributions. The mean target dose of the recalculated distribution with the monochrome model was 2.72 Gy (RBE), while the dose with the trichrome model was 2.64 Gy (RBE). The monochrome model

  2. Impact of Radiation in Critical Organs in Radiotherapy Treatment of Breast and Lung Cancers

    NASA Astrophysics Data System (ADS)

    Pyakuryal, Anil; Chen, Chiu-Hao; Dhungana, Sudarshan

    2010-02-01

    Various 3D conformal radiotherapy (3DCRT) techniques are commonly used in the treatment of cancerous tumors at appropriate prescription doses (PDs). The purpose of this study was to analyze the impact of radiation in heart and lungs in left breast and left lung cancer patients treated using 3DCRT techniques. Treatment plans for the eight breast cancer patients (n=8), eight lung cancer patients at early stage (m=8), and eight lung cancer patients at stage II and III (k=8) were evaluated. Relative complication probabilities (RCPs) for the irradiated organs were computed from the plans using HART [Med. Phys. 36, p.2547 (2009)] program at PD. The RCPs were found to be (i) 2.3% (n=8, PD=56 Gy), 6.4% (m=8, PD=30.7 Gy), and 16.7% (k=8, PD=54.8 Gy) for the heart, (ii) 1% (n=6, PD=58.4 Gy) for the left lung, and (iii) 7% (m=6, PD=31 Gy) and 5.3% (k=8, PD=54.8 Gy) for the whole lung. Homogeneous target coverage and improved dose conformality were the major advantages in the treatment of breast cancer. Therefore, simple 3DCRT based whole-breast irradiation and partial lung treatment techniques can offer promising results while adequately sparing the organs in the treatment of breast and lung cancers. )

  3. The effects of postoperative adjuvant chemotherapy and radiotherapy on testicular function in men undergoing treatment for soft tissue sarcoma

    SciTech Connect

    Shamberger, R.C.; Sherins, R.J.; Rosenberg, S.A.

    1981-05-15

    Testicular function was studied in 26 men with sarcoma who received adjuvant treatment with doxorubicin, cyclophosphamide, and high-dose methotrexate (with or without radiotherapy). Testicular size, sperm output, and serum FSH, LH and testosterone levels were assessed after treatment. Five of 17 men who received chemotherapy or chemotherapy with radiotherapy to the neck, arm, chest, or leg, had normal testicular function. Eight of the remaining 12 men who provided ejaculates were oligospermic or azoospermic and serum FSH was increased threefold and LH twofold; testosterone levels were normal. In the five men with normal testicular function, FSH was increased fourfold during therapy but returned to normal six to 21 months after treatment. In men less than 40 years old, the mean FSH was less than that of men over 40 years of age (P . to 0.05), suggesting that recovery from the injury was age-related. By contrast, all nine men who received chemotherapy plus radiotherapy to the abdomen or thigh had decreased testicular size, azoospermia, fourfold increase in FSH, and twofold increase in LH levels; but testosterone concentration was normal. These data increase in FSH, and reversible testicular injury occurs after treatment with doxorubicin, cyclophosphamide, and high-dose methotrexate; recovery is age-related. However, these agents in combination with use of adjuvant radiotherapy to the thigh or abdomen may produce permanent testicular injury even in young patients.

  4. MRI-based treatment plan simulation and adaptation for ion radiotherapy using a classification-based approach

    PubMed Central

    2013-01-01

    Background In order to benefit from the highly conformal irradiation of tumors in ion radiotherapy, sophisticated treatment planning and simulation are required. The purpose of this study was to investigate the potential of MRI for ion radiotherapy treatment plan simulation and adaptation using a classification-based approach. Methods Firstly, a voxelwise tissue classification was applied to derive pseudo CT numbers from MR images using up to 8 contrasts. Appropriate MR sequences and parameters were evaluated in cross-validation studies of three phantoms. Secondly, ion radiotherapy treatment plans were optimized using both MRI-based pseudo CT and reference CT and recalculated on reference CT. Finally, a target shift was simulated and a treatment plan adapted to the shift was optimized on a pseudo CT and compared to reference CT optimizations without plan adaptation. Results The derivation of pseudo CT values led to mean absolute errors in the range of 81 - 95 HU. Most significant deviations appeared at borders between air and different tissue classes and originated from partial volume effects. Simulations of ion radiotherapy treatment plans using pseudo CT for optimization revealed only small underdosages in distal regions of a target volume with deviations of the mean dose of PTV between 1.4 - 3.1% compared to reference CT optimizations. A plan adapted to the target volume shift and optimized on the pseudo CT exhibited a comparable target dose coverage as a non-adapted plan optimized on a reference CT. Conclusions We were able to show that a MRI-based derivation of pseudo CT values using a purely statistical classification approach is feasible although no physical relationship exists. Large errors appeared at compact bone classes and came from an imperfect distinction of bones and other tissue types in MRI. In simulations of treatment plans, it was demonstrated that these deviations are comparable to uncertainties of a target volume shift of 2 mm in two directions

  5. Neutron dosimetry in linear electron accelerator during radiotherapy treatment: simulation and experiment

    NASA Astrophysics Data System (ADS)

    Manfredotti, Claudio; Nastasi, U.; Ongaro, C.; Stasi, E.; Zanini, Alessandro

    1995-03-01

    In the electron linear accelerators used for radiotherapy by high energy electrons or gamma rays, there is a non negligible production of neutrons by photodisintegration or electrodisintegration reactions on the high Z components of the head machine (target, flattening filter, collimators). At the Experimental Physics Department of Torino University, Torino, Italy an experimental and theoretical evaluation has been performed on the undesired neutron production in the MD Class Mevatron Siemens accelerator used at the Radiotherapy Department of S. Giovanni Battista A.S. Hospital for cancer therapy by a 15 MV gamma ray beam. A simulation of the total process has been carried out, using EGS4 MonteCarlo computer code for the evaluation of photoneutron spectra and MCNP code for the neutron transport in the patient's body. The geometrical description both of the accelerator head in EGS4 and of the anthropomorphous phantom in MCNP have been highly optimized. Experimental measurements have been carried out by bubble detectors BD 100R appropriately allocated inside a new phantom in polyetylene and plexiglass, especially designed for this purpose.

  6. Benefit of Carbon Ion Radiotherapy in the Treatment of Radio-resistant Tumors

    NASA Astrophysics Data System (ADS)

    Kamada, Tadashi; Tsujii, Hirohiko; Tsuji, Hiroshi; Yanagi, Tsuyoshi; Imai, Reiko; Mizoe, Jun-etsu; Miyamoto, Tadaaki; Kato, Hirotoshi; Yamada, Shigeru; Kato, Shingo; Yoshikawa, Kyousan; Kandatsu, Susumu

    2003-08-01

    The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world's first heavy ion accelerator complex dedicated to medical use in a hospital environment. Heavy ions have superior depth-dose distribution and greater cell-killing ability. In June 1994, clinical research for the treatment of cancer was begun using carbon ions generated by HIMAC. Until August 2002, a total of 1,297 patients were enrolled in clinical trials. Most of the patients had locally advanced and/or medically inoperable tumors. Tumors radio-resistant and/or located near critical organs were also included. The clinical trials revealed that carbon ion radiotherapy provided definite local control and offered a survival advantage without unacceptable morbidity in a variety of tumors that were hard to cure by other modalities.

  7. Overview of recent advances in treatment planning for ion beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Krämer, Michael; Scifoni, Emanuele; Schmitz, Frederike; Sokol, Olga; Durante, Marco

    2014-10-01

    To achieve practical calculations of dose delivery in ion beam radiotherapy, the physical models of beam propagation need to be properly implemented and supplemented by models describing the complex mechanisms of radiation damage in the biological tissues. TRiP98 is the first and most advanced treatment planning system for particles, in which physical and biological models have been incorporated to develop a clinically applicable tool for dose optimization and delivery. We report our recent advances in TRiP98 code development, in particular towards hypoxia-driven and multi-modal dose optimization. We also discuss the present needs and possible extensions of our models for which input from nanoscale physics is required. Contribution to the Topical Issue "Nano-scale Insights into Ion-beam Cancer Therapy", edited by Andrey V. Solov'yov, Nigel Mason, Paulo Limão-Vieira and Malgorzata Smialek-Telega.

  8. Benefit of Carbon Ion Radiotherapy in the Treatment of Radio-resistant Tumors

    SciTech Connect

    Kamada, Tadashi; Tsujii, Hirohiko; Tsuji, Hiroshi; Yanagi, Tsuyoshi; Imai, Reiko; Mizoe, Jun-etsu; Miyamoto, Tadaaki; Kato, Hirotoshi; Yamada, Shigeru; Kato, Shingo; Yoshikawa, Kyousan; Kandatsu, Susumu

    2003-08-26

    The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world's first heavy ion accelerator complex dedicated to medical use in a hospital environment. Heavy ions have superior depth-dose distribution and greater cell-killing ability. In June 1994, clinical research for the treatment of cancer was begun using carbon ions generated by HIMAC. Until August 2002, a total of 1,297 patients were enrolled in clinical trials. Most of the patients had locally advanced and/or medically inoperable tumors. Tumors radio-resistant and/or located near critical organs were also included. The clinical trials revealed that carbon ion radiotherapy provided definite local control and offered a survival advantage without unacceptable morbidity in a variety of tumors that were hard to cure by other modalities.

  9. Correcting radiation survey data to account for increased leakage during intensity modulated radiotherapy treatments

    SciTech Connect

    Kairn, T.; Crowe, S. B.; Trapp, J. V.

    2013-11-15

    Purpose: Intensity modulated radiotherapy (IMRT) treatments require more beam-on time and produce more linac head leakage to deliver similar doses to conventional, unmodulated, radiotherapy treatments. It is necessary to take this increased leakage into account when evaluating the results of radiation surveys around bunkers that are, or will be, used for IMRT. The recommended procedure of applying a monitor-unit based workload correction factor to secondary barrier survey measurements, to account for this increased leakage when evaluating radiation survey measurements around IMRT bunkers, can lead to potentially costly overestimation of the required barrier thickness. This study aims to provide initial guidance on the validity of reducing the value of the correction factor when applied to different radiation barriers (primary barriers, doors, maze walls, and other walls) by evaluating three different bunker designs.Methods: Radiation survey measurements of primary, scattered, and leakage radiation were obtained at each of five survey points around each of three different radiotherapy bunkers and the contribution of leakage to the total measured radiation dose at each point was evaluated. Measurements at each survey point were made with the linac gantry set to 12 equidistant positions from 0° to 330°, to assess the effects of radiation beam direction on the results.Results: For all three bunker designs, less than 0.5% of dose measured at and alongside the primary barriers, less than 25% of the dose measured outside the bunker doors and up to 100% of the dose measured outside other secondary barriers was found to be caused by linac head leakage.Conclusions: Results of this study suggest that IMRT workload corrections are unnecessary, for survey measurements made at and alongside primary barriers. Use of reduced IMRT workload correction factors is recommended when evaluating survey measurements around a bunker door, provided that a subset of the measurements used in

  10. Tally and geometry definition influence on the computing time in radiotherapy treatment planning with MCNP Monte Carlo code.

    PubMed

    Juste, B; Miro, R; Gallardo, S; Santos, A; Verdu, G

    2006-01-01

    The present work has simulated the photon and electron transport in a Theratron 780 (MDS Nordion) (60)Co radiotherapy unit, using the Monte Carlo transport code, MCNP (Monte Carlo N-Particle), version 5. In order to become computationally more efficient in view of taking part in the practical field of radiotherapy treatment planning, this work is focused mainly on the analysis of dose results and on the required computing time of different tallies applied in the model to speed up calculations. PMID:17946330

  11. Fractionated Stereotactic Radiotherapy Treatment of Cavernous Sinus Meningiomas: A Study of 100 Cases

    SciTech Connect

    Litre, Claude Fabien Colin, Philippe; Noudel, Remy; Peruzzi, Philippe; Bazin, Arnaud; Sherpereel, Bernard; Bernard, Marie Helene; Rousseaux, Pascal

    2009-07-15

    Purpose: We discuss our experiences with fractionated stereotactic radiotherapy (FSR) in the treatment of cavernous sinus meningiomas. Methods and Materials: From 1995 to 2006, we monitored 100 patients diagnosed with cavernous sinus meningiomas; 84 female and 16 male patients were included. The mean patient age was 56 years. The most common symptoms were a reduction in visual acuity (57%), diplopia (50%), exophthalmy (30%), and trigeminal neuralgia (34%). Surgery was initially performed on 26 patients. All patients were treated with FSR. A total of 45 Gy was administered to the lesion, with 5 fractions of 1.8 Gy completed each week. Patient treatment was performed using a Varian Clinac linear accelerator used for cranial treatments and a micro-multileaf collimator. Results: No side effects were reported. Mean follow-up period was 33 months, with 20% of patients undergoing follow-up evaluation of more than 4 years later. The tumor control rate at 3 years was 94%. Three patients required microsurgical intervention because FSR proved ineffective. In terms of functional symptoms, an 81% improvement was observed in patients suffering from exophthalmy, with 46% of these patients being restored to full health. A 52% improvement was observed in diplopia, together with a 67% improvement in visual acuity and a 50% improvement in type V neuropathy. Conclusions: FSR facilitates tumor control, either as an initial treatment option or in combination with microsurgery. In addition to being a safe procedure with few side effects, FSR offers the significant benefit of superior functional outcomes.

  12. Regional MLEM reconstruction strategy for PET-based treatment verification in ion beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Gianoli, Chiara; Bauer, Julia; Riboldi, Marco; De Bernardi, Elisabetta; Fattori, Giovanni; Baselli, Giuseppe; Debus, Jürgen; Parodi, Katia; Baroni, Guido

    2014-11-01

    In ion beam radiotherapy, PET-based treatment verification provides a consistency check of the delivered treatment with respect to a simulation based on the treatment planning. In this work the region-based MLEM reconstruction algorithm is proposed as a new evaluation strategy in PET-based treatment verification. The comparative evaluation is based on reconstructed PET images in selected regions, which are automatically identified on the expected PET images according to homogeneity in activity values. The strategy was tested on numerical and physical phantoms, simulating mismatches between the planned and measured β+ activity distributions. The region-based MLEM reconstruction was demonstrated to be robust against noise and the sensitivity of the strategy results were comparable to three voxel units, corresponding to 6 mm in numerical phantoms. The robustness of the region-based MLEM evaluation outperformed the voxel-based strategies. The potential of the proposed strategy was also retrospectively assessed on patient data and further clinical validation is envisioned.

  13. External beam radiotherapy as postoperative treatment of diffuse pigmented villonodular synovitis

    SciTech Connect

    Berger, Bernhard . E-mail: Bernhard.Berger@med.uni-tuebingen.de; Ganswindt, Ute; Bamberg, Michael; Hehr, Thomas

    2007-03-15

    Purpose: Diffuse pigmented villonodular synovitis is a rare proliferative disorder of synovial membranes with invasive and expansive growth patterns. Radical synovectomy is regarded as the treatment of choice. However, because of the high recurrence rates, additive treatment might be useful. Radiotherapy (RT) has been evaluated with positive results, but the optimal treatment schedules are vague. We have reviewed our experience with postoperative RT in cases of suspected or proven residual disease. Methods and Materials: Between December 1996 and January 2006, 7 diffuse pigmented villonodular synovitis patients underwent RT at our institution. The most common location was the knee joint (5 patients). All patients underwent radical surgery and were treated subsequently with 6-MV photon RT. The total doses applied were 30-50 Gy, depending on the resection status and estimated risk of relapse. For analysis, we retrospectively reviewed all patients in April 2006. Results: The mean follow-up time was 29 months (range, 3-112 months). RT had no acute adverse effects. At the assessment, no evidence was found of recurrent or persisting disease in any patient. Of the 7 patients, 6 reported asymptomatic limb function and excellent quality of life; 1 patient had persistent restriction of joint movement after repeated surgery. No radiotherapeutic late effects were seen. Conclusion: The results of our series have confirmed the efficacy and safety of postoperative RT for diffuse pigmented villonodular synovitis. Hence, this treatment should be considered for patients with suspected or proven residual disease.

  14. Malignant melanoma of the eye: treatment of posterior uveal lesions by Co-60 plaque radiotherapy versus enucleation

    SciTech Connect

    Markoe, A.M.; Brady, L.W. Jr.; Shields, J.A.; Augsburger, J.J.; Micaily, B.; Damsker, J.I.; Day, J.L.; Gamel, J.W.

    1985-09-01

    Survival rates and visual acuity of 100 patients treated for posterior uveal malignant melanoma by cobalt-60 plaque radiotherapy were compared with 150 patients treated by enucleation for the same disease. Life-table comparisons of the entire group showed significant differences in survival rates, with plaque radiotherapy patients appearing to fare better. However, when patients with small or medium tumors were compared, only slight differences were seen, implying that criteria used to select patients for treatment may affect interpretation. The two groups were also compared using the Cox proportional hazards model, which predicts survival based on the impact of clinical variables. In this analysis, the survival rates of the plaque radiotherapy group were no worse than those of the enucleation group. The advantage of conservative therapy lies in the potential to preserve useful vision over a considerable time.

  15. A technique using {sup 99m}Tc-mebrofenin SPECT for radiotherapy treatment planning for liver cancers or metastases

    SciTech Connect

    Shen, Sui; Jacob, Rojymon; Bender, Luvenia W.; Duan, Jun; Spencer, Sharon A.

    2014-04-01

    Radiotherapy or stereotactic body radiosurgery (SBRT) requires a sufficient functional liver volume to tolerate the treatment. The current study extended the work of de Graaf et al. (2010) [3] on the use of {sup 99m}Tc-mebrofenin imaging for presurgery planning to radiotherapy planning for liver cancer or metastases. Patient was immobilized and imaged in an identical position on a single-photon emission computed tomography/computed tomography (SPECT-CT) system and a radiotherapy simulation CT system. {sup 99m}Tc-mebrofenin SPECT was registered to the planning CT through image registration of noncontrast CT from SPECT-CT system to the radiotherapy planning CT. The voxels with higher uptake of {sup 99m}Tc-mebrofenin were transferred to the planning CT as an avoidance structure in optimizing a 2-arc RapidArc plan for SBRT delivery. Excellent dose coverage to the target and sparing of the healthy remnant liver volume was achieved. This report illustrated a procedure for the use of {sup 99m}Tc-mebrofenin SPECT for optimizing radiotherapy for liver cancers and metastases.

  16. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Thomas, T. Hannah Mary; Devakumar, D.; Purnima, S.; Ravindran, B. Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm × 10 cm beam at a gantry angle of 0° and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between ±6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  17. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning.

    PubMed

    Thomas, T Hannah Mary; Devakumar, D; Purnima, S; Ravindran, B Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm x 10 cm beam at a gantry angle of 0 degrees and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between +/-6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible. PMID:19287087

  18. FoCa: a modular treatment planning system for proton radiotherapy with research and educational purposes.

    PubMed

    Sánchez-Parcerisa, D; Kondrla, M; Shaindlin, A; Carabe, A

    2014-12-01

    FoCa is an in-house modular treatment planning system, developed entirely in MATLAB, which includes forward dose calculation of proton radiotherapy plans in both active and passive modalities as well as a generic optimization suite for inverse treatment planning. The software has a dual education and research purpose. From the educational point of view, it can be an invaluable teaching tool for educating medical physicists, showing the insights of a treatment planning system from a well-known and widely accessible software platform. From the research point of view, its current and potential uses range from the fast calculation of any physical, radiobiological or clinical quantity in a patient CT geometry, to the development of new treatment modalities not yet available in commercial treatment planning systems. The physical models in FoCa were compared with the commissioning data from our institution and show an excellent agreement in depth dose distributions and longitudinal and transversal fluence profiles for both passive scattering and active scanning modalities. 3D dose distributions in phantom and patient geometries were compared with a commercial treatment planning system, yielding a gamma-index pass rate of above 94% (using FoCa's most accurate algorithm) for all cases considered. Finally, the inverse treatment planning suite was used to produce the first prototype of intensity-modulated, passive-scattered proton therapy, using 13 passive scattering proton fields and multi-leaf modulation to produce a concave dose distribution on a cylindrical solid water phantom without any field-specific compensator. PMID:25387249

  19. FoCa: a modular treatment planning system for proton radiotherapy with research and educational purposes

    NASA Astrophysics Data System (ADS)

    Sánchez-Parcerisa, D.; Kondrla, M.; Shaindlin, A.; Carabe, A.

    2014-12-01

    FoCa is an in-house modular treatment planning system, developed entirely in MATLAB, which includes forward dose calculation of proton radiotherapy plans in both active and passive modalities as well as a generic optimization suite for inverse treatment planning. The software has a dual education and research purpose. From the educational point of view, it can be an invaluable teaching tool for educating medical physicists, showing the insights of a treatment planning system from a well-known and widely accessible software platform. From the research point of view, its current and potential uses range from the fast calculation of any physical, radiobiological or clinical quantity in a patient CT geometry, to the development of new treatment modalities not yet available in commercial treatment planning systems. The physical models in FoCa were compared with the commissioning data from our institution and show an excellent agreement in depth dose distributions and longitudinal and transversal fluence profiles for both passive scattering and active scanning modalities. 3D dose distributions in phantom and patient geometries were compared with a commercial treatment planning system, yielding a gamma-index pass rate of above 94% (using FoCa’s most accurate algorithm) for all cases considered. Finally, the inverse treatment planning suite was used to produce the first prototype of intensity-modulated, passive-scattered proton therapy, using 13 passive scattering proton fields and multi-leaf modulation to produce a concave dose distribution on a cylindrical solid water phantom without any field-specific compensator.

  20. Effects of postoperative adjuvant chemotherapy and radiotherapy on testicular function in men undergoing treatment for soft tissue sarcoma

    SciTech Connect

    Shamberger, R.C.; Sherins, R.J.; Rosenberg, S.A.

    1981-05-15

    Testicular function was studied in 26 men with sarcoma who received adjuvant treatment with doxorubicin, cyclophosphamide, and high-dose methotrexate (with or without radiotherapy). Testicular size, sperm output, and serum FSH, LH and testosterone levels were assessed after treatment. Five of 17 men who received chemotherapy or chemotherapy with radiotherapy to the neck, arm, chest or leg, had normal testicular function. Eight of the remaining 12 men who provided ejaculates were oligospermic or azoospermic and serum FSH was increased threefold and LH twofold; testosterone levels were normal. In men less than 40 years old, the mean FSH level was less than that of men over 40 years of age (P = 0.05), suggesting that recovery from the injury was age-related. By contrast, all nine men who received chemotherapy plus radiotherapy to the abdomen or thigh had decreased testicular size, azoospermia, fourfold increase in FSH, and twofold increase in LH levels; but testosterone concentration was normal. These data indicate that reversible testicular injury occurs after treatment with doxorubicin, cyclophosphamide, and high-dose methotrexate; recovery is age-related. However, these agents in combination with use of adjuvant radiotherapy to the thigh or abdomen may produce permanent testicular injury even in young patients.

  1. Usefulness of image morphing techniques in cancer treatment by conformal radiotherapy

    NASA Astrophysics Data System (ADS)

    Atoui, Hussein; Sarrut, David; Miguet, Serge

    2004-05-01

    Conformal radiotherapy is a cancer treatment technique, that targets high-energy X-rays to tumors with minimal exposure to surrounding healthy tissues. Irradiation ballistics is calculated based on an initial 3D Computerized Tomography (CT) scan. At every treatment session, the random positioning of the patient, compared to the reference position defined by the initial 3D CT scan, can generate treatment inaccuracies. Positioning errors potentially predispose to dangerous exposure to healthy tissues as well as insufficient irradiation to the tumor. A proposed solution would be the use of portal images generated by Electronic Portal Imaging Devices (EPID). Portal images (PI) allow a comparison with reference images retained by physicians, namely Digitally Reconstructed Radiographs (DRRs). At present, physicians must estimate patient positional errors by visual inspection. However, this may be inaccurate and consumes time. The automation of this task has been the subject of many researches. Unfortunately, the intensive use of DRRs and the high computing time required have prevented real time implementation. We are currently investigating a new method for DRR generation that calculates intermediate DRRs by 2D deformation of previously computed DRRs. We approach this investigation with the use of a morphing-based technique named mesh warping.

  2. Chemotherapy- and radiotherapy-induced oral mucositis: review of preventive strategies and treatment.

    PubMed

    Saadeh, Claire E

    2005-04-01

    Oral mucositis is a frequently encountered and potentially severe complication associated with administration of chemotherapy and radiotherapy. Although many pharmacologic interventions have been used for the prevention and treatment of oral mucositis, there is not one universally accepted strategy for its management. Most preventive and treatment strategies are based on limited, often anecdotal, clinical data. Basic oral hygiene and comprehensive patient education are important components of care for any patient with cancer at risk for development of oral mucositis. Nonpharmacologic approaches for the prevention of oral mucositis include oral cryotherapy for patients receiving chemotherapy with bolus 5-fluorouracil, and low-level laser therapy for patients undergoing hematopoietic stem cell transplantation. Chlorhexidine, amifostine, hematologic growth factors, pentoxifylline, glutamine, and several other agents have all been investigated for prevention of oral mucositis. Results have been conflicting, inconclusive, or of limited benefit. Treatment of established mucositis remains a challenge and focuses on a palliative management approach. Topical anesthetics, mixtures (also called cocktails), and mucosal coating agents have been used despite the lack of experimental evidence supporting their efficacy. Investigational agents are targeting the specific mechanisms of mucosal injury; among the most promising of these is recombinant human keratinocyte growth factor. PMID:15977916

  3. Investigation of patient, tumour and treatment variables affecting residual motion for respiratory-gated radiotherapy

    NASA Astrophysics Data System (ADS)

    George, R.; Ramakrishnan, V.; Siebers, J. V.; Chung, T. D.; Keall, P. J.

    2006-10-01

    Respiratory gating can reduce the apparent respiratory motion during imaging and treatment; however, residual motion within the gating window remains. Respiratory training can improve respiratory reproducibility and, therefore, the efficacy of respiratory-gated radiotherapy. This study was conducted to determine whether residual motion during respiratory gating is affected by patient, tumour or treatment characteristics. The specific aims of this study were to: (1) identify significant characteristics affecting residual motion, (2) investigate time trends of residual motion over a period of days (inter-session) and (3) investigate time trends of residual motion within the same day (intra-session). Twenty-four lung cancer patients were enrolled in an Institutional Review Board (IRB)-approved protocol. For approximately five sessions, 331 four-minute, respiratory motion traces were acquired with free breathing, audio instructions and audio-visual biofeedback for each patient. The residual motion was quantified by the standard deviation of the displacement within the gating window. The generalized linear model was used to obtain coefficients for each variable within the model and to evaluate the clinical and statistical significance. The statistical significance was determined by a p-value <0.05, while effect sizes of >=0.1 cm (one standard deviation) were considered clinically significant. This data analysis was applied to patient, tumour and treatment variables. Inter- and intra-session variations were also investigated. The only variable that was significant for both inhale- and exhale-based gating was disease type. In addition, visual-training displacement, breathing type and Karnofsky performance status (KPS) values were significant for inhale-based gating, and dose-per-fraction was significant for exhale-based gating. Temporal respiratory variations within and between sessions were observed for individual patients. However inter- and intra-session analyses did

  4. [Status report of Hungarian radiotherapy based on treatment data, available infrastucture, and human resources].

    PubMed

    Polgár, Csaba; Major, Tibor; Király, Réka; Fodor, János; Kásler, Miklós

    2015-06-01

    The purpose of the study is to report the status of Hungarian radiotherapy (RT) based on the assessment of treatment data in years 2012 to 2014, available infrastructure, and RT staffing. Between December 2014 and January 2015, a RT questionnaire including 3 parts (1. treatment data; 2. infrastructure; 3. staffing) was sent out to all Hungarian RT centers (n=12). All RT centers responded to all questions of the survey. 1. Treatment data: In 2014, 33,162 patients were treated with RT: 31,678 (95.5%) with teletherapy, and 1484 (4.5%) with brachytherapy (BT). Between 2012 and 2014, the number of patients treated with radiotherapy increased with 6.6%, but the number of BT patients decreased by 11%. Forty-two percent of all patients were treated in the two centers of the capital: 9235 patients (28%) at the National Institute of Oncology (NIO), and 4812 (14%) at the Municipial Oncoradiology Center (MOC). Out of the patients treated on megavoltage RT units (n=22,239), only 901 (4%) were treated with intensity-modulated RT (IMRT), and 2018 (9%) with image-guided RT (IGRT). In 2014, 52% of all BT treatments were performed in Budapest: NIO - 539 patients (36%); MOC - 239 patients (16%); and BT was not available in 3 RT centers. Prostate I-125 seed implants and interstitial breast BT was utilized in one, prostate HDR BT in two, and head&neck implants in three centers. 2. Infrastructure: Including ongoing development projects funded by the European Union, by the end of year 2015, 39 megavoltage teletherapy units, and 12 HDR BT units will be in use in 13 available Hungarian RT centers. 3. Staffing: Actually, 92 radiation oncologists (RO), 29 RT residents, 61 medical physicists, and 229 radiation therapy technologists are working in 12 RT centers. There are 23 vacant positions (including 11 RO positions) available at the Hungarian RT centers. According to the professional minimal requirements and WHO guidelines, the implementation of 11 new linear accelerators, and 1 BT units

  5. Postoperative Radiotherapy for Maxillary Sinus Cancer: Long-Term Outcomes and Toxicities of Treatment

    SciTech Connect

    Bristol, Ian J. . E-mail: ijbristol@mdanderson.org; Ahamad, Anesa; Garden, Adam S.; Morrison, William H.; Hanna, Ehab Y.; Papadimitrakopoulou, Vassiliki A.; Rosenthal, David I.; Ang, K. Kian

    2007-07-01

    Purpose: To determine the effects of three changes in radiotherapy technique on the outcomes for patients irradiated postoperatively for maxillary sinus cancer. Methods and Materials: The data of 146 patients treated between 1969 and 2002 were reviewed. The patients were separated into two groups according to the date of treatment. Group 1 included 90 patients treated before 1991 and Group 2 included 56 patients treated after 1991, when the three changes were implemented. The outcomes were compared between the two groups. Results: No differences were found in the 5-year overall survival, recurrence-free survival, local control, nodal control, or distant metastasis rates between the two groups (51% vs. 62%, 51% vs. 57%, 76% vs. 70%, 82% vs. 83%, and 28% vs. 17% for Groups 1 and 2, respectively). The three changes were to increase the portals to cover the base of the skull in patients with perineural invasion, reducing their risk of local recurrence; the addition of elective neck irradiation in patients with squamous or undifferentiated histologic features, improving the nodal control, distant metastasis, and recurrence-free survival rates (64% vs. 93%, 20% vs. 3%, and 45% vs. 67%, respectively; p < 0.05 for all comparisons); and improving the dose distributions within the target volume, reducing the late Grade 3-4 complication rates (34% in Group 1 vs. 8% in Group 2, p = 0.014). Multivariate analysis revealed advancing age, the need for enucleation, and positive margins as independent predictors of worse overall survival. The need for enucleation also predicted for worse local control. Conclusion: The three changes in radiotherapy technique improved the outcomes for select patients as predicted. Despite these changes, little demonstrable overall improvement occurred in local control or survival for these patients and additional work must be done.

  6. PSA Decrease During Combined-Modality Radiotherapy Predicts for Treatment Outcome

    SciTech Connect

    Kubicek, Gregory J.; Naguib, Marco; Redfield, Sandy; Grayback, Nola; Olszanski, Arthur; Dawson, George; Brown, Sam I.

    2010-11-01

    Purpose: Prostate-specific antigen (PSA) is the well-used marker in the diagnosis, prognosis, and follow-up for prostate cancer patients. Although reports have focused on the importance of pretreatment PSA levels, doubling time, and posttreatment nadirs, there is little information on the value of PSA during the course of radiotherapy. Methods and Materials: Retrospective review of PSA values obtained midway through a course of radiotherapy treatment for prostate cancer. Patients had a PSA (midPSA) measured after a course of external beam radiation (EBRT) before planned transperineal low-dose-rate brachytherapy implant (LDR). Results: A total of 717 patients were analyzed with a median follow-up of 5.8 years, all censored patients had a minimum follow-up of 2 years. A total of 277 patients had low-risk disease, 267 patients had intermediate risk, and 173 patients had high-risk disease. Androgen blockade was used in 512 patients. A total of 653 patients had a midPSA decrease after EBRT, the median decrease was 6.2 ng/mL. Patients who had a midPSA decrease {>=}25% compared with pretreatment PSA had improved overall survival of 10.0 vs. 7.4 years (p < 0.0004) and improved disease-free survival of 9.8 vs. 7.3 years (p < 0.01). When stratified by use of androgen blockade, midPSA remained significant for both androgen and non-androgen patients. Conclusions: PSA response after EBRT before brachytherapy predicts for long-term outcome; this may allow for risk stratification and intervention with higher LDR doses to improve outcomes.

  7. Raw liquid waste treatment process

    NASA Technical Reports Server (NTRS)

    Humphrey, Marshall F. (Inventor)

    1980-01-01

    A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, which is suspended in the sewage water is first separated from the water, in which at least organic matter is dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material absorbs organic matter and heavy metal ions, it is believed, are dissolved in the water and is thereafter supplied in a counter current flow direction and combined with the incoming raw sewage to facilitate the separation of the non-dissolved settleable materials from the sewage water. The used carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

  8. Full-dose capecitabine with local radiotherapy: one of the treatment options for inoperable T4 breast cancer.

    PubMed

    Hirowatari, Hisako; Karasawa, Kumiko; Izawa, Hiromi; Ito, Kana; Sasai, Keisuke; Furuya, Tomohisa; Ozawa, Shuichi; Arakawa, Atsushi; Orihata, Gotaro; Saito, Mitsue

    2011-04-01

    A 48-year-old woman presented with a 15-cm diameter tumor in her left breast with fixation to the chest wall and palpable axillary lymph nodes. Pathology study showed pure-type mucinous carcinoma. Pretreatment staging investigations showed multiple lung metastases, which resulted in the diagnosis of T4N2M1 breast cancer. Four cycles of cyclophosphamide 700 mg/m(2)/epirubicin 70 mg/m(2) (CE) were performed initially, but the tumors decreased only within the treatment response criteria of stable disease (SD). The second regimen of docetaxel could not continue due to drug allergy. Two more cycles of CE did not improve the situation. Then, treatment was continued with full-dose capecitabine with local radiotherapy. She received radiotherapy to the left breast and axillary region with 60 Gy/30 fractions/6 weeks and concomitant capecitabine 2400 mg/body twice daily for 21 days; the cycles were repeated every 28 days. After radiotherapy, tumors decreased in size, and the skin ulceration disappeared. She continued to receive capecitabine on the same schedule. She now has no palpable tumor in her left breast and no tumor in the axilla or lung on CT. She is alive and well 6 years after radiotherapy. PMID:21519998

  9. Proton Radiotherapy for Prostate Cancer Is Not Associated With Post-Treatment Testosterone Suppression

    SciTech Connect

    Nichols, R. Charles; Morris, Christopher G.; Hoppe, Bradford S.; Henderson, Randal H.; Marcus, Robert B.; Mendenhall, William M.; Li Zuofeng; Williams, Christopher R.; Costa, Joseph A.; Mendenhall, Nancy P.

    2012-03-01

    Purpose: Three independent studies of photon (x-ray) radiotherapy (RT) for prostate cancer have demonstrated evidence of testosterone suppression after treatment. The present study was undertaken to determine whether this would also be the case with conformal protons. Methods and Materials: Between August 2006 and October 2007, 171 patients with low- and intermediate-risk prostate cancer were enrolled and underwent treatment according to University of Florida Proton Therapy Institute institutional review board-approved PR01 and PR02 protocols. Of the 171 patients, 18 were excluded because they had received androgen deprivation therapy either before (n = 17) or after (n = 1) RT. The pretreatment serum testosterone level was available for 150 of the remaining 153 patients. These 150 patients were included in the present study. The post-treatment levels were compared with the pretreatment levels. Results: The median baseline pretreatment serum testosterone level was 357.9 ng/dL. The median post-treatment testosterone value was 375.5 ng/dL at treatment completion (p = .1935) and 369.9 ng/dL (p = .1336), 348.7 ng/dL (p = .7317), 353.4 ng/dL (p = .6996), and 340.9 ng/dL (p = .1669) at 6, 12, 18, and 24 months after proton therapy, respectively. Conclusions: Conformal proton therapy to the prostate, as delivered using University of Florida Proton Therapy Institute PR01 and PR02 protocols, did not appear to significantly affect the serum testosterone levels within 24 months after RT.

  10. A DVH-guided IMRT optimization algorithm for automatic treatment planning and adaptive radiotherapy replanning

    SciTech Connect

    Zarepisheh, Masoud; Li, Nan; Long, Troy; Romeijn, H. Edwin; Tian, Zhen; Jia, Xun; Jiang, Steve B.

    2014-06-15

    Purpose: To develop a novel algorithm that incorporates prior treatment knowledge into intensity modulated radiation therapy optimization to facilitate automatic treatment planning and adaptive radiotherapy (ART) replanning. Methods: The algorithm automatically creates a treatment plan guided by the DVH curves of a reference plan that contains information on the clinician-approved dose-volume trade-offs among different targets/organs and among different portions of a DVH curve for an organ. In ART, the reference plan is the initial plan for the same patient, while for automatic treatment planning the reference plan is selected from a library of clinically approved and delivered plans of previously treated patients with similar medical conditions and geometry. The proposed algorithm employs a voxel-based optimization model and navigates the large voxel-based Pareto surface. The voxel weights are iteratively adjusted to approach a plan that is similar to the reference plan in terms of the DVHs. If the reference plan is feasible but not Pareto optimal, the algorithm generates a Pareto optimal plan with the DVHs better than the reference ones. If the reference plan is too restricting for the new geometry, the algorithm generates a Pareto plan with DVHs close to the reference ones. In both cases, the new plans have similar DVH trade-offs as the reference plans. Results: The algorithm was tested using three patient cases and found to be able to automatically adjust the voxel-weighting factors in order to generate a Pareto plan with similar DVH trade-offs as the reference plan. The algorithm has also been implemented on a GPU for high efficiency. Conclusions: A novel prior-knowledge-based optimization algorithm has been developed that automatically adjust the voxel weights and generate a clinical optimal plan at high efficiency. It is found that the new algorithm can significantly improve the plan quality and planning efficiency in ART replanning and automatic treatment

  11. The Role of Radiotherapy in the Treatment of Primary or Recurrent Desmoid Tumors and Long-Term Results

    PubMed Central

    Ergen, Şefika Arzu; Tiken, Elif Eda; Öksüz, Didem Çolpan; Dinçbaş, Fazilet Öner; Dervişoğlu, Sergülen; Mandel, Nil Molinas; Hız, Murat; Koca, Sedat

    2016-01-01

    Background: Desmoid tumors are uncommon and benign mesenchymal neoplasms. The optimal treatment of patients with desmoid tumors is still controversial. Surgery is the primary treatment for locally invasive or recurrent desmoid tumors. Also, radiotherapy is a treatment option for patients at high risk for local failure such as those with positive margins or recurrent and unresectable tumors. Aims: To report our institutional experience and long-term results of patients with desmoid tumors who received radiotherapy. Study Design: Retrospective cross-sectional study. Methods: Between 1980 and 2009, 20 patients who received radiotherapy (RT) in our institution were analyzed. The majority of patients (80%) were referred with a recurrent tumor after previous surgery. Thirteen patients underwent marginal resection, 4 had wide local excision and 3 patients had only biopsy. Resection margin was positive in 15 (75%) patients. All patients received radiation therapy. The median prescribed dose was 60 Gy. Five patients received less than 54 Gy. Results: The median follow-up time was 77.5 months (28–283 months). Nine patients developed local recurrence after RT. Seven local failures (78%) were in field. Time to local recurrence ranged from 3–165 months (median 33 months). The 2–5 year local control (LC) rates were 80% and 69%, respectively. On univariate analysis, the 5 year local control rate was significantly better in the patients treated with ≥54 Gy than in patients who received <54 Gy (p=0.023). The most common acute side effect was grade 1–2 skin toxicity. As a late side effect of radiotherapy, soft tissue fibrosis was detected in 10 patients and lymphangitis was seen in 1 patient. One patient developed radiation-induced sarcoma. Conclusion: According to our results, radiotherapy is especially effective in recurrent disease and provides a high local control rate in the patients received more than 54 Gy. PMID:27308076

  12. Dosimetry characterization of a multibeam radiotherapy treatment for age-related macular degeneration

    SciTech Connect

    Lee, Choonsik; Chell, Erik; Gertner, Michael; Hansen, Steven; Howell, Roger W.; Hanlon, Justin; Bolch, Wesley E.

    2008-11-15

    Age-related macular degeneration (ARMD) is a major health problem worldwide. Advanced ARMD, which ultimately leads to profound vision loss, has dry and wet forms, which account for 20% and 80% of cases involving severe vision loss, respectively. A new device and approach for radiation treatment of ARMD has been recently developed by Oraya Therapeutics, Inc. (Newark, CA). The goal of the present study is to provide a initial dosimetry characterization of the proposed radiotherapy treatment via Monte Carlo radiation transport simulation. A 3D eye model including cornea, anterior chamber, lens, orbit, fat, sclera, choroid, retina, vitreous, macula, and optic nerve was carefully designed. The eye model was imported into the MCNPX2.5 Monte Carlo code and radiation transport simulations were undertaken to obtain absorbed doses and dose volume histograms (DVH) to targeted and nontargeted structures within the eye. Three different studies were undertaken to investigate (1) available beam angles that maximized the dose to the macula target tissue, simultaneously minimizing dose to normal tissues, (2) the energy dependency of the DVH for different x-ray energies (80, 100, and 120 kVp), and (3) the optimal focal spot size among options of 0.0, 0.4, 1.0, and 5.5 mm. All results were scaled to give 8 Gy to the macula volume, which is the current treatment requirement. Eight beam treatment angles are currently under investigation. In all eight beam angles, the source-to-target distance is 13 cm, and the polar angle of entry is 30 degree sign from the geometric axis of the eye. The azimuthal angle changes in eight increments of 45 degree sign in a clockwise fashion, such that an azimuthal angle of 0 degree sign corresponds to the 12 o'clock position when viewing the treated eye. Based on considerations of nontarget tissue avoidance, as well as facial-anatomical restrictions on beam delivery, treatment azimuthal angles between 135 degree sign and 225 degree sign would be available

  13. Investigation of MR image distortion for radiotherapy treatment planning of prostate cancer

    NASA Astrophysics Data System (ADS)

    Chen, Z.; Ma, C.-M.; Paskalev, K.; Li, J.; Yang, J.; Richardson, T.; Palacio, L.; Xu, X.; Chen, L.

    2006-03-01

    MR imaging based treatment planning for radiotherapy of prostate cancer is limited due to MR imaging system related geometrical distortions, especially for patients with large body sizes. On our 0.23 T open scanner equipped with the gradient distortion correction (GDC) software, the residual image distortions after the GDC were <5 mm within the central 36 cm × 36 cm area for a standard 48 cm field of view (FOV). In order to use MR imaging alone for treatment planning the effect of residual MR distortions on external patient contour determination, especially for the peripheral regions outside the 36 cm × 36 cm area, must be investigated and corrected. In this work, we performed phantom measurements to quantify MR system related residual geometric distortions after the GDC and the effective FOV. Our results show that for patients with larger lateral dimensions (>36 cm), the differences in patient external contours between distortion-free CT images and GDC-corrected MR images were 1-2 cm because of the combination of greater gradient distortion and loss of field homogeneity away from the isocentre and the uncertainties in patient setup during CT and MRI scans. The measured distortion maps were used to perform point-by-point corrections for patients with large dimensions inside the effective FOV. Using the point-by-point method, the geometrical distortion after the GDC were reduced to <3 mm for external contour determination and the effective FOV was expanded from 36 cm to 42 cm.

  14. Intensity-Modulated Radiotherapy in Postoperative Treatment of Oral Cavity Cancers

    SciTech Connect

    Gomez, Daniel R. Zhung, Joanne E.; Gomez, Jennifer; Chan, Kelvin; Wu, Abraham J.; Wolden, Suzanne L.; Pfister, David G.; Shaha, Ashok; Shah, Jatin P.; Kraus, Dennis H.; Wong, Richard J.; Lee, Nancy Y.

    2009-03-15

    Purpose: To present our single-institution experience of intensity-modulated radiotherapy (IMRT) for oral cavity cancer. Methods and Materials: Between September 2000 and December 2006, 35 patients with histologically confirmed squamous cell carcinoma of the oral cavity underwent surgery followed by postoperative IMRT. The sites included were buccal mucosa in 8, oral tongue in 11, floor of the mouth in 9, gingiva in 4, hard palate in 2, and retromolar trigone in 1. Most patients had Stage III-IV disease (80%). Ten patients (29%) also received concurrent postoperative chemotherapy with IMRT. The median prescribed radiation dose was 60 Gy. Results: The median follow-up for surviving patients was 28.1 months (range, 11.9-85.1). Treatment failure occurred in 11 cases as follows: local in 4, regional in 2, and distant metastases in 5. Of the 5 patients with distant metastases, 2 presented with dermal metastases. The 2- and 3-year estimates of locoregional progression-free survival, distant metastasis-free survival, disease-free survival, and overall survival were 84% and 77%, 85% and 85%, 70% and 64%, and 74% and 74%, respectively. Acute Grade 2 or greater dermatitis, mucositis, and esophageal reactions were experienced by 54%, 66%, and 40% of the patients, respectively. Documented late complications included trismus (17%) and osteoradionecrosis (5%). Conclusion: IMRT as an adjuvant treatment after surgical resection for oral cavity tumors is feasible and effective, with promising results and acceptable toxicity.

  15. [Cryotherapy, combined drug therapy and radiotherapy in the treatment of oral cavity cancer: 3 years' experience].

    PubMed

    Vercellino, V; Goia, F; Gandolfo, S; Camoletto, D

    1980-01-01

    The medium-term (three years) result of a multidisciplinary association treatment of carcinoma of the oral cavity has been reviewed. Treatment was Cryosurgery-polychemotherapy-ratiotherapy and the technique has been described along with the times of association in an introduction that has already been published in this review (see bibliography). Thirty patients were treated with the association because they refused or could not be submitted to surgery at the intital therapeutic action. All these patients present fairly extensive lesions and a three-year follow-up. Results were positive: 56.6% of patients showed disappearance of any objective or subjective sign of cancer and, in all cases, appreciable remission in terms of both extent and duration. The easiness of the technique is confirmed as well as the excellent conversation of the anatomical structures involved. However, a critical review of cases presenting partial failure suggest a classifications of oral carcinomatous lesions (for therapeutic purposes only) on the basis of which the condition can be treated with cryo-polychemo-radiotherapy alone or with a variation of this which provides for the addition of local exersis. PMID:6935521

  16. Treatment and technical intervention time analysis of a robotic stereotactic radiotherapy system.

    PubMed

    Crop, F; Lacornerie, T; Szymczak, H; Felin, A; Bailleux, C; Mirabel, X; Lartigau, E

    2014-02-01

    The purpose of this study is to obtain a better operational knowledge of Stereotactic Body Radiotherapy (SBRT) treatments with CyberKnife(r). An analysis of both In-room Times (IRT) and technical interventions of 5 years of treatments was performed, during which more than 1600 patients were treated for various indications, including liver (21%), lung (29%), intracranial (13%), head and neck (11%) and prostate (7%). Technical interventions were recorded along with the time of the failure, time to the intervention, and the complexity and duration of the repair. Analyses of Time Between Failures (TBF) and Service Disrupting TBF(disr) were performed. Treatment time data and variability per indication and following different system upgrades were evaluated. Large variations of IRTs were found between indications, but also large variations for each indication. The combination of the time reduction Tool (using Iris(r)) and Improved Stop Handling was of major impact to shortening of treatment times. The first implementation of the Iris collimator alone did not lead to significantly shorter IRTs for us except during prostate treatments. This was mostly due to the addition at the same time of larger rotational compensation for prostate treatments (58 instead of 1.58). Significant differences of duration between the first fraction and following fractions of a treatment, representing the necessity of defining imaging parameters and explanation to patients, were found for liver (12 min) and lung treatments using Xsight(r) Spine (5 min). Liver and lung treatments represent the longest IRT's and involve the largest variability's in IRT. The malfunction rate of the system followed a Weibull distribution with the shape and scale parameters of 0.8 and 39.7. Mean TBF(disr) was 68 work hours. 60 to 80% of the service disrupting interventions were resolved within 30-60 min, 5% required external intervention and 30% occurred in the morning. The presented results can be applied in the

  17. [Stereotactic radiotherapy and radiosurgery in treatment of patients with intracranial schwannomas].

    PubMed

    Zolotova, S V; Golanov, A V; Kotel'nikova, T M; Soboleva, O I; Gorlachev, G E; Fil'chenkova, N A; Nikonova, N G; Kapitanov, D N; Makhmudov, U B; Shimanskiĭ, V N; Arutiunov, N V; Pronin, I N

    2010-01-01

    Aim of this study is to assess the role of stereotactic radiosurgery (SRS) and radiotherapy (SRT) in management of cranial nerves schwannomas by analysis of tumor control, clinical response and variables affecting treatment outcomes. Between April 2005 and January 2009 patients with schwannomas of VIII (63), V (14) and caudal nerves (2) were treated in Burdenko Moscow Neurosurgical Institute using linear accelerator. Mean age was 49 years (13-82). In 42 cases radiation treatment was preceded by surgical resection. 13 patients had type I or II neurofibromatosis. Mean volume of the tumor was 3.9 cm3 (0.5-14.4 cm3) and 13.4 cm3 (2.8-41.3 cm3) for SRS and SRT, respectively. Mean SRS dose was 12 Gy (10.8-14.4 Gy) for vestibular schwannomas and 15 Gy (13.2-18 Gy) for schwannomas of other nerves. In hypofractionated SRT the dose of 35 Gy was delivered in 7 fractions or 30 Gy in 6 fractions. In cases of classical fractioning total dose of 50-60 Gy was divided into daily fractions of 1.8-2.0 Gy. Radiographic tumor control rate reached 97.5% at the last follow-up. 5 patients experienced trigeminal dysfunction, it was transient in 3 cases and persistent in 2. Permanent decline in House-Brackmann facial nerve scale developed in 2 of 79 patients. After treatment effective hearing (class I-II) was preserved in 7 of 9 patients (67%) who had same level of hearing before SRS. Linear accelerator-based stereotactic radiation treatment provides long-term tumor control associated with high rates of preservation of neurological functions. No further tumor surgery was necessary in 100% of cases with solitary tumors with a minimal follow-up of 5 years. PMID:20429361

  18. Salvage Treatment With Hypofractionated Radiotherapy in Patients With Recurrent Small Hepatocellular Carcinoma

    SciTech Connect

    Bae, Sun Hyun; Park, Hee Chul; Lim, Do Hoon; Lee, Jung Ae; Gwak, Geum Yeon; Choi, Moon Seok; Lee, Joon Hyoek; Koh, Kwang Cheol; Paik, Seung Woon; Yoo, Byung Chul

    2012-03-15

    Purpose: To investigate the rates of tumor response and local control in patients with recurrent small hepatocellular carcinoma (HCC) treated with hypofractionated radiotherapy (RT) as a salvage treatment and to evaluate treatment-related toxicities. Methods and Materials: Between 2006 and 2009, a total of 20 patients with recurrent small HCC were treated with hypofractionated RT after the failure of previous treatment. The eligibility criteria for hypofractionated RT were as follows: 1) HCC less than 5 cm, 2) HCC not adjacent to critical organs, 3) HCC without portal vein tumor thrombosis, and 4) less than 15% of normal liver volume that would be irradiated with 50% of prescribed dose. The RT dose was 50 Gy in 10 fractions. The tumor response was determined by CT scans performed 3 months after the end of RT. Results: The median follow-up period after RT was 22 months. The overall survival rates at 1 and 2 years were 100% and 87.9%, respectively. Complete response (CR) was achieved in seven of 20 lesions (35%) evaluated by CT scans performed 3 months after the end of RT. In-field local control was achieved in 85% of patients. Fourteen patients (70%) developed intra-hepatic metastases. Six patients developed grade 1 nausea or anorexia during RT, and two patients had progression of ascites after RT. There was no grade 3 or greater treatment-related toxicities. Conclusions: The current study showed a favorable outcome with respect to hypofractionated RT for small HCC. Partial liver irradiation with 50 Gy in 10 fractions is considered tolerable without severe complications.

  19. Dosimetric impact of image artifact from a wide-bore CT scanner in radiotherapy treatment planning

    SciTech Connect

    Wu, Vincent; Podgorsak, Matthew B.; Tran, Tuan-Anh; Malhotra, Harish K.; Wang, Iris Z.

    2011-07-15

    Purpose: Traditional computed tomography (CT) units provide a maximum scan field-of-view (sFOV) diameter of 50 cm and a limited bore size, which cannot accommodate a large patient habitus or an extended simulation setup in radiation therapy (RT). Wide-bore CT scanners with increased bore size were developed to address these needs. Some scanners have the capacity to reconstruct the CT images at an extended FOV (eFOV), through data interpolation or extrapolation, using projection data acquired with a conventional sFOV. Objects that extend past the sFOV for eFOV reconstruction may generate image artifacts resulting from truncated projection data; this may distort CT numbers and structure contours in the region beyond the sFOV. The purpose of this study was to evaluate the dosimetric impact of image artifacts from eFOV reconstruction with a wide-bore CT scanner in radiotherapy (RT) treatment planning. Methods: Testing phantoms (i.e., a mini CT phantom with equivalent tissue inserts, a set of CT normal phantoms and anthropomorphic phantoms of the thorax and the pelvis) were used to evaluate eFOV artifacts. Reference baseline images of these phantoms were acquired with the phantom centrally positioned within the sFOV. For comparison, the phantoms were then shifted laterally and scanned partially outside the sFOV, but still within the eFOV. Treatment plans were generated for the thoracic and pelvic anthropomorphic phantoms utilizing the Eclipse treatment planning system (TPS) to study the potential effects of eFOV artifacts on dose calculations. All dose calculations of baseline and test treatment plans were carried out using the same MU. Results: Results show that both body contour and CT numbers are altered by image artifacts in eFOV reconstruction. CT number distortions of up to -356 HU for bone tissue and up to 323 HU for lung tissue were observed in the mini CT phantom. Results from the large body normal phantom, which is close to a clinical patient size, show

  20. Intensity-Modulated Radiotherapy Causes Fewer Side Effects than Three-Dimensional Conformal Radiotherapy When Used in Combination With Brachytherapy for the Treatment of Prostate Cancer

    SciTech Connect

    Forsythe, Kevin; Blacksburg, Seth; Stone, Nelson; Stock, Richard G.

    2012-06-01

    Purpose: To measure the benefits of intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) when used in combination with brachytherapy for the treatment of prostate cancer. Methods and Materials: We conducted a retrospective review of all patients with localized prostate cancer who received external-beam radiotherapy (EBRT) in combination with brachytherapy with at least 1 year follow-up (n = 812). Combination therapy consisted of {sup 103}Pd or {sup 125}I implant, followed by a course of EBRT. From 1993 to March 2003 521 patients were treated with 3D-CRT, and from April 2003 to March 2009 291 patients were treated with IMRT. Urinary symptoms were prospectively measured with the International Prostate Symptom Score questionnaire with a single quality of life (QOL) question; rectal bleeding was assessed per the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The Pearson {chi}{sup 2} test was used to compare toxicities experienced by patients who were treated with either IMRT or 3D-CRT. Logistic regression analyses were also performed to rule out possible confounding factors. Results: Within the first 3 months after treatment, patients treated with 3D-CRT scored their urinary symptoms as follows: 19% mild, 44% moderate, and 37% severe; patients treated with IMRT scored their urinary symptoms as follows: 36% mild, 47% moderate, and 17% severe (p < 0.001). The 3D-CRT patients rated their QOL as follows: 35% positive, 20% neutral, and 45% negative; IMRT patients rated their QOL as follows: 51% positive, 18% neutral, and 31% negative (p < 0.001). After 1 year of follow-up there was no longer any difference in urinary morbidity between the two groups. Logistic regression confirmed the differences in International Prostate Symptom Score and QOL in the acute setting (p < 0.001 for both). Grade {>=}2 rectal bleeding was reported by 11% of 3D

  1. SU-D-BRD-02: A Web-Based Image Processing and Plan Evaluation Platform (WIPPEP) for Future Cloud-Based Radiotherapy

    SciTech Connect

    Chai, X; Liu, L; Xing, L

    2014-06-01

    Purpose: Visualization and processing of medical images and radiation treatment plan evaluation have traditionally been constrained to local workstations with limited computation power and ability of data sharing and software update. We present a web-based image processing and planning evaluation platform (WIPPEP) for radiotherapy applications with high efficiency, ubiquitous web access, and real-time data sharing. Methods: This software platform consists of three parts: web server, image server and computation server. Each independent server communicates with each other through HTTP requests. The web server is the key component that provides visualizations and user interface through front-end web browsers and relay information to the backend to process user requests. The image server serves as a PACS system. The computation server performs the actual image processing and dose calculation. The web server backend is developed using Java Servlets and the frontend is developed using HTML5, Javascript, and jQuery. The image server is based on open source DCME4CHEE PACS system. The computation server can be written in any programming language as long as it can send/receive HTTP requests. Our computation server was implemented in Delphi, Python and PHP, which can process data directly or via a C++ program DLL. Results: This software platform is running on a 32-core CPU server virtually hosting the web server, image server, and computation servers separately. Users can visit our internal website with Chrome browser, select a specific patient, visualize image and RT structures belonging to this patient and perform image segmentation running Delphi computation server and Monte Carlo dose calculation on Python or PHP computation server. Conclusion: We have developed a webbased image processing and plan evaluation platform prototype for radiotherapy. This system has clearly demonstrated the feasibility of performing image processing and plan evaluation platform through a web

  2. Osseous oligometastases from thymic carcinoma: a case report suggesting the effectiveness of palliative-intent radiotherapy treatment

    PubMed Central

    Kashima, Jumpei; Horio, Hirotoshi; Okuma, Yusuke; Hosomi, Yukio; Hishima, Tsunekazu

    2016-01-01

    Background Oligometastasis, a recently proposed concept, is defined as an intermediate state of cancer, between localized and systemic disease, that may be well controlled by local ablative treatment. Thymic carcinoma is a rare cancer with a poor prognosis. A definitive management approach has yet to be confirmed by a high level of evidence. Case presentation We present the case of a 41-year-old female who underwent curative-intent surgery for a stage III squamous cell carcinoma of the thymus. Bone metastases were detected 1 year later by magnetic resonance imaging. These were treated with palliative-intent radiotherapy. Disease progression has not been observed in more than 15 years since the achievement of complete radiological remission. Conclusion The treatment outcomes in this and other reported cases suggest that some patients with oligometastatic thymic carcinoma may achieve prolonged survival or even cure with low-dose radiotherapy delivered to the metastases. PMID:27013896

  3. A dosimetric analysis of volumetric-modulated arc radiotherapy with jaw width restriction vs 7 field intensity-modulated radiotherapy for definitive treatment of cervical cancer

    PubMed Central

    Huang, B; Fang, Z; Huang, Y; Lin, P

    2014-01-01

    Objective: Radiation therapy treatment planning was performed to compare the dosimetric difference between volumetric-modulated arc radiotherapy (RapidArc™ v. 10; Varian® Medical Systems, Palo Alto, CA) and 7-field intensity-modulated radiotherapy (7f-IMRT) in the definitive treatment of cervical cancer. Methods: 13 patients with cervical cancer were enrolled in this study. Planning target volume (PTV) 50 and PTV60 were prescribed at a dose of 50 and 60 Gy in 28 fractions, respectively. The dose to the PTV60 was delivered as a simultaneous integrated boost to the pelvic lymph nodes. Owing to the mechanical limitation of the multileaf collimator in which the maximum displacement was limited to 15 cm, two types of RapidArc with different jaw width restrictions (15 and 20–23 cm) were investigated to evaluate their dosimetric differences. The RapidArc plan type with dosimetric superiority was then compared against the 7f-IMRT on the target coverage, sparing of the organs at risk (OARs), monitor units, treatment time and delivery accuracy to determine whether RapidArc is beneficial for the treatment of cervical cancer. Results: The 15-cm jaw width restriction had better performance compared with the restrictions that were longer than 15 cm in the sparing of the OARs. The 15-cm RapidArc spared the OARs, that is, the bladder, rectum, small intestine, femoral heads and bones, and improved treatment efficiency compared with 7f-IMRT. Both techniques delivered a high quality-assurance passing rate (>90%) according to the Γ3mm,3% criterion. Conclusion: RapidArc with a 15-cm jaw width restriction spares the OARs and improves treatment efficiency in cervical cancer compared with 7f-IMRT. Advances in knowledge: This study describes the dosimetric superiority of RapidArc with a 15-cm jaw width restriction and explores the feasibility of using RapidArc for the definitive treatment of cervical cancer. PMID:24834477

  4. Silicon strip detector for a novel 2D dosimetric method for radiotherapy treatment verification

    NASA Astrophysics Data System (ADS)

    Bocci, A.; Cortés-Giraldo, M. A.; Gallardo, M. I.; Espino, J. M.; Arráns, R.; Alvarez, M. A. G.; Abou-Haïdar, Z.; Quesada, J. M.; Pérez Vega-Leal, A.; Pérez Nieto, F. J.

    2012-05-01

    The aim of this work is to characterize a silicon strip detector and its associated data acquisition system, based on discrete electronics, to obtain in a near future absorbed dose maps in axial planes for complex radiotherapy treatments, using a novel technique. The experimental setup is based on two phantom prototypes: the first one is a polyethylene slab phantom used to characterize the detector in terms of linearity, percent depth dose, reproducibility, uniformity and penumbra. The second one is a cylindrical phantom, specifically designed and built to recreate conditions close to those normally found in clinical environments, for treatment planning assessment. This system has been used to study the dosimetric response of the detector, in the axial plane of the phantom, as a function of its angle with respect to the irradiation beam. A software has been developed to operate the rotation of this phantom and to acquire signals from the silicon strip detector. As an innovation, the detector was positioned inside the cylindrical phantom parallel to the beam axis. Irradiation experiments were carried out with a Siemens PRIMUS linac operating in the 6 MV photon mode at the Virgen Macarena Hospital. Monte Carlo simulations were performed using Geant4 toolkit and results were compared to Treatment Planning System (TPS) calculations for the absorbed dose-to-water case. Geant4 simulations were used to estimate the sensitivity of the detector in different experimental configurations, in relation to the absorbed dose in each strip. A final calibration of the detector in this clinical setup was obtained by comparing experimental data with TPS calculations.

  5. Clinical Outcome of Adjuvant Treatment of Endometrial Cancer Using Aperture-Based Intensity-Modulated Radiotherapy

    SciTech Connect

    Bouchard, Myriam; Nadeau, Sylvain M.Sc.; Gingras, Luc; Raymond, Paul-Emile; Beaulieu, Frederic; Beaulieu, Luc; Fortin, Andre; Germain, Isabelle

    2008-08-01

    Purpose: To assess disease control and acute and chronic toxicity with aperture-based intensity-modulated radiotherapy (AB-IMRT) for postoperative pelvic irradiation of endometrial cancer. Methods and Materials: Between January and July 2005, after hysterectomy for endometrial cancer, 15 patients received 45 Gy to the pelvis using AB-IMRT. The AB-IMRT plans were generated by an in-house treatment planning system (Ballista). The AB-IMRT plans were used for treatment and were dosimetrically compared with three other approaches: conventional four-field, enlarged four-field, and beamlet-based IMRT (BB-IMRT). Disease control and toxicity were prospectively recorded and compared with retrospective data from 30 patients treated with a conventional four-field technique. Results: At a median follow-up of 27 months (range, 23-30), no relapse was noted among the AB-IMRT group compared with five relapses in the control group (p = 0.1). The characteristics of each group were similar, except for the mean body mass index, timing of brachytherapy, and applicator type used. Patients treated with AB-IMRT experienced more frequent Grade 2 or greater gastrointestinal acute toxicity (87% vs. 53%, p 0.02). No statistically significant difference was noted between the two groups regarding the incidence or severity of chronic toxicities. AB-IMRT plans significantly improved target coverage (93% vs. 76% of planning target volume receiving 45 Gy for AB-IMRT vs. conventional four-field technique, respectively). The sparing of organs at risk was similar to that of BB-IMRT. Conclusion: The results of our study have shown that AB-IMRT provides excellent disease control with equivalent late toxicity compared with the conventional four-field technique. AB-IMRT provided treatment delivery and quality assurance advantages compared with BB-IMRT and could reduce the risk of second malignancy compared with BB-IMRT.

  6. The Impact of Radiotherapy Fields in the Treatment of Patients With Choroid Plexus Carcinoma

    SciTech Connect

    Mazloom, Ali; Wolff, Johannes E.; Paulino, Arnold C.

    2010-09-01

    Purpose: To perform a comprehensive literature review and analysis of cases dealing with choroid plexus carcinoma (CPC) to determine the optimal radiotherapy (RT) treatment field. Methods and Materials: A PubMed search of English language articles from 1979 to 2008 was performed, yielding 33 articles with 56 patients who had available data regarding RT treatment field. The median age at diagnosis was 2.7 years (range, 1 month-53 years). Of 54 patients with data regarding type of surgery, 21 (38.9%) had complete resection. Chemotherapy was delivered to 27 (48%) as part of initial therapy. The RT treatment volume was the craniospinal axis in 38 (68%), whole brain in 9 (16%), and tumor/tumor bed in 9 (16%). Median follow-up for surviving patients was 40 months. Results: The 5-year overall survival and progression-free survival (PFS) rates were 59.5% and 37.2%, respectively. Complete resection (p = 0.035) and use of craniospinal irradiation (CSI; p = 0.025) were found to positively affect PFS. The 5-year PFS for patients who had CSI vs. whole brain and tumor/tumor bed RT were 44.2% and 15.3%. For the 19 patients who relapsed, 9 (47%) had a recurrence in the RT field, 6 (32%) had a recurrence outside the RT field, and 4 (21%) had a recurrence inside and outside the irradiated field. Conclusion: Patients with CPC who received CSI had better PFS compared with those receiving less than CSI. This study supports the use of CSI in the multimodality management of patients with CPC.

  7. Proton Radiotherapy: The Biological Effect of Treating Alternating Subsets of Fields for Different Treatment Fractions

    SciTech Connect

    Engelsman, Martijn; DeLaney, Thomas F.; Hong, Theodore S.

    2011-02-01

    Purpose: Common practice in proton radiotherapy is to deliver a subset of all fields in the treatment plan on any given treatment day. We investigate using biological modeling if the resulting variation in daily dose to normal tissues has a relevant detrimental biological effect. Methods and Materials: For four patient groups, the cumulative normalized total dose (NTD) was determined for normal tissues (OARs) of each patient using the clinically delivered fractionation schedule (FS{sub clin}), and for hypothetical fractionation schedules delivering all fields every day (FS{sub all}) or only a single field each day (FS{sub single}). Cumulative three-dimensional NTD distributions were summarized using the generalized equivalent uniform dose (gEUD) model. Results: For the skull base/cervical spine chordoma group, the largest effect is a 4-Gy increase in gEUD of the chiasm when treating only a subset of fields on any day. For lung cancer and pancreatic cancer patients, the variation in the gEUD of normal tissues is <0.2 Gy. For the prostate group, FS{sub clin} increases the gEUD of the femoral heads by 9 Gy compared with FS{sub all}. Use of FS{sub single} resulted in the highest NTD to normal tissues for any patient. FS{sub all} resulted in an integral NTD to the patient that is on average 5% lower than FS{sub clin} and 10% lower than FS{sub single}. Conclusion: The effects of field set of the day treatment delivery depend on the tumor site and number of fields treated each day. Modeling these effects may be important for accurate risk assessment.

  8. Reinforcing of QA/QC programs in radiotherapy departments in Croatia: Results of treatment planning system verification

    SciTech Connect

    Jurković, Slaven; Švabić, Manda; Diklić, Ana; Smilović Radojčić, Đeni; Dundara, Dea; Kasabašić, Mladen; Ivković, Ana; Faj, Dario

    2013-04-01

    Implementation of advanced techniques in clinical practice can greatly improve the outcome of radiation therapy, but it also makes the process much more complex with a lot of room for errors. An important part of the quality assurance program is verification of treatment planning system (TPS). Dosimetric verifications in anthropomorphic phantom were performed in 4 centers where new systems were installed. A total of 14 tests for 2 photon energies and multigrid superposition algorithms were conducted using the CMS XiO TPS. Evaluation criteria as specified in the International Atomic Energy Agency Technical Reports Series (IAEA TRS) 430 were employed. Results of measurements are grouped according to the placement of the measuring point and the beam energy. The majority of differences between calculated and measured doses in the water-equivalent part of the phantom were in tolerance. Significantly more out-of-tolerance values were observed in “nonwater-equivalent” parts of the phantom, especially for higher-energy photon beams. This survey was done as a part of continuous effort to build up awareness of quality assurance/quality control (QA/QC) importance in the Croatian radiotherapy community. Understanding the limitations of different parts of the various systems used in radiation therapy can systematically improve quality as well.

  9. Reinforcing of QA/QC programs in radiotherapy departments in Croatia: results of treatment planning system verification.

    PubMed

    Jurković, Slaven; Svabić, Manda; Diklić, Ana; Smilović Radojčić, Deni; Dundara, Dea; Kasabašić, Mladen; Ivković, Ana; Faj, Dario

    2013-01-01

    Implementation of advanced techniques in clinical practice can greatly improve the outcome of radiation therapy, but it also makes the process much more complex with a lot of room for errors. An important part of the quality assurance program is verification of treatment planning system (TPS). Dosimetric verifications in anthropomorphic phantom were performed in 4 centers where new systems were installed. A total of 14 tests for 2 photon energies and multigrid superposition algorithms were conducted using the CMS XiO TPS. Evaluation criteria as specified in the International Atomic Energy Agency Technical Reports Series (IAEA TRS) 430 were employed. Results of measurements are grouped according to the placement of the measuring point and the beam energy. The majority of differences between calculated and measured doses in the water-equivalent part of the phantom were in tolerance. Significantly more out-of-tolerance values were observed in "nonwater-equivalent" parts of the phantom, especially for higher-energy photon beams. This survey was done as a part of continuous effort to build up awareness of quality assurance/quality control (QA/QC) importance in the Croatian radiotherapy community. Understanding the limitations of different parts of the various systems used in radiation therapy can systematically improve quality as well. PMID:23246197

  10. Long-term cardiac sequelae after treatment of malignant tumors with radiotherapy or cytostatics in childhood

    SciTech Connect

    Maekinen, L.M.; Maekipernaa, A.R.; Rautonen, J.; Heino, M.; Pyrhoenen, S.L.; Laitinen, L.A.; Siimes, M.A. )

    1990-05-01

    A series of 41 individuals were restudied after childhood cancer with a median follow-up time of 17 years after chest irradiation or treatment with cyclophosphamide or Adriamycin (doxorubicin). Radiotherapy of the chest had been used in 21 patients, and in 13 of these irradiation was also directed at the heart. Thirty-five patients received cyclophosphamide and five received Adriamycin therapy. All patients were investigated by a pediatric cardiologist. Investigations included an electrocardiogram (ECG), a chest radiographic film, an echocardiogram, an exercise test, and a 24-hour ECG. Altogether 20 patients (49%) showed some abnormality in cardiac tests. Each additional year of follow-up was associated with a 1.3-fold (95% confidence limits, 1.04-1.66; P less than 0.05) increase in the risk for pathologic cardiac findings. The risk for an abnormal cardiac test result in the 13 patients who had received cardiac irradiation was 12.8-fold (95% confidence limits, 1.8-90.8; P less than 0.02) that of the other patients. However, abnormalities in cardiac function were mild.

  11. Modeling the Interplay Between Tumor Volume Regression and Oxygenation in Uterine Cervical Cancer During Radiotherapy Treatment.

    PubMed

    Belfatto, Antonella; Riboldi, Marco; Ciardo, Delia; Cattani, Federica; Cecconi, Agnese; Lazzari, Roberta; Jereczek-Fossa, Barbara Alicja; Orecchia, Roberto; Baroni, Guido; Cerveri, Pietro

    2016-03-01

    This paper describes a patient-specific mathematical model to predict the evolution of uterine cervical tumors at a macroscopic scale, during fractionated external radiotherapy. The model provides estimates of tumor regrowth and dead-cell reabsorption, incorporating the interplay between tumor regression rate and radiosensitivity, as a function of the tumor oxygenation level. Model parameters were estimated by minimizing the difference between predicted and measured tumor volumes, these latter being obtained from a set of 154 serial cone-beam computed tomography scans acquired on 16 patients along the course of the therapy. The model stratified patients according to two different estimated dynamics of dead-cell removal and to the predicted initial value of the tumor oxygenation. The comparison with a simpler model demonstrated an improvement in fitting properties of this approach (fitting error average value <5%, p < 0.01), especially in case of tumor late responses, which can hardly be handled by models entailing a constant radiosensitivity, failing to model changes from initial severe hypoxia to aerobic conditions during the treatment course. The model predictive capabilities suggest the need of clustering patients accounting for cancer cell line, tumor staging, as well as microenvironment conditions (e.g., oxygenation level). PMID:25647734

  12. A Phase I study of concurrent radiotherapy and capecitabine as adjuvant treatment for operable rectal cancer

    SciTech Connect

    Jin Jing

    2006-03-01

    Purpose: To determine the maximum tolerated dose and the dose-limiting toxicity of capecitabine with standard radiotherapy (RT) as adjuvant treatment in patients with rectal cancer. Methods and Materials: Patients with Stage II/III rectal cancer after surgery were eligible. Total RT dose was delivered as DT 50 Gy in fractions of 2.0 Gy/day for 5 weeks to the pelvic area. Capecitabine was administered concurrently with RT in escalating doses, twice daily with a 12-h interval, for two cycles of 14 days separated by a 7-day rest. Dose-limiting toxicity included Grade 3 or Grade 4 hematologic and nonhematologic toxicity. Results: Twenty-four patients were enrolled at the following dose levels: 1,000 (3 patients), 1,200 (3 patients), 1,400 (3 patients), 1,500 (3 patients), 1,600 (6 patients), and 1,700 mg/m{sup 2}/day (6 patients). Dose-limiting toxicity was observed in 1 patient at 1,600 mg/m{sup 2}/day (Grade 3 diarrhea) and in 2 patients at 1,700 mg/m{sup 2}/day (1 patient had Grade 3 and 1 Grade 4 diarrhea). Conclusion: The maximum tolerated dose (MTD) of capecitabine given concurrently with RT was 1,600 mg/m{sup 2}, daily from the 1st to the 14th day, with a 7-day rest, for two cycles.

  13. Impact of the accuracy of automatic tumour functional volume delineation on radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Le Maitre, Amandine; Hatt, Mathieu; Pradier, Olivier; Cheze-le Rest, Catherine; Visvikis, Dimitris

    2012-09-01

    Over the past few years several automatic and semi-automatic PET segmentation methods for target volume definition in radiotherapy have been proposed. The objective of this study is to compare different methods in terms of dosimetry. For such a comparison, a gold standard is needed. For this purpose, realistic GATE-simulated PET images were used. Three lung cases and three H&N cases were designed with various shapes, contrasts and heterogeneities. Four different segmentation approaches were compared: fixed and adaptive thresholds, a fuzzy C-mean and the fuzzy locally adaptive Bayesian method. For each of these target volumes, an IMRT treatment plan was defined. The different algorithms and resulting plans were compared in terms of segmentation errors and ground-truth volume coverage using different metrics (V95, D95, homogeneity index and conformity index). The major differences between the threshold-based methods and automatic methods occurred in the most heterogeneous cases. Within the two groups, the major differences occurred for low contrast cases. For homogeneous cases, equivalent ground-truth volume coverage was observed for all methods but for more heterogeneous cases, significantly lower coverage was observed for threshold-based methods. Our study demonstrates that significant dosimetry errors can be avoided by using more advanced image-segmentation methods.

  14. A novel four-dimensional radiotherapy method for lung cancer: imaging, treatment planning and delivery

    NASA Astrophysics Data System (ADS)

    Alasti, H.; Cho, Y. B.; Vandermeer, A. D.; Abbas, A.; Norrlinger, B.; Shubbar, S.; Bezjak, A.

    2006-06-01

    We present treatment planning methods based on four-dimensional computed tomography (4D-CT) to incorporate tumour motion using (1) a static field and (2) a dynamic field. Static 4D fields are determined to include the target in all breathing phases, whereas dynamic 4D fields are determined to follow the shape of the tumour assessed from 4D-CT images with a dynamic weighting factor. The weighting factor selection depends on the reliability of patient breathing and limitations of the delivery system. The static 4D method is compared with our standard protocol for gross tumour volume (GTV) coverage, mean lung dose and V20. It was found that the GTV delineated on helical CT without incorporating breathing motion does not adequately represent the target compared to the GTV delineated from 4D-CT. Dosimetric analysis indicates that the static 4D-CT based technique results in a reduction of the mean lung dose compared with the standard protocol. Measurements on a moving phantom and simulations indicated that 4D radiotherapy (4D-RT) synchronized with respiration-induced motion further reduces mean lung dose and V20, and may allow safe application of dose escalation and CRT/IMRT. The motions of the chest cavity, tumour and thoracic structures of 24 lung cancer patients are also analysed.

  15. Gemstone spectral imaging: determination of CT to ED conversion curves for radiotherapy treatment planning.

    PubMed

    Yagi, Masashi; Ueguchi, Takashi; Koizumi, Masahiko; Ogata, Toshiyuki; Yamada, Sachiko; Takahashi, Yutaka; Sumida, Iori; Akino, Yuichi; Konishi, Koji; Isohashi, Fumiaki; Tomiyama, Noriyuki; Yoshioka, Yasuo; Ogawa, Kazuhiko

    2013-01-01

    The monochromatic images acquired by Gemstone spectral imaging (GSI) mode on the GE CT750 HD theoretically determines the computed tomography (CT) number more accurately than that of conventional scanner. Using the former, the CT number is calculated from (synthesized) monoenergetic X-ray data. We reasoned that the monochromatic image might be applied to radiotherapy treatment planning (RTP) to calculate dose distribution more accurately. Our goal here was to provide CT to electron density (ED) conversion curves with monochromatic images for RTP. Therefore, we assessed the reproducibility of CT numbers, an important factor on quality assurance, over short and long time periods for different substances at varying energy. CT number difference between measured and theoretical value was investigated. The scanner provided sufficient reproducibility of CT numbers for dose calculation over short and long time periods. The CT numbers of monochromatic images produced by this scanner had reasonable values for dose calculation. The CT to ED conversion curve becomes linear with respect to the relationship between CT numbers and EDs as the energy increases. We conclude that monochromatic imaging from a fast switching system can be applied for the dose calculation, keeping Hounsfield units (HU) stability. PMID:24036870

  16. Concurrent capecitabine and whole-brain radiotherapy for treatment of brain metastases in breast cancer patients.

    PubMed

    Chargari, Cyrus; Kirova, Youlia M; Diéras, Véronique; Castro Pena, Pablo; Pena, Pablo Castro; Campana, Francois; Cottu, Paul H; Pierga, JeanYves; Fourquet, Alain

    2009-07-01

    Preclinical data have demonstrated that ionizing radiation acts synergistically with capecitabine. This report retrospectively assessed the use of capecitabine concurrently with whole-brain radiotherapy (WBRT) in patients with brain metastases from breast cancer. From January 2003 to March 2005, five breast cancer patients with brain metastases were referred for WBRT with concurrent capecitabine. Median age was 44 years (range: 38-53). The median dose of capecitabine was 1,000 mg/m(2) twice daily for 14 days (day1-14). Treatment cycles were repeated every 21 days, concurrently with WBRT (30 Gy, 3 Gy per fraction, 5 days per week). Median survival after starting WBRT plus capecitabine was 6.5 months (range 1-34 months). One patient achieved a complete response. Two patients achieved partial response, including one with local control lasting until most recent follow-up. One patient had stable disease. The remaining patient was not assessable for response because of early death. Most commonly reported adverse events were nausea (n = 2) and headache (n = 2), always grade 1. Other toxicities were grade 3 hand/foot syndrome (n = 1), moderate anemia requiring transfusion and dose reduction of capecitabine (n = 1), and grade 1 mucositis (n = 1). Although promising, these preliminary data warrant further assessment of capecitabine-based chemoradiation in brain metastases from breast cancer and need to be further validated in the setting of a clinical trial. PMID:19169856

  17. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization.

    PubMed

    Garnica-Garza, H M

    2011-01-21

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 5° around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed. PMID:21160112

  18. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization

    NASA Astrophysics Data System (ADS)

    Garnica-Garza, H. M.

    2011-01-01

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 5° around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  19. Spine radiosurgery for the local treatment of spine metastases: Intensity-modulated radiotherapy, image guidance, clinical aspects and future directions

    PubMed Central

    de Moraes, Fabio Ynoe; Taunk, Neil Kanth; Laufer, Ilya; Neves-Junior, Wellington Furtado Pimenta; Hanna, Samir Abdallah; de Andrade Carvalho, Heloisa; Yamada, Yoshiya

    2016-01-01

    Many cancer patients will develop spinal metastases. Local control is important for preventing neurologic compromise and to relieve pain. Stereotactic body radiotherapy or spinal radiosurgery is a new radiation therapy technique for spinal metastasis that can deliver a high dose of radiation to a tumor while minimizing the radiation delivered to healthy, neighboring tissues. This treatment is based on intensity-modulated radiotherapy, image guidance and rigid immobilization. Spinal radiosurgery is an increasingly utilized treatment method that improves local control and pain relief after delivering ablative doses of radiation. Here, we present a review highlighting the use of spinal radiosurgery for the treatment of metastatic tumors of the spine. The data used in the review were collected from both published studies and ongoing trials. We found that spinal radiosurgery is safe and provides excellent tumor control (up to 94% local control) and pain relief (up to 96%), independent of histology. Extensive data regarding clinical outcomes are available; however, this information has primarily been generated from retrospective and nonrandomized prospective series. Currently, two randomized trials are enrolling patients to study clinical applications of fractionation schedules spinal Radiosurgery. Additionally, a phase I clinical trial is being conducted to assess the safety of concurrent stereotactic body radiotherapy and ipilimumab for spinal metastases. Clinical trials to refine clinical indications and dose fractionation are ongoing. The concomitant use of targeted agents may produce better outcomes in the future. PMID:26934240

  20. [Results of complex treatment of patients with squamous cell carcinoma of the anal canal using advanced radiotherapy technologies].

    PubMed

    Glebovskaya, V V; Tkachev, S I; Rasulov, A O; Tsaryuk, V F; Gordeev, S S; Fedyanin, M Yu; Aliev, V A; Mamedly, Z Z; Kuzmichev, D V; Trofimova, O P; Borisova, T N; Yazhgunovich, I P

    2015-01-01

    During recent decades radiotherapy is the basis, on which it is built a medical complex that is the first-line treatment of patients with squamous cell carcinoma of the anal canal. An increase of overall and disease-free survival and quality of life of patients with squamous cell carcinoma of the anal canal at the present stage of development of a comprehensive medical treatment is largely due to the improvement of technical equipment of radiotherapy departments of oncology clinics. The use of modem linear electron accelerators and systems of computer dosimetric planning to create a 3D program of isodose distribution, diagnostic devices (computed tomography and magnetic resonance imaging) as well as a number of other conditions permit accurate summarizing of proposed dose, reducing of absorbed dose to critical structures, diminishing unplanned interruptions in chemoradiotherapy course by means of modern technologies of conformal radiotherapy (3D CRT, IMRT, VMAT). The paper presents the preliminary results of a comprehensive medical treatment of 14 patients with squamous cell carcinoma of the anal canal. PMID:26571840

  1. Short-Course Accelerated Radiotherapy in Palliative Treatment of Advanced Pelvic Malignancies: A Phase I Study

    SciTech Connect

    Caravatta, Luciana; Padula, Gilbert D.A.; Macchia, Gabriella; Ferrandina, Gabriella; Bonomo, Pierluigi; Deodato, Francesco; Massaccesi, Mariangela; Mignogna, Samantha; Tambaro, Rosa; Rossi, Marco; Flocco, Mariano; Scapati, Andrea; and others

    2012-08-01

    Purpose: To define the maximum tolerated dose of a conformal short-course accelerated radiotherapy in patients with symptomatic advanced pelvic cancer. Methods and Materials: A phase I trial in 3 dose-escalation steps was designed: 14 Gy (3.5-Gy fractions), 16 Gy (4-Gy fractions), and 18 Gy (4.5-Gy fractions). The eligibility criteria included locally advanced and/or metastatic pelvic cancer and Eastern Cooperative Oncology Group performance status of {<=}3. Treatment was delivered in 2 days with twice-daily fractionation and at least an 8-hour interval. Patients were treated in cohorts of 6-12 to define the maximum tolerated dose. The dose-limiting toxicity was defined as any acute toxicity of grade 3 or greater, using the Radiation Therapy Oncology Group scale. Pain was recorded using a visual analog scale. The effect on quality of life was evaluated according to Cancer Linear Analog Scale (CLAS). Results: Of the 27 enrolled patients, 11 were male and 16 were female, with a median age of 72 years (range 47-86). The primary tumor sites were gynecologic (48%), colorectal (33.5%), and genitourinary (18.5%). The most frequent baseline symptoms were bleeding (48%) and pain (33%). Only grade 1-2 acute toxicities were recorded. No patients experienced dose-limiting toxicity. With a median follow-up time of 6 months (range 3-28), no late toxicities were observed. The overall (complete plus partial) symptom remission was 88.9% (95% confidence interval 66.0%-97.8%). Five patients (41.7%) had complete pain relief, and six (50%) showed >30% visual analog scale reduction. The overall response rate for pain was 91.67% (95% confidence interval 52.4%-99.9%). Conclusions: Conformal short course radiotherapy in twice-daily fractions for 2 consecutive days was well tolerated up to a total dose of 18 Gy. A phase II study is ongoing to confirm the efficacy on symptom control and quality of life indexes.

  2. Exploiting biological and physical determinants of radiotherapy toxicity to individualize treatment

    PubMed Central

    Scaife, J E; Barnett, G C; Noble, D J; Jena, R; Thomas, S J; West, C M L

    2015-01-01

    The recent advances in radiation delivery can improve tumour control probability (TCP) and reduce treatment-related toxicity. The use of intensity-modulated radiotherapy (IMRT) in particular can reduce normal tissue toxicity, an objective in its own right, and can allow safe dose escalation in selected cases. Ideally, IMRT should be combined with image guidance to verify the position of the target, since patients, target and organs at risk can move day to day. Daily image guidance scans can be used to identify the position of normal tissue structures and potentially to compute the daily delivered dose. Fundamentally, it is still the tolerance of the normal tissues that limits radiotherapy (RT) dose and therefore tumour control. However, the dose–response relationships for both tumour and normal tissues are relatively steep, meaning that small dose differences can translate into clinically relevant improvements. Differences exist between individuals in the severity of toxicity experienced for a given dose of RT. Some of this difference may be the result of differences between the planned dose and the accumulated dose (DA). However, some may be owing to intrinsic differences in radiosensitivity of the normal tissues between individuals. This field has been developing rapidly, with the demonstration of definite associations between genetic polymorphisms and variation in toxicity recently described. It might be possible to identify more resistant patients who would be suitable for dose escalation, as well as more sensitive patients for whom toxicity could be reduced or avoided. Daily differences in delivered dose have been investigated within the VoxTox research programme, using the rectum as an example organ at risk. In patients with prostate cancer receiving curative RT, considerable daily variation in rectal position and dose can be demonstrated, although the median position matches the planning scan well. Overall, in 10 patients, the mean difference between

  3. A cosmetic evaluation of breast cancer treatment: A randomized study of radiotherapy boost technique

    SciTech Connect

    Vass, Sylvie . E-mail: sylvie.vass@ssss.gouv.qc.ca; Bairati, Isabelle

    2005-08-01

    Purpose: To compare cosmetic results of two different radiotherapy (RT) boost techniques used in the treatment of breast cancer after whole breast radiotherapy and to identify factors affecting cosmetic outcomes. Methods and Materials: Between 1996 and 1998, 142 patients with Stage I and II breast cancer were treated with breast conservative surgery and adjuvant RT. Patients were then randomly assigned to receive a boost dose of 15 Gy delivered to the tumor bed either by iridium 192, or a combination of photons and electrons. Cosmetic evaluations were done on a 6-month basis, with a final evaluation at 36 months after RT. The evaluations were done using a panel of global and specific subjective scores, a digitized scoring system using the breast retraction assessment (BRA) measurement, and a patient's self-assessment evaluation. As cosmetic results were graded according to severity, the comparison of boost techniques was done using the ordinal logistic regression model. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) are presented. Results: At 36 months of follow-up, there was no significant difference between the two groups with respect to the global subjective cosmetic outcome (OR = 1.40; 95%CI = 0.69-2.85, p = 0.35). Good to excellent scores were observed in 65% of implant patients and 62% of photon/electron patients. At 24 months and beyond, telangiectasia was more severe in the implant group with an OR of 9.64 (95%CI = 4.05-22.92, p < 0.0001) at 36 months. The only variable associated with a worse global cosmetic outcome was the presence of concomitant chemotherapy (OR = 3.87; 95%CI = 1.74-8.62). The BRA value once adjusted for age, concomitant chemotherapy, and boost volume showed a positive association with the boost technique. The BRA value was significantly greater in the implant group (p 0.03). There was no difference in the patient's final self-assessment score between the two groups. Three variables were statistically associated with

  4. SU-E-T-379: Concave Approximations of Target Volume Dose Metrics for Intensity- Modulated Radiotherapy Treatment Planning

    SciTech Connect

    Xie, Y; Chen, Y; Wickerhauser, M; Deasy, J

    2014-06-01

    Purpose: The widely used treatment plan metric Dx (mimimum dose to the hottest x% by volume of the target volume) is simple to interpret and use, but is computationally poorly behaved (non-convex), this impedes its use in computationally efficient intensity-modulated radiotherapy (IMRT) treatment planning algorithms. We therefore searched for surrogate metrics that are concave, computationally efficient, and accurately correlated to Dx values in IMRT treatment plans. Methods: To find concave surrogates of D95—and more generally, Dx values with variable x values—we tested equations containing one or two generalized equivalent uniform dose (gEUD) functions. Fits were obtained by varying gEUD ‘a’ parameter values, as well as the linear equation coefficients. Fitting was performed using a dataset of dose-volume histograms from 498 de-identified head and neck IMRT treatment plans. Fit characteristics were tested using a crossvalidation process. Reported root-mean-square error values were averaged over the cross-validation shuffles. Results: As expected, the two-gEUD formula provided a superior fit, compared to the single-gEUD formula. The best approximation uses two gEUD terms: 16.25 x gEUD[a=0.45] – 15.30 x gEUD[a=1.75] – 0.69. The average root-mean-square error on repeated (70/30) cross validation was 0.94 Gy. In addition, a formula was found that reasonably approximates Dx for x between 80% and 96%. Conclusion: A simple concave function using two gEUD terms was found that correlates well with PTV D95s for these head and neck treatment plans. More generally, a formula was found that represents well the Dx for x values from 80% to 96%, thus providing a computationally efficient formula for use in treatment planning optimization. The formula may need to be adjusted for other institutions with different treatment planning protocols. We conclude that the strategy of replacing Dx values with gEUD-based formulas is promising.

  5. Dosimetric study of 2D ion chamber array matrix for the modern radiotherapy treatment verification.

    PubMed

    Saminathan, Sathiyan; Manickam, Ravikumar; Chandraraj, Varatharaj; Supe, Sanjay S

    2010-01-01

    Intensity-modulated radiotherapy treatment demands stringent quality assurance and accurate dose determination for delivery of highly conformal dose to the patients. Generally 3D dose distributions obtained from a treatment planning system have to be verified by dosimetric methods. Mainly, a comparison of two-dimensional calculated and measured data in several coplanar planes is performed. In principle, there are many possibilities to measure two-dimensional dose distributions such as films, flat-panel electronic portal imaging devices (EPID), ion chambers and ionization chamber arrays, and radiographic and radiochromic films. The flat-panel EPIDs show a good resolution and offer a possibility for real-time measurements: however to convert the signal into dose, a separate commercial algorithm is required. The 2D ion chamber array system offers the real-time measurements. In this study, dosimetric characteristics of 2D ion chamber array matrix were analyzed for verification of radiotherapy treatments. The dose linearity and dose rate effect of the I'matriXX device was studied using 6 MV, 18 MV photons and 12 MeV electrons. The output factor was estimated using I'matriXX device and compared with ion chamber measurements. The ion chamber array system was found to be linear in the dose range of 2-500 cGy and the response of the detector was found to be independent of dose rate between 100 MU/min to 600 MU/min. The estimated relative output factor with I'matriXX was found to match very well with the ion chamber measurements. To check the final dose delivered during IMRT planning, dose distribution patterns such as field-in-field, pyramidal, and chair tests were generated with the treatment planning system (TPS) and the same was executed in the accelerator and measured with the I'matriXX device. The dose distribution pattern measured by the matrix device for field-in-field, pyramidal, and chair test were found to be in good agreement with the calculated dose distribution

  6. [Importance of local skin treatments during radiotherapy for prevention and treatment of radio-induced epithelitis].

    PubMed

    Chargari, C; Fromantin, I; Kirova, Y M

    2009-07-01

    Radio-epithelitis represents a common problem, for which treatments are characterized by a great heterogeneity. The present review of literature focuses on data referenced in Pubmed((c))/Medline((c)) and published in French/English. Despite a real preclinical rationale, aloe vera and trolamine failed to demonstrate any benefit in the prophylactic settings. In a prospective assessment phase III assessment, Calendula Officinalis was shown to be superior to trolamine for the prevention of radio-epithelitis. In the curative settings, sucrafalte failed to demonstrate any benefit. The benefit of dermocorticoids was suggested in terms of erythema and itching. Promising clinical results are available with hyaluronic acid (MA S065D and Ialugen) and silver leaf may reduce the intensity of cutaneous radio-induced side effects. Data from the literature are conflicting, making real the difficulty to adopt from clinical trials any proof-of-principle strategy. Considering these uncertainties, several strategies are allowed. New topics are under investigation. Present data from the literature highlight the need for further trials, in order to propose evidence-based treatments and to harmonize clinical practice. PMID:19524470

  7. [{sup 18}FDG] PET-CT-Based Intensity-Modulated Radiotherapy Treatment Planning of Head and Neck Cancer

    SciTech Connect

    El-Bassiouni, Mazen; Ciernik, I. Frank Davis, J. Bernard; El-Attar, Inas; Reiner, Beatrice; Burger, Cyrill; Goerres, Gerhard W.; Studer, Gabriela M.

    2007-09-01

    Purpose: To define the best threshold for tumor volume delineation of the (18) fluoro-2-deoxy-glucose positron emission tomography ({sup 18}FDG-PET) signal for radiotherapy treatment planning of intensity-modulated radiotherapy (IMRT) in head and neck cancer. Methods and Materials: In 25 patients with head-and-neck cancer, CT-based gross tumor volume (GTV{sub CT}) was delineated. After PET-CT image fusion, window level (L) was adapted to best fit the GTV{sub CT}, and GTV{sub PET} was delineated. Tumor maximum (S) and background uptake (B) were measured, and the threshold of the background-subtracted tumor maximum uptake (THR) was used for PET signal segmentation. Gross tumor volumes were expanded to planning target volumes (PTVs) and analyzed. Results: The mean value of S was 40 kBq/mL, S/B ratio was 16, and THR was 26%. The THR correlated with S (r = -0.752), but no correlation between THR and the S/B ratio was seen (r = -0.382). In 77% of cases, S was >30 kBq/mL, and in 23% it was {<=}30 kBq/mL, with a mean THR of 21.4% and 41.6%, respectively (p < 0.001). Using PTV{sub PET} in radiotherapy treatment planning resulted in a reduced PTV in 72% of cases, while covering 88.2% of GTV{sub CT}, comparable to the percentage of GTV{sub PET} covered by PTV{sub CT} (p = 0.15). Conclusions: A case-specific PET signal threshold is optimal in PET-based radiotherapy treatment planning. Signal gating using a THR of 20% in tumors with S >30% {+-} 1.6% kBq/mL and 40% in tumors with S {<=}30% {+-} 1.6% kBq/mL is suitable.

  8. Effectiveness of Carbon Ion Radiotherapy in the Treatment of Skull-Base Chordomas

    SciTech Connect

    Schulz-Ertner, Daniela . E-mail: Daniela.Ertner@med.uni-heidelberg.de; Karger, Christian P.; Feuerhake, Alexandra; Nikoghosyan, Anna; Combs, Stephanie E.; Jaekel, Oliver; Edler, Lutz; Scholz, Michael; Debus, Juergen

    2007-06-01

    Purpose: The aim of this study was to evaluate the effectiveness and toxicity of carbon ion radiotherapy in chordomas of the skull base. Methods and Materials: Between November 1998 and July 2005, a total of 96 patients with chordomas of the skull base have been treated with carbon ion radiation therapy (RT) using the raster scan technique at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt, Germany. All patients had gross residual tumors. Median total dose was 60 CGE (range, 60-70 CGE) delivered in 20 fractions within 3 weeks. 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 the Radiation Therapy Oncology Group (RTOG) / European Organization for Research and Treatment of Cancer (EORTC) score. Results: Mean follow-up was 31 months (range, 3-91 months). Fifteen patients developed local recurrences after carbon ion RT. The actuarial local control rates were 80.6% and 70.0% at 3 and 5 years, respectively. Target doses in excess of 60 CGE and primary tumor status were associated with higher local control rates. Overall survival was 91.8% and 88.5% at 3 and 5 years, respectively. Late toxicity consisted of optic nerve neuropathy RTOG/EORTC Grade 3 in 4.1% of the patients and necrosis of a fat plomb in 1 patient. Minor temporal lobe injury (RTOG/EORTC Grade 1-2) occurred in 7 patients (7.2%). Conclusions: Carbon ion RT offers an effective treatment option for skull-base chordomas with acceptable toxicity. Doses in excess of 75 CGE with 2 CGE per fraction are likely to increase local control probability.

  9. sup 211 At-methylene blue for targeted radiotherapy of human melanoma xenografts: Treatment of micrometastases

    SciTech Connect

    Link, E.M.; Carpenter, R.N. )

    1990-05-15

    Treatment of micrometastases of HX34 human melanoma grown as xenografts in nude mice represents an advanced stage of preclinical investigations concerning targeted radiotherapy of this neoplasm using 3,7-(dimethylamino)phenazathionium chloride methylene blue (MTB) labeled with astatine-211 (211At) (alpha-particle emitter). The therapeutic effectiveness of 211At-MTB administered i.v. was determined by a lung colony assay combined with a search for metastases to organs other than the lungs. A single dose of 211At-MTB lowered the HX34 cell surviving fraction in lungs to below 10% almost independently of the time interval between cell inoculation and radioisotope injection and of 211At-MTB radioactivity within its investigated range. Radiation dose and the time of its administration did, however, influence the size of lung colonies. In contrast, the efficacy of 211At-MTB treatment as assessed by both surviving fraction and colony size was significantly dependent on a number of HX34 cells inoculated initially into mice. These results are explained by a short range of alpha-particles emitted by 211At and a mechanism of growth of lung colonies from tumor cells circulating with blood and blocking lung capillaries. Metastases in organs other than lungs and characteristic of control animals were not found in mice treated with 211At-MTB. The high therapeutic efficacy achieved proved that 211At-MTB is a very efficient scavenger of single melanoma cells distributed through blood and micrometastases with sizes below the limit of clinical detection.

  10. 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. PMID:26509449

  11. 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

  12. Case report of a near medical event in stereotactic radiotherapy due to improper units of measure from a treatment planning system

    SciTech Connect

    Gladstone, D. J.; Li, S.; Jarvis, L. A.; Hartford, A. C.

    2011-07-15

    Purpose: The authors hereby notify the Radiation Oncology community of a potentially lethal error due to improper implementation of linear units of measure in a treatment planning system. The authors report an incident in which a patient was nearly mistreated during a stereotactic radiotherapy procedure due to inappropriate reporting of stereotactic coordinates by the radiation therapy treatment planning system in units of centimeter rather than in millimeter. The authors suggest a method to detect such errors during treatment planning so they are caught and corrected prior to the patient positioning for treatment on the treatment machine. Methods: Using pretreatment imaging, the authors found that stereotactic coordinates are reported with improper linear units by a treatment planning system. The authors have implemented a redundant, independent method of stereotactic coordinate calculation. Results: Implementation of a double check of stereotactic coordinates via redundant, independent calculation is simple and accurate. Use of this technique will avoid any future error in stereotactic treatment coordinates due to improper linear units, transcription, or other similar errors. Conclusions: The authors recommend an independent double check of stereotactic treatment coordinates during the treatment planning process in order to avoid potential mistreatment of patients.

  13. Radiotherapy in Ewing tumors of the vertebrae: Treatment results and local relapse analysis of the Chess 81/86 and EICESS 92 trials

    SciTech Connect

    Schuck, Andreas . E-mail: schuck@uni-muenster.de; Ahrens, Susanne; Schorlemer, Ines von; Kuhlen, Michaela; Paulussen, Michael; Hunold, Andrea; Gosheger, Georg; Winkelmann, Winfried; Dunst, Juergen; Willich, Normann; Juergens, Heribert

    2005-12-01

    Purpose: Treatment results in patients with Ewing tumors of the vertebrae enrolled in the Cooperative Ewing's Sarcoma Study (CESS) 81, 86, and the European Intergroup Cooperative Ewing's Sarcoma Study (EICESS) 92 trials were analyzed with special emphasis on radiation-associated factors. Patients and Methods: A retrospective analysis was performed on 116 patients with primary tumors of the cervical, thoracic, or lumbar vertebrae treated between 1981 and 1999. Furthermore, a relapse analysis was done on those patients who underwent radiotherapy and subsequently had a local recurrence. Results: A total of 64.6% of the patients received definitive radiotherapy; 27.5% of patients had surgery and radiotherapy. Only 4 patients (3.4%) underwent definitive surgery. Twenty-seven patients presented with metastases at diagnosis. 22.4% of the total group developed a local relapse. Among the subgroup with definitive radiotherapy, local recurrence was seen in 17 of 75 patients (22.6%). Event-free survival and survival at 5 years were 47% and 58%, respectively. Of the 14 evaluable patients with a local relapse after radiotherapy, 13 were in-field. No correlation between radiation dose and local control could be found. Conclusion: Surgery with wide resection margins is rarely possible. The results after definitive radiotherapy in vertebral tumors are comparable to those of other tumor sites when definitive radiotherapy is given. Nearly all local relapses after radiotherapy are in-field.

  14. Industrial waste treatment process engineering. Volume 2: Biological processes

    SciTech Connect

    Celenza, G.J.

    1999-11-01

    Industrial Waste Treatment Process Engineering is a step-by-step implementation manual in three volumes, detailing the selection and design of industrial liquid and solid waste treatment systems. It consolidates all the process engineering principles required to evaluate a wide range of industrial facilities, starting with pollution prevention and source control and ending with end-of-pipe treatment technologies. This three-volume set is a practical guide for environmental engineers with process implementation responsibilities; a one-stop resource for process engineering requirements--from plant planning to implementing specific treatment technologies for unit operations; a comprehensive reference for industrial waste treatment technologies; and includes calculations and worked problems based on industry cases. The contents of Volume 2 include: aeration; aerobic biological oxidation; activated sludge system; biological oxidation: lagoons; biological oxidation: fixed film processes; aerobic digesters; anaerobic waste treatment, anaerobic sludge treatment; and sedimentation.

  15. SITE TECHNOLOGY CAPSULE: ZENOGEM™ WASTEWATER TREATMENT PROCESS

    EPA Science Inventory

    Zenon Environmental System's ZenoGem™ Wastewater Treatment Process treats aqueous media contaminated with volatile/semi-volatile organic compounds. This technology combines aerobic biological treatment to remove biodegradable organic compounds with ultrafiltration to separate res...

  16. Radiotherapy Treatment Plans With RapidArc for Prostate Cancer Involving Seminal Vesicles and Lymph Nodes

    SciTech Connect

    Yoo, Sua; Wu, Q. Jackie; Lee, W. Robert; Yin Fangfang

    2010-03-01

    Purpose: Dosimetric results and treatment delivery efficiency of RapidArc plans to those of conventional intensity-modulated radiotherapy (IMRT) plans were compared using the Eclipse treatment planning system for high-risk prostate cancer. Materials and Methods: This study included 10 patients. The primary planning target volume (PTV{sub P}) contained prostate, seminal vesicles, and pelvic lymph nodes with a margin. The boost PTV (PTV{sub B}) contained prostate and seminal vesicles with a margin. The total prescription dose was 75.6 Gy (46.8 Gy to PTV{sub P} and an additional 28.8 Gy to PTV{sub B}; 1.8 Gy/fraction). Three plans were generated for each PTV: Multiple-field IMRT, one-arc RapidArc (1ARC), and two-arc RapidArc (2ARC). Results: In the primary IMRT with PTV{sub P}, average mean doses to bladder, rectum and small bowel were lower by 5.9%, 7.7% and 4.3%, respectively, than in the primary 1ARC and by 3.6%, 4.8% and 3.1%, respectively, than in the primary 2ARC. In the boost IMRT with PTV{sub B}, average mean doses to bladder and rectum were lower by 2.6% and 4.8% than with the boost 1ARC and were higher by 0.6% and 0.2% than with the boost 2ARC. Integral doses were 7% to 9% higher with RapidArc than with IMRT for both primary and boost plans. Treatment delivery time was reduced by 2-7 minutes using RapidArc. Conclusion: For PTVs including prostate, seminal vesicles, and lymph nodes, IMRT performed better in dose sparing for bladder, rectum, and small bowel than did RapidArc. For PTVs including prostate and seminal vesicles, RapidArc with two arcs provided plans comparable to those for IMRT. The treatment delivery is more efficient with RapidArc.

  17. Fiducial registration error as a statistical process control metric in image-guidance radiotherapy with fiducial markers.

    PubMed

    Ung, N M; Wee, L

    2011-12-01

    Portal imaging of implanted fiducial markers has been in use for image-guided radiotherapy (IGRT) of prostate cancer, with ample attention to localization accuracy and organ motion. The geometric uncertainties in point-based rigid-body matching algorithms during localization of prostate fiducial markers can be quantified in terms of a fiducial registration error (FRE). In this study, the aim is to demonstrate how statistical process control (SPC) can be used to intercept potential problems with rigid-body matching algorithms in a retrospective study of FRE for a pilot cohort of 34 patients with fiducial markers. A procedure for estimating control parameters of a SPC control chart (x-chart) from a small number of initial observations (N) of FRE was implemented. The sensitivity analysis of N on the number of 'in-control' and 'out-of-control' x-charts was also performed. Uncorrected rotational offsets of an individual patient were examined to elucidate possible correlations with the behaviours of an x-chart. Four specific types of qualitative x-chart behaviour have been observed. The number of out-of-control processes was insensitive to the choice of N, provided N ≥ 5. Residual errors of rigid-body registration were contributed from uncorrected rotational offsets in 5 out of 15 'out-of-control' x-charts. Out-of-control x-charts were also shown to be correlated with potential changes in the IGRT processes, which may compromise the quality of the radiation treatment delivery. The SPC methodology, implemented in the form of individually customized x-charts, has been shown to be a useful tool for monitoring process reliability during fiducial-based IGRT for prostate cancer. PMID:22080792

  18. Fiducial registration error as a statistical process control metric in image-guidance radiotherapy with fiducial markers

    NASA Astrophysics Data System (ADS)

    Ung, N. M.; Wee, L.

    2011-12-01

    Portal imaging of implanted fiducial markers has been in use for image-guided radiotherapy (IGRT) of prostate cancer, with ample attention to localization accuracy and organ motion. The geometric uncertainties in point-based rigid-body matching algorithms during localization of prostate fiducial markers can be quantified in terms of a fiducial registration error (FRE). In this study, the aim is to demonstrate how statistical process control (SPC) can be used to intercept potential problems with rigid-body matching algorithms in a retrospective study of FRE for a pilot cohort of 34 patients with fiducial markers. A procedure for estimating control parameters of a SPC control chart (x-chart) from a small number of initial observations (N) of FRE was implemented. The sensitivity analysis of N on the number of 'in-control' and 'out-of-control' x-charts was also performed. Uncorrected rotational offsets of an individual patient were examined to elucidate possible correlations with the behaviours of an x-chart. Four specific types of qualitative x-chart behaviour have been observed. The number of out-of-control processes was insensitive to the choice of N, provided N >= 5. Residual errors of rigid-body registration were contributed from uncorrected rotational offsets in 5 out of 15 'out-of-control' x-charts. Out-of-control x-charts were also shown to be correlated with potential changes in the IGRT processes, which may compromise the quality of the radiation treatment delivery. The SPC methodology, implemented in the form of individually customized x-charts, has been shown to be a useful tool for monitoring process reliability during fiducial-based IGRT for prostate cancer.

  19. Assessment of contralateral mammary gland dose in the treatment of breast cancer using accelerated hypofractionated radiotherapy

    PubMed Central

    Tolia, Maria; Platoni, Kalliopi; Foteineas, Andreas; Kalogeridi, Maria-Aggeliki; Zygogianni, Anna; Tsoukalas, Nikolaos; Caimi, Mariangela; Margari, Niki; Dilvoi, Maria; Pantelakos, Panagiotis; Kouvaris, John; Kouloulias, Vassilis

    2011-01-01

    AIM: To measure the dose distribution, related to the treatment planning calculations, in the contralateral mammary gland of breast cancer patients treated with accelerated hypofractionated 3-dimensional conformal radiotherapy. METHODS: Thirty-four prospectively selected female patients with right breast cancer (pN0, negative surgical margins) were treated with breast-conserving surgery. A total dose of 42.5 Gy (2.66 Gy/fraction) was prescribed; it was requested that planning target volumes be covered by the 95% isodose line. The contralateral mammary gland was defined on CT simulation. The dose received was evaluated by dose volume histograms. RESULTS: The measured contralateral breast doses were: (1) Dose maximum: 290-448 cGy [Equivalent (Eq) 337-522 cGy]; (2) Mean dose: 45-70 cGy (Eq 524-815 cGy); and (3) Median dose: 29-47 cGy (337-547 cGy) for total primary breast dose of 42.5 Gy in 16 equal fractions. The spearman rho correlation showed statistical significance between the contralateral breast volume and maximum dose (P = 0.0292), as well as mean dose (P = 0.0025) and median dose (P = 0.046) to the breast. CONCLUSION: Minimizing the dose to the contralateral breast has to be one of the priorities of the radiation oncologist when using short schedules because of the radiosensitivity of this organ at risk. Further study is necessary to assess the long-term clinical impact of this schedule. PMID:22013502

  20. Biochemical Imaging of Gliomas Using MR Spectroscopic Imaging for Radiotherapy Treatment Planning

    NASA Astrophysics Data System (ADS)

    Heikal, Amr Ahmed

    This thesis discusses the main obstacles facing wide clinical implementation of magnetic resonance spectroscopic imaging (MRSI) as a tumor delineation tool for radiotherapy treatment planning, particularly for gliomas. These main obstacles are identified as 1. observer bias and poor interpretational reproducibility of the results of MRSI scans, and 2. the long scan times required to conduct MRSI scans. An examination of an existing user-independent MRSI tumor delineation technique known as the choline-to-NAA index (CNI) is conducted to assess its utility in providing a tool for reproducible interpretation of MRSI results. While working with spatial resolutions typically twice those on which the CNI model was originally designed, a region of statistical uncertainty was discovered between the tumor and normal tissue populations and as such a modification to the CNI model was introduced to clearly identify that region. To address the issue of long scan times, a series of studies were conducted to adapt a scan acceleration technique, compressed sensing (CS), to work with MRSI and to quantify the effects of such a novel technique on the modulation transfer function (MTF), an important quantitative imaging metric. The studies included the development of the first phantom based method of measuring the MTF for MRSI data, a study of the correlation between the k-space sampling patterns used for compressed sensing and the resulting MTFs, and the introduction of a technique circumventing some of side-effects of compressed sensing by exploiting the conjugate symmetry property of k-space. The work in this thesis provides two essential steps towards wide clinical implementation of MRSI-based tumor delineation. The proposed modifications to the CNI method coupled with the application of CS to MRSI address the two main obstacles outlined. However, there continues to be room for improvement and questions that need to be answered by future research.

  1. Combined treatment of anaplastic thyroid carcinoma with surgery, chemotherapy, and hyperfractionated accelerated external radiotherapy

    SciTech Connect

    De Crevoisier, Renaud . E-mail: rdecrevo@mdanderson.org; Baudin, Eric; Bachelot, Anne; Leboulleux, Sophie; Travagli, Jean-Paul; Caillou, Bernard; Schlumberger, Martin

    2004-11-15

    Purpose: To analyze a prospective protocol combining surgery, chemotherapy (CT), and hyperfractionated accelerated radiotherapy (RT) in anaplastic thyroid carcinoma. Methods and materials: Thirty anaplastic thyroid carcinoma patients (mean age, 59 years) were treated during 1990-2000. Tumor extended beyond the capsule gland in 26 patients, with tracheal extension in 8. Lymph node metastases were present in 18 patients and lung metastases in 6. Surgery was performed before RT-CT in 20 patients and afterwards in 4. Two cycles of doxorubicin (60 mg/m{sup 2}) and cisplatin (120 mg/m{sup 2}) were delivered before RT and four cycles after RT. RT consisted of two daily fractions of 1.25 Gy, 5 days per week to a total dose of 40 Gy to the cervical lymph node areas and the superior mediastinum. Results: Acute toxicity (World Health Organization criteria) was Grade 3 or 4 pharyngoesophagitis in 10 patients; Grade 4 neutropenia in 21, with infection in 13; and Grade 3 or 4 anemia and thrombopenia in 8 and 4, respectively. At the end of the treatment, a complete local response was observed in 19 patients. With a median follow-up of 45 months (range, 12-78 months), 7 patients were alive in complete remission, of whom 6 had initially received a complete tumor resection. Overall survival rate at 3 years was 27% (95% confidence interval 10-44%) and median survival 10 months. In multivariate analysis, tracheal extension and macroscopic complete tumor resection were significant factors in overall survival. Death was related to local progression in 5% of patients, to distant metastases in 68%, and to both in 27%. Conclusions: Main toxicity was hematologic. High long-term survival was obtained when RT-CT was given after complete surgery. This protocol avoided local tumor progression, and death was mainly caused by distant metastases.

  2. Percutaneous biliary stenting combined with radiotherapy as a treatment for unresectable hilar cholangiocarcinoma

    PubMed Central

    TAN, YONG; ZHU, JIAN-YONG; QIU, BAO-AN; XIA, NIAN-XIN; WANG, JING-HAN

    2015-01-01

    Hilar cholangiocarcinoma is often unresectable at the time of the initial diagnosis, and the provision of a definite palliative benefit is important in patients with unresectable hilar cholangiocarcinoma. The aim of the present study was to evaluate the safety of percutaneous biliary stenting and to analyze whether percutaneous biliary stenting combined with radiotherapy (RT) prolonged the stent patency and survival time of patients. In total, the cases of 38 patients with unresectable hilar cholangiocarcinoma that underwent percutaneous biliary stenting at the Navy General Hospital were retrospectively reviewed in the present study. Uncovered metallic stenting (UMS) combined with RT was administered to 25 patients, and UMS alone was administered to 13 patients. The records of early complications subsequent to percutaneous biliary stenting were collected, and the stent patency and survival times of patients were analyzed and compared between the two groups. The technical success rate of the procedure was 100% and the successful drainage rate was 86.8%. The overall early complication rate was 15.8% and the procedure-associated mortality rate was 2.6%. The median stent patency was 326 days in the UMS+RT group and 196 days in the UMS group (P=0.022). The UMS+RT group (median, 367 days) demonstrated a longer survival time compared with the UMS group (median, 267 days; P=0.025). Percutaneous biliary stenting offers a safe and effective method for the palliative treatment of patients with unresectable hilar cholangiocarcinoma, and percutaneous biliary stenting combined with RT may prolong stent patency and patient survival time. PMID:26622885

  3. Concurrent Androgen Deprivation Therapy During Salvage Prostate Radiotherapy Improves Treatment Outcomes in High-Risk Patients

    SciTech Connect

    Soto, Daniel E.; Passarelli, Michael N.; Daignault, Stephanie; Sandler, Howard M.

    2012-03-01

    Purpose: To determine whether concurrent androgen deprivation therapy (ADT) during salvage radiotherapy (RT) improves prostate cancer treatment outcomes. Methods and Materials: A total of 630 postprostatectomy patients were retrospectively identified who were treated with three-dimensional conformal RT. Of these, 441 were found to be treated for salvage indications. Biochemical failure was defined as prostate-specific antigen (PSA) of 0.2 ng/mL or greater above nadir with another PSA increase or the initiation of salvage ADT. Progression-free survival (PFS) was defined as the absence of biochemical failure, continued PSA rise despite salvage therapy, initiation of systemic therapy, clinical progression, or distant failure. Multivariate-adjusted Cox proportional hazards modeling was performed to determine which factors predict PFS. Results: Low-, intermediate-, and high-risk patients made up 10%, 24%, and 66% of patients, respectively. The mean RT dose was 68 Gy. Twenty-four percent of patients received concurrent ADT (cADT). Regional pelvic nodes were treated in 16% of patients. With a median follow-up of 3 years, the 3-year PFS was 4.0 years for cADT vs. 3.4 years for cADT patients (p = 0.22). Multivariate analysis showed that concurrent ADT (p = 0.05), Gleason score (p < 0.001), and pre-RT PSA (p = 0.03) were independent predictors of PFS. When patients were stratified by risk group, the benefits of cADT (hazard ratio, 0.65; p = 0.046) were significant only for high-risk patients. Conclusions: This retrospective study showed a PFS benefit of concurrent ADT during salvage prostate RT. This benefit was observed only in high-risk patients.

  4. Pulmonary Changes After Radiotherapy for Conservative Treatment of Breast Cancer: A Prospective Study

    SciTech Connect

    Krengli, Marco Sacco, Mariano; Loi, Gianfranco; Masini, Laura; Ferrante, Daniela; Gambaro, Giuseppina; Ronco, Marco; Magnani, Corrado; Carriero, Alessandro

    2008-04-01

    Purpose: Radiotherapy (RT) after conservative surgery for breast cancer involves part of the pulmonary parenchyma with a potential detrimental effect of reducing the normal functional reserve. Such an effect deserves to be studied in depth, considering the given long life expectancy of these women. We prospectively analyzed high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) with correlation with dosimetric data from RT. Methods and Materials: Lung HRCT and PFTs were performed in 41 women who had undergone conservative surgery for breast cancer before and 3 and 9 months after postoperative RT. The PFTs included forced vital capacity, forced expiratory volume in 1 s, total lung capacity, maximal expiratory flow at 50% and 25% of vital capacity, and the diffusion capacity of carbon monoxide. HRCT was matched with the RT treatment plan images to analyze the dosimetric correlation. Results: At 3 months after RT, the lung alterations were classified at HRCT as follows: 46.3% were Grade 1, 24.4% Grade 2, and 7.3% Grade 3, and at 9 months, 58.5% were Grade 1, 19.5% Grade 2, and 0% Grade 3. The PFTs showed a significant decrease at 3 months, with only partial recovery at 9 months. Chemotherapy, but not hormonal therapy, was associated with PFT changes. The grade of fibrosis increased with increasing lung volume treated to a dose {>=}25 Gy. Conclusion: Lung changes, mainly related to damage to the alveolar-capillary barrier and smallest airway ramifications, were observed at 3 months, with only partial recovery at 9 months after RT. Minimizing the lung volume receiving {>=}25 Gy could reduce pulmonary toxicity.

  5. The Role of Radiotherapy and Chemotherapy in the Treatment of Primary Adult High Grade Gliomas: Assessment of Patients for These Treatment Approaches and the Common Immediate Side Effects

    PubMed Central

    Philip-Ephraim, E. E.; Eyong, K. I.; Williams, U. E.; Ephraim, R. P.

    2012-01-01

    Gliomas are the commonest primary brain tumours in adults. They are usually classified and graded according to the criteria by the World Health Organisation. High-grade gliomas are the most malignant primary brain tumours. Conventional therapies include surgery, radiotherapy, and chemotherapy. The tumours often demonstrate high levels of resistance to these conventional therapies, and in spite of treatment advances the prognosis remains poor. PMID:23304556

  6. X-ray volumetric imaging in image-guided radiotherapy: The new standard in on-treatment imaging

    SciTech Connect

    McBain, Catherine A.; Henry, Ann M. . E-mail: catherine.mcbain@christie-tr.nwest.nhs.uk; Sykes, Jonathan; Amer, Ali; Marchant, Tom; Moore, Christopher M.; Davies, Julie; Stratford, Julia; McCarthy, Claire; Porritt, Bridget; Williams, Peter; Khoo, Vincent S.; Price, Pat

    2006-02-01

    Purpose: X-ray volumetric imaging (XVI) for the first time allows for the on-treatment acquisition of three-dimensional (3D) kV cone beam computed tomography (CT) images. Clinical imaging using the Synergy System (Elekta, Crawley, UK) commenced in July 2003. This study evaluated image quality and dose delivered and assessed clinical utility for treatment verification at a range of anatomic sites. Methods and Materials: Single XVIs were acquired from 30 patients undergoing radiotherapy for tumors at 10 different anatomic sites. Patients were imaged in their setup position. Radiation doses received were measured using TLDs on the skin surface. The utility of XVI in verifying target volume coverage was qualitatively assessed by experienced clinicians. Results: X-ray volumetric imaging acquisition was completed in the treatment position at all anatomic sites. At sites where a full gantry rotation was not possible, XVIs were reconstructed from projection images acquired from partial rotations. Soft-tissue definition of organ boundaries allowed direct assessment of 3D target volume coverage at all sites. Individual image quality depended on both imaging parameters and patient characteristics. Radiation dose ranged from 0.003 Gy in the head to 0.03 Gy in the pelvis. Conclusions: On-treatment XVI provided 3D verification images with soft-tissue definition at all anatomic sites at acceptably low radiation doses. This technology sets a new standard in treatment verification and will facilitate novel adaptive radiotherapy techniques.

  7. The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations

    SciTech Connect

    D.L. Henderson; S. Yoo; M. Kowalok; T.R. Mackie; B.R. Thomadsen

    2001-10-30

    The goal of this project is to investigate the use of the adjoint method, commonly used in the reactor physics community, for the optimization of radiation therapy patient treatment plans. Two different types of radiation therapy are being examined, interstitial brachytherapy and radiotherapy. In brachytherapy radioactive sources are surgically implanted within the diseased organ such as the prostate to treat the cancerous tissue. With radiotherapy, the x-ray source is usually located at a distance of about 1-metere from the patient and focused on the treatment area. For brachytherapy the optimization phase of the treatment plan consists of determining the optimal placement of the radioactive sources, which delivers the prescribed dose to the disease tissue while simultaneously sparing (reducing) the dose to sensitive tissue and organs. For external beam radiation therapy the optimization phase of the treatment plan consists of determining the optimal direction and intensity of beam, which provides complete coverage of the tumor region with the prescribed dose while simultaneously avoiding sensitive tissue areas. For both therapy methods, the optimal treatment plan is one in which the diseased tissue has been treated with the prescribed dose and dose to the sensitive tissue and organs has been kept to a minimum.

  8. [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

  9. A prospective longitudinal study of voice characteristics and health-related quality of life outcomes following laryngeal cancer treatment with radiotherapy.

    PubMed

    Karlsson, Therese; Bergström, Liza; Ward, Elizabeth; Finizia, Caterina

    2016-06-01

    Background To investigate potential changes in perceptual, acoustic and patient-reported outcomes over 12 months for laryngeal cancer patients treated with radiotherapy. Material and methods A total of 40 patients with Tis-T3 laryngeal cancer treated with curative intent by radiotherapy were included in this prospective longitudinal descriptive study. Patients were followed pre-radiotherapy, one month, six months and 12 months post-radiotherapy, where voice recordings and patient-reported outcome instruments (European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire Core30, Head and Neck35, Swedish Self-Evaluation of Communication Experiences after Laryngeal Cancer) were completed at each appointment. Perceptual analysis, using the Grade-Roughness-Breathiness-Asthenia-Strain scale and vocal fry parameters, and acoustic measures including harmonics-to-noise ratio (HNR), jitter, shimmer and mean spoken fundamental frequency (MSFF) were produced from voice recordings. Results All patients presented with dysphonic voices pre-radiotherapy, where 95% demonstrated some degree of vocal roughness. This variable improved significantly immediately post-radiotherapy, however, then deteriorated again between six and 12 months. Vocal fry also increased significantly at 12 months. Acoustic measures were abnormal pre- and post-treatment with no significant change noted except for MSFF, which lowered significantly by 12 months. Health-related quality of life (HRQL) deteriorated post-radiotherapy but returned to pretreatment levels by 12 months. Conclusion By 12 months, most perceptual, acoustic, patient-reported voice and HRQL outcomes for laryngeal cancer patients treated by radiotherapy had showed no significant improvements compared to pretreatment function. Further studies are required to investigate potential benefits of voice rehabilitation following radiotherapy. PMID:27056401

  10. Energy Dependence of Measured CT Numbers on Substituted Materials Used for CT Number Calibration of Radiotherapy Treatment Planning Systems

    PubMed Central

    Mahmoudi, Reza; Jabbari, Nasrollah; aghdasi, Mehdi; Khalkhali, Hamid Reza

    2016-01-01

    Introduction For accurate dose calculations, it is necessary to provide a correct relationship between the CT numbers and electron density in radiotherapy treatment planning systems (TPSs). The purpose of this study was to investigate the energy dependence of measured CT numbers on substituted materials used for CT number calibration of radiotherapy TPSs and the resulting errors in the treatment planning calculation doses. Materials and Methods In this study, we designed a cylindrical water phantom with different materials used as tissue equivalent materials for the simulation of tissues and obtaining the related CT numbers. For evaluating the effect of CT number variations of substituted materials due to energy changing of scanner (kVp) on the dose calculation of TPS, the slices of the scanned phantom at three kVp's were imported into the desired TPSs (MIRS and CorePLAN). Dose calculations were performed on two TPSs. Results The mean absolute percentage differences between the CT numbers of CT scanner and two treatment planning systems for all the samples were 3.22%±2.57% for CorePLAN and 2.88%±2.11% for MIRS. It was also found that the maximum absolute percentage difference between all of the calculated doses from each photon beam of linac (6 and 15 MV) at three kVp's was less than 1.2%. Discussion The present study revealed that, for the materials with effective low atomic number, the mean CT number increased with increasing energy, which was opposite for the materials with an effective high atomic number. We concluded that the tissue substitute materials had a different behavior in the energy ranges from 80 to 130 kVp. So, it is necessary to consider the energy dependence of the substitute materials used for the measurement or calibration of CT number for radiotherapy treatment planning systems. PMID:27391672

  11. Sci—Thur PM: Planning and Delivery — 02: Treatment planning workflow for very high-energy electron beam radiotherapy

    SciTech Connect

    Bazalova, Magdalena; Qu, Bradley; Palma, Bianey; Maxim, Peter; Loo, Billy; Hårdemark, Bjorn; Hynning, Elin

    2014-08-15

    Purpose: To develop treatment planning workflow for rapid radiotherapy delivered with very-high energy electron (VHEE) scanning beam. Methods: VHEE radiotherapy treatment planning was performed by linking Monte Carlo (MC) dose calculations with inverse optimization in a research version of RayStation. In order to study a number of treatment parameters, a Matlab graphical user interface (GUI) for calculation of VHEE beamlet dose was developed. Through the GUI, EGSnrc MC simulations were run for a number of beam energies, number of beams, beamlet spot and grid sizes, and machine bore sizes. VHEE plans for a pediatric patient with a 4.3 cm{sup 3} brain target optimized with spot-scanning algorithm in RayStation were compared to the clinically delivered 6 MV VMAT plan. Results and Discussion: VHEE beam energy had the largest effect on the quality of dose distributions. For the same target dose, the mean doses to critical organs decreased by 10–15% when planned with 100 MeV compared to 60 MeV. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams. While beamlet spacing and bore size had a small effect on VHEE dose distributions, 0.1-3mm beamlet sizes resulted in identical dose distributions. Critical organ doses were by up to 70% lower in the best VHEE plan compared to the clinical 6 MV VMAT plan. Conclusions: We have developed a GUI for MC beamlet generation for treatment planning of VHEE radiotherapy. We have demonstrated that pediatric VHEE plans resulted in significant critical organ dose sparing compared to the clinical VMAT plan.

  12. Radioactive EGFR Antibody Cetuximab in Multimodal Cancer Treatment: Stability and Synergistic Effects With Radiotherapy

    SciTech Connect

    Rades, Dirk; Wolff, Christian; Nadrowitz, Roger; Breunig, Christian; Schild, Steven E.; Baehre, Manfred; Meller, Birgit

    2009-11-15

    Purpose: Systemic therapies when added to whole brain radiotherapy have failed to improve the survival of patients with multiple brain metastases. The epidermal growth factor receptor antibody cetuximab is an attractive option, if it is able to cross the blood-brain barrier. This might be proven with molecular imaging if the radiolabeled antibody is stable long enough to be effective. This study investigated the stability of radiolabeled cetuximab (Erbitux) ({sup 131}I-Erbi) and potential synergistic effects with radiotherapy in vitro. Methods and Materials: Two cell lines were investigated, A431 with numerous epidermal growth factor receptors, and JIMT without epidermal growth factor receptors. We labeled 0.4 mg cetuximab with 50 MBq of [{sup 131}I] iodide. Stability was determined for 72 h. The cell cultures were incubated with {sup 131}I-Erbi or cold cetuximab for 72 h. Uptake and cell proliferation were measured every 24 h after no radiotherapy or irradiation with 2, 4, or 10 Gy. Results: The radiolabeling yield of {sup 131}I-Erbi was always >80%. The radiochemical purity was still 93.6% after 72 h. A431 cells showed a {sup 131}I-Erbi uptake about 100-fold greater than the JIMT controls. After 48 h, the A431 cultures showed significantly decreased proliferation. At 72 h after irradiation, {sup 131}I-Erbi resulted in more pronounced inhibition of cell proliferation than the cold antibody in all radiation dose groups. Conclusion: {sup 131}I-Erbi was stable for <=72 h. Radiotherapy led to increased tumor cell uptake of {sup 131}I-Erbi. Radiotherapy and {sup 131}I-Erbi synergistically inhibited tumor cell proliferation. These results provide the prerequisite data for a planned in vivo study of whole brain radiotherapy plus cetuximab for brain metastases.

  13. Evaluating changes in tumor volume using magnetic resonance imaging during the course of radiotherapy treatment of high-grade gliomas: Implications for conformal dose-escalation studies

    SciTech Connect

    Tsien, Christina . E-mail: ctsien@umich.edu; Gomez-Hassan, Diana; Haken, Randall K. ten; Tatro, Daniel C.; Junck, L.; Chenevert, T.L.; Lawrence, T.

    2005-06-01

    Objective: To determine whether changes in tumor volume occur during the course of conformal 3D radiotherapy of high-grade gliomas by use of magnetic resonance imaging (MRI) during treatment and whether these changes had an impact on tumor coverage. Methods and Materials: Between December 2000 and January 2004, 21 patients with WHO Grades 3 to 4 supratentorial malignant gliomas treated with 3D conformal radiotherapy (median dose, 70 Gy) were enrolled in a prospective clinical study. All patients underwent T1-weighted contrast-enhancing and T2-weighted and fluid-attenuated inversion recovery (FLAIR) imaging at approximately 1 to 2 weeks before radiotherapy, during radiotherapy (Weeks 1 and 3), and at routine intervals thereafter. All MRI scans were coregistered to the treatment-planning CT. Gross tumor volume (GTV Pre-Rx) was defined from a postoperative T1-weighted contrast-enhancing MRI performed 1 to 2 weeks before start of radiotherapy. A second GTV (GTV Week 3) was defined by use of an MRI performed during Week 3 of radiotherapy. A uniform 0.5 cm expansion of the respective GTV, PTV (Pre-Rx), and PTV (Week 3) was applied to the final boost plan. Dose-volume histograms (DVH) were used to analyze any potential adverse changes in tumor coverage based on Week 3 MRI. Results: All MRI scans were reviewed independently by a neuroradiologist (DGH). Two patients were noted to have multifocal disease at presentation and were excluded from analysis. In 19 cases, changes in the GTV based on MRI at Week 3 during radiotherapy were as follows: 2 cases had an objective decrease in GTV ({>=}50%); 12 cases revealed a slight decrease in the rim enhancement or changes in cystic appearance of the GTV; 2 cases showed no change in GTV; and 3 cases demonstrated an increase in tumor volume. Both cases with objective decreases in GTV during treatment were Grade 3 tumors. No cases of tumor progression were noted in Grade 3 tumors during treatment. In comparison, three of 12 Grade 4

  14. Evaluating Proton Stereotactic Body Radiotherapy to Reduce Chest Wall Dose in the Treatment of Lung Cancer

    PubMed Central

    Welsh, James; Nguyen, Ngoc; Palmer, Matt; Allen, Pamela K.; Paolini, Michael; Liao, Zhongxing; Bluett, Jaques; Mohan, Radhe; Gomez, Daniel; Cox, James D.; Komaki, Ritsuko; Chang, Joe Y.

    2014-01-01

    Purpose Stereotactic body radiotherapy (SBRT) can produce excellent local control of several types of solid tumor; however, toxicity to nearby critical structures is a concern. We found previously that in SBRT for lung cancer, the chest wall (CW) volume receiving 20, 30, or 40 Gy (V20, V30, or V40) was linked with the development of neuropathy. Here we sought to determine whether the dosimetric advantages of protons could produce lower CW doses than traditional photon-based SBRT. Methods We searched an institutional database to identify patients treated with photon SBRT for lung cancer with tumors within <2.5 cm of the CW. We found 260 cases; of these chronic grade ≥2 CW pain was identified in 23 patients. We then selected 10 representative patients from this group and generated proton SBRT treatment plans, using the identical dose of 50 Gy in 4 fractions, and assessed potential differences in CW dose between the two plans. Results The proton SBRT plans reduced the CW doses at all dose levels measured. The median CW V was 364.0 cm320 for photons and 160.0 cm3 for protons (P<0.0001); V30 was 144.6 cm3 for photons vs. 77.0 cm3 for protons (P=0.0012); V was 93.9 cm335 for photons vs. 57.9 cm3 for protons (P=0.005); V40 was 66.5 cm3 for photons vs. 45.4 cm3 for protons (P=0.0112); and mean lung dose was 5.9 Gy for photons vs. 3.8 Gy for protons (P=0.0001). Coverage of the planning target volume was comparable between the two sets of plans (96.4% for photons and 97% for protons). Conclusions From a dosimetric standpoint, proton SBRT can achieve the same coverage of the PTV while significantly reducing the dose to the CW and lung relative to photon SBRT and therefore may be beneficial for the treatment of lesions close to critical structures. PMID:24200220

  15. Evaluating proton stereotactic body radiotherapy to reduce chest wall dose in the treatment of lung cancer

    SciTech Connect

    Welsh, James; Amini, Arya; Ciura, Katherine; Nguyen, Ngoc; Palmer, Matt; Soh, Hendrick; Allen, Pamela K.; Paolini, Michael; Liao, Zhongxing; Bluett, Jaques; Mohan, Radhe; Gomez, Daniel; Cox, James D.; Komaki, Ritsuko; Chang, Joe Y.

    2013-01-01

    Stereotactic body radiotherapy (SBRT) can produce excellent local control of several types of solid tumor; however, toxicity to nearby critical structures is a concern. We found previously that in SBRT for lung cancer, the chest wall (CW) volume receiving 20, 30, or 40 Gy (V{sub 20}, V{sub 30}, or V{sub 40}) was linked with the development of neuropathy. Here we sought to determine whether the dosimetric advantages of protons could produce lower CW doses than traditional photon-based SBRT. We searched an institutional database to identify patients treated with photon SBRT for lung cancer with tumors within < 2.5 cm of the CW. We found 260 cases; of these, chronic grade ≥ 2 CW pain was identified in 23 patients. We then selected 10 representative patients from this group and generated proton SBRT treatment plans, using the identical dose of 50 Gy in 4 fractions, and assessed potential differences in CW dose between the 2 plans. The proton SBRT plans reduced the CW doses at all dose levels measured. The median CW V{sub 20} was 364.0 cm{sup 3} and 160.0 cm{sup 3} (p < 0.0001), V{sub 30} was 144.6 cm{sup 3}vs 77.0 cm{sup 3} (p = 0.0012), V{sub 35} was 93.9 cm{sup 3}vs 57.9 cm{sup 3} (p = 0.005), V{sub 40} was 66.5 cm{sup 3}vs 45.4 cm{sup 3} (p = 0.0112), and mean lung dose was 5.9 Gy vs 3.8 Gy (p = 0.0001) for photons and protons, respectively. Coverage of the planning target volume (PTV) was comparable between the 2 sets of plans (96.4% for photons and 97% for protons). From a dosimetric standpoint, proton SBRT can achieve the same coverage of the PTV while significantly reducing the dose to the CW and lung relative to photon SBRT and therefore may be beneficial for the treatment of lesions closer to critical structures.

  16. Recommendations for dose calculations of lung cancer treatment plans treated with stereotactic ablative body radiotherapy (SABR)

    NASA Astrophysics Data System (ADS)

    Devpura, S.; Siddiqui, M. S.; Chen, D.; Liu, D.; Li, H.; Kumar, S.; Gordon, J.; Ajlouni, M.; Movsas, B.; Chetty, I. J.

    2014-03-01

    The purpose of this study was to systematically evaluate dose distributions computed with 5 different dose algorithms for patients with lung cancers treated using stereotactic ablative body radiotherapy (SABR). Treatment plans for 133 lung cancer patients, initially computed with a 1D-pencil beam (equivalent-path-length, EPL-1D) algorithm, were recalculated with 4 other algorithms commissioned for treatment planning, including 3-D pencil-beam (EPL-3D), anisotropic analytical algorithm (AAA), collapsed cone convolution superposition (CCC), and Monte Carlo (MC). The plan prescription dose was 48 Gy in 4 fractions normalized to the 95% isodose line. Tumors were classified according to location: peripheral tumors surrounded by lung (lung-island, N=39), peripheral tumors attached to the rib-cage or chest wall (lung-wall, N=44), and centrally-located tumors (lung-central, N=50). Relative to the EPL-1D algorithm, PTV D95 and mean dose values computed with the other 4 algorithms were lowest for "lung-island" tumors with smallest field sizes (3-5 cm). On the other hand, the smallest differences were noted for lung-central tumors treated with largest field widths (7-10 cm). Amongst all locations, dose distribution differences were most strongly correlated with tumor size for lung-island tumors. For most cases, convolution/superposition and MC algorithms were in good agreement. Mean lung dose (MLD) values computed with the EPL-1D algorithm were highly correlated with that of the other algorithms (correlation coefficient =0.99). The MLD values were found to be ~10% lower for small lung-island tumors with the model-based (conv/superposition and MC) vs. the correction-based (pencil-beam) algorithms with the model-based algorithms predicting greater low dose spread within the lungs. This study suggests that pencil beam algorithms should be avoided for lung SABR planning. For the most challenging cases, small tumors surrounded entirely by lung tissue (lung-island type), a Monte

  17. SU-E-T-43: Analytical Model for Photon Peripheral Dose in Radiotherapy Treatments

    SciTech Connect

    Nieto, B Sanchez; El far, R; Romero-Exposito, M; Lagares, J; Mateo, JC; Terron, JA; Irazola, L; Sanchez-Doblado, F

    2014-06-01

    Purpose: The higher survival rate of radiotherapy patients entails a growing concern on second cancers associated to peripheral doses. Currently, dosimetry of out-of field doses is still under development. Our group has developed a methodology to estimate neutron equivalent dose in organs (1,2). We aimed to propose a model to estimate out-of-field photon doses in isocentric treatments from basic clinical data. Methods: The proposed function models the dose as the sum of leakage and scatter terms. The latter is modeled as a virtual source at the collimator, which suffers from attenuation in air and tissue, corrected by the inverse-square-law. The model was parameterized using experimental measurements with TLD700 chips placed inside an anthropomorphic phantom (6–18MV) irradiated with conformal and modulated techniques in Elekta, Siemens and Varian linacs. This model provides photon dose at a point as a function of clinical parameters as prescription dose/UM, PTV volume, distance to the field edge, height of the MLC leaves and distance from the the MLC to the isocenter. Model was tested against independent measurements (TLD100) for a VMAT treatment on a Elekta. Dose to organs is modeled from dose to points along the head-to-feet axis of the organ of a “standard man” escalated by patient height. Results: Our semi-empirical model depends on 3 given parameters (leakage parameter can be individualized). A novelty of our model, over other models (e.g., PERIDOSE), arises from its applicability to any technique (independently of the number of MU needed to deliver a dose). Differences between predictions and measurements were < 0.005mSv/UM. Conclusion: We have proposed a unique model which successfully account for photon peripheral organ dose. This model can be applied in the day-to-day clinic as it only needs a few basic parameters which are readily accessible.1. Radiother. Oncol. 107:234–243, 2013. 2. Phys. Med. Biol. 57:6167–6191, 2012.

  18. Treatment outcome of localized prostate cancer by 70 Gy hypofractionated intensity-modulated radiotherapy with a customized rectal balloon

    PubMed Central

    Kim, Hyunjung; Kim, Jun Won; Hong, Sung Joon; Rha, Koon Ho; Lee, Chang-Geol; Yang, Seung Choul; Choi, Young Deuk; Suh, Chang-Ok

    2014-01-01

    Purpose We aimed to analyze the treatment outcome and long-term toxicity of 70 Gy hypofractionated intensity-modulated radiotherapy (IMRT) for localized prostate cancer using a customized rectal balloon. Materials and Methods We reviewed medical records of 86 prostate cancer patients who received curative radiotherapy between January 2004 and December 2011 at our institution. Patients were designated as low (12.8%), intermediate (20.9%), or high risk (66.3%). Thirty patients received a total dose of 70 Gy in 28 fractions over 5 weeks via IMRT (the Hypo-IMRT group); 56 received 70.2 Gy in 39 fractions over 7 weeks via 3-dimensional conformal radiotherapy (the CF-3DRT group, which served as a reference for comparison). A customized rectal balloon was placed in Hypo-IMRT group throughout the entire radiotherapy course. Androgen deprivation therapy was administered to 47 patients (Hypo-IMRT group, 17; CF-3DRT group, 30). Late genitourinary (GU) and gastrointestinal (GI) toxicity were evaluated according to the Radiation Therapy Oncology Group criteria. Results The median follow-up period was 74.4 months (range, 18.8 to 125.9 months). The 5-year actuarial biochemical relapse-free survival rates for low-, intermediate-, and high-risk patients were 100%, 100%, and 88.5%, respectively, for the Hypo-IMRT group and 80%, 77.8%, and 63.6%, respectively, for the CF-3DRT group (p < 0.046). No patient presented with acute or late GU toxicity ≥grade 3. Late grade 3 GI toxicity occurred in 2 patients (3.6%) in the CF-3DRT group and 1 patient (3.3%) in the Hypo-IMRT group. Conclusion Hypo-IMRT with a customized rectal balloon resulted in excellent biochemical control rates with minimal toxicity in localized prostate cancer patients. PMID:25324991

  19. Validation of in-house treatment planning system software for cobalt-60 teletherapy unit at two radiotherapy installations

    NASA Astrophysics Data System (ADS)

    Mu'minah, I. A. S.; Toresano, L. O. H. Z.; Wibowo, W. E.; Sugiyantari; Pawiro, S. A.

    2016-03-01

    DSSuperDose v.1.0 is an in-house treatment planning system (TPS) developed by Medical Physics and Biophysics Laboratory (LFMB) Universitas Indonesia as a treatment planning software for Cobalt-60 teletherapy unit. The main objective of this study was the validation of in-house TPS calculation as an essential part in quality assurance (QA) of radiotherapy. Validation of an in-house TPS was performed with two Cobalt-60 teletherapy units by comparison between in-house TPS and ISIS TPS and by measurements of absorbed dose. Mean dose deviations between in-house TPS and measurement were (1.97 ± 2.42)% for open field, (1.32 ± 1.30)% for tray field, and (2.91 ± 2.36)% for wedge field treatments. In-house TPS provide optimal planning for open and tray beam conditions with depth fewer than 10 cm (≤ 10 cm) and field sizes up to 20×20 cm2, while for wedge beam conditions with field sizes fewer than the physical size of the wedge. Comparison of in-house TPS and ISIS TPS demonstrated a good match of 96%. From the results, it is concluded that DSSuperDose v.1.0 is adequately accurate for treatment planning of radiotherapy.

  20. Biological treatment processes for fish processing wastewater--a review.

    PubMed

    Chowdhury, Pankaj; Viraraghavan, T; Srinivasan, A

    2010-01-01

    Water consumption in a fish-processing industry and high-strength wastewater from such an industry are of great concern world-wide. Liquid effluent regulations are becoming more stringent day by day. Biological treatment is the best option for such a wastewater. Anaerobic processes such as upflow anaerobic sludge blanket (UASB) reactor, anaerobic filter (AF) and anaerobic fluidized bed (AFB) reactor can achieve high (80-90%) organics removal and produce biogas. Aerobic processes such as activated sludge, rotating biological contactor, trickling filter and lagoons are also suitable for organics removal. Anaerobic digestion followed by an aerobic process is an optimal process option for fish processing wastewater treatment. PMID:19751972

  1. Impact of 18F-Fluoro-2-Deoxyglucose Positron Emission Tomography on Treatment Strategy and Radiotherapy Planning for Stage I-II Hodgkin Disease: A Prospective Multicenter Study

    SciTech Connect

    Pommier, Pascal; Dussart, Sophie; Girinsky, Theodore; Chabaud, Sylvie; Lagrange, Jean Leon; Nguyen, Tan Dat; Beckendorff, Veronique; D'Hombres, Anne; Artignan, Xavier; Bondiau, Pierre Yves; Carrie, Christian; Giammarile, Francesco

    2011-03-01

    Purpose: To quantify the impact of preradiotherapy 18F-fluoro-2-deoxyglucose positron-emission tomography (FDG-PET) on treatment strategy and radiotherapy planning for patients with Stage I/II Hodgkin disease included in a large prospective multicenter study. Patients and Methods: Conventional computed tomography and FDG-PET were performed just before the planned radiotherapy. The radiotherapy plan was first elaborated under blinded conditions for FDG-PET data. Then, the medical staff was asked to confirm or not confirm the treatment strategy and, if appropriate, to modify the radiotherapy plan based on additional information from FDG-PET. Results: Between January 2004 and January 2006, 137 patients were included (124 were available for analysis) in 11 centers (108 adults, 16 children). All but 1 patient had received chemotherapy before inclusion. Prechemotherapy work-up included FDG-PET for 61 patients, and data were available for elaboration of the first radiotherapy plan. Based on preradiotherapy FDG-PET data, the radiotherapy was cancelled in 6 patients (4.8%), and treatment plan modifications occurred in 16 patients (12.9%): total dose (11 patients), CTV volume (5 patients), number of beam incidences (6 patients), and number of CTV (6 patients). The concordance between the treatment strategies with or without preradiotherapy FDG-PET was 82.3%. Concordance results were not significantly different when prechemotherapy PET-CT information was available. Conclusion: Preradiotherapy FDG-PET for treatment planning in Hodgkin lymphoma may lead to significant modification of the treatment strategy and the radiotherapy planning in patients with Stage I or II Hodgkin disease, even in those who have undergone FDG-PET as part of the prechemotherapy work-up.

  2. Phase I/II Trial Evaluating Carbon Ion Radiotherapy for Salvaging Treatment of Locally Recurrent Nasopharyngeal Carcinoma

    PubMed Central

    Kong, Lin; Hu, Jiyi; Guan, Xiyin; Gao, Jing; Lu, Rong; Lu, Jiade J.

    2016-01-01

    Background: Radiation therapy is the mainstay strategy for the treatment of nasopharyngeal cancer (NPC). Intensity-modulated X-ray therapy (IMXT) alone is the current standard for stage I and II NPC. For stage III and IV A/B diseases, concurrent chemotherapy should be provided in addition to IMXT. However, optimal treatment for locally recurrent NPC after previous definitive dose of radiotherapy is lacking. Various techniques including brachytherapy, IMXT, stereotactic radiosurgery or radiotherapy (SRS or SBRT) have been used in the management of locally recurrent NPC. Due to the inherent limitation of these techniques, i.e., limited range of irradiation or over-irradiation to surrounding normal tissues, moderate efficacy has been observed at the cost of severe toxicities. Carbon ion radiotherapy (CIRT) offers potential physical and biological advantages over photon and proton radiotherapy. Due to the inverted dose profile of particle beams and their greater energy deposition within the Bragg peak, precise dose delivery to the target volume(s) without exposing the surrounding organs at risk to extra doses is possible. In addition, CIRT provides an increased relative biological effectiveness (RBE) as compared to photon and proton radiotherapy. Such advantages may translate to improved outcomes after irradiation in terms of disease control in radio-resistant and previously treated, recurrent malignancies. It is therefore reasonable to postulate that recurrent NPC after high-dose radiotherapy could be more resistant to re-irradiation using photons. Reports on the treatment of radio-resistant malignancies in the head and neck region such as melanoma, sarcoma, and adenoid cystic carcinoma (ACC) have demonstrated superior local control rates from CIRT as compared to photon irradiation. Thus patients with recurrent NPC are likely to benefit from the enhanced biological effectiveness of carbon ions. As effective retreatment strategy is lacking for locally recurrent NPC

  3. The feasibility of using a conventional flexible RF coil for an online MR-guided radiotherapy treatment

    NASA Astrophysics Data System (ADS)

    Hoogcarspel, Stan J.; Crijns, Sjoerd P. M.; Lagendijk, Jan J. W.; van Vulpen, Marco; Raaymakers, Bas W.

    2013-03-01

    The purpose of this paper is to evaluate the impact of a flexible radiofrequency coil on the treatment delivery of an online MR-guided radiotherapy treatment. For this study, we used a Synergy MR body coil (Philips, Best) in combination with the current MRL prototype of the UMC Utrecht. The compatibility of the coil is evaluated in two steps. First, we evaluated the dosimetric impact of the MR coil on both a simple and a complex irradiation strategy for treating spinal bone metastases. This tumor site will likely be chosen for the first in-man treatments with the UMC Utrecht MRL system. Second, we investigated the impact of the treatment beam on the MRI performance of the body coil. In case a single posterior-anterior rectangular field was applied, dose to the target volume was underestimated up to 2.2% as a result of beam attenuation in the MR coil. This underestimation however, decreased to 1% when a stereotactic treatment strategy was employed. The presence of the MR coil in or near the distal site of the treatment beam decreased the exit dose when a magnetic field was present. The MRI performance of the coil was unaffected as the result of the radiation. It is feasible to use the Synergy MR body coil for an online MR-guided radiotherapy treatment without any modification to the coil or attenuation correction methods in the planning stage. The effect of the MRI coil on the dose delivery is minimal and there is no effect of the treatment beam on the SNR of the acquired MRI data.

  4. Assessment of Geometrical Accuracy of Multimodal Images Used for Treatment Planning in Stereotactic Radiotherapy and Radiosurgery: CT, MRI and PET

    SciTech Connect

    Garcia-Garduno, O. A.; Larraga-Gutierrez, J. M.; Celis, M. A.; Suarez-Campos, J. J.; Rodriguez-Villafuerte, M.; Martinez-Davalos, A.

    2006-09-08

    An acrylic phantom was designed and constructed to assess the geometrical accuracy of CT, MRI and PET images for stereotactic radiotherapy (SRT) and radiosurgery (SRS) applications. The phantom was suited for each image modality with a specific tracer and compared with CT images to measure the radial deviation between the reference marks in the phantom. It was found that for MRI the maximum mean deviation is 1.9 {+-} 0.2 mm compared to 2.4 {+-} 0.3 mm reported for PET. These results will be used for margin outlining in SRS and SRT treatment planning.

  5. Pros: concurrent chemo-radiotherapy remains the ideal treatment in fit patients with large volume unresectable stage III non-small cell lung cancer

    PubMed Central

    Rabatic, Bryan M.

    2016-01-01

    The debate of treating stage III, large volume non-small cell lung cancer (NSCLC) with definitive chemo-radiotherapy continues to be waged. A physically fit patient, having large volume and unresectable disease is the ideal candidate for this treatment approach. The ability of this patient population to successfully complete, and thereby benefit from an aggressive, combined treatment to improve local control and survival, drives the recommendation of treating oncologists for this approach. Until a phase III trial proves otherwise, concurrent chemo-radiotherapy will remain the ideal treatment for fit patients having large volume unresectable stage III NSCLC. PMID:27186513

  6. Extended field intensity-modulated radiotherapy plus concurrent nedaplatin treatment in cervical cancer

    PubMed Central

    LIU, YUNQIN; YU, JINMING; QIAN, LITING; ZHANG, HONGYAN; MA, JUN

    2016-01-01

    The present study assessed the efficacy and toxicity of definitive extended-field intensity-modulated radiotherapy (EF-IMRT) plus concurrent chemotherapy in cervical cancer. A total of 48 patients with cervical cancer received the planning target volume between 39.6 and 50.4 Gy in 1.8–2.0 Gy daily fractions, while the enlarged pelvic and/or para-aortic nodes were treated with a total dose of 55–60 Gy in 2.0–2.4 Gy daily fractions using simultaneous integrated boost-IMRT. All patients underwent high dose-rate brachytherapy. Concurrent to EF-IMRT, nedaplatin was administered weekly at a median dose of 30 mg/m2 (range, 25–40 mg/m2) for 5 weeks with a total of 150 mg/m2. Of the 48 patients, 46 patients exhibited initial complete responses and 2 patients had partial responses, with a response rate of 100%. After 4–24 months of treatment, 12 patients (27.08%) had local and/or distant failure and 39 patients (81.25%) were alive at the last follow-up. The 12-month overall survival (OS) and disease-free survival (DFS) were 87.5 and 75.8%, respectively, while the 24-month OS and DFS were 69.7 and 49.7%, respectively. Grade ≥3 acute neutropenia and thrombcytopenia occurred in 20 (41.7%) and 4 (8.3%) patients, respectively, while 2 patients (4.2%) developed grade ≥3 diarrhea and 2 (4.2%) had grade ≥3 late toxicities. However, no patients exhibited grade ≥3 vomiting. Thus, concurrent nedaplatin chemotherapy with definitive EF-IMRT was effective and relatively safe for treating patients with cervical cancer. Furthermore, EF-IMRT was able to deliver ≤60 Gy to enlarged para-aortic and/or pelvic nodes using simultaneous integrated boost without increased acute and late gastrointestinal toxicity. PMID:27123128

  7. Integration of surgery with fractionated stereotactic radiotherapy for treatment of nonfunctioning pituitary macroadenomas

    SciTech Connect

    Paek, Sun Ha; Downes, M. Beverly; Bednarz, Greg; Keane, William M.; Werner-Wasik, Maria; Curran, Walter J.; Andrews, David W. . E-mail: david.andrews@jefferson.edu

    2005-03-01

    Objective: To evaluate the efficacy of fractionated stereotactic radiotherapy (FSRT) after surgery in the management of residual or recurrent nonfunctioning pituitary adenomas with respect to tumor control and the development of complications. Methods and materials: The clinical records of patients with nonfunctioning pituitary adenomas who underwent FSRT were retrospectively analyzed. For newly diagnosed tumors, transsphenoidal surgery was performed, and, if residual tumor was identified at 3 months, FSRT was performed. If significant tumor volume persisted, transcranial surgery was performed before FSRT. We originally initiated FSRT with 2-Gy fractions to 46 Gy. We escalated the dose to 50.4 Gy thereafter. As a final modification, we dropped the daily dose to 1.8-Gy fractions delivered within 6 weeks. High-dose conformality and homogeneity was achieved with arc beam shaping and differential beam weighting. The radiographic, endocrinologic, and visual outcomes after FSRT were evaluated. Results: The 68 patients included 36 males and 32 females with an age range of 15-81 years. The median follow-up was 30 months (range, 2-82 months), and the median tumor volume was 6.2 cm{sup 3}. Of the 68 patients, 20 were treated to 46 Gy and 48 to 50-52.2 Gy. Most were treated to 50.4 Gy. Eleven patients had recurrent tumors, 54 had residual tumors, and no surgery was performed in 3 patients before FSRT. We noted no radiation-induced acute or late toxicities, except for radiation-induced optic neuropathy in 2 patients. At latest follow-up, the tumor had decreased in size in 26 patients and remained stable in 41 of the 42 remaining patients. Of the 68 patients, 4 (6%) developed hypopituitarism at 6, 11, 12, and 17 months after FSRT. Reviewing available serial Humphrey visual fields, visual fields were objectively improved in 28 patients, and remained stable in 24 patients, and worsened in 2 patients. Conclusion: The findings of this analysis support the use of surgery followed by

  8. Alternate calibration method of radiochromic EBT3 film for quality assurance verification of clinical radiotherapy treatments

    NASA Astrophysics Data System (ADS)

    Park, Soah; Kang, Sei-Kwon; Cheong, Kwang-Ho; Hwang, Taejin; Yoon, Jai-Woong; Koo, Taeryool; Han, Tae Jin; Kim, Haeyoung; Lee, Me Yeon; Bae, Hoonsik; Kim, Kyoung Ju

    2016-07-01

    EBT3 film is utilized as a dosimetry quality assurance tool for the verification of clinical radiotherapy treatments. In this work, we suggest a percentage-depth-dose (PDD) calibration method that can calibrate several EBT3 film pieces together at different dose levels because photon beams provide different dose levels at different depths along the axis of the beam. We investigated the feasibility of the film PDD calibration method based on PDD data and compared the results those from the traditional film calibration method. Photon beams at 6 MV were delivered to EBT3 film pieces for both calibration methods. For the PDD-based calibration, the film pieces were placed on solid phantoms at the depth of maximum dose (dmax) and at depths of 3, 5, 8, 12, 17, and 22 cm, and a photon beam was delivered twice, at 100 cGy and 400 cGy, to extend the calibration dose range under the same conditions. Fourteen film pieces, to maintain their consistency, were irradiated at doses ranging from approximately 30 to 400 cGy for both film calibrations. The film pieces were located at the center position on the scan bed of an Epson 1680 flatbed scanner in the parallel direction. Intensity-modulated radiation therapy (IMRT) plans were created, and their dose distributions were delivered to the film. The dose distributions for the traditional method and those for the PDD-based calibration method were evaluated using a Gamma analysis. The PDD dose values using a CC13 ion chamber and those obtained by using a FC65-G Farmer chamber and measured at the depth of interest produced very similar results. With the objective test criterion of a 1% dosage agreement at 1 mm, the passing rates for the four cases of the three IMRT plans were essentially identical. The traditional and the PDD-based calibrations provided similar plan verification results. We also describe another alternative for calibrating EBT3 films, i.e., a PDD-based calibration method that provides an easy and time-saving approach

  9. Evaluation of normalized metal artifact reduction (NMAR) in kVCT using MVCT prior images for radiotherapy treatment planning

    SciTech Connect

    Paudel, M. R.; Mackenzie, M.; Rathee, S.; Fallone, B. G.; Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2; Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2

    2013-08-15

    Purpose: To evaluate the metal artifacts in kilovoltage computed tomography (kVCT) images that are corrected using a normalized metal artifact reduction (NMAR) method with megavoltage CT (MVCT) prior images.Methods: Tissue characterization phantoms containing bilateral steel inserts are used in all experiments. Two MVCT images, one without any metal artifact corrections and the other corrected using a modified iterative maximum likelihood polychromatic algorithm for CT (IMPACT) are translated to pseudo-kVCT images. These are then used as prior images without tissue classification in an NMAR technique for correcting the experimental kVCT image. The IMPACT method in MVCT included an additional model for the pair/triplet production process and the energy dependent response of the MVCT detectors. An experimental kVCT image, without the metal inserts and reconstructed using the filtered back projection (FBP) method, is artificially patched with the known steel inserts to get a reference image. The regular NMAR image containing the steel inserts that uses tissue classified kVCT prior and the NMAR images reconstructed using MVCT priors are compared with the reference image for metal artifact reduction. The Eclipse treatment planning system is used to calculate radiotherapy dose distributions on the corrected images and on the reference image using the Anisotropic Analytical Algorithm with 6 MV parallel opposed 5 × 10 cm{sup 2} fields passing through the bilateral steel inserts, and the results are compared. Gafchromic film is used to measure the actual dose delivered in a plane perpendicular to the beams at the isocenter.Results: The streaking and shading in the NMAR image using tissue classifications are significantly reduced. However, the structures, including metal, are deformed. Some uniform regions appear to have eroded from one side. There is a large variation of attenuation values inside the metal inserts. Similar results are seen in commercially corrected image

  10. Nuclear-interaction correction of integrated depth dose in carbon-ion radiotherapy treatment planning.

    PubMed

    Inaniwa, T; Kanematsu, N; Hara, Y; Furukawa, T

    2015-01-01

    1% for all materials and combinations of them. In scanned beams, the dose estimation error in target dose amounted to 4% for a 150 mm-thick layer of 40% K2HPO4. The error is significantly reduced with the correction method. The planned dose distributions with the method agreed with the measurements within ±1.5% of target dose for all materials not only in the target region but also in the plateau and fragment-tail regions. We tested the correction method of IDD in some non-water materials to verify that this method would offer the accuracy and simplicity required in carbon-ion radiotherapy treatment planning. PMID:25658006

  11. 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

  12. Quality Assurance in Radiotherapy

    NASA Astrophysics Data System (ADS)

    Mckenzie, Alan

    A common feature of the Radiotherapy Centres where there have been major accidents involving incorrect radiotherapy treatment is that they did not operate good Quality Assurance systems. A Quality Assurance system is sometimes called a Quality Management system, and it is designed to give assurance that quality standards are being met. One of the "spin offs" from operating a Quality Management system is that it reduces the likelihood of a radiotherapy accident. A detailed account of how to set up a quality system in radiotherapy has been given in an ESTRO booklet.2

  13. A meta-analysis of surgery versus conventional radiotherapy for the treatment of metastatic spinal epidural disease

    PubMed Central

    Klimo, Paul; Thompson, Clinton J.; Kestle, John R.W.; Schmidt, Meic H.

    2005-01-01

    Radiotherapy has been the primary therapy for managing metastatic spinal disease; however, surgery that decompresses the spinal cord circumferentially, followed by reconstruction and immediate stabilization, has also proven effective. We provide a quantitative comparison between the “new” surgery and radiotherapy, based on articles that report on ambulatory status before and after treatment, age, sex, primary neoplasm pathology, and spinal disease distribution. Ambulation was categorized as “success” or “rescue” (proportion of patients ambulatory after treatment and proportion regaining ambulatory function, respectively). Secondary outcomes were also analyzed. We calculated cumulative success and rescue rates for our ambulatory measurements and quantified heterogeneity using a mixed-effects model. We investigated the source of the heterogeneity in both a univariate and multivariate manner with a meta-regression model. Our analysis included data from 24 surgical articles (999 patients) and 4 radiation articles (543 patients), mostly uncontrolled cohort studies (Class III). Surgical patients were 1.3 times more likely to be ambulatory after treatment and twice as likely to regain ambulatory function. Overall ambulatory success rates for surgery and radiation were 85% and 64%, respectively. Primary pathology was the principal factor determining survival. We present the first known formal meta-analysis using data from nonrandomized clinical studies. Although we attempted to control for imbalances between the surgical and radiation groups, significant heterogeneity undoubtedly still exists. Nonetheless, we believe the differences in the outcomes indicate a true difference resulting from treatment. We conclude that surgery should usually be the primary treatment with radiation given as adjuvant therapy. Neurologic status, overall health, extent of disease (spinal and extraspinal), and primary pathology all impact proper treatment selection. PMID:15701283

  14. Solid waste treatment processes for space station

    NASA Technical Reports Server (NTRS)

    Marrero, T. R.

    1983-01-01

    The purpose of this study was to evaluate the state-of-the-art of solid waste(s) treatment processes applicable to a Space Station. From the review of available information a source term model for solid wastes was determined. An overall system is proposed to treat solid wastes under constraints of zero-gravity and zero-leakage. This study contains discussion of more promising potential treatment processes, including supercritical water oxidation, wet air (oxygen) oxidation, and chemical oxidation. A low pressure, batch-type treament process is recommended. Processes needed for pretreatment and post-treatment are hardware already developed for space operations. The overall solid waste management system should minimize transfer of wastes from their collection point to treatment vessel.

  15. Consideration of the radiation dose delivered away from the treatment field to patients in radiotherapy

    PubMed Central

    Taylor, Michael L.; Kron, Tomas

    2011-01-01

    Radiation delivery to cancer patients for radiotherapy is invariably accompanied by unwanted radiation to other parts of the patient’s body. Traditionally, considerable effort has been made to calculate and measure the radiation dose to the target as well as to nearby critical structures. Only recently has attention been focused also on the relatively low doses that exist far from the primary radiation beams. In several clinical scenarios, such doses have been associated with cardiac toxicity as well as an increased risk of secondary cancer induction. Out-of-field dose is a result of leakage and scatter and generally difficult to predict accurately. The present review aims to present existing data, from measurements and calculations, and discuss its implications for radiotherapy. PMID:21731221

  16. A Review of Radiotherapy-Induced Late Effects Research after Advanced Technology Treatments

    PubMed Central

    Newhauser, Wayne D.; de Gonzalez, Amy Berrington; Schulte, Reinhard; Lee, Choonsik

    2016-01-01

    The number of incident cancers and long-term cancer survivors is expected to increase substantially for at least a decade. Advanced technology radiotherapies, e.g., using beams of protons and photons, offer dosimetric advantages that theoretically yield better outcomes. In general, evidence from controlled clinical trials and epidemiology studies are lacking. To conduct these studies, new research methods and infrastructure will be needed. In the paper, we review several key research methods of relevance to late effects after advanced technology proton-beam and photon-beam radiotherapies. In particular, we focus on the determination of exposures to therapeutic and stray radiation and related uncertainties, with discussion of recent advances in exposure calculation methods, uncertainties, in silico studies, computing infrastructure, electronic medical records, and risk visualization. We identify six key areas of methodology and infrastructure that will be needed to conduct future outcome studies of radiation late effects. PMID:26904500

  17. Time delay measurement for linac based treatment delivery in synchronized respiratory gating radiotherapy.

    PubMed

    Jin, Jian-Yue; Yin, Fang-Fang

    2005-05-01

    A time delay in a respiratory gating system could cause an unexpected phase mismatch for synchronized gating radiotherapy. This study presents a method of identifying and measuring the time delay in a gating system. Various port films were taken for a motion phantom at different gating window levels with a very narrow window size. The time delay for the gating system was determined by comparing the motion curve (the position of a moving object versus the gating time) measured in the port films to the motion curve determined by the video cameras. The measured time delay for a linac-based gating system was 0.17+/-0.03 s. This time delay could induce target missing if it was not properly taken into account for the synchronized gating radiotherapy. Measurement/verification of the time delay should be considered as an important part of the accepting/commissioning test before the clinical use of the gating system. PMID:15984681

  18. Stereotactic ablative radiotherapy in the treatment of hepatocellular carcinoma >3 cm.

    PubMed

    Guarneri, Alessia; Franco, Pierfrancesco; Trino, Elisabetta; Campion, Daniela; Faletti, Riccardo; Mirabella, Stefano; Gaia, Silvia; Ragona, Riccardo; Diotallevi, Margherita; Saracco, Giorgio; Salizzoni, Mauro; Ricardi, Umberto; Carucci, Patrizia

    2016-10-01

    Stereotactic ablative radiotherapy (SABR) is a safe treatment approach for hepatocellular carcinoma (HCC) with comparable results to other local therapies. For lesions larger than 3 cm, no definitive standard treatment is present and several options are available. We retrospectively review local control (LC) and survival results of SABR in patients with HCC lesions >3 cm. Between 2012 and 2015, we treated 29 patients (39 lesions) having histological or radiological diagnosis of HCC and at least one lesion sized >3 cm. Patients were prescribed 36-48 Gy in 3-5 fractions (mainly 16 Gy × 3 fractions or 8 Gy × 5 fractions), in 3-5 consecutive days. A total of 15 lesions (52 %) had complete, while 10 (34 %) had partial remission; 3 (11 %) had a stable disease. Mean time for CR achievement was 5.8 months (range 1-17). One- and two-year actuarial LC was 100 %. Moreover, 1- and 2-year progression-free (PFS), cancer-specific and overall survival were 57.9 % [standard error (SE) 0.09; 95 % CI 36.9-74.2] and 41.2 % (SE 0.12; 95 % CI 17.7-63.5), 80.7 % (SE 0.08; 95 % CI 59.6-91.5) and 63.3 % (SE 0.11; 95 % CI 38.4-80.3), 71.7 % (SE 0.08; 95 % CI 51.2-84.7) and 56.2 % (SE 0.10; 95 % CI 33.8-73.6). On multivariate analysis, achieving a CR within the target lesion had a borderline significance with respect to PFS (HR 0.83; SE = 0.014; z -1.15; p = 0.095; 95 % CI 0.71-7.45). Time between HCC diagnosis and SABR delivery (< vs >12 months) was significantly correlated with OS (HR 16.5; SE 21.5; z = 2.14; p = 0.032; 95 % CI 1.27-213.3) as CLIP score (score: 0-1 vs 2) (HR 5.6; SE 4.6; z = 2.10; p = 0.036; 95 % CI 1.11-27.8). A total of 6 major toxic events (G3-G4) were recorded (20 %). In 2 patients (6 %), a radiation-induced liver disease was seen. In conclusion, SABR provided LC and survival rates comparable to other local therapies for patients with HCC lesion sized >3 cm, with acceptable toxicity profile. PMID:27566310

  19. Effects of postoperative adjuvant chemotherapy and radiotherapy on ovarian function in women undergoing treatment for soft tissue sarcoma

    SciTech Connect

    Shamberger, R.C.; Sherins, R.J.; Ziegler, J.L.; Glatstein, E.; Rosenberg, S.A.

    1981-12-01

    Ovarian function was evaluated in 11 women 16 to 43 years of age at treatment who received doxorubicin, cyclophosphamide, and high doses of methotrexate with or without radiotherapy in adjuvant therapy of soft tissue sarcoma. Five women (16-33 yr old) who received chemotherapy alone or combined with radiotherapy only at sites distant from the ovaries (chest wall, thigh, and leg) had minimal menstrual irregularities or temporary cessation of menses during therapy; cyclic menses returned promptly after therapy. Gonadotropin levels (expressed as means +/- SD (follicle-stimulating hormone (FSH), 10 +/- 5 mlU/ml; luteinizing hormone (LH), 10 +/- 4 mlU/ml) and 17 beta-estradiol (E2) levels (means +/- SD, 208 +/- 147 pg/ml) were normal. By contrast, 4 older women (ages 36-43 yr) who received similar treatment developed persistent amenorrhea with postmenopausal levels of gonadotropin (FSH, 108 +/- 29 mlU/ml; LH, 72 +/- 19 mlU/ml) and E2 (19 +/- 8 pg/ml). Two additional women (ages 21 and 39 yr) who received radiation (7,000 rad) to the pelvis plus chemotherapy developed prompt cessation of menses and became functional castrates (FSH, 77 and 80 mlU/ml; LH, 40 and 58 mlU/ml; E2, 10 and 19 pg/ml). However, this result would be expected from the radiation dose alone. The data demonstrated that ovarian dysfunction may follow the use of doxorubicin, cyclophosphamide, and high doses of methotrexate and that the injury is age related.

  20. Perspectives on the combination of radiotherapy and targeted therapy with DNA repair inhibitors in the treatment of pancreatic cancer

    PubMed Central

    Yang, Shih-Hung; Kuo, Ting-Chun; Wu, Hsu; Guo, Jhe-Cyuan; Hsu, Chiun; Hsu, Chih-Hung; Tien, Yu-Wen; Yeh, Kun-Huei; Cheng, Ann-Lii; Kuo, Sung-Hsin

    2016-01-01

    Pancreatic cancer is highly lethal. Current research that combines radiation with targeted therapy may dramatically improve prognosis. Cancerous cells are characterized by unstable genomes and activation of DNA repair pathways, which are indicated by increased phosphorylation of numerous factors, including H2AX, ATM, ATR, Chk1, Chk2, DNA-PKcs, Rad51, and Ku70/Ku80 heterodimers. Radiotherapy causes DNA damage. Cancer cells can be made more sensitive to the effects of radiation (radiosensitization) through inhibition of DNA repair pathways. The synergistic effects, of two or more combined non-lethal treatments, led to co-administration of chemotherapy and radiosensitization in BRCA-defective cells and patients, with promising results. ATM/Chk2 and ATR/Chk1 pathways are principal regulators of cell cycle arrest, following DNA double-strand or single-strand breaks. DNA double-stranded breaks activate DNA-dependent protein kinase, catalytic subunit (DNA-PKcs). It forms a holoenzyme with Ku70/Ku80 heterodimers, called DNA-PK, which catalyzes the joining of nonhomologous ends. This is the primary repair pathway utilized in human cells after exposure to ionizing radiation. Radiosensitization, induced by inhibitors of ATM, ATR, Chk1, Chk2, Wee1, PP2A, or DNA-PK, has been demonstrated in preclinical pancreatic cancer studies. Clinical trials are underway. Development of agents that inhibit DNA repair pathways to be clinically used in combination with radiotherapy is warranted for the treatment of pancreatic cancer. PMID:27621574

  1. Perspectives on the combination of radiotherapy and targeted therapy with DNA repair inhibitors in the treatment of pancreatic cancer.

    PubMed

    Yang, Shih-Hung; Kuo, Ting-Chun; Wu, Hsu; Guo, Jhe-Cyuan; Hsu, Chiun; Hsu, Chih-Hung; Tien, Yu-Wen; Yeh, Kun-Huei; Cheng, Ann-Lii; Kuo, Sung-Hsin

    2016-08-28

    Pancreatic cancer is highly lethal. Current research that combines radiation with targeted therapy may dramatically improve prognosis. Cancerous cells are characterized by unstable genomes and activation of DNA repair pathways, which are indicated by increased phosphorylation of numerous factors, including H2AX, ATM, ATR, Chk1, Chk2, DNA-PKcs, Rad51, and Ku70/Ku80 heterodimers. Radiotherapy causes DNA damage. Cancer cells can be made more sensitive to the effects of radiation (radiosensitization) through inhibition of DNA repair pathways. The synergistic effects, of two or more combined non-lethal treatments, led to co-administration of chemotherapy and radiosensitization in BRCA-defective cells and patients, with promising results. ATM/Chk2 and ATR/Chk1 pathways are principal regulators of cell cycle arrest, following DNA double-strand or single-strand breaks. DNA double-stranded breaks activate DNA-dependent protein kinase, catalytic subunit (DNA-PKcs). It forms a holoenzyme with Ku70/Ku80 heterodimers, called DNA-PK, which catalyzes the joining of nonhomologous ends. This is the primary repair pathway utilized in human cells after exposure to ionizing radiation. Radiosensitization, induced by inhibitors of ATM, ATR, Chk1, Chk2, Wee1, PP2A, or DNA-PK, has been demonstrated in preclinical pancreatic cancer studies. Clinical trials are underway. Development of agents that inhibit DNA repair pathways to be clinically used in combination with radiotherapy is warranted for the treatment of pancreatic cancer. PMID:27621574

  2. Apparatus and process for water treatment

    DOEpatents

    Phifer, Mark A.; Nichols, Ralph L.

    2001-01-01

    An apparatus is disclosed utilizing permeable treatment media for treatment of contaminated water, along with a method for enhanced passive flow of contaminated water through the treatment media. The apparatus includes a treatment cell including a permeable structure that encloses the treatment media, the treatment cell may be located inside a water collection well, exterior to a water collection well, or placed in situ within the pathway of contaminated groundwater. The passive flow of contaminated water through the treatment media is maintained by a hydraulic connection between a collecting point of greater water pressure head, and a discharge point of lower water pressure head. The apparatus and process for passive flow and groundwater treatment utilizes a permeable treatment media made up of granular metal, bimetallics, granular cast iron, activated carbon, cation exchange resins, and/or additional treatment materials. An enclosing container may have an outer permeable wall for passive flow of water into the container and through the enclosed treatment media to an effluent point. Flow of contaminated water is attained without active pumping of water through the treatment media. Remediation of chlorinated hydrocarbons and other water contaminants to acceptable regulatory concentration levels is accomplished without the costs of pumping, pump maintenance, and constant oversight by personnel.

  3. Progressive Muscle Atrophy and Weakness After Treatment by Mantle Field Radiotherapy in Hodgkin Lymphoma Survivors

    SciTech Connect

    Leeuwen-Segarceanu, Elena M. van; Dorresteijn, Lucille D.A.; Pillen, Sigrid; Biesma, Douwe H.; Vogels, Oscar J.M.; Alfen, Nens van

    2012-02-01

    Purpose: To describe the damage to the muscles and propose a pathophysiologic mechanism for muscle atrophy and weakness after mantle field radiotherapy in Hodgkin lymphoma (HL) survivors. Methods and Materials: We examined 12 patients treated by mantle field radiotherapy between 1969 and 1998. Besides evaluation of their symptoms, the following tests were performed: dynamometry; ultrasound of the sternocleidomastoid, biceps, and antebrachial flexor muscles; and needle electromyography of the neck, deltoid, and ultrasonographically affected arm muscles. Results: Ten patients (83%) experienced neck complaints, mostly pain and muscle weakness. On clinical examination, neck flexors were more often affected than neck extensors. On ultrasound, the sternocleidomastoid was severely atrophic in 8 patients, but abnormal echo intensity was seen in only 3 patients. Electromyography of the neck muscles showed mostly myogenic changes, whereas the deltoid, biceps, and antebrachial flexor muscles seemed to have mostly neurogenic damage. Conclusions: Many patients previously treated by mantle field radiotherapy develop severe atrophy and weakness of the neck muscles. Neck muscles within the radiation field show mostly myogenic damage, and muscles outside the mantle field show mostly neurogenic damage. The discrepancy between echo intensity and atrophy suggests that muscle damage is most likely caused by an extrinsic factor such as progressive microvascular fibrosis. This is also presumed to cause damage to nerves within the radiated field, resulting in neurogenic damage of the deltoid and arm muscles.

  4. Analysis of a large number of clinical studies for breast cancer radiotherapy: estimation of radiobiological parameters for treatment planning

    NASA Astrophysics Data System (ADS)

    Guerrero, M.; Li, X. Allen

    2003-10-01

    Numerous studies of early-stage breast cancer treated with breast conserving surgery (BCS) and radiotherapy (RT) have been published in recent years. Both external beam radiotherapy (EBRT) and/or brachytherapy (BT) with different fractionation schemes are currently used. The present RT practice is largely based on empirical experience and it lacks a reliable modelling tool to compare different RT modalities or to design new treatment strategies. The purpose of this work is to derive a plausible set of radiobiological parameters that can be used for RT treatment planning. The derivation is based on existing clinical data and is consistent with the analysis of a large number of published clinical studies on early-stage breast cancer. A large number of published clinical studies on the treatment of early breast cancer with BCS plus RT (including whole breast EBRT with or without a boost to the tumour bed, whole breast EBRT alone, brachytherapy alone) and RT alone are compiled and analysed. The linear quadratic (LQ) model is used in the analysis. Three of these clinical studies are selected to derive a plausible set of LQ parameters. The potential doubling time is set a priori in the derivation according to in vitro measurements from the literature. The impact of considering lower or higher Tpot is investigated. The effects of inhomogeneous dose distributions are considered using clinically representative dose volume histograms. The derived LQ parameters are used to compare a large number of clinical studies using different regimes (e.g., RT modality and/or different fractionation schemes with different prescribed dose) in order to validate their applicability. The values of the equivalent uniform dose (EUD) and biologically effective dose (BED) are used as a common metric to compare the biological effectiveness of each treatment regime. We have obtained a plausible set of radiobiological parameters for breast cancer: agr = 0.3 Gy-1, agr/bgr = 10 Gy and sub

  5. 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

  6. Radiotherapy in the treatment of mucosal melanoma of the upper aerodigestive tract: Analysis of 74 cases. A Rare Cancer Network study

    SciTech Connect

    Krengli, Marco . E-mail: krengli@tera.it; Masini, Laura; Kaanders, Johannes; Maingon, Philippe; Oei, Swan Bing; Zouhair, Abderrahim; Ozyar, Enis; Roelandts, Martine; Amichetti, Maurizio; Bosset, Mathieu; Mirimanoff, Rene-Olivier

    2006-07-01

    Purpose: To retrospectively analyze a series of mucosal melanoma of the upper aerodigestive tract to determine the prognostic factors and contribute to understanding the role of radiotherapy in the therapeutic strategy. Methods and Materials: Seventy-four patients were analyzed. The most frequent locations were nasal and oral, in 31 patients (41.9%) and 12 patients (16.2%), respectively. Sixty-three patients (85.1%) were in Stage I, 5 (6.8%) in Stage II, and 6 (8.1%) in Stage III. Treatment consisted of surgery in 17 patients (23.0%), surgery and radiotherapy in 42 (56.8%), radiotherapy in 11 (14.9%), and chemo-immunotherapy in 4 (5.4%). Median follow-up was 20 months. Results: Local control at 3 years was 57% after surgery alone and 71% after surgery and radiotherapy. Overall and disease-free survival rates, respectively, were 41% and 31% at 3 years and 14% and 22% at 10 years. After univariate analysis, female gender, melanosis, tumor size {<=}3 cm, Stage I, postoperative radiotherapy, and complete remission were favorable prognostic factors. Stage I and melanosis were confirmed by multivariate analysis. Conclusions: Local control was improved by postoperative radiotherapy, despite survival being as poor as in other published series. Stage I and melanosis at diagnosis were the most favorable prognostic factors.

  7. Salvage endoscopic resection as a treatment for locoregional failure or recurrence following chemoradiotherapy or radiotherapy for esophageal cancer

    PubMed Central

    NAKAMURA, RIEKO; OMORI, TAI; TAKEUCHI, HIROYA; KAWAKUBO, HIROFUMI; TAKAHASHI, TSUNEHIRO; WADA, NORIHITO; SAIKAWA, YOSHIRO; KITAGAWA, YUKO

    2016-01-01

    Radiotherapy (RT) or chemoradiotherapy (CRT) is a potentially curative, non-surgical treatment option for esophageal cancer, although the rate of local failure within the esophagus remains relatively high. Salvage esophagectomy is not regarded as a common treatment for esophageal cancer, since it is a high-risk surgery with a relatively high surgical mortality rate. Salvage endoscopic resection (ER) for local failure is used for treatment when esophageal cancer is localized and superficial. To evaluate to usefulness of salvage ER, the present study reviewed the clinicopathological records and follow-up data of 37 patients that underwent salvage ER for esophageal cancer, following initial treatment with RT or CRT. Salvage ER was conducted on a total of 78 lesions observed in the 37 patients. Since a thick epithelium and lack of normal vessels on the surface of the mucosa are characteristics of esophageal mucosa following RT or CRT, almost all the lesions were detected using iodine dyeing, and not by narrow band imaging. The growth rate of the detected lesions was relatively high, and early treatment was required. No particular complications occurred during the endoscopic treatment. A total of 11 patients survived for >5 years subsequent to initial endoscopic treatment. Only 4 patients succumbed to esophageal cancer. In conclusion, the present study demonstrated that salvage ER following CRT or RT for esophageal cancer is a minimally invasive, safe, adaptive and curative method for superficial lesions without distant metastases in patients with esophageal cancer with local failure following CRT or RT. PMID:27284365

  8. Comparative evaluation of a novel 3D segmentation algorithm on in-treatment radiotherapy cone beam CT images

    NASA Astrophysics Data System (ADS)

    Price, Gareth; Moore, Chris

    2007-03-01

    Image segmentation and delineation is at the heart of modern radiotherapy, where the aim is to deliver as high a radiation dose as possible to a cancerous target whilst sparing the surrounding healthy tissues. This, of course, requires that a radiation oncologist dictates both where the tumour and any nearby critical organs are located. As well as in treatment planning, delineation is of vital importance in image guided radiotherapy (IGRT): organ motion studies demand that features across image databases are accurately segmented, whilst if on-line adaptive IGRT is to become a reality, speedy and correct target identification is a necessity. Recently, much work has been put into the development of automatic and semi-automatic segmentation tools, often using prior knowledge to constrain some grey level, or derivative thereof, interrogation algorithm. It is hoped that such techniques can be applied to organ at risk and tumour segmentation in radiotherapy. In this work, however, we make the assumption that grey levels do not necessarily determine a tumour's extent, especially in CT where the attenuation coefficient can often vary little between cancerous and normal tissue. In this context we present an algorithm that generates a discontinuity free delineation surface driven by user placed, evidence based support points. In regions of sparse user supplied information, prior knowledge, in the form of a statistical shape model, provides guidance. A small case study is used to illustrate the method. Multiple observers (between 3 and 7) used both the presented tool and a commercial manual contouring package to delineate the bladder on a serially imaged (10 cone beam CT volumes ) prostate patient. A previously presented shape analysis technique is used to quantitatively compare the observer variability.

  9. A Treatment Planning Study of Stereotactic Body Radiotherapy for Atrial Fibrillation

    PubMed Central

    Kotecha, Rupesh; Sharma, Naveen; Andrews, Martin; Stephans, Kevin L; Oberti, Carlos; Lin, Sara; Wazni, Oussama; Tchou, Patrick; Saliba, Walid I; Suh, John

    2016-01-01

    Purpose: To explore the feasibility of using stereotactic body radiotherapy (SBRT) to irradiate the antra of the four pulmonary veins while protecting nearby critical organs, such as the esophagus. Materials and Methods: Twenty patients who underwent radiofrequency catheter ablation for atrial fibrillation were selected. For each patient, the antra of the four pulmonary veins were identified as the target volumes on a pre-catheterization contrast or non-contrast CT scan. On each CT scan, the esophagus, trachea, heart, and total lung were delineated and the esophagus was identified as the critical organ. For each patient, three treatment plans were designed with 0, 2, and 5 mm planning margins around the targets while avoiding overlap with a planning organ at risk volume (PRV) generated by a 2 mm expansion of the esophagus. Using three non-coplanar volumetric modulated arcs (VMAT), 60 plans were created to deliver a prescription dose of 50 Gy in five fractions, following the SBRT dose regimen for central lung tumors. With greater than 97% of the planning target volumes (PTV) receiving the prescription doses, we examined dosimetry to 0.03 cc and 5 cc of the esophagus PRV volume as well as other contoured structures. Results: The average PTV-0 mm, PTV-2 mm, and PTV-5 mm volumes were 3.05 ± 1.90 cc, 14.70 ± 5.00 cc, and 40.85 ± 10.20 cc, respectively. With three non-coplanar VMAT arcs, the average conformality indices (ratio of prescription isodose volume to the PTV volume) for the PTV-0 mm, PTV-2 mm and PTV-5 mm were 4.81 ± 2.0, 1.71 ± 0.19, and 1.23 ± 0.08, respectively. Assuming patients were treated under breath-hold with 2 mm planning margins to account for cardiac motion, all plans met esophageal PRV maximum dose limits < 50 Gy to 0.03 cc and 16 plans (80%) met < 27.5 Gy to 5 cc of the esophageal PRVs. For PTV-5 mm plans, 18 plans met the maximum dose limit < 50 Gy to 0.03 cc and only two plans met the maximum dose limit < 27.5 Gy to 5 cc of the

  10. Process for the treatment of lignocellulosic biomass

    DOEpatents

    Dale, Bruce E.; Lynd, Lee R.; Laser, Mark

    2013-03-12

    A process for the treatment of biomass to render structural carbohydrates more accessible and/or digestible using concentrated ammonium hydroxide with or without anhydrous ammonia addition, is described. The process preferably uses steam to strip ammonia from the biomass for recycling. The process yields of monosaccharides from the structural carbohydrates are good, particularly as measured by the enzymatic hydrolysis of the structural carbohydrates. The monosaccharides are used as animal feeds and energy sources for ethanol production.

  11. Process for the treatment of lignocellulosic biomass

    SciTech Connect

    Dale, Bruce E.

    2014-07-08

    A process for the treatment of biomass to render structural carbohydrates more accessible and/or digestible using concentrated ammonium hydroxide with or without anhydrous ammonia addition, is described. The process preferably uses steam to strip ammonia from the biomass for recycling. The process yields of monosaccharides from the structural carbohydrates are good, particularly as measured by the enzymatic hydrolysis of the structural carbohydrates. The monosaccharides are used as animal feeds and energy sources for ethanol production.

  12. Using a thermoluminescent dosimeter to evaluate the location reliability of the highest–skin dose area detected by treatment planning in radiotherapy for breast cancer

    SciTech Connect

    Sun, Li-Min; Huang, Chih-Jen; Chen, Hsiao-Yun; Meng, Fan-Yun; Lu, Tsung-Hsien; Tsao, Min-Jen

    2014-01-01

    Acute skin reaction during adjuvant radiotherapy for breast cancer is an inevitable process, and its severity is related to the skin dose. A high–skin dose area can be speculated based on the isodose distribution shown on a treatment planning. To determine whether treatment planning can reflect high–skin dose location, 80 patients were collected and their skin doses in different areas were measured using a thermoluminescent dosimeter to locate the highest–skin dose area in each patient. We determined whether the skin dose is consistent with the highest-dose area estimated by the treatment planning of the same patient. The χ{sup 2} and Fisher exact tests revealed that these 2 methods yielded more consistent results when the highest-dose spots were located in the axillary and breast areas but not in the inframammary area. We suggest that skin doses shown on the treatment planning might be a reliable and simple alternative method for estimating the highest skin doses in some areas.

  13. MR-guided pulsed high intensity focused ultrasound enhancement of docetaxel combined with radiotherapy for prostate cancer treatment

    NASA Astrophysics Data System (ADS)

    Mu, Zhaomei; Ma, C.-M.; Chen, Xiaoming; Cvetkovic, Dusica; Pollack, Alan; Chen, Lili

    2012-01-01

    The purpose of this study is to evaluate the efficacy of the enhancement of docetaxel by pulsed focused ultrasound (pFUS) in combination with radiotherapy (RT) for treatment of prostate cancer in vivo. LNCaP cells were grown in the prostates of male nude mice. When the tumors reached a designated volume by MRI, tumor bearing mice were randomly divided into seven groups (n = 5): (1) pFUS alone; (2) RT alone; (3) docetaxel alone; (4) docetaxel + pFUS (5) docetaxel + RT (6) docetaxel + pFUS + RT, and (7) control. MR-guided pFUS treatment was performed using a focused ultrasound treatment system (InSightec ExAblate 2000) with a 1.5T GE MR scanner. Animals were treated once with pFUS, docetaxel, RT or their combinations. Docetaxel was given by i.v. injection at 5 mg kg-1 before pFUS. RT was given 2 Gy after pFUS. Animals were euthanized 4 weeks after treatment. Tumor volumes were measured on MRI at 1 and 4 weeks post-treatment. Results showed that triple combination therapies of docetaxel, pFUS and RT provided the most significant tumor growth inhibition among all groups, which may have potential for the treatment of prostate cancer due to an improved therapeutic ratio.

  14. Optimization of Stereotactic Radiotherapy Treatment Delivery Technique for Base-Of-Skull Meningiomas

    SciTech Connect

    Clark, Brenda G. Candish, Charles; Vollans, Emily; Gete, Ermias; Lee, Richard; Martin, Monty; Ma, Roy; McKenzie, Michael

    2008-10-01

    This study compares static conformal field (CF), intensity modulated radiotherapy (IMRT), and dynamic arcs (DA) for the stereotactic radiotherapy of base-of-skull meningiomas. Twenty-one cases of base-of-skull meningioma (median planning target volume [PTV] = 21.3 cm{sup 3}) previously treated with stereotactic radiotherapy were replanned with each technique. The plans were compared for Radiation Therapy Oncology Group conformity index (CI) and homogeneity index (HI), and doses to normal structures at 6 dose values from 50.4 Gy to 5.6 Gy. The mean CI was 1.75 (CF), 1.75 (DA), and 1.66 (IMRT) (p < 0.05 when comparing IMRT to either CF or DA plans). The CI (IMRT) was inversely proportional to the size of the PTV (Spearman's rho = -0.53, p = 0.01) and at PTV sizes above 25 cm{sup 3}, the CI (IMRT) was always superior to CI (DA) and CI (CF). At PTV sizes below 25 cm{sup 3}, there was no significant difference in CI between each technique. There was no significant difference in HI between plans. The total volume of normal tissue receiving 50.4, 44.8, and 5.6 Gy was significantly lower when comparing IMRT to CF and DA plans (p < 0.05). There was significantly improved dose sparing for the brain stem and ipsilateral temporal lobe with IMRT but no significant difference for the optic chiasm or pituitary gland. These results demonstrate that stereotactic IMRT should be considered to treat base-of-skull meningiomas with a PTV larger than 25 cm{sup 3}, due to improved conformity and normal tissue sparing, in particular for the brain stem and ipsilateral temporal lobe.

  15. Optimization of stereotactic radiotherapy treatment delivery technique for base-of-skull meningiomas.

    PubMed

    Clark, Brenda G; Candish, Charles; Vollans, Emily; Gete, Ermias; Lee, Richard; Martin, Monty; Ma, Roy; McKenzie, Michael

    2008-01-01

    This study compares static conformal field (CF), intensity modulated radiotherapy (IMRT), and dynamic arcs (DA) for the stereotactic radiotherapy of base-of-skull meningiomas. Twenty-one cases of base-of-skull meningioma (median planning target volume [PTV] = 21.3 cm3) previously treated with stereotactic radiotherapy were replanned with each technique. The plans were compared for Radiation Therapy Oncology Group conformity index (CI) and homogeneity index (HI), and doses to normal structures at 6 dose values from 50.4 Gy to 5.6 Gy. The mean CI was 1.75 (CF), 1.75 (DA), and 1.66 (IMRT) (p < 0.05 when comparing IMRT to either CF or DA plans). The CI (IMRT) was inversely proportional to the size of the PTV (Spearman's rho = -0.53, p = 0.01) and at PTV sizes above 25 cm3, the CI (IMRT) was always superior to CI (DA) and CI (CF). At PTV sizes below 25 cm3, there was no significant difference in CI between each technique. There was no significant difference in HI between plans. The total volume of normal tissue receiving 50.4, 44.8, and 5.6 Gy was significantly lower when comparing IMRT to CF and DA plans (p < 0.05). There was significantly improved dose sparing for the brain stem and ipsilateral temporal lobe with IMRT but no significant difference for the optic chiasm or pituitary gland. These results demonstrate that stereotactic IMRT should be considered to treat base-of-skull meningiomas with a PTV larger than 25 cm3, due to improved conformity and normal tissue sparing, in particular for the brain stem and ipsilateral temporal lobe. PMID:18674690

  16. Neutron measurements with ultra-thin 3D silicon sensors in a radiotherapy treatment room using a Siemens PRIMUS linac

    NASA Astrophysics Data System (ADS)

    Guardiola, C.; Gómez, F.; Fleta, C.; Rodríguez, J.; Quirion, D.; Pellegrini, G.; Lousa, A.; Martínez-de-Olcoz, L.; Pombar, M.; Lozano, M.

    2013-05-01

    The accurate detection and dosimetry of neutrons in mixed and pulsed radiation fields is a demanding instrumental issue with great interest both for the industrial and medical communities. In recent studies of neutron contamination around medical linacs, there is a growing concern about the secondary cancer risk for radiotherapy patients undergoing treatment in photon modalities at energies greater than 6 MV. In this work we present a promising alternative to standard detectors with an active method to measure neutrons around a medical linac using a novel ultra-thin silicon detector with 3D electrodes adapted for neutron detection. The active volume of this planar device is only 10 µm thick, allowing a high gamma rejection, which is necessary to discriminate the neutron signal in the radiotherapy peripheral radiation field with a high gamma background. Different tests have been performed in a clinical facility using a Siemens PRIMUS linac at 6 and 15 MV. The results show a good thermal neutron detection efficiency around 2% and a high gamma rejection factor.

  17. The Relationship Between Local Recurrence and Radiotherapy Treatment Volume for Soft Tissue Sarcomas Treated With External Beam Radiotherapy and Function Preservation Surgery

    SciTech Connect

    Dickie, Colleen I.; Griffin, Anthony M.; Parent, Amy L.; Chung, Peter W.M.; Catton, Charles N.; Svensson, Jon; Ferguson, Peter C.; Wunder, Jay S.; Bell, Robert S.; Sharpe, Michael B.; O'Sullivan, Brian

    2012-03-15

    Purpose: To examine the geometric relationship between local recurrence (LR) and external beam radiotherapy (RT) volumes for soft-tissue sarcoma (STS) patients treated with function-preserving surgery and RT. Methods and Materials: Sixty of 768 (7.8%) STS patients treated with combined therapy within our institution from 1990 through 2006 developed an LR. Thirty-two received preoperative RT, 16 postoperative RT, and 12 preoperative RT plus a postoperative boost. Treatment records, RT simulation images, and diagnostic MRI/CT data sets of the original and LR disease were retrospectively compared. For LR location analysis, three RT target volumes were defined according to the International Commission on Radiation Units and Measurements 29 as follows: (1) the gross tumor or operative bed; (2) the treatment volume (TV) extending 5 cm longitudinally beyond the tumor or operative bed unless protected by intact barriers to spread and at least 1-2 cm axially (the TV was enclosed by the isodose curve representing the prescribed target absorbed dose [TAD] and accounted for target/patient setup uncertainty and beam characteristics), and (3) the irradiated volume (IRV) that received at least 50% of the TAD, including the TV. LRs were categorized as developing in field within the TV, marginal (on the edge of the IRV), and out of field (occurring outside of the IRV). Results: Forty-nine tumors relapsed in field (6.4% overall). Nine were out of field (1.1% overall), and 2 were marginal (0.3% overall). Conclusions: The majority of STS tumors recur in field, indicating that the incidence of LR may be affected more by differences in biologic and molecular characteristics rather than aberrations in RT dose or target volume coverage. In contrast, only two patients relapsed at the IRV boundary, suggesting that the risk of a marginal relapse is low when the TV is appropriately defined. These data support the accurate delivery of optimal RT volumes in the most precise way using advanced

  18. MO-H-19A-01: FEATURED PRESENTATION - Treatment Planning Tool for Radiotherapy with Very High-Energy Electron Beams

    SciTech Connect

    Bazalova, M; Qu, B; Palma, B; Loo, B; Maxim, P; Hynning, E; Hardemark, B

    2014-06-15

    Purpose: To develop a tool for treatment planning optimization for fast radiotherapy delivered with very high-energy electron beams (VHEE) and to compare VHEE plans to state-of-the-art plans for challenging pelvis and H'N cases. Methods: Treatment planning for radiotherapy delivered with VHEE scanning pencil beams was performed by integrating EGSnrc Monte Carlo (MC) dose calculations with spot scanning optimization run in a research version of RayStation. A Matlab GUI for MC beamlet generation was developed, in which treatment parameters such as the pencil beam size and spacing, energy and number of beams can be selected. Treatment planning study for H'N and pelvis cases was performed and the effect of treatment parameters on the delivered dose distributions was evaluated and compared to the clinical treatment plans. The pelvis case with a 691cm3 PTV was treated with 2-arc 15MV VMAT and the H'N case with four PTVs with total volume of 531cm3 was treated with 4-arc 6MV VMAT. Results: Most studied VHEE plans outperformed VMAT plans. The best pelvis 80MeV VHEE plan with 25 beams resulted in 12% body dose sparing and 8% sparing to the bowel and right femur compared to the VMAT plan. The 100MeV plan was superior to the 150MeV plan. Mixing 100 and 150MeV improved dose sparing to the bladder by 7% compared to either plan. Plans with 16 and 36 beams did not significantly affect the dose distributions compared to 25 beam plans. The best H'N 100MeV VHEE plan decreased mean doses to the brainstem, chiasm, and both globes by 10-42% compared to the VMAT plan. Conclusion: The pelvis and H'N cases suggested that sixteen 100MeV beams might be sufficient specifications of a novel VHEE treatment machine. However, optimum machine parameters will be determined with the presented VHEE treatment-planning tool for a large number of clinical cases. BW Loo and P Maxim received research support from RaySearch Laboratories. E Hynning and B Hardemark are employees of RaySearch Laboratories.

  19. Daily targeting of liver tumors: Screening patients with a mock treatment and using a combination of internal and external fiducials for image-guided respiratory-gated radiotherapy

    SciTech Connect

    Krishnan, Sunil; Briere, Tina Marie; Dong Lei; Murthy, Ravi; Ng, Chaan; Balter, Peter; Mohan, Radhe; Gillin, Michael T.; Beddar, A. Sam

    2007-12-15

    The feasibility and accuracy of using a mock treatment to screen suitable patients for respiratory-gated image-guided radiotherapy was investigated. Radio-opaque fiducials implanted adjacent to the liver tumor were used for online positioning to minimize the systematic error in patient positioning. The consistency in the degree of correlation between the external and internal fiducials was analyzed during a mock treatment. This technique could screen patients for gated therapy, reduce setup inaccuracy, and possibly individualize treatment margins.

  20. System and process for biomass treatment

    SciTech Connect

    Dunson, Jr., James B; Tucker, III, Melvin P; Elander, Richard T; Lyons, Robert C

    2013-08-20

    A system including an apparatus is presented for treatment of biomass that allows successful biomass treatment at a high solids dry weight of biomass in the biomass mixture. The design of the system provides extensive distribution of a reactant by spreading the reactant over the biomass as the reactant is introduced through an injection lance, while the biomass is rotated using baffles. The apparatus system to provide extensive assimilation of the reactant into biomass using baffles to lift and drop the biomass, as well as attrition media which fall onto the biomass, to enhance the treatment process.

  1. IMRT dose delivery effects in radiotherapy treatment planning using Monte Carlo methods

    NASA Astrophysics Data System (ADS)

    Tyagi, Neelam

    Inter- and intra-leaf transmission and head scatter can play significant roles in Intensity Modulated Radiation Therapy (IMRT)-based treatment deliveries. In order to accurately calculate the dose in the IMRT planning process, it is therefore important that the detailed geometry of the multi-leaf collimator (MLC), in addition to other components in the accelerator treatment head be accurately modeled. In this thesis Monte Carlo (MC) methods have been used to model the treatment head of a Varian linear accelerator. A comprehensive model of the Varian 120-leaf MLC has been developed within the DPM MC code and has been verified against measurements in homogeneous and heterogeneous phantom geometries under different IMRT delivery circumstances. Accuracy of the MLC model in simulating details in the leaf geometry has been established over a range of arbitrarily shaped fields and IMRT fields. A sensitivity analysis of the effect of the electron-on-target parameters and the structure of the flattening filter on the accuracy of calculated dose distributions has been conducted. Adjustment of the electron-on-target parameters resulting in optimal agreement with measurements was an iterative process, with the final parameters representing a tradeoff between small (3x3 cm2) and large (40x40 cm2) field sizes. A novel method based on adaptive kernel density estimation, in the phase space simulation process is also presented as an alternative to particle recycling. Using this model dosimetric differences between MLC-based static (SMLC) and dynamic (DMLC) deliveries have been investigated. Differences between SMLC and DMLC, possibly related to fluence and/or spectral changes, appear to vary systematically with the density of the medium. The effect of fluence modulation due to leaf sequencing shows differences, up to 10% between plans developed with 1% and 10% fluence intervals for both SMLC and DMLC-delivered sequences. Dose differences between planned and delivered leaf sequences

  2. A method for generating large datasets of organ geometries for radiotherapy treatment planning studies

    PubMed Central

    Hu, Nan; Cerviño, Laura; Segars, Paul; Lewis, John; Shan, Jinlu; Jiang, Steve; Zheng, Xiaolin; Wang, Ge

    2014-01-01

    Background With the rapidly increasing application of adaptive radiotherapy, large datasets of organ geometries based on the patient’s anatomy are desired to support clinical application or research work, such as image segmentation, re-planning, and organ deformation analysis. Sometimes only limited datasets are available in clinical practice. In this study, we propose a new method to generate large datasets of organ geometries to be utilized in adaptive radiotherapy. Methods Given a training dataset of organ shapes derived from daily cone-beam CT, we align them into a common coordinate frame and select one of the training surfaces as reference surface. A statistical shape model of organs was constructed, based on the establishment of point correspondence between surfaces and non-uniform rational B-spline (NURBS) representation. A principal component analysis is performed on the sampled surface points to capture the major variation modes of each organ. Results A set of principal components and their respective coefficients, which represent organ surface deformation, were obtained, and a statistical analysis of the coefficients was performed. New sets of statistically equivalent coefficients can be constructed and assigned to the principal components, resulting in a larger geometry dataset for the patient’s organs. Conclusions These generated organ geometries are realistic and statistically representative. PMID:25435856

  3. Outcome of treatment by tumorectory and radiotherapy of patients with operable breast cancer

    SciTech Connect

    Vilcoq, J.R.; Calle, R.; Stacey, P.; Ghossein, N.A.

    1981-10-01

    We performed a retrospective study on 314 patients treated for a localized breast cancer by tumorectomy and radiotherapy to determine the overall survival, incidence of loco-regional failure and outcome of salvage surgery. All patients were followed for at least three years. Two hundred and fourteen patients had tumors less than or equal to 3 cm and 74 had tumors less than or equal to 6 cm. The three and five years absolute survival, free of disease (NED), is 88% (276/314) and 84% (190/225). The incidence of loco-regional failures was not dependent on tumor size and did not exceed 10% for the entire group. Recurrences were common (35%) in young patients (less than or equal to30). No patient older than 50 had recurrences. Eighty-one percent of failures appeared within three years. Salvage surgery was performed on 78% (14/18) of patients with recurrences; 57% (8/14) were free of disease (NED). Local failure in this group was not necessarily associated with disseminated cancer. Tumorectomy followed by radiotherapy is an acceptable alternative to mastectomy, particularly since salvage surgery can usually be successfully performed for recurrences.

  4. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs

    NASA Astrophysics Data System (ADS)

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Jiang Graves, Yan; Gautier, Quentin; Mell, Loren; Zhou, Linghong; Jia, Xun; Jiang, Steve

    2013-12-01

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using

  5. Automatic treatment plan re-optimization for adaptive radiotherapy guided with the initial plan DVHs.

    PubMed

    Li, Nan; Zarepisheh, Masoud; Uribe-Sanchez, Andres; Moore, Kevin; Tian, Zhen; Zhen, Xin; Graves, Yan Jiang; Gautier, Quentin; Mell, Loren; Zhou, Linghong; Jia, Xun; Jiang, Steve

    2013-12-21

    Adaptive radiation therapy (ART) can reduce normal tissue toxicity and/or improve tumor control through treatment adaptations based on the current patient anatomy. Developing an efficient and effective re-planning algorithm is an important step toward the clinical realization of ART. For the re-planning process, manual trial-and-error approach to fine-tune planning parameters is time-consuming and is usually considered unpractical, especially for online ART. It is desirable to automate this step to yield a plan of acceptable quality with minimal interventions. In ART, prior information in the original plan is available, such as dose-volume histogram (DVH), which can be employed to facilitate the automatic re-planning process. The goal of this work is to develop an automatic re-planning algorithm to generate a plan with similar, or possibly better, DVH curves compared with the clinically delivered original plan. Specifically, our algorithm iterates the following two loops. An inner loop is the traditional fluence map optimization, in which we optimize a quadratic objective function penalizing the deviation of the dose received by each voxel from its prescribed or threshold dose with a set of fixed voxel weighting factors. In outer loop, the voxel weighting factors in the objective function are adjusted according to the deviation of the current DVH curves from those in the original plan. The process is repeated until the DVH curves are acceptable or maximum iteration step is reached. The whole algorithm is implemented on GPU for high efficiency. The feasibility of our algorithm has been demonstrated with three head-and-neck cancer IMRT cases, each having an initial planning CT scan and another treatment CT scan acquired in the middle of treatment course. Compared with the DVH curves in the original plan, the DVH curves in the resulting plan using our algorithm with 30 iterations are better for almost all structures. The re-optimization process takes about 30 s using

  6. TREATMENT OF AMMONIA PLANT PROCESS CONDENSATE EFFLUENT

    EPA Science Inventory

    The report gives results of an examination of contaminant content and selected treatment techniques for process condensate from seven different ammonia plants. Field tests were performed and data collected on an in-plant steam stripping column with vapor injection into the reform...

  7. Treatment planning for radiotherapy with very high-energy electron beams and comparison of VHEE and VMAT plans

    SciTech Connect

    Bazalova-Carter, Magdalena; Qu, Bradley; Palma, Bianey; Jensen, Christopher; Maxim, Peter G. E-mail: BWLoo@Stanford.edu; Loo, Billy W. E-mail: BWLoo@Stanford.edu; Hårdemark, Björn; Hynning, Elin

    2015-05-15

    Purpose: The aim of this work was to develop a treatment planning workflow for rapid radiotherapy delivered with very high-energy electron (VHEE) scanning pencil beams of 60–120 MeV and to study VHEE plans as a function of VHEE treatment parameters. Additionally, VHEE plans were compared to clinical state-of-the-art volumetric modulated arc therapy (VMAT) photon plans for three cases. Methods: VHEE radiotherapy treatment planning was performed by linking EGSnrc Monte Carlo (MC) dose calculations with inverse treatment planning in a research version of RayStation. In order to study the effect of VHEE treatment parameters on VHEE dose distributions, a MATLAB graphical user interface (GUI) for calculation of VHEE MC pencil beam doses was developed. Through the GUI, pediatric case MC simulations were run for a number of beam energies (60, 80, 100, and 120 MeV), number of beams (13, 17, and 36), pencil beam spot (0.1, 1.0, and 3.0 mm) and grid (2.0, 2.5, and 3.5 mm) sizes, and source-to-axis distance, SAD (40 and 50 cm). VHEE plans for the pediatric case calculated with the different treatment parameters were optimized and compared. Furthermore, 100 MeV VHEE plans for the pediatric case, a lung, and a prostate case were calculated and compared to the clinically delivered VMAT plans. All plans were normalized such that the 100% isodose line covered 95% of the target volume. Results: VHEE beam energy had the largest effect on the quality of dose distributions of the pediatric case. For the same target dose, the mean doses to organs at risk (OARs) decreased by 5%–16% when planned with 100 MeV compared to 60 MeV, but there was no further improvement in the 120 MeV plan. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams, but to a more modest degree (<8%). While pencil beam spacing and SAD had a small effect on VHEE dose distributions, 0.1–3 mm pencil beam sizes resulted in identical dose distributions. For the 100 MeV VHEE pediatric

  8. Effect of Intensity-Modulated Pelvic Radiotherapy on Second Cancer Risk in the Postoperative Treatment of Endometrial and Cervical Cancer

    SciTech Connect

    Zwahlen, Daniel R. Ruben, Jeremy D.; Jones, Phillip; Gagliardi, Frank; Millar, Jeremy L.; Schneider, Uwe

    2009-06-01

    Purpose: To estimate and compare intensity-modulated radiotherapy (IMRT) with three-dimensional conformal radiotherapy (3DCRT) in terms of second cancer risk (SCR) for postoperative treatment of endometrial and cervical cancer. Methods and Materials: To estimate SCR, the organ equivalent dose concept with a linear-exponential, a plateau, and a linear dose-response model was applied to dose distributions, calculated in a planning computed tomography scan of a 68-year-old woman. Three plans were computed: four-field 18-MV 3DCRT and nine-field IMRT with 6- and 18-MV photons. SCR was estimated as a function of target dose (50.4 Gy/28 fractions) in organs of interest according to the International Commission on Radiological Protection Results: Cumulative SCR relative to 3DCRT was +6% (3% for a plateau model, -4% for a linear model) for 6-MV IMRT and +26% (25%, 4%) for the 18-MV IMRT plan. For an organ within the primary beam, SCR was +12% (0%, -12%) for 6-MV and +5% (-2%, -7%) for 18-MV IMRT. 18-MV IMRT increased SCR 6-7 times for organs away from the primary beam relative to 3DCRT and 6-MV IMRT. Skin SCR increased by 22-37% for 6-MV and 50-69% for 18-MV IMRT inasmuch as a larger volume of skin was exposed. Conclusion: Cancer risk after IMRT for cervical and endometrial cancer is dependent on treatment energy. 6-MV pelvic IMRT represents a safe alternative with respect to SCR relative to 3DCRT, independently of the dose-response model. 18-MV IMRT produces second neutrons that modestly increase the SCR.

  9. Treatment of primary glioblastoma multiforme with cetuximab, radiotherapy and temozolomide (GERT) – phase I/II trial: study protocol

    PubMed Central

    Combs, Stephanie E; Heeger, Steffen; Haselmann, Renate; Edler, Lutz; Debus, Jürgen; Schulz-Ertner, Daniela

    2006-01-01

    Background The implementation of combined radiochemotherapy (RCHT) with temozolomide (TMZ) has lead to a significant increase in overall survival times in patients with Glioblastoma multiforme (GBM), however, outcome still remains unsatisfactory. The majority of GBMs show an overexpression and/or amplification of the epidermal growth factor receptor (EGFR). Therefore, addition of EGFR-inhibition with cetuximab to the current standard treatment approach with radiotherapy and TMZ seems promising. Methods/design GERT is a one-armed single-center phase I/II trial. In a first step, dose-escalation of TMZ from 50 mg/m2 to 75 mg/m2 together with radiotherapy and cetuximab will be performed. Should safety be proven, the phase II trial will be initiated with the standard dose of 75 mg/m2 of TMZ. Cetuximab will be applied in the standard application dose of 400 mg/m2 in week 1, thereafter at a dose of 250 mg/m2 weekly. A total of 46 patients will be included into this phase I/II trial. Primary endpoints are feasibility and toxicity, secondary endpoints are overall and progression-free survival. An interim analysis will be performed after inclusion of 15 patients into the main study. Patients' enrolment will be performed over a period of 2 years. The observation time will end 2 years after inclusion of the last patient. Discussion The goal of this study is to evaluate the safety and efficacy of combined RCHT-immunotherapy with TMZ and cetuximab as first-line treatment for patients with primary GBM. PMID:16709245

  10. Effects of postoperative adjuvant chemotherapy and radiotherapy on ovarian function in women undergoing treatment for soft tissue sarcoma

    SciTech Connect

    Shamberger, R.C.; Sherins, R.J.; Ziegler, J.L.; Glatstein, E.; Rosenberg, S.A.

    1981-12-01

    Ovarian function was evaluated in 11 women 16 to 43 years of age at treatment who received doxorubicin, cyclophosphamide, and high doses of methotrexate with or without radiotherapy in adjuvant therapy of soft tissue sarcoma. Five women (16-33 yr old) who received chemotherapy alone or combined with radiotherapy only at sites distant from the ovaries (chest wall, thigh, and leg) had minimal menstrual irregularities or temporary cessation of menses during therapy; cyclic menses returned promptly after therapy. Gonadotropin levels (expressed as means +/- SD) (follicle-stimulating hormone (FSH), 10 +/- 15 mlU/ml; luteinizing hormone (LH), 10 +/- 4 mlU/ml) and 17 ..beta..-estradiol (E/sub 2/) levels (means +/- SD, 208 +/- 147 pg/ml) were normal. By contrast, 4 older women (ages 36-43 yr) who received similar treatment developd persistent amenorrhea with postmenopausal levels of gonadotropin (FSH, 109 +/- 29 mlU/ml; LH, 72 +/- 19 mlU/ml) and E/sub 2/ (19 +/- 8 pg/ml). Two additional women (ages 21 and 39 yr) who received radiation (7000 rad) to the pelvis plus chemotherapy developed prompt cessation of menses and became functional castrates (FSH, 77 and 80mlU/ml; LH, 40 and 58 mlU/ml; E/sub 2/, 10 and 19 pg/ml). However, this result would be expected from the radiation dose alone. The data demonstrated that ovarian dysfunction may follow the use of doxorubicin, cyclophosphamide, and high doses of methotrexate and that the injury is age related.

  11. Long-Term Outcomes With Intraoperative Radiotherapy as a Component of Treatment for Locally Advanced or Recurrent Uterine Sarcoma

    SciTech Connect

    Barney, Brandon M.; Petersen, Ivy A.; Dowdy, Sean C.; Bakkum-Gamez, Jamie N.; Haddock, Michael G.

    2012-05-01

    Purpose: To report our institutional experience with intraoperative radiotherapy (IORT) as a component of treatment for women with locally advanced or recurrent uterine sarcoma. Methods and Materials: From 1990 to 2010, 16 women with primary (n = 3) or locoregionally recurrent (n = 13) uterine sarcoma received IORT as a component of combined modality treatment. Tumor histology studies found leiomyosarcoma (n = 9), endometrial stromal sarcoma (n = 4), and carcinosarcoma (n = 3). Surgery consisted of gross total resection in 2 patients, subtotal resection in 6 patients, and resection with close surgical margins in 8 patients. The median IORT dose was 12.5 Gy (range, 10-20 Gy). All patients received perioperative external beam radiotherapy (EBRT; median dose, 50.4 Gy; range, 20-62.5 Gy), and 6 patients also received perioperative systemic therapy. Results: Seven of the 16 patients are alive at a median follow-up of 44 months (range, 11-203 months). The 3-year Kaplan-Meier estimate of local relapse (within the EBRT field) was 7%, and central control (within the IORT field) was 100%. No local failures occurred in any of the 6 patients who underwent subtotal resection. The 3-year freedom from distant relapse was 48%, with failures occurring most frequently in the lungs or mediastinum. Median survival was 18 months, and 3-year Kaplan-Meier estimates of cause-specific and overall survival were 58% and 53%, respectively. Three patients (19%) experienced late Grade 3 toxicity. Conclusions: A combined modality approach with perioperative EBRT, surgery, and IORT for locally advanced or recurrent uterine sarcoma resulted in excellent local disease control with acceptable toxicity, even in patients with positive resection margins. With this approach, some patients were able to experience long-term freedom from recurrence.

  12. Commissioning and quality assurance of the Pinnacle(3) radiotherapy treatment planning system for external beam photons.

    PubMed

    Bedford, J L; Childs, P J; Nordmark Hansen, V; Mosleh-Shirazi, M A; Verhaegen, F; Warrington, A P

    2003-03-01

    The commissioning of a Pinnacle(3) treatment planning system is described. Four Elekta linear accelerators were commissioned for external beam photons. Measured data were used to derive parameter values for the Pinnacle(3) beam model by (1). fitting a Monte Carlo model of the accelerator head to measured data and then extracting the parameters for the Pinnacle(3) beam model, and by (2). using the auto-modelling facility within Pinnacle(3). Both of these methods yielded dose distributions in accord with published recommendations. A separate small-field beam model, customized for an in-house compact blocking system, was also created, which satisfied appropriate acceptance criteria for stereotactically guided conformal brain treatments. Inhomogeneous, oblique, asymmetrical and irregular fields were also assessed, with calculated and measured doses agreeing to within +/-3%. Dose-volume histogram calculation was found to be accurate to within +/-5% dose or volume for a grid size of 4 mm x 4 mm x 4 mm, with better accuracy being achieved for finer grids. Isocentric doses were compared between Pinnacle(3)'s collapsed cone convolution algorithm and the Bentley-Milan algorithm within the Target-2 treatment planning system. Dose differences were generally less than 3% in the dose prescribed, with larger values for breast plans, where the Pinnacle(3) algorithm calculated scatter more accurately. Pelvic and thoracic plans were also verified using an anthropomorphic phantom, with local dose differences between calculated and delivered dose of up to 8%, but mainly less than 3%, and with no systematic difference. Ionization chamber verifications using START and RT-01 trial procedures demonstrated differences between calculated and measured doses of less than 2%. Following satisfactory performance in the commissioning process, Pinnacle(3) has now been introduced into routine clinical use. PMID:12684232

  13. Anterior-posterior treatment localization in pelvic radiotherapy: tattoos or fixed couch-to-isocentre distance.

    PubMed

    Greer, P B; Mortensen, T M

    1997-01-01

    The methods of determining the anterior-posterior isocentre location in pelvic radiotherapy are either by aligning lateral localization lasers to tattoo marks on skin, or by setting a constant daily couch-to-isocentre distance. While using the former method the day-to-day vertical couch movement was recorded and combined with measurements of day-to-day anterior-posterior patient movement made with an electronic portal imaging device to determine whether couch vertical movement contributes to anterior-posterior setup variation. Seven unimmobilized patients were studied, four supine prostate and three prone rectum patients. The two motions were found to be highly correlated (correlation coefficient = 0.82) which supports the constant couch-to-isocentre distance approach. When the day-to-day couch vertical movement was subtracted from the anterior-posterior movement results the setup variation was reduced in six of the seven patients. PMID:9136107

  14. Energy autonomy in the wastewater treatment process

    SciTech Connect

    Bernard, J.; DaVia, P.

    1980-03-01

    Wastewater treatment plants can recover a high percentage of their energy needs by using new techniques in anaerobic digestion through the production and utilization of methane gas. The Acheres Wastewater Treatment Plant outside Paris has a present design capacity of 1.5 x 10/sup 6/ m/sup 3//d (400 mgd) and produces over 70% of its energy needs using this process. Methane gas is used to drive a series of engines that produce compressed air for the biological process and drive generators that produce electricity for use in all phases of the treatment process, equipment, and buildings. Water that cools these engines is also used to maintain optimum sludge temperature during the digestion process. After World War II, a master plan was developed that projects the plant's expansion through five major phases to an ultimate design capacity of 2.7 x 10/sup 6/ m/sup 3//d (715 mgd). To date three phases are in operation, with a total design capacity of 1.5 x 10/sup 6/ m/sup 3//d (400 mgd). Phase IV (6.0 x 10/sup 5/ m/sup 3//d, 160 mgd) is under construction. The article reviews the sludge digestion process used in all three operating phases of the plant.

  15. Deformable image registration for geometrical evaluation of DIBH radiotherapy treatment of lung cancer patients

    NASA Astrophysics Data System (ADS)

    Ottosson, W.; Lykkegaard Andersen, J. A.; Borrisova, S.; Mellemgaard, A.; Behrens, C. F.

    2014-03-01

    Respiration and anatomical variation during radiotherapy (RT) of lung cancer yield dosimetric uncertainties of the delivered dose, possibly affecting the clinical outcome if not corrected for. Adaptive radiotherapy (ART), based on deformable image registration (DIR) and Deep-Inspiration-Breath-Hold (DIBH) gating can potentially improve the accuracy of RT. Purpose: The objective was to investigate the performance of contour propagation on repeated CT and Cone Beam CT (CBCT) images in DIBH compared to images acquired in free breathing (FB), using a recently released DIR software. Method: Three locally advanced non-small cell lung cancer patients were included, each with a planning-, midterm- and final CT (pCT, mCT, fCT) and 7 CBCTs acquired weekly and on the same day as the mCT and fCT. All imaging were performed in both FB and DIBH, using Varian RPM system for respiratory tracking. Delineations of anatomical structures were performed on each image set. The CT images were retrospective rigidly and deformable registered to all obtained images using the Varian Smart Adapt v. 11.0. The registered images were analysed for volume change and Dice Similarity Coefficient (DSC). Result: Geometrical similarities were found between propagated and manually delineated structures, with a slightly favour of FB imaging. Special notice should be taken to registrations where image artefacts or low tissue contrast are present. Conclusion: This study does not support the hypothesis that DIBH images perform better image registration than FB images. However DIR is a feasible tool for ART of lung cancer.

  16. Postoperative External Beam Radiotherapy for Differentiated Thyroid Cancer: Outcomes and Morbidity With Conformal Treatment

    SciTech Connect

    Schwartz, David L. Lobo, Mark J.; Ang, K. Kian; Morrison, William H.; Rosenthal, David I.; Ahamad, Anesa; Evans, Douglas B.; Clayman, Gary; Sherman, Steven I.; Garden, Adam S.

    2009-07-15

    Purpose: To review institutional outcomes for patients treated for differentiated thyroid cancer with postoperative conformal external beam radiotherapy (EBRT). Methods and Materials: This is a single-institution retrospective review of 131 consecutive patients with differentiated thyroid cancer who underwent EBRT between January 1996 and December 2005. Histologic diagnoses included 104 papillary, 21 follicular, and six mixed papillary-follicular types. American Joint Committee on Cancer stage distribution was Stage III in 2 patients, Stage IVa-IVc in 128, and not assessable in 1. Thirty-four patients (26%) had high-risk histologic types and 76 (58%) had recurrent disease. Extraglandular disease spread was seen in 126 patients (96%), microscopically positive surgical margins were seen in 62 patients (47%), and gross residual disease was seen in 15 patients (11%). Median EBRT dose was 60 Gy (range, 38-72 Gy). Fifty-seven patients (44%) were treated with intensity-modulated radiotherapy (IMRT) to a median dose of 60 Gy (range, 56-66 Gy). Median follow-up was 38 months (range, 0-134 months). Results: Kaplan-Meier estimates of locoregional relapse-free survival, disease-specific survival, and overall survival at 4 years were 79%, 76%, and 73%, respectively. On multivariate analysis, high-risk histologic features and gross residual disease predicted for inferior locoregional relapse-free survival, whereas high-risk histologic features, M1 disease, and gross residual disease predicted for inferior disease-specific and overall survival. The IMRT did not impact on survival outcomes, but was associated with less frequent severe late morbidity (12% vs. 2%). Conclusions: Postoperative conformal EBRT provides durable locoregional disease control for patients with high-risk differentiated thyroid cancer if disease is reduced to microscopic burden. Patients with gross disease face significantly worse outcomes. The IMRT may significantly reduce chronic radiation morbidity, but

  17. [Implementation of the nursing process in a radiotherapy unit: development of a medical record].

    PubMed

    Vaz, Ana Francisca; Macedo, Denise Diniz; Montagnoli, Edina Tavares de Lima; Lopes, Maria Helena; Grion, Regina Célia

    2002-01-01

    The goal of our service is to systematize the nursing care provided to the clients with gynecological and mammary cancer who underwent radiation therapy, using the nursing process, the North American Nursing Diagnosis Association (NANDA) taxonomy and collaborative problems in the diagnoses phase. Therefore, we created a record card in which we briefly reported the relevant data to nursing care, containing: anamnesis, general explanations about treatment, main collaborative problems, nursing diagnoses, interventions, outcomes and evolution. This card was tested in service and evaluated by the group that had created it regarding content and design, enabling the elaboration of its last version that is presented in the article. PMID:12817384

  18. Comparison of Monte Carlo collimator transport methods for photon treatment planning in radiotherapy

    SciTech Connect

    Schmidhalter, D.; Manser, P.; Frei, D.; Volken, W.; Fix, M. K.

    2010-02-15

    Purpose: The aim of this work was a Monte Carlo (MC) based investigation of the impact of different radiation transport methods in collimators of a linear accelerator on photon beam characteristics, dose distributions, and efficiency. Thereby it is investigated if it is possible to use different simplifications in the radiation transport for some clinical situations in order to save calculation time. Methods: Within the Swiss Monte Carlo Plan, a GUI-based framework for photon MC treatment planning, different MC methods are available for the radiation transport through the collimators [secondary jaws and multileaf collimator (MLC)]: EGSnrc (reference), VMC++, and Pin (an in-house developed MC code). Additional nonfull transport methods were implemented in order to provide different complexity levels for the MC simulation: Considering collimator attenuation only, considering Compton scatter only or just the firstCompton process, and considering the collimators as totally absorbing. Furthermore, either a simple or an exact geometry of the collimators can be selected for the absorbing or attenuation method. Phasespaces directly above and dose distributions in a water phantom are analyzed for academic and clinical treatment fields using 6 and 15 MV beams, including intensity modulated radiation therapy with dynamic MLC. Results: For all MC transport methods, differences in the radial mean energy and radial energy fluence are within 1% inside the geometric field. Below the collimators, the energy fluence is underestimated for nonfull MC transport methods ranging from 5% for Compton to 100% for Absorbing. Gamma analysis using EGSnrc calculated doses as reference shows that the percentage of voxels fulfilling a 1% /1 mm criterion is at least 98% when using VMC++, Compton, or firstCompton transport methods. When using the methods Pin, Transmission, Flat-Transmission, Flat-Absorbing or Absorbing, the mean value of points fulfilling this criterion over all tested cases is 97

  19. Peripheral dose in ocular treatments with CyberKnife and Gamma Knife radiosurgery compared to proton radiotherapy.

    PubMed

    Zytkovicz, A; Daftari, I; Phillips, T L; Chuang, C F; Verhey, L; Petti, P L

    2007-10-01

    Peripheral radiation can have deleterious effects on normal tissues throughout the body, including secondary cancer induction and cataractogenesis. The aim of this study is to evaluate the peripheral dose received by various regions of the body after ocular treatment delivered with the Model C Gamma Knife, proton radiotherapy with a dedicated ocular beam employing no passive-scattering system, or a CyberKnife unit before and after supplemental shielding was introduced. TLDs were used for stray gamma and x-ray dosimetry, whereas CR-39 dosimeters were used to measure neutron contamination in the proton experiments. Doses to the contralateral eye, neck, thorax and abdomen were measured on our anthropomorphic phantom for a 56 Gy treatment to a 588 mm(3) posterior ocular lesion. Gamma Knife (without collimator blocking) delivered the highest dose in the contralateral eye, with 402-2380 mSv, as compared with 118-234 mSv for CyberKnife pre-shielding, 46-255 mSv for CyberKnife post-shielding and 9-12 mSv for proton radiotherapy. Gamma Knife and post-shielding CyberKnife delivered comparable doses proximal to the treatment site, with 190 versus 196 mSv at the thyroid, whereas protons doses at these locations were less than 10 mSv. Gamma Knife doses decreased dramatically with distance from the treatment site, delivering only 13 mSv at the lower pelvis, comparable to the proton result of 4 to 7 mSv in this region. In contrast, CyberKnife delivered between 117 and 132 mSv to the lower pelvis. In conclusion, for ocular melanoma treatments, a proton beam employing no double scattering system delivers the lowest peripheral doses proximally to the contralateral eye and thyroid when compared to radiosurgery with the Model C Gamma Knife or CyberKnife. At distal locations in the pelvis, peripheral doses delivered with proton and Gamma Knife are of an order of magnitude smaller than those delivered with CyberKnife. PMID:17881812

  20. Peripheral dose in ocular treatments with CyberKnife and Gamma Knife radiosurgery compared to proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Zytkovicz, A.; Daftari, I.; Phillips, T. L.; Chuang, C. F.; Verhey, L.; Petti, P. L.

    2007-09-01

    Peripheral radiation can have deleterious effects on normal tissues throughout the body, including secondary cancer induction and cataractogenesis. The aim of this study is to evaluate the peripheral dose received by various regions of the body after ocular treatment delivered with the Model C Gamma Knife, proton radiotherapy with a dedicated ocular beam employing no passive-scattering system, or a CyberKnife unit before and after supplemental shielding was introduced. TLDs were used for stray gamma and x-ray dosimetry, whereas CR-39 dosimeters were used to measure neutron contamination in the proton experiments. Doses to the contralateral eye, neck, thorax and abdomen were measured on our anthropomorphic phantom for a 56 Gy treatment to a 588 mm3 posterior ocular lesion. Gamma Knife (without collimator blocking) delivered the highest dose in the contralateral eye, with 402-2380 mSv, as compared with 118-234 mSv for CyberKnife pre-shielding, 46-255 mSv for CyberKnife post-shielding and 9-12 mSv for proton radiotherapy. Gamma Knife and post-shielding CyberKnife delivered comparable doses proximal to the treatment site, with 190 versus 196 mSv at the thyroid, whereas protons doses at these locations were less than 10 mSv. Gamma Knife doses decreased dramatically with distance from the treatment site, delivering only 13 mSv at the lower pelvis, comparable to the proton result of 4 to 7 mSv in this region. In contrast, CyberKnife delivered between 117 and 132 mSv to the lower pelvis. In conclusion, for ocular melanoma treatments, a proton beam employing no double scattering system delivers the lowest peripheral doses proximally to the contralateral eye and thyroid when compared to radiosurgery with the Model C Gamma Knife or CyberKnife. At distal locations in the pelvis, peripheral doses delivered with proton and Gamma Knife are of an order of magnitude smaller than those delivered with CyberKnife.

  1. Influence of the treatment schedule on the physicians' decisions to refer bone metastases patients for palliative radiotherapy: a questionnaire survey of physicians in various specialties.

    PubMed

    Saito, Tetsuo; Toya, Ryo; Semba, Akiko; Matsuyama, Tomohiko; Oya, Natsuo

    2016-08-01

    We investigated whether the treatment schedule influences physicians' decisions to refer their patients for radiotherapy. We presented a questionnaire to 104 physicians in various specialties at three hospitals. It included three hypothetical patients with uncomplicated painful bone metastasis: patients with an expected life span of one year (case 1), 6 months (case 2), and 2 months (case 3). The physicians were asked whether they would refer their patients for radiotherapy when a radiation oncologist presented three different treatment schedules: a short (8 Gy/1 fraction/1 day)-, a medium (20 Gy/5 fractions/1 week)-, and a long (30 Gy/10 fractions/2 weeks) schedule. We used Cochran's Q-test to compare the percentage of physicians across the three schedules and a mixed-effect logistic model to identify predictors of the selection of only the one-day schedule. Of the 104 physicians, 68 (65%) responded. Of these, 37 (54%), 27 (40%), and 26 (38%) chose to refer patients for radiotherapy when the short-, medium-, and long schedules, respectively, were proposed in case 1 (p = 0.14). These numbers were 44 (65%), 29 (43%), and 15 (22%) for case 2 (p < 0.001), and 59 (87%), 12 (18%), and 1 (1%) for case 3 (p < 0.001). Hypothetical patient and the physicians' years of practice and perspective regarding side effects were independently predictive of the selection of only the one-day schedule. In conclusion, the treatment schedule influenced the physicians' decisions to refer patients for radiotherapy. PMID:27578911

  2. A Phase II Study of Radiotherapy and Concurrent Paclitaxel Chemotherapy in Breast-Conserving Treatment for Node-Positive Breast Cancer

    SciTech Connect

    Chen, William C.; Kim, Janice; Kim, Edward; Silverman, Paula; Overmoyer, Beth; Cooper, Brenda W.; Anthony, Sue; Shenk, Robert; Leeming, Rosemary; Hanks, Shelli H.; Lyons, Janice A.

    2012-01-01

    Purpose: Administering adjuvant chemotherapy before breast radiotherapy decreases the risk of systemic recurrence, but delays in radiotherapy could yield higher local failure. We assessed the feasibility and efficacy of placing radiotherapy earlier in the breast-conserving treatment course for lymph node-positive breast cancer. Methods and Materials: Between June 2000 and December 2004, 44 women with node-positive Stage II and III breast cancer were entered into this trial. Breast-conserving surgery and 4 cycles of doxorubicin (60 mg/m{sup 2})/cyclophosphamide (600 mg/m{sup 2}) were followed by 4 cycles of paclitaxel (175 mg/m{sup 2}) delivered every 3 weeks. Radiotherapy was concurrent with the first 2 cycles of paclitaxel. The breast received 39.6 Gy in 22 fractions with a tumor bed boost of 14 Gy in 7 fractions. Regional lymphatics were included when indicated. Functional lung volume was assessed by use of the diffusing capacity for carbon monoxide as a proxy. Breast cosmesis was evaluated with the Harvard criteria. Results: The 5-year actuarial rate of disease-free survival is 88%, and overall survival is 93%. There have been no local failures. Median follow-up is 75 months. No cases of radiation pneumonitis developed. There was no significant change in the diffusing capacity for carbon monoxide either immediately after radiotherapy (p = 0.51) or with extended follow-up (p = 0.63). Volume of irradiated breast tissue correlated with acute cosmesis, and acute Grade 3 skin toxicity developed in 2 patients. Late cosmesis was not adversely affected. Conclusions: Concurrent paclitaxel chemotherapy and radiotherapy after breast-conserving surgery shortened total treatment time, provided excellent local control, and was well tolerated.

  3. Single-arc volumetric-modulated arc therapy (sVMAT) as adjuvant treatment for gastric cancer: Dosimetric comparisons with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)

    SciTech Connect

    Wang, Xin; Li, Guangjun; Zhang, Yingjie; Bai, Sen; Xu, Feng; Wei, Yuquan; Gong, Youling

    2013-01-01

    To compare the dosimetric differences between the single-arc volumetric-modulated arc therapy (sVMAT), 3-dimensional conformal radiotherapy (3D-CRT), and intensity-modulated radiotherapy (IMRT) techniques in treatment planning for gastric cancer as adjuvant radiotherapy. Twelve patients were retrospectively analyzed. In each patient's case, the parameters were compared based on the dose-volume histogram (DVH) of the sVMAT, 3D-CRT, and IMRT plans, respectively. Three techniques showed similar target dose coverage. The maximum and mean doses of the target were significantly higher in the sVMAT plans than that in 3D-CRT plans and in the 3D-CRT/IMRT plans, respectively, but these differences were clinically acceptable. The IMRT and sVMAT plans successfully achieved better target dose conformity, reduced the V{sub 20/30}, and mean dose of the left kidney, as well as the V{sub 20/30} of the liver, compared with the 3D-CRT plans. And the sVMAT technique reduced the V{sub 20} of the liver much significantly. Although the maximum dose of the spinal cord were much higher in the IMRT and sVMAT plans, respectively (mean 36.4 vs 39.5 and 40.6 Gy), these data were still under the constraints. Not much difference was found in the analysis of the parameters of the right kidney, intestine, and heart. The IMRT and sVMAT plans achieved similar dose distribution to the target, but superior to the 3D-CRT plans, in adjuvant radiotherapy for gastric cancer. The sVMAT technique improved the dose sparings of the left kidney and liver, compared with the 3D-CRT technique, but showed few dosimetric advantages over the IMRT technique. Studies are warranted to evaluate the clinical benefits of the VMAT treatment for patients with gastric cancer after surgery in the future.

  4. Volumetric Modulated Arc Therapy for Spine Radiosurgery: Superior Treatment Planning and Delivery Compared to Static Beam Intensity Modulated Radiotherapy

    PubMed Central

    Zach, Leor; Tsvang, Lev; Alezra, Dror; Ben Ayun, Maoz

    2016-01-01

    Purpose. Spine stereotactic radiosurgery (SRS) delivers an accurate and efficient high radiation dose to vertebral metastases in 1–5 fractions. We aimed to compare volumetric modulated arc therapy (VMAT) to static beam intensity modulated radiotherapy (IMRT) for spine SRS. Methods and Materials. Ten spine lesions of previously treated SRS patients were planned retrospectively using both IMRT and VMAT with a prescribed dose of 16 Gy to 100% of the planning target volume (PTV). The plans were compared for conformity, homogeneity, treatment delivery time, and safety (spinal cord dose). Results. All evaluated parameters favored the VMAT plan over the IMRT plans. Dmin in the IMRT was significantly lower than in the VMAT plan (7.65 Gy/10.88 Gy, p < 0.001), the Dice Similarity Coefficient (DSC) was found to be significantly better for the VMAT plans compared to the IMRT plans (0.77/0.58, resp., p  value < 0.01), and an almost 50% reduction in the net treatment time was calculated for the VMAT compared to the IMRT plans (6.73 min/12.96 min, p < 0.001). Conclusions. In our report, VMAT provides better conformity, homogeneity, and safety profile. The shorter treatment time is a major advantage and not only provides convenience to the painful patient but also contributes to the precision of this high dose radiation therapy. PMID:26885513

  5. Impact of hormonal treatment duration in combination with radiotherapy for locally advanced prostate cancer: Meta-analysis of randomized trials

    PubMed Central

    2010-01-01

    Background Hormone therapy plus radiotherapy significantly decreases recurrences and mortality of patients affected by locally advanced prostate cancer. In order to determine if difference exists according to the hormonal treatment duration, a literature-based meta-analysis was performed. Methods Relative risks (RR) were derived through a random-effect model. Differences in primary (biochemical failure, BF; cancer-specific survival, CSS), and secondary outcomes (overall survival, OS; local or distant recurrence, LR/DM) were explored. Absolute differences (AD) and the number needed to treat (NNT) were calculated. Heterogeneity, a meta-regression for clinic-pathological predictors and a correlation test for surrogates were conducted. Results Five trials (3,424 patients) were included. Patient population ranged from 267 to 1,521 patients. The longer hormonal treatment significantly improves BF (with significant heterogeneity) with an absolute benefit of 10.1%, and a non significant trend in CSS. With regard to secondary end-points, the longer hormonal treatment significantly decrease both the LR and the DM with an absolute difference of 11.7% and 11.5%. Any significant difference in OS was observed. None of the three identified clinico-pathological predictors (median PSA, range 9.5-20.35, Gleason score 7-10, 27-55% patients/trial, and T3-4, 13-77% patients/trial), did significantly affect outcomes. At the meta-regression analysis a significant correlation between the overall treatment benefit in BF, CSS, OS, LR and DM, and the length of the treatment was found (p≤0.03). Conclusions Although with significant heterogeneity (reflecting different patient' risk stratifications), a longer hormonal treatment duration significantly decreases biochemical, local and distant recurrences, with a trend for longer cancer specific survival. PMID:21143897

  6. Development of a novel treatment planning test for credentialing rotational intensity-modulated radiotherapy techniques in the UK

    PubMed Central

    Ciurlionis, L; Clark, C; Venables, K

    2013-01-01

    Objective: The increasing use of tomotherapy and volumetric-modulated arc therapy in UK centres will result in more centres choosing to use this technology in a clinical trial setting. The Radiotherapy Trials Quality Assurance (RTTQA) group has developed a new procedure to integrate into the UK intensity-modulated radiotherapy (IMRT) credentialing programme to cover rotational IMRT delivery techniques. Methods: A planning test [three-dimensional treatment planning system (3DTPS)] was designed specifically for rotational IMRT techniques. The feasibility of using this test in the credentialing programme for rotational IMRT was validated by 10 experienced UK centres. The study included five centres using Varian RapidArc™ (RA) (Varian Medical Systems, Milpitas, CA), two using Elekta VMAT™ (VMAT) (Elekta Inc., Norcross, GA) and three using helical tomotherapy (HT) plans. Centres were asked to carry out their own in-house quality assurance (QA) for the plans submitted for this study. A survey was sent out to centres aiming to gather information on their experience in undertaking the exercise and their QA results. Results: All centres fulfilled the primary goal by achieving the dose constraints of the primary planning target volume and organ at risk. Seven centres (three RA, one VMAT and three HT plans) were able to fulfil the secondary goal. Among those seven centres, three centres (two RA and one VMAT plans) achieved the tertiary goal. The results of the survey indicated that the 3DTPS test is a clinically relevant and practical planning test to be used. Conclusion: A planning test for rotational therapy techniques was developed for the RTTQA IMRT credentialing programme. Advances in knowledge: This study validated the feasibility of a 3DTPS test to be used as part of a credentialing programme for rotational IMRT techniques in the UK. PMID:23385993

  7. Dose-Volume Histogram Analysis of Stereotactic Body Radiotherapy Treatment of Pancreatic Cancer: A Focus on Duodenal Dose Constraints.

    PubMed

    Goldsmith, Christy; Price, Patricia; Cross, Timothy; Loughlin, Sheila; Cowley, Ian; Plowman, Nicholas

    2016-04-01

    Pancreatic carcinoma is an aggressive disease and radiotherapy treatment delivery to the primary tumor is constrained by the anatomical close location of the duodenum, stomach, and small bowel. Duodenal dose tolerance for radiosurgery in 2-5 fractions has been largely unknown. The literature was surveyed for quantitative models of risk in 1-5 fractions and we analyzed our own patient population of 44 patients with unresectable pancreatic tumors who received 3 or 5 fractions of stereotactic body radiotherapy (SBRT) between March 2009 and March 2013. A logistic model was constructed in the dose-volume histogram (DVH) Evaluator software for the duodenal D50%, D30cc, D5cc, D1cc, and maximum point dose D0.035cc. Dose tolerance limits from the literature were overlaid onto the clinical duodenal data in the form of a DVH Risk Map, with risk levels of the published limits estimated from the model of clinical data. In 3 fractions, Kopek 2010 found a statistically significant difference in D1cc of patients with no common terminology criteria for adverse events (CTCAE) v3 grade 2 or higher duodenal complications (mean D1cc = 25.3Gy) as compared with patients with grade 2 or higher toxicity (mean D1cc = 37.4Gy). From the logistic model of our duodenal data in 3 fractions, D1cc = 25.3Gy had 4.7% risk of grade 3-4 hemorrhage or stricture and D1cc = 37.4Gy had 20% risk. The 10% risk level was D1cc = 31.4Gy and we were able to keep duodenum dose for all our patients later this level. PMID:27000512

  8. Pelvic Lymph Node Topography for Radiotherapy Treatment Planning From Ferumoxtran-10 Contrast-Enhanced Magnetic Resonance Imaging

    SciTech Connect

    Dinniwell, Robert; Chan, Philip; Czarnota, Gregory; Haider, Masoom A.; Jhaveri, Kartik; Jewett, Michael; Fyles, Anthony; Jaffray, David; Milosevic, Michael

    2009-07-01

    Purpose: To define a population-based pelvic lymph node clinical target volume (CTV) for radiotherapy treatment planning using magnetic resonance (MR) imaging and the ultrasmall superparamagnetic iron oxide lymph node contrast agent ferumoxtran-10. Methods and Materials: A total of 55 eligible patients with endometrial, cervical, prostate, or bladder cancer underwent MR imaging sessions before and after contrast administration on 2 consecutive days. Ferumoxtran-10 was administered immediately after the first scan. The three-dimensional spatial distribution of the pelvic lymph nodes was determined in relation to adjacent vessels and other musculoskeletal landmarks, from which guidelines for determining a nodal CTV in individual patients were developed. Results: On average, 30 lymph nodes (range, five to 62 nodes) were identified in each patient. The distribution of nodal distances to the closest artery or vein was observed to vary in different anatomic regions. Symmetrical three-dimensional margins of expansion around the distal para-aortic (12 mm), common iliac (10 mm), external iliac (9 mm), and internal iliac (10 mm) vessels, drawn in continuity with a 12-mm expansion anterior to the sacrum and a 22-mm expansion medial to the pelvic sidewall, were shown to encompass the majority of detectable lymph nodes in most patients. Conclusion: Use of MR lymphography with ferumoxtran-10 provides an objective description of lymph node locations for radiotherapy planning. Use of this nodal CTV model in clinical practice could ensure a high probability of encompassing the regions at risk of harboring metastatic disease while minimizing the dose to adjacent normal tissues.

  9. Treatment of oilfield wastewater by Fenton's process.

    PubMed

    Gao, Y X; Yang, M; Zhang, Y; Hu, J Y

    2004-01-01

    A combination of coagulation and Fenton's process was used for the removal of total oxygen carbon (TOC) from oilfield wastewater. Compared with aluminium sulfate, ferric coagulant had better TOC removal efficiency at the same mass dosage. In Fenton's process, the effect of H2O2 and Fe2+ dose on the removal of TOC was studied. The optimum conditions required for TOC removal were an Fe3+ concentration of 40-50 mg/L, an H2O2 dose of 50 mmol/L and an Fe2+ concentration of 1.0 mmol/L. GC-MS chromatographic analysis indicated that most of the alkyl hydrocarbons of carbon numbers < 21 were removed in the first minute of Fenton's process mainly through adsorption. Alkyl hydrocarbons and phenols were oxidized almost completely following 120 min of treatment. The pathway of newly formed intermediates in Fenton's process was proposed on the basis of the GC/MS chromatogram. PMID:15077956

  10. Dosimetric difference amongst 3 techniques: TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC)

    SciTech Connect

    Lee, Francis Kar-ho Yip, Celia Wai-yi; Cheung, Frankie Chun-hung; Leung, Alex Kwok-cheung; Chau, Ricky Ming-chun; Ngan, Roger Kai-cheong

    2014-04-01

    To investigate the dosimetric difference amongst TomoTherapy, sliding-window intensity-modulated radiotherapy (IMRT), and RapidArc radiotherapy in the treatment of late-stage nasopharyngeal carcinoma (NPC). Ten patients with late-stage (Stage III or IV) NPC treated with TomoTherapy or IMRT were selected for the study. Treatment plans with these 3 techniques were devised according to departmental protocol. Dosimetric parameters for organ at risk and treatment targets were compared between TomoTherapy and IMRT, TomoTherapy and RapidArc, and IMRT and RapidArc. Comparison amongst the techniques was done by statistical tests on the dosimetric parameters, total monitor unit (MU), and expected delivery time. All 3 techniques achieved similar target dose coverage. TomoTherapy achieved significantly lower doses in lens and mandible amongst the techniques. It also achieved significantly better dose conformity to the treatment targets. RapidArc achieved significantly lower dose to the eye and normal tissue, lower total MU, and less delivery time. The dosimetric advantages of the 3 techniques were identified in the treatment of late-stage NPC. This may serve as a guideline for selection of the proper technique for different clinical cases.

  11. Stereotactic Body Radiotherapy as Primary Treatment for Elderly Patients with Medically Inoperable Head and Neck Cancer

    PubMed Central

    Vargo, John A.; Ferris, Robert L.; Clump, David A.; Heron, Dwight E.

    2014-01-01

    Purpose: With a growing elderly population, elderly patients with head and neck cancers represent an increasing challenge with limited prospective data to guide management. The complex interplay between advanced age, associated co-morbidities, and conventional local therapies, such as surgery and external beam radiotherapy ± chemotherapy, can significantly impact elderly patients’ quality of life (QoL). Stereotactic body radiotherapy (SBRT) is a well-established curative strategy for medical-inoperable early-stage lung cancers even in elderly populations; however, there is limited data examining SBRT as primary therapy in head and neck cancer. Material/methods: Twelve patients with medically inoperable head and neck cancer treated with SBRT ± cetuximab from 2002 to 2013 were retrospectively reviewed. SBRT consisted of primarily 44 Gy in five fractions delivered on alternating days over 1–2 weeks. Concurrent cetuximab was administered at a dose of 400 mg/m2 on day −7 followed by 250 mg/m2 on day 0 and +7 in n = 3 (25%). Patient-reported quality of life (PRQoL) was prospectively recorded using the previously validated University of Washington quality of life revised (UW-QoL-R). Results: Median clinical follow-up was 6 months (range: 0.5–29 months). The 1-year actuarial local progression-free survival, distant progression-free survival, progression-free survival, and overall survival for definitively treated patients were 69, 100, 69, and 64%, respectively. One patient (8%) experienced acute grade 3 dysphagia and one patient (8%) experienced late grade 3 mucositis; there were no grade 4–5 toxicities. Prospective collection of PRQoL as assessed by UW-QoL-R was preserved across domains. Conclusion: Stereotactic body radiotherapy shows encouraging survival and relatively low toxicity in elderly patients with unresectable head and neck cancer, which may provide an aggressive potentially curative local therapy while maintaining QoL. PMID

  12. SU-E-J-265: Feasibility Study of Texture Analysis for Prognosis of Local Tumor Recurrence Within 5-Years for Pharyngeal-Laryngeal Carcinoma Patients Received Radiotherapy Treatment

    SciTech Connect

    Huang, W; Tu, S

    2015-06-15

    Purpose: Pharyngeal and laryngeal carcinomas (PLC) are among the top leading cancers in Asian populations. Typically the tumor may recur and progress in a short period of time if radiotherapy fails to deliver a successful treatment. Here we used image texture features extracted from images of computed tomography (CT) planning and conducted a retrospective study to evaluate whether texture analysis is a feasible approach to predict local tumor recurrence for PLC patients received radiotherapy treatment. Methods: CT planning images of 100 patients with PLC treated by radiotherapy at our facility between 2001 and 2010 are collected. These patients were received two separate CT scans, before and mid-course of the treatment delivery. Before the radiotherapy, a CT scanning was used for the first treatment planning. A total of 30 fractions were used in the treatment and patients were scanned with a second CT around the end of the fifteenth delivery for an adaptive treatment planning. Only patients who were treated with intensity modulated radiation therapy and RapidArc were selected. Treatment planning software of Eclipse was used. The changes of texture parameters between two CT acquisitions were computed to determine whether they were correlated to the local tumor recurrence. The following texture parameters were used in the preliminary assessment: mean, variance, standard deviation, skewness, kurtosis, energy, entropy, inverse difference moment, cluster shade, inertia, cluster prominence, gray-level co-occurrence matrix, and gray-level run-length matrix. The study was reviewed and approved by the committee of our institutional review board. Results: Our calculations suggested the following texture parameters were correlated with the local tumor recurrence: skewness, kurtosis, entropy, and inertia (p<0.0.05). Conclusion: The preliminary results were positive. However some works remain crucial to be completed, including addition of texture parameters for different image

  13. Radiotherapy of malignant melanoma

    SciTech Connect

    Cooper, J.S.

    1985-04-01

    The role of radiotherapy in the treatment of malignant melanoma is limited, and surgery generally forms the mainstay of medical practice. However, there are some circumstances in which radiotherapy should be considered the treatment of choice. Symptomatic metastatic lesions in bone or brain can effectively be palliated in a substantial proportion of instances. At the current stage of our knowledge, conventionally fractionated treatment of such lesions forms the standard against which other treatments should be measured. In contrast, metastatic lesions to skin or lymph nodes that do not overlie critical normal structures probably are better treated by high-dose-per-fraction techniques. Radiotherapy may play a definitive role in the treatment of lentigo maligna. The precise optimal energy of the beam to be used remains to be defined. Slightly more penetrating radiation appears to be required for lentigo maligna melanomas. Here, too, the optimal energy remains to be defined. The treatment of nonlentigenous melanomas primarily by radiotherapy is unproved in my opinion. Certainly, the data from the Princess Margaret Hospital is exciting, but I believe it must be corroborated by a well-designed trial before it can be accepted without question. Future directions in treatment of malignant melanoma are likely to include further trials of unconventional fractionation and the use of radiosensitizing agents in conjunction with radiotherapy. The time for dermatologists and radiation therapists to cooperate in such studies is at hand.

  14. Interactive approach to segment organs at risk in radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Dolz, Jose; Kirisli, Hortense A.; Viard, Romain; Massoptier, Laurent

    2014-03-01

    Accurate delineation of organs at risk (OAR) is required for radiation treatment planning (RTP). However, it is a very time consuming and tedious task. The use in clinic of image guided radiation therapy (IGRT) becomes more and more popular, thus increasing the need of (semi-)automatic methods for delineation of the OAR. In this work, an interactive segmentation approach to delineate OAR is proposed and validated. The method is based on the combination of watershed transformation, which groups small areas of similar intensities in homogeneous labels, and graph cuts approach, which uses these labels to create the graph. Segmentation information can be added in any view - axial, sagittal or coronal -, making the interaction with the algorithm easy and fast. Subsequently, this information is propagated within the whole volume, providing a spatially coherent result. Manual delineations made by experts of 6 OAR - lungs, kidneys, liver, spleen, heart and aorta - over a set of 9 computed tomography (CT) scans were used as reference standard to validate the proposed approach. With a maximum of 4 interactions, a Dice similarity coefficient (DSC) higher than 0.87 was obtained, which demonstrates that, with the proposed segmentation approach, only few interactions are required to achieve similar results as the ones obtained manually. The integration of this method in the RTP process may save a considerable amount of time, and reduce the annotation complexity.

  15. Treatment of Nasopharyngeal Carcinoma Using Intensity-Modulated Radiotherapy-The National Cancer Centre Singapore Experience

    SciTech Connect

    Tham, Ivan Weng-Keong; Hee, Siew Wan; Yeo, Richard Ming-Chert; Salleh, Patemah; Lee, James; Tan, Terence Wee-Kiat; Fong, Kam Weng; Chua, Eu Tiong; Wee, Joseph Tien-Seng

    2009-12-01

    Purpose: The aim of this study was to determine the efficacy and acute toxicity of our early experience with treating nasopharyngeal carcinoma (NPC) patients with intensity-modulated radiotherapy (IMRT). Methods and materials: A review was conducted on case records of 195 patients with histologically proven, nonmetastatic NPC treated with IMRT between 2002 and 2005. MRI of the head and neck was fused with CT simulation images. All plans had target volumes at three dose levels, with a prescribed dose of 70 Gy to the gross disease, in 2.0-2.12 Gy/fraction over 33-35 fractions. Cisplatin-based chemotherapy was offered to Stage III/IV patients. Results: Median patient age was 52 years, and 69% were male. Median follow-up was 36.5 months. One hundred and twenty-three patients had Stage III/IV disease (63%); 50 (26%) had T4 disease. One hundred and eighty-eight (96%) had complete response; 7 (4%) had partial response. Of the complete responders, 10 (5.3%) had local recurrence, giving a 3-year local recurrence-free survival estimate of 93.1% and a 3-year disease-free survival of 82.1%. Fifty-one patients (26%) had at least one Grade 3 toxicity. Conclusions: Results from our series are comparable to those reported by other centers. Acute toxicity is common. Local failure or persistent disease, especially in patients with bulky T4 disease, are issues that must be addressed in future trials.

  16. Could preoperative short-course radiotherapy be the treatment of choice for localized advanced rectal carcinoma?

    PubMed

    Ciria, Juan Pablo; Eguiguren, Mikel; Cafiero, Sergio; Uranga, Intza; Diaz de Cerio, Ivan; Querejeta, Arrate; Urraca, Jose Maria; Minguez, Julian; Guimon, Elena; Puertolas, Jose Ramón

    2015-01-01

    Short-course preoperative radiotherapy (RT) is widely used in northern Europe for locally advanced resectable rectal cancer, but its role in the era of advanced imaging techniques is uncertain. Here, we reviewed articles and abstracts on SCRT published from 1974 through 2013 with the goal of identifying patients who might be best suited for short-course RT. We included relevant articles comparing surgery with or without preoperative radiation published before and after the advent of total mesorectal excision. We also analyzed two randomized trials directly comparing short-course RT with conventionally fractionated chemoradiation (the Polish Colorectal Study Group and the Trans-Tasman Radiation Oncology Group) that compared short-course RT with conventional chemoradiotherapy. We conclude from our review that short-course RT can be generally applied for operable rectal cancer and produces high rates of pelvic control with acceptable toxicity; it reduces local recurrence rates but does not increase overall survival. SCRT seems to be best used for tumors considered "low risk," i.e., those that are >5 cm from the anal margin, without circumferential margin involvement, and involvement of fewer than 4 lymph nodes. Whether sequential chemotherapy can further improve outcomes remains to be seen, as does the best time for surgery (immediately or 6-8 weeks after RT). We further recommend that selection of patients for short-course RT should be based on findings from magnetic resonance imaging or transrectal ultrasonography. PMID:25535578

  17. Conformal radiotherapy in the adjuvant treatment of gastric cancer: Review of 82 cases

    SciTech Connect

    Kassam, Zahra |; Lockwood, Gina |; O'Brien, Catherine; Brierley, James |; Swallow, Carol ||; Oza, Amit |; Siu, Lillian |; Knox, Jennifer J. |; Wong, Rebecca |; Cummings, Bernard; Kim, John |; Moore, Malcolm |; Ringash, Jolie |. E-mail: jolie.ringash@rmp.uhn.on.cag

    2006-07-01

    Background: The Intergroup 0116 study showed a survival benefit with adjuvant chemoradiotherapy (CRT) for resected gastric cancer. We report our experience using conformal radiotherapy (RT). Methods and Materials: Eighty-two patients with resected gastric or gastroesophageal junction (GEJ) adenocarcinoma, Stage IB to IV (M0), were treated with 45 Gy in 25 fractions using a 5-field conformal technique. Chemotherapy was in accordance with the Intergroup 0116 study, or infusional 5-fluorouracil and cisplatin in a phase I/II trial. Results: Mean age was 56.4 years. Median follow-up was 22.8 months. Grade 3 or greater acute toxicity (National Cancer Institute Common Terminology Criteria of Adverse Events, version 3.0) was noted in 57% of patients (upper gastrointestinal tract 34%, hematologic 33%). One patient died of neutropenic sepsis. Radiation Therapy Oncology Group Grade 3 late toxicity included esophageal strictures (3 patients) and small bowel obstruction (1 patient). Full course CRT was completed by 67% of patients. Of 26 patients who relapsed, 20 died. Site of first relapse was available on 23 patients: 8 locoregional and distant, 4 locoregional alone, 11 distant alone. Overall and relapse-free survival were 69% and 54% at 3 years. Conclusion: Adjuvant CRT for gastric cancer, even with conformal RT, is associated with significant toxicity. Survival was comparable to that reported in the Intergroup 0116 study.

  18. Monochromatic minibeam radiotherapy: theoretical and experimental dosimetry for preclinical treatment plans

    NASA Astrophysics Data System (ADS)

    Deman, P.; Vautrin, M.; Stupar, V.; Barbier, E. L.; Elleaume, H.; Esteve, F.; Adam, J. F.

    2011-07-01

    Monochromatic x-ray minibeam radiotherapy is a new radiosurgery approach based on arrays of submillimetric interlaced planar x-ray beams. The aim of this study was to characterize the dose distributions obtained with this new modality when being used for preclinical trials. Monte Carlo simulations were performed in water phantoms. Percentage depth-dose curves and dose profiles were computed for single incidences and interleaved incidences of 80 keV planar x-ray minibeam (0.6 × 5 mm) arrays. Peak to valley dose ratios were also computed at various depths for an increasing number of minibeams. 3D experimental polymer gel (nPAG) dosimetry measurements were performed using MRI devices designed for small animal imaging. These very high spatial resolution (50 µm) dose maps were compared to the simulations. Preclinical minibeams dose distributions were fully characterized. Experimental dosimetry correlated well with Monte Carlo calculations (Student t-tests: p > 0.1). F98 tumor-bearing rats were also irradiated with interleaved minibeams (80 keV, prescribed dose: 25 Gy). This associated preclinical trial serves as a proof of principle of the technique. The mean survival time of irradiated glioma-bearing rats increased significantly, when compared to the untreated animals (59.6 ± 2.8 days versus 28.25 ± 0.75 days, p < 0.001).

  19. Influence of Radiotherapy Treatment Concept on the Outcome of Patients With Localized Ependymomas

    SciTech Connect

    Combs, Stephanie E. Kelter, Verena; Welzel, Thomas; Behnisch, Wolfgang; Kulozik, Andreas E.; Bischof, Marc; Hof, Holger; Debus, Juergen; Schulz-Ertner, Daniela

    2008-07-15

    Purpose: To assess the outcome of 57 patients with localized ependymomas treated with radiotherapy (RT). Methods and Materials: Fifty-seven patients with localized ependymomas were treated with RT. Histology was myxopapillary ependymoma (n = 4), ependymoma (n = 23), and anaplastic ependymoma (n = 30). In 16 patients, irradiation of the craniospinal axis (CSI) was performed with a median dose of 20 Gy. Forty-one patients were treated with local RT, with a local dose of 45 Gy to the posterior fossa, including a boost to the tumor bed of 9 Gy. In 19 patients, the tumor bed was irradiated with a median dose of 54 Gy. Results: Overall survival after primary diagnosis was 83% and 71% at 3 and 5 years. Five-year overall survival was 80% in low-grade and 79% in high-grade tumors. Survival from RT was 79% at 3 and 64% at 5 years. We could not show a significant difference in overall survival between CSI and local RT only. Freedom of local failure was 67% at 5 years in patients treated with CSI and 60% at 5 years after local RT. A rate of 83% for distant failure-free survival could be observed in the CSI group as opposed to 93% in the group receiving local RT only. Conclusion: Local RT in patients with localized tumors is equieffective to CSI. The radiation oncologist must keep in mind that patients with localized ependymomas benefit from local doses {>=}45 Gy.

  20. Impact of beam quality on megavoltage radiotherapy treatment techniques utilizing gold nanoparticles for dose enhancement

    NASA Astrophysics Data System (ADS)

    Tsiamas, Panagiotis; Liu, Bo; Cifter, Fulya; Ngwa, Wilfred F.; Berbeco, Ross I.; Kappas, Constantin; Theodorou, Kiriaki; Marcus, Karen; Makrigiorgos, Mike G.; Sajo, Erno; Zygmanski, Piotr

    2013-02-01

    This study determines the optimal clinical scenarios for gold nanoparticle dose enhancement as a function of irradiation conditions and potential biological targets using megavoltage x-ray beams. Four hundred and eighty clinical beams were studied for different potential cellular or sub-cellular targets. Beam quality was determined based on a 6 MV linac with and without a flattening filter for various delivery conditions. Dose enhancement ratios DER = DGNP/Dwater were calculated for all cases using the GEANT4 Monte Carlo code and the CEPXS/ONEDANT radiation transport deterministic code. Dose enhancement using GEANT4 agreed with CEPXS/ONEDANT. DER for unflattened beams is ∼2 times larger than for flattened beams. The maximum DER values were calculated for split-IMRT fields (∼6) and for out-of-field areas of an unflattened linac (∼17). In-field DER values, at the surface of gold nanoparticles, ranged from 2.2 to 4.2 (flattened beam) and from 3 to 4.7 (unflattened beams). For a GNP cluster with thicknesses of 10 and 100 nm, the DER ranges from 14% to 287%. DER is the greatest for split-IMRT, larger depths, out-of-field areas and/or unflattened linac. Mapping of a GNP location in tumor and normal tissue is essential for efficient and safe delivery of nanoparticle-enhanced radiotherapy.

  1. Positioning accuracy for lung stereotactic body radiotherapy patients determined by on-treatment cone-beam CT imaging.

    PubMed

    Richmond, N D; Pilling, K E; Peedell, C; Shakespeare, D; Walker, C P

    2012-06-01

    Stereotactic body radiotherapy for early stage non-small cell lung cancer is an emerging treatment option in the UK. Since relatively few high-dose ablative fractions are delivered to a small target volume, the consequences of a geometric miss are potentially severe. This paper presents the results of treatment delivery set-up data collected using Elekta Synergy (Elekta, Crawley, UK) cone-beam CT imaging for 17 patients immobilised using the Bodyfix system (Medical Intelligence, Schwabmuenchen, Germany). Images were acquired on the linear accelerator at initial patient treatment set-up, following any position correction adjustments, and post-treatment. These were matched to the localisation CT scan using the Elekta XVI software. In total, 71 fractions were analysed for patient set-up errors. The mean vector error at initial set-up was calculated as 5.3 ± 2.7 mm, which was significantly reduced to 1.4 ± 0.7 mm following image guided correction. Post-treatment the corresponding value was 2.1 ± 1.2 mm. The use of the Bodyfix abdominal compression plate on 5 patients to reduce the range of tumour excursion during respiration produced mean longitudinal set-up corrections of -4.4 ± 4.5 mm compared with -0.7 ± 2.6 mm without compression for the remaining 12 patients. The use of abdominal compression led to a greater variation in set-up errors and a shift in the mean value. PMID:22665927

  2. Process for treatment of residual gas

    SciTech Connect

    Nolden, K.

    1980-01-01

    A process is disclosed for the treatment of the residual gases which are produced when hydrogen sulfide is reduced, by combustion, to elementary sulfur by the Claus process. The residual gases are fed through a heated conduit and gas scrubber, wherein the temperature of those residual gases are maintained above the melting point of sulfur. A portion of the raw coke oven gas condensate is admitted to the gas scrubber to be returned to the coke oven battery main from the flushing liquid separator as flushing liquor. The residual gases are then conducted through the coke oven gas purification process equipment along with the raw coke oven gas where the residual gases are intermixed with the raw coke oven gas prior to tar separation.

  3. Prognostic Value of Subclassification Using MRI in the T4 Classification Nasopharyngeal Carcinoma Intensity-Modulated Radiotherapy Treatment

    SciTech Connect

    Chen Lei; Liu Lizhi; Chen Mo; Li Wenfei; Yin Wenjing; Lin Aihua; Sun Ying; Li Li; Ma Jun

    2012-09-01

    Purpose: To subclassify patients with the T4 classification nasopharyngeal carcinoma (NPC), according to the seventh edition of the American Joint Committee on Cancer staging system, using magnetic resonance imaging (MRI), and to evaluate the prognostic value of subclassification after intensity-modulated radiotherapy (IMRT). Methods and Materials: A total of 140 patients who underwent MRI and were subsequently histologically diagnosed with nondisseminated classification T4 NPC received IMRT as their primary treatment and were included in this retrospective study. T4 patients were subclassified into two grades: T4a was defined as a primary nasopharyngeal tumor with involvement of the masticator space only; and T4b was defined as involvement of the intracranial region, cranial nerves, and/or orbit. Results: The 5-year overall survival (OS) rate and distant metastasis-free survival (DMFS) rate for T4a patients (82.5% and 87.0%, respectively), were significantly higher than for T4b patients (62.6% and 66.8%; p = 0.033 and p = 0.036, respectively). The T4a/b subclassification was an independent prognostic factor for OS (hazard ratio = 2.331, p = 0.032) and DMFS (hazard ratio = 2.602, p = 0.034), and had no significant effect on local relapse-free survival. Conclusions: Subclassification of T4 patients, as T4a or T4b, using MRI according to the site of invasion, has prognostic value for the outcomes of IMRT treatment in NPC.

  4. Recommendations of the Spanish Societies of Radiation Oncology (SEOR), Nuclear Medicine & Molecular Imaging (SEMNiM), and Medical Physics (SEFM) on 18F-FDG PET-CT for radiotherapy treatment planning

    PubMed Central

    Caballero Perea, Begoña; Villegas, Antonio Cabrera; Rodríguez, José Miguel Delgado; Velloso, María José García; Vicente, Ana María García; Cabrerizo, Carlos Huerga; López, Rosa Morera; Romasanta, Luis Alberto Pérez; Beltrán, Moisés Sáez

    2012-01-01

    Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) is a valuable tool for diagnosing and staging malignant lesions. The fusion of PET and computed tomography (CT) yields images that contain both metabolic and morphological information, which, taken together, have improved the diagnostic precision of PET in oncology. The main imaging modality for planning radiotherapy treatment is CT. However, PET-CT is an emerging modality for use in planning treatments because it allows for more accurate treatment volume definition. The use of PET-CT for treatment planning is highly complex, and protocols and standards for its use are still being developed. It seems probable that PET-CT will eventually replace current CT-based planning methods, but this will require a full understanding of the relevant technical aspects of PET-CT planning. The aim of the present document is to review these technical aspects and to provide recommendations for clinical use of this imaging modality in the radiotherapy planning process. PMID:24377032

  5. Dosimetric quality, accuracy, and deliverability of modulated radiotherapy treatments for spinal metastases.

    PubMed

    Kairn, Tanya; Papworth, Daniel; Crowe, Scott B; Anderson, Jennifer; Christie, David R H

    2016-01-01

    Cancer often metastasizes to the vertebra, and such metastases can be treated successfully using simple, static posterior or opposed-pair radiation fields. However, in some cases, including when re-irradiation is required, spinal cord avoidance becomes necessary and more complex treatment plans must be used. This study evaluated 16 sample intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) treatment plans designed to treat 6 typical vertebral and paraspinal volumes using a standard prescription, with the aim of investigating the advantages and limitations of these treatment techniques and providing recommendations for their optimal use in vertebral treatments. Treatment plan quality and beam complexity metrics were evaluated using the Treatment And Dose Assessor (TADA) code. A portal-imaging-based quality assurance (QA) system was used to evaluate treatment delivery accuracy, and radiochromic film measurements were used to provide high-resolution verification of treatment plan dose accuracy, especially in the steep dose gradient regions between each vertebral target and spinal cord. All treatment modalities delivered approximately the same doses and the same levels of dose heterogeneity to each planning target volume (PTV), although the minimum PTV doses in the vertebral plans were substantially lower than the prescription, because of the requirement that the plans meet a strict constraint on the dose to the spinal cord and cord planning risk volume (PRV). All plans met required dose constraints on all organs at risk, and all measured PTV-cord dose gradients were steeper than planned. Beam complexity analysis suggested that the IMRT treatment plans were more deliverable (less complex, leading to greater QA success) than the VMAT treatment plans, although the IMRT plans also took more time to deliver. The accuracy and deliverability of VMAT treatment plans were found to be substantially increased by limiting the number of monitor

  6. Intensity-Modulated Radiotherapy in the Treatment of Oropharyngeal Cancer: Clinical Outcomes and Patterns of Failure

    SciTech Connect

    Daly, Megan E.; Le, Quynh-Thu; Maxim, Peter G.; Loo, Billy W.; Kaplan, Michael J.; Fischbein, Nancy J.; Pinto, Harlan; Chang, Daniel T.

    2010-04-15

    Purpose: To report outcomes, failures, and toxicities in patients treated with intensity-modulated radiotherapy (IMRT) for squamous cell carcinoma of the oropharynx. Methods And Materials: Between Aug 2001 and Oct 2007, 107 patients were treated with IMRT with curative intent at Stanford University. Twenty-two patients were treated postoperatively, and 85 were treated definitively. Concurrent platinum-based chemotherapy was administered to 86 patients (80%) and cetuximab to 8 patients (7%). The prescribed dose was 66 Gy at 2.2 Gy/fraction for definitively treated cases and 60 Gy at 2 Gy/fraction for postoperative cases. Median follow-up was 29 months among surviving patients (range, 4-105 months). Results: Eight patients had persistent disease or local-regional failure at a median of 6.5 months (range, 0-9.9 months). Six local failures occurred entirely within the high-risk clinical target volume (CTV) (one with simultaneous distant metastasis). One patient relapsed within the high- and intermediate-risk CTV. One patient had a recurrence at the junction between the IMRT and low-neck fields. Seven patients developed distant metastasis as the first site of failure. The 3-year local-regional control (LRC), freedom from distant metastasis, overall survival, and disease-free survival rates were 92%, 92%, 83%, and 81%, respectively. T stage (T4 vs. T1-T3) was predictive of poorer LRC (p = 0.001), overall survival (p = 0.001), and disease-free survival (p < 0.001) rates. Acute toxicity consisted of 58% grade 3 mucosal and 5% grade 3 skin reactions. Six patients (6%) developed grade >=3 late complications. Conclusions: IMRT provides excellent LRC for oropharyngeal squamous cell carcinoma. Distant metastases are a major failure pattern. No marginal failures were observed.

  7. Radiotherapy alone or combined with chemotherapy as definitive treatment for squamous cell carcinoma of the tonsil.

    PubMed

    Kennedy, William R; Herman, Michael P; Deraniyagala, Rohan L; Amdur, Robert J; Werning, John W; Dziegielewski, Peter; Kirwan, Jessica; Morris, Christopher G; Mendenhall, William M

    2016-08-01

    This study is aimed at updating our institution's experience with definitive radiotherapy (RT) for squamous cell carcinoma of the tonsil. We reviewed 531 patients treated between 1983 and 2012 with definitive RT for squamous cell carcinoma of the tonsil. Of these, 179 patients were treated with either induction (n = 19) or concomitant (n = 160) chemotherapy. Planned neck dissection was performed on 217 patients: unilaterally in 199 and bilaterally in 18 patients. Median follow-up was 5.2 years for all patients (range 0.1-31.6 years) and 8.2 years for living patients (range 1.9-31.6 years). The 5-year local control rates by T stage were as follows: T1, 94 %; T2, 87 %; T3 79 %; T4, 70 %; and overall, 83 %. Multivariate analysis revealed that local control was significantly influenced by T stage and neck dissection. The 5-year cause-specific survival rates by overall stage were as follows: I, 94 %; II, 88 %; III, 87 %; IVA, 75 %; IVB, 52 %; and overall, 78 %. Multivariate analysis revealed that cause-specific survival was significantly influenced by T stage, N stage, overall stage, fractionation, neck dissection, sex, and ethnicity. Of 77 patients treated with ipsilateral fields only, contralateral neck failure occurred in 1 %. The rate of severe complications was 12 %. Definitive RT for patients with tonsillar squamous cell carcinoma provides control rates equivalent to other modalities with a comparatively low incidence of late complications. Patients with anterior tonsillar pillar or tonsillar fossa primaries that are well lateralized with no base of tongue or soft palate extension may be treated with ipsilateral fields. PMID:27059836

  8. A Novel Active Contour Model for MRI Brain Segmentation used in Radiotherapy Treatment Planning

    PubMed Central

    Mostaar, Ahmad; Houshyari, Mohammad; Badieyan, Saeedeh

    2016-01-01

    Introduction Brain image segmentation is one of the most important clinical tools used in radiology and radiotherapy. But accurate segmentation is a very difficult task because these images mostly contain noise, inhomogeneities, and sometimes aberrations. The purpose of this study was to introduce a novel, locally statistical active contour model (ACM) for magnetic resonance image segmentation in the presence of intense inhomogeneity with the ability to determine the position of contour and energy diagram. Methods A Gaussian distribution model with different means and variances was used for inhomogeneity, and a moving window was used to map the original image into another domain in which the intensity distributions of inhomogeneous objects were still Gaussian but were better separated. The means of the Gaussian distributions in the transformed domain can be adaptively estimated by multiplying a bias field by the original signal within the window. Then, a statistical energy function is defined for each local region. Also, to evaluate the performance of our method, experiments were conducted on MR images of the brain for segment tumors or normal tissue as visualization and energy functions. Results In the proposed method, we were able to determine the size and position of the initial contour and to count iterations to have a better segmentation. The energy function for 20 to 430 iterations was calculated. The energy function was reduced by about 5 and 7% after 70 and 430 iterations, respectively. These results showed that, with increasing iterations, the energy function decreased, but it decreased faster during the early iterations, after which it decreased slowly. Also, this method enables us to stop the segmentation based on the threshold that we define for the energy equation. Conclusion An active contour model based on the energy function is a useful tool for medical image segmentation. The proposed method combined the information about neighboring pixels that

  9. Fractionated stereotactic radiotherapy plus bevacizumab after response to bevacizumab plus irinotecan as a rescue treatment for high-grade gliomas

    PubMed Central

    Conde-Moreno, Antonio José; García-Gómez, Raquel; Albert-Antequera, María; Almendros-Blanco, Piedad; De Las Peñas-Bataller, Ramón; González-Vidal, Verónica; López-Torrecilla, José Luis; Ferrer-Albiach, Carlos

    2015-01-01

    Aim To evaluate the possibility of implementing a new scheme of rescue treatment after relapse or progression of high-grade glioma (HGG) treated at the first-line with bevacizumab and irinotecan (BVZ+CPT11), evaluating the response and toxicity of associating BVZ and fractionated stereotactic radiotherapy (BVZ+FSRT). Materials and methods We retrospectively analysed data from 59 patients with relapse of HGG. Nine patients with HGG relapse after treatment using the Stupp protocol that were treated with BVZ+CPT11 for progression between July 2007 and August 2012, after which the response was assessed according to the Revised Assessment in Neuro-Oncology (RANO) criteria. BVZ was administered at a dose of 10 mg/kg and FSRT up to a prescribed dose of 30 Gy, 500 cGy per fraction, three days a week. The median follow-up was 38 months. Results The treatment was well-tolerated by all patients. The response after nuclear magnetic resonance imaging (MRI) at 3–6 months was progression in two patients, stable disease in four, and three patients had a partial response. The median overall survival (OS) from diagnosis until death or the last control was 36.8 months. The median progression-free survival (PFS) was 10.8 months. The results from tumour sub-group analysis indicated that the PFS was not statistically significant although it seemed that it was higher in grade-III. The OS was higher in grade-III gliomas. Conclusions The combination of BVZ+FSRT as a second-line HGG relapse rescue treatment is well-tolerated and seems to offer promising results. We believe that multi-centre prospective studies are needed to determine the long-term efficacy and toxicity of this therapeutic approach. PMID:25949228

  10. Synergy of Radiotherapy and a Cancer Vaccine for the Treatment of HPV-Associated Head and Neck Cancer.

    PubMed

    Mondini, Michele; Nizard, Mevyn; Tran, Thi; Mauge, Laetitia; Loi, Mauro; Clémenson, Céline; Dugue, Delphine; Maroun, Pierre; Louvet, Emilie; Adam, Julien; Badoual, Cécile; Helley, Dominique; Dransart, Estelle; Johannes, Ludger; Vozenin, Marie-Catherine; Perfettini, Jean-Luc; Tartour, Eric; Deutsch, Eric

    2015-06-01

    There is growing interest in the association of radiotherapy and immunotherapy for the treatment of solid tumors. Here, we report an extremely effective combination of local irradiation (IR) and Shiga Toxin B (STxB)-based human papillomavirus (HPV) vaccination for the treatment of HPV-associated head and neck squamous cell carcinoma (HNSCC). The efficacy of the irradiation and vaccine association was tested using a model of HNSCC obtained by grafting TC-1/luciferase cells at a submucosal site of the inner lip of immunocompetent mice. Irradiation and the STxB-E7 vaccine acted synergistically with both single and fractionated irradiation schemes, resulting in complete tumor clearance in the majority of the treated mice. A dose threshold of 7.5 Gy was required to elicit the dramatic antitumor response. The combined treatment induced high levels of tumor-infiltrating, antigen-specific CD8(+) T cells, which were required to trigger the antitumor activity. Treatment with STxB-E7 and irradiation induced CD8(+) T-cell memory, which was sufficient to exert complete antitumor responses in both local recurrences and distant metastases. We also report for the first time that a combination therapy based on local irradiation and vaccination induces an increased pericyte coverage (as shown by αSMA and NG2 staining) and ICAM-1 expression on vessels. This was associated with enhanced intratumor vascular permeability that correlated with the antitumor response, suggesting that the combination therapy could also act through an increased accessibility for immune cells. The combination strategy proposed here offers a promising approach that could potentially be transferred into early-phase clinical trials. PMID:25833837

  11. Registration of DRRs and portal images for verification of stereotactic body radiotherapy: a feasibility study in lung cancer treatment

    NASA Astrophysics Data System (ADS)

    Künzler, Thomas; Grezdo, Jozef; Bogner, Joachim; Birkfellner, Wolfgang; Georg, Dietmar

    2007-04-01

    Image guidance has become a pre-requisite for hypofractionated radiotherapy where the applied dose per fraction is increased. Particularly in stereotactic body radiotherapy (SBRT) for lung tumours, one has to account for set-up errors and intrafraction tumour motion. In our feasibility study, we compared digitally reconstructed radiographs (DRRs) of lung lesions with MV portal images (PIs) to obtain the displacement of the tumour before irradiation. The verification of the tumour position was performed by rigid intensity based registration and three different merit functions such as the sum of squared pixel intensity differences, normalized cross correlation and normalized mutual information. The registration process then provided a translation vector that defines the displacement of the target in order to align the tumour with the isocentre. To evaluate the registration algorithms, 163 test images were created and subsequently, a lung phantom containing an 8 cm3 tumour was built. In a further step, the registration process was applied on patient data, containing 38 tumours in 113 fractions. To potentially improve registration outcome, two filter types (histogram equalization and display equalization) were applied and their impact on the registration process was evaluated. Generated test images showed an increase in successful registrations when applying a histogram equalization filter whereas the lung phantom study proved the accuracy of the selected algorithms, i.e. deviations of the calculated translation vector for all test algorithms were below 1 mm. For clinical patient data, successful registrations occurred in about 59% of anterior-posterior (AP) and 46% of lateral projections, respectively. When patients with a clinical target volume smaller than 10 cm3 were excluded, successful registrations go up to 90% in AP and 50% in lateral projection. In addition, a reliable identification of the tumour position was found to be difficult for clinical target volumes

  12. Radical External Beam Radiotherapy for Clinically Localized Prostate Cancer in Japan: Changing Trends in the Patterns of Care Process Survey

    SciTech Connect

    Ogawa, Kazuhiko; Nakamura, Katsumasa; Sasaki, Tomonari; Onishi, Hiroshi; Koizumi, Masahiko; Araya, Masayuki; Mukumoto, Nobutaka; Teshima, Teruki; Mitsumori, Michihide

    2011-12-01

    Purpose: To delineate changing trends in radical external beam radiotherapy (EBRT) for prostate cancer in Japan. Methods and Materials: Data from 841 patients with clinically localized prostate cancer treated with EBRT in the Japanese Patterns of Care Study (PCS) from 1996 to 2005 were analyzed. Results: Significant increases in the proportions of patients with stage T1 to T2 disease and decrease in prostate-specific antigen values were observed. Also, there were significant increases in the percentages of patients treated with radiotherapy by their own choice. Median radiation doses were 65.0 Gy and 68.4 Gy from 1996 to 1998 and from 1999 to 2001, respectively, increasing to 70 Gy from 2003 to 2005. Moreover, conformal therapy was more frequently used from 2003 to 2005 (84.9%) than from 1996 to 1998 (49.1%) and from 1999 to 2001 (50.2%). On the other hand, the percentage of patients receiving hormone therapy from 2003 to 2005 (81.1%) was almost the same as that from 1996 to 1998 (86.3%) and from 1999 to 2001 (89.7%). Compared with the PCS in the United States, patient characteristics and patterns of treatments from 2003 to 2005 have become more similar to those in the United States than those from 1996 to 1998 and those from 1999 to 2001. Conclusions: This study indicates a trend toward increasing numbers of patients with early-stage disease and increasing proportions of patients treated with higher radiation doses with advanced equipment among Japanese prostate cancer patients treated with EBRT during 1996 to 2005 survey periods. Patterns of care for prostate cancer in Japan are becoming more similar to those in the United States.

  13. SU-E-T-608: Performance Comparison of Four Commercial Treatment Planning Systems Applied to Intensity-Modulated Radiotherapy

    SciTech Connect

    Cao, Y; Li, R; Chi, Z

    2014-06-01

    Purpose: To compare the performances of four commercial treatment planning systems (TPS) used for the intensity-modulated radiotherapy (IMRT). Methods: Ten patients of nasopharyngeal (4 cases), esophageal (3 cases) and cervical (3 cases) cancer were randomly selected from a 3-month IMRT plan pool at one radiotherapy center. For each patient, four IMRT plans were newly generated by using four commercial TPS (Corvus, Monaco, Pinnacle and Xio), and then verified with Matrixx (two-dimensional array/IBA Company) on Varian23EX accelerator. A pass rate (PR) calculated from the Gamma index by OminiPro IMRT 1.5 software was evaluated at four plan verification standards (1%/1mm, 2%/2mm, 3%/3mm, 4%/4mm and 5%/5mm) for each treatment plan. Overall and multiple pairwise comparisons of PRs were statistically conducted by analysis of covariance (ANOVA) F and LSD tests among four TPSs. Results: Overall significant (p>0.05) differences of PRs were found among four TPSs with F test values of 3.8 (p=0.02), 21.1(>0.01), 14.0 (>0.01), 8.3(>0.01) at standards of 1%/1mm to 4%/4mm respectively, except at 5%/5mm standard with 2.6 (p=0.06). All means (standard deviation) of PRs at 3%/3mm of 94.3 ± 3.3 (Corvus), 98.8 ± 0.8 (Monaco), 97.5± 1.7 (Pinnacle), 98.4 ± 1.0 (Xio) were above 90% and met clinical requirement. Multiple pairwise comparisons had not demonstrated a consistent low or high pattern on either TPS. Conclusion: Matrixx dose verification results show that the validation pass rates of Monaco and Xio plans are relatively higher than those of the other two; Pinnacle plan shows slight higher pass rate than Corvus plan; lowest pass rate was achieved by the Corvus plan among these four kinds of TPS.

  14. Assessment of treatment-induced female sexual morbidity in oncology: is this a part of routine medical follow-up after radical pelvic radiotherapy?

    PubMed Central

    White, I D; Allan, H; Faithfull, S

    2011-01-01

    Background: Oncology follow-up has traditionally prioritised disease surveillance and the assessment and management of symptoms associated with cancer and its treatment. Over the past decade, the focus on late effects of treatment has increased, particularly those that have an adverse effect on long-term function and quality of life. The aim of this research was to explore factors that influence the identification of treatment-induced female sexual difficulties in routine oncology follow-up after radical pelvic radiotherapy. Methods: A structured observation schedule was used to systematically record topics discussed in 69 radiotherapy follow-up consultations observed over a 5-month period. Results: Analysis suggests that physical toxicity assessment focused on bowel (81%) and bladder (70%) symptoms. Vaginal toxicity was discussed less frequently (42%) and sexual issues were explored in only 25% of consultations. Formal recording of radiation toxicity through assessment questionnaires was limited to patients participating in clinical trials. Surveillance activity and the management of active physical symptoms predominated and psychosocial issues were addressed in only 42% of consultations. Interpretation: Female sexual morbidity after pelvic radiotherapy remains a neglected aspect of routine follow-up and cancer survivorship. Developments in both individual practice and service provision are necessary if the identification and management of treatment-induced female sexual difficulties is to be improved. PMID:21897386

  15. Outcome Prediction in Clinical Treatment Processes.

    PubMed

    Huang, Zhengxing; Dong, Wei; Ji, Lei; Duan, Huilong

    2016-01-01

    Clinical outcome prediction, as strong implications for health service delivery of clinical treatment processes (CTPs), is important for both patients and healthcare providers. Prior studies typically use a priori knowledge, such as demographics or patient physical factors, to estimate clinical outcomes at early stages of CTPs (e.g., admission). They lack the ability to deal with temporal evolution of CTPs. In addition, most of the existing studies employ data mining or machine learning methods to generate a prediction model for a specific type of clinical outcome, however, a mathematical model that predicts multiple clinical outcomes simultaneously, has not yet been established. In this study, a hybrid approach is proposed to provide a continuous predictive monitoring service on multiple clinical outcomes. More specifically, a probabilistic topic model is applied to discover underlying treatment patterns of CTPs from electronic medical records. Then, the learned treatment patterns, as low-dimensional features of CTPs, are exploited for clinical outcome prediction across various stages of CTPs based on multi-label classification. The proposal is evaluated to predict three typical classes of clinical outcomes, i.e., length of stay, readmission time, and the type of discharge, using 3492 pieces of patients' medical records of the unstable angina CTP, extracted from a Chinese hospital. The stable model was characterized by 84.9% accuracy and 6.4% hamming-loss with 3 latent treatment patterns discovered from data, which outperforms the benchmark multi-label classification algorithms for clinical outcome prediction. Our study indicates the proposed approach can potentially improve the quality of clinical outcome prediction, and assist physicians to understand the patient conditions, treatment inventions, and clinical outcomes in an integrated view. PMID:26573645

  16. Treatment Outcomes and Prognostic Factors in Mexican Patients with Endometrial Carcinoma with Emphasis on Patients Receiving Radiotherapy after Surgery: An Institutional Perspective

    PubMed Central

    Flores, Christian; Mariscal, Carlos; Celis, Alfredo; Balcázar, Nidia M.; Meneses, Abelardo; Mohar, Alejandro; Mota, Aida; Trejo, Elizabeth

    2012-01-01

    Aim. To analyze the clinical characteristics and treatment outcomes in patients with endometrial carcinoma treated in a Latin American institute with emphasis in patients receiving adjuvant radiotherapy. Methods. A total of 412 patients with endometrial carcinoma admitted to our hospital between 1998 and 2008 were evaluated, retrospectively. The mean age was 55 years (28–87). Two hundred seventy patients received RT following surgery. Stage distribution was as follows: 221 patients (54%) stage I, 86 patients (21%) stage II, and 103 patients (24.5%) stage III and 2 patients (0.5%) stage IVA. Results. Overall survival rate was 95% at 2 years, 84% at 5 years, and 79% at 10 years. By the end of followup, 338 patients (82%) were disease-free, and 13 (3%) were alive with disease. Univariate and multivariate analyses identified age, grade, serosal and adnexial involvement as significant predictors for overall survival. Conclusion. The results of our study suggests that early-stage, low-grade endometrial cancer with no risk factors should not receive external beam radiotherapy, intermediate risk patients should receive only vaginal vault brachytherapy, and the use of chemotherapy with radiotherapy for patients high-risk and advanced-stage carcinoma the addition of radiotherapy is associated with a better survival being an effective therapeutic option. PMID:22675641

  17. Treatment complications after sequential combination chemotherapy and radiotherapy with or without surgery in previously untreated squamous cell carcinoma of the head and neck

    SciTech Connect

    Posner, M.R.; Weichselbaum, R.R.; Fitzgerald, T.J.; Clark, J.R.; Rose, C.; Fabian, R.L.; Norris, C.M. Jr.; Miller, D.; Tuttle, S.A.; Ervin, T.J.

    1985-11-01

    One hundred consecutive patients with previously untreated advanced squamous cell carcinoma of the head and neck were treated with induction combination chemotherapy followed by definitive surgery and/or radiotherapy, and were evaluated for radiotherapy related toxicity. The induction regimen consisted of cisplatin, bleomycin and methotrexate/leucovorin. Acute toxicity consisted predominantly of mucositis and weight loss, and was mild or moderate by degree in 94% of patients. Six percent of patients experienced severe or life threatening acute toxicities. Two acute toxic deaths were noted in this series, one from a combination of mucositis, weight loss and infection and one from hypoglycemia of unknown origin. Thirty-five percent of patients had radiation treatment interrupted briefly because of acute toxicity. Radiotherapy dose, surgical intervention and age did not have an impact on the presence or degree of acute toxicity. Late toxicities included: hypothyroidism in 32% of patients tested: osteoradionecrosis in 5% of patients, associated primarily with a composite resection (4 of 5 cases); and soft tissue ulcerations in 3%. Taken together, these data indicate that induction combination chemotherapy did not significantly increase the toxicity of subsequent radiotherapy with or without surgery.

  18. Radiotherapy for lung cancer

    SciTech Connect

    Bleehen, N.M.; Cox, J.D.

    1985-05-01

    The role of radiation therapy in the management of lung cancer was reviewed at a workshop held in Cambridge, England, in June 1984. It was concluded that there was a continuing role for radiation therapy in the primary management of small cell lung cancer, including the loco-regional treatment for patients with limited disease. Radical radiotherapy for patients with non-small cell carcinoma could be curative for a proportion of patients with limited disease. Careful planning and quality control was essential. Palliative radiotherapy provided useful treatment for many other patients. Other related aspects of treatment are also presented.

  19. Four-dimensional CT scans for treatment planning in stereotactic radiotherapy for stage I lung cancer

    SciTech Connect

    Underberg, Rene; Lagerwaard, Frank J. . E-mail: fj.lagerwaard@vumc.nl; Cuijpers, Johan P.; Slotman, Ben J.; van Soernsen de Koste, John R.; Senan, Suresh

    2004-11-15

    Purpose: Hypofractionated stereotactic radiotherapy (SRT) for Stage I non-small-cell lung cancer requires that meticulous attention be paid toward ensuring optimal target definition. Two computed tomography (CT) scan techniques for defining internal target volumes (ITV) were evaluated. Methods and materials: Ten consecutive patients treated with SRT underwent six 'standard' rapid multislice CT scans to generate an ITV{sub 6CT} and one four-dimensional CT (4DCT) scan that generated volumetric datasets for 10 phases of the respiratory cycle, all of which were used to generate an ITV{sub 4DCT}. Geometric and dosimetric analyses were performed for (1) PTV{sub 4DCT}, derived from the ITV{sub 4DCT} with the addition of a 3-mm margin; (2) PTV{sub 6CT}, derived from the ITV{sub 6CT} with the addition of a 3-mm margin; and (3) 6 PTV{sub 10mm}, derived from each separate GTV{sub 6CT}, to which a three-dimensional margin of 10 mm was added. Results: The ITV{sub 4DCT} was not significantly different from the ITV{sub 6CT} in 8 patients, but was considerably larger in 2 patients whose tumors exhibited the greatest mobility. On average, the ITV{sub 6CT} missed on average 22% of the volume encompassing both ITVs, in contrast to a corresponding mean value of only 8.3% for ITV{sub 4DCT}. Plans based on PTV{sub 4DCT} resulted in coverage of the PTV{sub 6CT} by the 80% isodose in all patients. However, plans based on use of PTV{sub 6CT} led to a mean PTV{sub 4DCT} coverage of only 92.5%, with a minimum of 77.7% and 77.5% for the two most mobile tumors. PTVs derived from a single multislice CT expanded with a margin of 10 mm were on average twice the size of PTVs derived using the other methods, but still led to an underdosing in the two most mobile tumors. Conclusions: Individualized ITVs can improve target definition for SRT of Stage I non-small-cell lung cancer, and use of only a single CT scan with a 10-mm margin is inappropriate. A single 4D scan generates comparable or larger

  20. Stereotactic radiotherapy for the treatment of lung cancer with a giant left atrial tumor thrombus: A case report and literature review

    PubMed Central

    LI, YONG; LOU, JINRONG; QIU, SHUJUN; GUO, YUTIAN; PAN, MIANSHUN

    2016-01-01

    Lung cancer presenting with a giant atrial tumor thrombus is particularly rare. Surgical resection, aided by a cardiopulmonary bypass, is the standard treatment of choice if there is no distant metastasis. However, this form of surgery carries a high risk, with the subsequent patient prognosis being extremely poor. The current study describes the case of a 52-year-old man presenting with left lung squamous cell carcinoma that had extended into the left atrium. The patient was treated with stereotactic radiotherapy, and regarding the atrial disease, a complete response was achieved within 12 months. The present case demonstrates that stereotactic radiotherapy may be a beneficial palliative treatment for patients with stage IV lung cancer invading the left atrium. PMID:26998153

  1. Californium-252 Brachytherapy Combined With External-Beam Radiotherapy for Cervical Cancer: Long-Term Treatment Results

    SciTech Connect

    Lei Xin; Qian Chengyuan; Qing Yi; Zhao Kewei; Yang Zhengzhou; Dai Nan; Zhong Zhaoyang; Tang Cheng; Li Zheng; Gu Xianqing; Zhou Qian; Feng Yan; Xiong Yanli; Shan Jinlu; Wang Dong

    2011-12-01

    Purpose: To observe, by retrospective analysis, the curative effects and complications due to californium-252 ({sup 252}Cf) neutron intracavitary brachytherapy (ICBT) combined with external-beam radiotherapy (EBRT) in the treatment of cervical cancer. Methods and Materials: From February 1999 to December 2007, 696 patients with cervical cancer (Stages IB to IIIB) were treated with {sup 252}Cf-ICBT in combination of EBRT. Of all, 31 patients were at Stage IB, 104 at IIA, 363 at IIB, 64 at IIIA, and 134 at IIIB. Californium-252 ICBT was delivered at 7-12 Gy per insertion per week, with a total dose of 29-45 Gy to reference point A in three to five insertions. The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction, four times per week. After 16-38 Gy of external irradiation, the center of the whole pelvic field was blocked with a 4-cm-wide lead shield, with a total external irradiation dose of 44-56 Gy. The total treatment course was 5 to 6 weeks. Results: Overall survival rate at 3 and 5 years for all patients was 76.0% and 64.9%, respectively. Disease-free 3- and 5-year survival rates of patients were 71.2% and 58.4%, respectively. Late complications included vaginal contracture and adhesion, radiation proctitis, radiation cystitis, and inflammatory bowel, which accounted for 5.8%, 7.1%, 6.2%, and 4.9%, respectively. Univariate analysis results showed significant correlation of stage, age, histopathologic grade, and lymph node status with overall survival. Cox multiple regression analysis showed that the independent variables were stage, histopathologic grade, tumor size, and lymphatic metastasis in all patients. Conclusion: Results of this series suggest that the combined use of {sup 252}Cf-ICBT with EBRT is an effective method for treatment of cervical cancer.

  2. Intensity-modulated radiotherapy following null-margin resection is associated with improved survival in the treatment of intrahepatic cholangiocarcinoma

    PubMed Central

    Jia, Angela Y.; Wu, Jian-Xiong; Zhao, Yu-Ting; Li, Ye-Xiong; Wang, Zhi; Rong, Wei-Qi; Wang, Li-Ming; Jin, Jing; Wang, Shu-Lian; Song, Yong-Wen; Liu, Yue-Ping; Ren, Hua; Fang, Hui; Wang, Wen-Qing; Liu, Xin-Fan; Yu, Zi-Hao

    2015-01-01

    Background The current study is the first to examine the effectiveness and toxicity of postoperative intensity-modulated radiotherapy (IMRT) in the treatment of intrahepatic cholangiocarcinoma (ICC) abutting the vasculature. Specifically, we aim to assess the role of IMRT in patients with ICC undergoing null-margin (no real resection margin) resection. Methods Thirty-eight patients with ICC adherent to major blood vessels were included in this retrospective study. Null-margin resection was performed on all patients; 14 patients were further treated with IMRT. The median radiation dose delivered was 56.8 Gy (range, 50-60 Gy). The primary endpoints were overall survival (OS) and disease-free survival (DFS). Results At a median follow-up of 24.6 months, the median OS and DFS of all patients (n=38) were 17.7 months (95% CI, 13.2-22.2) and 9.9 months (95% CI, 2.8-17.0), respectively. Median OS was 21.8 months (95% CI, 15.5-28.1) among the 14 patients in the postoperative IMRT group and 15.0 months (95% CI, 9.2-20.9) among the 24 patients in the surgery-only group (P=0.049). Median DFS was 12.5 months (95% CI, 6.8-18.2) in the postoperative IMRT group and 5.5 months (95% CI, 0.7-12.3) in the surgery-only group (P=0.081). IMRT was well-tolerated. Acute toxicity included one case of Grade 3 leukopenia; late toxicity included one case of asymptomatic duodenal ulcer discovered through endoscopy. Conclusions The study results suggest that postoperative IMRT is a safe and effective treatment option following null-margin resections of ICC. Larger prospective and randomized trials are necessary to establish postoperative IMRT as a standard practice for the treatment of ICC adherent to major hepatic vessels. PMID:25830032

  3. Thermal and epithermal neutron fluence rate gradient measurements by PADC detectors in LINAC radiotherapy treatments-field

    SciTech Connect

    Barrera, M. T. Barros, H.; Pino, F.; Sajo-Bohus, L.; Dávila, J.

    2015-07-23

    LINAC VARIAN 2100 is where energetic electrons produce Bremsstrahlung radiation, with energies above the nucleon binding energy (E≈5.5MeV). This radiation induce (γ,n) and (e,e’n) reactions mainly in the natural tungsten target material (its total photoneutron cross section is about 4000 mb in a energy range from 9-17 MeV). These reactions may occur also in other components of the system (e.g. multi leaf collimator). During radiation treatment the human body may receive an additional dose inside and outside the treated volume produced by the mentioned nuclear reactions. We measured the neutron density at the treatment table using nuclear track detectors (PADC-NTD). These covered by a boron-converter are employed, including a cadmium filter, to determine the ratio between two groups of neutron energy, i.e. thermal and epithermal. The PADC-NTD detectors were exposed to the radiation field at the iso-center during regular operation of the accelerator. Neutron are determined indirectly by the converting reaction {sup 10}B(n,α){sup 7}Li the emerging charged particle leave their kinetic energy in the PADC forming a latent nuclear track, enlarged by chemical etching (6N, NaOH, 70°C). Track density provides information on the neutron density through calibration coefficient (∼1.6 10{sup 4} neutrons /track) obtained by a californium source. We report the estimation of the thermal and epithermal neutron field and its gradient for photoneutrons produced in radiotherapy treatments with 18 MV linear accelerators. It was obsered that photoneutron production have higher rate at the iso-center.

  4. Thermal and epithermal neutron fluence rate gradient measurements by PADC detectors in LINAC radiotherapy treatments-field

    NASA Astrophysics Data System (ADS)

    Barrera, M. T.; Barros, H.; Pino, F.; Dávila, J.; Sajo-Bohus, L.

    2015-07-01

    LINAC VARIAN 2100 is where energetic electrons produce Bremsstrahlung radiation, with energies above the nucleon binding energy (E≈5.5MeV). This radiation induce (γ,n) and (e,e'n) reactions mainly in the natural tungsten target material (its total photoneutron cross section is about 4000 mb in a energy range from 9-17 MeV). These reactions may occur also in other components of the system (e.g. multi leaf collimator). During radiation treatment the human body may receive an additional dose inside and outside the treated volume produced by the mentioned nuclear reactions. We measured the neutron density at the treatment table using nuclear track detectors (PADC-NTD). These covered by a boron-converter are employed, including a cadmium filter, to determine the ratio between two groups of neutron energy, i.e. thermal and epithermal. The PADC-NTD detectors were exposed to the radiation field at the iso-center during regular operation of the accelerator. Neutron are determined indirectly by the converting reaction 10B(n,α)7Li the emerging charged particle leave their kinetic energy in the PADC forming a latent nuclear track, enlarged by chemical etching (6N, NaOH, 70°C). Track density provides information on the neutron density through calibration coefficient (˜1.6 104 neutrons /track) obtained by a californium source. We report the estimation of the thermal and epithermal neutron field and its gradient for photoneutrons produced in radiotherapy treatments with 18 MV linear accelerators. It was obsered that photoneutron production have higher rate at the iso-center.

  5. An attenuation integral digital imaging technique for the treatment portal verification of conventional and intensity-modulated radiotherapy

    SciTech Connect

    Guan Huaiqun

    2010-07-15

    Purpose: To propose an attenuation integral digital imaging (AIDI) technique for the treatment portal verification of conventional and intensity-modulated radiotherapy (IMRT). Methods: In AIDI technique, an open in air fluence image I{sub o} and a patient fluence image I were acquired under the same exposure. Then after doing the dark field correction for both the I{sub o} and I, the AIDI image was simply calculated as log(I{sub o}/I), which is the attenuation integral along the ray path from the x-ray source to a detector pixel element. Theoretical analysis for the low contrast detection and the contrast to noise ratio (CNR) of AIDI was presented and compared to those for the fluence imaging. With AIDI, the variation of x-ray fluence and the variation of individual detector pixel's response can be automatically compensated without using the flood field correction. Results: The AIDI image for a contrast detail phantom demonstrated that it can efficiently suppress the background structures such as the couch and generate better visibility for low contrast objects with megavoltage x rays. The AIDI image acquired for a Catphan 500 phantom using a 60 deg. electronic dynamic wedge field also revealed more contrast disks than the fluence imaging did. Finally, AIDI for an IMRT field of a head/neck patient successfully displayed the anatomical structures underneath the treatment portal but not shown in fluence imaging. Conclusions: For IMRT and high degree wedge beams, direct imaging using them is difficult because their photon fluence is highly nonuniform. But AIDI can be used for the treatment portal verification of these beams.

  6. External Beam Radiotherapy With Endocavitary Boost for Nasopharyngeal Cancer: Treatment Results and Late Toxicity After Extended Follow-Up

    SciTech Connect

    Schinagl, Dominic A.X.; Marres, Henri A.M.; Kappelle, Arnoud C.; Merkx, Matthias A.W.; Pop, Lucas A.M.; Verstappen, Suzan M.M.; Kaanders, Johannes H.A.M.

    2010-11-01

    Purpose: To evaluate the long-term outcome after treatment of nasopharyngeal carcinoma and assess late toxicity in a multidisciplinary clinic. Methods and Materials: A retrospective analysis of 117 patients treated for nasopharyngeal cancer in a single institute between 1985 and 2002 was performed. Fifty-one long-term survivors were evaluated for late toxicity by a multidisciplinary team comprising a radiation oncologist, otolaryngologist, neurologist, and oral and maxillofacial surgeon. Results: The 5-year local control rate for T1 to T2 and T3 to T4 tumors was 97% and 76%, respectively. Five-year disease-free survival and overall survival were 82% and 88% for Stage I to IIb disease and 46% and 52% for Stage III to IVb, respectively. Late morbidity evaluation revealed Radiation Therapy Oncology Group (RTOG) Grade III to IV toxicity in 71% of patients. A high incidence of cranial nerve palsies (47%) and mandibular osteolysis (82%) was found, although these complications had limited clinical impact. Conclusions: The multidisciplinary late morbidity clinic revealed an unexpected high incidence of cranial nerve palsies and mandibular osteolysis and overall an RTOG Grade III to IV toxicity in 71% of patients treated for nasopharyngeal cancer. External beam radiotherapy with endocavitary brachytherapy produces excellent rates of local control for T1 to T2 tumors, but the high incidence of late toxicity suggests an overtreatment.

  7. Cognitive function after radiotherapy for supratentorial low-grade glioma: A North Central Cancer Treatment Group prospective study

    SciTech Connect

    Laack, Nadia N.; Brown, Paul D. . E-mail: brown.paul@mayo.edu; Ivnik, Robert J.; Furth, Alfred F. M.S.; Ballman, Karla V.; Hammack, Julie E.; Arusell, Robert M.; Shaw, Edward G.; Buckner, Jan C.

    2005-11-15

    Purpose: To evaluate the effects of cranial radiotherapy (RT) on cognitive function in patients with supratentorial low-grade glioma. Methods and Materials: Twenty adult patients with supratentorial low-grade glioma were treated with 50.4 Gy (10 patients) or 64.8 Gy (10 patients) localized RT. The patients then were evaluated with an extensive battery of psychometric tests at baseline (before RT) and at approximately 18-month intervals for as long as 5 years after completing RT. To allow patients to serve as their own controls, cognitive performance was evaluated as change in scores over time. All patients underwent at least two evaluations. Results: Baseline test scores were below average compared with age-specific norms. At the second evaluation, the groups' mean test scores were higher than their initial performances on all psychometric measures, although the improvement was not statistically significant. No changes in cognitive performance were seen during the evaluation period when test scores were analyzed by age, treatment, tumor location, tumor type, or extent of resection. Conclusions: Cognitive function was stable after RT in these patients evaluated prospectively during 3 years of follow-up. Slight improvements in some cognitive areas are consistent with practice effects attributable to increased familiarity with test procedures and content.

  8. Definitive extended field intensity-modulated radiotherapy and concurrent cisplatin chemosensitization in the treatment of IB2-IIIB cervical cancer

    PubMed Central

    Zhang, Guangyu; He, Fangfang; Fu, Chunli; Zhang, Youzhong; Yang, Qiuan; Wang, Jianbo

    2014-01-01

    Objective To assess the toxicity of delivering extended field intensity-modulated radiotherapy (EF-IMRT) and concurrent cisplatin chemotherapy for locally advanced cervical carcinoma. Methods Forty-five patients who underwent EF-IMRT and concurrent cisplatin chemotherapy for the treatment of stage IB2 to IIIB cervical cancer were retrospectively reviewed. The clinical target volume included all areas of gross and potentially microscopic disease and regional lymph node regions. All patients underwent high-dose-rate brachytherapy. The acute and late toxicity were scored using the Common Terminology Criteria for Adverse Events and the Radiation Therapy Oncology Group late radiation morbidity scoring criteria, respectively. Results The median follow-up was 28 months (range, 5 to 62 months). Forty-two patients had a complete response, and three had a persistent disease. Of those 42 patients, 15 patients (35.7%) had recurrence. The regions of recurrence were in-field in 2 patients and out-field in 13 patients. Acute grade ≥3 gastrointestinal, genitourinary and hematologic toxicity occurred in 3, 1, and 9 patients, respectively. Three patients (6.7%) suffered from late grade 3 toxicities. Seven patients experienced ovarian transposition, 5 of those patients (71%) maintained ovarian function. Thirty-eight patients (84.4%) were alive at the last follow-up. Conclusion Concurrent cisplatin chemotherapy with EF-IMRT was safe. The acute and late toxicities are acceptable. EF-IMRT provides an opportunity to preserve endocrine function for patients with ovarian transposition. PMID:24459576

  9. Advanced Reduction Processes: A New Class of Treatment Processes

    PubMed Central

    Vellanki, Bhanu Prakash; Batchelor, Bill; Abdel-Wahab, Ahmed

    2013-01-01

    Abstract A new class of treatment processes called advanced reduction processes (ARPs) is proposed. ARPs combine activation methods and reducing agents to form highly reactive reducing radicals that degrade oxidized contaminants. Batch screening experiments were conducted to identify effective ARPs by applying several combinations of activation methods (ultraviolet light, ultrasound, electron beam, and microwaves) and reducing agents (dithionite, sulfite, ferrous iron, and sulfide) to degradation of four target contaminants (perchlorate, nitrate, perfluorooctanoic acid, and 2,4 dichlorophenol) at three pH-levels (2.4, 7.0, and 11.2). These experiments identified the combination of sulfite activated by ultraviolet light produced by a low-pressure mercury vapor lamp (UV-L) as an effective ARP. More detailed kinetic experiments were conducted with nitrate and perchlorate as target compounds, and nitrate was found to degrade more rapidly than perchlorate. Effectiveness of the UV-L/sulfite treatment process improved with increasing pH for both perchlorate and nitrate. We present the theory behind ARPs, identify potential ARPs, demonstrate their effectiveness against a wide range of contaminants, and provide basic experimental evidence in support of the fundamental hypothesis for ARP, namely, that activation methods can be applied to reductants to form reducing radicals that degrade oxidized contaminants. This article provides an introduction to ARPs along with sufficient data to identify potentially effective ARPs and the target compounds these ARPs will be most effective in destroying. Further research will provide a detailed analysis of degradation kinetics and the mechanisms of contaminant destruction in an ARP. PMID:23840160

  10. Undesirable financial effects of head and neck cancer radiotherapy during the initial treatment period

    PubMed Central

    Egestad, Helen; Nieder, Carsten

    2015-01-01

    Background Healthcare cost and reforms are at the forefront of international debates. One of the current discussion themes in oncology is whether and how patients’ life changes due to costs of cancer care. In Norway, the main part of the treatment costs is supported by general taxpayer revenues. Objectives The objective of this study was to clarify whether head and neck cancer patients (n=67) in northern Norway experienced financial health-related quality of life (HRQOL) deterioration due to costs associated with treatment. Design HRQOL was examined by the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 in the beginning and in the end of radiation treatment in patients treated at the University Hospital in Northern Norway. Changes in financial HRQOL were calculated and compared by paired sample T-tests. Multiple regression analyses were used to examine correlations among gender, marital status, age and treatment with or without additional chemotherapy and changes in the HRQOL domain of financial difficulties. Results The majority of score results at both time points were in the lower range (mean 15–25), indicating limited financial difficulties. We observed no statistically significant differences by gender, marital status and age. Increasing financial difficulties during treatment were reported by male patients and those younger than 65, that is, patients who were younger than retirement age. The largest effect was seen in singles. However, differences were not statistically significant. Conclusions During the initial phase of the disease trajectory, no significant increase in financial difficulties was found. This is in line with the aims of the Norwegian public healthcare model. However, long-term longitudinal studies should be performed, especially with regard to the trends we observed in single, male and younger patients. PMID:25623815

  11. Integral dose investigation of non-coplanar treatment beam geometries in radiotherapy

    SciTech Connect

    Nguyen, Dan; Dong, Peng; Ruan, Dan; Low, Daniel A.; Sheng, Ke; Long, Troy; Romeijn, Edwin

    2014-01-15

    Purpose: Automated planning and delivery of non-coplanar plans such as 4π radiotherapy involving a large number of fields have been developed to take advantage of the newly available automated couch and gantry on C-arm gantry linacs. However, there is an increasing concern regarding the potential changes in the integral dose that needs to be investigated. Methods: A digital torso phantom and 22 lung and liver stereotactic body radiation therapy (SBRT) patients were included in the study. The digital phantom was constructed as a water equivalent elliptical cylinder with a major axis length of 35.4 cm and minor axis of 23.6 cm. A 4.5 cm diameter target was positioned at varying depths along the major axis. Integral doses from intensity modulated, non-coplanar beams forming a conical pattern were compared against the equally spaced coplanar beam plans. Integral dose dependence on the phantom geometry and the beam number was also quantified. For the patient plans, the non-coplanar and coplanar beams and fluences were optimized using a column generation and pricing approach and compared against clinical VMAT plans using two full (lung) or partial coplanar arcs (liver) entering at the side proximal to the tumor. Both the average dose to the normal tissue volume and the total volumes receiving greater than 2 Gy (V2) and 5 Gy (V5) were evaluated and compared. Results: The ratio of integral dose from the non-coplanar and coplanar plans depended on the tumor depth for the phantom; for tumors shallower than 10 cm, the non-coplanar integral doses were lower than coplanar integral doses for non-coplanar angles less than 60°. Similar patterns were observed in the patient plans. The smallest non-coplanar integral doses were observed for tumor 6–8 cm deep. For the phantom, the integral dose was independent of the number of beams, consistent with the liver SBRT patients but the lung SBRT patients showed slight increase in the integral dose when more beams were used. Larger

  12. Dosimetric Impact of Breathing Motion in Lung Stereotactic Body Radiotherapy Treatment Using Image-Modulated Radiotherapy and Volumetric Modulated Arc Therapy

    SciTech Connect

    Rao Min; Wu Jianzhou; Cao Daliang; Wong, Tony; Mehta, Vivek; Shepard, David; Ye Jinsong

    2012-06-01

    Purpose: The objective of this study was to investigate the influence of tumor motion on dose delivery in stereotactic body radiotherapy (SBRT) for lung cancer, using fixed field intensity- modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Methods and Materials: For each of 10 patients with stage I/II non-small-cell pulmonary tumors, a respiration-correlated four-dimensional computed tomography (4DCT) study was carried out. The internal target volume was delineated on the maximum intensity projection CT, which was reconstructed from the 4DCT dataset. A 5-mm margin was used for generation of the planning target volume. VMAT and five-field IMRT plans were generated using Pinnacle{sup 3} SmartArc and direct machine parameter optimization, respectively. All plans were generated for an Elekta Synergy linear accelerator using 6-MV photons. Simulation was performed to study the interplay between multileaf collimator (MLC) sequences and target movement during the delivery of VMAT and IMRT. For each plan, 4D dose was calculated using deformable image registration of the 4DCT images. Target volume coverage and doses to critical structures calculated using 4D methodology were compared with those calculated using 3D methodology. Results: For all patients included in this study, the interplay effect was found to present limited impact (less than 1% of prescription) on the target dose distribution, especially for SBRT, in which fewer fractions (three fractions) are delivered. Dose to the gross tumor volume (GTV) was, on average, slightly decreased (1% of prescription) in the 4D calculation compared with the 3D calculation. The motion impact on target dose homogeneity was patient-dependent and relatively small. Conclusions: Both VMAT and IMRT plans experienced negligible interplay effects between MLC sequence and tumor motion. For the most part, the 3D doses to the GTV and critical structures provided good approximations of the 4D dose calculations.

  13. [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

  14. Metronomic chemotherapy and radiotherapy as salvage treatment in refractory or relapsed pediatric solid tumours

    PubMed Central

    Ali, A.M.; El-Sayed, M.I.

    2016-01-01

    Background Metronomic chemotherapy (mctx) combined with radiation therapy (rt) is an emerging anticancer strategy. The aim of the present study was to assess the efficacy of mctx combined with rt as salvage treatment in children with refractory or relapsed solid malignancies. Methods This prospective study enrolled patients with refractory or relapsed pediatric solid tumours from January 2013 to January 2015. Treatment consisted of 3–12 courses of mctx in all patients, followed by rt in patients who experienced local recurrence, distant metastases, or both. Each course of mctx consisted of oral celecoxib 100–400 mg twice daily (days 1–42), intravenous vinblastine 3 mg/m2 weekly (weeks 1–6), oral cyclophosphamide 2.5 mg/m2 daily (days 1–21), and oral methotrexate 15 mg/m2 twice weekly (days 21–42). Statistical methods used were the log-rank test and binary logistic regression. Results A favourable disease response (partial response or stable disease) was seen in 49 of 64 patients (76.6%), with mild acute toxicity occurring in 41 (64%). After a median follow-up of 14 months, 1-year overall survival was 62%. Pattern of disease relapse (p < 0.0001), time from initial treatment to relapse (p = 0.0002), and response to treatment (p < 0.0001) significantly affected survival. Age was the only factor that significantly correlated with treatment toxicity (p = 0.002; hazard ratio: 3.37; 95% confidence interval: 1.53 to 7.35) Conclusions Combining mctx with rt resulted in a favourable response rate, minimal toxicity, and 62% 1-year overall survival in patients with heavily pretreated recurrent disease. Patients with localized late recurrence or disease progression are the most likely to benefit from this regimen. PMID:27330362

  15. Clinical Application of in-room PET for in vivo Treatment Monitoring in Proton Radiotherapy

    PubMed Central

    Min, Chul Hee; Zhu, Xuping; Winey, Brian A.; Grogg, Kira; Testa, Mauro; Fakhri, Georges El; Bortfeld, Thomas R.; Paganetti, Harald; Shih, Helen A.

    2013-01-01

    Purpose/Objective(s) The purpose of this study is to evaluate the potential of using an in-room PET for treatment verification in proton therapy and to derive suitable PET scan times. Materials/Methods Nine patients undergoing passive scattering proton therapy were scanned immediately after treatment with an in-room PET scanner. The scanner was positioned next to the treatment head after treatment. The Monte Carlo (MC) method was employed to reproduce PET activities for each patient. To assess the proton beam range uncertainty we designed a novel concept where the measured PET activity surface distal to the target at the end of range was compared with MC predictions. The repositioning of patients for the PET scan took on average about 2 minutes. The PET images were reconstructed considering varying scan times to test the scan time dependency of the method. Results The measured PET images show overall good spatial correlations with MC predictions. Some discrepancies could be attributed to uncertainties in the local elemental composition and biological washout. For 8 patients treated with a single field, the average range differences between PET measurements and CT-image-based MC results were less than 5 mm (< 3 mm for 6 of 8 patients) and root-mean-square deviations (RMSD) were 4-11 mm with PET-CT image co-registration errors of about 2 mm. Our results also show that a short-length PET scan of 5 minutes can yield similar results compared to a 20 minutes PET scan. Conclusions Our first clinical trials of 9 patients using an in-room PET system demonstrated its potential for in vivo treatment monitoring in proton therapy. For a quantitative range prediction with arbitrary shape of target volume, we suggest employing the distal PET activity surface. PMID:23391817

  16. Influence of the treatment schedule on the physicians’ decisions to refer bone metastases patients for palliative radiotherapy: a questionnaire survey of physicians in various specialties

    PubMed Central

    Saito, Tetsuo; Toya, Ryo; Semba, Akiko; Matsuyama, Tomohiko; Oya, Natsuo

    2016-01-01

    ABSTRACT We investigated whether the treatment schedule influences physicians’ decisions to refer their patients for radiotherapy. We presented a questionnaire to 104 physicians in various specialties at three hospitals. It included three hypothetical patients with uncomplicated painful bone metastasis: patients with an expected life span of one year (case 1), 6 months (case 2), and 2 months (case 3). The physicians were asked whether they would refer their patients for radiotherapy when a radiation oncologist presented three different treatment schedules: a short (8 Gy/1 fraction/1 day)-, a medium (20 Gy/5 fractions/1 week)-, and a long (30 Gy/10 fractions/2 weeks) schedule. We used Cochran’s Q-test to compare the percentage of physicians across the three schedules and a mixed-effect logistic model to identify predictors of the selection of only the one-day schedule. Of the 104 physicians, 68 (65%) responded. Of these, 37 (54%), 27 (40%), and 26 (38%) chose to refer patients for radiotherapy when the short-, medium-, and long schedules, respectively, were proposed in case 1 (p = 0.14). These numbers were 44 (65%), 29 (43%), and 15 (22%) for case 2 (p < 0.001), and 59 (87%), 12 (18%), and 1 (1%) for case 3 (p < 0.001). Hypothetical patient and the physicians’ years of practice and perspective regarding side effects were independently predictive of the selection of only the one-day schedule. In conclusion, the treatment schedule influenced the physicians’ decisions to refer patients for radiotherapy. PMID:27578911

  17. Health-Related Quality of Life 2 Years After Treatment With Radical Prostatectomy, Prostate Brachytherapy, or External Beam Radiotherapy in Patients With Clinically Localized Prostate Cancer

    SciTech Connect

    Ferrer, Montserrat Suarez, Jose Francisco; Guedea, Ferran; Fernandez, Pablo; Macias, Victor; Marino, Alfonso; Hervas, Asuncion; Herruzo, Ismael; Ortiz, Maria Jose; Villavicencio, Humberto; Craven-Bratle, Jordi; Garin, Olatz; Aguilo, Ferran

    2008-10-01

    Purpose: To compare treatment impact on health-related quality of life (HRQL) in patients with localized prostate cancer, from before treatment to 2 years after the intervention. Methods and Materials: This was a longitudinal, prospective study of 614 patients with localized prostate cancer treated with radical prostatectomy (134), three-dimensional external conformal radiotherapy (205), and brachytherapy (275). The HRQL questionnaires administered before and after treatment (months 1, 3, 6, 12, and 24) were the Medical Outcomes Study 36-Item Short Form, the Functional Assessment of Cancer Therapy (General and Prostate Specific), the Expanded Prostate Cancer Index Composite (EPIC), and the American Urological Association Symptom Index. Differences between groups were tested by analysis of variance and within-group changes by univariate repeated-measures analysis of variance. Generalized estimating equations (GEE) models were constructed to assess between-group differences in HRQL at 2 years of follow-up after adjusting for clinical variables. Results: In each treatment group, HRQL initially deteriorated after treatment with subsequent partial recovery. However, some dimension scores were still significantly lower after 2 years of treatment. The GEE models showed that, compared with the brachytherapy group, radical prostatectomy patients had worse EPIC sexual summary and urinary incontinence scores (-20.4 and -14.1; p < 0.001), and external radiotherapy patients had worse EPIC bowel, sexual, and hormonal summary scores (-3.55, -5.24, and -1.94; p < 0.05). Prostatectomy patients had significantly better EPIC urinary irritation scores than brachytherapy patients (+4.16; p < 0.001). Conclusions: Relevant differences between treatment groups persisted after 2 years of follow-up. Radical prostatectomy had a considerable negative effect on sexual functioning and urinary continence. Three-dimensional conformal radiotherapy had a moderate negative impact on bowel

  18. Modeling of body tissues for Monte Carlo simulation of radiotherapy treatments planned with conventional x-ray CT systems.

    PubMed

    Kanematsu, Nobuyuki; Inaniwa, Taku; Nakao, Minoru

    2016-07-01

    In the conventional procedure for accurate Monte Carlo simulation of radiotherapy, a CT number given to each pixel of a patient image is directly converted to mass density and elemental composition using their respective functions that have been calibrated specifically for the relevant x-ray CT system. We propose an alternative approach that is a conversion in two steps: the first from CT number to density and the second from density to composition. Based on the latest compilation of standard tissues for reference adult male and female phantoms, we sorted the standard tissues into groups by mass density and defined the representative tissues by averaging the material properties per group. With these representative tissues, we formulated polyline relations between mass density and each of the following; electron density, stopping-power ratio and elemental densities. We also revised a procedure of stoichiometric calibration for CT-number conversion and demonstrated the two-step conversion method for a theoretically emulated CT system with hypothetical 80 keV photons. For the standard tissues, high correlation was generally observed between mass density and the other densities excluding those of C and O for the light spongiosa tissues between 1.0 g cm(-3) and 1.1 g cm(-3) occupying 1% of the human body mass. The polylines fitted to the dominant tissues were generally consistent with similar formulations in the literature. The two-step conversion procedure was demonstrated to be practical and will potentially facilitate Monte Carlo simulation for treatment planning and for retrospective analysis of treatment plans with little impact on the management of planning CT systems. PMID:27300449

  19. Twenty years' experience in the treatment of acoustic neuromas with fractionated radiotherapy: A review of 45 cases

    SciTech Connect

    Maire, Jean-Philippe . E-mail: jean-philippe.maire@chu-bordeaux.fr; Huchet, Aymeri; Milbeo, Yann; Darrouzet, Vincent; Causse, Nicole; Celerier, Denis; Liguoro, Dominique; Bebear, Jean-Pierre

    2006-09-01

    Purpose: To evaluate very long-term results of fractionated radiotherapy (FRT) of acoustic neuromas (AN). Methods and Materials: From January 1986 to January 2004, FRT was performed in 45 consecutive patients (46 AN). Indications were as follows: poor general condition contraindicating surgery, hearing preservation in bilateral neuromas, partial resection, nonsurgical recurrence. A 3-field to 5-field technique with static beams was used. A mean total dose of 51 Gy was given (1.80 Gy/fraction). The median tumor diameter was 31 mm (range, 11-55 mm). The median follow-up from FRT was 80 months (range, 4-227 months). Results: The particularity of our series consists of a very long-term follow-up of FRT given to selected patients. Nineteen patients died, two with progressive disease, and 17 from non-AN causes. A serviceable level of hearing was preserved in 7/9 hearing patients. No patient had facial or trigeminal neuropathy. Tumor shrinkage was observed in 27 (59%) and stable disease in 16 (35%). Tumor progression occurred in three patients, 12 to 15 months after FRT. Two additional tumors recurred after shrinkage 20 and 216 months after treatment and were operated on. Actuarial local tumor control rates at 5 and 15 years were 86%. For the patient who had a tumor recurrence at 216 months, histologic examination documented transformation to a low-grade malignant peripheral nerve sheath tumor. Conclusion: Very long-term efficacy of FRT is well documented in this series. However, our results suggest that malignant transformation can occur many years after FRT so we advocate caution when using this treatment for young patients.

  20. 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

  1. Stereotactic body radiotherapy for the treatment of medically inoperable primary renal cell carcinoma: Current evidence and future directions

    PubMed Central

    Swaminath, Anand; Chu, William

    2015-01-01

    The incidence of renal cell carcinoma (RCC) is steadily rising due to an aging population and more frequent imaging of the abdomen for other medical conditions. While surgery remains the standard of care treatment for localized disease, many patients are unfit due to their advanced age and medical comorbidities. In these patients, an active surveillance strategy or ablative therapies, including radiofrequency/microwave ablation or cryotherapy, can be offered. Such options have limitations particularly with fast growing, or larger tumors. A promising ablative therapy option to consider is stereo-tactic body radiotherapy (SBRT). SBRT refers to high dose, focally ablative radiation delivered in a short time (3–5 fractions), and is safe and effective in many other cancer sites, including lung, liver and spine. SBRT offers potential advantages in the primary kidney cancer setting due to its ablative dosing (overcoming the notion of “radio-resistance”), short treatment duration (important in an elderly population), low toxicity profile (enabling SBRT to treat larger RCCs than other ablative modalities), and non-invasiveness. To date, there is limited long-term prospective data on the outcomes of SBRT in primary RCC. However, early evidence is intriguing with respect to excellent local control and low toxicity; however, most studies vary in terms of technique and radiation dosing used. Well-designed prospective cohort studies with clearly defined and standardized techniques, dosing, follow-up, and integration of quality of life outcomes will be essential to further establish the role of SBRT in management of inoperable, localized RCC. PMID:26316914

  2. Progestin-releasing intrauterine device insertion plus palliative radiotherapy in frail, elderly uterine cancer patients unfit for radical treatment

    PubMed Central

    MACCHIA, GABRIELLA; DEODATO, FRANCESCO; CILLA, SAVINO; LEGGE, FRANCESCO; CARONE, VITO; CHIANTERA, VITO; VALENTINI, VINCENZO; MORGANTI, ALESSIO GIUSEPPE; FERRANDINA, GABRIELLA

    2016-01-01

    The present study investigated the combination of levonorgestrel-releasing intrauterine device (LNG-IUD) insertion and palliative radiotherapy (RT) as a potential approach for treating frail, elderly endometrial cancer (EC) patients considered unfit for curative oncological treatments. The inclusion criteria were an age of ≥65 years, pathological confirmation of a uterine neoplasm, a Charlson comorbidity index (CCI) value of ≥4 and the presence of vaginal bleeding. Patients underwent intrauterine insertion of an LNG-IUD, and thereafter, received a total dose of 30 Gy at 3 Gy per fraction, over 10 days. The clinical target volume (CTV) was defined as the uterus and disease-involved tissues in the pelvis plus a 1-cm margin. The planning target volume was obtained by adding a 1-cm isotropic margin to the CTV. A total of 9 patients with EC (median age, 85 years; Eastern Cooperative Oncology Group performance status ≥2, ≥88.8%; obesity, 55.5%; median CCI, 5) received an LNG-IUD plus RT. An early complete resolution of bleeding was documented in 8 patients (88.8%), while the remaining patient experienced a marked improvement. The median duration of bleeding control was 18 months, while the 2-year actuarial rate of bleeding-free survival was 53.3% (median follow-up time, 20 months; range, 9–60 months). No LNG-IUD- or severe RT-related complications were documented. Overall, a high rate of bleeding remission, durable bleeding-free survival in face of the easy intrauterine insertion of an LNG-IUD and a negligible toxicity profile of the complete treatment were documented in this study, indicating a requirement for further investigation in a larger series. PMID:27123133

  3. Modeling of body tissues for Monte Carlo simulation of radiotherapy treatments planned with conventional x-ray CT systems

    NASA Astrophysics Data System (ADS)

    Kanematsu, Nobuyuki; Inaniwa, Taku; Nakao, Minoru

    2016-07-01

    In the conventional procedure for accurate Monte Carlo simulation of radiotherapy, a CT number given to each pixel of a patient image is directly converted to mass density and elemental composition using their respective functions that have been calibrated specifically for the relevant x-ray CT system. We propose an alternative approach that is a conversion in two steps: the first from CT number to density and the second from density to composition. Based on the latest compilation of standard tissues for reference adult male and female phantoms, we sorted the standard tissues into groups by mass density and defined the representative tissues by averaging the material properties per group. With these representative tissues, we formulated polyline relations between mass density and each of the following; electron density, stopping-power ratio and elemental densities. We also revised a procedure of stoichiometric calibration for CT-number conversion and demonstrated the two-step conversion method for a theoretically emulated CT system with hypothetical 80 keV photons. For the standard tissues, high correlation was generally observed between mass density and the other densities excluding those of C and O for the light spongiosa tissues between 1.0 g cm‑3 and 1.1 g cm‑3 occupying 1% of the human body mass. The polylines fitted to the dominant tissues were generally consistent with similar formulations in the literature. The two-step conversion procedure was demonstrated to be practical and will potentially facilitate Monte Carlo simulation for treatment planning and for retrospective analysis of treatment plans with little impact on the management of planning CT systems.

  4. Treatment of nasal cavity and paranasal sinus cancer with modern radiotherapy techniques in the postoperative setting-the MSKCC experience

    SciTech Connect

    Hoppe, Bradford S.; Stegman, Lauren D.; Zelefsky, Michael J.; Rosenzweig, Kenneth E.; Wolden, Suzanne L.; Patel, Snehal G.; Shah, Jatin P.; Kraus, Dennis H.; Lee, Nancy Y. . E-mail: leen2@mskcc.org

    2007-03-01

    Purpose: To perform a retrospective analysis of patients with paranasal sinus (PNS) cancer treated with postoperative radiotherapy (RT) at Memorial Sloan-Kettering Cancer Center. Methods and Materials: Between January 1987 and July 2005, 85 patients with PNS and nasal cavity cancer underwent postoperative RT. Most patients had squamous cell carcinoma (49%; n = 42), T4 tumors (52%; n = 36), and the maxillary sinus (53%; n = 45) as the primary disease site. The median radiation dose was 63 Gy. Of the 85 patients, 76 underwent CT simulation and 53 were treated with either three-dimensional conformal RT (27%; n = 23) or intensity-modulated RT (35%; n = 30). Acute and late toxicities were scored according to the Radiation Therapy Oncology Group radiation morbidity scoring criteria. Results: With a median follow-up for surviving patients of 60 months, the 5-year estimates of local progression-free, regional progression-free, distant metastasis-free, disease-free, and overall survival rates were 62%, 87%, 82%, 55%, and 67%, respectively. On multivariate analysis, squamous cell histology and cribriform plate involvement predicted for an increased likelihood of local recurrence, and squamous cell histologic features predicted for worse overall survival. None of the patients who underwent CT simulation and were treated with modern techniques developed a Grade 3-4 late complication of the eye. Conclusion: Complete surgical resection followed by adjuvant RT is an effective and safe approach in the treatment of PNS cancer. Emerging tools, such as three-dimensional conformal treatment and, in particular, intensity-modulated RT for PNS tumors, may minimize the occurrence of late complications associated with conventional RT techniques. Local recurrence remains a significant problem.

  5. Radiotherapy plus nimotuzumab or placebo in the treatment of high grade glioma patients: results from a randomized, double blind trial

    PubMed Central

    2013-01-01

    Background The prognosis of patients bearing high grade glioma remains dismal. Epidermal Growth Factor Receptor (EGFR) is well validated as a primary contributor of glioma initiation and progression. Nimotuzumab is a humanized monoclonal antibody that recognizes the EGFR extracellular domain and reaches Central Nervous System tumors, in nonclinical and clinical setting. While it has similar activity when compared to other anti-EGFR antibodies, it does not induce skin toxicity or hypomagnesemia. Methods A randomized, double blind, multicentric clinical trial was conducted in high grade glioma patients (41 anaplastic astrocytoma and 29 glioblastoma multiforme) that received radiotherapy plus nimotuzumab or placebo. Treatment and placebo groups were well-balanced for the most important prognostic variables. Patients received 6 weekly doses of 200 mg nimotuzumab or placebo together with irradiation as induction therapy. Maintenance treatment was given for 1 year with subsequent doses administered every 3 weeks. The objectives of this study were to assess the comparative overall survival, progression free survival, response rate, immunogenicity and safety. Results The median cumulative dose was 3200 mg of nimotuzumab given over a median number of 16 doses. The combination of nimotuzumab and RT was well-tolerated. The most prevalent related adverse reactions included nausea, fever, tremors, anorexia and hepatic test alteration. No anti-idiotypic response was detected, confirming the antibody low immunogenicity. The mean and median survival time for subjects treated with nimotuzumab was 31.06 and 17.76 vs. 21.07 and 12.63 months for the control group. Conclusions In this randomized trial, nimotuzumab showed an excellent safety profile and significant survival benefit in combination with irradiation. Trial registration Cuban National Register for clinical trials (No. 1745) (http://registroclinico.sld.cu/ensayos). PMID:23782513

  6. Raw Liquid Waste Treatment System and Process

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F. (Inventor)

    1974-01-01

    A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, suspended in the sewage water is first separated from the water, in which at least organic matter remains dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material adsorbs the organic matter dissolved in the water and is thereafter supplied in a counter flow direction and combined with the incoming raw sewage to at least facilitate the separation of the non-dissolved settleable materials from the sewage water. Carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

  7. Bevacizumab and radiotherapy for the treatment of glioblastoma: brothers in arms or unholy alliance?

    PubMed Central

    Niyazi, Maximilian; Harter, Patrick N.; Hattingen, Elke; Rottler, Maya; von Baumgarten, Louisa; Proescholdt, Martin; Belka, Claus; Lauber, Kirsten; Mittelbronn, Michel

    2016-01-01

    Glioblastoma (GBM) represents the most frequent primary brain tumor in adults and carries a dismal prognosis despite aggressive, multimodal treatment regimens involving maximal resection, radiochemotherapy, and maintenance chemotherapy. Histologically, GBMs are characterized by a high degree of VEGF-mediated vascular proliferation. In consequence, new targeted anti-angiogenic therapies, such as the monoclonal anti-VEGF-A antibody bevacizumab, have proven effective in attenuating tumor (neo)angiogenesis and were shown to possess therapeutic activity in several phase II trials. However, the role of bevacizumab in the context of multimodal therapy approaches appears to be rather complex. This review will give insights into current concepts, limitations, and controversies regarding the molecular mechanisms and the clinical benefits of bevacizumab treatment in combination with radio(chemo)therapy - particularly in face of the results of recent phase III trials, which failed to demonstrate convincing improvements in overall survival (OS). PMID:26575171

  8. [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

  9. Calibration of CT Hounsfield units for radiotherapy treatment planning of patients with metallic hip prostheses: the use of the extended CT-scale

    NASA Astrophysics Data System (ADS)

    Coolens, C.; Childs, P. J.

    2003-06-01

    Heterogeneity corrections for radiotherapy dose calculations are based on the electron density of the disturbing heterogeneity. However, when CT planning a radiotherapy treatment, where metallic hip implants are present, considerable artefacts are seen in the images. Often, an additional problem arises whereby no information regarding the artificial hip's composition and geometry is available. This study investigates whether the extended CT range can be used to determine the composition (hence electron density) of artificial hips in radiotherapy patients. Two CT-calibration methods were evaluated, one based on material substitution, the other a stoichiometric calibration. We also evaluate whether the physical dimensions of metal prostheses can be accurately imaged for subsequent use in treatment planning computers. Neither calibration method successfully predicted electron densities. However, the limited range of implant-materials used in patients means that the extended CT range can still successfully distinguish between implant densities. The physical dimensions can be determined to +/-2 mm by establishing the required windowing of displays for each material. The cross-sectional area of the prosthesis and the presence of other high-density objects in a CT slice can influence the generated CT number and careful design of calibration phantoms is essential.

  10. Effects of remedies made in patient setup process on residual setup errors and margins in head and neck cancer radiotherapy based on 2D image guidance

    PubMed Central

    Kapanen, Mika; Laaksomaa, Marko; Tulijoki, Tapio; Kellokumpu-Lehtinen, Pirkko-Liisa; Hyödynmaa, Simo

    2015-01-01

    Aim Patient setup errors were aimed to be reduced in radiotherapy (RT) of head-and-neck (H&N) cancer. Some remedies in patient setup procedure were proposed for this purpose. Background RT of H&N cancer has challenges due to patient rotation and flexible anatomy. Residual position errors occurring in treatment situation and required setup margins were estimated for relevant bony landmarks after the remedies made in setup process and compared with previous results. Materials and methods The formation process for thermoplastic masks was improved. Also image matching was harmonized to the vertebrae in the middle of the target and a 5 mm threshold was introduced for immediate correction of systematic errors of the landmarks. After the remedies, residual position errors of bony landmarks were retrospectively determined from 748 orthogonal X-ray images of 40 H&N cancer patients. The landmarks were the vertebrae C1–2, C5–7, the occiput bone and the mandible. The errors include contributions from patient rotation, flexible anatomy and inter-observer variation in image matching. Setup margins (3D) were calculated with the Van Herk formula. Results Systematic residual errors of the landmarks were reduced maximally by 49.8% (p ≤ 0.05) and the margins by 3.1 mm after the remedies. With daily image guidance the setup margins of the landmarks were within 4.4 mm, but larger margins of 6.4 mm were required for the mandible. Conclusions Remarkable decrease in the residual errors of the bony landmarks and setup margins were achieved through the remedies made in the setup process. The importance of quality assurance of the setup process was demonstrated. PMID:26109917

  11. Postoperative Radiotherapy for the Treatment of Solitary Fibrous Tumor With Malignant Transformation of the Pelvic: A Rare Case Report With Literature Review.

    PubMed

    Gao, Chao; Zhang, Yong; Jing, Ming; Qu, Wei; Li, Jia; Zhao, Xiang-Rong; Yu, Yong-Hua

    2016-01-01

    Solitary fibrous tumor of the pelvic is an uncommon neoplasm with nonspecific symptoms. Reports of malignant transformation are especially rare. We report a case of solitary fibrous tumor in pelvic. A unique feature of our case compared with previously reported is that this patient relapsed with malignant transformation and had significant response to radiotherapy. The patient was initially treated with surgery, followed by postoperative dimensional conformal intensity modulated radiation therapy (dynamic MLC VRIAN 23EX Linac, inversely optimized by the Eclipse system) to provide a radical cure for residual tumor.In this case, there were no signs of recurrence after six and a half years of further follow-up, indicating that postoperation radiotherapy may be an effective treatment for SFT with malignant transformation in pelvic. PMID:26765426

  12. 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.

  13. Evaluation of the peripheral dose in stereotactic radiotherapy and radiosurgery treatments1

    PubMed Central

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

    2010-01-01

    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. PMID:20831066

  14. Investigating the Temporal Effects of Respiratory-Gated and Intensity-Modulated Radiotherapy Treatment Delivery on In Vitro Survival: An Experimental and Theoretical Study

    SciTech Connect

    Keall, Paul J. Chang, Michael; Benedict, Stanley; Thames, Howard; Vedam, S. Sastry; Lin, Peck-Sun

    2008-08-01

    Purpose: To experimentally and theoretically investigate the temporal effects of respiratory-gated and intensity-modulated radiotherapy (IMRT) treatment delivery on in vitro survival. Methods and Materials: Experiments were designed to isolate the effects of periodic irradiation (gating), partial tumor irradiation (IMRT), and extended treatment time (gating and IMRT). V79 Chinese hamster lung fibroblast cells were irradiated to 2 Gy with four delivery methods and a clonogenic assay performed. Theoretical incomplete repair model calculations were performed using the incomplete repair model. Results: Treatment times ranged from 1.67 min (conformal radiotherapy, CRT) to 15 min (gated IMRT). Survival fraction calculations ranged from 68.2% for CRT to 68.7% for gated IMRT. For the same treatment time (5 min), gated delivery alone and IMRT delivery alone both had a calculated survival fraction of 68.3%. The experimental values ranged from 65.7% {+-} 1.0% to 67.3% {+-} 1.3%, indicating no significant difference between the experimental observations and theoretical calculations. Conclusion: The theoretical results predicted that of the three temporal effects of radiation delivery caused by gating and IMRT, extended treatment time was the dominant effect. Care should be taken clinically to ensure that the use of gated IMRT does not significantly increase treatment times, by evaluating appropriate respiratory gating duty cycles and IMRT delivery complexity.

  15. A simple DVH generation technique for various radiotherapy treatment planning systems for an independent information system

    NASA Astrophysics Data System (ADS)

    Min, Byung Jun; Nam, Heerim; Jeong, Il Sun; Lee, Hyebin

    2015-07-01

    In recent years, the use of a picture archiving and communication system (PACS) for radiation therapy has become the norm in hospital environments and has been suggested for collecting and managing data using Digital Imaging and Communication in Medicine (DICOM) objects from different treatment planning systems (TPSs). However, some TPSs do not provide the ability to export the dose-volume histogram (DVH) in text or other format. In addition, plan review systems for various TPSs often allow DVH recalculations with different algorithms. These algorithms result in inevitable discrepancies between the values obtained with the recalculation and those obtained with TPS itself. The purpose of this study was to develop a simple method for generating reproducible DVH values by using the TPSs. Treatment planning information, including structures and delivered dose, was exported in the DICOM format from the Eclipse v8.9 or the Pinnacle v9.6 planning systems. The supersampling and trilinear interpolation methods were employed to calculate the DVH data from 35 treatment plans. The discrepancies between the DVHs extracted from each TPS and those extracted by using the proposed calculation method were evaluated with respect to the supersampling ratio. The volume, minimum dose, maximum dose, and mean dose were compared. The variations in DVHs from multiple TPSs were compared by using the MIM software v6.1, which is a commercially available treatment planning comparison tool. The overall comparisons of the volume, minimum dose, maximum dose, and mean dose showed that the proposed method generated relatively smaller discrepancies compared with TPS than the MIM software did compare with the TPS. As the structure volume decreased, the overall percent difference increased. The largest difference was observed in small organs such as the eye ball, eye lens, and optic nerve which had volume below 10 cc. A simple and useful technique was developed to generate a DVH with an acceptable

  16. The evolving roles and controversies of radiotherapy in the treatment of glioblastoma.

    PubMed

    Hau, Eric; Shen, Han; Clark, Catherine; Graham, Peter H; Koh, Eng-Siew; L McDonald, Kerrie

    2016-06-01

    Numerous randomised controlled trials have demonstrated the benefit of radiation therapy in patients with newly diagnosed glioblastoma and it has been the cornerstone of treatment for decades. The aims of this review are to (1) Briefly outline the historical studies which resulted in radiation being the current standard of care as used in the Stupp et al. trial (2) Discuss the evolving role of radiation therapy in the management of elderly patients (3) Review the current evidence and ongoing studies of radiation use in the recurrent/salvage setting and (4) Discuss the continuing controversies of volume delineation in the planning of radiation delivery. PMID:27350891

  17. The effect of radiotherapy in the treatment of retinoblastoma upon the developing dentition

    SciTech Connect

    Doline, S.; Needleman, H.L.; Petersen, R.A.; Cassady, J.R.

    1980-03-01

    Two patients who received supervoltage x-ray external beam irradiation for treatment of retinoblastoma by standard techniques showed interference with the root formation of the maxillary deciduous molars and abnormalities of crown and root formation of the permanent maxillary molars. Both patients showed a relative maxillary retrognathism thought to be related to radiation effects on maxillary bone growth. Simulation of lateral radiation portals with subsequent beam shaping using an appropriate block placed in the radiation beam is suggested as a means to eliminate the dental complications of radiation therapy for retinoblastoma.

  18. Radiotherapy beyond cancer: Target localization in real-time MRI and treatment planning for cardiac radiosurgery

    SciTech Connect

    Ipsen, S.; Blanck, O.; Rades, D.; Oborn, B.; Bode, F.; Liney, G.; Hunold, P.; Schweikard, A.; Keall, P. J.

    2014-12-15

    Purpose: Atrial fibrillation (AFib) is the most common cardiac arrhythmia that affects millions of patients world-wide. AFib is usually treated with minimally invasive, time consuming catheter ablation techniques. While recently noninvasive radiosurgery to the pulmonary vein antrum (PVA) in the left atrium has been proposed for AFib treatment, precise target location during treatment is challenging due to complex respiratory and cardiac motion. A MRI linear accelerator (MRI-Linac) could solve the problems of motion tracking and compensation using real-time image guidance. In this study, the authors quantified target motion ranges on cardiac magnetic resonance imaging (MRI) and analyzed the dosimetric benefits of margin reduction assuming real-time motion compensation was applied. Methods: For the imaging study, six human subjects underwent real-time cardiac MRI under free breathing. The target motion was analyzed retrospectively using a template matching algorithm. The planning study was conducted on a CT of an AFib patient with a centrally located esophagus undergoing catheter ablation, representing an ideal case for cardiac radiosurgery. The target definition was similar to the ablation lesions at the PVA created during catheter treatment. Safety margins of 0 mm (perfect tracking) to 8 mm (untracked respiratory motion) were added to the target, defining the planning target volume (PTV). For each margin, a 30 Gy single fraction IMRT plan was generated. Additionally, the influence of 1 and 3 T magnetic fields on the treatment beam delivery was simulated using Monte Carlo calculations to determine the dosimetric impact of MRI guidance for two different Linac positions. Results: Real-time cardiac MRI showed mean respiratory target motion of 10.2 mm (superior–inferior), 2.4 mm (anterior–posterior), and 2 mm (left–right). The planning study showed that increasing safety margins to encompass untracked respiratory motion leads to overlapping structures even in the

  19. Dosimetric Comparison of Three-Dimensional Conformal Proton Radiotherapy, Intensity-Modulated Proton Therapy, and Intensity-Modulated Radiotherapy for Treatment of Pediatric Craniopharyngiomas

    SciTech Connect

    Boehling, Nicholas S.; Grosshans, David R.; Bluett, Jaques B.; Palmer, Matthew T.; Song, Xiaofei; Amos, Richard A.; Sahoo, Narayan; Meyer, Jeffrey J.; Mahajan, Anita; Woo, Shiao Y.

    2012-02-01

    Purpose: Cranial irradiation in pediatric patients is associated with serious long-term adverse effects. We sought to determine whether both three-dimensional conformal proton radiotherapy (3D-PRT) and intensity-modulated proton therapy (IMPT) compared with intensity-modulated radiotherapy (IMRT) decrease integral dose to brain areas known to harbor neuronal stem cells, major blood vessels, and other normal brain structures for pediatric patients with craniopharyngiomas. Methods and Materials: IMRT, forward planned, passive scattering proton, and IMPT plans were generated and optimized for 10 pediatric patients. The dose was 50.4 Gy (or cobalt Gy equivalent) delivered in 28 fractions with the requirement for planning target volume (PTV) coverage of 95% or better. Integral dose data were calculated from differential dose-volume histograms. Results: The PTV target coverage was adequate for all modalities. IMRT and IMPT yielded the most conformal plans in comparison to 3D-PRT. Compared with IMRT, 3D-PRT and IMPT plans had a relative reduction of integral dose to the hippocampus (3D-PRT, 20.4; IMPT, 51.3%{sup Asterisk-Operator }), dentate gyrus (27.3, 75.0%{sup Asterisk-Operator }), and subventricular zone (4.5, 57.8%{sup Asterisk-Operator }). Vascular organs at risk also had reduced integral dose with the use of proton therapy (anterior cerebral arteries, 33.3{sup Asterisk-Operator }, 100.0%{sup Asterisk-Operator }; middle cerebral arteries, 25.9%{sup Asterisk-Operator }, 100%{sup Asterisk-Operator }; anterior communicating arteries, 30.8{sup Asterisk-Operator }, 41.7%{sup Asterisk-Operator }; and carotid arteries, 51.5{sup Asterisk-Operator }, 77.6{sup Asterisk-Operator }). Relative reduction of integral dose to the infratentorial brain (190.7{sup Asterisk-Operator }, 109.7%{sup Asterisk-Operator }), supratentorial brain without PTV (9.6, 26.8%{sup Asterisk-Operator }), brainstem (45.6, 22.4%{sup Asterisk-Operator }), and whole brain without PTV (19.4{sup Asterisk

  20. Best of the Radiosurgery Society® Scientific Meeting 2014: stereotactic radiosurgery/stereotactic body radiotherapy treatment of extracranial and intracranial lesions.

    PubMed

    Mahadevan, Anand; Bucholz, Richard; Gaya, Andrew M; Kresl, John J; Mantz, Constantine; Minnich, Douglas J; Muacevic, Alexander; Medbery, Clinton; Yang, Jun; Caglar, Hale Basak; Davis, Joanne N

    2014-12-01

    The SRS/SBRT Scientific Meeting 2014, Minneapolis, MN, USA, 7-10 May 2014. The Radiosurgery Society(®), a professional medical society dedicated to advancing the field of stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT), held the international Radiosurgery Society Scientific Meeting, from 7-10 May 2014 in Minneapolis (MN, USA). This year's conference attracted over 400 attendants from around the world and featured over 100 presentations (46 oral) describing the role of SRS/SBRT for the treatment of intracranial and extracranial malignant and nonmalignant lesions. This article summarizes the meeting highlights for SRS/SBRT treatments, both intracranial and extracranial, in a concise review. PMID:25525840

  1. Quantification of interplay and gradient effects for lung stereotactic ablative radiotherapy (SABR) treatments.

    PubMed

    Tyler, Madelaine K

    2016-01-01

    This study quantified the interplay and gradient effects on GTV dose coverage for 3D CRT, dMLC IMRT, and VMAT SABR treatments for target amplitudes of 5-30 mm using 3DVH v3.1 software incorporating 4D Respiratory MotionSim (4D RMS) module. For clinically relevant motion periods (5 s), the interplay effect was small, with deviations in the minimum dose covering the target volume (D99%) of less than ± 2.5% for target amplitudes up to 30 mm. Increasing the period to 60 s resulted in interplay effects of up to ± 15.0% on target D99% dose coverage. The gradient effect introduced by target motion resulted in deviations of up to ± 3.5% in D99% target dose coverage. VMAT treatments showed the largest deviation in dose metrics, which was attributed to the long delivery times in comparison to dMLC IMRT. Retrospective patient analysis indicated minimal interplay and gradient effects for patients treated with dMLC IMRT at the NCCI. PMID:26894347

  2. Cyclooxygenase-2 impairs treatment effects of radiotherapy for cervical cancer by inhibition of radiation-induced apoptosis

    SciTech Connect

    Ishikawa, Hitoshi . E-mail: hisikawa@med.gunma-u.ac.jp; Ohno, Tatsuya; Kato, Shingo; Wakatsuki, Masaru; Iwakawa, Mayumi; Ohta, Toshie M.S.; Imai, Takashi; Mitsuhashi, Norio; Noda, Shin-ei; Nakano, Takashi; Tsujii, Hirohiko

    2006-12-01

    Purpose: Cyclooxygenase-2 (COX-2) plays a pivotal role in regulation of radiation-induced apoptosis. The aim of this study was to analyze the relationship between COX-2 expression and postradiotherapy outcomes of patients with cervical cancer. Methods and Materials: Biopsy specimens from 47 consecutive patients who had undergone definitive radiotherapy alone or radiotherapy combined with chemotherapy between October 2002 and November 2004 were investigated. Results: The COX-2 expression rate of the pretreatment samples was 46.1% {+-} 21.0%, and the apoptotic index (AI) 1 week after start of radiotherapy was 2.1% {+-} 0.9%. There was a significant negative correlation between the pretreatment COX-2 expression and the AI during radiotherapy (r = -0.52, p = 0.0002). Complete response rates were 59% for COX-2-positive patients compared with 80% for COX-2-negative patients (p = 0.12). The 2-year local control rate for COX-2-positive patients was 71.3%, whereas the corresponding rate for COX-2-negative patients was 96.0% (p 0.06). Conclusions: To the best of our knowledge, this is the first report to prove clinically that COX-2 can make cervical squamous cell carcinomas more refractory to radiotherapy by inhibition of radiation-induced apoptosis. Furthermore, expression of COX-2 may be a good indicator to predict local tumor control after radiotherapy. Although long-term results are ultimately needed, the combination therapy of radiotherapy with use of a COX-2 inhibitor could yield improved outcomes for patients with COX-2 expressing cervical cancer.

  3. Is intensity-modulated radiotherapy better than conventional radiation treatment and three-dimensional conformal radiotherapy for mediastinal masses in patients with Hodgkin's disease, and is there a role for beam orientation optimization and dose constraints assigned to virtual volumes?

    SciTech Connect

    Girinsky, Theodore . E-mail: girinsky@igr.fr; Pichenot, Charlotte; Beaudre, Anne; Ghalibafian, Mithra; Lefkopoulos, Dimitri

    2006-01-01

    Purpose: To evaluate the role of beam orientation optimization and the role of virtual volumes (VVs) aimed at protecting adjacent organs at risk (OARs), and to compare various intensity-modulated radiotherapy (IMRT) setups with conventional treatment with anterior and posterior fields and three-dimensional conformal radiotherapy (3D-CRT). Methods and Materials: Patients with mediastinal masses in Hodgkin's disease were treated with combined modality therapy (three to six cycles of adriamycin, bleomycin, vinblastine, and dacarbazine [ABVD] before radiation treatment). Contouring and treatment planning were performed with Somavision and CadPlan Helios (Varian Systems, Palo Alto, CA). The gross tumor volume was determined according to the prechemotherapy length and the postchemotherapy width of the mediastinal tumor mass. A 10-mm isotropic margin was added for the planning target volume (PTV). Because dose constraints assigned to OARs led to unsatisfactory PTV coverage, VVs were designed for each patient to protect adjacent OARs. The prescribed dose was 40 Gy to the PTV, delivered according to guidelines from International Commission on Radiation Units and Measurements Report No. 50. Five different IMRT treatment plans were compared with conventional treatment and 3D-CRT. Results: Beam orientation was important with respect to the amount of irradiated normal tissues. The best compromise in terms of PTV coverage and protection of normal tissues was obtained with five equally spaced beams (5FEQ IMRT plan) using dose constraints assigned to VVs. When IMRT treatment plans were compared with conventional treatment and 3D-CRT, dose conformation with IMRT was significantly better, with greater protection of the heart, coronary arteries, esophagus, and spinal cord. The lungs and breasts in women received a slightly higher radiation dose with IMRT compared with conventional treatments. The greater volume of normal tissue receiving low radiation doses could be a cause for

  4. Feasibility and early clinical assessment of flattening filter free (FFF) based stereotactic body radiotherapy (SBRT) treatments

    PubMed Central

    2011-01-01

    Purpose To test feasibility and safety of clinical usage of Flattening Filter Free (FFF) beams for delivering ablative stereotactic body radiation therapy (SBRT) doses to various tumor sites, by means of Varian TrueBeam™ (Varian Medical Systems). Methods and Materials Seventy patients were treated with SBRT and FFF: 51 lesions were in the thorax (48 patients),10 in the liver, 9 in isolated abdominal lymph node, adrenal gland or pancreas. Doses ranged from 32 to 75 Gy, depending on the anatomical site and the volume of the lesion to irradiate. Lung lesions were treated with cumulative doses of 32 or 48 Gy, delivered in 4 consecutive fractions. The liver patients were treated in 3 fractions with total dose of 75 Gy. The isolated lymph nodes were irradiated in 6 fractions with doses of 45 Gy. The inclusion criteria were the presence of isolated node, or few lymph nodes in the same lymph node region, in absence of other active sites of cancer disease before the SBRT treatment. Results All 70 patients completed the treatment. The minimum follow-up was 3 months. Six cases of acute toxicities were recorded (2 Grade2 and 2 Grade3 in lung and 2 Grade2 in abdomen). No patient experienced acute toxicity greater than Grade3. No other types or grades of toxicities were observed at clinical evaluation visits. Conclusions This study showed that, with respect to acute toxicity, SBRT with FFF beams showed to be a feasible technique in 70 consecutive patients with various primary and metastatic lesions in the body. PMID:21910868

  5. Poster — Thur Eve — 58: Dosimetric validation of electronic compensation for radiotherapy treatment planning

    SciTech Connect

    Gräfe, James; Khan, Rao; Meyer, Tyler

    2014-08-15

    In this study we investigate the deliverability of dosimetric plans generated by the irregular surface compensator (ISCOMP) algorithm for 6 MV photon beams in Eclipse (Varian Medical System, CA). In contrast to physical tissue compensation, the electronic ISCOMP uses MLCs to dynamically modulate the fluence of a photon beam in order to deliver a uniform dose at a user defined plane in tissue. This method can be used to shield critical organs that are located within the treatment portal or improve dose uniformity by tissue compensation in inhomogeneous regions. Three site specific plans and a set of test fields were evaluated using the γ-metric of 3%/ 3 mm on Varian EPID, MapCHECK, and Gafchromic EBT3 film with a clinical tolerance of >95% passing rates. Point dose measurements with an NRCC calibrated ionization chamber were also performed to verify the absolute dose delivered. In all cases the MapCHECK measured plans met the gamma criteria. The mean passing rate for the six EBT3 film field measurements was 96.2%, with only two fields at 93.4 and 94.0% passing rates. The EPID plans passed for fields encompassing the central ∼10 × 10 cm{sup 2} region of the detector; however for larger fields and greater off-axis distances discrepancies were observed and attributed to the profile corrections and modeling of backscatter in the portal dose calculation. The magnitude of the average percentage difference for 21 ion chamber point dose measurements and 17 different fields was 1.4 ± 0.9%, and the maximum percentage difference was −3.3%. These measurements qualify the algorithm for routine clinical use subject to the same pre-treatment patient specific QA as IMRT.

  6. [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

  7. WE-E-BRE-02: BEST IN PHYSICS (THERAPY) - Stereotactic Radiotherapy for Renal Sympathetic Ablation for the Treatment of Refractory Hypertension

    SciTech Connect

    Maxim, P; Wheeler, M; Loo, B; Maguire, P

    2014-06-15

    Purpose: To determine the safety and efficacy of stereotactic radiotherapy as a novel treatment for patients with refractory hypertension in a swine model. Uncontrolled hypertension is a significant contributor to morbidity and mortality, substantially increasing the risk of ischemic stroke, ischemic heart disease, and kidney failure. Methods: High-resolution computed tomography (CT) images of anesthetized pigs were acquired and treatment plans for each renal artery and nerve were developed using our clinically implemented treatment planning system. Stereotactic radiotherapy, 40Gy in single fraction was delivered bilaterally to the renal nerves using a state-of-the-art medical linear accelerator under image guidance utilizing dynamic conformal arcs. Dose to nearby critical organs was evaluated by dosevolume histogram analysis and correlated to toxicity data obtained through follow up pathology analysis. The animals were observed for six months with serial measurements of blood pressure, urine analysis, serum laboratories, and overall clinical and behavioral status. Results: All animals survived to the follow-up point without evidence of renal dysfunction (stable serum creatinine), skin changes, or behavioral changes that might suggest animal discomfort. Plasma norepinephrine levels (ng/ml) were followed monthly for 6 months. The average reduction observed was 63%, with the median reduction at 73.5%. Microscopic evaluation 4–6 weeks after treatment showed evidence of damage to the nerves around treated renal arteries. Considerable attenuation in pan neurofilament expression by immunohistochemistry was observed with some vacuolar changes indicative of injury. There was no histological or immunohistochemical evidence of damage to nearby spinal cord or spinal nerve root structures. Conclusion: Our preclinical studies have shown stereotactic radiotherapy to the renal sympathetic plexus to be safe and effective in reducing blood pressure, thus this approach holds great

  8. Dosimetric Comparison of Bone Marrow-Sparing Intensity-Modulated Radiotherapy Versus Conventional Techniques for Treatment of Cervical Cancer

    SciTech Connect

    Mell, Loren K.; Tiryaki, Hanifi; Ahn, Kang-Hyun; Mundt, Arno J.; Roeske, John C.; Aydogan, Bulent

    2008-08-01

    Purpose: To compare bone marrow-sparing intensity-modulated pelvic radiotherapy (BMS-IMRT) with conventional (four-field box and anteroposterior-posteroanterior [AP-PA]) techniques in the treatment of cervical cancer. Methods and Materials: The data from 7 cervical cancer patients treated with concurrent chemotherapy and IMRT without BMS were analyzed and compared with data using four-field box and AP-PA techniques. All plans were normalized to cover the planning target volume with the 99% isodose line. The clinical target volume consisted of the pelvic and presacral lymph nodes, uterus and cervix, upper vagina, and parametrial tissue. Normal tissues included bowel, bladder, and pelvic bone marrow (PBM), which comprised the lumbosacral spine and ilium and the ischium, pubis, and proximal femora (lower pelvis bone marrow). Dose-volume histograms for the planning target volume and normal tissues were compared for BMS-IMRT vs. four-field box and AP-PA plans. Results: BMS-IMRT was superior to the four-field box technique in reducing the dose to the PBM, small bowel, rectum, and bladder. Compared with AP-PA plans, BMS-IMRT reduced the PBM volume receiving a dose >16.4 Gy. BMS-IMRT reduced the volume of ilium, lower pelvis bone marrow, and bowel receiving a dose >27.7, >18.7, and >21.1 Gy, respectively, but increased dose below these thresholds compared with the AP-PA plans. BMS-IMRT reduced the volume of lumbosacral spine bone marrow, rectum, small bowel, and bladder at all dose levels in all 7 patients. Conclusion: BMS-IMRT reduced irradiation of PBM compared with the four-field box technique. Compared with the AP-PA technique, BMS-IMRT reduced lumbosacral spine bone marrow irradiation and reduced the volume of PBM irradiated to high doses. Therefore BMS-IMRT might reduce acute hematologic toxicity compared with conventional techniques.

  9. Treatment of early clinically staged Hodgkin's disease with a combination of ABVD chemotherapy plus limited field radiotherapy.

    PubMed

    Karmiris, T D; Grigoriou, E; Tsantekidou, M; Spanou, E; Mihalakeas, H; Baltadakis, J; Apostolidis, J; Pagoni, M; Karakasis, D; Bakiri, M; Mitsouli, C; Harhalakis, N; Nikiforakis, E

    2003-09-01

    The current management of early stage Hodgkin's disease (HD) is usually based on clinical staging, combined modality therapy and the use of less toxic chemotherapy regimens. This approach entails high cure rates, while ensures less long term toxicity with avoidance of laparotomy. The aim of this study was to assess the efficacy of a brief course of Adriamycin, Bleomycin, Vinblastine, Dacarbazine (ABVD) chemotherapy followed by limited field radiotherapy (RT) in favorable clinical stage (CS) I and IIA HD. Forty patients, aged 17-68 (median 34) years, with favorable CS I and IIA HD, without bulky mediastinal disease, have been treated with 4-6 (median 4) cycles of ABVD plus limited field RT. Twenty seven (67%) patients received 4 cycles of chemotherapy, while 13 received 5-6 cycles. Thirty five (87%) patients received limited field RT with dose 24-36 Gy and five (13%) received extended field with 36-46 Gy. All patients responded completely to chemotherapy. One patient experienced a relapse two months after the end of therapy. All patients are alive; 39 in continuous complete remission. With a median follow-up period of 44 months (range 18-101) the actuarial overall and progress free survival was 100 and 97% at 5 years. We did not observe any case of secondary leukemia or solid tumor. Pulmonary toxicity was mild in cases of mediastinal irradiation. Considering the short follow-up time and the small number of patients, the combination of a brief course of ABVD plus regional RT is a very efficacious treatment of favorable CS I and IIA HD with mild toxicity. However, long term survival data are needed, which could give confident answers regarding the risk of late therapy related complications, particularly second malignancies. PMID:14565654

  10. The Essential Role of Radiotherapy in the Treatment of Merkel Cell Carcinoma: A Study From the Rare Cancer Network

    SciTech Connect

    Ghadjar, Pirus; Kaanders, Johannes H.; Poortmans, Philipp; Zaucha, Renata; Krengli, Marco; Lagrange, Jean L.; Oezsoy, Orhan; Nguyen, Tan D.; Miralbell, Raymond; Baize, Adele; Boujelbene, Noureddine; Collen, Timothy; Scandolaro, Luciano; Untereiner, Michel; Goldberg, Hadassah; Pesce, Gianfranco A.; Anacak, Yavuz; Friedrich, Esther E.; Aebersold, Daniel M.; Beer, Karl T.

    2011-11-15

    Purpose: To evaluate the role of postoperative radiotherapy (RT) in Merkel cell carcinoma (MCC). Methods and Materials: A retrospective multicenter study was performed in 180 patients with MCC treated between February 1988 and September 2009. Patients who had had surgery alone were compared with patients who received surgery and postoperative RT or radical RT. Local relapse-free survival (LRFS), regional relapse-free survival (RRFS), and distant metastasis-free survival (DMFS) rates were assessed together with disease-free survival (DFS), cancer-specific survival (CSS), and overall survival (OS) rates. Results: Seventy-nine patients were male and 101 patients were female, and the median age was 73 years old (range, 38-93 years). The majority of patients had localized disease (n = 146), and the remaining patients had regional lymph node metastasis (n = 34). Forty-nine patients underwent surgery for the primary tumor without postoperative RT to the primary site; the other 131 patients received surgery for the primary tumor, followed by postoperative RT (n = 118) or a biopsy of the primary tumor followed by radical RT (n = 13). Median follow-up was 5 years (range, 0.2-16.5 years). Patients in the RT group had improved LRFS (93% vs. 64%; p < 0.001), RRFS (76% vs. 27%; p < 0.001), DMFS (70% vs. 42%; p = 0.01), DFS (59% vs. 4%; p < 0.001), and CSS (65% vs. 49%; p = 0.03) rates compared to patients who underwent surgery for the primary tumor alone; LRFS, RRFS, DMFS, and DFS rates remained significant with multivariable Cox regression analysis. However OS was not significantly improved by postoperative RT (56% vs. 46%; p = 0.2). Conclusions: After multivariable analysis, postoperative RT was associated with improved outcome and seems to be an important component in the multimodality treatment of MCC.

  11. Primary Tumor Site as a Predictor of Treatment Outcome for Definitive Radiotherapy of Advanced-Stage Oral Cavity Cancers

    SciTech Connect

    Lin, Chien-Yu; Wang, Hung-Ming; Kang, Chung-Jan; Lee, Li-Yu; Huang, Shiang-Fu; Fan, Kang-Hsing; Chen, Eric Yen-Chao

    2010-11-15

    Purpose: To evaluate the outcome of definitive radiotherapy (RT) for oral cavity cancers and to assess prognostic factors. Methods and Materials: Definitive RT was performed on 115 patients with oral cavity cancers at Stages III, IVA, and IVB, with a distribution of 6%, 47%, and 47%, respectively. The median dose of RT was 72Gy (range, 62-76Gy). Cisplatin-based chemotherapy was administered to 95% of the patients. Eleven patients underwent salvage surgery after RT failure. Results: Eight-eight (76.5%) patients responded partially and 23 (20%) completely; of the patients who responded, 18% and 57%, respectively, experienced a durable effect of treatment. The 3-year overall survival, disease-specific survival, and progression-free survival were 22%, 27%, and 25%, respectively. The 3-year PFS rates based on the primary tumor sites were as follows: Group I (buccal, mouth floor, and gum) 51%, Group II (retromolar and hard palate) 18%, and Group III (tongue and lip) 6% (p < 0.0001). The 3-year progression-free survival was 41% for N0 patients and 19% for patients with N+ disease (p = 0.012). The T stage and RT technique did not affect survival. The patients who underwent salvage surgery demonstrated better 3-year overall survival and disease-specific survival (53% vs. 19%, p = 0.015 and 53% vs. 24%, p = 0.029, respectively). Subsite group, N+, and salvage surgery were the only significant prognostic factors for survival after multivariate analysis. Conclusion: The primary tumor site and neck stage are prognostic predictors in advanced-stage oral cancer patients who received radical RT. The primary tumor extension and RT technique did not influence survival.

  12. Clinical and endocrine responses to pituitary radiotherapy in pediatric Cushing's disease: an effective second-line treatment.

    PubMed

    Storr, Helen L; Plowman, P Nicholas; Carroll, Paul V; François, Inge; Krassas, Gerasimos E; Afshar, Farhad; Besser, G Michael; Grossman, Ashley B; Savage, Martin O

    2003-01-01

    Transsphenoidal surgery (TSS) is considered first-line treatment for Cushing's disease (CD). Options for treatment of postoperative persisting hypercortisolemia are pituitary radiotherapy (RT), repeat TSS, or bilateral adrenalectomy. From 1983 to 2001, we treated 18 pediatric patients (age, 6.4-17.8 yr) with CD. All underwent TSS, and 11 were cured (postoperative serum cortisol, <50 nM). Seven (39%) had 0900-h serum cortisol of 269-900 nM during the immediate postoperative period (2-20 d), indicating lack of cure. These patients (6 males and 1 female; mean age, 12.8 yr; range, 6.4-17.8 yr; 4 prepubertal; 3 pubertal) received external beam RT to the pituitary gland, using a 6-MV linear accelerator, with a dose of 45 Gy in 25 fractions over 35 d. Until the RT became effective, hypercortisolemia was controlled with ketoconazole (dose, 200-600 mg/d) (n = 4) and metyrapone (750 mg-3 g/d) +/- aminoglutethimide (1 g/d) or o'p'DDD (mitotane, 3 mg/d) (n = 3). All patients were cured after pituitary RT. The mean interval from RT to cure (mean serum cortisol on 5-point day curve, <150 nM) was 0.94 yr (0.25-2.86 yr). Recovery of pituitary-adrenal function (mean cortisol, 150-300 nM) occurred at mean 1.16 yr (0.40-2.86 yr) post RT. At 2 yr post RT, puberty occurred early in one male patient (age, 9.8 yr) but was normal in the others. GH secretion was assessed at 0.6-2.5 yr post RT in all patients: six had GH deficiency (peak on glucagon/insulin provocation, <1.0-17.9 mU/liter) and received human GH replacement. Follow-up of pituitary function 7.6 and 9.5 yr post RT in two patients showed normal gonadotropin secretion and recovery of GH peak to 29.7 and 19.2 mU/liter. The seven patients were followed for mean 6.9 yr (1.4-12.0 yr), with no evidence of recurrence of CD. In conclusion, pituitary RT is an effective and relatively rapid-onset treatment for pediatric CD after failure of TSS. GH deficiency occurred in 86% patients. Long-term follow-up suggests some recovery of GH

  13. Biosocial processes predicting multisystemic therapy treatment response.

    PubMed

    Ryan, Stacy R; Brennan, Patricia A; Cunningham, Phillippe B; Foster, Sharon L; Brock, Rebecca L; Whitmore, Elizabeth

    2013-02-01

    This study examined biological (testosterone) and social (deviant peer affiliation) factors early in treatment as predictors of treatment outcome among adolescent boys receiving Multisystemic Therapy (MST) in community settings. Outcome variables included changes in youth aggression and delinquency as reported by the primary caregiver. Testosterone and deviant peer affiliation were assessed at treatment onset; and outcome variables (aggression and delinquency) were assessed at treatment onset, mid-treatment and end-of-treatment. Participants were 112 adolescent boys (M age=15.42, SD=1.31) and their caregivers. Growth curve analyses revealed that the combination of high testosterone and high deviant peer affiliation early in treatment were significantly associated with less of a decline in aggression and delinquency over the course of treatment. Results provide novel evidence for the role of testosterone in the prediction of future externalizing behaviors. Clinical and theoretical implications are discussed. PMID:23247043

  14. K Basin sludge treatment process description

    SciTech Connect

    Westra, A.G.

    1998-08-28

    The K East (KE) and K West (KW) fuel storage basins at the 100 K Area of the Hanford Site contain sludge on the floor, in pits, and inside fuel storage canisters. The major sources of the sludge are corrosion of the fuel elements and steel structures in the basin, sand intrusion from outside the buildings, and degradation of the structural concrete that forms the basins. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be treated so that it meets Tank Waste Remediation System (TWRS) acceptance criteria and can be sent to one of the double-shell waste tanks. The US Department of Energy, Richland Operations Office accepted a recommendation by Fluor Daniel Hanford, Inc., to chemically treat the sludge. Sludge treatment will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and reacting the solution with caustic to co-precipitate the uranium and plutonium. A truck will transport the resulting slurry to an underground storage tank (most likely tank 241-AW-105). The undissolved solids will be treated to reduce the transuranic (TRU) and content, stabilized in grout, and transferred to the Environmental Restoration Disposal Facility (ERDF) for disposal. This document describes a process for dissolving the sludge to produce waste streams that meet the TWRS acceptance criteria for disposal to an underground waste tank and the ERDF acceptance criteria for disposal of solid waste. The process described is based on a series of engineering studies and laboratory tests outlined in the testing strategy document (Flament 1998).

  15. Statistical analysis of surrogate signals to incorporate respiratory motion variability into radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Wilms, Matthias; Ehrhardt, Jan; Werner, René; Marx, Mirko; Handels, Heinz

    2014-03-01

    Respiratory motion and its variability lead to location uncertainties in radiation therapy (RT) of thoracic and abdominal tumors. Current approaches for motion compensation in RT are usually driven by respiratory surrogate signals, e.g., spirometry. In this contribution, we present an approach for statistical analysis, modeling and subsequent simulation of surrogate signals on a cycle-by-cycle basis. The simulated signals represent typical patient-specific variations of, e.g., breathing amplitude and cycle period. For the underlying statistical analysis, all breathing cycles of an observed signal are consistently parameterized using approximating B-spline curves. Statistics on breathing cycles are then performed by using the parameters of the B-spline approximations. Assuming that these parameters follow a multivariate Gaussian distribution, realistic time-continuous surrogate signals of arbitrary length can be generated and used to simulate the internal motion of tumors and organs based on a patient-specific diffeomorphic correspondence model. As an example, we show how this approach can be employed in RT treatment planning to calculate tumor appearance probabilities and to statistically assess the impact of respiratory motion and its variability on planned dose distributions.

  16. Impact of track structure calculations on biological treatment planning in ion radiotherapy

    NASA Astrophysics Data System (ADS)

    Elsässer, Thilo; Cunrath, Richard; Krämer, Michael; Scholz, Michael

    2008-07-01

    Treatment planning for ion therapy requires precise knowledge about the biological effectiveness of particle beams, which is strongly determined by the microscopic radial energy deposition around individual ion tracks. We analyse different amorphous track structure models based on simple analytical formulae as well as on radial dose distributions derived by means of Monte Carlo simulations. Moreover, these track structure representations are used as input for the local effect model (LEM) in order to determine their impact on the relative biological effectiveness (RBE) of cell inactivation. It demonstrates the relevance of the inner part of the ion track with a radius of the order of a few nanometres. We show that simple analytical formulae for the radial dose distributions give good results for the prediction of cell inactivation. However, they strongly depend on the assumptions about the local dose in the track core. Additionally, we discuss the interdependence of track structure calculations with other model constituents such as target size and the choice of the biological input data for conventional photon irradiation.

  17. Prospective multicenter study of combined treatment with chemotherapy and radiotherapy in breast cancer women with the rare clinical scenario of ipsilateral supraclavicular node recurrence without distant metastases

    SciTech Connect

    Pergolizzi, Stefano . E-mail: Stefano.Pergolizzi@unime.it; Adamo, Vincenzo; Russi, Elvio; Santacaterina, Anna; Maisano, Roberto; Numico, Gianmauro; Palazzolo, Carmela; Ferrau, Francesco; Settineri, Nicola; Altavilla, Giuseppe; Girlando, Andrea; Spadaro, Pietro; Cascinu, Stefano

    2006-05-01

    Purpose: To evaluate the role of chemotherapy combined with curative radiotherapy in breast cancer patients who presented with recurrent ipsilateral supraclavicular lymph node metastases (ISLM) without 'nonregional disease,' we designed an observational study performed prospectively. Patients and Methods: Forty-four consecutive patients with ISLM from breast cancer as part of recurrent regional disease without distant metastases were included in this study. All patients received chemotherapy with doxorubicin-based schema or paclitaxel for six courses and curative radiotherapy (60 Gy/30 fractions of 2 Gy/5 days a week). An 'involved field' radiation was delivered during the interval between the third and fourth chemotherapy course; hormonal therapy was given based on receptor status. Results: The rate of overall clinical response after chemotherapy and radiotherapy was 94.9%. Median time to progression and overall survival were 28 and 40 months, respectively; the 5-year actuarial overall survival and disease-free survival rates were 35% (95% confidence interval, 19-51) and 20% (95% confidence interval, 6-34), respectively. Conclusion: A curative course of intravenous chemotherapy and radical irradiation is feasible in patients with ISLM. All patients presenting recurrence in supraclavicular nodes should be treated with definitive locoregional treatments and systemic therapy because the outcomes are better than might be historically assumed.

  18. SU-E-T-417: A Method for Predicting and Correcting the Dosimetric Effect of a Radiotherapy Treatment Couch in Actual Treatment Position

    SciTech Connect

    Duan, J; Shen, S; Wu, X; Huang, M; Benhabib, S; Cardan, R; Popple, R; Brezovich, I

    2014-06-01

    Purpose: Although radiation attenuation by the treatment couch can be included in the calculation of radiotherapy dose, difference between planned and actual treatment couch positions can generate significant dose discrepancies. We propose a method to predict and correct the dosimetric effect of the couch in actual treatment position. Methods: The couch transmission factor, T, varies with beam angle, G, couch lateral position, x, and vertical position, y, i.e., T=T(x,y,G). If T(x,y,G) is known for a fixed couch vertical position y=h, the transmission of central-axis beam (CAX) T(x,y,G) can be obtained by T(x,y,G)=T(x{sup +},h,G), where x{sup +}=x-(y-h)tan(G) and G is the angle between the beam and the vertical axis. Similarly, the transmission of any off-CAX point can be obtained using a similar formula. We measured CAX couch transmission at a fixed couch vertical position over the couch lateral motion range for all gantry angles by continuously scanning rotating arc beams. A 2D couch transmission correction matrix can thus be generated from T(x,h,G) for each treatment field for the actual couch position. By applying the transmission correction matrix to the planned field dose, the couch effect can be predicted and corrected. To verify this method, we measured couch transmission T(x, y=10cm, G=225°)(225°=IEC 135°) and compared to that obtained from equivalent T(x{sup +}, y=3cm, G=225°) over the range of lateral motion with a step size of 2 cm . Results: The measured couch transmission factors T(x, y=10cm, G=225°) are in excellent agreement with those obtained from the equivalent T(x{sup +}, y=3cm, G=225°). The mean difference is 0.00406±0.00135. Conclusion: The couch transmission correction matrix for any couch position and beam angle can be obtained from one set of scanning measurements at a fixed couch vertical position. The dosimetric effect of the treatment couch can be predicted and corrected by applying the couch transmission correction to the planned

  19. Phase I Clinical Trial Assessing Temozolomide and Tamoxifen With Concomitant Radiotherapy for Treatment of High-Grade Glioma

    SciTech Connect

    Patel, Shilpen; DiBiase, Steven; Meisenberg, Barry; Flannery, Todd; Patel, Ashish; Dhople, Anil; Cheston, Sally; Amin, Pradip

    2012-02-01

    Purpose: The new standard treatment of glioblastoma multiforme is concurrent radiotherapy (RT) and temozolomide. The proliferation of high-grade gliomas might be partly dependent on protein kinase C-mediated pathways. Tamoxifen has been shown in vitro to inhibit protein kinase C through estrogen receptor-independent antineoplastic effects. This Phase I trial was designed to determine the maximal tolerated dose (MTD) of tamoxifen when given with temozolomide and concurrent RT to patients with high-grade gliomas. Methods and Materials: A total of 17 consecutive patients in four cohorts with World Health Organization Grade 3 (n = 2) and 4 (n = 15) gliomas were given tamoxifen twice daily during 6 weeks of concurrent RT and temozolomide. Eligibility included histologic diagnosis, age >18 years old, Karnofsky performance status {>=}60, and no previous brain RT or chemotherapy. The starting dose was 50 mg/m{sup 2} divided twice daily. If no dose-limiting toxicities (DLTs) occurred in 3 patients, the dose was escalated in 25-mg/m{sup 2} increments until the MTD was reached. When {>=}2 patients within a cohort experienced a DLT, the MTD had been exceeded. Temozolomide was given with RT at 75 mg/m{sup 2}. A dose of 60 Gy in 2 Gy/d fractions to a partial brain field was delivered. Results: A total of 6 patients in Cohort 4 had received tamoxifen at 125 mg/m{sup 2}. One patient was excluded, and the fourth patient developed Grade 4 thrombocytopenia (DLT). Thus, 3 more patients needed to be enrolled. A deep venous thrombosis (DLT) occurred in the sixth patient. Thus, the MTD was 100 mg/m{sup 2}. Conclusions: The MTD of tamoxifen was 100 mg/m{sup 2} when given concurrently with temozolomide 75 mg/m{sup 2} and RT. Tamoxifen might have a role in the initial treatment of high-grade gliomas and should be studied in future Phase II trials building on the newly established platform of concurrent chemoradiotherapy.

  20. Dosimetric comparison of different multileaf collimator leaves in treatment planning of intensity-modulated radiotherapy for cervical cancer

    SciTech Connect

    Wang, Shichao; Ai, Ping; Xie, Li; Xu, Qingfeng; Bai, Sen; Lu, You; Li, Ping; Chen, Nianyong

    2013-01-01

    To study the effect of multileaf collimator (MLC) leaf widths (standard MLC [sMLC] width of 10 mm and micro-MLC [mMLC] width of 4 mm) on intensity-modulated radiotherapy (IMRT) for cervical cancer. Between January 2010 and August 2010, a retrospective analysis was conducted on 12 patients with cervical cancer. The treatment plans for all patients were generated with the same machine setup parameters and optimization methods in a treatment planning system (TPS) based on 2 commercial Elekta MLC devices. The dose distribution for the planning tumor volume (PTV), the dose sparing for organs at risk (OARs), the monitor units (MUs), and the number of IMRT segments were evaluated. For the delivery efficiency, the MUs were significantly higher in the sMLC-IMRT plan than in the mMLC-IMRT plan (802 ± 56.9 vs 702 ± 56.7; p < 0.05). The number of segments in the plans were 58.75 ± 1.8 and 59 ± 1.04 (p > 0.05). For the planning quality, the conformity index (CI) between the 2 paired IMRT plans with the mMLC and the sMLC did not differ significantly (average: 0.817 ± 0.024 vs 0.810 ± 0.028; p > 0.05). The differences of the homogeneity index (HI) between the 2 paired plans were statistically significant (average: 1.122 ± 0.010 vs 1.132 ± 0.014; p < 0.01). For OARs, the rectum, bladder, small intestine, and bony pelvis were evaluated in terms of V{sub 10}, V{sub 20}, V{sub 30}, and V{sub 40}, percentage of contoured OAR volumes receiving 10, 20, 30, and 40 Gy, respectively, and the mean dose (D{sub mean}) received. The IMRT plans with the mMLC protected the OARs better than the plans with the sMLC. There were significant differences (p < 0.05) in evaluated parameters between the 2 paired IMRT plans, except for V{sub 30} and V{sub 40} of the rectum and V{sub 10}, V{sub 20}, V{sub 40}, and D{sub mean} of the bladder. IMRT plans with the mMLC showed advantages over the plans with the sMLC in dose homogeneity for targets, dose sparing of OARs, and fewer MUs in cervical cancer.

  1. Immune-modulating properties of ionizing radiation: rationale for the treatment of cancer by combination radiotherapy and immune checkpoint inhibitors.

    PubMed

    Derer, Anja; Frey, Benjamin; Fietkau, Rainer; Gaipl, Udo S

    2016-07-01

    Radiotherapy (RT) utilizes the DNA-damaging properties of ionizing radiation to control tumor growth and ultimately kill tumor cells. By modifying the tumor cell phenotype and the tumor microenvironment, it may also modulate the immune system. However, out-of-field reactions of RT mostly assume further immune activation. Here, the sequence of the applications of RT and immunotherapy is crucial, just as the dose and fractionation may be. Lower single doses may impact on tumor vascularization and immune cell infiltration in particular, while higher doses may impact on intratumoral induction and production of type I interferons. The induction of immunogenic cancer cell death seems in turn to be a common mechanism for most RT schemes. Dendritic cells (DCs) are activated by the released danger signals and by taking up tumor peptides derived from irradiated cells. DCs subsequently activate T cells, a process that has to be tightly controlled to ensure tolerance. Inhibitory pathways known as immune checkpoints exist for this purpose and are exploited by tumors to inhibit immune responses. Cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) on T cells are two major checkpoints. The biological concepts behind the findings that RT in combination with anti-CTLA-4 and/or anti-PD-L1 blockade stimulates CD8+ T cell-mediated anti-tumor immunity are reviewed in detail. On this basis, we suggest clinically significant combinations and sequences of RT and immune checkpoint inhibition. We conclude that RT and immune therapies complement one another. PMID:26590829

  2. The effect of exercise therapy in head and neck cancer patients in the treatment of radiotherapy-induced trismus: A systematic review.

    PubMed

    Scherpenhuizen, Anne; van Waes, Anne M A; Janssen, Luuk M; Van Cann, Ellen M; Stegeman, Inge

    2015-08-01

    Trismus is characterized by a reduced ability to open the mouth, directly affecting many aspects of daily life, such as chewing, swallowing, speaking and maintaining oral hygiene. Several studies have shown that trismus affects health related quality of life. Radiotherapy in the head and neck area is identified as one of the most frequent causes of trismus in head and neck cancer (HNC) patients. Currently, there is no standard treatment for trismus. Several stretching techniques and jaw mobilizing devices are available, but their effect in radiotherapy-induced trismus is still largely unknown. With this review we give an overview of the present relevant literature and compare the effect of exercise therapy versus no exercise therapy on jaw mobility, expressed in millimeters mouth opening, in HNC patients with radiotherapy-induced trismus. A systematic literature search in four electronic bibliographic databases was conducted in July 2014. Selected articles were critically appraised on relevance and validity. Best available evidence was analyzed and compared. Three of the four selected articles show a significant increase (p-value<0.05) in maximal interincisal opening (MIO) after exercise therapy using a jaw-mobilizing device. One article reports a significant decrease in MIO. However, this decrease is less in the intervention group, which implies a positive effect of exercise therapy. Based on this current best clinical evidence, it can be assumed that exercise therapy with a jaw-mobilizing device yields better results than no exercise, with regards to opening of the mouth in HNC patients with radiotherapy-induced trismus. PMID:26058916

  3. Maraging superalloys and heat treatment processes

    DOEpatents

    Korenko, Michael K.; Gelles, David S.; Thomas, Larry E.

    1986-01-01

    Described herein are nickel-chromium-iron maraging, gamma prime strengthened superalloys containing about 18 to 25 weight percent nickel, about 4 to 8 weight percent chromium, gamma prime forming elements such as aluminum and/or titanium, and a solid solution strengthening element, such as molybdenum. After heat treatment, which includes at least one ausaging treatment and at least one maraging treatment, a microstructure containing gamma prime phase and decomposed Fe-Ni-Cr type martensite is produced.

  4. Quality improvement process to assess tattoo alignment, set-up accuracy and isocentre reproducibility in pelvic radiotherapy patients

    PubMed Central

    Elsner, Kelly; Francis, Kate; Hruby, George; Roderick, Stephanie

    2014-01-01

    Introduction This quality improvement study tested three methods of tattoo alignment and isocentre definition to investigate if aligning lateral tattoos to minimise pitch, roll and yaw decreased set-up error, and if defining the isocentre using the lateral tattoos for cranio-caudal (CC) position improved isocentre reproducibility. The study population was patients receiving curative external beam radiotherapy (EBRT) for prostate cancer. The results are applicable to all supine pelvic EBRT patients. Methods The three sequential cohorts recruited 11, 11 and 10 patients respectively. A data set of 20 orthogonal pairs of electronic portal images (EPI) was acquired for each patient. EPIs were matched offline to digitally reconstructed radiographs. In cohort 1, lateral tattoos were adjusted to minimise roll. The anterior tattoo was used to define the isocentre. In cohort 2, lateral tattoos were aligned to minimise roll and yaw. Isocentre was defined as per cohort 1. In cohort 3, lateral tattoos were aligned as per cohort 2 and the anterior tattoo was adjusted to minimise pitch. Isocentre was defined by the lateral tattoos for CC position and the anterior tattoo for the left–right position. Results Cohort 3 results were superior as CC systematic and random set-up errors reduced from −1.3 mm to −0.5 mm, and 3.1 mm to 1.4 mm respectively, from cohort 1 to cohort 3. Isocentre reproducibility also improved from 86.7% to 92.1% of treatment isocentres within 5 mm of the planned isocentre. Conclusion The methods of tattoo alignment and isocentre definition in cohort 3 reduced set-up errors and improved isocentre reproducibility. PMID:25598978

  5. Accelerated Radiotherapy, Carbogen, and Nicotinamide (ARCON) in the Treatment of Advanced Bladder Cancer: Mature Results of a Phase II Nonrandomized Study

    SciTech Connect

    Hoskin, Peter; Rojas, Ana Ph.D. Saunders, Michele

    2009-04-01

    Purpose: We previously showed that accelerated radiotherapy combined with carbogen and nicotinamide (ARCON) was an effective approach to use in the radical treatment of patients with advanced bladder carcinoma. Interim analysis from this Phase II study showed that it achieved a high level of locoregional control and overall survival (OS) and an acceptable level of adverse events. Methods and Materials: From 1994 to 2000, a total of 105 consecutive patients with high-grade superficial or muscle-invasive bladder carcinoma were given accelerated radiotherapy (50-55 Gy in 4 weeks) with carbogen alone or ARCON. End points of the study were OS, disease-specific, and local regional relapse-free survival, and for late adverse events, urinary (altered urination frequency, incontinence, hematuria, and urgency) and bowel dysfunction (stool frequency and blood loss). Results: At 5 and 10 years, local regional relapse-free survival rates were 44% after ARCON excluding the effect of salvage treatment and 62% after ARCON including the effect of salvage treatment (p = 0.04). Five- and 10-year rates were 35% and 27% for OS and 47% and 46% for disease-specific survival. The highest actuarial rate for Grade 3 or worse late urinary or bowel dysfunction was observed for altered urinary frequency (44% of patients had urinary events every 1 hour or less) and stool frequency of four or more events (26% at 5 years). Conclusions: Historic comparisons with other studies indicate no evidence of an increase in severe or worse adverse events and good permanent control of bladder disease after ARCON radiotherapy.

  6. Dynamic targeting image-guided radiotherapy

    SciTech Connect

    Huntzinger, Calvin; Munro, Peter; Johnson, Scott; Miettinen, Mika; Zankowski, Corey; Ahlstrom, Greg; Glettig, Reto; Filliberti, Reto; Kaissl, Wolfgang; Kamber, Martin; Amstutz, Martin; Bouchet, Lionel; Klebanov, Dan; Mostafavi, Hassan; Stark, Richard

    2006-07-01

    Volumetric imaging and planning for 3-dimensional (3D) conformal radiotherapy and intensity-modulated radiotherapy (IMRT) have highlighted the need to the oncology community to better understand the geometric uncertainties inherent in the radiotherapy delivery process, including setup error (interfraction) as well as organ motion during treatment (intrafraction). This has ushered in the development of emerging technologies and clinical processes, collectively referred to as image-guided radiotherapy (IGRT). The goal of IGRT is to provide the tools needed to manage both inter- and intrafraction motion to improve the accuracy of treatment delivery. Like IMRT, IGRT is a process involving all steps in the radiotherapy treatment process, including patient immobilization, computed tomogaphy (CT) simulation, treatment planning, plan verification, patient setup verification and correction, delivery, and quality assurance. The technology and capability of the Dynamic Targeting{sup TM} IGRT system developed by Varian Medical Systems is presented. The core of this system is a Clinac (registered) or Trilogy{sup TM} accelerator equipped with a gantry-mounted imaging system known as the On-Board Imager{sup TM} (OBI). This includes a kilovoltage (kV) x-ray source, an amorphous silicon kV digital image detector, and 2 robotic arms that independently position the kV source and imager orthogonal to the treatment beam. A similar robotic arm positions the PortalVision{sup TM} megavoltage (MV) portal digital image detector, allowing both to be used in concert. The system is designed to support a variety of imaging modalities. The following applications and how they fit in the overall clinical process are described: kV and MV planar radiographic imaging for patient repositioning, kV volumetric cone beam CT imaging for patient repositioning, and kV planar fluoroscopic imaging for gating verification. Achieving image-guided motion management throughout the radiation oncology process

  7. The long term follow-up of early stage follicular lymphoma treated with radiotherapy, chemotherapy or combined modality treatment.

    PubMed

    Sancho, Juan-Manuel; García, Olga; Mercadal, Santiago; Pomares, Helena; Fernández-Alvarez, Rubén; González-Barca, Eva; Tapia, Gustavo; González-García, Esther; Moreno, Miriam; Domingo-Domènech, Eva; Sorigué, Marc; Navarro, José-Tomás; Motlló, Cristina; Fernández-de-Sevilla, Alberto; Feliu, Evarist; Ribera, Josep-Maria

    2015-08-01

    Local (involved-field or recently involved-site) radiotherapy is the standard therapy in limited-stage follicular lymphoma (FL). We retrospectively analyzed the value of chemotherapy in 130 patients with limited-stage FL (46 treated with radiotherapy alone [RT group], 30 with radiotherapy plus chemotherapy [COMBINED group] and 43 with chemotherapy alone [CHEMO group], 11 were managed with observation). Ninety-six percent of patients responded (RT 98%, COMBINED 100%, CHEMO 91%, p=0.179), and 37% (40/107) of patients in complete response relapsed (RT 42%, COMBINED 27%, CHEMO 41%, p=0.371). Progression-free survival (PFS) and overall survival (OS) probabilities at 10 years were similar in RT, COMBINED and CHEMO patients (PFS 41%, 61% and 39% [p=0.167], and OS 77%, 81% and 72% [p=0.821], respectively), while the COMBINED group showed a trend to better time-to-progression (TTP 43%, 72% and 47% [p=0.055]). On multivariate analysis, only a FLIPI score ≥2 showed a trend to influence PFS (HR 2.1 [95% confidence interval 0.9-4.6], p=0.067), and OS (HR 2.4 [0.9-6.5], p=0.084), while patients treated with radiotherapy plus chemotherapy (COMBINED group) showed a significantly better TTP compared with those receiving only RT (HR 0.3 [0.1-0.8], p=0.024). In our study no benefit was observed in survival with the use of systemic therapy compared with local radiotherapy. PMID:26122511

  8. Intraoperative electron boost radiation followed by moderate doses of external beam radiotherapy in limb-sparing treatment of patients with extremity soft-tissue sarcoma

    SciTech Connect

    Oertel, Susanne; Treiber, Martina; Zahlten-Hinguranage, Angelika; Eichin, Steffen; Roeder, Falk; Funk, Angela; Hensley, Frank W.; Timke, Carmen; Niethammer, Andreas G.; Huber, Peter E.; Weitz, Juergen; Eble, Micheal J.; Buchler, Markus W.; Bernd, Ludger; Debus, Juergen; Krempien, Robert C. . E-mail: robert_krempien@med.uni-heidelberg.de

    2006-04-01

    Purpose: To analyze long-term prognosis and morbidity after limb-sparing treatment of patients with extremity soft-tissue sarcoma, with intraoperative electron boost radiotherapy (IOERT) followed by a moderate dose of external beam radiotherapy (EBRT). Methods and Materials: A total of 153 patients who were treated in a single center from 1991 to 2004 were evaluated. Median IOERT dose was 15 Gy, mean EBRT dose 43 Gy (range, 40-50.4 Gy) in conventional fractionation (1.8-2 Gy). Median duration of follow-up was 33 months. Acute toxicity was assessed with Common Toxicity Criteria; late toxic effects were scored according to European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group criteria. Results: Five-year overall survival and 5-year local control rates were 77% and 78%, respectively. Whereas tumor size, patient age, and EBRT dose did not significantly affect outcome, resection status and grading were significant for survival; resection status and IOERT dose were significant for local control. Extremity salvage until death or time of follow-up was achieved in 90% of our patients, 86% of whom showed excellent limb function without impairment in activities of daily life. Acute toxicity Grade 2-4 was observed in 23% and late toxicity Grade 2-4 in 17% of patients. Conclusions: Treatment with IOERT combined with moderate doses of external beam irradiation yields high local control and extremity preservation rates in resected extremity soft-tissue sarcoma.

  9. The Use of Biodegradable Stents in Malignant Oesophageal Strictures for the Treatment of Dysphagia Before Neoadjuvant Treatment or Radical Radiotherapy: A Feasibility Study

    SciTech Connect

    Krokidis, Miltiadis Burke, Chris; Spiliopoulos, Stavros; Gkoutzios, Panos; Hynes, Orla; Ahmed, Irfan; Dourado, Renato; Sabharwal, Tarun; Mason, Robert; Adam, Andreas

    2013-08-01

    PurposeTo evaluate the clinical results of the use of biodegradable oesophageal stents in malignant strictures.MethodsEleven patients were included in this prospective analysis in which a woven polydioxanone biodegradable oesophageal stent was used. The inclusion criterion was that the patient underwent neoadjuvant treatment or radical radiotherapy after the stent insertion. Primary end points were dysphagia score at discharge, stent patency, and complication rate. Secondary end points were overall survival and surgical outcome of surgery.ResultsThere was a 100 % procedure technical success rate. Early complications occurred in three patients resulting in failure to restore oral nutrition. In the remaining eight patients, dysphagia was significantly improved at discharge. Mean stent patency rate in this group was 71.5 days. Stent dysfunction occurred in five of eight patients (62.5 %); in two of five patients this was due to local inflammatory reaction, and in three of five patients it was due to tumour growth after a mean time of 97.8 days, and a new metallic stent was consequently placed in four of five patients. One patient was successfully treated with esophagectomy. At the end of follow-up (mean time 102.1 days), three of eight stents were patent. The overall patient survival rate was 81.8 %.ConclusionAlthough short-term dysphagia scores improved, biodegradable stents do not appear to offer a clear beneficial effect in most cases of malignant strictures, particularly due to a local inflammatory reaction that may be induced. Technical improvement of the device and delineation of the patient group that would benefit from its use is necessary if further studies are to be conducted in the future.

  10. DEMONSTRATION BULLETIN: ZENOGEM™ WASTEWATER TREATMENT PROCESS - ZENON ENVIRONMENTAL SYSTEMS

    EPA Science Inventory

    Zenon Environmental Systems (Zenon) has developed the ZenoGem™ process to remove organic compounds from wastewater by integrating biological treatment and membrane-based ultrafiltration. This innovative system combines biological treatment to remove biodegradable organic compou...

  11. Dosimetric and clinical toxicity comparison of critical organ preservation with three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and RapidArc for the treatment of locally advanced cancer of the pancreatic head

    PubMed Central

    Jin, L.; Wang, R.; Jiang, S.; Yue, J.; Liu, T.; Dou, X.; Zhu, K.; Feng, R.; Xu, X.; Chen, D.; Yin, Y.

    2016-01-01

    Purpose We compared dosimetry and clinical toxicity for 3-dimensional conformal radiotherapy (3D-crt), intensity-modulated radiotherapy (imrt), and RapidArc (Varian Medical Systems, Palo Alto, CA, U.S.A.) in locally advanced pancreatic cancer (lapcc). We hypothesized that the technique with better sparing of organs at risk (oars) and better target dose distributions could lead to decreased clinical toxicity. Methods The study analyzed 280 patients with lapcc who had undergone radiotherapy. The dosimetry comparison was performed using 20 of those patients. Dose–volume histograms for the target volume and the oars were compared. The clinical toxicity comparison used the 280 patients who received radiation with 3D-crt, imrt, or RapidArc. Results Compared with 3D-crt, RapidArc and imrt both achieved a better conformal index, homogeneity index, V95%, and V110%. Compared with 3D-crt or imrt, RapidArc reduced the V10, V20, and mean dose to duodenum, the V20 of the right kidney, and the liver mean dose. Compared with 3D-crt, RapidArc reduced the V35, and V45 of duodenum, the mean dose to small bowel, and the V15 of right kidney. The incidences of grades 3 and 4 diarrhea (p = 0.037) and anorexia (p = 0.042) were lower with RapidArc than with 3D-crt, and the incidences of grades 3 and 4 diarrhea (p = 0.027) were lower with RapidArc than with imrt. Conclusions Compared with 3D-crt or imrt, RapidArc showed better sparing of oars, especially duodenum, small bowel, and right kidney. Also, fewer acute grades 3 and 4 gastrointestinal toxicities were seen with RapidArc than with 3D-crt or imrt. A technique with better sparing of oars and better target dose distributions could result in decreased clinical toxicities during radiation treatment for lapcc. PMID:26966412

  12. Reliability analysis of common hazardous waste treatment processes

    SciTech Connect

    Waters, R.D.

    1993-05-01

    Five hazardous waste treatment processes are analyzed probabilistically using Monte Carlo simulation to elucidate the relationships between process safety factors and reliability levels. The treatment processes evaluated are packed tower aeration, reverse osmosis, activated sludge, upflow anaerobic sludge blanket, and activated carbon adsorption.

  13. Randomized Clinical Trial of Weekly vs. Triweekly Cisplatin-Based Chemotherapy Concurrent With Radiotherapy in the Treatment of Locally Advanced Cervical Cancer

    SciTech Connect

    Ryu, Sang-Young; Lee, Won-Moo; Kim, Kidong; Park, Sang-Il; Kim, Beob-Jong; Kim, Moon-Hong; Choi, Seok-Cheol; Cho, Chul-Koo; Nam, Byung-Ho; Lee, Eui-Don

    2011-11-15

    Purpose: To compare compliance, toxicity, and outcome of weekly and triweekly cisplatin administration concurrent with radiotherapy in locally advanced cervical cancer. Methods and Materials: In this open-label, randomized trial, 104 patients with histologically proven Stage IIB-IVA cervical cancer were randomly assigned by a computer-generated procedure to weekly (weekly cisplatin 40 mg/m{sup 2}, six cycles) and triweekly (cisplatin 75 mg/m{sup 2} every 3 weeks, three cycles) chemotherapy arms during concurrent radiotherapy. The difference of compliance and the toxicity profiles between the two arms were investigated, and the overall survival rate was analyzed after 5 years. Results: All patients tolerated both treatments very well, with a high completion rate of scheduled chemotherapy cycles. There was no statistically significant difference in compliance between the two arms (86.3% in the weekly arm, 92.5% in the triweekly arm, p > 0.05). Grade 3-4 neutropenia was more frequent in the weekly arm (39.2%) than in the triweekly arm (22.6%) (p = 0.03). The overall 5-year survival rate was significantly higher in the triweekly arm (88.7%) than in the weekly arm (66.5%) (hazard ratio 0.375; 95% confidence interval 0.154-0.914; p = 0.03). Conclusions: Triweekly cisplatin 75-mg/m{sup 2} chemotherapy concurrent with radiotherapy is more effective and feasible than the conventional weekly cisplatin 40-mg/m{sup 2} regimen and may be a strong candidate for the optimal cisplatin dose and dosing schedule in the treatment of locally advanced cervical cancer.

  14. WE-F-16A-06: Using 3D Printers to Create Complex Phantoms for Dose Verification, Quality Assurance, and Treatment Planning System Commissioning in Radiotherapy

    SciTech Connect

    Kassaee, A; Ding, X; McDonough, J; Reiche, M; Witztum, A; Teo, B

    2014-06-15

    Purpose: To use 3D printers to design and construct complex geometrical phantoms for commissioning treatment planning systems, dose calculation algorithms, quality assurance (QA), dose delivery, and patient dose verifications. Methods: In radiotherapy, complex geometrical phantoms are often required for dose verification, dose delivery and calculation algorithm validation. Presently, fabrication of customized phantoms is limited due to time, expense and challenges in machining of complex shapes. In this work, we designed and utilized 3D printers to fabricate two phantoms for QA purposes. One phantom includes hills and valleys (HV) for verification of intensity modulated radiotherapy for photons, and protons (IMRT and IMPT). The other phantom includes cylindrical cavities (CC) of various sizes for dose verification of inhomogeneities. We evaluated the HV phantoms for an IMPT beam, and the CC phantom to study various inhomogeneity configurations using photon, electron, and proton beams. Gafcromic ™ films were used to quantify the dose distributions delivered to the phantoms. Results: The HV phantom has dimensions of 12 cm × 12 cm and consists of one row and one column of five peaks with heights ranging from 2 to 5 cm. The CC phantom has a size 10 cm × 14 cm and includes 6 cylindrical cavities with length of 7.2 cm and diameters ranging from 0.6 to 1.2 cm. The IMPT evaluation using the HV phantom shows good agreement as compared to the dose distribution calculated with treatment planning system. The CC phantom also shows reasonable agreements for using different algorithms for each beam modalities. Conclusion: 3D printers with submillimiter resolutions are capable of printing complex phantoms for dose verification and QA in radiotherapy. As printing costs decrease and the technology becomes widely available, phantom design and construction will be readily available to any clinic for testing geometries that were not previously feasible.

  15. Treatment of trichlorophenol by catalytic oxidation process.

    PubMed

    Chu, W; Law, C K

    2003-05-01

    The oxidation of 2,4,6-trichlorophenol (TCP) by ferrous-catalyzed hydrogen peroxide was quantified and modeled in the study. TCP was effectively degraded by hydroxyl radicals that were generated by Fe(II)/H(2)O(2) in the oxidation process. The oxidation capacity (OC) of the process depends on the concentrations of oxidant (hydrogen peroxide) and oxidative catalyst (ferrous ion). Up to 99.6% of TCP removal can be achieved in the process, provided the doses of Fe(II) and H(2)O(2) are selected correctly. The OC of the process was successfully predicted through a kinetic approach in a two-stage model with some simple and measurable parameters, which makes the model useful for predicting, controlling and optimizing the catalyzed oxidation process in the degradation of TCP. PMID:12727243

  16. Preference for pharmaceutical formulation and treatment process attributes

    PubMed Central

    Stewart, Katie D; Johnston, Joseph A; Matza, Louis S; Curtis, Sarah E; Havel, Henry A; Sweetana, Stephanie A; Gelhorn, Heather L

    2016-01-01

    Purpose Pharmaceutical formulation and treatment process attributes, such as dose frequency and route of administration, can have an impact on quality of life, treatment adherence, and disease outcomes. The aim of this literature review was to examine studies on preferences for pharmaceutical treatment process attributes, focusing on research in diabetes, oncology, osteoporosis, and autoimmune disorders. Methods The literature search focused on identifying studies reporting preferences for attributes of the pharmaceutical treatment process. Studies were required to use formal quantitative preference assessment methods, such as utility valuation, conjoint analysis, or contingent valuation. Searches were conducted using Medline, EMBASE, Cochrane Library, Health Economic Evaluation Database, and National Health Service Economic Evaluation Database (January 1993–October 2013). Results A total of 42 studies met inclusion criteria: 19 diabetes, nine oncology, five osteoporosis, and nine autoimmune. Across these conditions, treatments associated with shorter treatment duration, less frequent administration, greater flexibility, and less invasive routes of administration were preferred over more burdensome or complex treatments. While efficacy and safety often had greater relative importance than treatment process, treatment process also had a quantifiable impact on preference. In some instances, particularly in diabetes and autoimmune disorders, treatment process attributes had greater relative importance than some or all efficacy and safety attributes. Some studies suggested that relative importance of treatment process depends on disease (eg, acute vs chronic) and patient (eg, injection experience) characteristics. Conclusion Despite heterogeneity in study methods and design, some general patterns of preference clearly emerged. Overall, the results of this review suggest that treatment process has a quantifiable impact on preference and willingness to pay for

  17. A qualitative study of cancer survivors' responses to information on the long-term and late effects of pelvic radiotherapy 1-11 years post treatment.

    PubMed

    Boulton, M; Adams, E; Horne, A; Durrant, L; Rose, P; Watson, E

    2015-09-01

    As more patients survive cancer for longer term, the long-term and late effects of treatments become increasingly important issues for cancer survivors and providing information to enable survivors to recognise and manage them becomes an increasingly pressing challenge for health care professionals. The aim of this study was to explore the experiences of cancer survivors regarding information given on potential long-term and late effects of pelvic radiotherapy. Semi-structured interviews were conducted with 28 cancer survivors who had had radiotherapy to the pelvic area for a range of cancers 1-11 years previously. Participants were recruited using maximum variation sampling from a larger questionnaire survey of patients treated at one hospital. Interviews were recorded, transcribed and analysed using Framework. Participants recognised the value of information to reassure and to inform action but also its potentially undesirable effects to frighten or raise anxieties about future problems and its inherent limitations in meeting their wider needs. They identified the timing, amount of information and context in which it was given as of particular importance. Information based on personal experience was also valued. These findings highlight the importance of appropriate, individualised information during treatment, at hospital discharge and subsequently in primary care. PMID:26202602

  18. Modeling the risk of secondary malignancies after radiotherapy.

    PubMed

    Schneider, Uwe

    2011-01-01

    underlying processes of the induction of carcinoma and sarcoma are not well known. Most uncertainties are related to the time patterns of cancer induction, the population specific dependencies and to the organ specific cancer induction rates. For radiotherapy treatment plan optimization these factors are irrelevant, as a treatment plan comparison is performed for a patient of specific age, sex, etc. If a treatment plan is compared relative to another one only the shape of the dose-response curve (the so called risk-equivalent dose) is of importance and errors can be minimized. PMID:24710304

  19. The Hybrid Treatment Process for treatment of mixed radioactive and hazardous wastes

    SciTech Connect

    Ross, W.A.; Kindle, C.H.

    1992-04-01

    This paper describes a new process for treating mixed hazardous and radioactive waste, commonly called mixed waste. The process is called the Hybrid Treatment Process (HTP), so named because it is built on the 20 years of experience with vitrification of wastes in melters, and the 12 years of experience with treatment of wastes by the in situ vitrification (ISV) process.

  20. Chest Wall Radiotherapy: Middle Ground for Treatment of Patients With One to Three Positive Lymph Nodes After Mastectomy

    SciTech Connect

    MacDonald, Shannon M.; Abi-Raad, Rita F.; Alm El-Din, Mohamed A.; Niemierko, Andrzej; Kobayashi, Wendy; McGrath, John J.; Goldberg, Saveli I.; Powell, Simon; Smith, Barbara; Taghian, Alphonse G.

    2009-12-01

    Purpose: To evaluate the outcomes for patients with Stage II breast cancer and one to three positive lymph nodes after mastectomy who were treated with observation or adjuvant radiotherapy to the chest wall (CW) with or without the regional lymphatics. Methods and Materials: We retrospectively analyzed 238 patients with Stage II breast cancer (one to three positive lymph nodes) treated with mastectomy at the Massachusetts General Hospital between 1990 and 2004. The estimates of locoregional recurrence (LRR), disease-free survival (DFS), and overall survival were analyzed according to the delivery of radiotherapy and multiple prognostic factors. Results: LRR and DFS were significantly improved by postmastectomy radiotherapy (PMRT), with a 5- and 10-year LRR rate without PMRT of 6% and 11%, respectively and, with PMRT, of 0% at both 5 and 10 years (p = .02). The 5- and 10-year DFS rate without PMRT was 85% and 75%, respectively, and, with PMRT, was 93% at both 5 and 10 years (p = .03). A similar benefit was found for patients treated with RT to the CW alone. The LRR, DFS, and overall survival rate for patients treated to the CW only was 0%, 96%, and 95% at 10 years, respectively. Conclusion: Our data suggest that adjuvant PMRT to the CW alone provides excellent disease control for patients with breast cancer <5 cm with one to three positive lymph nodes.

  1. Nitrous oxide emissions from wastewater treatment processes

    PubMed Central

    Law, Yingyu; Ye, Liu; Pan, Yuting; Yuan, Zhiguo

    2012-01-01

    Nitrous oxide (N2O) emissions from wastewater treatment plants vary substantially between plants, ranging from negligible to substantial (a few per cent of the total nitrogen load), probably because of different designs and operational conditions. In general, plants that achieve high levels of nitrogen removal emit less N2O, indicating that no compromise is required between high water quality and lower N2O emissions. N2O emissions primarily occur in aerated zones/compartments/periods owing to active stripping, and ammonia-oxidizing bacteria, rather than heterotrophic denitrifiers, are the main contributors. However, the detailed mechanisms remain to be fully elucidated, despite strong evidence suggesting that both nitrifier denitrification and the chemical breakdown of intermediates of hydroxylamine oxidation are probably involved. With increased understanding of the fundamental reactions responsible for N2O production in wastewater treatment systems and the conditions that stimulate their occurrence, reduction of N2O emissions from wastewater treatment systems through improved plant design and operation will be achieved in the near future. PMID:22451112

  2. Improved Clinical Outcomes With High-Dose Image Guided Radiotherapy Compared With Non-IGRT for the Treatment of Clinically Localized Prostate Cancer

    SciTech Conn