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Sample records for radiotherapy treatment room

  1. A new active method for the measurement of slow-neutron fluence in modern radiotherapy treatment rooms

    NASA Astrophysics Data System (ADS)

    Gómez, F.; Iglesias, A.; Sánchez Doblado, F.

    2010-02-01

    This work focuses on neutron monitoring at clinical linac facilities during high-energy modality radiotherapy treatments. Active in-room measurement of neutron fluence is a complex problem due to the pulsed nature of the fluence and the presence of high photon background, and only passive methods have been considered reliable until now. In this paper we present a new active method to perform real-time measurement of neutron production around a medical linac. The device readout is being investigated as an estimate of patient neutron dose exposure on each radiotherapy session. The new instrument was developed based on neutron interaction effects in microelectronic memory devices, in particular using neutron-sensitive SRAM devices. This paper is devoted to the description of the instrument and measurement techniques, presenting the results obtained together with their comparison and discussion. Measurements were performed in several standard clinical linac facilities, showing high reliability, being insensitive to the photon fluence and EM pulse present inside the radiotherapy room, and having detector readout statistical relative uncertainties of about 2% on measurement of neutron fluence produced by 1000 monitor units irradiation runs.

  2. 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.

  3. 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

  4. Radiotherapy in the treatment of vertebral hemangiomas

    SciTech Connect

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

    1985-02-01

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

  5. 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).

  6. Radiotherapy in the treatment of postoperative chylothorax

    PubMed Central

    2013-01-01

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

  7. Accuracy requirements in radiotherapy treatment planning.

    PubMed

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

    2013-06-01

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

  8. 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.

  9. 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.

  10. Mean dose to lymphocytes during radiotherapy treatments

    SciTech Connect

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

    1994-10-01

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

  11. Surgical management of combined intramedullary arteriovenous malformation and perimedullary arteriovenous fistula within the hybrid operating room after five years of performing focus fractionated radiotherapy: case report.

    PubMed

    Gekka, Masayuki; Seki, Toshitaka; Hida, Kazutoshi; Osanai, Toshiya; Houkin, Kiyohiro

    2014-01-01

    Perimedullary arteriovenous fistula (AVF) shunts occur on the spinal cord surface and can be treated surgically or by endovascular embolization. In contrast, the nidus of an intramedullary arteriovenous malformation (AVM) is located in the spinal cord and is difficult to treat surgically or by endovascular techniques. The benefits of radiotherapy for treating intramedullary AVM have been published, but are anecdotal and consist largely of case reports. We present a case of combined cervical intramedullary AVM and perimedullary AVF which received surgical treatment within a hybrid operating room (OR) after 5 years of focus fractionated radiotherapy. A 37-year-old male presented with stepwise worsening myelopathy. Magnetic resonance imaging and spinal angiography revealed intramedullary AVM and perimedullary AVF at the C3 to C5 levels. In order to reduce nidus size and blood flow, we first performed focal fractionated radiotherapy. Five years later, the lesion volume was reduced. Following this, direct surgery was performed by an anterior approach using corpectomy in the hybrid OR. The spinal cord was monitored by motor-evoked potential throughout the surgery. Complete obliteration of the fistulous connection was confirmed by intraoperative indocyanine green video-angiography and intraoperative angiography, preserving the anterior spinal artery. We conclude that surgical treatment following focal fractionated radiotherapy may become one strategy for patients who are initially deemed ineligible for endovascular embolization and surgical treatment. Furthermore, the hybrid OR enables safe and precise treatment for spinal vascular disorders in the fields of endovascular treatment and neurosurgery.

  12. 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.

  13. Development of real-time motion verification system using in-room optical images for respiratory-gated radiotherapy.

    PubMed

    Park, Yang-Kyun; Son, Tae-geun; Kim, Hwiyoung; Lee, Jaegi; Sung, Wonmo; Kim, Il Han; Lee, Kunwoo; Bang, Young-bong; Ye, Sung-Joon

    2013-09-06

    Phase-based respiratory-gated radiotherapy relies on the reproducibility of patient breathing during the treatment. To monitor the positional reproducibility of patient breathing against a 4D CT simulation, we developed a real-time motion verification system (RMVS) using an optical tracking technology. The system in the treatment room was integrated with a real-time position management system. To test the system, an anthropomorphic phantom that was mounted on a motion platform moved on a programmed breathing pattern and then underwent a 4D CT simulation with RPM. The phase-resolved anterior surface lines were extracted from the 4D CT data to constitute 4D reference lines. In the treatment room, three infrared reflective markers were attached on the superior, middle, and inferior parts of the phantom along with the body midline and then RMVS could track those markers using an optical camera system. The real-time phase information extracted from RPM was delivered to RMVS via in-house network software. Thus, the real-time anterior-posterior positions of the markers were simultaneously compared with the 4D reference lines. The technical feasibility of RMVS was evaluated by repeating the above procedure under several scenarios such as ideal case (with identical motion parameters between simulation and treatment), cycle change, baseline shift, displacement change, and breathing type changes (abdominal or chest breathing). The system capability for operating under irregular breathing was also investigated using real patient data. The evaluation results showed that RMVS has a competence to detect phase-matching errors between patient's motion during the treatment and 4D CT simulation. Thus, we concluded that RMVS could be used as an online quality assurance tool for phase-based gating treatments.

  14. 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.

  15. Treatment of ameloblastoma and ameloblastic carcinoma with radiotherapy.

    PubMed

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

    2016-10-01

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

  16. 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.

  17. 14. Water treatment plant interior view of chlorination room. View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Water treatment plant interior view of chlorination room. View to N - Fort Benton Water Treatment Plant, Filtration Plant, Lots 9-13 of Block 7, Fort Benton Original Townsite at Missouri River, Fort Benton, Chouteau County, MT

  18. 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

  19. 18. PLAIN OFFICE; SHOWS WOODWORK AND WALL TREATMENT. ROOM 2662, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. PLAIN OFFICE; SHOWS WOODWORK AND WALL TREATMENT. ROOM 2662, SECOND FLOOR, SOUTH SIDE. - Hughes Aircraft Company, Processing & Electronics Building, 6775 Centinela Avenue, Los Angeles, Los Angeles County, CA

  20. 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.

  1. Intensity-modulated radiotherapy in the treatment of prostate cancer.

    PubMed

    Bauman, G; Rumble, R B; Chen, J; Loblaw, A; Warde, P

    2012-09-01

    Three-dimensional conformal radiotherapy (3DCRT) as the primary treatment for prostate cancer has improved outcomes compared with conventional radiotherapy, but with an associated increase in toxicity due to radiation effects on the bladder and rectum. Intensity-modulated radiotherapy (IMRT) is a newer method of radiotherapy that uses intensity-modulated beams that can provide multiple intensity levels for any single beam direction and any single source position allowing concave dose distributions and dose gradients with narrower margins than those possible using conventional methods. IMRT is ideal for treating complex treatment volumes and avoiding close proximity organs at risk that may be dose limiting and provides increased tumour control through an escalated dose and reduces normal tissue complications through organ at risk sparing. Given the potential advantages of IMRT and the availability of IMRT-enabled treatment planning systems and linear accelerators, IMRT has been introduced in a number of disease sites, including prostate cancer. This systematic review examined the evidence for IMRT in the treatment of prostate cancer in order to quantify the potential benefits of this new technology and to make recommendations for radiation treatment programmes considering adopting this technique. The findings were in favour of recommending IMRT over 3DCRT in the radical treatment of localised prostate cancer where doses greater than 70 Gy are required, based on a review of 11 published reports including 4559 patients. There were insufficient data to recommend IMRT over 3DCRT in the postoperative setting. Future research should examine image-guided IMRT in the post-prostatectomy setting, with altered fractionation, and in combination with hormone and chemotherapy.

  2. "Noninvasive" oral treatment of asthma in the emergency room.

    PubMed

    Aelony, Y

    1985-06-01

    One hundred forty consecutive patients with acute asthmatic episodes presenting to the emergency room were studied prospectively to assess the efficacy of oral therapy. After the emergency room staff was oriented to the pharmacologic action of hydroalcoholic elixir of theophylline, oral terbutaline, and a metered-dose hand-held nebulizer (metaproterenol), use of oral therapy as initial therapy rose from 12 percent to 76 percent (p = 0.005). More than half of these patients were discharged without receiving any of the traditional more invasive therapies of subcutaneous epinephrine, intravenous hydrating fluids with aminophylline, and machine-delivered sympathomimetic aerosols. Oral therapy did not substantially alter the total time spent in the emergency room. Only 4 percent treated with oral therapy required further treatment in the emergency room within 48 hours; 2 percent vomited after treatment. Oral therapy is safe and effective for most asthmatic patients presenting to the emergency room, as they generally are undermedicated with regard to theophyllines and sympathomimetic drugs. Use of oral therapy in the emergency room is a potent tool for educating asthmatic patients in the use of medication available for home use. The patients who require emergency room treatment despite being well-medicated at home (a small minority) need a higher level of care including intermittent positive-pressure breathing, corticosteroids, and often hospitalization.

  3. Intensity-modulated radiotherapy in the treatment of gynaecological cancers.

    PubMed

    D'Souza, D P; Rumble, R B; Fyles, A; Yaremko, B; Warde, P

    2012-09-01

    Intensity-modulated radiotherapy (IMRT) is a newer method of radiotherapy that uses intensity-modulated beams that can provide multiple intensity levels for any single beam direction and any single source position allowing concave dose distributions and dose gradients with narrower margins than those possible using conventional methods. IMRT is ideal for treating complex treatment volumes and avoiding close proximity organs at risk that may be dose limiting and provides increased tumour control through an escalated dose and reduces normal tissue complications through organ at risk sparing. Given the potential advantages of IMRT and the availability of IMRT-enabled treatment planning systems and linear accelerators, IMRT has been introduced in a number of disease sites. This systematic review examined the evidence for IMRT in the treatment of gynaecological cancers to quantify the potential benefits of this new technology and to make recommendations for radiation treatment programmes considering adopting this technique. Findings were based on a review of four cohort studies, one of which was prospective, including a total of 619 patients. If reducing acute and chronic toxicity are the main outcomes of interest, then IMRT may be considered over three-dimensional conformal radiotherapy for women with gynaecological cancers; if disease-related outcomes are the main outcomes of interest, there are insufficient data to recommend IMRT over three-dimensional conformal radiotherapy. Future research should focus on prospective multicentre studies reporting on both acute and chronic toxicity as well as survival and recurrence. Dose escalation studies should be carried out to investigate the effect of higher doses on disease.

  4. 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

  5. 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.

  6. Results of treatment of uterine cervix cancer by radiotherapy.

    PubMed

    Sinistrero, G; Sismondi, P; Zola, P

    1988-12-01

    The results of treatment of uterine cervix cancer by radiotherapy alone in 259 patients in the period January 1973 to December 1984 are reported. They are analyzed according to patients age, stage, tumor volume, extent of parametrial infiltration, hydronephrosis and nodal status. It is shown that age, tumor volume, extent of parametrial invasion and nodal metastases are the main prognostic factors. Analysis of pelvic failures shows that external radiotherapy followed by curietherapy seems to be the best method for patients with T2b and T3b tumors of small volume (less than 60 mm in diameter), particularly when parametrial infiltration is limited. Patients with T2b tumors of large volume (barrel shaped) seem to need a more aggressive approach, and a higher number of complications are therefore expected. Patients with T3b and massive parametrial infiltration, with T4 and nodal metastases need new and different approaches, possibly including adjuvant chemotherapy.

  7. 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

  8. 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

  9. 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.

  10. 20. VIEW OF WASTE TREATMENT CONTROL ROOM IN BUILDING 374. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. VIEW OF WASTE TREATMENT CONTROL ROOM IN BUILDING 374. THE BUILDING 371/374 COMPLEX WAS DESIGNED TO EMPHASIZE AUTOMATICALLY CONTROLLED, REMOTELY OPERATED PROCESSES. (1/80) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  11. 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

  12. Production of neutrons in laminated barriers of radiotherapy rooms: comparison between the analytical methodology and Monte Carlo simulations.

    PubMed

    Rezende, Gabriel Fonseca da Silva; Da Rosa, Luiz Antonio Ribeiro; Facure, Alessandro

    2014-11-08

    The necessity to build or adapt radiotherapy rooms in reduced areas leads to the search for unconventional solutions for shielding projects. In most cases, adding metals to the primary barriers is the best alternative to shield rooms properly. However, when photons with energies equal or higher than 10 MV interact with high atomic number nuclei, neutrons are ejected and may result in a radioprotec- tion problem for both outside and inside the room. Currently, the most widely used mathematical model to estimate the neutron dose equivalents, beyond the barriers composed by concrete and metal, is applicable only in very specific conditions. Moreover, a validation work of this model had not yet been performed. In this work, the Monte Carlo code MCNPX was used to check the validity of the aforementioned mathematical model for cases of primary barriers containing steel or lead sheets, considering the existence of linear accelerators of 15 or 18 MV. The results of the study showed that over 80% of the values obtained by computational simulations revealed deviations above a factor of 2, when compared to the analytical formula. This led to the conclusion that the McGinley method cannot be considered an adequate mathematical model to describe the mentioned physical phenomenon. 

  13. [Patient positioning using in-room kV CT for image-guided radiotherapy (IGRT) of prostate cancer].

    PubMed

    Kliton, Jorgo; Agoston, Péter; Major, Tibor; Polgár, Csaba

    2012-09-01

    automatic and manual image registrations were 0.31 cm and 0.26 cm in LAT, 0.27 cm and 0.27 cm in LONG and 0.24 cm and 0.33 cm in VERT directions, respectively. In case of manual image co-registration, the required PTV to CTV margins to cover at least 95% of the CTVs with at least 95% percent of the prescribed dose were calculated to 0.93 cm in LAT, 0.65 cm in LONG, and 0.89 cm in VERT directions. Patients set up can be verified with manual image co-registration based on soft tissues around the prostate using a kV CT-on-rails system installed in the treatment room. The difference between automatic and manual image co-registration was significant in LAT direction. A PTV to CTV margin <1 cm seems to be appropriate to cover the CTVs in image-guided prostate radiotherapy. These findings support our recent clinical protocol.

  14. Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique

    PubMed Central

    Brodin, N. Patrik; Munck af Rosenschöld, Per; Blomstrand, Malin; Kiil-Berthlesen, Anne; Hollensen, Christian; Vogelius, Ivan R.; Lannering, Birgitta; Bentzen, Søren M.; Björk-Eriksson, Thomas

    2014-01-01

    Background We investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy. Methods We included 17 pediatric medulloblastoma patients to represent the variability in tumor location relative to the hippocampal region. Treatment plans were generated using 3D conformal radiotherapy, hippocampal sparing intensity-modulated radiotherapy, and spot-scanned proton therapy, using 3 different treatment margins for the conformal tumor boost. Neurocognitive impairment risk was estimated based on dose-response models from pediatric CNS malignancy survivors and compared among different margins and treatment techniques. Results Mean hippocampal dose and corresponding risk of cognitive impairment were decreased with decreasing treatment margins (P < .05). The largest risk reduction, however, was seen when applying hippocampal sparing proton therapy—the estimated risk of impaired task efficiency (95% confidence interval) was 92% (66%–98%), 81% (51%–95%), and 50% (30%–70%) for 3D conformal radiotherapy, intensity-modulated radiotherapy, and proton therapy, respectively, for the smallest boost margin and 98% (78%–100%), 90% (60%–98%), and 70% (39%–90%) if boosting the whole posterior fossa. Also, the distance between the closest point of the planning target volume and the center of the hippocampus can be used to predict mean hippocampal dose for a given treatment technique. Conclusions We estimate a considerable clinical benefit of hippocampal sparing radiotherapy. In choosing treatment margins, the tradeoff between margin size and risk of neurocognitive impairment quantified here should be considered. PMID:24327585

  15. 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.

  16. 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

  17. What is changing in radiotherapy for the treatment of locally advanced nonsmall cell lung cancer patients? A review.

    PubMed

    Giaj-Levra, Niccoló; Ricchetti, Francesco; Alongi, Filippo

    2016-01-01

    Radiotherapy treatment continues to have a relevant impact in the treatment of nonsmall cell cancer (NSCLC). Use of concurrent chemotherapy and radiotherapy is considered the gold standard in the treatment of locally advanced NSCLC but clinical outcomes are not satisfactory. Introduction of new radiotherapy technology and chemotherapy regimens are under investigation in this setting with the goal to improve unsatisfactory results. We report how radiotherapy is changing in the treatment of locally advanced NSCLC.

  18. Neutron distribution and induced activity inside a Linac treatment room.

    PubMed

    Juste, B; Miró, R; Verdú, G; Díez, S; Campayo, J M

    2015-01-01

    Induced radioactivity and photoneutron contamination inside a radiation therapy bunker of a medical linear accelerator (Linac) is investigated in this work. The Linac studied is an Elekta Precise electron accelerator which maximum treatment photon energy is 15 MeV. This energy exceeds the photonuclear reaction threshold (around 7 MeV for high atomic number metals). The Monte Carlo code MCNP6 has been used for quantifying the neutron contamination inside the treatment room for different gantry rotation configuration. Walls activation processes have also been simulated. The approach described in this paper is useful to prevent the overexposure of patients and medical staff. PMID:26737878

  19. 33 CFR 149.685 - May a medical treatment room be used for other purposes?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... other purposes? A medical treatment room may be used as a sleeping space if the room meets the requirements of this subpart for both medical treatment rooms and sleeping spaces. It may also be used as an office. However, when used for medical purposes, the room may not be used as a sleeping space or...

  20. 33 CFR 149.685 - May a medical treatment room be used for other purposes?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... other purposes? A medical treatment room may be used as a sleeping space if the room meets the requirements of this subpart for both medical treatment rooms and sleeping spaces. It may also be used as an office. However, when used for medical purposes, the room may not be used as a sleeping space or...

  1. 33 CFR 149.685 - May a medical treatment room be used for other purposes?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... other purposes? A medical treatment room may be used as a sleeping space if the room meets the requirements of this subpart for both medical treatment rooms and sleeping spaces. It may also be used as an office. However, when used for medical purposes, the room may not be used as a sleeping space or...

  2. 33 CFR 149.685 - May a medical treatment room be used for other purposes?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... other purposes? A medical treatment room may be used as a sleeping space if the room meets the requirements of this subpart for both medical treatment rooms and sleeping spaces. It may also be used as an office. However, when used for medical purposes, the room may not be used as a sleeping space or...

  3. 33 CFR 149.685 - May a medical treatment room be used for other purposes?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... other purposes? A medical treatment room may be used as a sleeping space if the room meets the requirements of this subpart for both medical treatment rooms and sleeping spaces. It may also be used as an office. However, when used for medical purposes, the room may not be used as a sleeping space or...

  4. 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.

  5. 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.

  6. [Combined radiotherapy and chemotherapy for the treatment of esophageal cancer].

    PubMed

    Mishina, H; Okuyama, S; Lim, I; Yamagata, R; Taima, T; Ogasawara, T; Yamamoto, K

    1983-05-01

    Eight patients with esophageal cancer were treated by a new treatment schedule consisting of low dose irradiation, crescendo cisplatin and bleomycin polyacrylate pasta. As monitored endoscopically, therapeutic responses were satisfactory: seven out of 8 patients have survived for a range of 3 to 20 months and still active at work or cancer-free. However, one patient suffered from a second malignancy of adenocarcinoma of the upper esophagus different from the initial squamous cell carcinoma at the lower esophagus which had successfully been treated 3 months before. The present therapeutic design aims at treatment of lymphatic spreads in the adjacent structures as well as the original tumor in the esophagus and submucosal invasions. It is basically a consecutive, multimodal integration of selective concentration of therapeutic effects (extensive radiotherapy, topical application of bleomycin polyacrylate pasta, lymphatic chasing with colloidal bleomycin, and spatial concentration of cisplatin as the result of radiation-induced inflammation), perpetuation of the repairable DNA damage, and biological amplifications (protection against esophageal perforation with polyacrylate coating, and specific cancer cell recruitment). Application of the present therapeutic design is being expanded to the treatment of cancer of other specific sites such as the head and neck tumors and rectal cancer with undeniable prospects.

  7. [Feasibility of Automatic Treatment Planning in Intensity-modulated Radiotherapy of Nasopharyngeal Carcinoma].

    PubMed

    He, Yinbo; Zhang, Longbin; Xiao, Jianghong; Duan, Baofeng

    2015-12-01

    Intensity-modulated radiotherapy planning for nasopharyngeal carcinoma is very complex. The quality of plan is often closely linked to the experience of the treatment planner. In this study, 10 nasopharyngeal carcinoma patients at different stages were enrolled. Based on the scripting of Pinnacle 9. 2 treatment planning system, the computer program was used to set the basic parameters and objective parameters of the plans. At last, the nasopharyngeal carcinoma intensity-modulated radiotherapy plans were completed automatically. Then, the automatical and manual intensity-modulated radiotherapy plans were statistically compared and clinically evaluated. The results showed that there were no significant differences between those two kinds of plans with respect to the dosimetry parameters of most targets and organs at risk. The automatical nasopharyngeal carcinoma intensity-modulated radiotherapy plans can meet the requirements of clinical radiotherapy, significantly reduce planning time, and avoid the influence of human factors such as lack of experience to the quality of plan. PMID:27079103

  8. Monitor Unit Checking in Heterogeneous Stereotactic Body Radiotherapy Treatment Planning

    SciTech Connect

    Higgins, Patrick D.; Adolfson, Troy; Cho, L. Chinsoo; Saxena, Rishik

    2011-10-01

    Treatment of lung cancer using very-high-dose fractionation in small fields requires well-tested dose modeling, a method for density-averaging compound targets constructed from different parts of the breathing cycle, and monitor unit verification of the heterogeneity-corrected treatment plans. The quality and safety of each procedure are dependent on these factors. We have evaluated the dosimetry of our first 26 stereotactic body radiotherapy (SBRT) patients, including 260 treatment fields, planned with the Pinnacle treatment planning system. All targets were combined from full expiration and inspiration computed tomography scans and planned on the normal respiration scan with 6-MV photons. Combined GTVs (cGTVs) have been density-averaged in different ways for comparison of the effect on total monitor units. In addition, we have compared planned monitor units against hand calculations using 2 classic 1D correction methods: (1) effective attenuation and (2) ratio of Tissue-Maximum Ratios (TMRs) to determine the range of efficacy of simple verification methods over difficult-to-perform measurements. Different methods of density averaging for combined targets have been found to have minimal impact on total dose as evidenced by the range of total monitor units generated for each method. Nondensity-corrected treatment plans for the same fields were found to require about 8% more monitor units on average. Hand calculations, using the effective attenuation method were found to agree with Pinnacle calculations for nonproblematic fields to within {+-}10% for >95% of the fields tested. The ratio of TMRs method was found to be unacceptable. Reasonable choices for density-averaging of cGTVs using full inspiration/expiration scans should not strongly affect the planning dose. Verification of planned monitor units, as a check for problematic fields, can be done for 6-MV fields with simple 1D effective attenuation-corrected hand calculations.

  9. 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.

  10. Partial differential equations-based segmentation for radiotherapy treatment planning.

    PubMed

    Gibou, Frederic; Levy, Doron; Cardenas, Carlos; Liu, Pingyu; Boyer, Arthur

    2005-04-01

    The purpose of this study is to develop automatic algorithms for the segmentation phase of radiotherapy treatment planning. We develop new image processing techniques that are based on solving a partial diferential equation for the evolution of the curve that identifies the segmented organ. The velocity function is based on the piecewise Mumford-Shah functional. Our method incorporates information about the target organ into classical segmentation algorithms. This information, which is given in terms of a three- dimensional wireframe representation of the organ, serves as an initial guess for the segmentation algorithm. We check the performance of the new algorithm on eight data sets of three diferent organs: rectum, bladder, and kidney. The results of the automatic segmentation were compared with a manual seg- mentation of each data set by radiation oncology faculty and residents. The quality of the automatic segmentation was measured with the k-statistics", and with a count of over- and undersegmented frames, and was shown in most cases to be very close to the manual segmentation of the same data. A typical segmentation of an organ with sixty slices takes less than ten seconds on a Pentium IV laptop.

  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. Radiometric survey of teletherapy treatment rooms in Brazil.

    PubMed

    de Paiva, E; Giannoni, R A; Velasco, A F; Brito, R R A; Dovales, A C M; de Sá, L V; da Rosa, L A R

    2010-03-01

    The Brazilian national regulatory authority, National Commission of Nuclear Energy, requires that dose rates in the vicinity of teletherapy treatment rooms do not exceed the permissible limits for workers as well as members of the public, depending on the place considered. At the end of 2005, the Brazilian national regulatory authority reduced the permissible dose limit for controlled areas from 1000 to 400 microSv week(-1). Therefore, the aim of this work is to verify the adequacy of structural shielding to this new limit for telecobalt units that had their sources changed and clinic linear accelerators (ALs) installed before the end of 2005. Considering the ALs, measurements of dose rates in controlled areas did not exceed the new permissible limit, excepting for a single case. In the case of (60)Co units, a similar situation is observed for controlled areas, although several non-conformities to the limit of uncontrolled area could be observed. PMID:19926674

  13. 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.

  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. 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

  16. 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

  17. 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.

  18. Radiotherapy in the treatment of Graves ophthalmopathy—to do it or not?

    PubMed Central

    2009-01-01

    To the objective of this study is to evaluate the role and toxicity of radiotherapy in the treatment of Graves ophthalmopathy. In the years 2000–2003, 121 patients with malignant exophthalmos were treated with radiotherapy of the retrobulbar area to the total dose of 20 Gy in ten fractions with a 6 MeV photon beam. The treatment was performed by the team of the Clinic of Oncology of the Jagiellonian University Medical College in Cracow. The radiotherapy was preceded by intravenous steroid therapy: methylprednisolone acetate administered at the dose of 2 g/week for four consecutive weeks. The highest efficacy, expressed as improvement of all ocular symptoms, was observed for the combined treatment. Female and non-diabetic patients responded positively to the combined treatment. Radiotherapy combined with steroid therapy in the treatment of Graves ophthalmopathy seems to be an effective treatment for strictly defined indications. In the treatment of Graves–Basedow disease, radiotherapy is a well-tolerated treatment modality. Diabetes is a factor that worsens prognosis in Graves ophthalmopathy and female sex is a favourable factor for this condition. PMID:20835395

  19. Ambient neutron dose equivalent outside concrete vault rooms for 15 and 18 MV radiotherapy accelerators.

    PubMed

    Martínez-Ovalle, S A; Barquero, R; Gómez-Ros, J M; Lallena, A M

    2012-03-01

    In this work, the ambient dose equivalent, H*(10), due to neutrons outside three bunkers that house a 15- and a 18-MV Varian Clinac 2100C/D and a 15-MV Elekta Inor clinical linacs, has been calculated. The Monte Carlo code MCNPX (v. 2.5) has been used to simulate the neutron production and transport. The complete geometries including linacs and full installations have been built up according to the specifications of the manufacturers and the planes provided by the corresponding medical physical services of the hospitals where the three linacs operate. Two of these installations, those lodging the Varian linacs, have an entrance door to the bunker while the other one does not, although it has a maze with two bends. Various treatment orientations were simulated in order to establish plausible annual equivalent doses. Specifically anterior-posterior, posterior-anterior, left lateral, right lateral orientations and an additional one with the gantry rotated 30° have been studied. Significant dose rates have been found only behind the walls and the door of the bunker, near the entrance and the console, with a maximum of 12 µSv h(-1). Dose rates per year have been calculated assuming a conservative workload for the three facilities. The higher dose rates in the corresponding control areas were 799 µSv y(-1), in the case of the facility which operates the 15-MV Clinac, 159 µSv y(-1), for that with the 15-MV Elekta, and 21 µSv y(-1) for the facility housing the 18-MV Varian. A comparison with measurements performed in similar installations has been carried out and a reasonable agreement has been found. The results obtained indicate that the neutron contamination does not increase the doses above the legal limits and does not produce a significant enhancement of the dose equivalent calculated. When doses are below the detection limits provided by the measuring devices available today, MCNPX simulation provides an useful method to evaluate neutron dose equivalents based

  20. SU-E-T-387: Achieving Optimal Patient Setup Imaging and Treatment Workflow Configurations in Multi-Room Proton Centers

    SciTech Connect

    Zhang, H; Prado, K; Langen, K; Yi, B; Mehta, M; Regine, W; D'Souza, W

    2014-06-01

    Purpose: To simulate patient flow in proton treatment center under uncertainty and to explore the feasibility of treatment preparation rooms to improve patient throughput and cyclotron utilization. Methods: Three center layout scenarios were modeled: (S1: In-Tx room imaging) patient setup and imaging (planar/volumetric) performed in treatment room, (S2: Patient setup in preparation room) each treatment room was assigned with preparation room(s) that was equipped with lasers only for patient setup and gross patient alignment, and (S3: Patient setup and imaging in preparation room) preparation room(s) was equipped with laser and volumetric imaging for patient setup, gross and fine patient alignment. A 'snap' imaging was performed in treatment room. For each scenario, the number of treatment rooms and the number of preparation rooms serving each treatment room were varied. We examined our results (average of 100 16-hour (two shifts) working days) by evaluating patient throughput and cyclotron utilization. Results: When the number of treatment rooms increased ([from, to]) [1, 5], daily patient throughput increased [32, 161], [29, 184] and [27, 184] and cyclotron utilization increased [13%, 85%], [12%, 98%], and [11%, 98%] for scenarios S1, S2 and S3 respectively. However, both measures plateaued after 4 rooms. With the preparation rooms, the throughput and the cyclotron utilization increased by 14% and 15%, respectively. Three preparation rooms were optimal to serve 1-3 treatment rooms and two preparation rooms were optimal to serve 4 or 5 treatment rooms. Conclusion: Patient preparation rooms for patient setup may increase throughput and decrease the need for additional treatment rooms (cost effective). Optimal number of preparation rooms serving each gantry room varies as a function of treatment rooms and patient setup scenarios. A 5th treatment room may not be justified by throughput or utilization.

  1. 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

  2. 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.

  3. 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

  4. 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

  5. Understanding the Treatment Strategies of Intracranial Germ Cell Tumors: Focusing on Radiotherapy

    PubMed Central

    Park, Jeonghoon

    2015-01-01

    Intracranial germ cell tumors (ICGCT) occur in 2-11% of children with brain tumors between 0-19 years of age. For treatment of germinoma, relatively low radiation doses with or without chemotherapy show excellent 10 year survival rate of 80-100%. Past studies showed that neoadjuvant chemotherapy combined with focal radiotherapy resulted in unacceptably high rates of periventricular tumor recurrence. The use of generous radiation volume which covers the whole ventricular space with later boost treatment to primary site is considered as standard treatment of intracranial germinomas. For non-germinomatous germ cell tumors (NGGCT), 10-year overall survival rate is still much inferior than that of intracranial germinoma despite intensive chemotherapy and high-dose radiotherapy. Craniospinal radiotherapy combined with cisplatin-based chemotherapy provides the best treatment outcome for NGGCT; 60-70% of overall survival rate. There is a debate on the surgical role whether surgery can contribute to improved treatment outcome of NGGCT when added to combined chemoradiotherapy. Because higher dose of radiotherapy is required for treatment of NGGCT than for germinoma, it is tested whether whole ventricular irradiation can replace craniospinal irradiation in intermediate risk group of NGGCT to minimize radiation-related late toxicity in the recent studies. To minimize the treatment-related neural deficit and late sequelae while maintaining long-term survival rate of ICGCT patients, optimized administration of chemotherapy and radiotherapy should be selected. Use of technically upgraded radiotherapy modalities such as intensity-modulated radiotherapy or proton beam therapy is expected to bring an improved neurocognitive outcome with longitudinal assessment of the patients. PMID:26113957

  6. Treatment of pediatric migraine in the emergency room.

    PubMed

    Gelfand, Amy A; Goadsby, Peter J

    2012-10-01

    Migraine constitutes a relatively common reason for pediatric emergency room visits. Given the paucity of randomized trials involving pediatric migraineurs in the emergency department setting compared with adults, recommendations for managing these children are largely extrapolated from adult migraine emergency room studies and trials involving outpatient home pediatric migraine therapy. We review current knowledge about pediatric migraineurs presenting at the emergency room and their management, and summarize the best evidence available to guide clinical decision-making.

  7. The use of strontium-90 Beta radiotherapy as adjuvant treatment for conjunctival melanoma.

    PubMed

    Cohen, Victoria M L; Papastefanou, Vasilios P; Liu, S; Stoker, Ian; Hungerford, John L

    2013-01-01

    Background/Aims. To report the safety and efficacy of strontium (Sr(90)) beta radiotherapy as adjuvant treatment for conjunctival melanoma. Methods. A retrospective cohort study was undertaken from 1999 to 2007 of all patients who underwent Sr(90) beta radiotherapy for incompletely excised conjunctival melanoma. Failure of treatment was defined as recurrence of a conjunctival melanoma at the same location following beta radiotherapy. Results. Twenty patients underwent Sr(90) beta radiotherapy for incompletely excised conjunctival melanoma. Median follow-up interval was 59 months (8-152). All patients had conjunctival melanoma involving the bulbar conjunctiva. Underlying diagnoses included PAM with atypia in 60% (12 of 20), PAM without atypia in 15% (3 of 20), and de novo conjunctival melanoma in 25% (5 of 20). Following Sr(90) beta radiotherapy, in 90% (18 out of 20) local control was achieved and visual acuity was not affected in any patient. Three patients (15%) had dry eye symptoms, episcleritis, and descemetcoele, respectively. No cataract or secondary glaucoma was reported. Conclusions. Sr(90) treatment is a very effective adjuvant treatment after excisional biopsy and cryotherapy for conjunctival melanoma with a local success rate of 90%. The treatment is not associated with significant side effects and visual acuity is not affected.

  8. Oesophagus side effects related to the treatment of oesophageal cancer or radiotherapy of other thoracic malignancies.

    PubMed

    Adebahr, Sonja; Schimek-Jasch, Tanja; Nestle, Ursula; Brunner, Thomas B

    2016-08-01

    The oesophagus as a serial organ located in the central chest is frequent subject to "incidental" dose application in radiotherapy for several thoracic malignancies including oesophageal cancer itself. Especially due to the radiosensitive mucosa severe radiotherapy induced sequelae can occur, acute oesophagitis and strictures as late toxicity being the most frequent side-effects. In this review we focus on oesophageal side effects derived from treatment of gastrointestinal cancer and secondly provide an overview on oesophageal toxicity from conventional and stereotactic fractionated radiotherapy to the thoracic area in general. Available data on pathogenesis, frequency, onset, and severity of oesophageal side effects are summarized. Whereas for conventional radiotherapy the associations of applied doses to certain volumes of the oesophagus are well described, the tolerance dose to the mediastinal structures for hypofractionated therapy is unknown. The review provides available attempts to predict the risk of oesophageal side effects from dosimetric parameters of SBRT. PMID:27644905

  9. A FORTRAN program for the optimization of radiotherapy treatment planning using the complication probability factor (CPF).

    PubMed

    Wolbarst, A B; Sternick, E S; Curran, B H; Kosinski, R J; Dritschilo, A

    1980-04-01

    The complication probability factor (CPF) is an objective function, based directly on radiobiological principles and clinical data, for the optimization of radiotherapy treatment planning; it measures the likelihood that a given radiation 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 that treatment plan which delivers an acceptable tumoricidal dose, yet minimizes the CPF as averaged over the total volume of healthy tissue irradiated. The CPF FORTRAN program, run on a PDP 11/55 in conjunction with a commercially available radiotherapy treatment planning package, is described in detail.

  10. 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

  11. Multimodality image integration for radiotherapy treatment: an easy approach

    NASA Astrophysics Data System (ADS)

    Santos, Andres; Pascau, Javier; Desco, Manuel; Santos, Juan A.; Calvo, Felipe A.; Benito, Carlos; Garcia-Barreno, Rafael

    2001-05-01

    The interest of using combined MR and CT information for radiotherapy planning is well documented. However, many planning workstations do not allow to use MR images, nor import predefined contours. This paper presents a new simple approach for transferring segmentation results from MRI to a CT image that will be used for radiotherapy planning, using the same original CT format. CT and MRI images of the same anatomical area are registered using mutual information (MI) algorithm. Targets and organs at risk are segmented by the physician on the MR image, where their contours are easy to track. A locally developed software running on PC is used for this step, with several facilities for the segmentation process. The result is transferred onto the CT by slightly modifying up and down the original Hounsfield values of some points of the contour. This is enough to visualize the contour on the CT, but does not affect dose calculations. The CT is then stored using the original file format of the radiotherapy planning workstation, where the technician uses the segmented contour to design the correct beam positioning. The described method has been tested in five patients. Simulations and patient results show that the dose distribution is not affected by the small modification of pixels of the CT image, while the segmented structures can be tracked in the radiotherapy planning workstation-using adequate window/level settings. The presence of the physician is not requires at the planning workstation, and he/she can perform the segmentation process using his/her own PC. This new approach makes it possible to take advantage from the anatomical information present on the MRI and to transfer the segmentation to the CT used for planning, even when the planning workstation does not allow to import external contours. The physician can draw the limits of the target and areas at risk off-line, thus separating in time the segmentation and planning tasks and increasing the efficiency.

  12. [Clinical study on effect of combined treatment of fuchunpian with radiotherapy on nasopharyngeal carcinoma].

    PubMed

    Han, J Q; Chen, Y T; Man, Y Y

    1995-12-01

    The study based on the clinical prospective trial of 60 cases of nasopharyngeal carcinoma treated with combined treatment of radiotherapy and Fuchunpian in our hospital from September, 1988 to January, 1990. Results of clinical data of 5 years follow-up showed that Fuchunpian not only couldn't enhance the radiosensitivity of patients, but also increase the blood metastatic potency, the metastatic rate of patients treated with Fuchunpian (36.7%) was 2.67 times higher than that without it (10.0%). Therefore, it was considered that use Fuchunpian as a routine either administrated alone or combined with radiotherapy in treatment of nasopharyngeal carcinoma is not suitable. PMID:8732135

  13. Nonrigid Image Registration for Head and Neck Cancer Radiotherapy Treatment Planning With PET/CT

    SciTech Connect

    Ireland, Rob H. . E-mail: r.ireland@sheffield.ac.uk; Dyker, Karen E.; Barber, David C.; Wood, Steven M.; Hanney, Michael B.; Tindale, Wendy B.; Woodhouse, Neil; Hoggard, Nigel; Conway, John; Robinson, Martin H.

    2007-07-01

    Purpose: Head and neck radiotherapy planning with positron emission tomography/computed tomography (PET/CT) requires the images to be reliably registered with treatment planning CT. Acquiring PET/CT in treatment position is problematic, and in practice for some patients it may be beneficial to use diagnostic PET/CT for radiotherapy planning. Therefore, the aim of this study was first to quantify the image registration accuracy of PET/CT to radiotherapy CT and, second, to assess whether PET/CT acquired in diagnostic position can be registered to planning CT. Methods and Materials: Positron emission tomography/CT acquired in diagnostic and treatment position for five patients with head and neck cancer was registered to radiotherapy planning CT using both rigid and nonrigid image registration. The root mean squared error for each method was calculated from a set of anatomic landmarks marked by four independent observers. Results: Nonrigid and rigid registration errors for treatment position PET/CT to planning CT were 2.77 {+-} 0.80 mm and 4.96 {+-} 2.38 mm, respectively, p = 0.001. Applying the nonrigid registration to diagnostic position PET/CT produced a more accurate match to the planning CT than rigid registration of treatment position PET/CT (3.20 {+-} 1.22 mm and 4.96 {+-} 2.38 mm, respectively, p = 0.012). Conclusions: Nonrigid registration provides a more accurate registration of head and neck PET/CT to treatment planning CT than rigid registration. In addition, nonrigid registration of PET/CT acquired with patients in a standardized, diagnostic position can provide images registered to planning CT with greater accuracy than a rigid registration of PET/CT images acquired in treatment position. This may allow greater flexibility in the timing of PET/CT for head and neck cancer patients due to undergo radiotherapy.

  14. Radiation shielding design of BNCT treatment room for D-T neutron source.

    PubMed

    Pouryavi, Mehdi; Farhad Masoudi, S; Rahmani, Faezeh

    2015-05-01

    Recent studies have shown that D-T neutron generator can be used as a proper neutron source for Boron Neutron Capture Therapy (BNCT) of deep-seated brain tumors. In this paper, radiation shielding calculations have been conducted based on the computational method for designing a BNCT treatment room for a recent proposed D-T neutron source. By using the MCNP-4C code, the geometry of the treatment room has been designed and optimized in such a way that the equivalent dose rate out of the treatment room to be less than 0.5μSv/h for uncontrolled areas. The treatment room contains walls, monitoring window, maze and entrance door. According to the radiation protection viewpoint, dose rate results of out of the proposed room showed that using D-T neutron source for BNCT is safe.

  15. Place of radiotherapy in the treatment of synovial sarcoma

    SciTech Connect

    Carson, J.H.; Harwood, A.R.; Cummings, B.J.; Fornasier, V.; Langer, F.; Quirt, I.

    1981-01-01

    This paper reviews 36 patients with synovial sarcoma; 18 were referred within three months of surgery. None had undergone en bloc excision and all were treated with post-operative radiotherapy. Local control and survival were analyzed with respect to Tumor Node Metastasis Classification, histology, site of primary and surgical procedure. Eight patients with T1-2N0M0 tumors were alive and well (minimum two year follow-up) following excision and radiotherapy; 7 had a normally functional extremity. In contrast, only one of 8 patients with T3N0M0 tumors is alive and well. Seven of 8 patients with well or moderately differentiated histology were alive and well whereas no patient with poorly differentiated histologies survived. Six of 7 patients were alive and well if their tumor was distal to the elbow or knee whereas none of those who had a primary thigh synovial sarcoma survived. Eighteen patients were referred with recurrent disease and 2 were salvaged. A management policy is proposed for synovial sarcoma with the integrated use of surgery, radiation and chemotherapy; it emphasizes optimal cure rates and a functional extremity reserving amputation for salvage.

  16. 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

  17. 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.

  18. The European Society of Therapeutic Radiology and Oncology-European Institute of Radiotherapy (ESTRO-EIR) report on 3D CT-based in-room image guidance systems: a practical and technical review and guide.

    PubMed

    Korreman, Stine; Rasch, Coen; McNair, Helen; Verellen, Dirk; Oelfke, Uwe; Maingon, Philippe; Mijnheer, Ben; Khoo, Vincent

    2010-02-01

    The past decade has provided many technological advances in radiotherapy. The European Institute of Radiotherapy (EIR) was established by the European Society of Therapeutic Radiology and Oncology (ESTRO) to provide current consensus statement with evidence-based and pragmatic guidelines on topics of practical relevance for radiation oncology. This report focuses primarily on 3D CT-based in-room image guidance (3DCT-IGRT) systems. It will provide an overview and current standing of 3DCT-IGRT systems addressing the rationale, objectives, principles, applications, and process pathways, both clinical and technical for treatment delivery and quality assurance. These are reviewed for four categories of solutions; kV CT and kV CBCT (cone-beam CT) as well as MV CT and MV CBCT. It will also provide a framework and checklist to consider the capability and functionality of these systems as well as the resources needed for implementation. Two different but typical clinical cases (tonsillar and prostate cancer) using 3DCT-IGRT are illustrated with workflow processes via feedback questionnaires from several large clinical centres currently utilizing these systems. The feedback from these clinical centres demonstrates a wide variability based on local practices. This report whilst comprehensive is not exhaustive as this area of development remains a very active field for research and development. However, it should serve as a practical guide and framework for all professional groups within the field, focussed on clinicians, physicists and radiation therapy technologists interested in IGRT.

  19. The role of radiotherapy in the treatment of muscle invasive bladder cancer

    SciTech Connect

    Porter, A.T. )

    1990-01-01

    The treatment of muscle invasive bladder cancer still remains controversial. It is becoming more clear, however, that attempts to retain the functional capacity of the urinary bladder by the use of non-surgical methods may be of benefit in the long-term. Studies using radiotherapy in combination with chemotherapeutic agents or intravesicle sensitizers, or the use of radiotherapy alone, but optimized (i.e., brachytherapy and altered fractionation) may be able to achieve improved local control while retaining a functional bladder. Attempts to couple this with improved survival due to the sterilization of occult metastases is still subject to much debate.51 references.

  20. 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

  1. Current trends in the treatment of ocular melanoma by radiotherapy.

    PubMed

    Hungerford, John L

    2003-02-01

    The Collaborative Ocular Melanoma Study (COMS) has recently confirmed once and for all that it is safe to attempt to preserve an eye with a posterior uveal melanoma by demonstrating no survival advantage of enucleation over plaque radiotherapy. While COMS has been under way, we have set out in London to define the selection criteria for conservative therapy versus enucleation for the various categories of melanoma in terms of size, location within the eye, and presence or absence of retinal detachment. The evolution of this approach has culminated in an overall ocular survival rate of 94% in 597 patients following radiation therapy combined with a mean loss of visual acuity of only 2.4 Snellen lines in the eyes preserved.

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

    PubMed

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

    2016-06-01

    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

  3. Contribution of activation products to occupational exposure following treatment using high-energy photons in radiotherapy.

    PubMed

    Petrović, Nina; Krestić-Vesović, Jelena; Stojanović, Darko; Ciraj-Bjelac, Olivera; Lazarević, Dorde; Kovacević, Milojko

    2011-01-01

    When high-energy photon beams are used for irradiation in radiotherapy, neutrons that are the result of photonuclear reactions create activation products that affect the occupational dose of radiotherapy staff. For the assessment of activation products in situ gamma spectroscopy was performed parallel to dose-rate measurements following irradiation, by using a high-energy photon beam from a linear accelerator Elekta Precise (Elekta, Stockholm, Sweden) used in radiotherapy. The major identified activation products were the following radioisotopes: (28)Al, (24)Na, (56)Mn, (54)Mn, (187)W, (64)Cu and (62)Cu. Based on the typical workload and dose-rate measurement, the assessed additional annual occupational dose ranged from 1.7 to 0.25 mSv. As the measured dose rate arising from the activation products rapidly decreases as a function of time, the assessed additional dose is negligible after 10 min following irradiation. To keep the occupational dose as low as reasonably achievable, it is recommended to delay entrance to the therapy room at least 2-4 min, when high-energy photons are used. This would reduce the effective dose by 30%.

  4. Unilateral parotid electron beam radiotherapy as palliative treatment for sialorrhea in amyotrophic lateral sclerosis.

    PubMed

    Kasarskis, Edward J; Hodskins, Jacob; St Clair, William H

    2011-09-15

    When ALS patients experience oropharyngeal weakness, sialorrhea can become a considerable challenge. Drooling has a profound negative impact in patient's quality of life causing embarrassing social situations. Several therapeutic modalities, including anticholinergic drugs, botulinum toxin injection, and radiotherapy have emerged as treatments for drooling in ALS. This retrospective case series study examined the effect of palliative radiotherapy in controlling problematic oral secretions in 10 ALS patients refractory to medical management. External electron beam radiation was targeted to a single parotid gland unilaterally with a total dose of 1500 cGy in 3 fractions at a depth determined by CT scanning. One patient received additional radiotherapy to the contralateral parotid due to persistent secretions. All patients reported improvement with a reduction in the intensity and amount of drooling. In 5 of 10 patients, anticholinergics were discontinued and were reduced in another two. There were no major side effects of treatment. We conclude that unilateral parotid electron radiotherapy provides satisfactory relief from sialorrhea in ALS patients and should be considered as a therapeutic option for patients who are refractory to medical management.

  5. 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.

  6. The use of intensity modulated radiotherapy for the treatment of extensive and recurrent juvenile angiofibroma.

    PubMed

    Kuppersmith, R B; Teh, B S; Donovan, D T; Mai, W Y; Chiu, J K; Woo, S Y; Butler, E B

    2000-05-30

    These case series are presented to describe the application and advantages of intensity modulated radiotherapy (IMRT) for the treatment of extensive and/or recurrent juvenile angiofibroma. Two patients were diagnosed with recurrence at 11 and 13 months postoperatively, and one was surgically unresectable. The affected areas included the base of skull, cavernous sinus, pterygopalatine fossa, infratemporal fossa, posterior orbit and nasopharynx. Highly conformal IMRT was delivered with limited radiation doses to the optic nerves, optic chiasm, brainstem, brain, spinal cord, lens, retina, mandible, and parotid. The total dose delivered to the tumor varied from 3400 to 4500 cGy. The tumor shrunk radiographically in all three cases and there was no endoscopic evidence of disease in two cases at 15 months and 40 months. There was no acute toxicity. Late toxicity was limited to one episode of epistaxis and persistent rhinitis in one patient. In conclusion, IMRT provides several advantages over conventional radiotherapy in the treatment of recurrent juvenile angiofibroma.

  7. 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.

  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. 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

  10. 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.

  11. 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.

  12. Monte Carlo simulation of the photoneutron field in linac radiotherapy treatments with different collimation systems

    NASA Astrophysics Data System (ADS)

    Zanini, A.; Durisi, E.; Fasolo, F.; Ongaro, C.; Visca, L.; Nastasi, U.; Burn, K. W.; Scielzo, G.; Adler, J. O.; Annand, J. R. M.; Rosner, G.

    2004-02-01

    Bremsstrahlung photon beams produced by linac accelerators are currently the most commonly used method of radiotherapy for tumour treatments. When the photon energy exceeds 10 MeV the patient receives an undesired dose due to photoneutron production in the accelerator head. In the last few decades, new sophisticated techniques such as multileaf collimators have been used for a better definition of the target volume. In this case it is crucial to evaluate the photoneutron dose produced after giant dipole resonance (GDR) excitation of the high Z materials (mainly tungsten and lead) constituting the collimator leaves in view of the optimization of the radiotherapy treatment. A Monte Carlo approach has been used to calculate the photoneutron dose arising from the GDR reaction during radiotherapy with energetic photon beams. The simulation has been performed using the code MCNP4B-GN which is based on MCNP4B, but includes a new routine GAMMAN to model photoneutron production. Results for the facility at IRCC (Istituto per la Ricerca e la Cura del Cancro) Candiolo (Turin), which is based on 18 MV x-rays from a Varian Clinac 2300 C/D, are presented for a variety of different collimator configurations.

  13. 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

  14. Compliance with antihypertensive treatment in consultation rooms for hypertensive patients.

    PubMed

    Balazovjech, I; Hnilica, P

    1993-12-01

    Compliance with antihypertensive therapy was examined by a questionnaire in 124 essential hypertension patients in an outpatient hypertension clinic. It was found that antihypertensive drugs were used regularly by only 62% of patients, with forgetting and feeling of well-being without therapy the principal reasons given for irregular drug taking. Treatment of hypertension is reported to have a deleterious effect on physical and mental activity, routine activities, sexual activity, memory, athletics and family life in only 2% of patients. Patients who were aware that increased BP reduces life span used the prescribed drugs more regularly and came regularly for checkups compared with patients lacking the relevant information. Patients over 60 years of age and smokers exhibited the worst compliance. No significant differences were found for sex or duration of treatment. With regard to nonpharmacological measures, most patients were willing to begin a programme of regular physical exercise, reduce weight, learn relaxation techniques and reduce alcohol intake: smokers, however were unable to stop the habit.

  15. 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

  16. AutoLock: a semiautomated system for radiotherapy treatment plan quality control.

    PubMed

    Dewhurst, Joseph M; Lowe, Matthew; Hardy, Mark J; Boylan, Christopher J; Whitehurst, Philip; Rowbottom, Carl G

    2015-01-01

    A semiautomated system for radiotherapy treatment plan quality control (QC), named AutoLock, is presented. AutoLock is designed to augment treatment plan QC by automatically checking aspects of treatment plans that are well suited to computational evaluation, whilst summarizing more subjective aspects in the form of a checklist. The treatment plan must pass all automated checks and all checklist items must be acknowledged by the planner as correct before the plan is finalized. Thus AutoLock uniquely integrates automated treatment plan QC, an electronic checklist, and plan finalization. In addition to reducing the potential for the propagation of errors, the integration of AutoLock into the plan finalization workflow has improved efficiency at our center. Detailed audit data are presented, demonstrating that the treatment plan QC rejection rate fell by around a third following the clinical introduction of AutoLock.

  17. 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.

  18. 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

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

    NASA Astrophysics Data System (ADS)

    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

  20. 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

  1. 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.

  2. 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).

  3. An interactive treatment planning system for ophthalmic plaque radiotherapy

    SciTech Connect

    Astrahan, M.A.; Luxton, G.; Jozsef, G.; Kampp, T.D.; Liggett, P.E.; Sapozink, M.D.; Petrovich, Z. )

    1990-03-01

    Brachytherapy using removable episcleral plaques containing sealed radioisotope sources is being studied as an alternative to enucleation in the treatment of choroidal melanoma and other tumors of the eye. Encouraging early results have been reported, but late complications which lead to loss of vision continue to be a problem. A randomized national study, the Collaborative Ocular Melanoma Study (COMS) is currently in progress to evaluate the procedure. The COMS specified isotope is 125I. Precise dosimetric calculations near the plaque may correlate strongly with complications and could also be used to optimize isotope loading patterns in the plaques. A microcomputer based treatment planning system has been developed for ophthalmic plaque brachytherapy. The program incorporates an interactive, 3-dimensional, solid-surface, color-graphic interface. The program currently supports 125I and 192Ir seeds which are treated as anisotropic line sources. Collimation effects related to plaque structure are accounted for, permitting detailed study of shielding effectiveness near the lip of a plaque. A dose distribution matrix may be calculated in any subregion of a transverse, sagittal, or coronal planar cross section of the eye, in any plane transecting the plaque and crossing the eye diametrically, or on a spherical surface within or surrounding the eye. Spherical surfaces may be displayed as 3-dimensional perspective projections or as funduscopic diagrams. Isodose contours are interpolated from the dose matrix. A pointer is also available to explicitly calculate and display dose at any location on the dosimetry surface. An interactive editing capability allows new plaque designs to be rapidly added to the system.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. DRR and portal image registration for automatic patient positioning in radiotherapy treatment.

    PubMed

    Bastida-Jumilla, Ma Consuelo; Larrey-Ruiz, Jorge; Verdú-Monedero, Rafael; Morales-Sánchez, Juan; Sancho-Gómez, José-Luis

    2011-12-01

    Image processing turns out to be essential in the planning and verification of radiotherapy treatments. Before applying a radiotherapy treatment, a dosimetry planning must be performed. Usually, the planning is done by means of an X-ray volumetric analysis using computerized tomography, where the area to be radiated is marked out. During the treatment phase, it is necessary to place the patient under the particle accelerator exactly as considered in the dosimetry stage. Coarse alignment is achieved using fiduciary markers placed over the patient's skin as external references. Later, fine alignment is provided by comparing a digitally reconstructed radiography (DRR) from the planning stage and a portal image captured by the accelerator in the treatment stage. The preprocessing of DRR and portal images, as well as the minimization of the non-shared information between both kinds of images, is mandatory for the correct operation of the image registration algorithm. With this purpose, mathematical morphology and image processing techniques have been used. The present work describes a fully automatic method to calculate more accurately the necessary displacement of the couch to place the patient exactly at the planned position. The proposed method to achieve the correct positioning of the patient is based on advanced image registration techniques. Preliminary results show a perfect match with the displacement estimated by the physician.

  9. DRR and portal image registration for automatic patient positioning in radiotherapy treatment.

    PubMed

    Bastida-Jumilla, Ma Consuelo; Larrey-Ruiz, Jorge; Verdú-Monedero, Rafael; Morales-Sánchez, Juan; Sancho-Gómez, José-Luis

    2011-12-01

    Image processing turns out to be essential in the planning and verification of radiotherapy treatments. Before applying a radiotherapy treatment, a dosimetry planning must be performed. Usually, the planning is done by means of an X-ray volumetric analysis using computerized tomography, where the area to be radiated is marked out. During the treatment phase, it is necessary to place the patient under the particle accelerator exactly as considered in the dosimetry stage. Coarse alignment is achieved using fiduciary markers placed over the patient's skin as external references. Later, fine alignment is provided by comparing a digitally reconstructed radiography (DRR) from the planning stage and a portal image captured by the accelerator in the treatment stage. The preprocessing of DRR and portal images, as well as the minimization of the non-shared information between both kinds of images, is mandatory for the correct operation of the image registration algorithm. With this purpose, mathematical morphology and image processing techniques have been used. The present work describes a fully automatic method to calculate more accurately the necessary displacement of the couch to place the patient exactly at the planned position. The proposed method to achieve the correct positioning of the patient is based on advanced image registration techniques. Preliminary results show a perfect match with the displacement estimated by the physician. PMID:21455811

  10. Radiation Dosimetry in the BNCT Patient Treatment Room at the Brookhaven Medical Research Reactor

    SciTech Connect

    Holden,N.; Reciniello, R.; Hu, J.

    2006-01-01

    The BMRR was a 3 MW light water reactor that had an epithermal neutron beam that was used to perform clinical trials on patients with malignant brain tumors. A series of measurements and calculations had been performed in the treatment room both prior to the trials and during the trials. The details of the measurements and the Monte Carlo calculations are presented and compared.

  11. LPT. Shield test facility (TAN646) interior. Water treatment room contains ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LPT. Shield test facility (TAN-646) interior. Water treatment room contains water softeners, deionizers, and display panel. Note metal ceiling and walls. Photographer: Jack L. Anderson. Date: February 20, 1959. INEEL negative no. 59-856 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  12. A CT calibration method based on the polybinary tissue model for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Kanematsu, Nobuyuki; Matsufuji, Naruhiro; Kohno, Ryosuke; Minohara, Shinichi; Kanai, Tatsuaki

    2003-04-01

    A method to establish the relationship between CT number and effective density for therapeutic radiations is proposed. We approximated body tissues to mixtures of muscle, air, fat and bone. Consequently, the relationship can be calibrated only with a CT scan of their substitutes, for which we chose water, air, ethanol and potassium phosphate solution, respectively. With simple and specific corrections for non-equivalencies of the substitutes, a calibration accuracy of 1% will be achieved. We tested the calibration method with some biological materials to verify that the proposed method would offer the accuracy, simplicity and specificity required for a standard in radiotherapy treatment planning, in particular with heavy charged particles.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. Radiation-induced temporo-mandibular joint disorder in post-radiotherapy nasopharyngeal carcinoma patients: assessment and treatment.

    PubMed

    Wu, Vincent W C; Lam, Ying-Na

    2016-06-01

    Nasopharyngeal carcinoma (NPC) is endemic in southern China, and its incidence in Hong Kong is relatively high. Radiotherapy is the mainstay treatment for NPC due to its relatively high radiosensitivity and deep-seated anatomical position, which is not readily accessible by surgery. Although the technique of radiotherapy in NPC has been advancing and offers promising treatment outcome, complications around the irradiation areas are inevitable and the quality of life of the post-radiotherapy patients is often compromised. Trismus, which is defined as the restricted mouth opening or jaw movement due to the disorder of temporo-mandibular joint (TMJ), is one of the possible late complications for radiotherapy of NPC and is found in 5-17% of the post-radiotherapy (post-RT) patients. Trismus at early stage may only affect the speech, but in severe cases nutritional intake and oral hygiene condition may deteriorate seriously. This article reviewed the possible causes of radiation-induced TMJ damage, the various assessments including imaging modalities and possible treatments. The conclusion is that the availability of simple, yet effective examinations for trismus is essential for delaying the progression and restoring TMJ functions. Although there is no absolutely effective treatment for trismus, many supportive, restorative and palliative management are possible under different clinical situations.

  19. 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

  20. 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.

  1. Emergency room assessment and adrenaline treatment of patients with acute asthma of different severity.

    PubMed

    Limthongkul, S

    1989-06-01

    The adequacy of emergency room assessment and treatment of patients with acute severe asthmatic attacks was evaluated by analyzing the course of 451 visits of 348 patients to Chulalongkorn hospital's Emergency Room. Eighty-five per cent of the patients had an initial index score of greater than or equal to 4 and an average peak expiratory flow rate of 92.16 +/- 46.3 L/min. The discharge index score was 85 per cent with a score of less than or equal to 3 and an average peak expiratory flow rate of 192 +/- 40.3 L/min. Our study indicated that the predictive index proposed by Fischl et al correlated with the severity of airway obstruction; however, the initial index did not help with emergency room decision-making in predicting which patients might be hospitalized, have a relapse or be discharged. In fact, in our emergency room department, the index score to determine airway obstruction and the pattern of response to treatment were better predictors of the outcome, which was classified into three categories: non-responsive or minimally responsive, responsive, and partially responsive. By using conventional clinical criteria (i.e. recumbent position with elimination of laboured breathing, disappearance of dyspnea and reduction of wheezing), there was a 93 per cent accurate determination in the episodes of patients who responded sufficiently to the emergency room treatment to allow their discharge. The remaining 7 per cent of those seeking emergency treatment were hospitalized, which is a lower incidence than that of others series.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Radiotherapy and Hyperthermia for Treatment of Primary Locally Advanced Cervix Cancer: Results in 378 Patients

    SciTech Connect

    Franckena, Martine Lutgens, Ludy C.; Koper, Peter C.; Kleynen, Catharina E.; Steen-Banasik, Elsbieta M. van der; Jobsen, Jan J.; Leer, Jan Willem; Creutzberg, Carien L.; Dielwart, Michel F.; Norden, Yvette van; Canters, Richard A.M.; Rhoon, Gerard C. van; Zee, Jacoba van der

    2009-01-01

    Purpose: To report response rate, pelvic tumor control, survival, and late toxicity after treatment with combined radiotherapy and hyperthermia (RHT) for patients with locally advanced cervical carcinoma (LACC) and compare the results with other published series. Methods and Materials: From 1996 to 2005, a total of 378 patients with LACC (International Federation of Gynecology and Obstetrics Stage IB2-IVA) were treated with RHT. External beam radiotherapy (RT) was applied to 46-50.4 Gy and combined with brachytherapy. The hyperthermia (HT) was prescribed once weekly. Primary end points were complete response (CR) and local control. Secondary end points were overall survival, disease-specific survival, and late toxicity. Patient, tumor, and treatment characteristics predictive for the end points were identified in univariate and multivariate analyses. Results: Overall, a CR was achieved in 77% of patients. At 5 years, local control, disease-specific survival, and incidence of late toxicity Common Terminology Criteria for Adverse Events Grade 3 or higher were 53%, 47%, and 12%, respectively. In multivariate analysis, number of HT treatments emerged as a predictor of outcome in addition to commonly identified prognostic factors. Conclusions: The CR, local control, and survival rates are similar to previously observed results of RHT in the randomized Dutch Deep Hyperthermia Trial. Reported treatment results for currently applied combined treatment modalities (i.e., RT with chemotherapy and/or HT) do not permit definite conclusions about which combination is superior. The present results confirm previously shown beneficial effects from adding HT to RT and justify the application of RHT as first-line treatment in patients with LACC as an alternative to chemoradiation.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. [Uterine cervix cancer. Clinical stage III. Combined radiotherapy and chemotherapy treatment].

    PubMed

    Ayala Hernández, J R; de la Huerta Sánchez, R; Morales Canfield, F; Fernández Orozco, A

    1991-07-01

    55 patients with stage III carcinoma of the uterine cervix were entered into a prospective randomized study to evaluate the possible radiation-potentiating properties of bleomycin. Group A received classical radiation treatment with telecobalt-therapy 50 Gy/25 fractions plus 32 Gy/4 fractions (Cathetron). The other two groups received 15 mg of bleomycin by continue infusion two time of week during 5 week, groups B before, and group C after, irradiation. The morbidity was minimal. The initial response was complete in 49 cases and partial in 6 cases. At 2 years there were 26 recurrences, 22 (88.8%), locoregional recurrences and 4 distant metastasis, 3 in the group of bleomycin treatment. The probability of actuarial survival was 62.1%, 30.1% and 35.6% respectively to groups A, B and C. Addition of bleomycin to radiotherapy failed to increase the recurrence-free survival.

  9. Deriving margins in prostate cancer radiotherapy treatment: comparison of neural network and fuzzy logic models.

    PubMed

    Mzenda, Bongile; Gegov, Alexander; Brown, David J; Petrov, Nedyalko

    2012-01-01

    This study investigates the feasibility of using Artificial Neural Network (ANN) and fuzzy logic based techniques to select treatment margins for dynamically moving targets in the radiotherapy treatment of prostate cancer. The use of data from 15 patients relating error effects to the Tumour Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) radiobiological indices was contrasted against the use of data based on the prostate volume receiving 99% of the prescribed dose (V99%) and the rectum volume receiving more than 60Gy (V60). For the same input data, the results of the ANN were compared to results obtained using a fuzzy system, a fuzzy network and current clinically used statistical techniques. Compared to fuzzy and statistical methods, the ANN derived margins were found to be up to 2 mm larger at small and high input errors and up to 3.5 mm larger at medium input error magnitudes.

  10. 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

  11. 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.

  12. 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.

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

    PubMed

    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.

  14. SU-E-J-39: Comparison of PTV Margins Determined by In-Room Stereoscopic Image Guidance and by On-Board Cone Beam Computed Tomography Technique for Brain Radiotherapy Patients

    SciTech Connect

    Ganesh, T; Paul, S; Munshi, A; Sarkar, B; Krishnankutty, S; Sathya, J; George, S; Jassal, K; Roy, S; Mohanti, B

    2014-06-01

    Purpose: Stereoscopic in room kV image guidance is a faster tool in daily monitoring of patient positioning. Our centre, for the first time in the world, has integrated such a solution from BrainLAB (ExacTrac) with Elekta's volumetric cone beam computed tomography (XVI). Using van Herk's formula, we compared the planning target volume (PTV) margins calculated by both these systems for patients treated with brain radiotherapy. Methods: For a total of 24 patients who received partial or whole brain radiotherapy, verification images were acquired for 524 treatment sessions by XVI and for 334 sessions by ExacTrac out of the total 547 sessions. Systematic and random errors were calculated in cranio-caudal, lateral and antero-posterior directions for both techniques. PTV margins were then determined using van Herk formula. Results: In the cranio-caudal direction, systematic error, random error and the calculated PTV margin were found to be 0.13 cm, 0.12 cm and 0.41 cm with XVI and 0.14 cm, 0.13 cm and 0.44 cm with ExacTrac. The corresponding values in lateral direction were 0.13 cm 0.1 cm and 0.4 cm with XVI and 0.13 cm, 0.12 cm and 0.42 cm with ExacTrac imaging. The same parameters for antero-posterior were for 0.1 cm, 0.11 cm and 0.34 cm with XVI and 0.13 cm, 0.16 cm and 0.43 cm with ExacTrac imaging. The margins estimated with the two imaging modalities were comparable within ± 1 mm limit. Conclusion: Verification of setup errors in the major axes by two independent imaging systems showed the results are comparable and within ± 1 mm. This implies that planar imaging based ExacTrac can yield equal accuracy in setup error determination as the time consuming volumetric imaging which is considered as the gold standard. Accordingly PTV margins estimated by this faster imaging technique can be confidently used in clinical setup.

  15. 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.

  16. 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.

  17. 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. )

  18. Assessing small-volume spinal cord dose for repeat spinal stereotactic body radiotherapy treatments

    NASA Astrophysics Data System (ADS)

    Ma, Lijun; Kirby, Neil; Korol, Renee; Larson, David A.; Sahgal, Arjun

    2012-12-01

    Spinal cord biologically effective dose (BED) limits are critical to safe spine stereotactic body radiotherapy (SBRT) delivery. In particular, when repeating SBRT to the same site, the problem of adding non-uniform BED distributions within small volumes of spinal cord has yet to be solved. We report a probability-based generalized BED (gBED) model to guide repeat spine SBRT treatment planning. The gBED was formulated by considering the sequential damaging probabilities of repeat spine SBRT treatments. Parameters from the standard linear-quadratic model, such as α/β = 2 Gy for the spinal cord, were applied. We tested the model based on SBRT specific spinal cord tolerance using a simulated and ten clinical repeat SBRT cases. The gBED provides a consistent solution for superimposing non-uniform dose distributions from different fractionation schemes, analogous to the BED for uniform dose distributions. Based on ten clinical cases, the gBED was observed to eliminate discrepancies in the cumulative BED of approximately 5% to 20% within small volumes (e.g. 0.1-2.0 cc) of spinal cord, as compared to a conventional calculation method. When assessing spinal cord tolerance for repeat spinal SBRT treatments, caution should be exercised when applying conventional BED calculations for small volumes of spinal cord irradiated, and the gBED potentially provides more conservative and consistently derived dose surrogates to guide safe treatment planning and treatment outcome modeling.

  19. 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

  20. The role of radiotherapy in the treatment of bile duct carcinoma.

    PubMed

    Veeze-Kuijpers, B; Meerwaldt, J H; Lameris, J S; van Blankenstein, M; van Putten, W L; Terpstra, O T

    1990-01-01

    Forty-two patients with irresectable bile duct carcinoma (n = 31) or with microscopic evidence of tumor rest after aggressive surgery for bile duct carcinoma (n = 11) were given radiotherapy consisting intentionally of external-beam therapy and intraluminal 192Iridium (192Ir) wire application(s) following bile drainage procedures. The treatment was well tolerated; complications were mainly infectious and related to the success of the drainage. A median survival of 10 months was achieved for the group as a whole. Patients treated following microscopically incomplete resection survived longer than patients with an irresectable tumor (15 vs 8 months median survival, p = 0.06). Gross lymph node involvement also proved to be a prognostic factor.

  1. 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.

  2. The role of radiotherapy in the treatment of bile duct carcinoma.

    PubMed

    Veeze-Kuijpers, B; Meerwaldt, J H; Lameris, J S; van Blankenstein, M; van Putten, W L; Terpstra, O T

    1990-01-01

    Forty-two patients with irresectable bile duct carcinoma (n = 31) or with microscopic evidence of tumor rest after aggressive surgery for bile duct carcinoma (n = 11) were given radiotherapy consisting intentionally of external-beam therapy and intraluminal 192Iridium (192Ir) wire application(s) following bile drainage procedures. The treatment was well tolerated; complications were mainly infectious and related to the success of the drainage. A median survival of 10 months was achieved for the group as a whole. Patients treated following microscopically incomplete resection survived longer than patients with an irresectable tumor (15 vs 8 months median survival, p = 0.06). Gross lymph node involvement also proved to be a prognostic factor. PMID:2153649

  3. 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.

  4. The role of radiotherapy in the treatment of bile duct carcinoma

    SciTech Connect

    Veeze-Kuijpers, B.; Meerwaldt, J.H.; Lameris, J.S.; van Blankenstein, M.; van Putten, W.L.; Terpstra, O.T. )

    1990-01-01

    Forty-two patients with irresectable bile duct carcinoma (n = 31) or with microscopic evidence of tumor rest after aggressive surgery for bile duct carcinoma (n = 11) were given radiotherapy consisting intentionally of external-beam therapy and intraluminal 192Iridium ({sup 192}Ir) wire application(s) following bile drainage procedures. The treatment was well tolerated; complications were mainly infectious and related to the success of the drainage. A median survival of 10 months was achieved for the group as a whole. Patients treated following microscopically incomplete resection survived longer than patients with an irresectable tumor (15 vs 8 months median survival, p = 0.06). Gross lymph node involvement also proved to be a prognostic factor.

  5. 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.

  6. 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

  7. 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.

  8. Evaluation of a metal artifact reduction algorithm in CT studies used for proton radiotherapy treatment planning.

    PubMed

    Andersson, Karin M; Ahnesjö, Anders; Vallhagen Dahlgren, Christina

    2014-09-08

    Metal objects in the body such as hip prostheses cause artifacts in CT images. When CT images degraded by artifacts are used for treatment planning of radiotherapy, the artifacts can yield inaccurate dose calculations and, for particle beams, erroneous penetration depths. A metal artifact reduction software (O-MAR) installed on a Philips Brilliance Big Bore CT has been tested for applications in treatment planning of proton radiotherapy. Hip prostheses mounted in a water phantom were used as test objects. Images without metal objects were acquired and used as reference data for the analysis of artifact-affected regions outside of the metal objects in both the O-MAR corrected and the uncorrected images. Water equivalent thicknesses (WET) based on proton stopping power data were calculated to quantify differences in the calculated proton beam penetration for the different image sets. The WET to a selected point of interest between the hip prostheses was calculated for several beam directions of clinical relevance. The results show that the calculated differences in WET relative to the reference case were decreased when the O-MAR algorithm was applied. WET differences up to 2.0 cm were seen in the uncorrected case while, for the O-MAR corrected case, the maximum difference was decreased to 0.4 cm. The O-MAR algorithm can significantly improve the accuracy in proton range calculations. However, there are some residual effects, and the use of proton beam directions along artifact streaks should only be used with caution and appropriate margins.

  9. 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.

  10. Radiobiological comparison of two radiotherapy treatment techniques for high-risk prostate cancer

    PubMed Central

    Hernández, Trinitat García; González, Aurora Vicedo; Peidro, Jorge Pastor; Ferrando, Juan V. Roselló; González, Luis Brualla; Cabañero, Domingo Granero; Torrecilla, José López

    2013-01-01

    Background To make a radiobiological comparison, for high risk prostate cancer (T3a, PSA > 20 ng/ml or Gleason > 7) of two radiotherapy treatment techniques. One technique consists of a treatment in three phases of the pelvic nodes, vesicles and prostate using a conventional fractionation scheme of 2 Gy/fraction (SIMRT). The other technique consists of a treatment in two phases that gives simultaneously different dose levels in each phase, 2 Gy/fraction, 2.25 Gy/fraction and 2.5 Gy/fraction to the pelvic nodes, vesicles and prostate, respectively (SIBIMRT). Materials and methods The equivalent dose at fractionation of 2 Gy (EQD2), calculated using the linear quadratic model with α/βprostate = 1.5 Gy, was the same for both treatment strategies. For comparison the parameters employed were D95, mean dose and Tumour Control Probabilities for prostate PTV and D15, D25, D35, D50, mean dose and Normal Tissue Complication Probabilities for the rectum and bladder, with physical doses converted to EQD2. Parameters were obtained for α/βprostate = 1.5, 3 and 10 Gy and for α/βoar = 1, 2, 3, 4, 6 and 8. Results For prostate PTV, both treatment strategies are equivalent for α/βprostate = 1.5 Gy but for higher α/βprostate, EQD2 and TCP, decrease for the SIBIMRT technique. For the rectum and bladder when α/βoar ≤ 2 Gy, EQD2 and NTCP are lower for the SIMRT technique or equal in both techniques. For α/βoar ≥ 2–3 Gy, EQD2 and NTCP increase for the SIMRT treatment. Conclusions A comparison between two radiotherapy techniques is presented. The SIBIMRT technique reduces EQD2 and NTCP for α/βoar from 2 to 8 Gy. PMID:24416563

  11. Use of Monte Carlo computation in benchmarking radiotherapy treatment planning system algorithms

    NASA Astrophysics Data System (ADS)

    Lewis, R. D.; Ryde, S. J. S.; Seaby, A. W.; Hancock, D. A.; Evans, C. J.

    2000-07-01

    Radiotherapy treatments are becoming more complex, often requiring the dose to be calculated in three dimensions and sometimes involving the application of non-coplanar beams. The ability of treatment planning systems to accurately calculate dose under a range of these and other irradiation conditions requires evaluation. Practical assessment of such arrangements can be problematical, especially when a heterogeneous medium is used. This work describes the use of Monte Carlo computation as a benchmarking tool to assess the dose distribution of external photon beam plans obtained in a simple heterogeneous phantom by several commercially available 3D and 2D treatment planning system algorithms. For comparison, practical measurements were undertaken using film dosimetry. The dose distributions were calculated for a variety of irradiation conditions designed to show the effects of surface obliquity, inhomogeneities and missing tissue above tangential beams. The results show maximum dose differences of 47% between some planning algorithms and film at a point 1 mm below a tangentially irradiated surface. Overall, the dose distribution obtained from film was most faithfully reproduced by the Monte Carlo N-Particle results illustrating the potential of Monte Carlo computation in evaluating treatment planning system algorithms.

  12. 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.

  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. [Duokangjiasu combined with radiotherapy in the treatment of 32 nasopharyngeal carcinoma (NPC) patients].

    PubMed

    Li, Q Q

    1988-07-01

    The results of 32 NPC patients treated by duokangjiasu combined with radiotherapy or radiotherapy alone are reported. Subjects were divided into two groups, combined and control groups with 16 patients each. The results showed that the patients treated with combination of duokangjiasu and radiotherapy had less decrease in blood IgM level than the controls treated with radiotherapy alone. Therefore, it indicates that duokangjiasu may stabilized immune function in vivo at a normal level and remarkably accelerate the resolution or eradication of the primary focus in the nasopharynx. PMID:3248490

  15. 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.

  16. 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

  17. 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.

  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.

  19. 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.

  20. Planning combined treatments of external beam radiation therapy and molecular radiotherapy.

    PubMed

    Cremonesi, Marta; Ferrari, Mahila; Botta, Francesca; Guerriero, Francesco; Garibaldi, Cristina; Bodei, Lisa; De Cicco, Concetta; Grana, Chiara Maria; Pedroli, Guido; Orecchia, Roberto

    2014-08-01

    Molecular radiotherapy (MRT) with radiolabeled molecules has being constantly evolving, leading to notable results in cancer treatment. In some cases, the absorbed doses delivered to tumors by MRT are sufficient to obtain complete responses; in other cases, instead, to be effective, MRT needs to be combined with other therapeutic approaches. Recently, several studies proposed the combination of MRT with external beam radiation therapy (EBRT). Some describe the theoretical basis within radiobiological models, others report the results of clinical phase I-II studies aimed to assess the feasibility and tolerability. The latter includes the treatment of various tumors, such as meningiomas, paragangliomas, non-Hodgkin's lymphomas, bone, brain, hepatic, and breast lesions. The underlying principle of combined MRT and EBRT is the possibility of exploiting the full potential of each modality, given the different organs at risk. Target tissues can indeed receive a higher irradiation, while respecting the threshold limits of more than one critical tissue. Nevertheless, clinical trials are empirical and optimization is still a theoretical issue. This article describes the state of the art of combined MRT and EBRT regarding the rationale and the results of clinical studies, with special focus on the possibility of treatment improvement.

  1. Treatment outcomes and late complications of 849 patients with nasopharyngeal carcinoma treated with radiotherapy alone

    SciTech Connect

    Yeh, S.-A. . E-mail: yehsa@hotmail.com; Tang Yeh; Lui, C.-C.; Huang, Y.-J.; Huang, E.-Y.

    2005-07-01

    Purpose: The objective of this study was to describe the treatment outcomes and treatment-related complications of nasopharyngeal carcinoma (NPC) patients treated with radiotherapy alone. Methods and Materials: Retrospective analysis was performed on 849 consecutive NPC patients treated between 1983 and 1998 in our institution. Potentially significant patient-related and treatment-related variables were analyzed. Radiation-related complications were recorded. Results: The 5-year overall and disease-free survival rates of these patients were 59% and 52%, respectively. Advanced parapharyngeal space (PPS) invasion showed stronger prognostic value than PPS invasion. Multiple neck lymph node (LN) involvement was demonstrated to be one of the most powerful independent prognostic factors among all LN-related parameters. External beam radiation dose more than 72 Gy was associated with significantly higher incidence of hearing impairment, trismus, and temporal lobe necrosis. Conclusions: We recommend that the extent of PPS should be clarified and stratified. Multiple neck LN involvement could be integrated into the N-classification in further revisions of the American Joint Committee on Cancer stage. Boost irradiation is not suggested for node-negative necks. For node-positive necks, boost irradiation is indicated and a longer interval between initial and boost irradiation would reduce the incidence of neck fibrosis without compromising the neck control rate.

  2. 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.

  3. [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

  4. A new role of PET/CT for target delineation for radiotherapy treatment planning for head and neck carcinomas.

    PubMed

    Zygogianni, Anna; Kyrgias, George; Kouvaris, John; Pistevou-Gompaki, Kyriaki; Kouloulias, Vassilis

    2012-01-01

    Fluorine-18-fluorodeoxyglucose- positron emission tomography ((18)F-FDG PET) in head and neck cancer patients is useful for staging, identification of macroscopic disease, detection of invaded lymph nodes and distant metastases, delineation of radiotherapy target volume and assessment of treatment response. This brief review addresses the potential role of PET in radiotherapy planning as compared to MRI and CT scan. Positron emission tomography is considered by radiation oncologists a useful test for the identification of the specific target volume for treatment. In addition, a number of hypoxia-related PET radiopharmaceuticals such as the fluorine-18-fluoromisonidazole ((18)F-FMISO) and the fluorine-18-fluoroazomycin arabinoside ((18)F-FAZA) are now available in order to identify hypoxic tumor subvolumes helping to implement new radiotherapy techniques. Magnetic resonance imaging (MRI) has the advantage to discriminate the soft tissue contrast from the tumor, against computerized tomography (CT), but PET/CT scans have the additional advantage to incorporate the metabolic imaging for improving the delineation of variable and hypoxic tumor tissue in the head and neck region. Regardless of the method used for determining the gross tumor volume, clinical examination remains irreplaceable. In conclusion, PET/CT offers complementary information for the delineation of the primary tumor and the corresponding lymph nodes compared to the use of MRI and CT and can support the use of modern radiotherapy techniques, having fewer toxicities.

  5. Ultrafast Room-Temperature Crystallization of TiO2 Nanotubes Exploiting Water-Vapor Treatment

    PubMed Central

    Lamberti, Andrea; Chiodoni, Angelica; Shahzad, Nadia; Bianco, Stefano; Quaglio, Marzia; Pirri, Candido F.

    2015-01-01

    In this manuscript a near-room temperature crystallization process of anodic nanotubes from amorphous TiO2 to anatase phase with a fast 30 minutes treatment is reported for the first time. This method involves the exposure of as-grown TiO2 nanotubes to water vapor flow in ambient atmosphere. The water vapor-crystallized samples are deeply investigated in order to gain a whole understanding of their structural, physical and chemical properties. The photocatalytic activity of the converted material is tested by dye degradation experiment and the obtained performance confirms the highly promising properties of this low-temperature processed material. PMID:25589038

  6. Escherichia coli inactivation by pressurized CO2 treatment methods at room temperature: Critical issues.

    PubMed

    Zhang, Yongji; Huang, Doudou; Zhou, Lingling

    2016-05-01

    This study aims to increase the inactivation efficiency of CO2 against Escherichia coli under mild conditions to facilitate the application of pressurized CO2 technology in water disinfection. Based on an aerating-cycling apparatus, three different treatment methods (continuous aeration, continuous reflux, and simultaneous aeration and reflux) were compared for the same temperature, pressure (0.3-0.7MPa), initial concentration, and exposure time (25min). The simultaneous aeration and reflux treatment (combined method) was shown to be the best method under optimum conditions, which were determined to be 0.7MPa, room temperature, and an exposure time of 10min. This treatment achieved 5.1-log reduction after 25min of treatment at the pressure of 0.3MPa and 5.73-log reduction after 10min at 0.7MPa. Log reductions of 4.4 and 5.0 occurred at the end of continuous aeration and continuous reflux treatments at 0.7MPa, respectively. Scanning electron microscopy (SEM) images suggested that cells were ruptured after the simultaneous aeration and reflux treatment and the continuous reflux treatment. The increase of the solubilization rate of CO2 due to intense hydraulic conditions led to a rapid inactivation effect. It was found that the reduction of intracellular pH caused by CO2 led to a more lethal bactericidal effect. PMID:27155435

  7. 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.

  8. 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

  9. Radiotherapy treatment of early stage prostate cancer with IMRT and protons: a treatment planning comparison

    PubMed Central

    Trofimov, Alexei; Nguyen, Paul L.; Coen, John J.; Doppke, Karen P.; Schneider, Robert J.; Adams, Judith A.; Bortfeld, Thomas R.; Zietman, Anthony L.; DeLaney, Thomas F.; Shipley, William U.

    2009-01-01

    Purpose To compare intensity-modulated photon radiotherapy (IMRT) with 3D-conformal proton therapy (3D-CPT) for early stage prostate cancer, and explore the potential utility of intensity-modulated proton therapy (IMPT). Methods Ten patients were planned with both 3D-CPT (2 parallel-opposed lateral fields) and IMRT (7 equally spaced coplanar fields). Prescribed dose was 79.2 Gy (or cobalt Gray-equivalent, CGE for protons) to the prostate gland. Dose-volume histograms, dose conformity, and equivalent uniform dose (EUD) were compared. Additionally, plans were optimized for 3D-CPT with non-standard beam configuration, and for IMPT assuming delivery with beam scanning. Results At least 98% of the PTV received the prescription dose. IMRT plans yielded better dose conformity to the target, while proton plans achieved higher dose homogeneity, and better sparing of rectum and bladder in the range below 30 Gy/CGE. Bladder volumes receiving over 70 Gy/CGE (V70) were reduced, on average, by 34% with IMRT vs. 3D-CPT, while rectal V70 were equivalent. EUD from 3D-CPT and IMRT plans were indistinguishable within uncertainties, for both bladder and rectum. With the use of small-angle lateral-oblique fields in 3D-CPT and IMPT, the rectal V70 was reduced by up to 35% compared to the standard lateral configuration, while the bladder V70 increased by less than 10%. Conclusions In the range over 60 Gy/CGE, IMRT achieved significantly better sparing of the bladder, while rectal sparing was similar with 3D-CPT and IMRT. Dose to healthy tissues in the range below 50% of the target prescription was substantially lower with proton therapy. PMID:17513063

  10. 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

  11. 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

  12. 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.

  13. Radiotherapy to the salivary glands as treatment of sialorrhea in patients with parkinsonism.

    PubMed

    Postma, Anna-Gerlind; Heesters, Mart; van Laar, Teus

    2007-12-01

    This study investigated retrospectively the long-term efficacy and safety of radiotherapy (RT) to the major salivary glands as treatment of sialorrhea in patients with parkinsonism. Twenty-eight patients received a bilateral dose of 12 Gy to the parotid and part of the submandibular glands between 2001 and 2006. Severity of sialorrhea and adverse events were assessed at 1 and 6 months post-RT and finally in the first quarter of 2007. Item 6 of the activities of daily living-section of the Unified Parkinson's Disease Rating Scale was used as primary endpoint. Quality of life (QoL) pre- and post-RT was investigated using a shortened Parkinson's Disease Questionnaire-8. Sialorrhea had improved significantly at 1 month post-RT and this effect was maintained for at least 1 year. Most frequent adverse events were loss of taste and a dry mouth; however, 75% of these adverse events were transient. QoL had improved significantly on the long term. The clinical global impression scores at the final follow-up showed that 80% of patients were satisfied. It was concluded that RT is an effective and safe treatment of sialorrhea on the long term in patients with parkinsonism.

  14. Control of a HexaPOD treatment couch for robot-assisted radiotherapy.

    PubMed

    Hermann, Christian; Ma, Lei; Wilbert, Jürgen; Baier, Kurt; Schilling, Klaus

    2012-10-01

    Moving tumors, for example in the vicinity of the lungs, pose a challenging problem in radiotherapy, as healthy tissue should not be irradiated. Apart from gating approaches, one standard method is to irradiate the complete volume within which a tumor moves plus a safety margin containing a considerable volume of healthy tissue. This work deals with a system for tumor motion compensation using the HexaPOD® robotic treatment couch (Medical Intelligence GmbH, Schwabmünchen, Germany). The HexaPOD, carrying the patient during treatment, is instructed to perform translational movements such that the tumor motion, from the beams-eye view of the linear accelerator, is eliminated. The dynamics of the HexaPOD are characterized by time delays, saturations, and other non-linearities that make the design of control a challenging task. The focus of this work lies on two control methods for the HexaPOD that can be used for reference tracking. The first method uses a model predictive controller based on a model gained through system identification methods, and the second method uses a position control scheme useful for reference tracking. We compared the tracking performance of both methods in various experiments with real hardware using ideal reference trajectories, prerecorded patient trajectories, and human volunteers whose breathing motion was compensated by the system.

  15. [Application of radiotherapy in perioperative comprehensive treatment for the elderly with rectal cancer].

    PubMed

    Cai, Xin; Zhang, Zhen

    2016-05-01

    Considered that most of the phase II or III clinical trials contain less elderly patients or only contain those who had good health status, these results might not be applied in those elderly patients with some complex status. The patients of 70 years old or more usually have complications or worse organ function, thus the standard treatment for them becomes a gray zone. In rectal cancer patients, the rate of elderly patients receiving standard chemoradiotherapy (CRT) is obviously lower than that of the younger ones. More and more retrospective studies found that the prognosis of the elderly (≥70) who received neo-adjuvant or adjuvant CRT was better than that of those who received surgery or radiotherapy only, and the outcome of the above-mentioned elderly was similar to those of other phase III trial or younger patients with good tolerance. In addition, some studies revealed patients with good status, less or slight complications had a better prognosis. The advance of radiation therapy, such as Image-guided Radiation Therapy (IGRT), Intensity-modulated Radiation Therapy (IMRT), Stereotactic Body Radiation Therapy (SBRT), brachytherapy and particle therapy, will benefit the elderly cancer patients. We think that treatments recommended to the elderly will become more personalized.

  16. 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.

  17. A comparison between cobalt and linear accelerator-based treatment plans for conformal and intensity-modulated radiotherapy.

    PubMed

    Adams, E J; Warrington, A P

    2008-04-01

    The simplicity of cobalt units gives them the advantage of reduced maintenance, running costs and downtime when compared with linear accelerators. However, treatments carried out on such units are typically limited to simple techniques. This study has explored the use of cobalt beams for conformal and intensity-modulated radiotherapy (IMRT). Six patients, covering a range of treatment sites, were planned using both X-ray photons (6/10 MV) and cobalt-60 gamma rays (1.17 and 1.33 MeV). A range of conformal and IMRT techniques were considered, as appropriate. Conformal plans created using cobalt beams for small breast, meningioma and parotid cases were found to compare well with those created using X-ray photons. By using additional fields, acceptable conformal plans were also created for oesophagus and prostate cases. IMRT plans were found to be of comparable quality for meningioma, parotid and thyroid cases on the basis of dose-volume histogram analysis. We conclude that it is possible to plan high-quality radical radiotherapy treatments for cobalt units. A well-designed beam blocking/compensation system would be required to enable a practical and efficient alternative to multileaf collimator (MLC)-based linac treatments to be offered. If cobalt units were to have such features incorporated into them, they could offer considerable benefits to the radiotherapy community.

  18. 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

  19. Comparison of linac-based fractionated stereotactic radiotherapy and tomotherapy treatment plans for intra-cranial tumors

    NASA Astrophysics Data System (ADS)

    Jang, Bo Shim; Suk, Lee; Sam, Ju Cho; Sang, Hoon Lee; Juree, Kim; Kwang, Hwan Cho; Chul, Kee Min; Hyun Do, Huh; Rena, Lee; Dae, Sik Yang; Young, Je Park; Won, Seob Yoon; Chul, Yong Kim; Soo, Il Kwon

    2010-11-01

    This study compares and analyzes stereotactic radiotherapy using tomotherapy and linac-based fractionated stereotactic radiotherapy in the treatment of intra-cranial tumors, according to some cases. In this study, linac-based fractionated stereotactic radiotherapy and tomotherapy treatment were administered to five patients diagnosed with intra-cranial cancer in which the dose of 18-20 Gy was applied on 3-5 separate occasions. The tumor dosing was decided by evaluating the inhomogeneous index (II) and conformity index (CI). Also, the radiation-sensitive tissue was evaluated using low dose factors V1, V2, V3, V4, V5, and V10, as well as the non-irradiation ratio volume (NIV). The values of the II for each prescription dose in the linac-based non-coplanar radiotherapy plan and tomotherapy treatment plan were (0.125±0.113) and (0.090±0.180), respectively, and the values of the CI were (0.899±0.149) and (0.917±0.114), respectively. The low dose areas, V1, V2, V3, V4, V5, and V10, in radiation-sensitive tissues in the linac-based non-coplanar radiotherapy plan fell into the ranges 0.3%-95.6%, 0.1%-87.6%, 0.1%-78.8%, 38.8%-69.9%, 26.6%-65.2%, and 4.2%-39.7%, respectively, and the tomotherapy treatment plan had ranges of 13.6%-100%, 3.5%-100%, 0.4%-94.9%, 0.2%-82.2%, 0.1%-78.5%, and 0.3%-46.3%, respectively. Regarding the NIV for each organ, it is possible to obtain similar values except for the irradiation area of the brain stem. The percentages of NIV 10%, NIV20%, and NIV30%for the brain stem in each patient were 15%-99.8%, 33.4%-100%, and 39.8%-100%, respectively, in the fractionated stereotactic treatment plan and 44.2%-96.5%, 77.7%-99.8%, and 87.8%-100%, respectively, in the tomotherapy treatment plan. In order to achieve higher-quality treatment of intra-cranial tumors, treatment plans should be tailored according to the isodose target volume, inhomogeneous index, conformity index, position of the tumor upon fractionated stereotactic radiosurgery, and radiation

  20. [Role of radiotherapy in the treatment of NK/T-cell nasal type and primary cerebral lymphomas].

    PubMed

    Boros, A; Michot, J-M; Hoang-Xuan, K; Mazeron, R

    2016-10-01

    The head and neck are common sites for extranodal non-Hodgkin lymphomas. Radiotherapy plays an important role in the treatment of low-grade lymphomas, with curative or palliative intent. In the case of high-grade lymphomas, its combination with chemotherapy is debated. Its role is however undeniable in two specific entities: NK/T-cell lymphoma NK/T nasal type, and primary central nervous system lymphomas, which are the subject of this review. PMID:27614517

  1. 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.

  2. 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.

  3. A genetic algorithm for variable selection in logistic regression analysis of radiotherapy treatment outcomes.

    PubMed

    Gayou, Olivier; Das, Shiva K; Zhou, Su-Min; Marks, Lawrence B; Parda, David S; Miften, Moyed

    2008-12-01

    A given outcome of radiotherapy treatment can be modeled by analyzing its correlation with a combination of dosimetric, physiological, biological, and clinical factors, through a logistic regression fit of a large patient population. The quality of the fit is measured by the combination of the predictive power of this particular set of factors and the statistical significance of the individual factors in the model. We developed a genetic algorithm (GA), in which a small sample of all the possible combinations of variables are fitted to the patient data. New models are derived from the best models, through crossover and mutation operations, and are in turn fitted. The process is repeated until the sample converges to the combination of factors that best predicts the outcome. The GA was tested on a data set that investigated the incidence of lung injury in NSCLC patients treated with 3DCRT. The GA identified a model with two variables as the best predictor of radiation pneumonitis: the V30 (p=0.048) and the ongoing use of tobacco at the time of referral (p=0.074). This two-variable model was confirmed as the best model by analyzing all possible combinations of factors. In conclusion, genetic algorithms provide a reliable and fast way to select significant factors in logistic regression analysis of large clinical studies.

  4. A genetic algorithm for variable selection in logistic regression analysis of radiotherapy treatment outcomes

    PubMed Central

    Gayou, Olivier; Das, Shiva K.; Zhou, Su-Min; Marks, Lawrence B.; Parda, David S.; Miften, Moyed

    2008-01-01

    A given outcome of radiotherapy treatment can be modeled by analyzing its correlation with a combination of dosimetric, physiological, biological, and clinical factors, through a logistic regression fit of a large patient population. The quality of the fit is measured by the combination of the predictive power of this particular set of factors and the statistical significance of the individual factors in the model. We developed a genetic algorithm (GA), in which a small sample of all the possible combinations of variables are fitted to the patient data. New models are derived from the best models, through crossover and mutation operations, and are in turn fitted. The process is repeated until the sample converges to the combination of factors that best predicts the outcome. The GA was tested on a data set that investigated the incidence of lung injury in NSCLC patients treated with 3DCRT. The GA identified a model with two variables as the best predictor of radiation pneumonitis: the V30 (p=0.048) and the ongoing use of tobacco at the time of referral (p=0.074). This two-variable model was confirmed as the best model by analyzing all possible combinations of factors. In conclusion, genetic algorithms provide a reliable and fast way to select significant factors in logistic regression analysis of large clinical studies. PMID:19175102

  5. 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.

  6. Estimate of normal tissue damage in treatment planning for stereotactic radiotherapy.

    PubMed

    Benassi, M; Begnozzi, L; Gentile, F P; Chiatti, L; Carpino, S

    1993-10-01

    A personal computer (PC) system was developed to perform treatment planning for radiosurgery and stereotactic radiotherapy. These techniques of irradiation of the brain may be accomplished with a linear accelerator by performing several non-coplanar arcs of a highly collimated beam focused at a fixed point. The PC system allows the acquisition, reconstruction and the visualization of the target volume from CT or MR images, and then it permits to calculate a three-dimensional (3-D) dose distribution due to small photon beams and to visualize it. The software calculates not only total dose distribution, administered fractionated or in single fraction, but also the NTD2 (normalized total dose) predicted to have a biological effect equivalent to the single irradiation. The choice of the best technique is supported by the dose volume histograms (DVH) calculation and by an estimate of complication probability to the brain normal tissue (NTCP). The algorithm for NTCP calculation is based on two models: the linear quadratic and the logistic. A comparison of three different dose calculations for a typical cerebral target volume is presented to demonstrate the system performances.

  7. 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.

  8. 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

  9. [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

  10. 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.

  11. 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

  12. 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

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

    PubMed

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

    2015-07-01

    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 planned

  14. 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.

  15. 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.

  16. Comparison of Short-Course Radiotherapy Versus Long-Course Radiotherapy for Treatment of Metastatic Spinal Cord Compression: A Systematic Review and Meta-Analysis.

    PubMed

    Qu, Song; Meng, Hui-Ling; Liang, Zhong-Guo; Zhu, Xiao-Dong; Li, Ling; Chen, Ling-Xiao; Zhou, Zhi-Rui

    2015-10-01

    In this study, we evaluate the efficacy of short-course radiotherapy (SCRT) versus long-course radiotherapy (LCRT) in the treatment of metastatic spinal cord compression (MSCC).PubMed, EMBASE, and Web of Science were searched up to April 2015. Relevant data were extracted based on inclusion and exclusion criteria. Methodological quality of randomized controlled trial (RCT) was evaluated using modified Jadad scale; non-RCT was evaluated using Newcastle-Ottawa Scale. Meta-analysis was performed using RevMan 5.3 software.Fourteen studies with 2239 patients were included. Results of meta-analysis showed that there were no significant differences between SCRT and long-course radiotherapy LCRT in 6-month overall survival rate (risk ratio [RR] = 0.97, 95% confidence interval [CI] 0.88, 1.07, P = 0.55), 1-year overall survival rate (RR = 0.94, 95% CI 0.85, 1.04, P = 0.22), motor function improvement (RR = 0.96, 95% CI 0.81, 1.13, P = 0.63), no change on motor function (RR = 0.98, 95% CI (0.88, 1.09), P = 0.74], and deterioration on motor function (RR = 0.96, 95% CI 0.71, 1.31, P = 0.78). Compared with SCRT, LCRT significantly increased 6-month local control rate (RR = 0.87, 95% CI 0.80, 0.95, P = 0.002), 1-year local control rate (RR = 0.83, 95% CI 0.71, 0.97, P = 0.02), and 2-year local control rate (RR = 0.83, 95% CI 0.79, 0.87, P < 0.00001).Both LCRT and SCRT provided similar survival rates and functional outcome, but LCRT showed better local control rates than SCRT. However, considering low cost and good patient's compliance, SCRT may be a better choice.

  17. [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

  18. 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.

  19. 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.

  20. Malignant obstructive jaundice: treatment with external-beam and intracavitary radiotherapy

    SciTech Connect

    Johnson, D.W.; Safai, C.; Goffinet, D.R.

    1985-02-01

    Eleven patients with obstructive jaundice from unresectable cholangiocarcinoma, metastatic porta hepatis adenopathy, or direct compression from a pancreatic malignancy were treated at the Stanford University Medical Center from 1978-1983 with an external drainage procedure followed by high-dose external-beam radiotherapy and by an intracavitary boost to the site of obstruction with Iridium/sup 192/ (Ir/sup 192/). A median dose of 5000 cGy was delivered with 4-6 Mv photons to the tumor bed and regional lymphatics in 9 patients, 1 patient received 2100 cGy to the liver in accelerated fractions because of extensive intrahepatic disease, and 1 patient received 7000 equivalent cGy to his pancreatic tumor bed and regional lymphatics with neon heavy particles. An Ir/sup 192/ wire source later delivered a 3100-10,647 cGy boost to the site of biliary obstruction in each patient, for a mean combined dose of 10,202 cGy to a point 5 mm from the line source. Few acute complications were noted, but 3/11 patients (27%) subsequently developed upper gastrointestinal bleeding from duodenitis or frank duodenal ulceration 4 weeks, 4 months, and 7.5 months following treatment. Eight patients died - 5 with local recurrence +/- distant metastasis, 2 with sepsis, and 1 with widespread systemic metastasis. Autopsies revealed no evidence of biliary tree obstruction in 3/3 patients. Evolution of radiation treatment technqiues for biliary obstruction in the literature is reviewed. High-dose external-beam therapy followed by high-dose Ir/sup 192/ intracavitary boost is well tolerated and provides significant palliation.

  1. 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.

  2. [Treatment of pelvic recurrences of carcinoma of the cervix uteri by radiotherapy alone].

    PubMed

    Bignardi, M; Bardelli, D; Bertoni, F; Tordiglione, M

    1988-05-01

    The best way to treat locally recurrent carcinoma of the uterine cervix has not been established. Our retrospective study refers to 37 consecutive patients, with recurrence in the pelvis, treated by radiotherapy alone. Thirty patients were treated by external beam therapy alone; intracavitary brachytherapy alone was adopted in 3 patients and a combination of both techniques in 4 patients. The total radiation dose exceeded 60 Gy in 62% of cases. A complete clinical response was observed in 54% of patients and a partial response in 32.4%. Overall crude survival was 70.3%, 28.9% and 23.2% at 1, 3 and 5 years respectively. In patients with recurrent tumors less than 40 mm in diameter a threefold 3-year survival was achieved (48.6% vs. 14.5%, p less than 0.025). With total doses higher than 60 Gy the 3-year survival resulted to be far better than with lower doses (39.1% vs. 10%, p less than 0.025). A significant advantage was also observed in the "complete responders" group (44% vs. 11.8%), but this difference can be explained by the link between response and the above-mentioned basic prognostic factors. Acute side effects and late complications were moderate and did not correlate with the type of primary treatment. A significant percentage (about 25%) of patients with locally recurrent cervix carcinoma may reach medium-term survival; better results can be achieved in selected groups with favourable prognostic factors and with adequate radiotherapeutic treatment.

  3. Abnormal Nuclear Variations in Response to Radiotherapy- As a Tool in Treatment Planning and Assessment of Prognosis

    PubMed Central

    Naithani, Manisha; Kaur, Sohinder; Reddy, K.S.; Pasi, Rachna

    2016-01-01

    Introduction The treatment approaches for oral squamous cell carcinoma (OSCC) include single management with surgery, radiotherapy, along with chemotherapy or various combinations of these modalities. The estimation of radio sensitivity of individual tumours is essential for planning the optimum radiation schedule for each patient. Assessment of radiation induced histo morphological changes in the nucleus is a known marker of radiosensitivity. Aim The aim of this study was to establish the relationship between nuclear changes with radiation dose and to investigate the prospect of utilizing them as an assay to predict tumour response to radiotherapy in oral cancers. Materials and Methods The present study included 50 patients (age range of 30-65yrs) with histopathologically confirmed squamous cell carcinoma of oral mucosa and being treated by radiotherapy alone with a radiation dose schedule of 4, 14, 24 and 60 Gy respectively at 2nd, 7th, 12th and 30th day. From the included patients, smear of the buccal mucosa was collected and was air dried and fixed with methanol. The Nuclear changes of Micronucleus (MN), Nuclear Budding (NB) and Multinucleation (MNU) were evaluated under the bright field microscopy after staining with Giemsa and May-Grunwald’s stain. Results Out of the 50, 37(74%) were males and 13(26%) were females (Ratio 3:1). The mean percentage increase of MN and MNU were found to be statistically significant (p=0.001) when compared with pre-treatment day. Similar findings were seen with NB, except between pretreatment and after 14 Gy (p-0.110). In the present study the measurement of relative increment index done in respect to all nuclear abnormalities show a sustained increase with increasing dosage of radiation. Conclusion The present study, was undertaken to explore the possibility of establishing a relationship between the frequencies of nuclear abnormalities in patients with oral cancer with applied dosage and duration of radiotherapy. The

  4. P17.70CAN ELDERLY PATIENTS WITH GLIOBLASTOMA BENEFIT FROM CONVENTIONAL CHEMO-RADIOTHERAPY TREATMENT?

    PubMed Central

    Pineda, E.; Valduvieco, I.; Pujol, T.; Oleaga, L.; Ribalta, T.; Caral, L.; Gonzalez, J.; Boget, T.; Graus, F.; Verger, E.

    2014-01-01

    BACKGROUND: Glioblastoma (GBM) is the most life-threatening primary brain tumor, especially in elderly. Despite aggressive treatment, median survival among all GBM patients is only 12-15 months and is worse in elderly (6-9 months). The standard of care for elderly remains controversial. The purpose of this study is to assess the benefit of conventional treatment (Stupp regimen) in elderly patients. METHOD: We retrospectively reviewed a prospective database of 209 patients who were diagnosed with GBM at a single center from January 2005 to March 2013. All patients were divided into younger and elderly groups based on the cut-off age of 65 years. RESULTS: Of 209 patients diagnosed with GBM, 122 (58%) patients were younger than 65 years, and 87 (42%) patients were 65 years old or older. No differences were found in basal patient characteristics and neither in grade of resection between age subgroups. However elderly received less active treatment, radio-chemotherapy was less frequent in elderly (51% vs 73%) but radiotherapy alone (18% vs 8%) and non-oncological treatment after surgery was more frequent in elderly (31% vs 18%) (p = 0.002). No differences in median survival were found in elderly patients who received the same approach treatment than young patients. Median OS was 10.8 months in all GBM patients, 8.7 months in older and 13.6 months in younger patients (p = 0.019). Of all, 106 (51%) patients received Stupp regimen, 41 (47%) elderly and 65 (53%) young. Median OS in patients treated with conventional treatment was 18 months, without differences by age, 15.3 months in older and 18 months in younger (p = 0.228), neither differences were found in PFS (global of 8.2 months, 9.7 and 8.2 months, p = 0.307). MGMT status information was available only for 45.5% of patients that received Stupp regimen, 23 MGMT methylated, 25 MGMT unmethylated and 58 patients with MGMT not evaluable or not done. Surprisingly, no differences in OS were found between groups by MGMT

  5. 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.

  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.

  7. [The role of simultaneous chemotherapy and radiotherapy in the treatment of locally metastasised tumours of the larynx, pharynx and oral cavity].

    PubMed

    Balm, A J M; Schornagel, J H; Rasch, C R N

    2005-01-01

    In The Netherlands each year there are 2300 new patients with a squamous-cell carcinoma of the larynx, pharynx and oral cavity, and of these, one-third has a locally regionally advanced tumour. An operation can then lead to an unacceptable loss of function, whilst radiotherapy alone has no effect on survival. Compared to radiotherapy alone, the combination of radiotherapy and chemotherapy containing cisplatin, when administered simultaneously, produces a higher percentage of patients with loco-regional control and a higher 3-year survival percentage. This improvement in treatment results is accompanied by an increased acute toxicity.

  8. 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.

  9. 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.

  10. Adjunctive radiotherapy with strontium-90 in the treatment of conjunctival squamous cell carcinoma

    SciTech Connect

    Kearsley, J.H.; Fitchew, R.S.; Taylor, R.G.

    1988-03-01

    Squamous cell carcinoma of the ocular conjunctiva is a relatively rare malignancy which is attended by a high rate of local recurrence following simple surgical excision. To date, the management of conjunctival squamous cell cancer has been controversial. From 1950 to 1985, 146 consecutive patients with superficial conjunctival squamous cell cancer were treated at the Queensland Radium Institute. All patients were treated by simple surgical excision of the visible conjunctival lesion followed by adjunctive radiotherapy. Of 140 patients with histologically confirmed squamous cell cancer, 123 were treated with a strontium-90 source, 10 with a radon ring, and 7 with superficial X ray therapy. Standard policy since 1960 has been to deliver an incident dose of 30 Gy in a single fraction within the first 48 post-operative hours to the surgical bed using a strontium-90 source on a stand-off eye applicator. This report will largely focus on the 123 patients who were treated with a strontium-90 source, of whom 107 received 30 Gy, 14 received 40 Gy (pre 1960) and one patient each received 20 and 25 Gy incident dose. Of 131 evaluable patients, there were only 3 who developed local recurrence. All 3 local recurrences developed in elderly men who had presented with extensive superficial primary tumors. Two of the three recurrences occurred in the two patients who were treated with doses less than 30 Gy. Both early and late radiation-induced complications following ablative surgery and treatment with strontium-90 were very uncommon. Three patients developed unsightly conjunctival telangiectasia, 2 patients developed a persistent scleral ulcer and 2 patients developed clinically significant cataracts.

  11. A Multiplan Treatment-Planning Framework: A Paradigm Shift for Intensity-Modulated Radiotherapy

    SciTech Connect

    Meyer, Robert R.; Zhang, Hao H.; Goadrich, Laura; Nazareth, Daryl P.; Shi Leyuan; D'Souza, Warren D. . E-mail: wdsou001@umaryland.edu

    2007-07-15

    Purpose: To describe a multiplan intensity-modulated radiotherapy (IMRT) planning framework, and to describe a decision support system (DSS) for ranking multiple plans and modeling the planning surface. Methods and Materials: One hundred twenty-five plans were generated sequentially for a head-and-neck case and a pelvic case by varying the dose-volume constraints on each of the organs at risk (OARs). A DSS was used to rank plans according to dose-volume histogram (DVH) values, as well as equivalent uniform dose (EUD) values. Two methods for ranking treatment plans were evaluated: composite criteria and pre-emptive selection. The planning surface determined by the results was modeled using quadratic functions. Results: The DSS provided an easy-to-use interface for the comparison of multiple plan features. Plan ranking resulted in the identification of one to three 'optimal' plans. The planning surface models had good predictive capability with respect to both DVH values and EUD values and generally, errors of <6%. Models generated by minimizing the maximum relative error had significantly lower relative errors than models obtained by minimizing the sum of squared errors. Using the quadratic model, plan properties for one OAR were determined as a function of the other OAR constraint settings. The modeled plan surface can then be used to understand the interdependence of competing planning objectives. Conclusion: The DSS can be used to aid the planner in the selection of the most desirable plan. The collection of quadratic models constructed from the plan data to predict DVH and EUD values generally showed excellent agreement with the actual plan values.

  12. 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.

  13. 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

  14. Introducing therapeutic lasers in the hospitals and treatment rooms in Romania

    NASA Astrophysics Data System (ADS)

    Siposan, Dan G.; Manastireanu, Dan I.

    2005-11-01

    Background: Presently, there is no unanimous consensus regarding the methods to introduce laser therapy, on a large scale, into a medical assistance system. These methods may vary from one country to another, depending on some factors. Although, there are some compulsory stages that must be reached. Purpose: This paper's purpose is to present the necessary stages, in our opinion, to successfully introduce laser therapy in hospitals and treatment rooms in our country. They include, among others: an information of the public at large, by brochures or other informative materials, on therapeutic lasers' action; the introducing in high level medicine schools of courses on the biological action of low-level lasers; laboratory studies on action mechanisms of low level laser radiation on live tissues; establishing the more objective methods of patients' assessment; obtaining approval from the Bioethics Committee for clinical studies on volunteers, according to current legislation. Materials and methods: There had been done a preliminary clinical study on volunteers (over 100 in number), using mainly subjective methods of evaluation. The patients have been also monitored also after the treatment, during one to six months. We present briefly a method of monitoring and objective assessment, by optical means, for laser therapy results, which we intend to use in the near future. Results:-There are presented the stages we reached till now. In the preliminary clinical study we have treated patients with various pathologies: skin diseases, dental, surgical and neuralgic pathology etc. We observed an amelioration or total remission on the most patients and also a good mood after the treatments. There are presented a few cases with significant results. Discussion and conclusion: We estimate the success rate of our treatments with over 60 percents. We hope this study shall be useful for the purpose mentioned in the paper's title. In a country where living standard is low, laser

  15. [Evaluation of Radiation Dose during Stent-graft Treatment Using a Hybrid Operating Room System].

    PubMed

    Haga, Yoshihiro; Chida, Kouichi; Kaga, Yuji; Saitou, Kazuhisa; Arai, Takeshi; Suzuki, Shinichi; Iwaya, Yoshimi; Kumasaka, Eriko; Kataoka, Nozomi; Satou, Naoto; Abe, Mitsuya

    2015-12-01

    In recent years, aortic aneurysm treatment with stent graft grafting in the X-ray fluoroscopy is increasing. This is an endovascular therapy, because it is a treatment which includes the risk of radiation damage, having to deal with radiation damage, to know in advance is important. In this study, in order to grasp the trend of exposure stent graft implantation in a hybrid operating room (OR) system, focusing on clinical data (entrance skin dose and fluoroscopy time), was to count the total. In TEVAR and EVAR, fluoroscopy time became 13.40 ± 7.27 minutes, 23.67 ± 11.76 minutes, ESD became 0.87 ± 0.41 mGy, 1.11 ± 0.57 mGy. (fluoroscopy time of EVAR was 2.0 times than TEVAR. DAP of EVAR was 1.2 times than TEVAR.) When using the device, adapted lesions and usage are different. This means that care changes in exposure-related factors. In this study, exposure trends of the stent graft implantation was able to grasp. It can be a helpful way to reduce/optimize the radiation dose in a hybrid OR system.

  16. 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.

  17. 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.

  18. 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

  19. 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

  20. Serial megavoltage CT imaging during external beam radiotherapy for non-small-cell lung cancer: Observations on tumor regression during treatment

    SciTech Connect

    Kupelian, Patrick A. . E-mail: kupelian@orhs.org; Ramsey, Chester; Meeks, Sanford L.; Willoughby, Twyla R.; Forbes, Alan; Wagner, Thomas H.; Langen, Katja M.

    2005-11-15

    Purpose: The ability to obtain soft-tissue imaging in the treatment room, such as with megavoltage CT imaging, enables the observation of tumor regression during a course of external beam radiation therapy. In this current study, we report on the most extensive study looking at the rate of regression of non-small-cell lung cancers during a course of external beam radiotherapy by analyzing serial megavoltage CT images obtained on 10 patients. Methods and Materials: The analysis is performed on 10 patients treated with the Helical Tomotherapy Hi*Art device. All 10 patients had non-small-cell lung cancer. A total of 274 megavoltage CT sets were obtained on the 10 patients (average, 27 scans per patient; range, 9-35). All patients had at least a scan at beginning and at the end of treatment. The frequency of scanning was determined by the treating physician. The treatment was subsequently delivered with the Tomotherapy Hi*Art system. The gross tumor volumes (GTVs) were later contoured on each megavoltage CT scan, and tumor volumes were calculated. Although some patients were treated to draining nodal areas in addition to the primary tumor, only the primary GTVs were tracked. Response to treatment was quantified by the relative decrease in tumor volume over time, i.e., elapsed days from the first day of therapy. The individual GTVs ranged from 5.9 to 737.2 cc in volume at the start of treatment. In 6 of the 10 patients, dose recalculations were also performed to document potential variations in delivered doses within the tumors. The megavoltage CT scans were used, and the planned treatment was recalculated on the daily images. The hypothesis was that dose deposited in the target would increase throughout the course of radiotherapy because of tumor shrinkage and subsequent decreasing attenuation. Specifically, the dose received by 95% of the GTV (D{sub 95}) was monitored over time for each of the 6 patients treated at M.D. Anderson Cancer Center Orlando. Results

  1. 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

  2. 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.

  3. Photon energy-modulated radiotherapy: Monte Carlo simulation and treatment planning study

    SciTech Connect

    Park, Jong Min; Kim, Jung-in; Heon Choi, Chang; Chie, Eui Kyu; Kim, Il Han; Ye, Sung-Joon

    2012-03-15

    Purpose: To demonstrate the feasibility of photon energy-modulated radiotherapy during beam-on time. Methods: A cylindrical device made of aluminum was conceptually proposed as an energy modulator. The frame of the device was connected with 20 tubes through which mercury could be injected or drained to adjust the thickness of mercury along the beam axis. In Monte Carlo (MC) simulations, a flattening filter of 6 or 10 MV linac was replaced with the device. The thickness of mercury inside the device varied from 0 to 40 mm at the field sizes of 5 x 5 cm{sup 2} (FS5), 10 x 10 cm{sup 2} (FS10), and 20 x 20 cm{sup 2} (FS20). At least 5 billion histories were followed for each simulation to create phase space files at 100 cm source to surface distance (SSD). In-water beam data were acquired by additional MC simulations using the above phase space files. A treatment planning system (TPS) was commissioned to generate a virtual machine using the MC-generated beam data. Intensity modulated radiation therapy (IMRT) plans for six clinical cases were generated using conventional 6 MV, 6 MV flattening filter free, and energy-modulated photon beams of the virtual machine. Results: As increasing the thickness of mercury, Percentage depth doses (PDD) of modulated 6 and 10 MV after the depth of dose maximum were continuously increased. The amount of PDD increase at the depth of 10 and 20 cm for modulated 6 MV was 4.8% and 5.2% at FS5, 3.9% and 5.0% at FS10 and 3.2%-4.9% at FS20 as increasing the thickness of mercury from 0 to 20 mm. The same for modulated 10 MV was 4.5% and 5.0% at FS5, 3.8% and 4.7% at FS10 and 4.1% and 4.8% at FS20 as increasing the thickness of mercury from 0 to 25 mm. The outputs of modulated 6 MV with 20 mm mercury and of modulated 10 MV with 25 mm mercury were reduced into 30%, and 56% of conventional linac, respectively. The energy-modulated IMRT plans had less integral doses than 6 MV IMRT or 6 MV flattening filter free plans for tumors located in the

  4. 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

  5. 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.

  6. 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.

  7. Successful treatment of POEMS syndrome with bortezomib and dexamethasone, combined with radiotherapy, and followed by autologous stem cell transplantation.

    PubMed

    Ishii, Yoshimi; Yamazaki, Etsuko; Ishiyama, Yasufumi; Yamamoto, Eri; Hattori, Yukako; Hagihara, Maki; Tomita, Naoto; Ishigatsubo, Yoshiaki

    2013-12-01

    POEMS syndrome is a monoclonal plasma cell disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes. High-dose therapy (HDT) and autologous stem cell transplantation (ASCT) are an effective therapy, but optimal treatment options are still under debate. Bortezomib is an important agent for the treatment of patients with multiple myeloma and has recently been reported as efficacious in the treatment of patients with POEMS syndrome. We present a case of POEMS syndrome in a 33-year-old woman, who was successfully treated with BorDex (bortezomib and dexamethasone) combined with radiotherapy, and followed by ASCT. She was diagnosed with POEMS syndrome with a localized plasmacytoma of bone 5 months after her initial symptoms of heart failure. Her Eastern Cooperative Oncology Group (ECOG) performance status was 4. She was first administered BorDex therapy, which was subsequently combined with radiotherapy. Her general condition including heart failure dramatically improved after four cycles of BorDex therapy and radiation, resulting in partial response. After chemoradiotherapy, HDT and ASCT were performed. After treatment, she was able to walk unassisted and her plasma endothelial growth factor (VEGF) level decreased. She did not experience neurotoxicity induced by bortezomib. Bortezomib was well tolerated and we suggest that BorDex therapy followed by HDT and ASCT may be an effective therapy for POEMS syndrome. PMID:24166587

  8. 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.

  9. Successful treatment of POEMS syndrome with bortezomib and dexamethasone, combined with radiotherapy, and followed by autologous stem cell transplantation.

    PubMed

    Ishii, Yoshimi; Yamazaki, Etsuko; Ishiyama, Yasufumi; Yamamoto, Eri; Hattori, Yukako; Hagihara, Maki; Tomita, Naoto; Ishigatsubo, Yoshiaki

    2013-12-01

    POEMS syndrome is a monoclonal plasma cell disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes. High-dose therapy (HDT) and autologous stem cell transplantation (ASCT) are an effective therapy, but optimal treatment options are still under debate. Bortezomib is an important agent for the treatment of patients with multiple myeloma and has recently been reported as efficacious in the treatment of patients with POEMS syndrome. We present a case of POEMS syndrome in a 33-year-old woman, who was successfully treated with BorDex (bortezomib and dexamethasone) combined with radiotherapy, and followed by ASCT. She was diagnosed with POEMS syndrome with a localized plasmacytoma of bone 5 months after her initial symptoms of heart failure. Her Eastern Cooperative Oncology Group (ECOG) performance status was 4. She was first administered BorDex therapy, which was subsequently combined with radiotherapy. Her general condition including heart failure dramatically improved after four cycles of BorDex therapy and radiation, resulting in partial response. After chemoradiotherapy, HDT and ASCT were performed. After treatment, she was able to walk unassisted and her plasma endothelial growth factor (VEGF) level decreased. She did not experience neurotoxicity induced by bortezomib. Bortezomib was well tolerated and we suggest that BorDex therapy followed by HDT and ASCT may be an effective therapy for POEMS syndrome.

  10. 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

  11. 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…

  12. 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.

  13. Self-Medication: Initial Treatments Used by Patients Seen in an Ophthalmologic Emergency Room

    PubMed Central

    Carvalho, Regina Souza; Kara-José, Newton; Temporini, Edméa Rita; Kara-Junior, Newton; Noma-Campos, Regina

    2009-01-01

    OJECTIVE This study seeks to identify practices of self-medication in the treatment of ocular emergencies. We examine patients’ use of both homemade preparations and manufactured products before seeking specialized care. MATERIALS AND METHODS We conducted a cross-sectional analytic survey of consecutive patients seen in the ophthalmology emergency room of a teaching hospital. RESULTS The sample included 561 subjects, 51.3% males and 48.7% females, with a mean age of 39.8 years. Prior to seeking emergency care, 40.5% reported self-medicating; 29.4% used a homemade preparation (13.9% referred to an industrialized product like boric acid as a homemade preparation), and 11.1% used a manufactured product. The most frequently used products included a boric acid solution (53.3%), a normal saline solution (35.7%), herbal infusions (6.1%) and breast milk (4.8%). Viral conjunctivitis was the most frequent diagnosis (24.4%), followed by the presence of a corneal foreign body (7.4%). No significant differences were found in the self-treatment of ocular injuries according to gender (p = 0.95), level of education (p = 0.21) or age (p = 0.14). In addition, self-medication practices were not related to the medically judged severity of the condition. CONCLUSION Patients often attempt to treat conditions that require ophthalmologic emergency care by self-medicating with homemade or manufactured products. The most widely used products include boric acid, normal saline, leaf infusions and breast milk. This behavior occurs independently of educational level, gender, age or the nature of the ocular condition. Self-medication is a culturally driven practice that is used even in cases of acute ocular injuries. PMID:19690656

  14. 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

  15. 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

  16. Cancer of the larynx--treatment results after primary radiotherapy with salvage surgery in a series of 1005 patients.

    PubMed

    Jørgensen, Karsten; Godballe, Christian; Hansen, Olfred; Bastholt, Lars

    2002-01-01

    The aim of this study is to present and discuss the results of initial radiotherapy with salvage surgery and to compare them with those from centres where primary surgery is the prevailing principle. The series comprised 1005 consecutive patients treated during the period 1965-1998. Salvage surgery was performed if patients had residual tumour or developed recurrence. Disease-specific survival (DSS) and crude survival (CS) after 5 years, among 643 patients with glottic carcinomas treated with curative radiotherapy was 88.6% (SE = 1.3) and 65.3% (SE = 2.0), respectively. Among T1 glottic carcinomas the locoregional control was 88%, i.e. 88% of patients were cured after radiotherapy alone, and the DSS was 99% both evaluated after 5 years, i.e. the salvage surgery added approximately 11% to the survival of T1 glottic patients. Only 4% (12/312) of T1 glottic patients had laryngectomies. Locoregional control among T2 glottic cases was 67% and the DSS 88%, but, 18% (41/233) of patients lost their larynx. The corresponding results among T3 glottic cases were 30% and 59%, i.e. the organ preservation was close to 50%. Among patients with supraglottic carcinomas, the two estimates were 440 and 63%, respectively. Compared with our results, recent results published in the literature after initial laser surgery of T1 glottic carcinomas indicate that there are only minor differences in DSS and organ preservation, but it is generally agreed, but not proven, that voice quality after radiotherapy is better. T2 glottic carcinomas treated by initial supracricoid partial laryngectomy in a selected series have yielded very high DSS rates with better organ preservation than was observed in the present series. As to T3 glottic carcinomas, initial surgery does not produce better survival rates than those produced in the present series but our organ preservation is higher. The treatment of patients with supraglottic carcinoma has benefited from optimization of radiotherapy during recent

  17. Microbial surface contamination after standard operating room cleaning practices following surgical treatment of infection.

    PubMed

    Balkissoon, Rishi; Nayfeh, Tariq; Adams, Kerri L; Belkoff, Stephen M; Riedel, Stefan; Mears, Simon C

    2014-04-01

    At the authors' institution, some joint arthroplasty surgeons require the operating room to be terminally cleaned before using the room after infected cases, in theory to decrease exposure to excessive microbial contamination for the subsequent patient. The authors found no guidance in the literature to support this practice. To test this theory, the authors measured microbial surface contamination from 9 surfaces in operating rooms after standard operating room turnover following 14 infected cases vs 16 noninfected cases. A check was made for an association between organisms isolated intraoperatively from infected surgical patients immediately preceding standard cleaning and organisms isolated from common operating room surfaces. Colony counts were made at 24 and 48 hours, and organisms were identified. No significant difference was noted in colony counts between infected and noninfected cases, and no relationship was found between organisms isolated from infected cases and those from operating room surfaces. Furthermore, the largest colony count from both groups (0.08 cfu/cm(2)) was an order of magnitude less than the recently proposed 5 cfu/cm(2) threshold for surface hygiene in hospitals. This finding indicates that standard operating room turnover results in minimal surface contamination, regardless of the previous case's infection status, and that there is no need for a more extensive terminal cleaning after an infected case.

  18. Choroidal metastases in testicular choriocarcinoma, successful treatment with chemo- and radiotherapy: a case report

    PubMed Central

    2011-01-01

    Background Choriocarcinoma is a very rare cause of ocular metastasis. Only 18 male patients have been reported on, 4 of whom survived, but with significant loss of vision. Case presentation A 26-year-old Caucasian man, suffering from testicular choriocarcinoma with pulmonary, cerebral, renal, hepatic and osseous metastases, underwent left radical orchiectomy. While being treated with chemotherapy, he presented with loss of vision in the left eye. Ophthalmoscopy revealed bilateral non-pigmented, hemorrhagic choroidal tumours, compatible with secondary lesions. Continued chemotherapy and stereotactic radiotherapy of the skull and spine lead to full remission with excellent vision, after more than 4 years of follow up. Conclusion Testicular choriocarcinoma is an exceptional cause of choroidal metastasis, potentially asymptomatic and with specific clinical features. Radiotherapy can complement radical orchiectomy and chemotherapy, to achieve full remission and maintain good vision. PMID:22151977

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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

  6. The UK Standardisation of Breast Radiotherapy (START) Trial A of radiotherapy hypofractionation for treatment of early breast cancer: a randomised trial

    PubMed Central

    2008-01-01

    Summary Background The international standard radiotherapy schedule for breast cancer treatment delivers a high total dose in 25 small daily doses (fractions). However, a lower total dose delivered in fewer, larger fractions (hypofractionation) is hypothesised to be at least as safe and effective as the standard treatment. We tested two dose levels of a 13-fraction schedule against the standard regimen with the aim of measuring the sensitivity of normal and malignant tissues to fraction size. Methods Between 1998 and 2002, 2236 women with early breast cancer (pT1-3a pN0-1 M0) at 17 centres in the UK were randomly assigned after primary surgery to receive 50 Gy in 25 fractions of 2·0 Gy versus 41·6 Gy or 39 Gy in 13 fractions of 3·2 Gy or 3·0 Gy over 5 weeks. Women were eligible if they were aged over 18 years, did not have an immediate surgical reconstruction, and were available for follow-up. Randomisation method was computer generated and was not blinded. The protocol-specified principal endpoints were local-regional tumour relapse, defined as reappearance of cancer at irradiated sites, late normal tissue effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN59368779. Findings 749 women were assigned to the 50 Gy group, 750 to the 41·6 Gy group, and 737 to the 39 Gy group. After a median follow up of 5·1 years (IQR 4·4–6·0) the rate of local-regional tumour relapse at 5 years was 3·6% (95% CI 2·2–5·1) after 50 Gy, 3·5% (95% CI 2·1–4·3) after 41·6 Gy, and 5·2% (95% CI 3·5–6·9) after 39 Gy. The estimated absolute differences in 5-year local-regional relapse rates compared with 50 Gy were 0·2% (95% CI −1·3% to 2·6%) after 41·6 Gy and 0·9% (95% CI −0·8% to 3·7%) after 39 Gy. Photographic and patient self-assessments suggested lower rates of late adverse effects after 39 Gy than with 50 Gy, with an HR for late change in

  7. RADIATION DOSIMETRY IN THE BNCT PATIENT TREATMENT ROOM AT THE BMRR.

    SciTech Connect

    HOLDEN, N.E.; RECINIELLO, R.N.; HU, J.-P.

    2005-05-08

    The Medical Research Reactor at the Brookhaven National Laboratory (BMRR) was a heterogeneous, tank type, light water cooled and moderated, graphite reflected reactor, which was operated on demand at a power level up to 3 mega-watts (MW) for medical and biological research [1]. The reactor first went critical on March 15, 1959, with 17 fresh fuel elements (2.52 kg uranium-235 in a total of 2.7 kg uranium) in the center core. The BMRR had two treatment rooms on opposite sides of the core. It had a predominately thermal neutron beam in the Thermal Neutron Irradiation Facility (TNE) on the west side of the core. By early 1990, a redesigned beam line had a predominately epithermal neutron beam in the Epithermal Neutron Irradiation Facility (ENIF) on the east side of the core [2]. The ENP was approximately 11 feet by 21 feet in size with its focal point consisting of a bismuth plate mounted in the wall adjacent to the reactor shield about 36 inches above the floor. The beam originated at a shutter constructed of 0.75 inch steel filled with concrete and weighing {approx}21 tons. Access to the ENIF was through a pair of hand operated steel shielding doors, each 42 inches wide, 84 inches high and 5 inches thick. The inner door had a 4-inch thick layer of paraffin on the side facing the reactor. The doors 5000 pounds weighed each. Additional shielding material had been added to the entire beam port at reactor wall within the ENIF. The shielding material consisted of 2-inch thick polyethylene sheets, which were impregnated with 95%-enriched {sup 6}Li in lithium carbonate (Li{sub 2}CO{sub 3}). The shielding sheets around the port face were designed to allow the insertion of a variety of different beam collimators.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. Results of treatment intensification for progressive locoregional disease in head-and-neck cancer patients undergoing postoperative radiotherapy

    SciTech Connect

    Corry, June . E-mail: June.Corry@petermac.org; Rischin, Danny; Mukesh, Bickol N.; Porceddu, Sandro; Peters, Lester J.

    2005-04-01

    Purpose: Patients who develop progressive locoregional disease during radical surgery and postoperative radiotherapy for squamous cell carcinoma of the head and neck represent a management dilemma. We present our experience using treatment intensification for such patients. Methods and materials: A prospective record of eligible patients was kept between May 1998 and December 2001. The study included 15 patients, 11 men and 4 women (median age, 60 years); 67% had Stage III-IV disease. The sites of progression were primary in 3, nodes/scar in 10, and both primary and nodes in 2. Relative to the initial plan, treatment intensification was achieved by an increased radiation dose in 7 (using accelerated fractionation in 5), an increased radiation dose and the addition of concomitant chemotherapy in 7, and the addition of concomitant chemotherapy alone in 1 patient. Results: The median follow-up was 40 months. Eight patients had a complete response to intensified treatment. At the closeout date, 6 patients were alive with no evidence of disease. Eight patients had died with locoregional disease; two also had distant metastases. One patient was lost to follow-up after achieving a complete response. The median failure-free survival for all patients was 6 months, but for those with a complete response, it was 37 months. The median overall survival time was 28 months. The 2-year and 3-year overall survival rate was 50% and 42%, respectively. Acute mucosal and skin toxicity was increased relative to standard postoperative radiotherapy but was not dissimilar to that expected after radical definitive chemoradiotherapy. Conclusion: Intensification of treatment in patients who develop progressive locoregional disease is warranted, because it can lead to long-term disease control in a subset of patients with significant but acceptable toxicity.

  14. 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

  15. 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.

  16. Increased beam attenuation and surface dose by different couch inserts of treatment tables used in megavoltage radiotherapy.

    PubMed

    Seppälä, Jan K H; Kulmala, Jarmo A J

    2011-11-15

    The use of solid carbon fiber table materials in radiotherapy has become more common with the implementation of image-guided radiotherapy (IGRT), since the solid materials give less imaging artifacts than the so-called tennis racket couchtops. The downside of the solid carbon fiber couch inserts is that they increase the beam attenuation, resulting in increased surface doses and inaccuracies in determine the dose in the patient. The purpose of this study was to evaluate the interaction of 6 and 15 MV photons with eight different couch inserts. The presented results enable direct comparison of the attenuation properties of the studied couchtops. With a direct posterior beam the maximum attenuations reach 3.6% and 2.4% with 6 and 15 MV, respectively. The measured maximum attenuation by a couchtop with an oblique gantry angle was 10.8% and 7.4% at 6 and 15 MV energies, respectively. The skin-sparing effect was decreased substantially with every couchtop. The highest increases in surface doses were recorded to be four- and threefold, as compared to the direct posterior open field surface doses of 6 and 15 MV, respectively. In conclusion, the carbon fiber tabletops decrease the skin-sparing effect of megavoltage photon energies. The increased beam attenuation and skin doses should be taken into account in the process of treatment planning.

  17. Design of a beam shaping assembly and preliminary modelling of a treatment room for accelerator-based BNCT at CNEA.

    PubMed

    Burlon, A A; Girola, S; Valda, A A; Minsky, D M; Kreiner, A J; Sánchez, G

    2011-12-01

    This work reports on the characterisation of a neutron beam shaping assembly (BSA) prototype and on the preliminary modelling of a treatment room for BNCT within the framework of a research programme for the development and construction of an accelerator-based BNCT irradiation facility in Buenos Aires, Argentina. The BSA prototype constructed has been characterised by means of MCNP simulations as well as a set of experimental measurements performed at the Tandar accelerator at the National Atomic Energy Commission of Argentina.

  18. 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.

  19. Considerations on the role of chemotherapy and modern radiotherapy in the treatment of childhood low grade glioma.

    PubMed

    Perilongo, Giorgio

    2005-12-01

    The treatment of childhood low grade glioma (LGG), if not amenable to complete resection, quite often is a relevant clinical challenge. LGG in many instances are indeed slow growing tumors, which, if not controlled, can cause severe morbidity and ultimately jeopardize life. Most of the time children bearing an unresectable LGG can be considered affected by a chronic disease, deserving protracted cures. The treatment philosophy, which has dictated the treatment of malignant cancers, has also inspired the therapeutic concepts for managing childhood LGG. However, it is getting more and more evident that different strategies are needed for them. LGG represent a highly heterogeneous group of neoplasm and comprehensive treatment concepts rarely meet the individual patient's needs. After more than 20 years of clinical research it can be stated with confidence that for unresectable, progressive LGG, chemotherapy (CT) represents an effective treatment modality. It delays tumor growth and postpones the use of radiotherapy (RT), thus sparing the deleterious effects of irradiation on a developing brain. However, CT rarely cures LGG and definitively obviates the need of RT or aggressive surgery. Furthermore, little is known on the actual impact of CT on patients' overall health status. Recent progresses in RT delivering techniques, which allow reducing the safety margins, are tempering the concerns related to the use of this treatment modality in children. This manuscript reviews and expands these data, trying to combine them in a coherent picture that it is hoped can help in directing future research in this field.

  20. 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.

  1. Regional Nodal Recurrence After Breast Conservation Treatment With Radiotherapy for Women With Early-Stage Breast Carcinoma

    SciTech Connect

    Lukens, J. Nicholas Vapiwala, Neha; Hwang, W.-T.; Solin, Lawrence J.

    2009-04-01

    Purpose: To report the long-term outcomes for women presenting with regional lymph node recurrence after breast conservation treatment with radiotherapy for Stage I and II invasive breast carcinoma. Methods and Materials: Of the women with pathologic Stage I and II invasive breast carcinoma treated with breast conservation treatment at University of Pennsylvania, 29 developed regional nodal recurrence as their first site of failure. An analysis of the patterns of regional nodal recurrence and their prognosis after recurrence was undertaken. The median follow-up from regional nodal recurrence was 5.4 years. Results: The pattern of regional nodal recurrence was as follows: 14 (48%) with simultaneous local and axillary recurrence, 7 (24%) with recurrence in the axilla only, 5 (17%) with recurrence in the supraclavicular region only, and 3 (10%) with multiple nodal sites of recurrence. For the entire study group, the 5-, 10-, and 15-year overall survival rate was 70%, 37%, and 28%, respectively. The 10-year overall survival rate for patients with locoregional recurrence was 32% compared with 45% for patients with regional-only recurrence (p = 0.50). The 10-year overall survival rate for patients with axillary recurrence discovered on pathologic examination of the mastectomy specimen was 31% compared with 42% for patients with palpable regional lymphadenopathy (p = 0.83). Conclusion: Patients with regional nodal recurrence after breast conservation treatment with radiotherapy for early-stage breast carcinoma are potentially salvageable. The prognosis after regional nodal recurrence was not significantly different when stratified by the presence or absence of simultaneous in-breast recurrence or the method of detection.

  2. 9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... rooms shall be well-lighted and have ceilings and walls of a tile surface, enamel paint, or other water-resistant material. (1) The floors shall be free from cracks or rough surfaces where water or dirt could accumulate. (2) The intersections of the walls and floors shall be impervious to water and the floor shall...

  3. 9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... rooms shall be well-lighted and have ceilings and walls of a tile surface, enamel paint, or other water-resistant material. (1) The floors shall be free from cracks or rough surfaces where water or dirt could accumulate. (2) The intersections of the walls and floors shall be impervious to water and the floor shall...

  4. 9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... rooms shall be well-lighted and have ceilings and walls of a tile surface, enamel paint, or other water-resistant material. (1) The floors shall be free from cracks or rough surfaces where water or dirt could accumulate. (2) The intersections of the walls and floors shall be impervious to water and the floor shall...

  5. 9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... rooms shall be well-lighted and have ceilings and walls of a tile surface, enamel paint, or other water-resistant material. (1) The floors shall be free from cracks or rough surfaces where water or dirt could accumulate. (2) The intersections of the walls and floors shall be impervious to water and the floor shall...

  6. 9 CFR 590.548 - Drying, blending, packaging, and heat treatment rooms and facilities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... rooms shall be well-lighted and have ceilings and walls of a tile surface, enamel paint, or other water-resistant material. (1) The floors shall be free from cracks or rough surfaces where water or dirt could accumulate. (2) The intersections of the walls and floors shall be impervious to water and the floor shall...

  7. 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.

  8. Potential improvement of three dimension treatment planning and proton beams in fractonated radiotherapy of large cerebral arteriovenous malformations

    SciTech Connect

    Miralbell, R.; Urie, M. )

    1993-01-15

    The treatment of large cerebral arteriovenous malformations is a surgical challenge, especially for deep seated brain locations. Furthermore, these lesions are unfit for radiosurgical approaches due to a high risk of complications secondary to high radiation doses to large brain volumes. Fractionated precision radiotherapy can potentially deliver high, uniform, target-contoured dose distributions optimizing the dose reduction to the critical surrounding brain. The results of a study are presented in such a way that dose distributions achievable with proton beams are compared to those with 10 MV x-rays; and the potential improvements with protons evaluated, relying heavily on dose-volume histograms to examine the coverage of the lesion as well as the dose to the normal brain, brain-stem, and optic chiasm.

  9. 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.

  10. 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.

  11. The Utility of Positron Emission Tomography in the Treatment Planning of Image-Guided Radiotherapy for Non-Small Cell Lung Cancer

    PubMed Central

    Chi, Alexander; Nguyen, Nam P.

    2014-01-01

    In the thorax, the extent of tumor may be more accurately defined with the addition of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to computed tomography (CT). This led to the increased utility of FDG-PET or PET/CT in the treatment planning of radiotherapy for non-small cell lung cancer (NSCLC). The inclusion of FDG-PET information in target volume delineation not only improves tumor localization but also decreases the amount of normal tissue included in the planning target volume (PTV) in selected patients. Therefore, it has a critical role in image-guided radiotherapy (IGRT) for NSCLC. In this review, the impact of FDG-PET on target volume delineation in radiotherapy for NSCLC, which may increase the possibility of safe dose escalation with IGRT, the commonly used methods for tumor target volume delineation FDG-PET for NSCLC, and its impact on clinical outcome will be discussed. PMID:25340040

  12. Treatment of Early Stage Non-Small Cell Lung Cancer: Surgery or Stereotactic Ablative Radiotherapy?

    PubMed Central

    Uzel, Esengül Koçak; Abacıoğlu, Ufuk

    2015-01-01

    The management of early-stage Non-small Cell Lung Cancer (NSCLC) has improved recently due to advances in surgical and radiation modalities. Minimally-invasive procedures like Video-assisted thoracoscopic surgery (VATS) lobectomy decreases the morbidity of surgery, while the numerous methods of staging the mediastinum such as endobronchial and endoscopic ultrasound-guided biopsies are helping to achieve the objectives much more effectively. Stereotactic Ablative Radiotherapy (SABR) has become the frontrunner as the standard of care in medically inoperable early stage NSCLC patients, and has also been branded as tolerable and highly effective. Ongoing researches using SABR are continuously validating the optimal dosing and fractionation schemes, while at the same time instituting its role for both inoperable and operable patients. PMID:25759766

  13. 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

  14. 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.

  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. 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.

  17. Volumetric Arc Intensity-Modulated Therapy for Spine Body Radiotherapy: Comparison With Static Intensity-Modulated Treatment

    SciTech Connect

    Wu, Q. Jackie; Yoo, Sua; Kirkpatrick, John P.; Thongphiew, Danthai; Yin Fangfang

    2009-12-01

    Purpose: This clinical study evaluates the feasibility of using volumetric arc-modulated treatment (VMAT) for spine stereotactic body radiotherapy (SBRT) to achieve highly conformal dose distributions that spare adjacent organs at risk (OAR) with reduced treatment time. Methods and Materials: Ten spine SBRT patients were studied retrospectively. The intensity-modulated radiotherapy (IMRT) and VMAT plans were generated using either one or two arcs. Planning target volume (PTV) dose coverage, OAR dose sparing, and normal tissue integral dose were measured and compared. Differences in treatment delivery were also analyzed. Results: The PTV DVHs were comparable between VMAT and IMRT plans in the shoulder (D{sub 99%}-D{sub 90%}), slope (D{sub 90%}-D{sub 10%}), and tail (D{sub 10%}-D{sub 1%}) regions. Only VMAT{sub 2arc} had a better conformity index than IMRT (1.09 vs. 1.15, p = 0.007). For cord sparing, IMRT was the best, and VMAT{sub 1arc} was the worst. Use of IMRT achieved greater than 10% more D{sub 1%} sparing for six of 10 cases and 7% to 15% more D{sub 10%} sparing over the VAMT{sub 1arc}. The differences between IMRT and VAMT{sub 2arc} were smaller and statistically nonsignificant at all dose levels. The differences were also small and statistically nonsignificant for other OAR sparing. The mean monitor units (MUs) were 8711, 7730, and 6317 for IMRT, VMAT{sub 1arc}, and VMAT{sub 2arc} plans, respectively, with a 26% reduction from IMRT to VMAT{sub 2arc}. The mean treatment time was 15.86, 8.56, and 7.88 min for IMRT, VMAT{sub 1arc,} and VMAT{sub 2arc}. The difference in integral dose was statistically nonsignificant. Conclusions: Although VMAT provided comparable PTV coverage for spine SBRT, 1arc showed significantly worse spinal cord sparing compared with IMRT, whereas 2arc was comparable to IMRT. Treatment efficiency is substantially improved with the VMAT.

  18. 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.

  19. An optimization method for importance factors and beam weights based on genetic algorithms for radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Wu, Xingen; Zhu, Yunping

    2001-04-01

    We propose a new method for selecting importance factors (for regions of interest like organs at risk) used to plan conformal radiotherapy. Importance factors, also known as weighting factors or penalty factors, are essential in determining the relative importance of multiple objectives or the penalty ratios of constraints incorporated into cost functions, especially in dealing with dose optimization in radiotherapy treatment planning. Researchers usually choose importance factors on the basis of a trial-and-error process to reach a balance between all the objectives. In this study, we used a genetic algorithm and adopted a real-number encoding method to represent both beam weights and importance factors in each chromosome. The algorithm starts by optimizing the beam weights for a fixed number of iterations then modifying the importance factors for another fixed number of iterations. During the first phase, the genetic operators, such as crossover and mutation, are carried out only on beam weights, and importance factors for each chromosome are not changed or `frozen'. In the second phase, the situation is reversed: the beam weights are `frozen' and the importance factors are changed after crossover and mutation. Through alternation of these two phases, both beam weights and importance factors are adjusted according to a fitness function that describes the conformity of dose distribution in planning target volume and dose-tolerance constraints in organs at risk. Those chromosomes with better fitness are passed into the next generation, showing that they have a better combination of beam weights and importance factors. Although the ranges of the importance factors should be set in advance by using this algorithm, it is much more convenient than selecting specific numbers for importance factors. Three clinical examples are presented and compared with manual plans to verify this method. Three-dimensional standard displays and dose-volume histograms are shown to

  20. Three months' treatment with cyclophosphamide, VP-16-213 followed by methotrexate and thoracic radiotherapy for small cell lung cancer.

    PubMed

    Thatcher, N; James, R D; Steward, W P; Barber, P V; Feinmann, D; Lawson, B A; Carroll, K B

    1985-09-15

    One hundred eleven patients with inoperable but limited-stage small cell lung cancer were treated with three courses of cyclophosphamide (1.5, 2.5, and 3.5 g/m2, respectively) and VP-16-213 followed by methotrexate and thoracic radiotherapy. The total duration of treatment was 3 months. Patients were included who had pleural effusions, contralateral neck nodes, and bone marrow infiltration. The complete response (CR) rate was 56%, the majority confirmed by repeat bronchoscopy, with an 81% overall response rate. The minimum follow-up was 14 months. Median survival for all 111 patients was 11 months and 14 months (1-34+) for complete responders; the median survival was also 11 months for the 91 patients with conventional limited-stage disease, although 15 of the 19 patients alive at 14 months or more were from this subpopulation. There was no significant difference in the survival of those CR patients whose response was confirmed bronchoscopically and patients whose CR was assessed only radiologically and clinically. Forty-four patients with leukopenia (less than 1000 cells/microliter) received intravenous antibiotics for malaise and suspected infection. Close monitoring between treatments and direct access of patients to the hospital was encouraged. The majority of patients improved symptomatically as assessed by Karnofsky and Respiratory scores. These results support the view that short but intensive treatment without long-term or maintenance chemotherapy is beneficial.

  1. 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

  2. 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

  3. In situ vaccination by radiotherapy to improve responses to anti-CTLA-4 treatment.

    PubMed

    Vanpouille-Box, Claire; Pilones, Karsten A; Wennerberg, Erik; Formenti, Silvia C; Demaria, Sandra

    2015-12-16

    Targeting immune checkpoint receptors has emerged as an effective strategy to induce immune-mediated cancer regression in the subset of patients who have significant pre-existing anti-tumor immunity. For the remainder, effective anti tumor responses may require vaccination. Radiotherapy, traditionally used to achieve local tumor control, has acquired a new role, that of a partner for immunotherapy. Ionizing radiation has pro-inflammatory effects that facilitate tumor rejection. Radiation alters the tumor to enhance the concentration of effector T cells via induction of chemokines, cytokines and adhesion molecules. In parallel, radiation can induce an immunogenic death of cancer cells, promoting cross-presentation of tumor-derived antigens by dendritic cells to T cells. Newly generated anti-tumor immune responses have been demonstrated post-radiation in both murine models and occasional patients, supporting the hypothesis that the irradiated tumor can become an in situ vaccine. It is in this role, that radiation can be applied to induce anti-tumor T cells in lymphocyte-poor tumors, and possibly benefit patients who would otherwise fail to respond to immune checkpoint inhibitors. This review summarizes preclinical and clinical data demonstrating that radiation acts in concert with antibodies targeting the immune checkpoint cytotoxic T-lymphocyte antigen-4 (CTLA-4), to induce therapeutically effective anti-tumor T cell responses in tumors otherwise non responsive to anti-CTLA-4 therapy.

  4. 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.

  5. 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.

  6. An optimization model and solution for radiation shielding design of radiotherapy treatment vaults.

    PubMed

    Newman, Francis; Asadi-Zeydabadi, Masoud

    2008-01-01

    In radiation shielding design, one is usually faced with a set of conflicting goals that are navigated by an experienced physicist. If one has abundant space, the task is simplified because concrete is relatively inexpensive and will provide adequate shielding for high energy photons and neutrons, when applicable. However, if space is constrained (which is usually the case), the design becomes more difficult since one will likely have to employ combinations of steel, lead, and concrete, or other new materials--each with different properties and costs. Very experienced shielding designers can draw upon previous plans, but they do not know if their design is optimal in any sense. We have constructed a linear program that minimizes the cost of the shielding materials and minimizes the dose at the protection point or the shielding thickness subject to space constraints and to Federal or State regulations regarding the allowable exposure to individuals adjacent to the radiotherapy vault. In spite of what appears to be a simple model, the solution may require iterations of the optimization to arrive at the optimal solution. PMID:18293573

  7. 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

  8. A Treatment Planning and Acute Toxicity Comparison of Two Pelvic Nodal Volume Delineation Techniques and Delivery Comparison of Intensity-Modulated Radiotherapy Versus Volumetric Modulated Arc Therapy for Hypofractionated High-Risk Prostate Cancer Radiotherapy

    SciTech Connect

    Myrehaug, Sten; Chan, Gordon; Craig, Tim; Weinberg, Vivian; Cheng, Chun; Roach, Mack; Cheung, Patrick; Sahgal, Arjun

    2012-03-15

    Purpose: To perform a comparison of two pelvic lymph node volume delineation strategies used in intensity-modulated radiotherapy (IMRT) for high risk prostate cancer and to determine the role of volumetric modulated arc therapy (VMAT). Methods and Materials: Eighteen consecutive patients accrued to an ongoing clinical trial were identified according to either the nodal contouring strategy as described based on lymphotropic nanoparticle-enhanced magnetic resonance imaging technology (9 patients) or the current Radiation Therapy Oncology Group (RTOG) consensus guidelines (9 patients). Radiation consisted of 45 Gy to prostate, seminal vesicles, and lymph nodes, with a simultaneous integrated boost to the prostate alone, to a total dose of 67.5 Gy delivered in 25 fractions. Prospective acute genitourinary and gastrointestinal toxicities were compared at baseline, during radiotherapy, and 3 months after radiotherapy. Each patient was retrospectively replanned using the opposite method of nodal contouring, and plans were normalized for dosimetric comparison. VMAT plans were also generated according to the RTOG method for comparison. Results: RTOG plans resulted in a significantly lower rate of genitourinary frequency 3 months after treatment. The dosimetric comparison showed that the RTOG plans resulted in both favorable planning target volume (PTV) coverage and lower organs at risk (OARs) and integral (ID) doses. VMAT required two to three arcs to achieve adequate treatment plans, we did not observe consistent dosimetric benefits to either the PTV or the OARs, and a higher ID was observed. However, treatment times were significantly shorter with VMAT. Conclusion: The RTOG guidelines for pelvic nodal volume delineation results in favorable dosimetry and acceptable acute toxicities for both the target and OARs. We are unable to conclude that VMAT provides a benefit compared with IMRT.

  9. Radiotherapy treatment verification using radiological thickness measured with an amorphous silicon electronic portal imaging device: Monte Carlo simulation and experiment

    NASA Astrophysics Data System (ADS)

    Kairn, T.; Cassidy, D.; Sandford, P. M.; Fielding, A. L.

    2008-07-01

    This work validates the use of an amorphous-silicon, flat-panel electronic portal imaging device (a-Si EPID) for use as a gauge of patient or phantom radiological thickness, as an alternative to dosimetry. The response of the a-Si EPID is calibrated by adapting a technique previously applied to scanning liquid ion chamber EPIDs, and the stability, accuracy and reliability of this calibration are explored in detail. We find that the stability of this calibration, between different linacs at the same centre, is sufficient to justify calibrating only one of the EPIDs every month and using the calibration data thus obtained to perform measurements on all of the other linacs. Radiological thickness is shown to provide a reliable means of relating experimental measurements to the results of BEAMnrc Monte Carlo simulations of the linac-phantom-EPID system. For these reasons we suggest that radiological thickness can be used to verify radiotherapy treatment delivery and identify changes in the treatment field, patient position and target location, as well as patient physical thickness.

  10. 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.

  11. [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

  12. 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.

  13. Thermal neutron fluence in a treatment room with a Varian linear accelerator at a medical university hospital

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Shan; Changlai, Sheng-Pin; Pan, Lung-Kwang; Tseng, Hsien-Chun; Chen, Chien-Yi

    2011-09-01

    The indium foil activation technique has been employed to measure thermal neutron fluences ( Φth) among various locations in the treatment room with a 20×20 cm 2 field size and a 15 and 10 MV X-ray beam. Spatial Φth are visualized using colored three-dimensional graphical representations; intensities are up to (1.97±0.13)×10 5 and (1.46±0.13)×10 4 n cm -2/Gy-X at isocenter, respectively. The Φth is found to increase with the X-ray energy of the LINAC and decreases as it moves away from the beam center. However, thermal neutron exposure is not assessed in routine dosimetry planning and radiation assessment of patients since neutron dose contributes <1% of the given therapy dose. However, unlike the accelerated beam limited within the gantry window, photoneutrons are widely spread in the treatment room. Distributions of Φth were measured in water phantom irradiated with 15 MV X-ray beams. The shielding effect of the maze was also evaluated. The experimentally estimated Φth along the maze distance was fitted explicate and the tenth-value layer (TVL) was calculated and discussed. Use of a 10 cm-thick polyethylene door placed at the maze was suitable for radiation shielding.

  14. Predicting Rectal and Bladder Overdose During the Course of Prostate Radiotherapy Using Dose-Volume Data From Initial Treatment Fractions

    SciTech Connect

    Murthy, Vedang; Shukla, Pragya; Adurkar, Pranjal; Master, Zubin; Mahantshetty, Umesh; Shrivastava, Shyamkishore

    2012-09-01

    Purpose: To evaluate whether information from the initial fractions can determine which patients are likely to consistently exceed their planning dose-volume constraints during the course of radiotherapy for prostate cancer. Methods and Materials: Ten patients with high-risk prostate cancer were treated with helical tomotherapy to a dose of 60 Gy in 20 fractions. The prostate, rectum, and bladder were recontoured on their daily megavoltage computed tomography scans and the dose was recalculated. The bladder and rectal volumes (in mL) receiving {>=}100% and {>=}70% of the prescribed dose in each fraction and in the original plans were recorded. A fraction for which the difference between planned and delivered was more than 2 mL was considered a volume failure. Similarly if the difference in the planned and delivered maximum dose (D{sub max}) was {>=}1% for the rectum and bladder, the fraction was considered a dose failure. Each patient's first 3 to 5 fractions were analyzed to determine if they correctly identified those patients who would consistently fail (i.e., {>=}20% of fractions) during the course of their radiotherapy. Results: Six parameters were studied; the rectal volume (RV) and bladder volumes (BV) (in mL) received {>=}100% and {>=}70% of the prescribed dose and maximum dose to 2 mL of the rectum and bladder. This was given by RV{sub 100}, RV{sub 70}, BV{sub 100}, BV{sub 70}, RD{sub max}, and BD{sub max}, respectively. When more than 1 of the first 3 fractions exceed the planning constraint as defined, it accurately predicts consistent failures through the course of the treatment. This method is able to correctly identify the consistent failures about 80% (RV{sub 70}, BV{sub 100}, and RV{sub 100}), 90% (BV{sub 70}), and 100% (RD{sub max} and BD{sub max}) of the times. Conclusions: This study demonstrates the feasibility of a method accurately identifying patients who are likely to consistently exceed the planning constraints during the course of their

  15. 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.

  16. Concomitant treatment of brain metastasis with Whole Brain Radiotherapy [WBRT] and Temozolomide [TMZ] is active and improves Quality of Life

    PubMed Central

    Addeo, Raffaele; Caraglia, Michele; Faiola, Vincenzo; Capasso, Elena; Vincenzi, Bruno; Montella, Liliana; Guarrasi, Rosario; Caserta, Luigi; Del Prete, Salvatore

    2007-01-01

    Background Brain metastases (BM) represent one of the most frequent complications related to cancer, and their treatment continues to evolve. We have evaluated the activity, toxicity and the impact on Quality of Life (QoL) of a concomitant treatment with whole brain radiotherapy (WBRT) and Temozolomide (TMZ) in patients with brain metastases from solid tumors in a prospective Simon two stage study. Methods Fifty-nine patients were enrolled and received 30 Gy WBRT with concomitant TMZ (75 mg/m2/day) for ten days, and subsequently TMZ (150 mg/m2/day) for up to six cycles. The primary end points were clinical symptoms and radiologic response. Results Five patients had a complete response, 21 patients had a partial response, while 18 patients had stable disease. The overall response rate (45%) exceeded the target activity per study design. The median time to progression was 9 months. Median overall survival was 13 months. The most frequent toxicities included grade 3 neutropenia (15%) and anemia (13%), and only one patient developed a grade 4 thrombocytopenia. Age, Karnofsky performance status, presence of extracranial metastases and the recursive partitioning analysis (RPA) were found to be predictive factors for response in patients. Overall survival (OS) and progression-free survival (PFS) were dependent on age and on the RPA class. Conclusion We conclude that this treatment is well tolerated, with an encouraging objective response rate, and a significant improvement in quality of life (p < 0.0001) demonstrated by FACT-G analysis. All patients answered the questionnaires and described themselves as 'independent' and able to act on their own initiatives. Our study found a high level of satisfaction for QoL, this provides useful information to share with patients in discussions regarding chemotherapy treatment of these lesions. PMID:17254350

  17. 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

  18. Long-term toxicity of chemotherapy and radiotherapy in lymphoma survivors: optimizing treatment for individual patients.

    PubMed

    Hodgson, David C

    2015-02-01

    Lymphoma treatment has evolved to reflect the fact that even when cure is achieved, significant chronic or late-onset toxicity can vitiate long-term patient outcomes. Previously, the sole focus of treatment was on maximizing cure rates. Now, the emphasis is on titrating treatment intensity to retain or improve cure rates while limiting treatment-associated late effects. To accomplish this on an individual basis remains clinically challenging. Most of the agents used in the treatment of Hodgkin and non-Hodgkin lymphoma have the potential to produce late--manifesting toxicities such as cardiac dysfunction, second malignancy, and infertility. This review outlines some of the evidence regarding late effects of chemotherapy and radiation for lymphoma, with emphasis on how understanding individual patient characteristics can affect the potential late toxicity of different treatment options.

  19. Effects of different postharvest treatments on the physiology and quality of 'Xiaobai' apricots at room temperature.

    PubMed

    Wu, Bin; Guo, Qin; Wang, Gang-Xia; Peng, Xin-Yuan; Wang, Ji-de; Che, Feng-Bin

    2015-04-01

    The effect of postharvest treatments on storage characteristics of harvested apricots in relation to fruit quality was investigated. 'Xiaobai' apricots treated with 1-methylcyclopropene (1-MCP), chlorine dioxide (ClO2), calcium, and heat in sealed container and then stored at 20 °C with 90 % relative humidity (RH) for 10 days. Results showed that the treatments could reduce respiration production and MDA content, delay softening, postharvest decay, the decrease of soluble solids (SSC), and visual changes. Furthermore, the polyphenol oxidase (PPO), polygalacturonase (PG), and pectin methylesterase (PME), superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) activities were reduced by treatments. Taken together, it is suggested that ClO2 treatment might be an effective way to maintain the quality of apricot fruit except 1-MCP treatment. PMID:25829606

  20. 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

  1. Psychological distress and quality of life in cervical cancer survivors after radiotherapy: do treatment modalities, disease stage, and self-esteem influence outcomes?

    PubMed

    Kobayashi, Mika; Ohno, Tatsuya; Noguchi, Wataru; Matsuda, Ayako; Matsushima, Eisuke; Kato, Shingo; Tsujii, Hirohiko

    2009-10-01

    The present study evaluated whether differences in the type of radiotherapy, disease stage, and self-esteem influence psychological distress and quality of life (QOL) among cervical cancer survivors. Sixty survivors, after radiotherapy, chemoradiotherapy, or postoperative radiotherapy for cervical cancer, participated in the study. The participants were asked to complete questionnaires during follow-up visits. The questionnaires included the Japanese version of the Hospital Anxiety and Depression Scale, the Functional Assessment of Cancer Therapy-General, and the Rosenberg Self-esteem Scale. The results indicated that psychological distress and QOL in cervical cancer survivors were not significantly different among treatment modalities and disease stage. Psychological distress and QOL differed significantly in accordance with the survivor's self-esteem. Survivors in the high self-esteem group had lower levels of anxiety and depression and higher QOL scores (emotional and social/family aspects of QOL and total QOL) than those in the low self-esteem group. Psychosocial support with consideration of a patient's self-esteem is necessary throughout and beyond radiotherapy for cervical cancer.

  2. 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.

  3. [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

  4. The UK Standardisation of Breast Radiotherapy (START) Trial B of radiotherapy hypofractionation for treatment of early breast cancer: a randomised trial

    PubMed Central

    2008-01-01

    Summary Background The international standard radiotherapy schedule for early breast cancer delivers 50 Gy in 25 fractions of 2·0 Gy over 5 weeks, but there is a long history of non-standard regimens delivering a lower total dose using fewer, larger fractions (hypofractionation). We aimed to test the benefits of radiotherapy schedules using fraction sizes larger than 2·0 Gy in terms of local-regional tumour control, normal tissue responses, quality of life, and economic consequences in women prescribed post-operative radiotherapy. Methods Between 1999 and 2001, 2215 women with early breast cancer (pT1-3a pN0-1 M0) at 23 centres in the UK were randomly assigned after primary surgery to receive 50 Gy in 25 fractions of 2·0 Gy over 5 weeks or 40 Gy in 15 fractions of 2·67 Gy over 3 weeks. Women were eligible for the trial if they were aged over 18 years, did not have an immediate reconstruction, and were available for follow-up. Randomisation method was computer generated and was not blinded. The protocol-specified principal endpoints were local-regional tumour relapse, defined as reappearance of cancer at irradiated sites, late normal tissue effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN59368779. Findings 1105 women were assigned to the 50 Gy group and 1110 to the 40 Gy group. After a median follow up of 6·0 years (IQR 5·0–6·2) the rate of local-regional tumour relapse at 5 years was 2·2% (95% CI 1·3–3·1) in the 40 Gy group and 3·3% (95% CI 2·2 to 4·5) in the 50 Gy group, representing an absolute difference of −0·7% (95% CI −1·7% to 0·9%)—ie, the absolute difference in local-regional relapse could be up to 1·7% better and at most 1% worse after 40 Gy than after 50 Gy. Photographic and patient self-assessments indicated lower rates of late adverse effects after 40 Gy than after 50 Gy. Interpretation A radiation schedule

  5. 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

  6. Clinical introduction of Monte Carlo treatment planning for lung stereotactic body radiotherapy.

    PubMed

    Miura, Hideharu; Masai, Norihisa; Oh, Ryoong-Jin; Shiomi, Hiroya; Yamada, Kouichi; Sasaki, Junichi; Inoue, Toshihiko

    2014-01-06

    The purpose of this study was to investigate the impact of Monte Carlo (MC) calculations and optimized dose definitions in stereotactic body radiotherapy (SBRT) for lung cancer patients. We used a retrospective patient review and basic virtual phantom to determine dose prescriptions. Fifty-three patients underwent SBRT. A basic virtual phantom had a gross tumor volume (GTV) of 10.0 mm with equivalent water density of 1.0 g/cm3, which was surrounded by equivalent lung surrounding the GTV of 0.25 g/cm3. D95 of the planning target volume (PTV) and D99 of the GTV were evaluated with different GTV sizes (5.0 to 30.0 mm) and different lung densities (0.05 to 0.45 g/cm3). Prescribed dose was defined as 95% of the PTV should receive 100% of the dose (48 Gy/4 fractions) using pencil beam (PB) calculation and recalculated using MC calculation. In the patient study, average doses to the D95 of the PTV and D99 of the GTV using the MC calculation plan were 19.9% and 10.2% lower than those by the PB calculation plan, respectively. In the phantom study, decreased doses to the D95 of the PTV and D99 of the GTV using the MC calculation plan were accompanied with changes GTV size from 30.0to 5.0 mm, which was decreased from 8.4% to 19.6% for the PTV and from 17.4%to 27.5% for the GTV. Similar results were seen with changes in lung density from 0.45 to 0.05 g/cm3, with doses to the D95 of the PTV and D99 of the GTV were decreased from 12.8% to 59.0% and from 7.6% to 44.8%, respectively. The decrease in dose to the PTV with MC calculation was strongly dependent on lung density. We suggest that dose definition to the GTV for lung cancer SBRT be optimized using MC calculation. Our current clinical protocol for lung SBRT is based on a prescribed dose of 44 Gy in 4 fractions to the GTV using MC calculation.

  7. Herbal preparation extract for skin after radiotherapy treatment. Part One--Preclinical tests.

    PubMed

    Skalska-Kamińska, Agnieszka; Woźniak, Anna; Paduch, Roman; Kocjan, Ryszard; Rejdak, Robert

    2014-01-01

    Naran R is a herbal composition made of Plantago lanceolate folium, Malvae arboreae flos, Calendulae flos, Chamomillae inflorescentia, Lamii albi flos to prepare compresses or to wash skin with inflammations. The extract of this preparation is mixed to be applied as an ointment on patients' skin after radiotherapy. Experiments performed in vitro are part of pre-clinical tests with Naran R ointment. This study examined the impact of the plant composition for ethanol-water extract on human skin fibroblasts (HSF) culture. Samples of extract, prepared from patented amounts of herbs, were in the range of 25-225 μg/mL. Six methods were applied: standard spectrophotometric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, neutral red (NR) uptake assay, DPPH free radical scavenging test, labeling of cytoskeleton F-actin, staining of argyrophilic nucleolar organizer regions (AgNORs) and trypan blue coloration. The extract concentration 75 μg/mL was established as safe for application on human skin. In labeling of F-actin with rhodamine-phalloidin dye at this concentration the cytoskeleton was stable. The extract did not influence the membrane stability and had positive influence on the proliferation activity. It was confirmed in AgNOR test during incubation with extract, which led to formation of larger amount of smaller nucleolins. In DPPH scavenging activity test, the extract revealed over 8% higher free-radical scavenging activity in comparison to control. After trypan blue staining, the extract in concentration 125 μg/mL significantly lowered the cell viability. When the cytotoxic and anti-proliferative activity of the extracts were analyzed, MTT and Neutral Red (NR) methods were used. The cells' viability was maintained on a constant level (80-110%) after 24, 48 and 72 h of incubation. During all time of NR test (72 h) and even when 225 μg/mL of extract was applied, the viability of cells was in range 80-110% of control. Positive influence

  8. Herbal preparation extract for skin after radiotherapy treatment. Part One--Preclinical tests.

    PubMed

    Skalska-Kamińska, Agnieszka; Woźniak, Anna; Paduch, Roman; Kocjan, Ryszard; Rejdak, Robert

    2014-01-01

    Naran R is a herbal composition made of Plantago lanceolate folium, Malvae arboreae flos, Calendulae flos, Chamomillae inflorescentia, Lamii albi flos to prepare compresses or to wash skin with inflammations. The extract of this preparation is mixed to be applied as an ointment on patients' skin after radiotherapy. Experiments performed in vitro are part of pre-clinical tests with Naran R ointment. This study examined the impact of the plant composition for ethanol-water extract on human skin fibroblasts (HSF) culture. Samples of extract, prepared from patented amounts of herbs, were in the range of 25-225 μg/mL. Six methods were applied: standard spectrophotometric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, neutral red (NR) uptake assay, DPPH free radical scavenging test, labeling of cytoskeleton F-actin, staining of argyrophilic nucleolar organizer regions (AgNORs) and trypan blue coloration. The extract concentration 75 μg/mL was established as safe for application on human skin. In labeling of F-actin with rhodamine-phalloidin dye at this concentration the cytoskeleton was stable. The extract did not influence the membrane stability and had positive influence on the proliferation activity. It was confirmed in AgNOR test during incubation with extract, which led to formation of larger amount of smaller nucleolins. In DPPH scavenging activity test, the extract revealed over 8% higher free-radical scavenging activity in comparison to control. After trypan blue staining, the extract in concentration 125 μg/mL significantly lowered the cell viability. When the cytotoxic and anti-proliferative activity of the extracts were analyzed, MTT and Neutral Red (NR) methods were used. The cells' viability was maintained on a constant level (80-110%) after 24, 48 and 72 h of incubation. During all time of NR test (72 h) and even when 225 μg/mL of extract was applied, the viability of cells was in range 80-110% of control. Positive influence

  9. 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.

  10. A Case of Metastatic Head and Neck Squamous Cell Carcinoma with Multiple Treatments Including Stereotactic Ablative Body Radiotherapy Alone for Oligometastases to the Parotid Gland

    PubMed Central

    Pederson, Aaron

    2015-01-01

    Head and neck squamous cell carcinoma (HNSCC) has a reported average of around 15% metastases at presentation with chemotherapy being the mainstay of treatment for widely metastatic disease. However, in select patients with oligometastatic disease, local ablative therapy (commonly including surgery or radiotherapy) can be utilized with the possibility of improving survival, decreasing morbidity from the metastases, and obviating the need for systemic therapy with its possible side effects. However, most research has been of ablative therapy has been performed for pulmonary and hepatic oligometastatic lesions.  In this case, we present a patient who initially presented with a metastatic base of tongue malignancy with left axilla metastases who was treated palliatively with systemic therapy with an initial complete response. She subsequently progressed on maintenance therapy with a locoregional recurrence that was treated with definitive chemoradiation with complete response. There was a subsequent recurrence again in the left axilla that was treated as well with chemoradiation with complete response. Next, there was a recurrence in the right occipital lobe and left parotid gland with treatment with surgical resection, plus stereotactic radiotherapy boost and stereotactic ablative body radiotherapy (SABR), respectively. This all occurred over a 30-month time frame from initial therapy to her last treatment, with an additional 42 months at the present time with no recurrence.  This case highlights the future of care of oligometastatic disease of HNSCC with potential long-term survival in appropriately selected patients treated with stereotactic ablative body radiotherapy. Furthermore, this is one of the first reported cases in the literature of SABR for an oligometastatic lesion of the parotid gland, especially from squamous cell carcinoma (SCC) of the oral cavity, with no recurrence of disease over 40 months removed from treatment. PMID:26858919

  11. 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.

  12. Implementation of in vivo Dosimetry with Isorad{sup TM} Semiconductor Diodes in Radiotherapy Treatments of the Pelvis

    SciTech Connect

    Rodriguez, Miguel L. Abrego, Eladio; Pineda, Amalia

    2008-04-01

    This report describes the results obtained with the Isorad{sup TM} (Red) semiconductor detectors for implementing an in vivo dosimetry program in patients subject to radiotherapy treatment of the pelvis. Four n-type semiconductor diodes were studied to characterize them for the application. The diode calibration consisted of establishing reading-to-dose conversion factors in reference conditions and a set of correction factors accounting for deviations of the diode response in comparison to that of an ion chamber. Treatments of the pelvis were performed by using an isocentric 'box' technique employing a beam of 18 MV with the shape of the fields defined by a multileaf collimator. The method of Rizzotti-Leunen was used to assess the dose at the isocenter based on measurements of the in vivo dose at the entrance and at the exit of each radiation field. The in vivo dose was evaluated for a population of 80 patients. The diodes exhibit good characteristics for their use in in vivo dosimetry; however, the high attenuation of the beam ({approx}12% at 5.0-cm depth) produced, and some important correction factors, must be taken into account. The correction factors determined, including the source-to-surface factor, were within a range of {+-}4%. The frequency histograms of the relative difference between the expected and measured doses at the entrance, the exit, and the isocenter, have mean values and standard deviations of -0.09% (2.18%), 0.77% (2.73%), and -0.11% (1.76%), respectively. The method implemented has proven to be very useful in the assessment of the in vivo dose in this kind of treatment.

  13. 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.

  14. 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.

  15. 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.

  16. [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

  17. 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.

  18. 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.

  19. Effect of radiotherapy delay in overall treatment time on local control and survival in head and neck cancer: Review of the literature

    PubMed Central

    González Ferreira, José A.; Jaén Olasolo, Javier; Azinovic, Ignacio; Jeremic, Branislav

    2015-01-01

    Treatment delays in completing radiotherapy (RT) for many neoplasms are a major problem affecting treatment outcome, as increasingly shown in the literature. Overall treatment time (OTT) could be a critical predictor of local tumor control and/or survival. In an attempt to establish a protocol for managing delays during RT, especially for heavily overloaded units, we have extensively reviewed the available literature on head and neck cancer. We confirmed a large deleterious effect of prolonged OTT on both local control and survival of these patients. PMID:26549990

  20. 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

  1. Definitive Radiotherapy Following Induction Chemotherapy for Hypopharyngeal Cancer: Selecting Candidates for Organ-Preserving Treatment Based on the Response to Induction Chemotherapy.

    PubMed

    Yanagi, Takeshi; Shibamoto, Yuta; Ogino, Hiroyuki; Baba, Fumiya; Murai, Taro; Nagai, Aiko; Miyakawa, Akifumi; Sugie, Chikao

    2016-01-01

    The outcomes of induction chemotherapy followed by radiotherapy for hypopharyngeal carcinoma were analyzed to determine whether response to induction chemotherapy could be a useful parameter for selecting candidates for organ-preserving therapy.Forty-three patients with hypopharyngeal carcinoma were treated with definitive radiotherapy with or without concurrent chemotherapy following induction chemotherapy. The predominant induction chemotherapy regimens involved cisplatin and 5-fluorouracil with or without docetaxel. The patients that responded to the induction chemotherapy received definitive organ-preserving treatment. Patients who did not respond to induction chemotherapy were considered for surgery, but only those patients who underwent definitive radiotherapy were analyzed in this study. Conventional radiotherapy was administered in all patients. The associations between clinical parameters including age, sex, performance status (PS), tumor site, T-category, N-category, stage, the regimen of induction chemotherapy, the response to induction chemotherapy, the presence/absence of concurrent chemotherapy, overall survival (OS), and local control (LC) were analyzed.Among the surviving patients, the follow-up period ranged from 10-145 months (median: 46 months). The 3-year OS and LC rates for all 43 patients were 61% and 70%, respectively. The 3-year OS and LC rates of the responders were 73% and 81%, respectively, whereas those of the non-responders were 29% and 40%, respectively. In multivariate analysis, only PS was correlated with overall survival (p=0.03). The complication rates were acceptable in all groups.Responders to induction chemotherapy appear to be good candidates for definitive organ-preserving treatment. Chemoselection appears to aid treatment selection in patients with hypopharyngeal carcinoma.

  2. Role of Radiotherapy in the Treatment of Cervical Lymph Node Metastases From an Unknown Primary Site: Retrospective Analysis of 113 Patients

    SciTech Connect

    Beldi, Debora; Jereczek-Fossa, Barbara A.; D'Onofrio, Alberto; Gambaro, Giuseppina; Fiore, Maria Rosaria; Pia, Francesco; Chiesa, Fausto; Orecchia, Roberto; Krengli, Marco

    2007-11-15

    Purpose: The management of patients with cervical lymph-node metastases from unknown primary site (UPS) remains a matter of discussion. This study aimed to analyze the results and prognostic factors in a series of patients treated with radiotherapy. Methods and Materials: Data from 113 patients who presented with cervical lymph nodes metastases from UPS treated from 1980 to 2004 were reviewed. Eighty-seven patients (77.0%) were squamous cell carcinoma (SCC). Ninety-one patients were treated with curative and 22 with palliative intent. Fifty-nine of 113 patients (52.2%) received surgery followed by radiotherapy and 54 of 113 (47.8%) received radiotherapy alone. Radiotherapy was delivered to the neck and pharyngeal mucosa in 67 patients and to the ipsilateral or bilateral neck in 45 patients. Twenty-one patients (18.5%) also received chemotherapy. Results: The 5-year overall survival rates were 40.7% for the entire group and 46.6% for the SCC subgroup. The occurrence of the occult primary was observed in 23 of 113 patients (20.3%), 19 (82.6%) within the head and neck region. At multivariate analysis, treatment with curative intent and extensive irradiation of bilateral neck and pharyngeal mucosa were favorable prognostic factors for the whole series, and treatment with curative intent, extensive irradiation of bilateral neck and pharyngeal mucosa, and absence of extracapsular spread were favorable prognostic factors for the SCC subgroup. Conclusions: Patients with cervical lymph node metastases from UPS have a similar prognosis to those affected by other head and neck malignancies. Curative treatment strategies including neck dissection and extensive irradiation by three-dimensional conformal radiation therapy resulted in significantly better outcomes.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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

  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. Efficacy and treatment-related toxicity of radiotherapy for early-stage primary non-Hodgkin lymphoma of the parotid gland

    SciTech Connect

    Olivier, Kenneth R. . E-mail: kolivier@ufl.edu; Brown, Paul D.; Stafford, Scott L.; Ansell, Stephen M.; Martenson, James A.

    2004-12-01

    Purpose: To assess the efficacy of radiotherapy (RT) in the treatment of primary non-Hodgkin lymphoma (NHL) of the parotid gland. Methods and materials: Data on 35 consecutive patients seen at Mayo Clinic between 1974 and 2000 with Ann Arbor Stage I and II NHL of the parotid gland were reviewed retrospectively. Radiotherapy was given to 23 patients, and 12 patients were observed. Eight patients received RT to local fields only. In addition to local fields, 9 patients received ipsilateral neck irradiation, and 6 patients received both ipsilateral and contralateral neck irradiation. Results: Median follow-up was 6.5 years (range, 2 months-24 years). Local control was significantly improved in the RT group compared with the observation group (p = 0.03). Both overall survival and disease-specific survival were 90% at 5 years and 71% at 10 years. There was no significant difference in disease-specific survival or overall survival between the RT and observation groups. Conclusions: The overall prognosis for this rare presentation of NHL is excellent. Radiotherapy provided significant improvement in local control with minimal morbidity and should be considered in the treatment of these patients.

  16. 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

  17. 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.

  18. 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

  19. Alternatives to chemotherapy and radiotherapy as adjuvant treatment for lung cancer.

    PubMed

    Shepherd, F A

    1997-06-01

    Because adjuvant chemotherapy has resulted in only modest prolongation of survival for patients with lung cancer, investigators have turned to the evaluation of alternative treatment strategies for this patient population. Immunotherapy with Bacillus Calmette Guerin, Corynebacterium parvum, and levamisole has been evaluated in several prospective randomized trials, and no study has shown a statistically significant difference in overall survival. Interferon has been evaluated in three trials of adjuvant therapy after response to chemotherapy for small cell lung cancer. Different interferon preparations were used, but none of the trials showed a significant prolongation of survival. The retinoids have been evaluated as adjuvant treatment after complete resection of stage IN-SCLC. One trial showed a reduction in second primary tumors, and in particular, tumors to tobacco smoking in patients treated with retinyl palmitate. A second trial using 13-cis retinoic acid is ongoing in North America. In the last decade, several inhibitors of angiogenesis have been identified, and they are now beginning to be evaluated in the clinical setting. The National Cancer Institute of Canada Clinical Trials Group and the European Organization for Research and Treatment of Cancer have initiated a study of adjuvant marimastat, a metalloproteinase inhibitor, for patients who have responded to induction chemotherapy for small cell lung cancer. This is the first adjuvant antiangiogenesis factor trial to be initiated for any tumor type. Other investigational agents which are currently undergoing Phase I and Phase II testing include monoclonal antibodies which may inhibit tumour cell growth by binding to growth factors, or which may be conjugated to toxins or chemotherapeutic agents which result in tumour cell death. In the last decade, we have witnessed an explosion in our knowledge and understanding of the regulation of normal and neoplastic cell growth at the molecular level. It remains

  20. Radiotherapy for craniopharyngioma.

    PubMed

    Aggarwal, Ajay; Fersht, Naomi; Brada, Michael

    2013-03-01

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

  1. [Radiotherapy of lymphomas].

    PubMed

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

    2016-09-01

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

  2. A comparison of proton therapy and IMRT treatment plans for prostate radiotherapy.

    PubMed

    Dowdell, S J; Metcalfe, P E; Morales, J E; Jackson, M; Rosenfeld, A B

    2008-12-01

    Proton therapy (PT) is becoming a more widely available treatment option on the world stage and there is some interest in investment in this treatment option in Australia. The benefit of PT has been shown for a number of tumour sites, particularly for paediatric patients. The workload from these patients may not completely fill the maximum yearly workload of a machine. This work aims to ascertain if prostate cancer would be a suitable candidate to fill the rest of the workload at an Australian PT facility. Passive and intensity modulated proton therapy (IMPT) plans were generated for a prostate patient. These were compared to 7 field sliding window and step and shoot IMRT plans. All plans used a prescription dose of 78 CGE. IMRT and IMPT plans used inverse planning for optimisation. Homogeneity in the PTV was best for the IMPT plan. IMPT also gave the best rectal sparing. The bladder and femoral heads were exposed to less dose in both proton plans. Proton plans exposed normal tissue outside the PTV to less than 50% of the dose given by the IMRT plans. PT, particularly IMPT, is a suitable treatment option for the prostate cancer patient presented here. PMID:19239059

  3. 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.

  4. Development of targeted radiotherapy systems

    NASA Astrophysics Data System (ADS)

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

    2001-10-01

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

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. Definitive Radiotherapy for Ewing Tumors of Extremities and Pelvis: Long-Term Disease Control, Limb Function, and Treatment Toxicity

    SciTech Connect

    Indelicato, Daniel J. Keole, Sameer R.; Shahlaee, Amir H.; Marcus, Robert B.

    2008-11-01

    Purpose: More than 70% of Ewing tumors occur in the extremities and pelvis. This study identified factors influencing local control and functional outcomes after management with definitive radiotherapy (RT). Patients and Methods: A total of 75 patients with a localized Ewing tumor of the extremity or pelvis were treated with definitive RT at the University of Florida between 1970 and 2006 (lower extremity tumors in 30, pelvic tumors in 26, and upper extremity tumors in 19). RT was performed on a once-daily (40%) or twice-daily (60%) basis. The median dose was 55.2 Gy in 1.8-Gy daily fractions or 55.0 Gy in 1.2-Gy twice-daily fractions. The median observed follow-up was 4.7 years. Functional outcome was assessed using the Toronto Extremity Salvage Score. Results: The 10-year actuarial overall survival, cause-specific survival, freedom from relapse, and local control rate was 48%, 48%, 42%, and 71%, respectively. Of the 72 patients, 3 required salvage amputation. Inferior cause-specific survival was associated with larger tumors (81% for tumors <8 cm vs. 39% for tumors {>=}8 cm, p <0.05). No patient characteristics or treatment variables were predictive of local failure. No fractures occurred in patients treated with hyperfractionation or with tumors of the distal extremities. Severe late complications were more frequently associated with use of <8-MV photons and fields encompassing the entire bone or hemipelvis. A significantly better Toronto Extremity Salvage Score was associated with a late-effect biologically effective dose of <91.7 Gy{sub 3}. Conclusions: Limb preservation was effectively achieved through definitive RT. Treating limited field sizes with hyperfractionated high-energy RT could minimize long-term complications and provides superior functional outcomes.

  14. 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.

  15. 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.

  16. 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

  17. 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

  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. 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

  20. NOTE: Gating characteristics of an Elekta radiotherapy treatment unit measured with three types of detector

    NASA Astrophysics Data System (ADS)

    Evans, Philip M.; Symonds-Tayler, J. Richard N.; Colgan, Ruth; Hugo, Geoffrey D.; Letts, Nicky; Sandin, Carlos

    2010-04-01

    The characteristics of an Elekta Precise treatment machine with a gating interface were investigated. Three detectors were used: a Farmer ionization chamber, a MatriXX ionization chamber array and an in-house, single pulse-measurement ionization chamber (IVC). Measurements were made of dosimetric accuracy, flatness and symmetry characteristics and duty cycle for a range of beam-on times and gating periods. Results were compared with a standard ungated delivery as a reference. For all beam-on times, down to 0.5 s, dosimetric differences were below ±1% and flatness and symmetry parameter variations were below ±1.5%. For the shorter beam-on times the in-house detector deviated from the other two detectors, suggesting that this device should be used in conjunction with other detectors for absolute dosimetry purposes. However, it was found to be useful for studying gated beam characteristics pulse by pulse.

  1. Practical aspects and applications of the biological effective dose three-dimensional calculation for multi-phase radiotherapy treatment plans

    NASA Astrophysics Data System (ADS)

    Kauweloa, Kevin Ikaika

    The approximate BED (BEDA) is calculated for multi-phase cases due to current treatment planning systems (TPSs) being incapable of performing BED calculations. There has been no study on the mathematical accuracy and precision of BEDA relative to the true BED (BEDT), and how that might negatively impact patient care. The purpose of the first aim was to study the mathematical accuracy and precision in both hypothetical and clinical situations, while the next two aims were to create multi-phase BED optimization ideas for both multi-target liver stereotactic body radiation therapy (SBRT) cases, and gynecological cases where patients are treated with high-dose rate (HDR) brachytherapy along with external beam radiotherapy (EBRT). MATLAB algorithms created for this work were used to mathematically analyze the accuracy and precision of BEDA relative to BEDT in both hypothetical and clinical situations on a 3D basis. The organs-at-risk (OARs) of ten head & neck and ten prostate cancer patients were studied for the clinical situations. The accuracy of BEDA was shown to vary between OARs as well as between patients. The percentage of patients with an overall BEDA percent error less than 1% were, 50% for the Optic Chiasm and Brainstem, 70% for the Left and Right Optic Nerves, as well as the Rectum and Bladder, and 80% for the Normal Brain and Spinal Cord. As seen for each OAR among different patients, there were always cases where the percent error was greater than 1%. This is a cause for concern since the goal of radiation therapy is to reduce the overall uncertainty of treatment, and calculating BEDA distributions increases the treatment uncertainty with percent errors greater than 1%. The revealed inaccuracy and imprecision of BEDA supports the argument to use BEDT. The multi-target liver study involved applying BEDT in order to reduce the number of dose limits to one rather than have one for each fractionation scheme in multi-target liver SBRT treatments. A BEDT limit

  2. In-room CT techniques for image-guided radiation therapy

    SciTech Connect

    Ma, C.-M. Charlie . E-mail: charlie.ma@fccc.edu; Paskalev, Kamen M.S.

    2006-04-01

    Accurate patient setup and target localization are essential to advanced radiation therapy treatment. Significant improvement has been made recently with the development of image-guided radiation therapy, in which image guidance facilitates short treatment course and high dose per fraction radiotherapy, aiming at improving tumor control and quality of life. Many imaging modalities are being investigated, including x-ray computed tomography (CT), ultrasound imaging, positron emission tomography, magnetic resonant imaging, magnetic resonant spectroscopic imaging, and kV/MV imaging with flat panel detectors. These developments provide unique imaging techniques and methods for patient setup and target localization. Some of them are different; some are complementary. This paper reviews the currently available kV x-ray CT systems used in the radiation treatment room, with a focus on the CT-on-rails systems, which are diagnostic CT scanners moving on rails installed in the treatment room. We will describe the system hardware including configurations, specifications, operation principles, and functionality. We will review software development for image fusion, structure recognition, deformation correction, target localization, and alignment. Issues related to the clinical implementation of in-room CT techniques in routine procedures are discussed, including acceptance testing and quality assurance. Clinical applications of the in-room CT systems for patient setup, target localization, and adaptive therapy are also reviewed for advanced radiotherapy treatments.

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

    PubMed

    Wu, S X; Wang, L H

    2016-09-23

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

  4. Randomized, prospective assessment of moisturizer efficacy for the treatment of radiation dermatitis following radiotherapy after breast-conserving surgery

    PubMed Central

    Sekiguchi, Kenji; Ogita, Mami; Akahane, Keiko; Haga, Chiori; Ito, Ryoko; Arai, Satoru; Ishida, Yasushi; Tsukada, Yoichiro; Kawamori, Jiro

    2015-01-01

    Objective The effect of heparinoid moisturizer use after acute skin damage for patients receiving whole-breast radiotherapy after lumpectomy is understudied. Methods A total of 30 patients were randomly assigned to receive heparinoid moisturizer (Group M), and 32 patients comprised the control group (Group C). Patients in Group M were instructed to apply heparinoid moisturizer from 2 weeks following whole-breast radiotherapy, and to continue to use the moisturizer until 3 months after completion of whole-breast radiotherapy. Group C patients were instructed to not apply any topical moisturizer during the study period. The relative ratio of skin water content ratio (RWCR(t) = (It /Nt)/(I0/N0)) between irradiated and non-irradiated field was calculated. Signs and symptoms were also assessed. The primary endpoint was the difference in relative ratio of skin water content ratio between 2 and 4 weeks following whole-breast radiotherapy. Results In Group C, relative ratio of skin water content ratio dropped to 0.80 ± 0.15 at 2 weeks and maintained the low level at 4 weeks following whole-breast radiotherapy. Similarly, in Group M, relative ratio of skin water content ratio dropped to 0.81 ± 0.19 at 2 weeks (prior to application), however, it returned to baseline level (1.05 ± 0.23) at 4 weeks (2 weeks after application). The arithmetic difference of relative ratio of skin water content ratio in Group M was 0.24 ± 0.23 and was significantly larger than in Group C (0.06 ± 0.15; P < 0.01). Skin dryness and desquamation were less severe in Group M. Conclusions The application of heparinoid moisturizer for 2 weeks following whole-breast radiotherapy significantly increased water content and helped improve skin dryness and desquamation compared with no use of moisturizer. PMID:26491204

  5. 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.

  6. [Innovation in adjuvant radiotherapy for breast cancer: new biologic parameters, a perspective for treatment tailoring].

    PubMed

    Belkacémi, Y

    2009-01-01

    In the adjuvant setting, whole breast radiation therapy (RT) delivering 50 Gy in 5 weeks with or without a boost to the tumor bed remains the standard of care. RT indications and volume definition are generally dependant on existing prognostic factors. Except in particular cases, RT technique does not vary according to the patient or tumor biology profiles in terms of total dose, dose per fraction, fractionation, and RT duration. The challenge is to define new parameters or tumor biology profiles that will allow patient selection for more tailored RT than the 5 to 7 week standard schedules. The future issue is to define biological markers able to screen patients and tumors according to their high metastatic potential (in which the primary therapeutic challenge may not be locoregional control) and those patients that have a particular radiosensitivity to ionizing radiation for higher benefit/risk ratio. Thus, it is probable that patient profiles, tumor biology markers and gene expression profiling could provide in future an added value to conventional markers to predict patients at high-risk of local and distant recurrences who need tailored treatment or a particular sequence of adjuvant therapy.

  7. Long-term results of radiotherapy in the treatment of pituitary adenomas in children and adolescents

    SciTech Connect

    Grigsby, P.W.; Thomas, P.R.; Simpson, J.R.; Fineberg, B.B.

    1988-12-01

    A retrospective review was performed of 11 children and adolescents (less than 19 years of age) with diagnosed pituitary adenomas. The patients were treated with subtotal resection and postoperative irradiation (S + R) or with irradiation alone (RT) at the Radiation Oncology Center, Mallinckrodt Institute of Radiology, Washington University Medical Center, from January 1958 through December 1982. Patient conditions at diagnosis were acromegaly in one, Nelson's syndrome in one, prolactinoma in three, chromophobe adenoma in three, and Cushing's disease in three. Median follow-up was 15.6 years (range 6.3-29.5 years). Only two patients have had failure: one at 8.6 years and the other at 20.7 years following treatment. All four patients with visual field (VF) defects at diagnosis underwent S + R, with only one developing recurrent disease. The remaining seven patients, who did not have VF defects, received RT only, and there has been one failure in this group. None have suffered long-term visual complications. All have been able to continue school and/or work. Three of eight females have borne children. Hypopituitarism requiring medication occurred in all who received S + R and in four of seven who received RT only.

  8. 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

  9. 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.

  10. 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.

  11. Practical guidelines for routine intensity-modulated radiotherapy verification: pre-treatment verification with portal dosimetry and treatment verification with in vivo dosimetry

    PubMed Central

    Vinall, A J; Williams, A J; Currie, V E; Van Esch, A; Huyskens, D

    2010-01-01

    The purpose of this work is to provide guidelines for the routine use of portal dosimetry and in vivo diode measurements to verify intensity-modulated radiotherapy (IMRT) treatments. To achieve tolerance levels that are sensitive enough to intercept problems, both the portal dosimetry and the in vivo procedure must be optimised. Portal dosimetry was improved by the introduction of an optimised two-dimensional (2D) profile correction, which also accounted for the effect of backscatter from the R-arm. The scaled score, indicating the fraction of points not meeting the desired gamma evaluation criteria within the field opening, was determined as the parameter of interest. Using gamma criteria of a 3% dose difference and 3 mm distance to agreement, a “scaled score” threshold value of 1.5% was chosen to indicate excessive tongue and groove and other problems. The pre-treatment portal dosimetry quality assurance (QA) does not encompass verification of the patient dose calculation or position, and so it is complemented by in vivo diode measurements. Diode positioning is crucial in IMRT, and so we describe a method for diode positioning at any suitable point. We achieved 95% of IMRT field measurements within ±5% and 99% within ±8%, with improved accuracy being achieved over time owing to better positioning. Although the careful preparation and setup of the diode measurements can be time-consuming, this is compensated for by the time efficiency of the optimised procedure. Both methods are now easily absorbed into the routine work of the department. PMID:20965905

  12. [Use of laser for the prevention and treatment of oral mucositis induced by radiotherapy and chemotherapy for head and neck cancer].

    PubMed

    Muñoz-Corcuera, Marta; González-Nieto, Almudena; López-Pintor Muñoz, Rosa María

    2014-08-19

    One of the complications of radiotherapy and chemotherapy is oral mucositis. Since the low energy laser is one of the most frequently recommended interventions by authors and international societies, the aim of this study is to review the scientific evidence on the use of lasers as a preventive and therapeutic in oral mucositis associated with treatment of cancer. We performed a literature search in PubMed and The Cochrane Collaboration Library, limiting the search to the last 20 years. We finally included 29 articles that contained 30 studies. Low energy laser phototherapy seems a promising intervention in both the prevention and treatment of oral mucositis associated with cancer treatment. Virtually all studies reviewed showed good results with no adverse effects and reductions in both incidence and severity of mucositis in all types of cancer treatments.

  13. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  14. 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

  15. Radiotherapy Accidents

    NASA Astrophysics Data System (ADS)

    Mckenzie, Alan

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

  16. 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

  17. Management of radiotherapy-induced skin reactions.

    PubMed

    Trueman, Ellen

    2015-04-01

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

  18. 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.

  19. [Radiotherapy of breast cancer].

    PubMed

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

    2016-09-01

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

  20. 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.

  1. 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.

  2. Developments in radiotherapy.

    PubMed

    Svensson, Hans; Möller, Torgil R

    2003-01-01

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

  3. [External radiotherapy for hepatocellular carcinoma].

    PubMed

    Girard, N; Mornex, F

    2011-02-01

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

  4. [Radiotherapy of cerebral metastases].

    PubMed

    Soffietti, R

    1984-05-31

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

  5. 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.

  6. Adjuvant and Definitive Radiotherapy for Adrenocortical Carcinoma

    SciTech Connect

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

    2011-08-01

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

  7. 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.

  8. 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.

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

    PubMed

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

    2013-10-01

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

  10. Treatment of advanced stage ovarian carcinoma with a combination of chemotherapy, radiotherapy, and radiosensitizer: report of a pilot study from the National Cancer Institute

    SciTech Connect

    Lichter, A.S.; Ozols, R.F.; Myers, C.C.; Ostechega, Y.; Young, R.C.

    1987-08-01

    Twenty-eight patients with Stage III or IV ovarian carcinoma were treated with combined chemotherapy-radiotherapy employing a unique protocol. Four cycles of cyclophosphamide and hexamethylmelamine alternated with four cycles of concurrent cisplatin, whole abdominal radiotherapy, and intraperitoneal misonidazole. The entire treatment program lasted six months. Clinical complete responses were seen in 50% of the patients with an overall response rate of 61%. Pathologic complete response (PCR) confirmed at second look surgery occurred in 18% of the group (5 patients). Median survival of the entire group was 15.2 months with all PCR's alive NED. This outcome was no different than our previous experience with combination chemotherapy alone. Toxicities seen included leukopenia, thrombocytopenia, nausea, vomiting, and weight loss. However, these side effects were manageable. Two non-tumor deaths occurred. This study demonstrates the feasibility of combining drug and radiation therapy concurrently in the treatment of ovarian cancer; further research is needed to explore different sequencing and dose levels that could improve the outcome.

  11. 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

  12. Dosimetric benefits of IMRT and VMAT in the treatment of middle thoracic esophageal cancer: is the conformal radiotherapy still an alternative option?

    PubMed

    Wu, Zhiqin; Xie, Congying; Hu, Meilong; Han, Ce; Yi, Jinling; Zhou, Yongqiang; Yuan, Huawei; Jin, Xiance

    2014-05-08

    The purpose of this study is to investigate the dosimetric differences among conformal radiotherapy (CRT), intensity-modulated radiotherapy (IMRT), and volumetric-modulated radiotherapy (VMAT) in the treatment of middle thoracic esophageal cancer, and determine the most appropriate treatment modality. IMRT and one-arc VMAT plans were generated for eight middle thoracic esophageal cancer patients treated previous with CRT. The planning target volume (PTV) coverage and protections on organs at risk of three planning schemes were compared. All plans have sufficient PTV coverage and no significant differences were observed, except for the conformity and homogeneity. The lung V5, V10, and V13 in CRT were 47.9% ± 6.1%, 36.5% ± 4.6%, and 33.2% ± 4.2%, respectively, which were greatly increased to 78.2% ± 13.7% (p < 0.01), 80.8% ± 14.9% (p < 0.01), 48.4% ± 8.2% (p = 0.05) in IMRT and 58.6% ± 10.5% (p = 0.03), 67.7% ± 14.0% (p < 0.01), and 53.0% ± 10.1% (p < 0.01) in VMAT, respectively. The lung V20 (p = 0.03) in VMAT and the V30 (p = 0.04) in IMRT were lower than those in CRT. Both IMRT and VMAT achieved a better protection on heart. However, the volumes of the healthy tissue outside of PTV irradiated by a low dose were higher for IMRT and VMAT. IMRT and VMAT also had a higher MU, optimization time, and delivery time compared to CRT. In conclusion, all CRT, IMRT, and VMAT plans are able to meet the prescription and there is no clear distinction on PTV coverage. IMRT and VMAT can only decrease the volume of lung and heart receiving a high dose, but at a cost of delivering low dose to more volume of lung and normal tissues. CRT is still a feasible option for middle thoracic esophageal cancer radiotherapy, especially for the cost-effective consideration.

  13. Comparison of Treatment Outcomes between Breast Conserving Surgery Followed by Radiotherapy and Mastectomy Alone in Patients with T1-2 Stage and 1-3 Axillary Lymph Nodes in the Era of Modern Adjuvant Systemic Treatments

    PubMed Central

    Kim, Sang-Won; Chun, Mison; Han, Sehwan; Jung, Yong Sik; Choi, Jin Hyuk; Kang, Seok Yun; Jang, Hyunsoo; Jo, Sunmi

    2016-01-01

    Purpose The role of postmastectomy radiotherapy in the treatment of T1–2 primary tumor with 1–3 positive lymph nodes is controversial. We compared treatment outcomes between breast conserving surgery followed by radiotherapy (BCS+RT) and total mastectomy alone (TM) in the setting of modern adjuvant systemic treatments. Methods Patients with T1–2 primary breast cancer and 1–3 positive lymph nodes who were treated between 2001 and 2011 were divided into 2 groups based on the treatment approach: BCS+RT (n = 169) and TM (n = 117). All patients received adjuvant chemotherapy including taxanes. Adjuvant endocrine therapy was administered to patients with positive hormone receptors according to their menstrual status. Results During a median follow-up of 76.5 months, 21 patients (7.3%) experienced locoregional recurrence as the first event, including 7 patients (4.1%) in the BCS+RT group and 14 patients (12.0%) in the TM group. The 5-year cumulative incidence rate of locoregional recurrence was 2.5% for BCS+RT versus 9.5% for TM (p = 0.016). Competing risk regression analysis revealed that TM was associated with a relative risk for locoregional recurrence of 5.347 (p = 0.003). TM was also associated with a significantly lower 5-year disease-free survival rate compared with BCS+RT (hazard ratio, 2.024; 95% confidence interval, 1.090–3.759; p = 0.026). Conclusion To improve treatment outcomes for TM even after modern systemic treatments, postmastectomy radiotherapy might be required for patients with T1–2 primary breast cancer and 1–3 positive lymph nodes. PMID:27685357

  14. Phase I Study of Oxaliplatin in Combination With Capecitabine and Radiotherapy as Postoperative Treatment for Stage II and III Rectal Cancer

    SciTech Connect

    Jin Jing

    2008-11-01

    Purpose: A Phase I study was conducted to determine the maximal tolerated dose and the dose-limiting toxicity (DLT) of oxaliplatin (OXA) combined with capecitabine and radiotherapy as adjuvant treatment in patients with operable rectal cancer. Patients and Methods: A total of 21 patients with Stage II or III rectal adenocarcinoma after curative surgery were treated with radiotherapy to a total dose of 50 Gy in 5 weeks. OXA was administered at a dosage of 40 (n = 6), 50 (n = 3),60 (n = 3), 70 (n = 3), or 80 mg/m{sup 2} (n = 6) once a week for 2 weeks (first cycle) followed by a second cycle after a 7-day break. Capecitabine at a fixed dose of 1,300 mg/m{sup 2}/d was administered orally at the same schedule as for OXA. DLT was defined as Grade 3 or 4 hematologic and nonhematologic toxicity. Results: Grade 1-3 leukopenia, diarrhea, and nausea/vomiting were the most common toxic side effects, and most were Grade 1-2. A DLT was first observed in 1 of 3 patients at 40 mg/m{sup 2} (Grade 3 diarrhea) but was not observed in the next 3 patients at the same level or in patients who received a dose level of 50-70 mg/m{sup 2}. At 80 mg/m{sup 2}, DLT occurred in 3 of 6 patients (1 Grade 4 leukopenia and 2 Grade 3 diarrhea). Conclusions: OXA combined with a fixed dose of capecitabine at 625 mg/m{sup 2} twice daily by mouth plus radiotherapy in the adjuvant setting was tolerable and clinically feasible. The maximal tolerated dose of OXA in this setting was 80 mg/m{sup 2}, comparable to the maximal tolerated dose of OXA in the neoadjuvant setting.

  15. Sci—Fri PM: Dosimetry—02: A Nested Neutron Spectrometer to Measure Neutron Spectra in Radiotherapy

    SciTech Connect

    Maglieri, R; Seuntjens, J; Kildea, J; Licea, A

    2014-08-15

    During high-energy radiotherapy treatments, neutrons are produced in the head of the linac through photonuclear interactions. This has been a concern for many years as photoneutrons contribute to the accepted, yet unwanted, out-of-field doses that pose an iatrogenic risk to patients and an occupational risk to personnel. Presently, in-room neutron measurements are difficult and time-consuming and have traditionally been carried out using Bonner spheres with activation foils and TLDs. In this work, a new detector, the Nested Neutron Spectrometer (NNS) is tested for use in radiotherapy bunkers. The NNS is designed for easy handling and is more practical than the traditional Bonner spheres. The NNS, operated in current mode, was used to measure the dose equivalent, average energy and energy spectrum at several positions in a radiotherapy bunker. The average energy and spectra were compared to Monte Carlo simulations while the dose equivalent was compared to bubble detector measurements. The average energies, as measured by the NNS and Monte Carlo simulations, differed by approximately 30% across the bunker. Measurements of the dose equivalent using the NNS and the bubble detectors agreed within 50% in the maze and less than 10% close to the linac head. Apart from some discrepancies at thermal energies, we also found reasonable agreement between NNS-measured and Monte Carlo-simulated spectra at a number of locations within our radiotherapy bunker. Our results demonstrate that the NNS is a suitable detector to be used in high dose-rate radiotherapy environments.

  16. Patterns of Radiotherapy Practice for Patients With Cervical Cancer (1999-2001): Patterns of Care Study in Japan

    SciTech Connect

    Toita, Takafumi Kodaira, Takeshi; Shinoda, Atsunori; Uno, Takashi; Akino, Yuichi; Mitsumori, Michihide; Teshima, Teruki

    2008-03-01

    Purpose: To describe the patterns of definitive radiotherapy practice for patients with uterine cervical cancer from 1999 to 2001 in Japan. Methods and Materials: The Japanese Patterns of Care Study (JPCS) working group conducted a third extramural audit survey of 68 institutions and collected specific information on 324 cervical cancer patients treated with definitive radiotherapy. Results: Almost all patients (96%) were treated with whole pelvic radiotherapy using opposing anteroposterior fields (87%). A midline block was used in 70% of the patients. Intracavitary brachytherapy (ICBT) was applied in 82% of cases. Most patients (89%) were treated with high-dose rate (HDR) ICBT. Calculation of doses to organs at risk (ICRU 38) was performed for rectum in 25% of cases and for bladder in 18% of cases. Only 3% of patients were given intravenous conscious sedation during ICBT applicator insertions. The median total biologically effective dose at point A (EBRT+ICBT) was 74 Gy{sub 10} in cases treated with HDR-ICBT. There was no significant difference in total biologically effective dose between stages. The median overall treatment time was 47 days. Concurrent chemoradiation was applied in 17% of patients. Conclusions: This study describes the general patterns of radiotherapy practice for uterine cervical cancer in Japan. Although methods of external radiotherapy seemed to be appropriate, there was room for improvement in ICBT practice, such as pretreatment. A substantial difference in total radiotherapy dose between Japan and the United States was observed.

  17. Primary Aorto-Duodenal Fistula as a Late Complication of Radiotherapy: Report of a Case and Review of the Literature

    PubMed Central

    Puccio, Francesco; Pandolfo, Gianpiero; Chiodini, Stefano; Benzi, Fabrizia; Solazzo, Massimiliano

    2008-01-01

    Primary aorto-duodenal fistula (PADF) is a rare condition that may result in rapid exsanguination if untreated. PADF due to radiotherapy appears to be extremely rare with only a few cases reported in the medical literature. We report the case of a 61-year-old man who presented with massive gastrointestinal bleeding 25 years after surgery and radiotherapy for seminoma of the testicle and was successfully treated at our institution. We also review the literature on this very uncommon condition. A Medline search was conducted for the period from 1966 to June 2006 to identify case reports of PADF following radiotherapy. Only 7 cases of PADF due to radiotherapy were identified in addition to our own, 4 males and 3 females, aged 40 to 73 years, all treated for various forms of abdominal malignancies. The latency period ranged from 2 weeks to 25 years. None of the aortas were aneurysmatic. One patient died before he could be taken to the operating room. 5 patients underwent surgical repair and 4 survived. 2 patients underwent endovascular treatment but did not survive. PADF may develop up to 25 years after radiotherapy. Diagnosis should be considered when massive upper gastrointestinal bleeding develops in a patient who had previous abdominal radiotherapy, no matter how long before the episode of bleeding. Prompt surgical repair offers a reasonable chance of cure. Endovascular procedures do not appear to be efficacious. PMID:21897792

  18. Thoracic target volume delineation using various maximum-intensity projection computed tomography image sets for radiotherapy treatment planning

    SciTech Connect

    Zamora, David A.; Riegel, Adam C.; Sun Xiaojun; Balter, Peter; Starkschall, George; Mawlawi, Osama; Pan Tinsu

    2010-11-15

    Purpose: Four-dimensional computed tomography (4D-CT) is commonly used to account for respiratory motion of target volumes in radiotherapy to the thorax. From the 4D-CT acquisition, a maximum-intensity projection (MIP) image set can be created and used to help define the tumor motion envelope or the internal gross tumor volume (iGTV). The purpose of this study was to quantify the differences in automatically contoured target volumes for usage in the delivery of stereotactic body radiation therapy using MIP data sets generated from one of the four methods: (1) 4D-CT phase-binned (PB) based on retrospective phase calculations, (2) 4D-CT phase-corrected phase-binned (PC-PB) based on motion extrema, (3) 4D-CT amplitude-binned (AB), and (4) cine CT built from all available images. Methods: MIP image data sets using each of the four methods were generated for a cohort of 28 patients who had prior thoracic 4D-CT scans that exhibited lung tumor motion of at least 1 cm. Each MIP image set was automatically contoured on commercial radiation treatment planning system. Margins were added to the iGTV to observe differences in the final simulated planning target volumes (PTVs). Results: For all patients, the iGTV measured on the MIP generated from the entire cine CT data set (iGTV{sub cine}) was the largest. Expressed as a percentage of iGTV{sub cine}, 4D-CT iGTV (all sorting methods) ranged from 83.8% to 99.1%, representing differences in the absolute volume ranging from 0.02 to 4.20 cm{sup 3}; the largest average and range of 4D-CT iGTV measurements was from the PC-PB data set. Expressed as a percentage of PTV{sub cine} (expansions applied to iGTV{sub cine}), the 4D-CT PTV ranged from 87.6% to 99.6%, representing differences in the absolute volume ranging from 0.08 to 7.42 cm{sup 3}. Regions of the measured respiratory waveform corresponding to a rapid change of phase or amplitude showed an increased susceptibility to the selection of identical images for adjacent bins

  19. Continuous table acquisition MRI for radiotherapy treatment planning: Distortion assessment with a new extended 3D volumetric phantom

    SciTech Connect

    Walker, Amy Metcalfe, Peter; Liney, Gary; Holloway, Lois; Dowling, Jason; Rivest-Henault, David

    2015-04-15

    Purpose: Accurate geometry is required for radiotherapy treatment planning (RTP). When considering the use of magnetic resonance imaging (MRI) for RTP, geometric distortions observed in the acquired images should be considered. While scanner technology and vendor supplied correction algorithms provide some correction, large distortions are still present in images, even when considering considerably smaller scan lengths than those typically acquired with CT in conventional RTP. This study investigates MRI acquisition with a moving table compared with static scans for potential geometric benefits for RTP. Methods: A full field of view (FOV) phantom (diameter 500 mm; length 513 mm) was developed for measuring geometric distortions in MR images over volumes pertinent to RTP. The phantom consisted of layers of refined plastic within which vitamin E capsules were inserted. The phantom was scanned on CT to provide the geometric gold standard and on MRI, with differences in capsule location determining the distortion. MRI images were acquired with two techniques. For the first method, standard static table acquisitions were considered. Both 2D and 3D acquisition techniques were investigated. With the second technique, images were acquired with a moving table. The same sequence was acquired with a static table and then with table speeds of 1.1 mm/s and 2 mm/s. All of the MR images acquired were registered to the CT dataset using a deformable B-spline registration with the resulting deformation fields providing the distortion information for each acquisition. Results: MR images acquired with the moving table enabled imaging of the whole phantom length while images acquired with a static table were only able to image 50%–70% of the phantom length of 513 mm. Maximum distortion values were reduced across a larger volume when imaging with a moving table. Increased table speed resulted in a larger contribution of distortion from gradient nonlinearities in the through

  20. Patterns of Failure and Treatment-Related Toxicity in Advanced Cervical Cancer Patients Treated Using Extended Field Radiotherapy With Curative Intent

    SciTech Connect

    Rajasooriyar, Chrishanthi; Van Dyk, Sylvia; Bernshaw, David; Kondalsamy-Chennakesavan, Srinivas; Barkati, Maroie; Narayan, Kailash

    2011-06-01

    Purpose: The purpose of this study was to evaluate the patterns of failure and overall survival (OS) and disease-free survival (DFS) rates in cervical cancer patients who had metastatic disease in common iliac or para-aortic lymph nodes and were treated with curative intent, using extended field radiotherapy (EFRT). Methods and Materials: This was a retrospective study involving 39 patients treated from January 1996 to June 2007, using EFRT with concurrent chemotherapy and intracavitary brachytherapy. EFRT consisted of 45 Gy in 1.8-Gy fractions. Radiation to involved nodes was boosted to a total dose of 50.4 to 54 Gy. Primary tumor radiation was boosted to a dose of 80 Gy using brachytherapy. Results: Overall, 30 patients (77%) have relapsed. The 5-year OS rate was 26% (95% confidence interval [CI], 11-44). The 5-year DFS rate was 19.4% (95% CI, 8-35). Only 3 patients (7.5%) experienced treatment failure exclusively within the treatment field, and 2 patients underwent salvage treatment. Grade 3 to 4 acute bone marrow and gastrointestinal toxicities were observed in 10 (26%) and 7 (18%) patients, respectively. Conclusions: Concurrent chemotherapy and EFRT treatment was well tolerated. Most patients showed failure at multiple sites and outside the treatment field. Only 3/39 patients had failures exclusively within the treatment field, and 2 underwent salvage treatment.

  1. Local image descriptor-based searching framework of usable similar cases in a radiation treatment planning database for stereotactic body radiotherapy

    NASA Astrophysics Data System (ADS)

    Nonaka, Ayumi; Arimura, Hidetaka; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Soufi, Mazen; Magome, Taiki; Honda, Hiroshi; Hirata, Hideki

    2014-03-01

    Radiation treatment planning (RTP) of the stereotactic body radiotherapy (SBRT) was more complex compared with conventional radiotherapy because of using a number of beam directions. We reported that similar planning cases could be helpful for determination of beam directions for treatment planners, who have less experiences of SBRT. The aim of this study was to develop a framework of searching for usable similar cases to an unplanned case in a RTP database based on a local image descriptor. This proposed framework consists of two steps searching and rearrangement. In the first step, the RTP database was searched for 10 cases most similar to object cases based on the shape similarity of two-dimensional lung region at the isocenter plane. In the second step, the 5 most similar cases were selected by using geometric features related to the location, size and shape of the planning target volume, lung and spinal cord. In the third step, the selected 5 cases were rearranged by use of the Euclidean distance of a local image descriptor, which is a similarity index based on the magnitudes and orientations of image gradients within a region of interest around an isocenter. It was assumed that the local image descriptor represents the information around lung tumors related to treatment planning. The cases, which were selected as cases most similar to test cases by the proposed method, were more resemble in terms of the tumor location than those selected by a conventional method. For evaluation of the proposed method, we applied a similar-cases-based beam arrangement method developed in the previous study to the similar cases selected by the proposed method based on a linear registration. The proposed method has the potential to suggest the superior beam-arrangements from the treatment point of view.

  2. A New Brain Positron Emission Tomography Scanner With Semiconductor Detectors for Target Volume Delineation and Radiotherapy Treatment Planning in Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Katoh, Norio; Yasuda, Koichi; Shiga, Tohru; Hasegawa, Masakazu; Onimaru, Rikiya; Shimizu, Shinichi; Bengua, Gerard; Ishikawa, Masayori; Tamaki, Nagara; Shirato, Hiroki

    2012-03-15

    Purpose: We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PET{sub CONV}WB) versus the new brain (BR) PET system using semiconductor detectors (PET{sub NEW}BR). Methods and Materials: Twelve patients with NPC were enrolled in this study. [{sup 18}F]Fluorodeoxyglucose-PET images were acquired using both the PET{sub NEW}BR and the PET{sub CONV}WB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PET{sub CONV}WB and PET{sub NEW}BR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PET{sub CONV}WB (GTV{sub CONV}) images or PET{sub NEW}BR (GTV{sub NEW}) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. Results: The average absolute volume ({+-}standard deviation [SD]) of GTV{sub NEW} was 15.7 ml ({+-}9.9) ml, and that of GTV{sub CONV} was 34.0 ({+-}20.5) ml. The average GTV{sub NEW} was significantly smaller than that of GTV{sub CONV} (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN{sub NEW}) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Conclusion: Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy

  3. A Simulation Study of a Radiofrequency Localization System for Tracking Patient Motion in Radiotherapy

    PubMed Central

    Ostyn, Mark; Kim, Siyong; Yeo, Woon-Hong

    2016-01-01

    One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF) localization system designed to track intrafraction motion (target motion during the radiation treatment). This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range) for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a localization estimate and angular resolution of sensors (signal receivers) in a simulated room. The results indicate that the external sensor needs an angular resolution of about 0.03 degrees to achieve millimeter-level localization accuracy in a treatment room. This fundamental study of a novel RF localization system offers the groundwork to design a radiotherapy-compatible patient positioning system for active motion compensation. PMID:27089342

  4. A Simulation Study of a Radiofrequency Localization System for Tracking Patient Motion in Radiotherapy.

    PubMed

    Ostyn, Mark; Kim, Siyong; Yeo, Woon-Hong

    2016-01-01

    One of the most widely used tools in cancer treatment is external beam radiotherapy. However, the major risk involved in radiotherapy is excess radiation dose to healthy tissue, exacerbated by patient motion. Here, we present a simulation study of a potential radiofrequency (RF) localization system designed to track intrafraction motion (target motion during the radiation treatment). This system includes skin-wearable RF beacons and an external tracking system. We develop an analytical model for direction of arrival measurement with radio frequencies (GHz range) for use in a localization estimate. We use a Monte Carlo simulation to investigate the relationship between a localization estimate and angular resolution of sensors (signal receivers) in a simulated room. The results indicate that the external sensor needs an angular resolution of about 0.03 degrees to achieve millimeter-level localization accuracy in a treatment room. This fundamental study of a novel RF localization system offers the groundwork to design a radiotherapy-compatible patient positioning system for active motion compensation. PMID:27089342

  5. [Radiotherapy for carcinoma of the cervix by intermittent sessions with deferred loading using Cobalt 60 or Caesium 137 (author's transl)].

    PubMed

    Swyngedauw, J

    1976-11-01

    Fractioning in gynaecological radiotherapy is a tolerance factor which may usefully be exploited in after loading. The advantage of fractioning is that it makes it possible to considerably increase the output of the projection apparatus (Curietron) and to avoid protection of the rooms : the patient retains the applicator in situ during the hospital stay and her bed is simply taken into the protected application room. With a source of 1 to 1.5 curie of cobalt, the author proposes twice-daily sessions of around ten minutes for ten days. Treatment may easily be given in the cobaltotherapy chamber. Using Caesium, it is necessary to protect only one room with a virtually two-fold increase in output since 10 to 12 hour treatments, either by day or by night, may be given. This very supple schedule makes it possible to modify dose and tolerance in relation to clinical conditions and the method of treatment (combined radiotherapy and surgery or radiotherapy alone). As far as axial vaginal source introducer is concerned, it is of prove, effectiveness as well as being easy to use. After describing the applicator, the source-carrier and the isodoses, the authors reviews the different methods of application, relying upon two previous studies of the influence of fractioning and protraction on tolerance (J. SWYNGEDAUW, 1975 and 1976).

  6. Decreasing Temporal Lobe Dose With Five-Field Intensity-Modulated Radiotherapy for Treatment of Pituitary Macroadenomas

    SciTech Connect

    Parhar, Preeti K.; Duckworth, Tamara; Shah, Parinda; DeWyngaert, J. Keith; Narayana, Ashwatha; Formenti, Silvia C.; Shah, Jinesh N.

    2010-10-01

    Purpose: To compare temporal lobe dose delivered by three pituitary macroadenoma irradiation techniques: three-field three-dimensional conformal radiotherapy (3D-CRT), three-field intensity-modulated radiotherapy (3F IMRT), and a proposed novel alternative of five-field IMRT (5F IMRT). Methods and Materials: Computed tomography-based external beam radiotherapy planning was performed for 15 pituitary macroadenoma patients treated at New York University between 2002 and 2007 using: 3D-CRT (two lateral, one midline superior anterior oblique [SAO] beams), 3F IMRT (same beam angles), and 5F IMRT (same beam angles with additional right SAO and left SAO beams). Prescription dose was 45 Gy. Target volumes were: gross tumor volume (GTV) = macroadenoma, clinical target volume (CTV) = GTV, and planning target volume = CTV + 0.5 cm. Structure contouring was performed by two radiation oncologists guided by an expert neuroradiologist. Results: Five-field IMRT yielded significantly decreased temporal lobe dose delivery compared with 3D-CRT and 3F IMRT. Temporal lobe sparing with 5F IMRT was most pronounced at intermediate doses: mean V25Gy (% of total temporal lobe volume receiving {>=}25 Gy) of 13% vs. 28% vs. 29% for right temporal lobe and 14% vs. 29% vs. 30% for left temporal lobe for 5F IMRT, 3D-CRT, and 3F IMRT, respectively (p < 10{sup -7} for 5F IMRT vs. 3D-CRT and 5F IMRT vs. 3F IMRT). Five-field IMRT plans did not compromise target coverage, exceed normal tissue dose constraints, or increase estimated brain integral dose. Conclusions: Five-field IMRT irradiation technique results in a statistically significant decrease in the dose to the temporal lobes and may thus help prevent neurocognitive sequelae in irradiated pituitary macroadenoma patients.

  7. Monte Carlo evaluation of tissue heterogeneities corrections in the treatment of head and neck cancer patients using stereotactic radiotherapy.

    PubMed

    Pokhrel, Damodar; McClinton, Christopher; Sood, Sumit; Badkul, Rajeev; Saleh, Habeeb; Jiang, Hongyu; Lominska, Christopher

    2016-01-01

    The purpose of this study was to generate Monte Carlo computed dose distributions with the X-ray voxel Monte Carlo (XVMC) algorithm in the treatment of head and neck cancer patients using stereotactic radiotherapy (SRT) and compare to heterogeneity corrected pencil-beam (PB-hete) algorithm. This study includes 10 head and neck cancer patients who underwent SRT re-irradiation using heterogeneity corrected pencil-beam (PB-hete) algorithm for dose calculation. Prescription dose was 24-40 Gy in 3-5 fractions (treated 3-5 fractions per week) with at least 95% of the PTV volume receiving 100% of the prescription dose. A stereotactic head and neck localization box was attached to the base of the thermoplastic mask fixation for target localization. The gross tumor volume (GTV) and organs-at-risk (OARs) were contoured on the 3D CT images. The planning target volume (PTV) was generated from the GTV with 0 to 5 mm uniform expansion; PTV ranged from 10.2 to 64.3 cc (average = 35.0±17.5 cc). OARs were contoured on the 3D planning CT and consisted of spinal cord, brainstem, optic structures, parotids, and skin. In the BrainLab treatment planning system (TPS), clinically optimal SRT plans were generated using hybrid planning technique (combination of 3D conformal nonco-planar arcs and nonopposing static beams) for the Novalis-Tx linear accelerator consisting of high-definition multileaf collimators (HD-MLCs: 2.5 mm leaf width at isocenter) and 6 MV-SRS (1000 MU/min) beam. For the purposes of this study, treatment plans were recomputed using XVMC algorithm utilizing identical beam geometry, multileaf positions, and monitor units and compared to the corresponding clinical PB-hete plans. The Monte Carlo calculated dose distributions show small decreases (< 1.5%) in calculated dose for D99, Dmean, and Dmax of the PTV coverage between the two algorithms. However, the average target volume encompassed by the prescribed percent dose (Vp) was about 2.5% less with XVMC vs. PB-hete and

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

    SciTech Connect

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

    2010-04-15

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

  9. SU-E-T-275: Radiobiological Evaluation of Intensity Modulated Radiotherapy Treatment for Locally Advanced Head and Neck Squamous Cell Carcinomas

    SciTech Connect

    Rekha Reddy, B.; Ravikumar, M.; Tanvir Pasha, C.R; Anil Kumar, M.R; Varatharaj, C.; Pyakuryal, A; Narayanasamy, Ganesh

    2014-06-01

    Purpose: To evaluate the radiobiological outcome of Intensity Modulated Radiotherapy Treatment (IMRT) for locally advanced head and neck squamous cell carcinomas using HART (Histogram Analysis in Radiation Therapy; J Appl Clin Med Phys 11(1): 137–157, 2010) program and compare with the clinical outcomes. Methods: We have treated 20 patients of stage III and IV HNSCC Oropharynx and hypopharynx with accelerated IMRT technique and concurrent chemotherapy. Delineation of tumor and normal tissues were done using Danish Head and Neck Cancer Group (DAHANCA) contouring guidelines and radiotherapy was delivered to a dose of 70Gy in 35 fractions to the primary and involved lymph nodes, 63Gy to intermediate risk areas and 56 Gy to lower risk areas, Monday to Saturday, 6 Days/week using 6 MV Photons with an expected overall treatment time of 6 weeks. The TCP and NTCP's were calculated from the dose-volume histogram (DVH) statistics using the Poisson Statistics (PS) and JT Lyman models respectively and the Resultwas correlated with clinical outcomes of the patients with mean follow up of 24 months. Results: Using HART program, the TCP (0.89± 0.01) of primary tumor and the NTCP for parotids (0.20±0.12), spinal cord (0.05±0.01), esophagus (0.30±0.2), mandible (0.35±0.21), Oral cavity (0.37±0.18), Larynx (0.30±0.15) were estimated and correlated with clinical outcome of the patients. Conclusion: Accelerated IMRT with Chemotherapy is a clinical feasible option in the treatment of locally advanced HNSCC with encouraging initial tumour response and acceptable acute toxicities. The correlation between the clinical outcomes and radiobiological model estimated parameters using HART programs are found to be satisfactory.

  10. Initial implementation of the conversion from the energy-subtracted CT number to electron density in tissue inhomogeneity corrections: An anthropomorphic phantom study of radiotherapy treatment planning

    SciTech Connect

    Tsukihara, Masayoshi; Noto, Yoshiyuki; Sasamoto, Ryuta; Hayakawa, Takahide; Saito, Masatoshi

    2015-03-15

    Purpose: To achieve accurate tissue inhomogeneity corrections in radiotherapy treatment planning, the authors had previously proposed a novel conversion of the energy-subtracted computed tomography (CT) number to an electron density (ΔHU–ρ{sub e} conversion), which provides a single linear relationship between ΔHU and ρ{sub e} over a wide range of ρ{sub e}. The purpose of this study is to present an initial implementation of the ΔHU–ρ{sub e} conversion method for a treatment planning system (TPS). In this paper, two example radiotherapy plans are used to evaluate the reliability of dose calculations in the ΔHU–ρ{sub e} conversion method. Methods: CT images were acquired using a clinical dual-source CT (DSCT) scanner operated in the dual-energy mode with two tube potential pairs and an additional tin (Sn) filter for the high-kV tube (80–140 kV/Sn and 100–140 kV/Sn). Single-energy CT using the same DSCT scanner was also performed at 120 kV to compare the ΔHU–ρ{sub e} conversion method with a conventional conversion from a CT number to ρ{sub e} (Hounsfield units, HU–ρ{sub e} conversion). Lookup tables for ρ{sub e} calibration were obtained from the CT image acquisitions for tissue substitutes in an electron density phantom (EDP). To investigate the beam-hardening effect on dosimetric uncertainties, two EDPs with different sizes (a body EDP and a head EDP) were used for the ρ{sub e} calibration. Each acquired lookup table was applied to two radiotherapy plans designed using the XiO TPS with the superposition algorithm for an anthropomorphic phantom. The first radiotherapy plan was for an oral cavity tumor and the second was for a lung tumor. Results: In both treatment plans, the performance of the ΔHU–ρ{sub e} conversion was superior to that of the conventional HU–ρ{sub e} conversion in terms of the reliability of dose calculations. Especially, for the oral tumor plan, which dealt with dentition and bony structures, treatment

  11. Measuring neutron spectra in radiotherapy using the nested neutron spectrometer

    SciTech Connect

    Maglieri, Robert Evans, Michael; Seuntjens, Jan; Kildea, John; Licea, Angel

    2015-11-15

    Purpose: Out-of-field neutron doses resulting from photonuclear interactions in the head of a linear accelerator pose an iatrogenic risk to patients and an occupational risk to personnel during radiotherapy. To quantify neutron production, in-room measurements have traditionally been carried out using Bonner sphere systems (BSS) with activation foils and TLDs. In this work, a recently developed active detector, the nested neutron spectrometer (NNS), was tested in radiotherapy bunkers. Methods: The NNS is designed for easy handling and is more practical than the traditional BSS. Operated in current-mode, the problem of pulse pileup due to high dose-rates is overcome by measuring current, similar to an ionization chamber. In a bunker housing a Varian Clinac 21EX, the performance of the NNS was evaluated in terms of reproducibility, linearity, and dose-rate effects. Using a custom maximum-likelihood expectation–maximization algorithm, measured neutron spectra at various locations inside the bunker were then compared to Monte Carlo simulations of an identical setup. In terms of dose, neutron ambient dose equivalents were calculated from the measured spectra and compared to bubble detector neutron dose equivalent measurements. Results: The NNS-measured spectra for neutrons at various locations in a treatment room were found to be consistent with expectations for both relative shape and absolute magnitude. Neutron fluence-rate decreased with distance from the source and the shape of the spectrum changed from a dominant fast neutron peak near the Linac head to a dominant thermal neutron peak in the moderating conditions of the maze. Monte Carlo data and NNS-measured spectra agreed within 30% at all locations except in the maze where the deviation was a maximum of 40%. Neutron ambient dose equivalents calculated from the authors’ measured spectra were consistent (one standard deviation) with bubble detector measurements in the treatment room. Conclusions: The NNS may

  12. Two-year longitudinal study of parotid salivary flow rates in head and neck cancer patients receiving unilateral neck parotid-sparing radiotherapy treatment.

    PubMed

    Henson, B S; Eisbruch, A; D'Hondt, E; Ship, J A

    1999-05-01

    Radiotherapy (RT) is a common treatment for head and neck cancers, and frequently causes permanent salivary dysfunction and xerostomia. This 2-year longitudinal study evaluated unstimulated and stimulated parotid flow rates in 11 patients with head and neck cancers who received unilateral neck parotid-sparing RT. The results demonstrated that treated parotid glands had essentially no output up to 2 years post-RT. Alternatively, spared parotid flow rates were indistinguishable from pre-RT values at 1 and 2 years post-RT, and increased slightly over time. Total unstimulated and stimulated parotid flow rates 2 years after completion of RT were similar to pre-RT values, suggesting that spared parotid function may compensate for lost function from treated parotid glands. These results demonstrate that unilateral neck parotid-sparing techniques are effective in preserving contralateral parotid glands up to 2 years after the completion of RT. PMID:10621842

  13. Reformulation of a clinical-dose system for carbon-ion radiotherapy treatment planning at the National Institute of Radiological Sciences, Japan.

    PubMed

    Inaniwa, Taku; Kanematsu, Nobuyuki; Matsufuji, Naruhiro; Kanai, Tatsuaki; Shirai, Toshiyuki; Noda, Koji; Tsuji, Hiroshi; Kamada, Tadashi; Tsujii, Hirohiko

    2015-04-21

    At the National Institute of Radiological Sciences (NIRS), more than 8,000 patients have been treated for various tumors with carbon-ion (C-ion) radiotherapy in the past 20 years based on a radiobiologically defined clinical-dose system. Through clinical experience, including extensive dose escalation studies, optimum dose-fractionation protocols have been established for respective tumors, which may be considered as the standards in C-ion radiotherapy. Although the therapeutic appropriateness of the clinical-dose system has been widely demonstrated by clinical results, the system incorporates several oversimplifications such as dose-independent relative biological effectiveness (RBE), empirical nuclear fragmentation model, and use of dose-averaged linear energy transfer to represent the spectrum of particles. We took the opportunity to update the clinical-dose system at the time we started clinical treatment with pencil beam scanning, a new beam delivery method, in 2011. The requirements for the updated system were to correct the oversimplifications made in the original system, while harmonizing with the original system to maintain the established dose-fractionation protocols. In the updated system, the radiation quality of the therapeutic C-ion beam was derived with Monte Carlo simulations, and its biological effectiveness was predicted with a theoretical model. We selected the most used C-ion beam with αr = 0.764 Gy(-1) and β = 0.0615 Gy(-2) as reference radiation for RBE. The C-equivalent biological dose distribution is designed to allow the prescribed survival of tumor cells of the human salivary gland (HSG) in entire spread-out Bragg peak (SOBP) region, with consideration to the dose dependence of the RBE. This C-equivalent biological dose distribution is scaled to a clinical dose distribution to harmonize with our clinical experiences with C-ion radiotherapy. Treatment plans were made with the original and the updated clinical-dose systems, and both

  14. Dosimetric Advantage of Intensity-Modulated Radiotherapy for Whole Ventricles in the Treatment of Localized Intracranial Germinoma

    SciTech Connect

    Sakanaka, Katsuyuki; Mizowaki, Takashi; Hiraoka, Masahiro

    2012-02-01

    Purpose: To investigate the dosimetric advantage of intensity-modulated radiotherapy (IMRT) for whole ventricles (WV) in patients with a localized intracranial germinoma receiving induction chemotherapy. Methods and Materials: Data from 12 consecutive patients with localized intracranial germinomas who received induction chemotherapy and radiotherapy were used. Four-field coplanar three-dimensional conformal radiotherapy (3D-CRT) and seven-field coplanar IMRT plans were created. In both plans, 24 Gy was prescribed in 12 fractions for the planning target volume (PTV) involving WV and tumor bed. In IMRT planning, optimization was conducted to reduce the doses to the organs at risk (OARs) as much as possible, keeping the minimum dose equivalent to that of 3D-CRT. The 3D-CRT and IMRT plans were compared in terms of the dose-volume statistics for target coverage and the OARs. Results: IMRT significantly increased the percentage volume of the PTV receiving 24 Gy compared with 3D-CRT (93.5% vs. 84.8%; p = 0.007), while keeping target homogeneity equivalent to 3D-CRT (p = 0.869). The absolute percentage reduction in the irradiated volume of the normal brain receiving 100%, 75%, 50%, and 25% of 24 Gy ranged from 0.7% to 16.0% in IMRT compared with 3D-CRT (p < 0.001). No significant difference was observed in the volume of the normal brain receiving 10% and 5% of 24 Gy between IMRT and 3D-CRT. Conformation number was significantly improved in IMRT (p < 0.001). For other OARs, the mean dose to the cochlea was reduced significantly in IMRT by 22.3% of 24 Gy compared with 3D-CRT (p < 0.001). Conclusions: Compared with 3D-CRT, IMRT for WV improved the target coverage and reduced the irradiated volume of the normal brain in patients with intracranial germinomas receiving induction chemotherapy. IMRT for WV with induction chemotherapy could reduce the late side effects from cranial irradiation without compromising control of the tumor.

  15. Whole Abdominopelvic Radiotherapy Using Intensity-Modulated Arc Therapy in the Palliative Treatment of Chemotherapy-Resistant Ovarian Cancer With Bulky Peritoneal Disease: A Single-Institution Experience

    SciTech Connect

    De Meerleer, Gert; Vandecasteele, Katrien; Ost, Piet; Delrue, Louke; Denys, Hannelore; Makar, Amin; Speleers, Bruno; Van Belle, Simon; Van den Broecke, Rudy; Fonteyne, Valerie; De Neve, Wilfried

    2011-03-01

    Purpose: To retrospectively review our experience with whole abdominopelvic radiotherapy (WAPRT) using intensity-modulated arc therapy in the palliative treatment of chemotherapy-resistant ovarian cancer with bulky peritoneal disease. Methods and Materials: Between April 2002 and April 2008, 13 patients were treated with WAPRT using intensity-modulated arc therapy. We prescribed a dose of 33 Gy to be delivered in 22 fractions of 1.5 Gy to the abdomen and pelvis. All patients had International Federation of Gynecology and Obstetrics Stage III or IV ovarian cancer at the initial diagnosis. At referral, the median age was 61 years, and the patients had been heavily pretreated with surgery and chemotherapy. All patients had symptoms from their disease, including gastrointestinal obstruction or subobstruction in 6, minor gastrointestinal symptoms in 2, pain in 4, ascites in 1, and vaginal bleeding in 2. A complete symptom or biochemical response required complete resolution of the patient's symptoms or cancer antigen-125 level. A partial response required {>=}50% resolution of these parameters. The actuarial survival was calculated from the start of radiotherapy. Results: The median overall survival was 21 weeks, with a 6-month overall survival rate of 45%. The 9 patients who completed treatment obtained a complete symptom response, except for ascites (partial response). The median and mean response duration (all symptoms grouped) was 24 and 37 weeks, respectively. Of the 6 patients presenting with obstruction or subobstruction, 4 obtained a complete symptom response (median duration, 16 weeks). Conclusion: WAPRT delivered using intensity-modulated arc therapy offers important palliation in the case of peritoneal metastatic ovarian cancer. WAPRT resolved intestinal obstruction for a substantial period.

  16. A dose calculation algorithm with correction for proton-nucleus interactions in non-water materials for proton radiotherapy treatment planning

    NASA Astrophysics Data System (ADS)

    Inaniwa, T.; Kanematsu, N.; Sato, S.; Kohno, R.

    2016-01-01

    In treatment planning for proton radiotherapy, the dose measured in water is applied to the patient dose calculation with density scaling by stopping power ratio {ρ\\text{S}} . Since the body tissues are chemically different from water, this approximation may cause dose calculation errors, especially due to differences in nuclear interactions. We proposed and validated an algorithm for correcting these errors. The dose in water is decomposed into three constituents according to the physical interactions of protons in water: the dose from primary protons continuously slowing down by electromagnetic interactions, the dose from protons scattered by elastic and/or inelastic interactions, and the dose resulting from nonelastic interactions. The proportions of the three dose constituents differ between body tissues and water. We determine correction factors for the proportion of dose constituents with Monte Carlo simulations in various standard body tissues, and formulated them as functions of their {ρ\\text{S}} for patient dose calculation. The influence of nuclear interactions on dose was assessed by comparing the Monte Carlo simulated dose and the uncorrected dose in common phantom materials. The influence around the Bragg peak amounted to  -6% for polytetrafluoroethylene and 0.3% for polyethylene. The validity of the correction method was confirmed by comparing the simulated and corrected doses in the materials. The deviation was below 0.8% for all materials. The accuracy of the correction factors derived with Monte Carlo simulations was separately verified through irradiation experiments with a 235 MeV proton beam using common phantom materials. The corrected doses agreed with the measurements within 0.4% for all materials except graphite. The influence on tumor dose was assessed in a prostate case. The dose reduction in the tumor was below 0.5%. Our results verify that this algorithm is practical and accurate for proton radiotherapy treatment planning, and

  17. Memory's Room.

    ERIC Educational Resources Information Center

    Carruthers, Mary

    1999-01-01

    Describes the Liberal Arts Studiolo from the Ducal Palace at Guibbio, Italy. Discusses how the room's design and decoration mirrors its educational uses. Notes that the object of education was to provide the young person with a kind of mental library of materials that could be drawn upon quickly. (RS)

  18. [Head and neck adaptive radiotherapy].

    PubMed

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

    2013-10-01

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

  19. 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.

  20. Fertility impairment in radiotherapy

    PubMed Central

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

    2016-01-01

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

  1. Fertility impairment in radiotherapy

    PubMed Central

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

    2016-01-01

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

  2. Fertility impairment in radiotherapy.

    PubMed

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

    2016-01-01

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

  3. Room-Temperature Chemical Solution Treatment for Flexible ZnS(O,OH)/Cu(In,Ga)Se2 Solar Cell: Improvements in Interface Properties and Metastability.

    PubMed

    Ho, Wei-Hao; Hsu, Chia-Hao; Yeh, Tzu-Hsuan; Chang, Yu-Han; Wei, Shih-Yuan; Lin, Tzu-Ying; Lai, Chih-Huang

    2016-03-01

    We demonstrate an effective room-temperature chemical solution treatment, by using thioacetamide (S treatment) or thioacetamide-InCl3 (In-S treatment) solution, on Cu(In,Ga)Se2 (CIGSe) surface to engineer the ZnS(O,OH)/CIGSe interface and junction quality, leading to enhanced efficiency and minimized metastability of flexible solar cells. The control device without treatment reveals a relatively low efficiency of 8.15%, which is significantly improved to 9.74% by In-S treatment, and 10.39% by S treatment. Results of X-ray photoelectron spectroscopy suggest that S is incorporated into CIGSe surface forming CIGSSe by S treatment, whereas a thin In-S layer is formed on CIGSe surface by In-S treatment with reduced amount of S diffusing into CIGSe. PL spectra and TRPL lifetime further reveal that S incorporation into CIGS surface may substitute the OSe and/or directly occupy the vacant anion site (VSe), resulting in the effective passivation of the recombination centers at CIGSe surface. Moreover, reducing the concentrations of VSe may thereby decrease the density of (VCu-VSe) acceptors, which can minimize the metastability of ZnS(O,OH)/CIGSe solar cells. With S treatment, the light soaking (LS) time of ZnS(O,OH)/CIGSe device is reduced approximately to one-half of control one. Our approach can be potentially applied for alternative Cd-free buffer layers to achieve high efficiency and low metastability. PMID:26905219

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

    PubMed

    Defourny, N; Lievens, Y

    2016-10-01

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

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

    PubMed

    Defourny, N; Lievens, Y

    2016-10-01

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

  6. Radiological protection in ion beam radiotherapy: practical guidance for clinical use of new technology.

    PubMed

    Yonekura, Y; Tsujii, H; Hopewell, J W; Ortiz López, P; Cosset, J-M; Paganetti, H; Montelius, A; Schardt, D; Jones, B; Nakamura, T

    2016-06-01

    Recently introduced technologies in radiotherapy have significantly improved the clinical outcome for patients. Ion beam radiotherapy, involving proton and carbon ion beams, provides excellent dose distributions in targeted tumours, with reduced doses to the surrounding normal tissues. However, careful treatment planning is required in order to maximise the treatment efficiency and minimise the dose to normal tissues. Radiation exposure from secondary neutrons and photons, particle fragments, and photons from activated materials should also be considered for radiological protection of the patient and medical staff. Appropriate maintenance is needed for the equipment and air in the treatment room, which may be activated by the particle beam and its secondary radiation. This new treatment requires complex procedures and careful adjustment of parameters for each patient. Therefore, education and training for the personnel involved in the procedure are essential for both effective treatment and patient protection. The International Commission on Radiological Protection (ICRP) has provided recommendations for radiological protection in ion beam radiotherapy in Publication 127 Medical staff should be aware of the possible risks resulting from inappropriate use and control of the equipment. They should also consider the necessary procedures for patient protection when new technologies are introduced into clinical practice.

  7. Radiological protection in ion beam radiotherapy: practical guidance for clinical use of new technology.

    PubMed

    Yonekura, Y; Tsujii, H; Hopewell, J W; Ortiz López, P; Cosset, J-M; Paganetti, H; Montelius, A; Schardt, D; Jones, B; Nakamura, T

    2016-06-01

    Recently introduced technologies in radiotherapy have significantly improved the clinical outcome for patients. Ion beam radiotherapy, involving proton and carbon ion beams, provides excellent dose distributions in targeted tumours, with reduced doses to the surrounding normal tissues. However, careful treatment planning is required in order to maximise the treatment efficiency and minimise the dose to normal tissues. Radiation exposure from secondary neutrons and photons, particle fragments, and photons from activated materials should also be considered for radiological protection of the patient and medical staff. Appropriate maintenance is needed for the equipment and air in the treatment room, which may be activated by the particle beam and its secondary radiation. This new treatment requires complex procedures and careful adjustment of parameters for each patient. Therefore, education and training for the personnel involved in the procedure are essential for both effective treatment and patient protection. The International Commission on Radiological Protection (ICRP) has provided recommendations for radiological protection in ion beam radiotherapy in Publication 127 Medical staff should be aware of the possible risks resulting from inappropriate use and control of the equipment. They should also consider the necessary procedures for patient protection when new technologies are introduced into clinical practice. PMID:26980799

  8. Medical Applications: Proton Radiotherapy

    NASA Astrophysics Data System (ADS)

    Keppel, Cynthia

    2009-05-01

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

  9. Clinical development of new drug-radiotherapy combinations.

    PubMed

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

    2016-10-01

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

  10. Dosimetric Comparison of Involved-Field Three-Dimensional Conformal Photon Radiotherapy and Breast-Sparing Proton Therapy for the Treatment of Hodgkin's Lymphoma in Female Pediatric Patients

    SciTech Connect

    Andolino, David L.; Hoene, Ted; Xiao, Lu; Buchsbaum, Jeffrey; Chang, Andrew L.

    2011-11-15

    Purpose: To assess the potential reduction in breast dose for young girls with Hodgkin's lymphoma (HL) treated with breast-sparing proton therapy (BS-PT) as compared with three-dimensional conformal involved-field photon radiotherapy (3D-CRT). Methods and Materials: The Clarian Health Cancer Registry was queried for female pediatric patients with the diagnosis of HL who received radiotherapy at the Indiana University Simon Cancer Center during 2006-2009. The original CT simulation images were obtained, and 3D-CRT and BS-PT plans delivering 21 Gy or cobalt gray equivalent (CGE) in 14 fractions were created for each patient. Dose-volume histogram data were collected for both 3D-CRT and BS-PT plans and compared by paired t test for correlated samples. Results: The cancer registry provided 10 female patients with Ann Arbor Stage II HL, aged 10-18 years at the time of treatment. Both mean and maximum breast dose were significantly less with BS-PT compared with 3D-CRT: 0.95 CGE vs. 4.70 Gy (p < 0.001) and 21.07 CGE vs. 23.11 Gy (p < 0.001), respectively. The volume of breast receiving 1.0 Gy/CGE and 5.0 Gy/CGE was also significantly less with BS-PT, 194 cm{sup 3} and 93 cm{sup 3}, respectively, compared with 790 cm{sup 3} and 360 cm{sup 3} with 3D-CRT (p = 0.009, 0.013). Conclusion: Breast-sparing proton therapy has the potential to reduce unnecessary breast dose in young girls with HL by as much as 80% relative to involved-field 3D-CRT.

  11. Three-Dimensional Non-Coplanar Conformal Radiotherapy Yields Better Results Than Traditional Beam Arrangements for Adjuvant Treatment of Gastric Cancer

    SciTech Connect

    Soyfer, Viacheslav Corn, Benjamin W.; Melamud, Alex B.S.; Alani, Shlomi; Tempelhof, Haim; Agai, Reuben; Shmueli, Anat; Figer, Arie; Kovner, Felix

    2007-10-01

    Purpose: The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields. Methods and Materials: A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field 'box' was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test. Results: The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan. Conclusion: Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical

  12. Is radiotherapy an effective treatment option for recurrent metastatic malignant melanoma? A case report of short-course, large-fraction radiation and a literature review

    PubMed Central

    Hallock, Abhirami; Vujovic, Olga; Yu, Edward

    2011-01-01

    BACKGROUND Malignant melanoma is regarded to be radiation resistant. A case of recurrent malignant melanoma with in-transit metastasis treated with short-course, high-fraction palliative radiation is presented to illustrate the effectiveness of radiotherapy. METHOD An 80-year-old woman initially treated surgically for a primary malignant melanoma of the left lower leg presented with multiple in-transit metastases. Palliative radiation was offered to treat two fungating in-transit masses that were resistant to treatments of isolated limb infusion and intralesional interleukin-2. RESULTS Treatment consisted of short-course, high-fraction radiation with 800 cGy fractions given over three weeks on days 0, 7 and 21, for a total dose of 2400 cGy. She experienced a complete response that was maintained for six months. CONCLUSIONS Radiation is an effective treatment option for palliation of recurrent malignant melanoma. Complete response is possible even with short-course, high-fraction radiation. PMID:23204890

  13. Expanding global access to radiotherapy.

    PubMed

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

    2015-09-01

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

  14. Expanding global access to radiotherapy.

    PubMed

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

    2015-09-01

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

  15. Pancreatic cancer: chemotherapy and radiotherapy

    PubMed Central

    Andrén-Sandberg, Åke

    2011-01-01

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

  16. Second Malignant Neoplasms Following Radiotherapy

    PubMed Central

    Kumar, Sanath

    2012-01-01

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

  17. Risk-adaptive radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Yusung

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

  18. [Cutaneous angiosarcoma arising after radiotherapy treatment of a breast carcinoma. Description of a case and review of the literature].

    PubMed

    Di Tommaso, L; Fabbri, A

    2003-08-01

    Cutaneous angiosarcomas occurring as a complication of radiation therapy for breast cancer are rare. To the best of our knowledge 37 cases have been reported in English literature during the last two decades. We describe a case of angiosarcoma arising in the skin of a breast previously irradiated for breast carcinoma. The patient, a 74-year-old woman, had been treated with conservative surgery and radiotherapy for a pT1N0 infiltrating ductal carcinoma of the left breast in 1993. Nine years later a skin lesion, which was interpreted as a recurrence, arose in the same site. A biopsy obtained from the lesion, and initially considered to be negative for cancer, showed istological features consistent with those of the atypical vascular lesion. Seven months later the same lesion transformed in a 5 x 3 reddish mass which at histological examination was diagnosed as an high grad post-irradiation angiosarcoma of the skin of the breast. Data on previously reported post iradiation angiosarcoma of the breast are reviewed; further consideration on differential diagnosis between those lesions and atypical vascular lesions are presented.

  19. Validation of nonrigid registration for multi-tracer PET-CT treatment planning in rectal cancer radiotherapy

    NASA Astrophysics Data System (ADS)

    Slagmolen, Pieter; Roels, Sarah; Loeckx, Dirk; Haustermans, Karin; Maes, Frederik

    2009-02-01

    The goal of radiotherapy is to deliver maximal dose to the tumor and minimal dose to the surrounding tissue. This requires accurate target definition. In sites were the tumor is difficult to see on the CT images, such as for rectal cancer, PET-CT imaging can be used to better define the target. If the information from multiple PETCT images with different tracers needs to be combined, a nonrigid registration is indispensable to compensate for rectal tissue deformations. Such registration is complicated by the presence of different volumes of bowel gas in the images to be registered. In this paper, we evaluate the performance of different nonrigid registration approaches by looking at the overlap of manually delineated rectum contours after registration. Using a B-spline transformation model, the results for two similarity measures, sum of squared differences and mutual information, either calculated over the entire image or on a region of interest are compared. Finally, we also assess the effect of the registration direction. We show that the combination of MI with a region of interest is best able to cope with residual rectal contrast and differences in bowel filling. We also show that for optimal performance the registration direction should be chosen depending on the difference in bowel filling in the images to be registered.

  20. Effective particle energies for stopping power calculation in radiotherapy treatment planning with protons and helium, carbon, and oxygen ions

    NASA Astrophysics Data System (ADS)

    Inaniwa, T.; Kanematsu, N.

    2016-10-01

    The stopping power ratio (SPR) of body tissues relative to water depends on the particle energy. For simplicity, however, most analytical dose planning systems do not account for SPR variation with particle energy along the beam’s path, but rather assume a constant energy for SPR estimation. The range error due to this simplification could be indispensable depending on the particle species and the assumed energy. This error can be minimized by assuming a suitable energy referred to as an ‘effective energy’ in SPR estimation. To date, however, the effective energy has never been investigated for realistic patient geometries. We investigated the effective energies for proton, helium-, carbon-, and oxygen-ion radiotherapy using volumetric models of the reference male and female phantoms provided by the International Commission on Radiological Protection (ICRP). The range errors were estimated by comparing the particle ranges calculated when particle energy variations were and were not considered. The effective energies per nucleon for protons and helium, carbon, and oxygen ions were 70 MeV, 70 MeV, 131 MeV, and 156 MeV, respectively. Using the determined effective energies, the range errors were reduced to  ⩽0.3 mm for respective particle species. For SPR estimation of multiple particle species, an effective energy of 100 MeV is recommended, with which the range error is  ⩽0.5 mm for all particle species.

  1. [Epoetin alfa in radiotherapy].

    PubMed

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

    1998-01-01

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

  2. Blisters - an unusual effect during radiotherapy.

    PubMed

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

    2013-11-01

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

  3. Treatment of left sided breast cancer for a patient with funnel chest: Volumetric-modulated arc therapy vs. 3D-CRT and intensity-modulated radiotherapy

    SciTech Connect

    Haertl, Petra M.; Pohl, Fabian; Weidner, Karin; Groeger, Christian; Koelbl, Oliver; Dobler, Barbara

    2013-04-01

    This case study presents a rare case of left-sided breast cancer in a patient with funnel chest, which is a technical challenge for radiation therapy planning. To identify the best treatment technique for this case, 3 techniques were compared: conventional tangential fields (3D conformal radiotherapy [3D-CRT]), intensity-modulated radiotherapy (IMRT), and volumetric-modulated arc therapy (VMAT). The plans were created for a SynergyS® (Elekta, Ltd, Crawley, UK) linear accelerator with a BeamModulator™ head and 6-MV photons. The planning system was Oncentra Masterplan® v3.3 SP1 (Nucletron BV, Veenendal, Netherlands). Calculations were performed with collapsed cone algorithm. Dose prescription was 50.4 Gy to the average of the planning target volume (PTV). PTV coverage and homogeneity was comparable for all techniques. VMAT allowed reducing dose to the ipsilateral organs at risk (OAR) and the contralateral breast compared with IMRT and 3D-CRT: The volume of the left lung receiving 20 Gy was 19.3% for VMAT, 26.1% for IMRT, and 32.4% for 3D-CRT. In the heart, a D{sub 15%} of 9.7 Gy could be achieved with VMAT compared with 14 Gy for IMRT and 46 Gy for 3D-CRT. In the contralateral breast, D{sub 15%} was 6.4 Gy for VMAT, 8.8 Gy for IMRT, and 10.2 Gy for 3D-CRT. In the contralateral lung, however, the lowest dose was achieved with 3D-CRT with D{sub 10%} of 1.7 Gy for 3D-CRT, and 6.7 Gy for both IMRT and VMAT. The lowest number of monitor units (MU) per 1.8-Gy fraction was required by 3D-CRT (192 MU) followed by VMAT (518 MU) and IMRT (727 MU). Treatment time was similar for 3D-CRT (3 min) and VMAT (4 min) but substantially increased for IMRT (13 min). VMAT is considered the best treatment option for the presented case of a patient with funnel chest. It allows reducing dose in most OAR without compromising target coverage, keeping delivery time well below 5 minutes.

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

    PubMed Central

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

    2013-01-01

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

  5. Radiotherapy in patients with connective tissue diseases.

    PubMed

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

    2016-03-01

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

  6. SU-E-T-547: A Method to Correlate Treatment Planning Issue with Clinical Analysis for Prostate Stereotactic Body Radiotherapy (SBRT)

    SciTech Connect

    Li, K; Jung, E; Newton, J; Cornell, D; Able, A

    2014-06-01

    Purpose: In this study, the algorithms and calculation setting effect and contribution weighing on prostate Volumetric Modulated Arc Therapy (VMAT) based SBRT were evaluated for clinical analysis. Methods: A low risk prostate patient under SBRT was selected for the treatment planning evaluation. The treatment target was divided into low dose prescription target volume (PTV) and high Dose PTV. Normal tissue constraints include urethra and femur head, and rectum was separated into anterior, lateral and posterior parts. By varying the constraint limit of treatment plan calculation setting and algorithms, the effect on dose coverage and normal tissue dose constraint parameter carried effective comparison for the nominal prescription and constraint. For each setting, their percentage differences to the nominal value were calculated with geometric mean and harmonic mean. Results: In the arbitrary prostate SBRT case, 14 variables were selected for this evaluation by using nominal prescription and constraint. Six VMAT planning settings were anisotropic analytic algorithm stereotactic beam with and without couch structure in grid size of 1mm and 2mm, non stereotactic beam, Acuros algorithm . Their geometry means of the variable sets for these plans were 112.3%, 111.9%, 112.09%, 111.75%, 111.28%, and 112.05%. And the corresponding harmonic means were 2.02%, 2.16%, 3.15%, 4.74%, 5.47% and 5.55%. Conclusions: In this study, the algorithm difference shows relatively larger harmonic mean between prostate SBRT VMAT plans. This study provides a methodology to find sensitive combined variables related to clinical analysis, and similar approach could be applied to the whole treatment procedure from simulation to treatment in radiotherapy for big clinical data analysis.

  7. Practical aspects and uncertainty analysis of biological effective dose (BED) regarding its three-dimensional calculation in multiphase radiotherapy treatment plans

    SciTech Connect

    Kauweloa, Kevin I. Gutierrez, Alonso N.; Bergamo, Angelo; Stathakis, Sotirios; Papanikolaou, Nikos; Mavroidis, Panayiotis

    2014-07-15

    Purpose: There is a growing interest in the radiation oncology community to use the biological effective dose (BED) rather than the physical dose (PD) in treatment plan evaluation and optimization due to its stronger correlation with radiobiological effects. Radiotherapy patients may receive treatments involving a single only phase or multiple phases (e.g., primary and boost). Since most treatment planning systems cannot calculate the analytical BED distribution in multiphase treatments, an approximate multiphase BED expression, which is based on the total physical dose distribution, has been used. The purpose of this paper is to reveal the mathematical properties of the approximate BED formulation, relative to the true BED. Methods: The mathematical properties of the approximate multiphase BED equation are analyzed and evaluated. In order to better understand the accuracy of the approximate multiphase BED equation, the true multiphase BED equation was derived and the mathematical differences between the true and approximate multiphase BED equations were determined. The magnitude of its inaccuracies under common clinical circumstances was also studied. All calculations were performed on a voxel-by-voxel basis using the three-dimensional dose matrices. Results: Results showed that the approximate multiphase BED equation is accurate only when the dose-per-fractions (DPFs) in both the first and second phases are equal, which occur when the dose distribution does not significantly change between the phases. In the case of heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the inaccuracy of the approximate multiphase BED is greater. These characteristics are usually seen in the dose distributions being delivered to organs at risk rather than to targets. Conclusions: The finding of this study indicates that the true multiphase BED equation should be implemented in the treatment planning

  8. DOSE TO RADIOLOGICAL TECHNOLOGISTS FROM INDUCED RADIONUCLIDES IN CARBON ION RADIOTHERAPY.

    PubMed

    Yonai, S; Spano, V

    2016-09-01

    Radioactive nuclides are induced in irradiation devices and patients during high-energy photon and ion beam radiotherapies. These nuclides potentially become sources of exposure to radiation workers. Radiological technologists (RTs) are often required to enter an irradiation room and approach activated devices and patients. In this study, annual doses to RTs working in a carbon ion radiotherapy facility were estimated based on measurements with the Si-semiconductor personal dosemeter. In addition, the time decay of dose around a patient couch after irradiation was obtained by phantom experiments. The annual Hp(10) values for passive and scanned beams were estimated to be 61 and 2 μSv, respectively, when assuming the number of treatments in 2013. These are much lower than the ICRP recommended dose limit for radiation workers. The time-series data of dose to RTs during their work and the time decay of the dose should be helpful for reducing their dose further. PMID:27179122

  9. Radiotherapy in the management of early breast cancer

    SciTech Connect

    Wang, Wei

    2013-03-15

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

  10. Effect of combined treatment with salvage radiotherapy plus androgen suppression on quality of life in patients with recurrent prostate cancer after radical prostatectomy

    SciTech Connect

    Pearce, Andrew; Choo, Richard . E-mail: choo.c@mayo.edu; Danjoux, Cyril; Morton, Gerard; Loblaw, D. Andrew; Szumacher, Ewa; Cheung, Patrick; Deboer, Gerrit; Chander, Sarat

    2006-05-01

    Purpose: To examine the effect of salvage radiotherapy (RT) plus 2-year androgen suppression (AS) on quality of life (QOL). Methods and Materials: A total of 74 patients with biopsy-proven local recurrence or PSA relapse after radical prostatectomy were treated with salvage RT plus 2-year AS, as per a phase II study. Quality of life was prospectively assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire 30-Item Version 3.0 with the added prostate cancer-specific module at baseline and predefined follow-up visits. Results: Patients experienced a significant increase in bowel dysfunction (23%) by the end of RT (p < 0.0001). This bowel dysfunction improved after RT but remained slightly elevated (5-10%) throughout the 2-year AS period. This extent of residual bowel dysfunction would be considered of minimal clinical importance. A similar, but less pronounced, pattern of change did occur for urinary dysfunction. Erectile function showed no change during RT, but had an abrupt decline (10%) with initiation of AS that was of moderate clinical significance (p < 0.01). None of the other QOL domains demonstrated a persistent, significant change from baseline that would be considered of major clinical significance. Conclusion: The combined treatment with salvage RT plus 2-year AS had relatively minor long-term effects on QOL.

  11. Random Positional Variation Among the Skull, Mandible, and Cervical Spine With Treatment Progression During Head-and-Neck Radiotherapy

    S