Pregnancy and radiotherapy for breast cancer

International Nuclear Information System (INIS)

Karasawa, Kumiko

2013-01-01

Cancer in pregnancy is relatively uncommon but breast cancer is one of the most common malignancy occur with pregnancy. Prescribed doses of radiotherapy are significantly higher than those of diagnostic procedures. Fetal exposure and damage can occur during radiotherapy within target area. Because of those risks, radiotherapy during pregnancy is basically has to avoid. Even though, feral damage depends on fetal dose and has some threshold dose. Practically, even in stochastic effect, there are some minimal doses. A most important point is careful estimation of fetal dose before radiation. The physician has to inform the patient about risk and benefit of radiotherapy to fetus and to mother and have an ethical balance to help the mother and family to make a final decision. (author)

Intraoperative Boost Radiotherapy during Targeted Oncoplastic Breast Surgery: Overview and Single Center Experiences

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Wolfram Malter

2014-01-01

Full Text Available Breast-conserving surgery followed by whole-breast irradiation is the standard local therapy for early breast cancer. The international discussion of reduced importance of wider tumor-free resection margins than “tumor not touching ink” leads to the development of five principles in targeted oncoplastic breast surgery. IORT improves local recurrence risk and diminishes toxicity since there is less irradiation of healthy tissue. Intraoperative radiotherapy (IORT can be delivered in two settings: an IORT boost followed by a conventional regimen of external beam radiotherapy or a single IORT dose. The data from TARGIT-A and ELIOT reinforce the conviction that intraoperative radiotherapy during breast-conserving surgery is a reliable alternative to conventional postoperative fractionated irradiation, but only in a carefully selected population at low risk of local recurrence. We describe our experiences with IORT boost (50 kV energy X-rays; 20 Gy in combination with targeted oncoplastic breast surgery in a routine clinical setting. Our experiences demonstrate the applicability and reliability of combining IORT boost with targeted oncoplastic breast surgery in breast-conserving therapy of early breast cancer.

Biological evaluation and molecular docking of Rhein as a multi-targeted radiotherapy sensitization agent of nasopharyngeal carcinoma

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Su, Zhengying; Tian, Wei; Li, Jing; Wang, Chunmiao; Pan, Zhiyu; Li, Danrong; Hou, Huaxin

2017-11-01

Radiation resistance of nasopharyngeal carcinoma (NPC) is a joint effect caused by complex molecular mechanisms. The development of multi-target radiotherapy sensitization agents offered a promising method for the treatment of NPC. In this work, the probability of Rhein to be a multi-target radiotherapy sensitization agent was explored through computer aid virtual screening by inverse docking study. In order to validate the accuracy of the computational results, radiotherapy sensitization of Rhein to NPC cells and its effects on the expression of target proteins were evaluated separately by CCK8 assay and Western blotting analysis. Our result demonstrated that Rhein possessed strong binding affinity with RAC1 and HSP90. No cytotoxic concentration of Rhein had radiosensitization effect on nasopharyngeal carcinoma CNE1 cells. After treatment with Rhein and 2Gy radiation, the expression of RAC1 upregulated and the expression of HSP90 down-regulated in cells. Based on the above data, Rhein is likely to become an attractive lead compound for the future design of multi-target radiotherapy sensitization agents.

Characterization of Target Volume Changes During Breast Radiotherapy Using Implanted Fiducial Markers and Portal Imaging

International Nuclear Information System (INIS)

Harris, Emma J.; Donovan, Ellen M.; Yarnold, John R.; Coles, Charlotte E.; Evans, Philip M.

2009-01-01

Purpose: To determine target volume changes by using volume and shape analysis for patients receiving radiotherapy after breast conservation surgery and to compare different methods of automatically identifying changes in target volume, position, size, and shape during radiotherapy for use in adaptive radiotherapy. Methods and Materials: Eleven patients undergoing whole breast radiotherapy had fiducial markers sutured into the excision cavity at the time of surgery. Patients underwent imaging using computed tomography (for planning and at the end of treatment) and during treatment by using portal imaging. A marker volume (MV) was defined by using the measured marker positions. Changes in both individual marker positions and MVs were identified manually and using six automated similarity indices. Comparison of the two types of analysis (manual and automated) was undertaken to establish whether similarity indices can be used to automatically detect changes in target volumes. Results: Manual analysis showed that 3 patients had significant MV reduction. This analysis also showed significant changes between planning computed tomography and the start of treatment for 9 patients, including single and multiple marker movement, deformation (shape change), and rotation. Four of the six similarity indices were shown to be sensitive to the observed changes. Conclusions: Significant changes in size, shape, and position occur to the fiducial marker-defined volume. Four similarity indices can be used to identify these changes, and a protocol for their use in adaptive radiotherapy is suggested

Radiotherapy in combination with vascular-targeted therapies

International Nuclear Information System (INIS)

Ciric, Eva; Sersa, Gregor

2010-01-01

Given the critical role of tumor vasculature in tumor development, considerable efforts have been spent on developing therapeutic strategies targeting the tumor vascular network. A variety of agents have been developed, with two general approaches being pursued. Antiangiogenic agents (AAs) aim to interfere with the process of angiogenesis, preventing new tumor blood vessel formation. Vascular-disrupting agents (VDAs) target existing tumor vessels causing tumor ischemia and necrosis. Despite their great therapeutic potential, it has become clear that their greatest clinical utility may lie in combination with conventional anticancer therapies. Radiotherapy is a widely used treatment modality for cancer with its distinct therapeutic challenges. Thus, combining the two approaches seems reasonable. Strong biological rationale exist for combining vascular-targeted therapies with radiation. AAs and VDAs were shown to alter the tumor microenvironment in such a way as to enhance responses to radiation. The results of preclinical and early clinical studies have confirmed the therapeutic potential of this new treatment strategy in the clinical setting. However, concerns about increased normal tissue toxicity, have been raised

Integration of multidisciplinary technologies for real time target visualization and verification for radiotherapy.

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Chang, Wen-Chung; Chen, Chin-Sheng; Tai, Hung-Chi; Liu, Chia-Yuan; Chen, Yu-Jen

2014-01-01

The current practice of radiotherapy examines target coverage solely from digitally reconstructed beam's eye view (BEV) in a way that is indirectly accessible and that is not in real time. We aimed to visualize treatment targets in real time from each BEV. The image data of phantom or patients from ultrasound (US) and computed tomography (CT) scans were captured to perform image registration. We integrated US, CT, US/CT image registration, robotic manipulation of US, a radiation treatment planning system, and a linear accelerator to constitute an innovative target visualization system. The performance of this algorithm segmented the target organ in CT images, transformed and reconstructed US images to match each orientation, and generated image registration in real time mode with acceptable accuracy. This image transformation allowed physicians to visualize the CT image-reconstructed target via a US probe outside the BEV that was non-coplanar to the beam's plane. It allowed the physicians to remotely control the US probe that was equipped on a robotic arm to dynamically trace and real time monitor the coverage of the target within the BEV during a simulated beam-on situation. This target visualization system may provide a direct remotely accessible and real time way to visualize, verify, and ensure tumor targeting during radiotherapy.

Variation in radiotherapy target volume definition, dose to organs at risk and clinical target volumes using anatomic (computed tomography) versus combined anatomic and molecular imaging (positron emission tomography/computed tomography): intensity-modulated radiotherapy delivered using a tomotherapy Hi Art machine: final results of the VortigERN study.

Science.gov (United States)

Chatterjee, S; Frew, J; Mott, J; McCallum, H; Stevenson, P; Maxwell, R; Wilsdon, J; Kelly, C G

2012-12-01

Contrast-enhanced computed tomography (CECT) is the current standard for delineating tumours of the head and neck for radiotherapy. Although metabolic imaging with positron emission tomography (PET) has been used in recent years, the studies were non-confirmatory in establishing its routine role in radiotherapy planning in the modern era. This study explored the difference in gross tumour volume and clinical target volume definitions for the primary and nodal volumes when FDG PET/CT was used as compared with CECT in oropharyngeal cancer cases. Twenty patients with oropharyngeal cancers had a PET/CT scan in the treatment position after consent. Target volumes were defined on CECT scans by a consultant clinical oncologist who was blind to the PET scans. After obtaining inputs from a radiologist, another set of target volumes were outlined on the PET/CT data set. The gross and clinical target volumes as defined on the two data sets were then analysed. The hypothesis of more accurate target delineation, preventing geographical miss and comparative overlap volumes between CECT and PET/CT, was explored. The study also analysed the volumes of intersection and analysed whether there was any TNM stage migration when PET/CT was used as compared with CECT for planning. In 17 of 20 patients, the TNM stage was not altered when adding FDG PET information to CT. PET information prevented geographical miss in two patients and identified distant metastases in one case. PET/CT gross tumour volumes were smaller than CECT volumes (mean ± standard deviation: 25.16 cm(3) ± 35.8 versus 36.56 cm(3) ± 44.14; P standard deviation: CECT versus PET/CT 32.48 cm(3) ± 36.63 versus 32.21 cm(3) ± 37.09; P > 0.86) were not statistically different. Similarity and discordance coefficients were calculated and are reported. PET/CT as compared with CECT could provide more clinically relevant information and prevent geographical miss when used for radiotherapy planning for advanced oropharyngeal

4D imaging for target definition in stereotactic radiotherapy for lung cancer.

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Slotman, Ben J; Lagerwaard, Frank J; Senan, Suresh

2006-01-01

Stereotactic radiotherapy of Stage I lung tumors has been reported to result in high local control rates that are far superior to those obtained with conventional radiotherapy techniques, and which approach those achieved with primary surgery. Breathing-induced motion of tumor and target tissues is an important issue in this technique and careful attention should be paid to the contouring and the generation of individualized margins. We describe our experience with the use of 4DCT scanning for this group of patients, the use of post-processing tools and the potential benefits of respiratory gating.

The distribution of alternative agents for targeted radiotherapy within human neuroblastoma spheroids

International Nuclear Information System (INIS)

Mairs, R.J.; Gaze, M.N.; Murray, T.; Reid, R.; McSharry, C.; Babich, J.W.

1991-01-01

This study aims to select the radiopharmaceutical vehicle for targeted radiotherapy of neuroblastoma which is most likely to penetrate readily the centre of micrometastases in vivo. The human neuroblastoma cell line NB1-G, grown as multicellular spheroids provided an in vitro model for micrometastases. The radiopharmaceuticals studied were the catecholamine analogue metaiodobenzyl guanidine (mIBG), a specific neuroectodermal monoclonal antibody (UJ13A) and β nerve growth factor (βNGF). Following incubation of each drug with neuroblastoma spheroids, autoradiographs of frozen sections were prepared to demonstrate their relative distributions. mIBG and βNGF were found to penetrate the centre of spheroids readily although the concentration of mIBG greatly exceeded that of βNGF. In contrast, UJ13A was only bound peripherally. We conclude that mIBG is the best available vehicle for targeted radiotherapy of neuroblastoma cells with active uptake mechanisms for catecholimines. It is suggested that radionuclides with a shorter range of emissions than 131 I may be conjugated to benzyl guanidine to constitute more effective targeting agents with potentially less toxicity to adjacent normal tissues. (author)

Targeted intraoperative radiotherapy (TARGIT) yields very low recurrence rates when given as a boost

International Nuclear Information System (INIS)

Vaidya, Jayant S.; Baum, Michael; Tobias, Jeffrey S.; Massarut, Samuele; Wenz, Frederik; Murphy, Olive; Hilaris, Basil; Houghton, Joan B.Sc.; Saunders, Christobel; Corica, Tammy; Roncadin, Mario; Kraus-Tiefenbacher, Uta; Melchaert, Frank; Keshtgar, Mohammed; Sainsbury, Richard; Douek, Michael; Harrison, Elly; Thompson, Alastair; Joseph, David

2006-01-01

Purpose: Patients undergoing breast-conserving surgery were offered boost radiotherapy with targeted intraoperative radiotherapy (TARGIT) using the Intrabeam system to test the feasibility, safety, and efficacy of the new approach. Methods and Materials: We treated 302 cancers in 301 unselected patients. This was not a low-risk group. One-third of patients (98/301) were younger than 51 years of age. More than half of the tumors (172, 57%) were between 1 cm and 2 cm, and one-fifth (62, 21%) were >2 cm; 29% (86) had a Grade 3 tumor and, in 29% (87), axillary lymph nodes contained metastasis. After primary surgery, 20 Gy was delivered intraoperatively to the surface of the tumor bed, followed by external-beam radiotherapy (EBRT), but excluding the usual boost. Results: The treatment was well tolerated. The follow-up ranged from 3 to 80 months (164 and 90 patients completed 2 and 3 years follow-up, respectively). Four patients (1.3%) had local recurrence. The Kaplan-Meier estimate of local recurrence is 2.6% (SE = 1.7) at 5 years. This compares favorably with the 4.3% recurrence rate in boosted patients from the EORTC boost study, in which only 8.1% patients were node-positive, as opposed to 29% in our series. Conclusion: Targeted intraoperative radiotherapy combined with EBRT results in a low local recurrence rate. This could be attributed to both accurate targeting and timeliness of the treatment. These data support the need for a randomized trial to test whether the TARGIT boost is superior to conventional external boost, especially in high-risk women

Long-Term Results of Targeted Intraoperative Radiotherapy (Targit) Boost During Breast-Conserving Surgery

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Vaidya, Jayant S., E-mail: jayant.vaidya@ucl.ac.uk [Research Department of Surgery, Division of Surgery and Interventional Science, University College London, London (United Kingdom); Baum, Michael [Research Department of Surgery, Division of Surgery and Interventional Science, University College London, London (United Kingdom); Tobias, Jeffrey S. [Department of Radiation Oncology, University College London Hospitals, London (United Kingdom); Wenz, Frederik [Radiation Oncology and Gynaecology, University Medical Centre of Mannheim (Germany); Massarut, Samuele [Surgery and Radiation Oncology, Centro di Riferimento Oncologico (CRO), Aviano (Italy); Keshtgar, Mohammed [Research Department of Surgery, Division of Surgery and Interventional Science, University College London, London (United Kingdom); Hilaris, Basil [Radiation Oncology, Our Lady of Mercy, New York Medical College, New York (United States); Saunders, Christobel [Institute of Health and Rehabilitation Research, University of Notre Dame, Fremantle, Western Australia (Australia); Williams, Norman R.; Brew-Graves, Chris [Research Department of Surgery, Division of Surgery and Interventional Science, University College London, London (United Kingdom); Corica, Tammy [Institute of Health and Rehabilitation Research, University of Notre Dame, Fremantle, Western Australia (Australia); Roncadin, Mario [Surgery and Radiation Oncology, Centro di Riferimento Oncologico (CRO), Aviano (Italy); Kraus-Tiefenbacher, Uta; Suetterlin, Marc [Radiation Oncology and Gynaecology, University Medical Centre of Mannheim (Germany); Bulsara, Max [Institute of Health and Rehabilitation Research, University of Notre Dame, Fremantle, Western Australia (Australia); Joseph, David [Radiation Oncology, Sir Charles Gairdner Hospital and School of Surgery, University of Western Australia, Perth (Australia)

2011-11-15

Purpose: We have previously shown that delivering targeted radiotherapy to the tumour bed intraoperatively is feasible and desirable. In this study, we report on the feasibility, safety, and long-term efficacy of TARGeted Intraoperative radioTherapy (Targit), using the Intrabeam system. Methods and Materials: A total of 300 cancers in 299 unselected patients underwent breast-conserving surgery and Targit as a boost to the tumor bed. After lumpectomy, a single dose of 20 Gy was delivered intraoperatively. Postoperative external beam whole-breast radiotherapy excluded the usual boost. We also performed a novel individualized case control (ICC) analysis that computed the expected recurrences for the cohort by estimating the risk of recurrence for each patient using their characteristics and follow-up period. Results: The treatment was well tolerated. The median follow up was 60.5 months (range, 10-122 months). Eight patients have had ipsilateral recurrence: 5-year Kaplan Meier estimate for ipsilateral recurrence is 1.73% (SE 0.77), which compares well with that seen in the boosted patients in the European Organization for Research and Treatment of Cancer study (4.3%) and the UK STAndardisation of breast RadioTherapy study (2.8%). In a novel ICC analysis of 242 of the patients, we estimated that there should be 11.4 recurrences; in this group, only 6 recurrences were observed. Conclusions: Lumpectomy and Targit boost combined with external beam radiotherapy results in a low local recurrence rate in a standard risk patient population. Accurate localization and the immediacy of the treatment that has a favorable effect on tumour microenvironment may contribute to this effect. These long-term data establish the long-term safety and efficacy of the Targit technique and generate the hypothesis that Targit boost might be superior to an external beam boost in its efficacy and justifies a randomized trial.

Guidelines for target volume definition in post-operative radiotherapy for prostate cancer, on behalf of the EORTC Radiation Oncology Group

International Nuclear Information System (INIS)

Poortmans, Philip; Bossi, Alberto; Vandeputte, Katia; Bosset, Mathieu; Miralbell, Raymond; Maingon, Philippe; Boehmer, Dirk; Budiharto, Tom; Symon, Zvi; Bergh, Alfons C.M. van den; Scrase, Christopher; Poppel, Hendrik van; Bolla, Michel

2007-01-01

The appropriate application of 3-D conformal radiotherapy, intensity modulated radiotherapy or image guided radiotherapy for patients undergoing post-operative radiotherapy for prostate cancer requires a standardisation of the target volume definition and delineation as well as standardisation of the clinical quality assurance procedures. Recommendations for this are presented on behalf of the European Organisation for Research and Treatment of Cancer (EORTC) Radiation Oncology Group and in addition to the already published guidelines for radiotherapy as the primary treatment

Review of potential improvements using MRI in the radiotherapy workflow

International Nuclear Information System (INIS)

Torresin, Alberto; Brambilla, Maria Grazia; Monti, Angelo F.; Moscato, Alessio; Brockmann, Marc A.; University Medical Center Mannheim; Schad, Lothar; Attenberger, Ulrike I.; Lohr, Frank

2015-01-01

The goal of modern radiotherapy is to deliver a lethal amount of dose to tissue volumes that contain a significant amount of tumour cells while sparing surrounding unaffected or healthy tissue. Online image guided radiotherapy with stereotactic ultrasound, fiducial-based planar X-ray imaging or helical/conebeam CT has dramatically improved the precision of radiotherapy, with moving targets still posing some methodical problems regarding positioning. Therefore, requirements for precise target delineation and identification of functional body structures to be spared by high doses become more evident. The identification of areas of relatively radioresistant cells or areas of high tumor cell density is currently under development. This review outlines the state of the art of MRI integration into treatment planning and its importance in follow up and the quantification of biological effects. Finally the current state of the art of online imaging for patient positioning will be outlined and indications will be given what the potential of integrated radiotherapy/online MRI systems is.

Target migration from re-inflation of adjacent atelectasis during lung stereotactic body radiotherapy.

Science.gov (United States)

Mao, Bijing; Verma, Vivek; Zheng, Dandan; Zhu, Xiaofeng; Bennion, Nathan R; Bhirud, Abhijeet R; Poole, Maria A; Zhen, Weining

2017-06-10

Stereotactic body radiotherapy (SBRT) is a widely accepted option for the treatment of medically inoperable early-stage non-small cell lung cancer (NSCLC). Herein, we highlight the importance of interfraction image guidance during SBRT. We describe a case of early-stage NSCLC associated with segmental atelectasis that translocated 15 mm anteroinferiorly due to re-expansion of the adjacent segmental atelectasis following the first fraction. The case exemplifies the importance of cross-sectional image-guided radiotherapy that shows the intended target, as opposed to aligning based on rigid anatomy alone, especially in cases associated with potentially "volatile" anatomic areas.

Development of radiation oncology learning system combined with multi-institutional radiotherapy database (ROGAD)

International Nuclear Information System (INIS)

Takemura, Akihiro; Iinuma, Masahiro; Kou, Hiroko; Harauchi, Hajime; Inamura, Kiyonari

1999-01-01

We have constructed and are operating a multi-institutional radiotherapy database ROGAD (Radiation Oncology Greater Area Database) since 1992. One of it's purpose is 'to optimize individual radiotherapy plans'. We developed Radiation oncology learning system combined with ROGAD' which conforms to that purpose. Several medical doctors evaluated our system. According to those evaluations, we are now confident that our system is able to contribute to improvement of radiotherapy results. Our final target is to generate a good cyclic relationship among three components: radiotherapy results according to ''Radiation oncology learning system combined with ROGAD.'; The growth of ROGAD; and radiation oncology learning system. (author)

Value of 18F-FDG PET-CT in nasopharyngeal carcinoma target delineation and radiotherapy boost

International Nuclear Information System (INIS)

Wang Ying; Feng Yanlin

2011-01-01

18 F-FDG PET-CT has widely used in nasopharyngeal carcinoma diagnosis and staging in recent years, it's effecten target volume delineation has received great attention. The article lays stress on the clinical research progress of 18 F-FDG PET-CT in the radiotherapy of nasopharyngeal carcinoma improve the accuracy of target delineation, reduce the difference of target delineation, guide the dose painting and boost. (authors)

A consensus-based guideline defining clinical target volume for primary disease in external beam radiotherapy for intact uterine cervical cancer

International Nuclear Information System (INIS)

Toita, Takafumi; Ohno, Tatsuya; Kaneyasu, Yuko

2011-01-01

The objective of this study was to develop a consensus-based guideline to define clinical target volume for primary disease (clinical target volume primary) in external beam radiotherapy for intact uterine cervical cancer. The working subgroup of the Japan Clinical Oncology Group (JCOG) Radiation Therapy Study Group began developing a guideline for primary clinical target volume in November 2009. The group consisted of 10 radiation oncologists and 2 gynecologic oncologists. The process started with comparing the contouring on computed tomographic images of actual cervical cancer cases among the members. This was followed by a comprehensive literature review that included primary research articles and textbooks as well as information on surgical procedures. Extensive discussion occurred in face-to-face meetings (three occasions) and frequent e-mail communications until a consensus was reached. The working subgroup reached a consensus on the definition for the clinical target volume primary. The clinical target volume primary consists of the gross tumor volume, uterine cervix, uterine corpus, parametrium, vagina and ovaries. Definitions for these component structures were determined. Anatomical boundaries in all directions were defined for the parametrium. Examples delineating these boundaries were prepared for the posterior border of the parametrium for various clinical situations (id est (i.e.) central tumor bulk, degree of parametrial involvement). A consensus-based guideline defining the clinical target volume primary was developed for external beam radiotherapy for intact uterine cervical cancer. This guideline will serve as a template for radiotherapy protocols in future clinical trials. It may also be used in actual clinical practice in the setting of highly precise external beam radiotherapy, including intensity-modulated radiotherapy. (author)

New Language and Old Problems in Breast Cancer Radiotherapy.

Science.gov (United States)

Chiricuţă, Ion Christian

2017-01-01

New developments in breast cancer radiotherapy make possible new standards in treatment recommandations based on international guidelines. Developments in radiotherapy irradiation techniques from 2D to 3D-Conformal RT and to IMRT (Intensity Modulated Arc Therapy) make possible to reduce the usual side effects on the organs at risk as: skin, lung, miocard, bone, esophagus and brahial plexus. Dispite of all these progresses acute and late side effects are present. Side effects are as old as the radiotherapy was used. New solutions are available now by improving irradiation techniques. New techniques as sentinel node procedure (SNP) or partial breast irradiation (PBRT) and immediate breast reconstruction with silicon implants (IBRIS) make necessary new considerations regarding the target volume delineations. A new language for definition of gross tumor volume (GTV), clinical target volume (CTV) based on the new diagnostic methods as PET/CT,nonaparticle MRI will have real impact on target delineation and irradiation techniques. "The new common language in breast cancer therapy" would be the first step to improve the endresults and finally the quality of life of the patients. Celsius.

[Target volume margins for lung cancer: internal target volume/clinical target volume].

Science.gov (United States)

Jouin, A; Pourel, N

2013-10-01

The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV-GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned. Copyright © 2013. Published by Elsevier SAS.

Strategies for systemic radiotherapy of micrometastases using antibody-targeted 131I.

Science.gov (United States)

Wheldon, T E; O'Donoghue, J A; Hilditch, T E; Barrett, A

1988-02-01

A simple analysis is developed to evaluate the likely effectiveness of treatment of micrometastases by antibody-targeted 131I. Account is taken of the low levels of tumour uptake of antibody-conjugated 131I presently achievable and of the "energy wastage" in targeting microscopic tumours with a radionuclide whose disintegration energy is widely dissipated. The analysis shows that only modest doses can be delivered to micrometastases when total body dose is restricted to levels which allow recovery of bone marrow. Much higher doses could be delivered to micrometastases when bone marrow rescue is used. A rationale is presented for targeted systemic radiotherapy used in combination with external beam total body irradiation (TBI) and bone marrow rescue. This has some practical advantages. The effect of the targeted component is to impose a biological non-uniformity on the total body dose distribution with regions of high tumour cell density receiving higher doses. Where targeting results in high doses to particular normal organs (e.g. liver, kidney) the total dose to these organs could be kept within tolerable limits by appropriate shielding of the external beam radiation component of the treatment. Greater levels of tumour cell kill should be achievable by the combination regime without any increase in normal tissue damage over that inflicted by conventional TBI. The predicted superiority of the combination regime is especially marked for tumours just below the threshold for detectability (e.g. approximately 1 mm-1 cm diameter). This approach has the advantage that targeted radiotherapy provides only a proportion of the total body dose, most of which is given by a familiar technique. The proportion of dose given by the targeted component could be increased as experience is gained. The predicted superiority of the combination strategy should be experimentally testable using laboratory animals. Clinical applications should be cautiously approached, with due regard to

Nonrandom Intrafraction Target Motions and General Strategy for Correction of Spine Stereotactic Body Radiotherapy

International Nuclear Information System (INIS)

Ma Lijun; Sahgal, Arjun; Hossain, Sabbir; Chuang, Cynthia; Descovich, Martina; Huang, Kim; Gottschalk, Alex; Larson, David A.

2009-01-01

Purpose: To characterize nonrandom intrafraction target motions for spine stereotactic body radiotherapy and to develop a method of correction via image guidance. The dependence of target motions, as well as the effectiveness of the correction strategy for lesions of different locations within the spine, was analyzed. Methods and Materials: Intrafraction target motions for 64 targets in 64 patients treated with a total of 233 fractions were analyzed. Based on the target location, the cases were divided into three groups, i.e., cervical (n = 20 patients), thoracic (n = 20 patients), or lumbar-sacrum (n = 24 patients) lesions. For each case, time-lag autocorrelation analysis was performed for each degree of freedom of motion that included both translations (x, y, and z shifts) and rotations (roll, yaw, and pitch). A general correction strategy based on periodic interventions was derived to determine the time interval required between two adjacent interventions, to overcome the patient-specific target motions. Results: Nonrandom target motions were detected for 100% of cases regardless of target locations. Cervical spine targets were found to possess the highest incidence of nonrandom target motion compared with thoracic and lumbar-sacral lesions (p < 0.001). The average time needed to maintain the target motion to within 1 mm of translation or 1 deg. of rotational deviation was 5.5 min, 5.9 min, and 7.1 min for cervical, thoracic, and lumbar-sacrum locations, respectively (at 95% confidence level). Conclusions: A high incidence of nonrandom intrafraction target motions was found for spine stereotactic body radiotherapy treatments. Periodic interventions at approximately every 5 minutes or less were needed to overcome such motions.

Integration of multidisciplinary technologies for real time target visualization and verification for radiotherapy

Directory of Open Access Journals (Sweden)

Chang WC

2014-06-01

Full Text Available Wen-Chung Chang,1,* Chin-Sheng Chen,2,* Hung-Chi Tai,3 Chia-Yuan Liu,4,5 Yu-Jen Chen3 1Department of Electrical Engineering, National Taipei University of Technology, Taipei, Taiwan; 2Graduate Institute of Automation Technology, National Taipei University of Technology, Taipei, Taiwan; 3Department of Radiation Oncology, Mackay Memorial Hospital, Taipei, Taiwan; 4Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan; 5Department of Medicine, Mackay Medical College, New Taipei City, Taiwan  *These authors contributed equally to this work Abstract: The current practice of radiotherapy examines target coverage solely from digitally reconstructed beam's eye view (BEV in a way that is indirectly accessible and that is not in real time. We aimed to visualize treatment targets in real time from each BEV. The image data of phantom or patients from ultrasound (US and computed tomography (CT scans were captured to perform image registration. We integrated US, CT, US/CT image registration, robotic manipulation of US, a radiation treatment planning system, and a linear accelerator to constitute an innovative target visualization system. The performance of this algorithm segmented the target organ in CT images, transformed and reconstructed US images to match each orientation, and generated image registration in real time mode with acceptable accuracy. This image transformation allowed physicians to visualize the CT image-reconstructed target via a US probe outside the BEV that was non-coplanar to the beam's plane. It allowed the physicians to remotely control the US probe that was equipped on a robotic arm to dynamically trace and real time monitor the coverage of the target within the BEV during a simulated beam-on situation. This target visualization system may provide a direct remotely accessible and real time way to visualize, verify, and ensure tumor targeting during radiotherapy. Keywords: ultrasound, computerized tomography

Development of radiation oncology learning system combined with multi-institutional radiotherapy database (ROGAD)

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Takemura, Akihiro; Iinuma, Masahiro; Kou, Hiroko [Kanazawa Univ. (Japan). School of Medicine; Harauchi, Hajime; Inamura, Kiyonari

1999-09-01

We have constructed and are operating a multi-institutional radiotherapy database ROGAD (Radiation Oncology Greater Area Database) since 1992. One of it's purpose is 'to optimize individual radiotherapy plans'. We developed Radiation oncology learning system combined with ROGAD' which conforms to that purpose. Several medical doctors evaluated our system. According to those evaluations, we are now confident that our system is able to contribute to improvement of radiotherapy results. Our final target is to generate a good cyclic relationship among three components: radiotherapy results according to ''Radiation oncology learning system combined with ROGAD.'; The growth of ROGAD; and radiation oncology learning system. (author)

Target volume definition with 18F-FDG PET-CT in radiotherapy treatment planning

International Nuclear Information System (INIS)

Carson, K. J.; Hanna, G. G.; Hounsell, A. R.

2011-01-01

There is considerable interest in using 18F -Fluorodeoxyglucose (FDG) positron emission tomography (PET) images for radiotherapy treatment planning (RTF) purposes, and in particular for defining target volumes. This is a rapidly evolving subject and this review describes the background to this application of PET imaging and discusses the issues involved. (authors)

Sphere of equivalence--a novel target volume concept for intraoperative radiotherapy using low-energy X rays.

Science.gov (United States)

Herskind, Carsten; Griebel, Jürgen; Kraus-Tiefenbacher, Uta; Wenz, Frederik

2008-12-01

Accelerated partial breast radiotherapy with low-energy photons from a miniature X-ray machine is undergoing a randomized clinical trial (Targeted Intra-operative Radiation Therapy [TARGIT]) in a selected subgroup of patients treated with breast-conserving surgery. The steep radial dose gradient implies reduced tumor cell control with increasing depth in the tumor bed. The purpose was to compare the expected risk of local recurrence in this nonuniform radiation field with that after conventional external beam radiotherapy. The relative biologic effectiveness of low-energy photons was modeled using the linear-quadratic formalism including repair of sublethal lesions during protracted irradiation. Doses of 50-kV X-rays (Intrabeam) were converted to equivalent fractionated doses, EQD2, as function of depth in the tumor bed. The probability of local control was estimated using a logistic dose-response relationship fitted to clinical data from fractionated radiotherapy. The model calculations show that, for a cohort of patients, the increase in local control in the high-dose region near the applicator partly compensates the reduction of local control at greater distances. Thus a "sphere of equivalence" exists within which the risk of recurrence is equal to that after external fractionated radiotherapy. The spatial distribution of recurrences inside this sphere will be different from that after conventional radiotherapy. A novel target volume concept is presented here. The incidence of recurrences arising in the tumor bed around the excised tumor will test the validity of this concept and the efficacy of the treatment. Recurrences elsewhere will have implications for the rationale of TARGIT.

Target position uncertainty during visually guided deep-inspiration breath-hold radiotherapy in locally advanced lung cancer

DEFF Research Database (Denmark)

Rydhog, Jonas Scherman; de Blanck, Steen Riisgaard; Josipovic, Mirjana

2017-01-01

Purpose: The purpose of this study was to estimate the uncertainty in voluntary deep-inspiration breath hold (DISH) radiotherapy for locally advanced non-small cell lung cancer (NSCLC) patients.Methods: Perpendicular fluoroscopic movies were acquired in free breathing (FB) and DIBH during a course...... of visually guided DIBH radiotherapy of nine patients with NSCLC. Patients had liquid markers injected in mediastinal lymph nodes and primary tumours. Excursion, systematic- and random errors, and inter-breath-hold position uncertainty were investigated using an image based tracking algorithm.Results: A mean...... small in visually guided breath-hold radiotherapy of NSCLC. Target motion could be substantially reduced, but not eliminated, using visually guided DIBH. (C) 2017 Elsevier B.V. All rights reserved....

TARGET 2 and Settlement Finality

Directory of Open Access Journals (Sweden)

Ivan MANGATCHEV

2011-03-01

Full Text Available This article examines how TARGET 2 as system implements the idea of settlement finality regulated by Directive 98/26 EC of the European parliament and of the Council of 19 May 1998 on settlement finality in payment and securities settlement systems (Settlement Finality Directive and Directive 2009/44/EC of the European parliament and of the Council of 6 May 2009 amending Directive 98/26/EC on settlement finality in payment and securities settlement systems and Directive 2002/47/EC on financial collateral arrangements as regards linked systems and credit claims (Directive 2009/44/EC. As the title of the arti and finality of the settlement in this system.

Preliminary estimation of minimum target dose in intracavitary radiotherapy for cervical cancer

Energy Technology Data Exchange (ETDEWEB)

Ohara, Kiyoshi; Oishi-Tanaka, Yumiko; Sugahara, Shinji; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

2001-08-01

In intracavitary radiotherapy (ICRT) for cervical cancer, minimum target dose (D{sub min}) will pertain to local disease control more directly than will reference point A dose (D{sub A}). However, ICRT has been performed traditionally without specifying D{sub min} since the target volume was not identified. We have estimated D{sub min} retrospectively by identifying tumors using magnetic resonance (MR) images. Pre- and posttreatment MR images of 31 patients treated with high-dose-rate ICRT were used. ICRT was performed once weekly at 6.0 Gy D{sub A}, and involved 2-5 insertions for each patient, 119 insertions in total. D{sub min} was calculated arbitrarily simply at the point A level using the tumor width (W{sub A}) to compare with D{sub A}. W{sub A} at each insertion was estimated by regression analysis with pre- and posttreatment W{sub A}. D{sub min} for each insertion varied from 3.0 to 46.0 Gy, a 16-fold difference. The ratio of total D{sub min} to total D{sub A} for each patient varied from 0.5 to 6.5. Intrapatient D{sub min} difference between the initial insertion and final insertion varied from 1.1 to 3.4. Preliminary estimation revealed that D{sub min} varies widely under generic dose prescription. Thorough D{sub min} specification will be realized when ICRT-applicator insertion is performed under MR imaging. (author)

Development of a Software for Quantitative Evaluation Radiotherapy Target and Organ-at-Risk Segmentation Comparison

NARCIS (Netherlands)

Kalpathy-Cramer, Jayashree; Awan, Musaddiq; Bedrick, Steven; Rasch, Coen R. N.; Rosenthal, David I.; Fuller, Clifton D.

2014-01-01

Modern radiotherapy requires accurate region of interest (ROI) inputs for plan optimization and delivery. Target delineation, however, remains operator-dependent and potentially serves as a major source of treatment delivery error. In order to optimize this critical, yet observer-driven process, a

Automatic definition of targeted biological volumes for the radiotherapy applications

International Nuclear Information System (INIS)

Hatt, M.; Visvikis, D.; Cheze-Le-Rest, C.; Pradier, O.

2009-01-01

The proposed method: Fuzzy locally adaptive Bayesian (F.L.A.B.) showed its reliability and its precision on very complete collection of realistic simulated and real data. Its use in the context of radiotherapy allows to consider easily the studies implementation and scenari of dose painting or dose escalation, including in complex cases of heterogenous fixations. It is conceivable to apply F.L.A.B. on PET images with F.M.I.S.O. ( 18 F fluoro misonidazole) or F.L.T. (fluoro-L-thymidine) to complete the definition of the biological target volume. (N.C.)

A multimodality segmentation framework for automatic target delineation in head and neck radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Yang, Jinzhong; Aristophanous, Michalis, E-mail: MAristophanous@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Beadle, Beth M.; Garden, Adam S. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Schwartz, David L. [Department of Radiation Oncology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390 (United States)

2015-09-15

Purpose: To develop an automatic segmentation algorithm integrating imaging information from computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) to delineate target volume in head and neck cancer radiotherapy. Methods: Eleven patients with unresectable disease at the tonsil or base of tongue who underwent MRI, CT, and PET/CT within two months before the start of radiotherapy or chemoradiotherapy were recruited for the study. For each patient, PET/CT and T1-weighted contrast MRI scans were first registered to the planning CT using deformable and rigid registration, respectively, to resample the PET and magnetic resonance (MR) images to the planning CT space. A binary mask was manually defined to identify the tumor area. The resampled PET and MR images, the planning CT image, and the binary mask were fed into the automatic segmentation algorithm for target delineation. The algorithm was based on a multichannel Gaussian mixture model and solved using an expectation–maximization algorithm with Markov random fields. To evaluate the algorithm, we compared the multichannel autosegmentation with an autosegmentation method using only PET images. The physician-defined gross tumor volume (GTV) was used as the “ground truth” for quantitative evaluation. Results: The median multichannel segmented GTV of the primary tumor was 15.7 cm{sup 3} (range, 6.6–44.3 cm{sup 3}), while the PET segmented GTV was 10.2 cm{sup 3} (range, 2.8–45.1 cm{sup 3}). The median physician-defined GTV was 22.1 cm{sup 3} (range, 4.2–38.4 cm{sup 3}). The median difference between the multichannel segmented and physician-defined GTVs was −10.7%, not showing a statistically significant difference (p-value = 0.43). However, the median difference between the PET segmented and physician-defined GTVs was −19.2%, showing a statistically significant difference (p-value =0.0037). The median Dice similarity coefficient between the multichannel segmented

A multimodality segmentation framework for automatic target delineation in head and neck radiotherapy.

Science.gov (United States)

Yang, Jinzhong; Beadle, Beth M; Garden, Adam S; Schwartz, David L; Aristophanous, Michalis

2015-09-01

To develop an automatic segmentation algorithm integrating imaging information from computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) to delineate target volume in head and neck cancer radiotherapy. Eleven patients with unresectable disease at the tonsil or base of tongue who underwent MRI, CT, and PET/CT within two months before the start of radiotherapy or chemoradiotherapy were recruited for the study. For each patient, PET/CT and T1-weighted contrast MRI scans were first registered to the planning CT using deformable and rigid registration, respectively, to resample the PET and magnetic resonance (MR) images to the planning CT space. A binary mask was manually defined to identify the tumor area. The resampled PET and MR images, the planning CT image, and the binary mask were fed into the automatic segmentation algorithm for target delineation. The algorithm was based on a multichannel Gaussian mixture model and solved using an expectation-maximization algorithm with Markov random fields. To evaluate the algorithm, we compared the multichannel autosegmentation with an autosegmentation method using only PET images. The physician-defined gross tumor volume (GTV) was used as the "ground truth" for quantitative evaluation. The median multichannel segmented GTV of the primary tumor was 15.7 cm(3) (range, 6.6-44.3 cm(3)), while the PET segmented GTV was 10.2 cm(3) (range, 2.8-45.1 cm(3)). The median physician-defined GTV was 22.1 cm(3) (range, 4.2-38.4 cm(3)). The median difference between the multichannel segmented and physician-defined GTVs was -10.7%, not showing a statistically significant difference (p-value = 0.43). However, the median difference between the PET segmented and physician-defined GTVs was -19.2%, showing a statistically significant difference (p-value =0.0037). The median Dice similarity coefficient between the multichannel segmented and physician-defined GTVs was 0.75 (range, 0.55-0.84), and the

A multimodality segmentation framework for automatic target delineation in head and neck radiotherapy

International Nuclear Information System (INIS)

Yang, Jinzhong; Aristophanous, Michalis; Beadle, Beth M.; Garden, Adam S.; Schwartz, David L.

2015-01-01

Purpose: To develop an automatic segmentation algorithm integrating imaging information from computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) to delineate target volume in head and neck cancer radiotherapy. Methods: Eleven patients with unresectable disease at the tonsil or base of tongue who underwent MRI, CT, and PET/CT within two months before the start of radiotherapy or chemoradiotherapy were recruited for the study. For each patient, PET/CT and T1-weighted contrast MRI scans were first registered to the planning CT using deformable and rigid registration, respectively, to resample the PET and magnetic resonance (MR) images to the planning CT space. A binary mask was manually defined to identify the tumor area. The resampled PET and MR images, the planning CT image, and the binary mask were fed into the automatic segmentation algorithm for target delineation. The algorithm was based on a multichannel Gaussian mixture model and solved using an expectation–maximization algorithm with Markov random fields. To evaluate the algorithm, we compared the multichannel autosegmentation with an autosegmentation method using only PET images. The physician-defined gross tumor volume (GTV) was used as the “ground truth” for quantitative evaluation. Results: The median multichannel segmented GTV of the primary tumor was 15.7 cm"3 (range, 6.6–44.3 cm"3), while the PET segmented GTV was 10.2 cm"3 (range, 2.8–45.1 cm"3). The median physician-defined GTV was 22.1 cm"3 (range, 4.2–38.4 cm"3). The median difference between the multichannel segmented and physician-defined GTVs was −10.7%, not showing a statistically significant difference (p-value = 0.43). However, the median difference between the PET segmented and physician-defined GTVs was −19.2%, showing a statistically significant difference (p-value =0.0037). The median Dice similarity coefficient between the multichannel segmented and physician-defined GTVs was

Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

Directory of Open Access Journals (Sweden)

Korevaar Erik W

2008-01-01

Full Text Available Abstract Background The shift from conventional two-dimensional (2D to three-dimensional (3D-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT-based breast and boost planning target volumes (PTV, absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Methods Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. Results With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. Conclusion The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on

Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

International Nuclear Information System (INIS)

Laan, Hans Paul van der; Dolsma, Wil V; Maduro, John H; Korevaar, Erik W; Langendijk, Johannes A

2008-01-01

The shift from conventional two-dimensional (2D) to three-dimensional (3D)-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT)-based breast and boost planning target volumes (PTV), absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on clinical data confirming tumour control probability and normal

Small animal radiotherapy research platforms

Energy Technology Data Exchange (ETDEWEB)

Verhaegen, Frank; Granton, Patrick [Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Tryggestad, Erik, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21231 (United States)

2011-06-21

Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

Small animal radiotherapy research platforms

Science.gov (United States)

Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

2011-06-01

Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research.

Small animal radiotherapy research platforms

International Nuclear Information System (INIS)

Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

2011-01-01

Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

Breathing adapted radiotherapy: final clinic results of the program for the support to costly innovating techniques (Stic) of 2003

International Nuclear Information System (INIS)

Giraud, P.; Giraud, P.; Morvan, E.; Djadi-Prat, J.; Rosenwald, J.C.; Carrere, M.O.

2010-01-01

The authors report the comparison, from a clinic point of view, between breathing adapted conformational radiotherapy (BART) and conventional conformational radiotherapy, in the case of lung and breast cancers. The assessment comprised a clinic examination, a thoracic radiography, breathing functional tests, a thoracic scanography at different moments (3, 6, 12, 18 and 24 months), and dosimetric criteria for tumour target volumes and the different thoracic organs at risk. Data have been collected among more than six hundred patients. Breathing adapted techniques allow acute and late toxicity to be reduced, notably for the lung, heart and oesophagus during a lung irradiation. They are less interesting for mammary irradiation, but could be important for a radiotherapy of the left breast. Short communication

Intercomparison of Dosimeters for Non-Target Organ Dose Measurements in Radiotherapy - Activity of EURADOS WG 9: Radiation Protection in Medicine

International Nuclear Information System (INIS)

Miljanic, S.; Knezevic, Z.; Bessieres, I.; Bordy, J.-M.; D'Agostino, E.; d'Errico, F.; di Fulvio, A.; Domingo, C.; Olko, P.; Stolarczyk; Silari, M.; Harrison, R.

2011-01-01

It has been known for a long time that patients treated with ionizing radiation carry a risk of developing radiation induced cancer in their lifetimes. It is recognized that cure/survival rates in radiotherapy are increasing, but so are secondary cancers. These occurrences are amplified by the early detection of disease in younger patients. These patients are cured from the primary disease and have long life-expectancies, which increase their chances of developing secondary malignancies. The motivation of the EURADOS Working Group 9 (WG 9) ''Radiation protection dosimetry in medicine'' is to assess undue non-target patient doses in radiotherapy and the related risks of secondary malignancy with the most accredited available methods and with the emphasis on a thorough evaluation of dosimetry methods for the measurements of doses remote from the target volume, in phantom experiments. The development of a unified and comprehensive dosimetry methodology for non-target dose estimation is the key element of the WG9 current work. The first scientific aim is to select and review dosimeters suitable for photon and neutron dosimetry in radiotherapy and to evaluate the characteristics of dosimeters at CEA LIST Saclay in reference clinical LINAC beam. (author)

Image-Guided Radiotherapy via Daily Online Cone-Beam CT Substantially Reduces Margin Requirements for Stereotactic Lung Radiotherapy

International Nuclear Information System (INIS)

Grills, Inga S.; Hugo, Geoffrey; Kestin, Larry L.; Galerani, Ana Paula; Chao, K. Kenneth; Wloch, Jennifer; Yan Di

2008-01-01

Purpose: To determine treatment accuracy and margins for stereotactic lung radiotherapy with and without cone-beam CT (CBCT) image guidance. Methods and Materials: Acquired for the study were 308 CBCT of 24 patients with solitary peripheral lung tumors treated with stereotactic radiotherapy. Patients were immobilized in a stereotactic body frame (SBF) or alpha-cradle and treated with image guidance using daily CBCT. Four (T1) or five (T2/metastatic) 12-Gy fractions were prescribed to the planning target volume (PTV) edge. The PTV margin was ≥5 mm depending on a pretreatment estimate of tumor excursion. Initial daily setup was according to SBF coordinates or tattoos for alpha-cradle cases. A CBCT was performed and registered to the planning CT using soft tissue registration of the target. The initial setup error/precorrection position, was recorded for the superior-inferior, anterior-posterior, and medial-lateral directions. The couch was adjusted to correct the tumor positional error. A second CBCT verified tumor position after correction. Patients were treated in the corrected position after the residual errors were ≤2 mm. A final CBCT after treatment assessed intrafraction tumor displacement. Results: The precorrection systematic (Σ) and random errors (σ) for the population ranged from 2-3 mm for SBF and 2-6 mm for alpha-cradle patients; postcorrection errors ranged from 0.4-1.0 mm. Calculated population margins were 9 to 13 mm (SBF) and 10-14 mm (cradle) precorrection, 1-2 mm (SBF), and 2-3 mm (cradle) postcorrection, and 2-4 mm (SBF) and 2-5 mm (cradle) posttreatment. Conclusions: Setup for stereotactic lung radiotherapy using a SBF or alpha-cradle alone is suboptimal. CBCT image guidance significantly improves target positioning and substantially reduces required target margins and normal tissue irradiation

Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy

International Nuclear Information System (INIS)

Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

2016-01-01

To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1–2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85–6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins.

Gold markers for tumor localization and target volume delineation in radiotherapy for rectal cancer

International Nuclear Information System (INIS)

Vorwerk, Hilke; Christiansen, Hans; Hess, Clemens Friedrich; Hermann, Robert Michael; Liersch, Thorsten; Ghadimi, Michael; Rothe, Hilka

2009-01-01

In locally advanced rectal cancer, neoadjuvant radiochemotherapy is indicated. To improve target volume definition for radiotherapy planning, the potential of implanted gold markers in the tumor region was evaluated. In nine consecutive patients, two to three gold markers were implanted in the tumor region during rigid rectoscopy. Computed tomography scans were performed during treatment planning. All electronic portal imaging devices (EPIDs) recorded during treatment series were analyzed. All patients underwent complete tumor resection with meticulous histopathologic examination. The gold markers could easily be implanted into the mesorectal tissue at the caudal tumor border without any complications. They were helpful in identifying the inferior border of the planning target volume in order to spare normal tissue (in particular anal structures). No significant shift of the markers was found during the course of therapy. Marker matching of the EPIDs did not improve patient positioning in comparison to bone structure matching. The former position of at least one marker could be identified in all patients during histopathologic examination. The use of gold marker enables a more precise definition of the target volume for radiotherapy in patients with rectal cancer. This could eventually allow a better protection of anal structures of patients with a tumor localization = 5 cm cranial of the anal sphincter. The implantation of the gold markers improved communication between the surgeon, the radiooncologist and the pathologist resulting in intensified exchange of relevant informations. (orig.)

Clinical variability of target volume description and treatment plans in conformal radiotherapy in muscle invasive bladder cancer

International Nuclear Information System (INIS)

Logue, John P; Sharrock, Carole L; Cowan, Richard A.; Read, Graham; Marrs, Julie; Mott, David

1996-01-01

Purpose/Objective: The delineation of tumor and the production of a treatment plan to encompass this is the prime step in radiotherapy planning. Conformal radiotherapy is developing rapidly and although plentiful research has addressed the implementation of the radiotherapy prescription, scant attention has been made to the fundamental step of production, by the clinician, of an appropriate target volume. As part of an ongoing randomized trial of conformal radiotherapy, in bladder cancer, we have therefore assessed the interphysician variability of radiologists and radiation oncologists (RO) in assessing Gross Tumor Volume(GTV) (ICRU 50) and the adherence of the radiation oncologists to the study protocol of producing a Planning Target Volume (PTV). Materials and Methods: Four patients with T3 carcinoma of bladder who had been entered into the trial were identified. The clinical details, MR scans and CT scans were made available. Eight RO and 3 dedicated diagnostic oncology radiologists were invited to directly outline the GTV onto CT images on a planning computer consul. The RO in addition created a PTV following the trial protocol of 15mm margin around the GTV. Three RO sub-specialized in Urological radiotherapy; all RO had completed training. Volumes were produced, for each clinician, and comparison of these volumes and their isocenters were analyzed. In addition the margins allowed were measured and compared. Results: There was a maximum variation ratio (largest to smallest volume outlined) of the GTV in the four cases of 1.74 among radiologists and 3.74 among oncologists. There was a significant difference (p=0.01) in mean GTV between RO and the radiologists. The mean GTV of the RO exceeded the radiologists by a factor of 1.29 with a mean difference of 13.4 cm 3 The between observer variance within speciality comprised only 9.9% of the total variance in the data having accounted for case and observers speciality. The variation ratio in PTV among oncologists

Impact of target reproducibility on tumor dose in stereotactic radiotherapy of targets in the lung and liver.

Science.gov (United States)

Wulf, Jörn; Hädinger, Ulrich; Oppitz, Ulrich; Thiele, Wibke; Flentje, Michael

2003-02-01

Previous analyses of target reproducibility in extracranial stereotactic radiotherapy have revealed standard security margins for planning target volume (PTV) definition of 5mm in axial and 5-10mm in longitudinal direction. In this study the reproducibility of the clinical target volume (CTV) of lung and liver tumors within the PTV over the complete course of hypofractionated treatment is evaluated. The impact of target mobility on dose to the CTV is assessed by dose-volume histograms (DVH). Twenty-two pulmonary and 21 hepatic targets were treated with three stereotactic fractions of 10 Gy to the PTV-enclosing 100%-isodose with normalization to 150% at the isocenter. A conformal dose distribution was related to the PTV, which was defined by margins of 5-10mm added to the CTV. Prior to each fraction a computed tomography (CT)-simulation over the complete target volume was performed resulting in a total of 60 CT-simulations for lung and 58 CT-simulations for hepatic targets. The CTV from each CT-simulation was segmented and matched with the CT-study used for treatment planning. A DVH of the simulated CTV was calculated for each fraction. The target coverage (TC) of dose to the simulated CTV was defined as the proportion of the CTV receiving at least the reference dose (100%). A decrease of TC to or=95% at each fraction of treatment. Pulmonary targets with increased breathing mobility and liver tumors >100 cm(3) are at risk for target deviation exceeding the standard security margins for PTV-definition at least for one fraction and require individual evaluation of sufficient margins.

Nanoparticle-guided radiotherapy

DEFF Research Database (Denmark)

2012-01-01

The present invention relates to a method and nano-sized particles for image guided radiotherapy (IGRT) of a target tissue. More specifically, the invention relates to nano-sized particles comprising X-ray-imaging contrast agents in solid form with the ability to block x-rays, allowing for simult...... for simultaneous or integrated external beam radiotherapy and imaging, e.g., using computed tomography (CT)....

Impact of target reproducibility on tumor dose in stereotactic radiotherapy of targets in the lung and liver

International Nuclear Information System (INIS)

Wulf, Joern; Haedinger, Ulrich; Oppitz, Ulrich; Thiele, Wibke; Flentje, Michael

2003-01-01

Background and purpose: Previous analyses of target reproducibility in extracranial stereotactic radiotherapy have revealed standard security margins for planning target volume (PTV) definition of 5 mm in axial and 5-10 mm in longitudinal direction. In this study the reproducibility of the clinical target volume (CTV) of lung and liver tumors within the PTV over the complete course of hypofractionated treatment is evaluated. The impact of target mobility on dose to the CTV is assessed by dose-volume histograms (DVH). Materials and methods: Twenty-two pulmonary and 21 hepatic targets were treated with three stereotactic fractions of 10 Gy to the PTV-enclosing 100%-isodose with normalization to 150% at the isocenter. A conformal dose distribution was related to the PTV, which was defined by margins of 5-10 mm added to the CTV. Prior to each fraction a computed tomography (CT)-simulation over the complete target volume was performed resulting in a total of 60 CT-simulations for lung and 58 CT-simulations for hepatic targets. The CTV from each CT-simulation was segmented and matched with the CT-study used for treatment planning. A DVH of the simulated CTV was calculated for each fraction. The target coverage (TC) of dose to the simulated CTV was defined as the proportion of the CTV receiving at least the reference dose (100%). Results: A decrease of TC to 3 . Conclusions: Target reproducibility was precise within the reference isodose in 91% of lung and 81% of liver tumors with a TC of the complete CTV ≥95% at each fraction of treatment. Pulmonary targets with increased breathing mobility and liver tumors >100 cm 3 are at risk for target deviation exceeding the standard security margins for PTV-definition at least for one fraction and require individual evaluation of sufficient margins

Combined-modality treatment of solid tumors using radiotherapy and molecular targeted agents.

Science.gov (United States)

Ma, Brigette B Y; Bristow, Robert G; Kim, John; Siu, Lillian L

2003-07-15

Molecular targeted agents have been combined with radiotherapy (RT) in recent clinical trials in an effort to optimize the therapeutic index of RT. The appeal of this strategy lies in their potential target specificity and clinically acceptable toxicity. This article integrates the salient, published research findings into the underlying molecular mechanisms, preclinical efficacy, and clinical applicability of combining RT with molecular targeted agents. These agents include inhibitors of intracellular signal transduction molecules, modulators of apoptosis, inhibitors of cell cycle checkpoints control, antiangiogenic agents, and cyclo-oxygenase-2 inhibitors. Molecular targeted agents can have direct effects on the cytoprotective and cytotoxic pathways implicated in the cellular response to ionizing radiation (IR). These pathways involve cellular proliferation, DNA repair, cell cycle progression, nuclear transcription, tumor angiogenesis, and prostanoid-associated inflammation. These pathways can also converge to alter RT-induced apoptosis, terminal growth arrest, and reproductive cell death. Pharmacologic modulation of these pathways may potentially enhance tumor response to RT though inhibition of tumor repopulation, improvement of tumor oxygenation, redistribution during the cell cycle, and alteration of intrinsic tumor radiosensitivity. Combining RT and molecular targeted agents is a rational approach in the treatment of solid tumors. Translation of this approach from promising preclinical data to clinical trials is actively underway.

Rule of lymph node metastasis and proper target of postoperative radiotherapy for thoracic esophageal carcinoma

International Nuclear Information System (INIS)

Xiao Zefen; Zhou Zongmei; Lv Jima; Liang Jun; Ou Guangfei; Jin Jing; Song Yongwen; Zhang Shiping; Yin Weibo

2008-01-01

Objective: To analyze the rule of lymph node metastasis in thoracic esophageal carcinoma, and to study the proper radiation target. Methods: From September 1986 to December 1997,549 patients with esophageal carcinoma who had undergone radical resection were divided into surgery alone group (S,275 patients) or surgery plus radiotherapy group(S + R,274 patients). Radiotherapy was begun 3 to 4 weeks after operation. The radiation target included both supra-clavicular areas and the entire mediastinum. The total dose was 50 Gy in 25 fractions over 5 weeks for the supra-clavicular areas and 60 Gy in 30 fractions over 6 weeks for the entire mediastinum. Results: The 5-year overall survival of patients with lymph node metastasis in one anatomic site and two anatomic sites was 31.5% and 13.9% (P=0.013), respectively. For patients with > 2 positive nodes metastasis receiving surgery alone, the corresponding 5-year survival was 24.8% and 4.9% (P=0.046), respectively. The median number of dissected lymph nodes of the upper-, middle-and lower-segment esophageal carcinoma was 13, 17 and 20, respectively. The rate of metastatic lymph node in the para-esophagus region was the highest(61.5%-64.9%), which was not different among the different primary sites (P=0.922). The anastomotic stoma recurrence rate of the upper-segment esophageal carcinoma was higher than that of the middle- or lower-segment carcinomas (16.7%, 3.1%, and 7.7%, χ 2 =9.02,P<0.05). Conclusions: For the thoracic esophageal carcinoma, the number of anatomic sites of lymph node metastasis is an important factor affecting the survival. The lower rate of lymph node metastasis of the upper segment esophageal carcinoma may be corrected with the less lymph node dissected. The rate of lymph node metastasis in para-esophageal region is not related with the lesion segment. The anastomotic stoma is an important radiotherapy target for upper segment esophageal carcinoma. (authors)

Intensity-Modulated Radiotherapy for Craniospinal Irradiation: Target Volume Considerations, Dose Constraints, and Competing Risks

International Nuclear Information System (INIS)

Parker, William; Filion, Edith; Roberge, David; Freeman, Carolyn R.

2007-01-01

Purpose: To report the results of an analysis of dose received to tissues and organs outside the target volume, in the setting of spinal axis irradiation for the treatment of medulloblastoma, using three treatment techniques. Methods and Materials: Treatment plans (total dose, 23.4 Gy) for a standard two-dimensional (2D) technique, a three-dimensional (3D) technique using a 3D imaging-based target volume, and an intensity-modulated radiotherapy (IMRT) technique, were compared for 3 patients in terms of dose-volume statistics for target coverage, as well as organ at risk (OAR) and overall tissue sparing. Results: Planning target volume coverage and dose homogeneity was superior for the IMRT plans for V 95% (IMRT, 100%; 3D, 96%; 2D, 98%) and V 107% (IMRT, 3%; 3D, 38%; 2D, 37%). In terms of OAR sparing, the IMRT plan was better for all organs and whole-body contour when comparing V 10Gy , V 15Gy , and V 20Gy . The 3D plan was superior for V 5Gy and below. For the heart and liver in particular, the IMRT plans provided considerable sparing in terms of V 10Gy and above. In terms of the integral dose, the IMRT plans were superior for liver (IMRT, 21.9 J; 3D, 28.6 J; 2D, 38.6 J) and heart (IMRT, 9 J; 3D, 14.1J; 2D, 19.4 J), the 3D plan for the body contour (IMRT, 349 J; 3D, 337 J; 2D, 555 J). Conclusions: Intensity-modulated radiotherapy is a valid treatment option for spinal axis irradiation. We have shown that IMRT results in sparing of organs at risk without a significant increase in integral dose

PET/CT Based Dose Planning in Radiotherapy

DEFF Research Database (Denmark)

Berthelsen, Anne Kiil; Jakobsen, Annika Loft; Sapru, Wendy

2011-01-01

radiotherapy planning with PET/CT prior to the treatment. The PET/CT, including the radiotherapy planning process as well as the radiotherapy process, is outlined in detail. The demanding collaboration between mould technicians, nuclear medicine physicians and technologists, radiologists and radiology......This mini-review describes how to perform PET/CT based radiotherapy dose planning and the advantages and possibilities obtained with the technique for radiation therapy. Our own experience since 2002 is briefly summarized from more than 2,500 patients with various malignant diseases undergoing...... technologists, radiation oncologists, physicists, and dosimetrists is emphasized. We strongly believe that PET/CT based radiotherapy planning will improve the therapeutic output in terms of target definition and non-target avoidance and will play an important role in future therapeutic interventions in many...

Megavoltage conebeam CT cine as final verification of treatment plan in lung stereotactic body radiotherapy.

Science.gov (United States)

Kudithipudi, Vijay; Gayou, Olivier; Colonias, Athanasios

2016-06-01

To analyse the clinical impact of megavoltage conebeam computed tomography (MV-CBCT) cine on internal target volume (ITV) coverage in lung stereotactic body radiotherapy (SBRT). One hundred and six patients received lung SBRT. All underwent 4D computed tomography simulation followed by treatment via image guided 3D conformal or intensity modulated radiation. Prior to SBRT, all patients underwent MV-CBCT cine, in which raw projections are displayed as beam's-eye-view fluoroscopic series with the planning target volume (PTV) projected onto each image, enabling verification of tumour motion relative to the PTV and assessment of adequacy of treatment margin. Megavoltage conebeam computed tomography cine was completed 1-2 days prior to SBRT. Four patients (3.8%) had insufficient ITV coverage inferiorly at cine review. All four plans were changed by adding 5 mm on the PTV margin inferiorly. The mean change in PTV volumes was 3.9 cubic centimetres (cc) (range 1.85-6.32 cc). Repeat cine was performed after plan modification to ensure adequate PTV coverage in the modified plans. PTV margin was adequate in the majority of patients with this technique. MV-CBCT cine did show insufficient coverage in a small subset of patients. Insufficient PTV margins may be a function of 4D CT simulation inadequacies or deficiencies in visualizing the ITV inferior border in the full-inhale phase. MV-CBCT cine is a valuable tool for final verification of PTV margins. © 2016 The Royal Australian and New Zealand College of Radiologists.

Molecular targeting of gene therapy and radiotherapy

International Nuclear Information System (INIS)

Weichselbaum, R.R.; Kufe, D.W.; Advani, S.J.; Roizman, B.

2001-01-01

The full promise of gene therapy has been limited by the lack of specificity of vectors for tumor tissue as well as the lack of antitumor efficacy of transgenes encoded by gene delivery systems. In this paper we review our studies investigating two modifications of gene therapy combined with radiotherapy. The first investigations described include studies of radiation inducible gene therapy. In this paradigm, radio-inducible DNA sequences from the CarG elements of the Egr-1 promoter are cloned upstream of a cDNA encoding TNFa. The therapeutic gene (TNFa) is induced by radiation within the tumor microenvironment. In the second paradigm, genetically engineered herpes simplex virus (HSV-1) is induced by ionizing radiation to proliferate within the tumor volume. These modifications of radiotherapy and gene therapy may enhance the efficacy of both treatments

Planning magnetic resonance imaging for prostate cancer intensity-modulated radiation therapy: Impact on target volumes, radiotherapy dose and androgen deprivation administration.

Science.gov (United States)

Horsley, Patrick J; Aherne, Noel J; Edwards, Grace V; Benjamin, Linus C; Wilcox, Shea W; McLachlan, Craig S; Assareh, Hassan; Welshman, Richard; McKay, Michael J; Shakespeare, Thomas P

2015-03-01

Magnetic resonance imaging (MRI) scans are increasingly utilized for radiotherapy planning to contour the primary tumors of patients undergoing intensity-modulated radiation therapy (IMRT). These scans may also demonstrate cancer extent and may affect the treatment plan. We assessed the impact of planning MRI detection of extracapsular extension, seminal vesicle invasion, or adjacent organ invasion on the staging, target volume delineation, doses, and hormonal therapy of patients with prostate cancer undergoing IMRT. The records of 509 consecutive patients with planning MRI scans being treated with IMRT for prostate cancer between January 2010 and July 2012 were retrospectively reviewed. Tumor staging and treatment plans before and after MRI were compared. Of the 509 patients, 103 (20%) were upstaged and 44 (9%) were migrated to a higher risk category as a result of findings at MRI. In 94 of 509 patients (18%), the MRI findings altered management. Ninety-four of 509 patients (18%) had a change to their clinical target volume (CTV) or treatment technique, and in 41 of 509 patients (8%) the duration of hormone therapy was changed because of MRI findings. The use of radiotherapy planning MRI altered CTV design, dose and/or duration of androgen deprivation in 18% of patients in this large, single institution series of men planned for dose-escalated prostate IMRT. This has substantial implications for radiotherapy target volumes and doses, as well as duration of androgen deprivation. Further research is required to investigate whether newer MRI techniques can simultaneously fulfill staging and radiotherapy contouring roles. © 2014 Wiley Publishing Asia Pty Ltd.

Hypoxia targeted bifunctional suicide gene expression enhances radiotherapy in vitro and in vivo

International Nuclear Information System (INIS)

Sun, Xiaorong; Xing, Ligang; Deng, Xuelong; Hsiao, Hung Tsung; Manami, Akiko; Koutcher, Jason A.; Clifton Ling, C.; Li, Gloria C.

2012-01-01

Purpose: To investigate whether hypoxia targeted bifunctional suicide gene expression-cytosine deaminase (CD) and uracil phosphoribosyltransferase (UPRT) with 5-FC treatments can enhance radiotherapy. Materials and methods: Stable transfectants of R3327-AT cells were established which express a triple-fusion-gene: CD, UPRT and monomoric DsRed (mDsRed) controlled by a hypoxia inducible promoter. Hypoxia-induced expression/function of CDUPRTmDsRed was verified by western blot, flow cytometry, fluorescent microscopy, and cytotoxicity assay of 5-FU and 5-FC. Tumor-bearing mice were treated with 5-FC and local radiation. Tumor volume was monitored and compared with those treated with 5-FC or radiation alone. In addition, the CDUPRTmDsRed distribution in hypoxic regions of tumor sections was visualized with fluorescent microscopy. Results: Hypoxic induction of CDUPRTmDsRed protein correlated with increased sensitivity to 5-FC and 5-FU. Significant radiosensitization effects were detected after 5-FC treatments under hypoxic conditions. In the tumor xenografts, the distribution of CDUPRTmDsRed expression visualized with fluorescence microscopy was co-localized with the hypoxia marker pimonidazole positive staining cells. Furthermore, administration of 5-FC to mice in combination with local irradiation resulted in significant tumor regression, as in comparison with 5-FC or radiation treatments alone. Conclusions: Our data suggest that the hypoxia-inducible CDUPRT/5-FC gene therapy strategy has the ability to specifically target hypoxic cancer cells and significantly improve the tumor control in combination with radiotherapy.

The target volume concept at the recording of external beam radiotherapy

International Nuclear Information System (INIS)

Quast, U.; Glaeser, L.

1981-01-01

With the aim of complete, exact and reproducible manual recording and documentation of external beam radiotherapy a concept is proposed providing treatment planning and recording related to space and time for target volumes of different order corresponding to Ist, IInd or IIIrd part of treatment course, regarding all dose limiting organs at risk. The record consists of the dosage plan for medical treatment planning, the treatment plan for physical dose distribution planning and the treatment record of absorbed doses delivered as well as a checklist for patient and machine set-up, and labels for intended actions during treatment development. A clear arrangement of the record form in logical order was found, demanding exact specification of target(s) and beam(s) and their relation in space and time; asking for verbal and graphical description of target volumes, organs at risk, patient positioning, beam portals and dose reference points in terms of patients' anatomy; emphasizing the most important medical data by marked areas and leaving enough empty space for additional data, remarks or comments. During several years of clinical use these record forms proved to be suitable for all cases of external beam therapy, for complex situations of target volumes and treatment-scheduling, for all treatment techniques and radiation qualities and for all ways of physical treatment planning. They can be extended to automatic treatment verification, monitoring and recording as well as to the application of in-vivo-measurements of absorbed doses. (orig.) [de

Radiotherapy for Brain Metastases From Renal Cell Carcinoma in the Targeted Therapy Era: The University of Rochester Experience.

Science.gov (United States)

Bates, James E; Youn, Paul; Peterson, Carl R; Usuki, Kenneth Y; Walter, Kevin A; Okunieff, Paul; Milano, Michael T

2017-10-01

Radiotherapy remains the standard approach for brain metastases from renal cell carcinoma (RCC). Kinase inhibitors (KI) have become standard of care for metastatic RCC. They also increase the radiosensitivity of various tumor types in preclinical models. Data are lacking regarding the effect of KIs among RCC patients undergoing radiotherapy for brain metastases. We report our experience of radiotherapy for brain metastatic RCC in the era of targeted therapy and analyzed effects of concurrent KI therapy. We retrospectively analyzed 25 consecutive patients who received radiotherapy for brain metastases from RCC with whole-brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), or both. Kaplan-Meier rates of overall survival (OS) and brain progression-free survival (BPFS) were calculated and univariate analyses performed. Lower diagnosis-specific graded prognostic assessment (DS-GPA) score and multiple intracranial metastases were associated with decreased OS and BPFS on univariate analysis; DS-GPA is also a prognostic factor on multivariate analysis. There was no significant difference in OS or BPFS for SRS compared with WBRT or WBRT and SRS combined. The concurrent use of KI was not associated with any change in OS or BPFS. This hypothesis-generating analysis suggests among patients with brain metastatic RCC treated with the most current therapies, those selected to undergo SRS did not experience significantly different survival or control outcomes than those selected to undergo WBRT. From our experience to date, limited in patient numbers, there seems to be neither harm nor benefit in using concurrent KI therapy during radiotherapy. Given that most patients progress systemically, we would recommend considering KI use during brain radiotherapy in these patients.

Optimization of radiotherapy to target volumes with concave outlines: target-dose homogenization and selective sparing of critical structures by constrained matrix inversion

Energy Technology Data Exchange (ETDEWEB)

Colle, C; Van den Berge, D; De Wagter, C; Fortan, L; Van Duyse, B; De Neve, W

1995-12-01

The design of 3D-conformal dose distributions for targets with concave outlines is a technical challenge in conformal radiotherapy. For these targets, it is impossible to find beam incidences for which the target volume can be isolated from the tissues at risk. Commonly occurring examples are most thyroid cancers and the targets located at the lower neck and upper mediastinal levels related to some head and neck. A solution to this problem was developed, using beam intensity modulation executed with a multileaf collimator by applying a static beam-segmentation technique. The method includes the definition of beam incidences and beam segments of specific shape as well as the calculation of segment weights. Tests on Sherouse`s GRATISTM planning system allowed to escalate the dose to these targets to 65-70 Gy without exceeding spinal cord tolerance. Further optimization by constrained matrix inversion was investigated to explore the possibility of further dose escalation.

Can FDG-PET assist in radiotherapy target volume definition of metastatic lymph nodes in head-and-neck cancer?

NARCIS (Netherlands)

Schinagl, D.A.X.; Hoffmann, A.L.; Vogel, W.V.; Dalen, J.A. van; Verstappen, S.M.M.; Oyen, W.J.G.; Kaanders, J.H.A.M.

2009-01-01

BACKGROUND AND PURPOSE: The role of FDG-PET in radiotherapy target volume definition of the neck was evaluated by comparing eight methods of FDG-PET segmentation to the current CT-based practice of lymph node assessment in head-and-neck cancer patients. MATERIALS AND METHODS: Seventy-eight

Recurrence pattern of squamous cell carcinoma in the midthoracic esophagus: implications for the clinical target volume design of postoperative radiotherapy

Directory of Open Access Journals (Sweden)

Wang X

2016-10-01

Full Text Available Xiaoli Wang,1,2,* Yijun Luo,1,2,* Minghuan Li,2 Hongjiang Yan,2 Mingping Sun,2 Tingyong Fan2 1School of Medicine and Life Sciences, Jinan University-Shandong Academy of Medical Sciences, Jinan, Shandong, People’s Republic of China; 2Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong, People’s Republic of China *These authors contributed equally to this work Background: Postoperative radiotherapy has shown positive efficacy in lowering the recurrence rate and improving the survival rate for patients with esophageal squamous cell carcinoma (ESCC. However, controversies still exist about the postoperative prophylactic radiation target volume. This study was designed to analyze the patterns of recurrence and to provide a reference for determination of the postoperative radiotherapy target volume for patients with midthoracic ESCC.Patients and methods: A total of 338 patients with recurrent or metastatic midthoracic ESCC after radical surgery were retrospectively examined. The patterns of recurrence including locoregional and distant metastasis were analyzed for these patients.Results: The rates of lymph node (LN metastasis were 28.4% supraclavicular, 77.2% upper mediastinal, 32.0% middle mediastinal, 50.0% lower mediastinal, and 19.5% abdominal LNs. In subgroup analyses, the rate of abdominal LN metastasis was significantly higher in patients with histological node-positive than that in patients with histological node-negative (P=0.033. Further analysis in patients with histological node-positive demonstrated that patients with three or more positive nodes are more prone to abdominal LN metastasis, compared with patients with one or two positive nodes (χ2=4.367, P=0.037. The length of tumor and histological differentiation were also the high-risk factors for abdominal LN metastasis.Conclusion: For midthoracic ESCC with histological node-negative, or one or two positive nodes, the supraclavicular and

The Role of Seminal Vesicle Motion in Target Margin Assessment for Online Image-Guided Radiotherapy for Prostate Cancer

International Nuclear Information System (INIS)

Liang Jian; Wu Qiuwen; Yan Di

2009-01-01

Purpose: For patients with intermediate- and high-risk prostate cancer, the seminal vesicles (SVs) are included in the clinical target volume (CTV). The purposes of this study are to investigate interfraction motion characteristics of the SVs and determine proper margins for online computed tomography image guidance. Methods and Materials: Twenty-four patients, each with 16 daily helical computed tomography scans, were included in this study. A binary image mask was used for image registration to determine daily organ motion. Two online image-guided radiotherapy strategies (prostate only and prostate + SVs) were simulated in a hypofractionated scheme. Three margin designs were studied for both three-dimensional conformal radiotherapy and intensity-modulated radiotherapy (IMRT). In prostate-only guidance, Margin A was uniformly applied to the whole CTV, and Margin B was applied to the SVs with a fixed 3-mm prostate margin. In prostate plus SV guidance, Margin C was uniformly applied to the CTV. The minimum margins were sought to satisfy the criterion that minimum cumulative CTV dose be more than those of the planning target volume in the plan for greater than 95% of patients. Results: The prostate and SVs move significantly more in the anterior-posterior and superior-inferior than right-left directions. The anterior-posterior motion of the prostate and SVs correlated (R 2 = 0.7). The SVs move significantly more than the prostate. The minimum margins found were 2.5 mm for three-dimensional conformal radiotherapy and 4.5, 4.5, and 3.0 mm for Margins A, B, and C for IMRT, respectively. Margins for IMRT were larger, but the irradiated volume and doses to critical structures were smaller. Minimum margins of 4.5 mm to the SVs and 3 mm to the prostate are recommended for IMRT with prostate-only guidance. Conclusions: The SVs move independently from the prostate gland, and additional margins are necessary for image-guided radiotherapy

FDG-PET/CT Imaging for Staging and Target Volume Delineation in Preoperative Conformal Radiotherapy of Rectal Cancer

International Nuclear Information System (INIS)

Bassi, Maria Chiara; Turri, Lucia; Sacchetti, Gianmauro; Loi, Gianfranco; Cannillo, Barbara; La Mattina, Pierdaniele; Brambilla, Marco; Inglese, Eugenio; Krengli, Marco

2008-01-01

Purpose: To investigate the potential impact of using 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) on staging and target volume delineation for patients affected by rectal cancer and candidates for preoperative conformal radiotherapy. Methods and Materials: Twenty-five patients diagnosed with rectal cancer T3-4 N0-1 M0-1 and candidates for preoperative radiotherapy underwent PET/CT simulation after injection of 5.18 MBq/kg of FDG. Clinical stage was reassessed on the basis of FDG-PET/CT findings. The gross tumor volume (GTV) and the clinical target volume (CTV) were delineated first on CT and then on PET/CT images. The PET/CT-GTV and PET/CT-CTV were analyzed and compared with CT-GTV and CT-CTV, respectively. Results: In 4 of 25 cases (24%), PET/CT affected tumor staging or the treatment purpose. In 3 of 25 cases (12%) staged N0 M0, PET/CT showed FDG uptake in regional lymph nodes and in a case also in the liver. In a patient with a single liver metastasis PET/CT detected multiple lesions, changing the treatment intent from curative to palliative. The PET/CT-GTV and PET/CT-CTV were significantly greater than the CT-GTV (p = 0.00013) and CT-CTV (p = 0.00002), respectively. The mean difference between PET/CT-GTV and CT-GTV was 25.4% and between PET/CT-CTV and CT-CTV was 4.1%. Conclusions: Imaging with PET/CT for preoperative radiotherapy of rectal cancer may lead to a change in staging and target volume delineation. Stage variation was observed in 12% of cases and a change of treatment intent in 4%. The GTV and CTV changed significantly, with a mean increase in size of 25% and 4%, respectively

PET/CT and radiotherapy

International Nuclear Information System (INIS)

Messa, C.; CNR, Milano; S. Gerardo Hospital, Monza; Di Muzio, N.; Picchio, M.; Bettinardi, V.; Gilardi, M.C.; CNR, Milano; San Raffaele Scientific Institute, Milano; Fazio, F.; CNR, Milano; San Raffaele Scientific Institute, Milano; San Raffaele Scientific Institute, Milano

2006-01-01

This article reviews the state of the art of PET/CT applications in radiotherapy, specifically its use in disease staging, patient selection, treatment planning and treatment evaluation. Diseases for which radiotherapy with radical intent is indicated will be considered, as well as those in which PET/CT may actually change the course of disease. The methodological and technological aspects of PET/CT in radiotherapy are discussed, focusing on the problem of target volume definition with CT and PET functional imaging and the problem of tumor motion with respect to imaging and dose delivery

Automatic definition of targeted biological volumes for the radiotherapy applications; Definition automatique des volumes biologiques cibles pour les applications de radiotherapie

Energy Technology Data Exchange (ETDEWEB)

Hatt, M.; Visvikis, D. [LaTIM, U650 Inserm, 29 - Brest (France); Cheze-Le-Rest, C. [Service de medecine nucleaire, 29 - Brest (France); Pradier, O. [Service de radiotherapie, 29 - Brest (France)

2009-10-15

The proposed method: Fuzzy locally adaptive Bayesian (F.L.A.B.) showed its reliability and its precision on very complete collection of realistic simulated and real data. Its use in the context of radiotherapy allows to consider easily the studies implementation and scenari of dose painting or dose escalation, including in complex cases of heterogenous fixations. It is conceivable to apply F.L.A.B. on PET images with F.M.I.S.O. ({sup 18}F fluoro misonidazole) or F.L.T. (fluoro-L-thymidine) to complete the definition of the biological target volume. (N.C.)

Image-guided radiotherapy for effective radiotherapy delivery

CERN Document Server

Karlsson, Ulf Lennart

2016-01-01

Image-guided radiotherapy (IGRT) is a new radiotherapy technology that combines the rapid dose fall off associated with intensity-modulated radiotherapy (IMRT) and daily tumor imaging allowing for high precision tumor dose delivery and effective sparing of surrounding normal organs. The new radiation technology requires close collaboration between radiologists, nuclear medicine specialists, and radiation oncologists to avoid marginal miss. Modern diagnostic imaging such as positron emission tomography (PET) scans, positron emission tomography with Computed Tomograpgy (PET-CT), and magnetic resonance imaging (MRI) allows the radiation oncologist to target the positive tumor with high accuracy. As the tumor is well visualized during radiation treatment, the margins required to avoid geographic miss can be safely reduced , thus sparing the normal organs from excessive radiation. When the tumor is located close to critical radiosensitive structures such as the spinal cord, IGRT can deliver a high dose of radiatio...

Experimental radiotherapy and clinical radiobiology. Vol. 20. Proceedings

International Nuclear Information System (INIS)

Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemannn, Hans-Peter; Zips, Daniel

2011-01-01

The proceedings include contributions on the following issues: laser driven proton accelerators on the way for radiotherapy, radiobiological evaluation of new radiations; molecular factors of radiation response; biological targeting; EGFR epidermal growth factor receptor/targeting - combined internal and external irradiation, radiobiology of normal tissues; dose-volume histograms for the radiotherapy: curves without radiobiological relevance or important information for the therapy planning; HPV (human papilloma virus) and radiation sensitivity of HNSCC (head and neck squamous cell carcinomas): evidence, radiobiological mechanism, clinical consequences and perspectives; mechanisms of action and intertumoral heterogeneity of response to EGFR inhibition in radiotherapy of solid tumors; evaluation of biomarkers for radiotherapy.

Target coverage in image-guided stereotactic body radiotherapy of liver tumors.

Science.gov (United States)

Wunderink, Wouter; Méndez Romero, Alejandra; Vásquez Osorio, Eliana M; de Boer, Hans C J; Brandwijk, René P; Levendag, Peter C; Heijmen, Ben J M

2007-05-01

To determine the effect of image-guided procedures (with computed tomography [CT] and electronic portal images before each treatment fraction) on target coverage in stereotactic body radiotherapy for liver patients using a stereotactic body frame (SBF) and abdominal compression. CT guidance was used to correct for day-to-day variations in the tumor's mean position in the SBF. By retrospectively evaluating 57 treatment sessions, tumor coverage, as obtained with the clinically applied CT-guided protocol, was compared with that of alternative procedures. The internal target volume-plus (ITV(+)) was introduced to explicitly include uncertainties in tumor delineations resulting from CT-imaging artifacts caused by residual respiratory motion. Tumor coverage was defined as the volume overlap of the ITV(+), derived from a tumor delineated in a treatment CT scan, and the planning target volume. Patient stability in the SBF, after acquisition of the treatment CT scan, was evaluated by measuring the displacement of the bony anatomy in the electronic portal images relative to CT. Application of our clinical protocol (with setup corrections following from manual measurements of the distances between the contours of the planning target volume and the daily clinical target volume in three orthogonal planes, multiple two-dimensional) increased the frequency of nearly full (> or = 99%) ITV(+) coverage to 77% compared with 63% without setup correction. An automated three-dimensional method further improved the frequency to 96%. Patient displacements in the SBF were generally small (design, patient stability in the SBF should be verified with portal imaging.

Aptamer-based radiopharmaceuticals for diagnostic imaging and targeted radiotherapy of epithelial tumors

International Nuclear Information System (INIS)

Missailidis, Sotiris; Perkins, Alan; Santos-Filho, Sebastiao David; Fonseca, Adenilson de Souza da; Bernardo-Filho, Mario

2008-01-01

In the continuous search for earlier diagnosis and improved therapeutic modalities against cancer, based on our constantly increasing knowledge of cancer biology, aptamers hold the promise to expand on current antibody success, but overcoming some of the problems faced with antibodies as therapeutic or delivery agents in cancer. However, as the first aptamer reached the market as an inhibitor against angiogenesis for the treatment of macular degeneration, aptamers have found only limited applications or interest in oncology, and even less as radiopharmaceuticals for diagnostic imaging and targeted radiotherapy of tumours. Yet, the chemistry for the labelling of aptamers and the options to alter their pharmacokinetic properties, to make them suitable for use as radiopharmaceuticals is now available and recent advances in their development can demonstrate that these molecules would make them ideal delivery vehicles for the development of targeted radiopharmaceuticals that could deliver their radiation load with accuracy to the tumour site, offering improved therapeutic properties and reduced side effects. (author)

Aptamer-based radiopharmaceuticals for diagnostic imaging and targeted radiotherapy of epithelial tumors

Energy Technology Data Exchange (ETDEWEB)

Missailidis, Sotiris [The Open University, Milton Keynes (United Kingdom). Dept. of Chemistry and Analytical Sciences]. E-mail: s.missailidis@open.ac.uk; Perkins, Alan [University of Nottingham (United Kingdom). Dept. of Medical Physics; Santos-Filho, Sebastiao David; Fonseca, Adenilson de Souza da; Bernardo-Filho, Mario [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Dept. de Biofisica e Biometria

2008-12-15

In the continuous search for earlier diagnosis and improved therapeutic modalities against cancer, based on our constantly increasing knowledge of cancer biology, aptamers hold the promise to expand on current antibody success, but overcoming some of the problems faced with antibodies as therapeutic or delivery agents in cancer. However, as the first aptamer reached the market as an inhibitor against angiogenesis for the treatment of macular degeneration, aptamers have found only limited applications or interest in oncology, and even less as radiopharmaceuticals for diagnostic imaging and targeted radiotherapy of tumours. Yet, the chemistry for the labelling of aptamers and the options to alter their pharmacokinetic properties, to make them suitable for use as radiopharmaceuticals is now available and recent advances in their development can demonstrate that these molecules would make them ideal delivery vehicles for the development of targeted radiopharmaceuticals that could deliver their radiation load with accuracy to the tumour site, offering improved therapeutic properties and reduced side effects. (author)

Clinical target volume delineation in glioblastomas: pre-operative versus post-operative/pre-radiotherapy MRI

Science.gov (United States)

Farace, P; Giri, M G; Meliadò, G; Amelio, D; Widesott, L; Ricciardi, G K; Dall'Oglio, S; Rizzotti, A; Sbarbati, A; Beltramello, A; Maluta, S; Amichetti, M

2011-01-01

Objectives Delineation of clinical target volume (CTV) is still controversial in glioblastomas. In order to assess the differences in volume and shape of the radiotherapy target, the use of pre-operative vs post-operative/pre-radiotherapy T1 and T2 weighted MRI was compared. Methods 4 CTVs were delineated in 24 patients pre-operatively and post-operatively using T1 contrast-enhanced (T1PRECTV and T1POSTCTV) and T2 weighted images (T2PRECTV and T2POSTCTV). Pre-operative MRI examinations were performed the day before surgery, whereas post-operative examinations were acquired 1 month after surgery and before chemoradiation. A concordance index (CI) was defined as the ratio between the overlapping and composite volumes. Results The volumes of T1PRECTV and T1POSTCTV were not statistically different (248 ± 88 vs 254 ± 101), although volume differences >100 cm3 were observed in 6 out of 24 patients. A marked increase due to tumour progression was shown in three patients. Three patients showed a decrease because of a reduced mass effect. A significant reduction occurred between pre-operative and post-operative T2 volumes (139 ± 68 vs 78 ± 59). Lack of concordance was observed between T1PRECTV and T1POSTCTV (CI = 0.67 ± 0.09), T2PRECTV and T2POSTCTV (CI = 0.39 ± 0.20) and comparing the portion of the T1PRECTV and T1POSTCTV not covered by that defined on T2PRECTV images (CI = 0.45 ± 0.16 and 0.44 ± 0.17, respectively). Conclusion Using T2 MRI, huge variations can be observed in peritumoural oedema, which are probably due to steroid treatment. Using T1 MRI, brain shifts after surgery and possible progressive enhancing lesions produce substantial differences in CTVs. Our data support the use of post-operative/pre-radiotherapy T1 weighted MRI for planning purposes. PMID:21045069

A tri-modality image fusion method for target delineation of brain tumors in radiotherapy.

Directory of Open Access Journals (Sweden)

Lu Guo

Full Text Available To develop a tri-modality image fusion method for better target delineation in image-guided radiotherapy for patients with brain tumors.A new method of tri-modality image fusion was developed, which can fuse and display all image sets in one panel and one operation. And a feasibility study in gross tumor volume (GTV delineation using data from three patients with brain tumors was conducted, which included images of simulation CT, MRI, and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET examinations before radiotherapy. Tri-modality image fusion was implemented after image registrations of CT+PET and CT+MRI, and the transparency weight of each modality could be adjusted and set by users. Three radiation oncologists delineated GTVs for all patients using dual-modality (MRI/CT and tri-modality (MRI/CT/PET image fusion respectively. Inter-observer variation was assessed by the coefficient of variation (COV, the average distance between surface and centroid (ADSC, and the local standard deviation (SDlocal. Analysis of COV was also performed to evaluate intra-observer volume variation.The inter-observer variation analysis showed that, the mean COV was 0.14(± 0.09 and 0.07(± 0.01 for dual-modality and tri-modality respectively; the standard deviation of ADSC was significantly reduced (p<0.05 with tri-modality; SDlocal averaged over median GTV surface was reduced in patient 2 (from 0.57 cm to 0.39 cm and patient 3 (from 0.42 cm to 0.36 cm with the new method. The intra-observer volume variation was also significantly reduced (p = 0.00 with the tri-modality method as compared with using the dual-modality method.With the new tri-modality image fusion method smaller inter- and intra-observer variation in GTV definition for the brain tumors can be achieved, which improves the consistency and accuracy for target delineation in individualized radiotherapy.

Change of tumor target volume during waiting time for intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Chen Bo; Yi Junlin; Gao Li; Xu Guozhen; Huang Xiaodong; Zhang Zhong; Luo Jingwei; Li Suyan

2007-01-01

Objective: To determine the influence of change in tumor target volume of nasopharyngeal carcinoma (NPC) while waiting for intensity modulated radiation therapy (IMRT). Methods: From March 2005 to December 2005, 31 patients with nasopharyngeal carcinoma received IMRT as the initial treatment at the Cancer Hospital of Chinese Academic of Medical Sciences. The original simulation CT scan was acquired before IMRT planning. A second CT scan was acquired before the start of radiotherapy. Wait- ing time was defined as the duration between CT simulation and start of radiotherapy. CT-CT fusion was used to minimize the error of delineation between the first tumor target volume (GTV) and the second tumor target volume (sGTV). Tumor target volume was calculated by treatment planning system. T test was carried out to analyse the difference between GTV and sGTV. Pearson correlation and multivariate linear regression was used to analyse the influence factor of the change betweent GTV and sGTV. Results: Median waiting time was 18 days (range, 9-27 days). There were significant differences between GTV and sGTV of both primary tumor (P=0.009) and metastatic lymphoma (P=0.005 ). Both Pearson correlation and multivariate linear regression showed that the change of primary tumor target volume had significant correlation with the first tumor target volume but had no significant correlation with the waiting time, sex, age, T stage and N stage (1992 Chinese Fuzhou Staging Classification). Conclusions: Within the range of the waiting time ob- served in our study, large volume primary tumor would have had a significant increase in volume, but whether the therapeutic effect would be influenced or not would need to be proved by study of large number of cases. Patients with large volume tumor should be considered to reduce the influence of waiting time by enlarging gross target volume and clinical targe volume and by neoadjuveant chemotherapy. For avoiding the unnecessary high-dose to normal

[The need for a paradigm shift in radiotherapy].

Science.gov (United States)

Mayer, Árpád; Katona, Csilla; Farkas, Róbert; Póti, Zsuzsa

2015-11-01

The status and indications of radiotherapy have significantly changed in the past decade because novel techniques, radiobiological research and major advances in informatics have made better local control possible. Using supplemented marking of the target volume with computer tomography based other image-making methods adapted made it possible to define the tumor and intact surrounding tissues more precisely. With novel radiotherapy techniques the dosage of the homogenity and the covering in the target volume can be raised optimally, especially with intensity modulated arc radiotherapy (volumetric modulated arc therapy) without causing radiation injury or damage to intact surrounding tissues. Furthermore, with novel techniques and target volume marking, new indications have appeared in clinical practice and besides stereotactic radiotherapy for intracranial metastases, the extracranial so-called oligometastic conditions can be maintained close to a curative state (or in remission) for many years. Among these, perhaps the most striking is the stereotactic radiotherapy treatment of liver, lung and spinal cord metastases in one or more fractions, for which the indispensable condition is the image or respiratory guided technique.

Adaptive Motion Compensation in Radiotherapy

CERN Document Server

Murphy, Martin J

2011-01-01

External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

Evaluation of the role of 18FDG-PET/CT in radiotherapy target definition in patients with head and neck cancer

Energy Technology Data Exchange (ETDEWEB)

Newbold, Katie L; Partridge, Mike; Cook, Gary; Sharma, Bhupinder; Rhys-Evans, Peter; Harrington, Kevin J; Nutting, Christopher M [The Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom)

2008-08-15

Background and purpose. As techniques for radiotherapy delivery have developed, increasingly accurate localisation of disease is demanded. Functional imaging, particularly PET and its fusion with anatomical modalities, such as PET/CT, promises to improve detection and characterisation of disease. This study evaluated the impact of 18FDG-PET/CT on radiotherapy target volume definition in head and neck cancer (HNC). Materials and methods. The PET/CT scans of patients with HNC were used in a radiotherapy planning (RTP) study. The gross tumour volume (GTV), clinical target volume (CTV) and planning target volume (PTV) were defined conventionally and compared to those defined using the PET/CT. Data were reported as the median value with 95% confidence intervals. Results. Eighteen patients were consented, 9 had known primary tumour site, 9 presented as unknown primary. In nine cases where the primary site was known, the combined primary and nodal GTV (GTVp+n) increased by a median of 6.1cm3 (2.6, 12.2) or 78% (18, 313), p=0.008 with CTV increasing by a median of 10.1cm3 (1.3, 30.6) or 4% (0, 13) p=0.012. In 9 cases of unknown primary the GTVp+n increased by a median 6.3cm3 (0.2, 15.7) or 61% (4, 210), p=0.012, with CTV increasing by a median 155.4cm3 (2.7, 281.7) or 95% (1, 137), p=0.008. Conclusion. 18FDG-PET revealed disease lying outside the conventional target volume, either extending a known area or highlighting a previously unknown area of disease, including the primary tumour in 5 cases. We recommend PET/CT in the RTP of all cases of unknown primary. In patients with a known primary, although the change in volume was statistically significant the clinical impact is less clear. 18FDG-PET can also show areas within the conventional target volume that are hypermetabolic which may be possible biological target volumes for dose escalation studies in the future

Long-term follow-up after modern radical prostate cancer radiotherapy

DEFF Research Database (Denmark)

Sander, Lotte

that clinical target volumes are up to 30% smaller on MRI delineation compared to computer tomography delineation. The overall aim of the thesis was to explore the use of MRI target planning and a Nicle-Titanium prostate stent as fiducial marker for both MR-CT co-registration and image guided radiotherapy....... radiotherapy is a well established treatment modality for prostate cancer. Accuracy and precision are key words with regard to optimal survival and minimal toxicity in modern radiotherapy and are fundamentals in modern radiotherapy. Modern imaging has improved the ability to define radiotherapy target volumes......A significant increase in the prostate cancer incidence has made prostate cancer a major health problem in recent years. Because of the often but unfortunately not always indolent nature of the disease, over-diagnosis and over-treatment are relevant clinical and ethic dilemmas. External beam...

Cone beam CT with zonal filters for simultaneous dose reduction, improved target contrast and automated set-up in radiotherapy

International Nuclear Information System (INIS)

Moore, C J; Marchant, T E; Amer, A M

2006-01-01

Cone beam CT (CBCT) using a zonal filter is introduced. The aims are reduced concomitant imaging dose to the patient, simultaneous control of body scatter for improved image quality in the tumour target zone and preserved set-up detail for radiotherapy. Aluminium transmission diaphragms added to the CBCT x-ray tube of the Elekta Synergy TM linear accelerator produced an unattenuated beam for a central 'target zone' and a partially attenuated beam for an outer 'set-up zone'. Imaging doses and contrast noise ratios (CNR) were measured in a test phantom for transmission diaphragms 12 and 24 mm thick, for 5 and 10 cm long target zones. The effect on automatic registration of zonal CBCT to conventional CT was assessed relative to full-field and lead-collimated images of an anthropomorphic phantom. Doses along the axis of rotation were reduced by up to 50% in both target and set-up zones, and weighted dose (two thirds surface dose plus one third central dose) was reduced by 10-20% for a 10 cm long target zone. CNR increased by up to 15% in zonally filtered CBCT images compared to full-field images. Automatic image registration remained as robust as that with full-field images and was superior to CBCT coned down using lead-collimation. Zonal CBCT significantly reduces imaging dose and is expected to benefit radiotherapy through improved target contrast, required to assess target coverage, and wide-field edge detail, needed for robust automatic measurement of patient set-up error

A clip-based protocol for breast boost radiotherapy provides clear target visualisation and demonstrates significant volume reduction over time

Energy Technology Data Exchange (ETDEWEB)

Lewis, Lorraine [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Cox, Jennifer [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Faculty of Health Sciences, University of Sydney, Sydney, New South Wales (Australia); Morgia, Marita [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Atyeo, John [Faculty of Health Sciences, University of Sydney, Sydney, New South Wales (Australia); Lamoury, Gillian [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia)

2015-09-15

The clinical target volume (CTV) for early stage breast cancer is difficult to clearly identify on planning computed tomography (CT) scans. Surgical clips inserted around the tumour bed should help to identify the CTV, particularly if the seroma has been reabsorbed, and enable tracking of CTV changes over time. A surgical clip-based CTV delineation protocol was introduced. CTV visibility and its post-operative shrinkage pattern were assessed. The subjects were 27 early stage breast cancer patients receiving post-operative radiotherapy alone and 15 receiving post-operative chemotherapy followed by radiotherapy. The radiotherapy alone (RT/alone) group received a CT scan at median 25 days post-operatively (CT1rt) and another at 40 Gy, median 68 days (CT2rt). The chemotherapy/RT group (chemo/RT) received a CT scan at median 18 days post-operatively (CT1ch), a planning CT scan at median 126 days (CT2ch), and another at 40 Gy (CT3ch). There was no significant difference (P = 0.08) between the initial mean CTV for each cohort. The RT/alone cohort showed significant CTV volume reduction of 38.4% (P = 0.01) at 40 Gy. The Chemo/RT cohort had significantly reduced volumes between CT1ch: median 54 cm{sup 3} (4–118) and CT2ch: median 16 cm{sup 3}, (2–99), (P = 0.01), but no significant volume reduction thereafter. Surgical clips enable localisation of the post-surgical seroma for radiotherapy targeting. Most seroma shrinkage occurs early, enabling CT treatment planning to take place at 7 weeks, which is within the 9 weeks recommended to limit disease recurrence.

A clip-based protocol for breast boost radiotherapy provides clear target visualisation and demonstrates significant volume reduction over time

International Nuclear Information System (INIS)

Lewis, Lorraine; Cox, Jennifer; Morgia, Marita; Atyeo, John; Lamoury, Gillian

2015-01-01

The clinical target volume (CTV) for early stage breast cancer is difficult to clearly identify on planning computed tomography (CT) scans. Surgical clips inserted around the tumour bed should help to identify the CTV, particularly if the seroma has been reabsorbed, and enable tracking of CTV changes over time. A surgical clip-based CTV delineation protocol was introduced. CTV visibility and its post-operative shrinkage pattern were assessed. The subjects were 27 early stage breast cancer patients receiving post-operative radiotherapy alone and 15 receiving post-operative chemotherapy followed by radiotherapy. The radiotherapy alone (RT/alone) group received a CT scan at median 25 days post-operatively (CT1rt) and another at 40 Gy, median 68 days (CT2rt). The chemotherapy/RT group (chemo/RT) received a CT scan at median 18 days post-operatively (CT1ch), a planning CT scan at median 126 days (CT2ch), and another at 40 Gy (CT3ch). There was no significant difference (P = 0.08) between the initial mean CTV for each cohort. The RT/alone cohort showed significant CTV volume reduction of 38.4% (P = 0.01) at 40 Gy. The Chemo/RT cohort had significantly reduced volumes between CT1ch: median 54 cm 3 (4–118) and CT2ch: median 16 cm 3 , (2–99), (P = 0.01), but no significant volume reduction thereafter. Surgical clips enable localisation of the post-surgical seroma for radiotherapy targeting. Most seroma shrinkage occurs early, enabling CT treatment planning to take place at 7 weeks, which is within the 9 weeks recommended to limit disease recurrence

Scanned proton radiotherapy for mobile targets-the effectiveness of re-scanning in the context of different treatment planning approaches and for different motion characteristics

NARCIS (Netherlands)

Knopf, Antje-Christin; Hong, Theodore S; Lomax, Antony

2011-01-01

The most advanced delivery technique for proton radiotherapy is active spot scanning. So far, predominantly static targets have been treated with active spot scanning, since mobile targets in combination with dynamic treatment delivery can lead to interplay effects, causing inhomogeneous dose

Superior target delineation for stereotactic body radiotherapy of bone metastases from renal cell carcinoma on MRI compared to CT

NARCIS (Netherlands)

Prins, Fieke M.; Van Der Velden, Joanne M.; Gerlich, Anne S.; Kotte, Alexis N.T.J.; Eppinga, Wietse S.C.; Kasperts, Nicolien; Verlaan, Jorrit J.; Pameijer, Frank A.; Kerkmeijer, Linda G.W.

2017-01-01

Background: In metastatic renal cell carcinoma (mRCC) there has been a treatment shift towards targeted therapy, which has resulted in improved overall survival. Therefore, there is a need for better local control of the tumor and its metastases. Image-guided stereotactic body radiotherapy (SBRT) in

Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

CERN Document Server

Lemoigne, Yves

2009-01-01

This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...

135La as an auger-electron emitter for targeted internal radiotherapy

DEFF Research Database (Denmark)

Fonslet, Jesper; Lee, Boon Quan; Tran, Thuy A.

2018-01-01

Introduction: 135La has favorable nuclear and chemical properties for Auger-based targeted internal radiotherapy. Here we present detailed investigations of the production, emissions, imaging characteristics, and dosimetry related to 135La therapy. Methods and Results: 135La was produced by 16.5 Me....... The generated Auger spectrum was used to recalculate cellular S-factors. Conclusion: 135La was produced with high specific activity, reactivity, radionuclidic purity, and yield. The emission spectrum and the dosimetry are favorable for internal radionuclide therapy. ....... recovered > 98 % of the 135La with an effective molar activity of 70 ±20 GBq/µmol. To better assess cellular and organ dosimetry of this nuclide, we have recalculated the X-ray and Auger emission spectra using a Monte Carlo model accounting for effects of multiple vacancies during the Auger cascade...

Histopathological correlation of 11C-choline PET scans for target volume definition in radical prostate radiotherapy

International Nuclear Information System (INIS)

Chang, Joe H.; Joon, Daryl Lim; Lee, Sze Ting; Gong, Sylvia J.; Scott, Andrew M.; Davis, Ian D.; Clouston, David; Bolton, Damien; Hamilton, Christopher S.; Khoo, Vincent

2011-01-01

Background and purpose: To evaluate the accuracy of 11 C-choline PET scans in defining dominant intraprostatic lesions (DILs) for radiotherapy target volume definition. Material and methods: Eight men with prostate cancer who had 11 C-choline PET scans prior to radical prostatectomy were studied. Several methods were used to contour the DIL on the PET scans: visual, PET Edge, Region Grow, absolute standardised uptake value (SUV) thresholds and percentage of maximum SUV thresholds. Prostatectomy specimens were sliced in the transverse plane and DILs were delineated on these by a pathologist. These were then compared with the PET scans. The accuracy of correlation was assessed by the Dice similarity coefficient (DSC) and the Youden index. Results: The contouring method resulting in both the highest DSC and the highest Youden index was 60% of the maximum SUV (SUV 60% ), with values of 0.64 and 0.51, respectively. However SUV 60% was not statistically significantly better than all of the other methods by either measure. Conclusions: Although not statistically significant, SUV 60% resulted in the best correlation between 11 C-choline PET and pathology amongst all the methods studied. The degree of correlation shown here is consistent with previous studies that have justified using imaging for DIL radiotherapy target volume definition.

Implications of improved diagnostic imaging of small nodal metastases in head and neck cancer: Radiotherapy target volume transformation and dose de-escalation.

Science.gov (United States)

van den Bosch, Sven; Vogel, Wouter V; Raaijmakers, Cornelis P; Dijkema, Tim; Terhaard, Chris H J; Al-Mamgani, Abrahim; Kaanders, Johannes H A M

2018-05-03

Diagnostic imaging continues to evolve, and now has unprecedented accuracy for detecting small nodal metastasis. This influences the tumor load in elective target volumes and subsequently has consequences for the radiotherapy dose required to control disease in these volumes. Small metastases that used to remain subclinical and were included in elective volumes, will nowadays be detected and included in high-dose volumes. Consequentially, high-dose volumes will more often contain low-volume disease. These target volume transformations lead to changes in the tumor burden in elective and "gross" tumor volumes with implications for the radiotherapy dose prescribed to these volumes. For head and neck tumors, nodal staging has evolved from mere palpation to combinations of high-resolution imaging modalities. A traditional nodal gross tumor volume in the neck typically had a minimum diameter of 10-15 mm, while nowadays much smaller tumor deposits are detected in lymph nodes. However, the current dose levels for elective nodal irradiation were empirically determined in the 1950s, and have not changed since. In this report the radiobiological consequences of target volume transformation caused by modern imaging of the neck are evaluated, and theoretically derived reductions of dose in radiotherapy for head and neck cancer are proposed. The concept of target volume transformation and subsequent strategies for dose adaptation applies to many other tumor types as well. Awareness of this concept may result in new strategies for target definition and selection of dose levels with the aim to provide optimal tumor control with less toxicity. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Quality indicators in radiotherapy

International Nuclear Information System (INIS)

Cionini, Luca; Gardani, Gianstefano; Gabriele, Pietro; Magri, Secondo; Morosini, Pier Luigi; Rosi, Antonella; Viti, Vincenza

2007-01-01

Background and purpose: There is a widespread and increasing tendency to develop hospital performance indicators in the field of accreditation/certification systems and quality benchmarking. A study has been undertaken to develop a set of performance indicators for a typical radiotherapy Centre and to evaluate their ability to provide a continuous quality improvement. Materials and methods: A working group consisting of radiation oncologists, medical physicists and radiation technologists under the coordination of experts in health technology assessment has elaborated a set of general indicators able to monitor performances and the quality level of a typical radiotherapy Centre. The work has been carried out through four steps: a preliminary set of indicators was selected; data on these indicators were collected in a number of Italian radiotherapy Centres and medical physics Services; problems in collection and analysis of data were discussed; a final set of indicators was developed. Results: A final set of 13 indicators is here presented. They concern general structural and/or operational features, health physics activities and accuracy and technical complexity of the treatment. Conclusions: The indicators tested in a few Italian Centres of radiotherapy and medical physics Services are now ready to be utilized by a larger community

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

International Nuclear Information System (INIS)

Rank, Christopher M; Tremmel, Christoph; Hünemohr, Nora; Nagel, Armin M; Jäkel, Oliver; Greilich, Steffen

2013-01-01

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

MRI target delineation may reduce long-term toxicity after prostate radiotherapy.

Science.gov (United States)

Sander, Lotte; Langkilde, Niels Christian; Holmberg, Mats; Carl, Jesper

2014-06-01

Aiming for minimal toxicity after radical prostate cancer (PC) radiotherapy (RT), magnetic resonance imaging (MRI) target delineation could be a possible benefit knowing that clinical target volumes (CTV) are up to 30% smaller, when CTV delineation on MRI is compared to standard computed tomography (CT). This study compares long-term toxicity using CT or MRI delineation before PC RT. Urinary and rectal toxicity assessments 36 months after image-guided RT (78 Gy) using CTC-AE scores in two groups of PC patients. Peak symptom score values were registered. One group of patients (n=72) had standard CT target delineation and gold markers as fiducials. Another group of patients (n=73) had MRI target delineation and a nickel-titanium stent as fiducial. At 36 months no difference in overall survival (92% in both groups, p=0.29) or in PSA-relapse free survival was found between the groups (MRI=89% and CT=94%, p=0.67). A significantly smaller CTV was found in the MRI group (p=0.02). Urinary retention and frequency were significantly reduced in the MRI group (p=0.03 in the matter of both). The overall urinary and rectal toxicity did not differ between the two groups. MRI delineation leads to a significantly reduced CTV. Significantly lower urinary frequency and urinary retention toxicity scores were observed following MRI delineation. The study did not find significant differences in overall urinary or rectal toxicity between the two groups. PSA-relapse survival did not differ between the two groups at 36 months.

Persistent pain after targeted intraoperative radiotherapy (TARGIT) or external breast radiotherapy for breast cancer: A randomized trial

DEFF Research Database (Denmark)

Andersen, Kenneth Geving; Gärtner, Rune; Kroman, Niels

2012-01-01

for participation, and a total of 244 patients were included and received a detailed questionnaire. The response rate was 98%, leaving 238 patients for the final analysis. Pain prevalence were 33.9% in the EBRT group and 24.6% in the IORT group (p = 0.11). Treatment with IORT may not alter the risk of PPBCT.......Persistent pain after breast cancer treatment (PPBCT) affects between 25 and 60% of patients depending on surgical and adjuvant treatment. External breast radiotherapy (EBRT) has been shown to be a riskfactor for PPBCT, raising the question whether intraoperative radiation therapy (IORT), with its...... smaller radiation field may reduce the development of PPBCT. Using data from the TARGIT-A trial, the aim of this study was to compare these two treatments with regard to development of PPBCT. A total of 281 patients enrolled in the TARGIT-A trial from the Copenhagen University Hospitals was screened...

Epigenetics in radiotherapy: Where are we heading?

International Nuclear Information System (INIS)

Smits, Kim M.; Melotte, Veerle; Niessen, Hanneke E.C.; Dubois, Ludwig; Oberije, Cary; Troost, Esther G.C.; Starmans, Maud H.W.; Boutros, Paul C.; Vooijs, Marc; Engeland, Manon van; Lambin, Philippe

2014-01-01

Radiotherapy is an important component of anti-cancer treatment. However, not all cancer patients respond to radiotherapy, and with current knowledge clinicians are unable to predict which patients are at high risk of recurrence after radiotherapy. There is therefore an urgent need for biomarkers to guide clinical decision-making. Although the importance of epigenetic alterations is widely accepted, their application as biomarkers in radiotherapy has not been studied extensively. In addition, it has been suggested that radiotherapy itself introduces epigenetic alterations. As epigenetic alterations can potentially be reversed by drug treatment, they are interesting candidate targets for anticancer therapy or radiotherapy sensitizers. The application of demethylating drugs or histone deacetylase inhibitors to sensitize patients for radiotherapy has been studied in vitro, in vivo as well as in clinical trials with promising results. This review describes the current knowledge on epigenetics in radiotherapy

A treatment planning comparison of four target volume contouring guidelines for locally advanced pancreatic cancer radiotherapy

International Nuclear Information System (INIS)

Fokas, Emmanouil; Eccles, Cynthia; Patel, Neel; Chu, Kwun-Ye; Warren, Samantha; McKenna, W. Gillies; Brunner, Thomas B.

2013-01-01

Background and purpose: Contouring of target volumes varies significantly in radiotherapy of pancreatic ductal adenocarcinoma (PDAC). There is a lack of consensus as to whether elective lymph nodes (eLN’s) should be included or not in the planning target volume (PTV). In the present study we analyzed the dosimetric coverage of the eLN’s and organs at risk (OAR) by comparing four different contouring guidelines. Methods and materials: PTVs were delineated with (Oxford and RTOG guidelines) or without (Michigan and SCALOP guidelines) including the eLNs in eleven patients with PDAC. eLNs included the peripancreatic, paraaortic, paracaval, celiac trunk, superior mesenteric and portal vein clinical target volumes (CTVs). A 3D-CRT plan (50.40 Gy in 28 fractions) was performed to analyze and compare the dosimetric coverage of all eLNs and OAR between the 4 contouring guidelines. Results: The size of Oxford and RTOG PTVs was comparable and significantly larger than the SCALOP and Michigan PTVs. Interestingly the eLNs received a significant amount of incidental dose irradiation by PTV-based plans that only aimed to treat the tumor without the eLNs. The dosimetric coverage of eLN presented a large variability according to the respective contouring methods. The difference in the size of the 4 PTVs was reflected to the dose distribution at the OAR. Conclusions: Our study provides important information regarding the impact of different contouring guidelines on the dose distribution to the eLNs and the OAR in patients with locally advanced PDAC treated with radiotherapy

Target Coverage in Image-Guided Stereotactic Body Radiotherapy of Liver Tumors

International Nuclear Information System (INIS)

Wunderink, Wouter; Romero, Alejandra Mendez; Osorio, Eliana M. Vasquez; Boer, Hans C.J. de; Brandwijk, Rene P.; Levendag, Peter C.; Heijmen, Ben

2007-01-01

Purpose: To determine the effect of image-guided procedures (with computed tomography [CT] and electronic portal images before each treatment fraction) on target coverage in stereotactic body radiotherapy for liver patients using a stereotactic body frame (SBF) and abdominal compression. CT guidance was used to correct for day-to-day variations in the tumor's mean position in the SBF. Methods and Materials: By retrospectively evaluating 57 treatment sessions, tumor coverage, as obtained with the clinically applied CT-guided protocol, was compared with that of alternative procedures. The internal target volume-plus (ITV + ) was introduced to explicitly include uncertainties in tumor delineations resulting from CT-imaging artifacts caused by residual respiratory motion. Tumor coverage was defined as the volume overlap of the ITV + , derived from a tumor delineated in a treatment CT scan, and the planning target volume. Patient stability in the SBF, after acquisition of the treatment CT scan, was evaluated by measuring the displacement of the bony anatomy in the electronic portal images relative to CT. Results: Application of our clinical protocol (with setup corrections following from manual measurements of the distances between the contours of the planning target volume and the daily clinical target volume in three orthogonal planes, multiple two-dimensional) increased the frequency of nearly full (≥99%) ITV + coverage to 77% compared with 63% without setup correction. An automated three-dimensional method further improved the frequency to 96%. Patient displacements in the SBF were generally small (≤2 mm, 1 standard deviation), but large craniocaudal displacements (maximal 7.2 mm) were occasionally observed. Conclusion: Daily, CT-assisted patient setup may substantially improve tumor coverage, especially with the automated three-dimensional procedure. In the present treatment design, patient stability in the SBF should be verified with portal imaging

DEGRO practical guidelines. Radiotherapy of breast cancer I. Radiotherapy following breast conserving therapy for invasive breast cancer

International Nuclear Information System (INIS)

Sedlmayer, F.

2013-01-01

Background and purpose: The aim of the present paper is to update the practical guidelines for postoperative adjuvant radiotherapy of breast cancer published in 2007 by the breast cancer expert panel of the German Society for Radiooncology (Deutsche Gesellschaft fuer Radioonkologie, DEGRO). The present recommendations are based on a revision of the German interdisciplinary S-3 guidelines published in July 2012. Methods: A comprehensive survey of the literature concerning radiotherapy following breast conserving therapy (BCT) was performed using the search terms 'breast cancer', 'radiotherapy', and 'breast conserving therapy'. Data from lately published meta-analyses, recent randomized trials, and guidelines of international breast cancer societies, yielding new aspects compared to 2007, provided the basis for defining recommendations according to the criteria of evidence-based medicine. In addition to the more general statements of the DKG (Deutsche Krebsgesellschaft), this paper addresses indications, target definition, dosage, and technique of radiotherapy of the breast after conservative surgery for invasive breast cancer. Results: Among numerous reports on the effect of radiotherapy during BCT published since the last recommendations, the recent EBCTCG report builds the largest meta-analysis so far available. In a 15 year follow-up on 10,801 patients, whole breast irradiation (WBI) halves the average annual rate of disease recurrence (RR 0.52, 0.48-0.56) and reduces the annual breast cancer death rate by about one sixth (RR 0.82, 0.75-0.90), with a similar proportional, but different absolute benefit in prognostic subgroups (EBCTCG 2011). Furthermore, there is growing evidence that risk-adapted dose augmentation strategies to the tumor bed as well as the implementation of high precision RT techniques (e.g., intraoperative radiotherapy) contribute substantially to a further reduction of local relapse rates. A main focus of ongoing research lies in partial breast

Computerised tomography in radiotherapy planning

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Badcock, P.C.

1983-01-01

This study evaluates the effectiveness of computed tomography as an adjunct to radiotherapy planning. Until recently, acquisition of accurate data concerning tumour anatomy lagged behind other developments in radiotherapy. With the advent of computer-tomography (CT), these data can be displayed and transmitted to a treatment planning computer. It is concluded that the greatest inaccuracies in the radiation treatment of patients are to be found in both the inadequate delineation of the target volume within the patient and changes in body outline relative to the target volume over the length of the irradiated volume. The technique was useful in various subgroups (pelvic, intra-thoracic and chest-wall tumours) and for those patients being treated palliatively. With an estimated improvement in cure rate of 4.5% and cost-effective factors of between 3.3 and 5, CT-assisted radiotherapy planning appears to be a worthwhile procedure. (orig.)

Standardization of radiotherapy for less radio-curable malignancies

Energy Technology Data Exchange (ETDEWEB)

Asakawa, Hiroshi; Yamada, Shogo [Miyagi Prefectural Adult Disease Center, Natori (Japan)

1982-09-01

Standardization of radiotherapy for esophageal and gastric cancer was discussed, as the representatives of less radio-curable malignancies. In esophageal carcinoma, it was concluded that radiotherapy should be valuable as a curative procedure. The curative indications for radiotherapy should be the cases of T1-2 N0-1M0 with tumorous or some ulcerous types of carcinoma. Target volume should be defined to the small region, including the primary tumor and the regional lymph node (N1). The dose of 60 to 70 Gy should be optimal and given with the homogeneity of 90%. In gastric carcinoma, it seemed that radiotherapy was a palliative treatment for inoperable carcinoma and should be indicated for the cases of T1-3NxM0 with radio-responsive tumor. Target volume should be localized to the primary lesion and the dose of 50 to 60 Gy should be given as the maximum. Split course radiotherapy was recommended to avoid the serious complications.

Helical tomo-therapy in the anal canal cancer: dosimetric comparison with conformal radiotherapy with intensity modulation and classical conformal radiotherapy

International Nuclear Information System (INIS)

Ozsahin, M.; Ugurluer, G.; Ballerini, G.; Letenneur, G.; Zouhair, A.; Mirimanoff, R.O.

2009-01-01

A dosimetry comparison was made between helical tomo-therapy, I.M.R.T. and classical conformal three dimensional radiotherapy for twelve first patients that received a image guided radiotherapy, the toxicity was tackled with a minimum follow-up of fourteen months. In conclusion, the CT-guided radiotherapy allows to save organs at risks superior to I.M.R.T. and conformal radiotherapy and a best homogeneity in the target volume. the toxicity is moderated and the break time is limited. (N.C.)

What margins should be added to the clinical target volume in radiotherapy treatment planning of lung cancer?

International Nuclear Information System (INIS)

Ekberg, L.; Wittgren, L.; Holmberg, O.

1995-01-01

When defining the planning target volume (PTV) in radiotherapy treatment planning, it is vital to add geometrical margins of normal tissue around the clinical target volume (CTV). This is to ensure that the whole CTV will receive the planned absorbed dose taking into account both set-up deviations and target movements as well as other geometrical variations in the treatment chain. The problem is our limited knowledge of how large these margins should be. To assess the size of needed margins around the CTV in conformal radiotherapy of lung cancer, electronic portal imaging was employed in 232 irradiation field set-ups of 14 patients. This was done in order to quantify the uncertainty in the execution of treatment considering patient movement and set-up displacements. For an estimation of the added geometrical variation from target movement during irradiation, fluoroscopy was used at the simulation of the irradiation fields. The set-up study showed an average systematic deviation for all individual fields of 3.1 mm and an average maximal systematic deviation (in either transversal or craniocaudal direction) of 4.8 mm. The random errors can be described by an average standard deviation of 2.8 mm for all fields in either direction. Major gradual displacements as a function of time was also detected in one of the patients. CTV-movements of several millimetres during respiration could be observed. It was also seen that heartbeats could add to CTV-movements during irradiation with an equal magnitude. The combined effect of these factors are considered when making an overall estimation of margins that should be added to the CTV

Radiotherapy and 'new' drugs-new side effects?

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Niyazi, Maximilian; Maihoefer, Cornelius; Krause, Mechthild; Rödel, Claus; Budach, Wilfried; Belka, Claus

2011-01-01

Targeted drugs have augmented the cancer treatment armamentarium. Based on the molecular specificity, it was initially believed that these drugs had significantly less side effects. However, currently it is accepted that all of these agents have their specific side effects. Based on the given multimodal approach, special emphasis has to be placed on putative interactions of conventional cytostatic drugs, targeted agents and other modalities. The interaction of targeted drugs with radiation harbours special risks, since the awareness for interactions and even synergistic toxicities is lacking. At present, only limited is data available regarding combinations of targeted drugs and radiotherapy. This review gives an overview on the current knowledge on such combined treatments. Using the following MESH headings and combinations of these terms pubmed database was searched: Radiotherapy AND cetuximab/trastuzumab/panitumumab/nimotuzumab, bevacizumab, sunitinib/sorafenib/lapatinib/gefitinib/erlotinib/sirolimus, thalidomide/lenalidomide as well as erythropoietin. For citation crosscheck the ISI web of science database was used employing the same search terms. Several classes of targeted substances may be distinguished: Small molecules including kinase inhibitors and specific inhibitors, antibodies, and anti-angiogenic agents. Combination of these agents with radiotherapy may lead to specific toxicities or negatively influence the efficacy of RT. Though there is only little information on the interaction of molecular targeted radiation and radiotherapy in clinical settings, several critical incidents are reported. The addition of molecular targeted drugs to conventional radiotherapy outside of approved regimens or clinical trials warrants a careful consideration especially when used in conjunction in hypo-fractionated regimens. Clinical trials are urgently needed in order to address the open question in regard to efficacy, early and late toxicity

Standard and Nonstandard Craniospinal Radiotherapy Using Helical TomoTherapy

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Parker, William; Brodeur, Marylene; Roberge, David; Freeman, Carolyn

2010-01-01

Purpose: To show the advantages of planning and delivering craniospinal radiotherapy with helical TomoTherapy (TomoTherapy Inc., Madison, WI) by presenting 4 cases treated at our institution. Methods and Materials: We first present a standard case of craniospinal irradiation in a patient with recurrent myxopapillary ependymoma (MPE) and follow this with 2 cases requiring differential dosing to multiple target volumes. One of these, a patient with recurrent medulloblastoma, required a lower dose to be delivered to the posterior fossa because the patient had been previously irradiated to the full dose, and the other required concurrent boosts to leptomeningeal metastases as part of his treatment for newly diagnosed MPE. The final case presented is a patient with pronounced scoliosis who required spinal irradiation for recurrent MPE. Results: The four cases presented were planned and treated successfully with Helical Tomotherapy. Conclusions: Helical TomoTherapy delivers continuous arc-based intensity-modulated radiotherapy that gives high conformality and excellent dose homogeneity for the target volumes. Increased healthy tissue sparing is achieved at higher doses albeit at the expense of larger volumes of tissue receiving lower doses. Helical TomoTherapy allows for differential dosing of multiple targets, resulting in very elegant dose distributions. Daily megavoltage computed tomography imaging allows for precision of patient positioning, permitting a reduction in planning margins and increased healthy tissue sparing in comparison with standard techniques.

Effects of three-dimensional conformal radiotherapy, indensity modulated radiotherapy, and conventional radiotherapy ON treatment of esophageal cancer

Directory of Open Access Journals (Sweden)

Jian-Jun Han

2016-07-01

Full Text Available Objective: To compare the irradiation volume, short-term and long-term efficacy of conventional radiotherapy (CR, three-dimensional conformal radiotherapy (3D-CRT, and indensity modulated radiotherapy (IMRT in the treatment of esophageal cancer. Methods: A retrospective analysis method was adopted. The patients were divided into CR group (n=42, 3D-CRT group (n=45, and IMRT group (n=40. A follow-up visit was paid to collect the short-term and long-term efficacy, and the occurrence of adverse reactions. The gross tumor voluem (GTV, clinical target volume (CTV, planning target volume (PTV, and irradiation volume of organs (bilateral lungs, spinal cord, and heart at risk (OAR in the three groups were compared. Results: It was found by target volume comparison that the mean values of GTV, CTV, and PTV in the three groups were significantly increased (P0.05. The occurrence rate of adverse reactions in 3D-CRT group and IMRT group was significantly lower than that in CR group (P0.05. The difference of 1-year survival rate among the three groups was not statistically significant (P=0.144, but 3-year and 5-year survival rates in 3D-CRT group and IMRT group were significantly higher than those in CR group (P<0.05. Conclusions: 3D-CRT and IMRT can significantly enhance the short-term and long-term efficacy for esophageal cancer patients, and alleviate the radioactive damage; therefore, they are deserved to be widely recommended in the clinic.

Magnetic Resonance Imaging and conformal radiotherapy: Characterization of MRI alone simulation for conformal radiotherapy. Development and evaluation of an automatic volumes of interest segmentation tool for prostate cancer radiotherapy

International Nuclear Information System (INIS)

Pasquier, David

2006-01-01

Radiotherapy is a curative treatment of malignant tumours. Radiotherapy techniques considerably evolved last years with the increasing integration of medical images in conformal radiotherapy. This technique makes it possible to elaborate a complex ballistics conforming to target volume and sparing healthy tissues. The examination currently used to delineate volumes of interest is Computed Tomography (CT), on account of its geometrical precision and the information that it provides on electronic densities needed to dose calculation. Magnetic Resonance Imaging (MRI) ensures a more precise delineation of target volumes in many locations, such as pelvis and brain. For pelvic tumours, the use of MRI needs image registration, which complicates treatment planning and poses the problem of the lack of in vivo standard method of validation. The obstacles in the use of MRI alone in treatment planning were evaluated. Neither geometrical distortion linked with the system and the patient nor the lack of information on electronic densities represent stumbling obstacles. Distortion remained low even in edge of large field of view on modern machines. The assignment of electronic densities to bone structures and soft tissues in MR images permitted to obtain equivalent dosimetry to that carried out on the original CT, with a good reproducibility and homogeneous distribution within target volume. The assignment of electronic densities could not be carried out using 20 MV photons and suitable ballistics. The development of Image Guided Radiotherapy could facilitate the use of MRI alone in treatment planning. Target volumes and organ at risk delineation is a time consuming task in radiotherapy planning. We took part in the development and evaluated a method of automatic and semi automatic delineation of volumes of interest from MRI images for prostate cancer radiotherapy. For prostate and organ at risk automatic delineation an organ model-based method and a seeded region growing method

Radiotherapy and oral cancer

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Sealy, R [Cape Town Univ. (South Africa). Dept. of Radiotherapy

1982-08-01

A general review article for the non-radiotherapist. The historical, physical and biological background is briefly reviewed. Mention is made of the effects of fraction size, hyperbaric oxygen, neutron beams and radiation sensitizers. The use of chemotherapy and radiotherapy is discussed, as well as the selection of patients for radiotherapy and the treatment of neck nodes. The author suggests a therapeutic approach to the various disease sites and finally reviews some of the literature on radiation caries and jaw necrosis.

Reduced rectal toxicity with ultrasound-based image guided radiotherapy using BAT trademark (B-mode acquisition and targeting system) for prostate cancer

International Nuclear Information System (INIS)

Bohrer, Markus; Schroeder, Peter; Welzel, Grit; Wertz, Hansjoerg; Lohr, Frank; Wenz, Frederik; Mai, Sabine Kathrin

2008-01-01

To evaluate the effect of image guided radiotherapy with stereotactic ultrasound BAT (B-mode acquisition and targeting system) on rectal toxicity in conformal radiotherapy of prostate cancer. Patients and Methods 42 sequential patients with prostate cancer undergoing radiotherapy before and after the introduction of BAT were included. Planning computed tomography (CT) was performed with empty rectum and moderately filled bladder. The planning target volume (PTV) included the prostate and seminal vesicles with a safety margin of 1.5 cm in anterior and lateral direction. In posterior direction the anterior 1/3 of the rectum circumference were included. Total dose was 66 Gy and a boost of 4 Gy excluding the seminal vesicles. 22 patients (BAT group) were treated with daily stereotactic ultrasound positioning, for the other 20 patients (NoBAT group) an EPID (electronic portal imaging device) was performed once a week. Acute and late genito-urinary (GU) and rectal toxicity and PSA values were evaluated after 1.5, 3, 6, 9 and 12 months. The total median follow up of toxicity was 3 years in the BAT group and 4 years in the NoBAT group. Results In the NoBAT group significant more rectal toxicity occurred, while in GU toxicity no difference was seen. Two patients in the NoBAT group showed late rectal toxicity grade 3, no toxicity > grade 2 occurred in the BAT group. There was no significant difference in PSA reduction between the groups. Conclusion Without BAT significant more acute and a trend to more late rectal toxicity was found. With regard to dose escalation this aspect is currently evaluated with a larger number of patients using intensity-modulated radiotherapy (IMRT). (orig.)

Chest wall desmoid tumours treated with definitive radiotherapy: a plan comparison of 3D conformal radiotherapy, intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy

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Liu, Jia; Ng, Diana; Lee, James; Stalley, Paul; Hong, Angela

2016-01-01

Definitive radiotherapy is often used for chest wall desmoid tumours due to size or anatomical location. The delivery of radiotherapy is challenging due to the large size and constraints of normal surrounding structures. We compared the dosimetry of 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) to evaluate the best treatment option. Ten consecutive patients with inoperable chest wall desmoid tumours (PTV range 416–4549 cm 3 ) were selected. For each patient, 3DCRT, IMRT and VMAT plans were generated and the Conformity Index (CI), organ at risk (OAR) doses and monitor unit (MU) were evaluated. The Wilcoxon signed-rank test was used to compare dose delivered to both target and OARs. The mean number of fields for 3DCRT and IMRT were 6.3 ± 2.1, 7.2 ± 1.8. The mean number of arcs for VMAT was 3.7 ± 1.1. The mean conformity index of VMAT (0.98 ± 0.14) was similar to that of IMRT (1.03 ± 0.13), both of which were significantly better than 3DCRT (1.35 ± 0.20; p = 0.005). The mean dose to lung was significantly higher for 3DCRT (11.9Gy ± 7.9) compared to IMRT (9.4Gy ± 5.4, p = 0.014) and VMAT (8.9Gy ± 4.5, p = 0.017). For the 3 females, the low dose regions in the ipsilateral breast for VMAT were generally less with VMAT. IMRT plans required 1427 ± 532 MU per fraction which was almost 4-fold higher than 3DCRT (313 ± 112, P = 0.005). Compared to IMRT, VMAT plans required 60 % less MU (570 ± 285, P = 0.005). For inoperable chest wall desmoid tumours, VMAT delivered equivalent target coverage when compared to IMRT but required 60 % less MU. Both VMAT and IMRT were superior to 3DCRT in terms of better PTV coverage and sparing of lung tissue

Hormone levels in radiotherapy treatment related fatigue

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Biswal, B.M.; Mallik, G.S.

2003-01-01

Radiotherapy is known to cause debilitating treatment related fatigue. Fatigue in general is a conglomeration of psychological, physical, hematological and unknown factors influencing the internal milieu of the cancer patient. Radiotherapy can add stress at the cellular and somatic level to aggravate further fatigue in cancer patients undergoing radiotherapy. Stress related hormones might be mediating in the development of fatigue. This is an ongoing prospective study to evaluate if the hormonal profile related to stress is influenced by radiotherapy treatment related fatigue. The study was conducted from September 2002 onwards in the division of Radiotherapy and Oncology of our Medical School. Previously untreated patients with histopathology proof of malignancy requiring external beam radiotherapy were considered for this study. Selection criteria were applied to exclude other causes of fatigue. Initial fatigue score was obtained using Pipers Fatigue Score questionnaire containing 23 questions, subsequently final fatigue score was obtained at the end of radiotherapy. Blood samples were obtained to estimate the levels of ACTH, TSH, HGH, and cortisol on the final assessment. The hormone levels were compared with resultant post radiotherapy fatigue score. At the time of reporting 50 patients were evaluable for the study. The total significant fatigue score was observed among 12 (24%) patients. The individual debilitating fatigue score were behavioral severity 14 (28%), affective meaning 14(28%), Sensory 13 (26%) and cognitive mood 10 (20%) respectively. From the analysis of hormonal profile, growth hormone level > 1 ng/mL and TSH <0.03 appears to be associated with high fatigue score (though statistically not significant); whereas there was no correlation with ACTH and serum cortisol level. In our prospective study severe radiotherapy treatment related fatigue was found among our patient population. Low levels of TSH and high levels of GH appear to be associated

Dosimetric comparison of field in field intensity-modulated radiotherapy technique with conformal radiotherapy techniques in breast cancer

International Nuclear Information System (INIS)

Ercan, T.; Alco, G.; Zengin, F.; Atilla, S.; Dincer, M.; Igdem, S.; Okkan, S.

2010-01-01

The aim of this study was to be able to implement the field-in-field intensity-modulated radiotherapy (FiF) technique in our daily practice for breast radiotherapy. To do this, we performed a dosimetric comparison. Treatment plans were produced for 20 consecutive patients. FiF plans and conformal radiotherapy (CRT) plans were compared for doses in the planning target volume (PTV), the dose homogeneity index (DHI), doses in irradiated soft tissue outside the target volume (SST), ipsilateral lung and heart doses for left breast irradiation, and the monitor unit counts (MU) required for treatment. Averaged values were compared using Student's t-test. With FiF, the DHI is improved 7.0% and 5.7%, respectively (P<0.0001) over the bilateral and lateral wedge CRT techniques. When the targeted volumes received 105% and 110% of the prescribed dose in the PTV were compared, significant decreases are found with the FiF technique. With the 105% dose, the SST, heart, and ipsilateral lung doses and the MU counts were also significantly lower with the FiF technique. The FiF technique, compared to CRT, for breast radiotherapy enables significantly better dose distribution in the PTV. Significant differences are also found for soft tissue volume, the ipsilateral lung dose, and the heart dose. Considering the decreased MUs needed for treatment, the FiF technique is preferred over tangential CRT. (author)

Conformation radiotherapy and conformal radiotherapy

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Morita, Kozo

1999-01-01

In order to coincide the high dose region to the target volume, the 'Conformation Radiotherapy Technique' using the multileaf collimator and the device for 'hollow-out technique' was developed by Prof. S. Takahashi in 1960. This technique can be classified a type of 2D-dynamic conformal RT techniques. By the clinical application of this technique, the late complications of the lens, the intestine and the urinary bladder after radiotherapy for the maxillary cancer and the cervical cancer decreased. Since 1980's the exact position and shape of the tumor and the surrounding normal tissues can be easily obtained by the tremendous development of the CT/MRI imaging technique. As a result, various kinds of new conformal techniques such as the 3D-CRT, the dose intensity modulation, the tomotherapy have been developed since the beginning of 1990'. Several 'dose escalation study with 2D-/3D conformal RT' is now under way to improve the treatment results. (author)

Combining Targeted Agents With Modern Radiotherapy in Soft Tissue Sarcomas

Science.gov (United States)

Wong, Philip; Houghton, Peter; Kirsch, David G.; Finkelstein, Steven E.; Monjazeb, Arta M.; Xu-Welliver, Meng; Dicker, Adam P.; Ahmed, Mansoor; Vikram, Bhadrasain; Teicher, Beverly A.; Coleman, C. Norman; Machtay, Mitchell; Curran, Walter J.

2014-01-01

Improved understanding of soft-tissue sarcoma (STS) biology has led to better distinction and subtyping of these diseases with the hope of exploiting the molecular characteristics of each subtype to develop appropriately targeted treatment regimens. In the care of patients with extremity STS, adjunctive radiation therapy (RT) is used to facilitate limb and function, preserving surgeries while maintaining five-year local control above 85%. In contrast, for STS originating from nonextremity anatomical sites, the rate of local recurrence is much higher (five-year local control is approximately 50%) and a major cause of death and morbidity in these patients. Incorporating novel technological advancements to administer accurate RT in combination with novel radiosensitizing agents could potentially improve local control and overall survival. RT efficacy in STS can be increased by modulating biological pathways such as angiogenesis, cell cycle regulation, cell survival signaling, and cancer-host immune interactions. Previous experiences, advancements, ongoing research, and current clinical trials combining RT with agents modulating one or more of the above pathways are reviewed. The standard clinical management of patients with STS with pretreatment biopsy, neoadjuvant treatment, and primary surgery provides an opportune disease model for interrogating translational hypotheses. The purpose of this review is to outline a strategic vision for clinical translation of preclinical findings and to identify appropriate targeted agents to combine with radiotherapy in the treatment of STS from different sites and/or different histology subtypes. PMID:25326640

Guidelines for primary radiotherapy of patients with prostate cancer

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Boehmer, Dirk; Maingon, Philippe; Poortmans, Philip; Baron, Marie-Helene; Miralbell, Raymond; Remouchamps, Vincent; Scrase, Christopher; Bossi, Alberto; Bolla, Michel

2006-01-01

Background and purposes: The appropriate application of 3-D conformal radiotherapy, intensity modulated radiotherapy or image guided radiotherapy for patients undergoing radiotherapy for prostate cancer requires a standardisation of target delineation as well as clinical quality assurance procedures. Patients and methods: Pathological and imaging studies provide valuable information on tumour extension. In addition, clinical investigations on patient positioning and immobilisation as well as treatment verification data offer an abundance of information. Results: Target volume definitions for different risk groups of prostate cancer patients based on pathological and imaging studies are provided. Available imaging modalities, patient positioning and treatment preparation studies as well as verification procedures are collected from literature studies. These studies are summarised and recommendations are given where appropriate. Conclusions: On behalf of the European Organisation for Research and Treatment of Cancer (EORTC) Radiation Oncology Group this article presents a common set of recommendations for external beam radiotherapy of patients with prostate cancer

Defining a radiotherapy target with positron emission tomography

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Black, Quinten C.; Grills, Inga S.; Kestin, Larry L.; Wong, Ching-Yee O.; Wong, John W.; Martinez, Alvaro A.; Yan Di

2004-01-01

Purpose: F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is now considered the most accurate clinical staging study for non-small-cell lung cancer (NSCLC) and is also important in the staging of multiple other malignancies. Gross tumor volume (GTV) definition for radiotherapy, however, is typically based entirely on computed tomographic data. We performed a series of phantom studies to determine an accurate and uniformly applicable method for defining a GTV with FDG-PET. Methods and materials: A model-based method was tested by a phantom study to determine a threshold, or unique cutoff of standardized uptake value based on body weight (standardized uptake value [SUV]) for FDG-PET based GTV definition. The degree to which mean target SUV, background FDG concentration, and target volume influenced that GTV definition were evaluated. A phantom was constructed consisting of a 9.0-L cylindrical tank. Glass spheres with volumes ranging from 12.2 to 291.0 cc were suspended within the tank, with a minimum separation of 4 cm between the edges of the spheres. The sphere volumes were selected based on the range of NSCLC patient tumor volumes seen in our clinic. The tank and spheres were filled with a variety of known concentrations of FDG in several experiments and then scanned using a General Electric Advance PET scanner. In the initial experiment, six spheres with identical volumes were filled with varying concentrations of FDG (mean SUV 1.85 ∼ 9.68) and suspended within a background bath of FDG at a similar concentration to that used in clinical practice (0.144 μCi/mL). The second experiment was identical to the first, but was performed at 0.144 and 0.036 μCi/mL background concentrations to determine the effect of background FDG concentration on sphere definition. In the third experiment, six spheres with volumes of 12.2 to 291.0 cc were filled with equal concentrations of FDG and suspended in a standard background FDG concentration of 0.144 �

Conformation radiotherapy with eccentric multi-leaves, (1)

International Nuclear Information System (INIS)

Obata, Yasunori; Sakuma, Sadayuki.

1986-01-01

In order to extend the application of the conformation radiotherapy, the eccentric multi-leaves are equipped with the linear accelerator. The information of the position of the collimators and the dose distribution of the eccentric conformation radiotherapy are calculated by the improved algorism of the treatment planning system. In simple cases, the dose distributions for the distant region from the rotational center are measured and compared with the calculated values. Both distributions are well coincided with the error of about 5 % in the high dose region and 10 % in the low dose region. In eccentric conformation radiotherapy, it is difficult to deliver the planned dose to the lesion. The dose increases with the distance of the target area from the rotational center. And the measured value and the calculated value are well coincided with 1 % error. So after getting the dose ratio of the rotational center to the target area, the calculated dose can be delivered to the rotational center. The advantages of the eccentric conformation radiotherapy are a good coincidence of target area and treated area, a partial shielding and a hollow out technique without absorber. The limitation of the movement of the collimator from center is 5 cm at 1 m SCD. (author)

EGFR-targeted anti-cancer drugs in radiotherapy: Preclinical evaluation of mechanisms

International Nuclear Information System (INIS)

Baumann, Michael; Krause, Mechthild; Dikomey, Ekkehard; Dittmann, Klaus; Doerr, Wolfgang; Kasten-Pisula, Ulla; Rodemann, H. Peter

2007-01-01

Preclinical and clinical results indicate that the EGFR can mediate radioresistance in different solid human tumours. Combination of radiotherapy and EGFR inhibitors can improve local tumour control compared to irradiation alone and has been introduced into clinical radiotherapy practice. So far several mechanisms have been identified in preclinical studies to contribute to improved local tumour control after radiation combined with EGFR inhibitors. These include direct kill of cancer stem cells by EGFR inhibitors, cellular radiosensitization through modified signal transduction, inhibition of repair of DNA damage, reduced repopulation and improved reoxygenation during fractionated radiotherapy. Effects and mechanisms may differ for different classes of EGFR inhibitors, for different tumours and for normal tissues. The mechanisms underlying this heterogeneity are currently poorly understood, and predictive assays are not available yet. Importantly, mechanisms and predictors for the combined effects of radiation with EGFR inhibitors appear to be considerably different to those for application of EGFR inhibitors alone or in combination with chemotherapy. Therefore to further evaluate the efficacy and mechanisms of EGFR-inhibition in combined treatments, radiotherapy-specific preclinical research strategies, which include in vivo experiments using local tumour control as an endpoint, as well as animal studies on normal tissue toxicity are needed

Internal dosimetry through GATE simulations of preclinical radiotherapy using a melanin-targeting ligand

International Nuclear Information System (INIS)

Perrot, Y; Donnarieix, D; Maigne, L; Degoul, F; Auzeloux, P; Bonnet, M; Cachin, F; Chezal, J M; Labarre, P; Moins, N; Papon, J; Rbah-Vidal, L; Vidal, A; Miot-Noirault, E

2014-01-01

The GATE Monte Carlo simulation platform based on the Geant4 toolkit is under constant improvement for dosimetric calculations. In this study, we explore its use for the dosimetry of the preclinical targeted radiotherapy of melanoma using a new specific melanin-targeting radiotracer labeled with iodine 131. Calculated absorbed fractions and S values for spheres and murine models (digital and CT-scan-based mouse phantoms) are compared between GATE and EGSnrc Monte Carlo codes considering monoenergetic electrons and the detailed energy spectrum of iodine 131. The behavior of Geant4 standard and low energy models is also tested. Following the different authors’ guidelines concerning the parameterization of electron physics models, this study demonstrates an agreement of 1.2% and 1.5% with EGSnrc, respectively, for the calculation of S values for small spheres and mouse phantoms. S values calculated with GATE are then used to compute the dose distribution in organs of interest using the activity distribution in mouse phantoms. This study gives the dosimetric data required for the translation of the new treatment to the clinic. (paper)

Otologic disorders following radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Wakisaka, Hiroyuki; Hyodo, Masamitsu; Motoyoshi, Kazumi; Yamada, Hiroyuki

2007-01-01

Radiotherapy is widely accepted as the first choice for nasopharyngeal carcinoma. Delayed otitis of both external and middle ears is sometimes seen as a complication after radiotherapy for head and neck cancer, especially for nasopharyngeal carcinoma. They are usually hard to manage and some produces cochlear damages, finally resulting in a sensorineural hearing loss. However, these otologic disorders are tends to be overlooked, because physicians pay less attention to them than the concerning for cancer recurrence. Therefore, studies on the otologic disorders following radiotherapy are lacking. In this study, we analyzed 24 nasopharyngeal carcinoma cases retrospectively to clarify the incidence of otologic disorders induced by radiotherapy. (author)

[Novel irradiation techniques in the treatment of solid tumours. Radiotherapy for metastases].

Science.gov (United States)

Mayer, Arpád; Póti, Zsuzsa

2014-02-23

Novel developments in percutaneous radiotherapy, such as positron emission tomography/computed tomography, adaptive radiation planning, intensity modulation radiotherapy and intensity modulated arc therapy (RapidArc), as well as the newer generation of image control (cone-beam computed tomography) and image guided radiotherapy ensure increased dosages of planning target volume and clinical target volume of solid tumours without damaging surrounding tissues and providing maximal protection. By raising the dosages of planned target volume and clinical target volume, these novel technical developments have created new indications in the treatment of solid tumours. With the aid of the cone-beam computed tomography and image guided radiotherapy the organ metastasis (lung, liver, spinal cord) and the primary tumour can be treated safety and effectively. Hypofractionation, dose escalation and the use of stereotactic devices can probably decrease radiation damage. The authors review the most common forms of evidence-based fractionation schemes used in irradiation therapy.

Rotational radiotherapy for prostate cancer in clinical practice

DEFF Research Database (Denmark)

Aznar, Marianne C; Petersen, Peter Meidahl; Logadottir, Ashildur

2010-01-01

Radiotherapy is the standard treatment in locally advanced prostate cancer. The latest technological improvement is modulated rotational radiotherapy, where one single rotation of the treatment machine is used to conform the dose delivery to the target and spare organs at risk, requiring less than...

Quality Management in Radiotherapy. Chapter 19

International Nuclear Information System (INIS)

Scalliet, P.

2017-01-01

Soon after the discovery of X rays and natural radioactivity, the therapeutic use of ionizing radiation grew into what has today become an important oncological specialty, with unmatched cost–benefit features. Radiotherapy is an inexpensive solution to many cancers; it is a reproducible technique with fundamentals that rely both on a large set of evidence based medical data and on high technology equipment that has benefited from the digital revolution in the second half of the twentieth century. One characteristic of radiotherapy is its narrow therapeutic window, with cure being never very far from injury. Therefore, radiotherapy administration requires great accuracy in target volume definition and dose control. Modest underdosage leads to the recurrence of cancer, while overdosage leads to unacceptable toxicity. While more sophisticated treatment techniques have emerged recently (intensity modulation, image guidance, hadrons), equally sophisticated means to control the actual delivery of radiotherapy have been developed. Better control of dose delivery allows for better delineation between target tissue exposed to high doses and normal tissue shielded to the maximum, with steep dose gradients sometimes over a few millimetres. This, in turn, requires better volume definition and better control of patient positioning.

Approaches to radiotherapy in metastatic spinal cord compression.

Science.gov (United States)

Suppl, Morten Hiul

2018-04-01

Metastatic spinal cord compression is caused by the progression of metastatic lesions within the vicinity of the spinal cord. The consequences are very severe with loss of neurological function and severe pain. The standard treatment is surgical intervention followed by radiotherapy or radiotherapy alone. However, the majority of patients are treated with radiotherapy only due to contraindications to surgery and technical inoperability. Stereotactic body radiotherapy is a technology to deliver higher radiation dose to the radiotherapy target with the use of spatial coordinates. This modality has shown positive results in treating lesions in brain and lungs. Hence, it could prove beneficial in metastatic spinal cord compression. We designed and planned a trial to investigate this method in patients with metastatic spinal cord compression. The method was usable but the trial was stopped prematurely due to low accrual that made comparison with surgery impossible. Low accrual is a known problem for trials evaluating new approaches in radiotherapy. Target definition in radiotherapy of metastatic spinal cord compression is defined by patient history, examination and imaging. Functional imaging could provide information to guide target definition with the sparring of normal tissue e.g. spinal cord and hematopoietic tissue of the bone marrow. In future trials this may be used for dose escalation of spinal metastases. The trial showed that PET/MRI was feasible in this group of patients but did not change the radiotherapy target in the included patients. Neurological outcome is similar irrespective of course length and therefore single fraction radiotherapy is recommended for the majority of patients. In-field recurrence is a risk factor of both short and long fractionation schemes and re-irradiation have the potential risk of radiation-induced myelopathy. In a retrospective study of re-irradiation, we investigated the incidence of radiation-induced myelopathy. In our study

Long-term effects of radiotherapy for acromegaly on circulating prolactin

International Nuclear Information System (INIS)

Ciccarelli, E.; Corsello, S.M.; Besser, G.M.; Wass, J.A.H.; Plowman, P.N.; Jones, A.E.; Touzel, R.; Rees, L.H.

1989-01-01

In 61 acromegalic patients, serum PRL was assessed (off medical treatment) before and 2 to 12 (mean 6 p years after external beam radiotherapy. Before radiotherapy elevated PRL levels were present in 22 of 35 males (63%) and 12 of 26 females (46%) and were above 1000 mU/l in 11 males and 5 females. When studied for up to 5 years after radiotherapy, 22 or 23 (96%) patients who had not had surgery and who had normal PRL preradiotherapy showed an increased PRL level and this was also seen in 17 or 27 (63%) who had hyperprolactinaemic initially. In contrast, 10 of 27 patients (37%) who had elevated pre-radiotherapy levels (all greater than 1000 mU/l) had a reduction in PRL values after radiotherapy. In all 11 patients who underwent surgery before radiotherapy, an increase in PRL was seen after radiotherapy. In the 21 patients followed for 10-12 years, the peak PRL value occurred 1-6 years after radiotherapy. After this, a progressive reduction of PRL to normal was seen. Normal levels were reached 4 to 10 years after radiotherapy. No correlation was found between pretreatment PRL values and final GH values in the whole group, nor between changes in PRL and the development of Impaired ACTH or TSH secretion. Thus, different patterns of PRL behaviour suggest that radiotherapy treatment may either produce hyperprolactinemia from mild hypothalamic damage or ablate PRL secreting cells if they were present in the tumour before treatment. These changes do not predict final GH results or the development of hypopituitarism after radiotherapy. (author)

Long-term effects of radiotherapy for acromegaly on circulating prolactin

Energy Technology Data Exchange (ETDEWEB)

Ciccarelli, E.; Corsello, S.M.; Besser, G.M.; Wass, J.A.H. (Department of Endocrinology, St. Bartholomew' s Hospital, West Smithfield, London (UK)); Plowman, P.N.; Jones, A.E. (Department of Radiotherapy, St. Bartholomew' s Hospital, West Smithfield, London (UK)); Touzel, R.; Rees, L.H. (Department of Chemical Endocrinology, St. Bartholomew' s Hospital, West Smithfield, London (UK))

1989-01-01

In 61 acromegalic patients, serum PRL was assessed (off medical treatment) before and 2 to 12 (mean 6 p) years after external beam radiotherapy. Before radiotherapy elevated PRL levels were present in 22 of 35 males (63%) and 12 of 26 females (46%) and were above 1000 mU/l in 11 males and 5 females. When studied for up to 5 years after radiotherapy, 22 or 23 (96%) patients who had not had surgery and who had normal PRL preradiotherapy showed an increased PRL level and this was also seen in 17 or 27 (63%) who had hyperprolactinaemic initially. In contrast, 10 of 27 patients (37%) who had elevated pre-radiotherapy levels (all greater than 1000 mU/l) had a reduction in PRL values after radiotherapy. In all 11 patients who underwent surgery before radiotherapy, an increase in PRL was seen after radiotherapy. In the 21 patients followed for 10--12 years, the peak PRL value occurred 1--6 years after radiotherapy. After this, a progressive reduction of PRL to normal was seen. Normal levels were reached 4 to 10 years after radiotherapy. No correlation was found between pretreatment PRL values and final GH values in the whole group, nor between changes in PRL and the development of Impaired ACTH or TSH secretion. Thus, different patterns of PRL behaviour suggest that radiotherapy treatment may either produce hyperprolactinemia from mild hypothalamic damage or ablate PRL secreting cells if they were present in the tumour before treatment. These changes do not predict final GH results or the development of hypopituitarism after radiotherapy. (author).

Targeted Radionuclide Therapy

Directory of Open Access Journals (Sweden)

David Cheng

2011-10-01

Full Text Available Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

Targeted Radionuclide Therapy

Energy Technology Data Exchange (ETDEWEB)

Ersahin, Devrim, E-mail: devrimersahin@yahoo.com; Doddamane, Indukala; Cheng, David [Department of Diagnostic Radiology, School of Medicine, Yale University, 333 Cedar St., New Haven, CT 06520 (United States)

2011-10-11

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.

Targeted Radionuclide Therapy

International Nuclear Information System (INIS)

Ersahin, Devrim; Doddamane, Indukala; Cheng, David

2011-01-01

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose

Moving toward multi-dimensional radiotherapy and the role of radiobiology

International Nuclear Information System (INIS)

Oita, Masataka; Uto, Yoshihiro; Aoyama, Hideki

2014-01-01

Recent radiotherapy for cancer treatment enable the high-precision irradiation to the target under the computed image guidance. Developments of such radiotherapy has played large role in the improved strategy of cancer treatments. In addition, the molecular mechanistic studies related to proliferations of cancer cell contribute the multidisciplinary fields of clinical radiotherapies. Therefore, the combination of the image guidance and molecular targeting of cancer cells make it possible for individualized cancer treatment. Especially, the use of particle beam or boron neutron capture therapy (BNCT) has been spotlighted, and installations of such devices are planned widely. As the progress and collaborations of radiation biology and engineering physics, establishment of a new style of radiotherapy becomes available in post-genome era. In 2010s, the hi-tech machines controlling the spaciotemporal radiotherapy become in practice. Although, there still remains to be improved, e.g., more precise prediction of radiosensitivity or growth of individual tumors, and adverse outcomes after treatments, multi-dimensional optimizations of the individualized irradiations based on the molecular radiation biologies and medical physics are important for further development of radiotherapy. (author)

Telemedicine in radiotherapy treatment planning: requirements and applications

International Nuclear Information System (INIS)

Olsen, D.R.; Bruland, O.S.; Davis, B.J.

2000-01-01

Telemedicine facilitates decentralized radiotherapy services by allowing remote treatment planning and quality assurance of treatment delivery. A prerequisite is digital storage of relevant data and an efficient and reliable telecommunication system between satellite units and the main radiotherapy clinic. The requirements of a telemedicine system in radiotherapy is influenced by the level of support needed. In this paper we differentiate between three categories of telemedicine support in radiotherapy. Level 1 features video conferencing and display of radiotherapy images and dose plans. Level 2 involves replication of selected data from the radiotherapy database - facilitating remote treatment planning and evaluation. Level 3 includes real-time, remote operations, e.g. target volume delineation and treatment planning performed by the team at the satellite unit under supervision and guidance from more experienced colleagues at the main clinic. (author)

Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System

Science.gov (United States)

Court, Laurence E.; Kisling, Kelly; McCarroll, Rachel; Zhang, Lifei; Yang, Jinzhong; Simonds, Hannah; du Toit, Monique; Trauernicht, Chris; Burger, Hester; Parkes, Jeannette; Mejia, Mike; Bojador, Maureen; Balter, Peter; Branco, Daniela; Steinmann, Angela; Baltz, Garrett; Gay, Skylar; Anderson, Brian; Cardenas, Carlos; Jhingran, Anuja; Shaitelman, Simona; Bogler, Oliver; Schmeller, Kathleen; Followill, David; Howell, Rebecca; Nelson, Christopher; Peterson, Christine; Beadle, Beth

2018-01-01

The Radiation Planning Assistant (RPA) is a system developed for the fully automated creation of radiotherapy treatment plans, including volume-modulated arc therapy (VMAT) plans for patients with head/neck cancer and 4-field box plans for patients with cervical cancer. It is a combination of specially developed in-house software that uses an application programming interface to communicate with a commercial radiotherapy treatment planning system. It also interfaces with a commercial secondary dose verification software. The necessary inputs to the system are a Treatment Plan Order, approved by the radiation oncologist, and a simulation computed tomography (CT) image, approved by the radiographer. The RPA then generates a complete radiotherapy treatment plan. For the cervical cancer treatment plans, no additional user intervention is necessary until the plan is complete. For head/neck treatment plans, after the normal tissue and some of the target structures are automatically delineated on the CT image, the radiation oncologist must review the contours, making edits if necessary. They also delineate the gross tumor volume. The RPA then completes the treatment planning process, creating a VMAT plan. Finally, the completed plan must be reviewed by qualified clinical staff. PMID:29708544

Secondary effects of radiotherapy on the orofacial sphere

International Nuclear Information System (INIS)

Guillaume, Nicolas

2012-01-01

The objective of this research is to determine the role of the dental surgeon in the taking into care of patients treated by head and neck radiotherapy. It also aims at giving information to the patient on secondary effects which radiotherapy may induce, and at determining which therapeutic behaviour to adopt to prevent or at least mitigate the appearance of complications. The author first presents some generalities on radiotherapy: presentation of upper aero-digestive tract cancers (surgery, radiotherapy, and chemotherapy), description of the different radiotherapy techniques (external radiotherapy, brachytherapy), discussion of factors influencing local secondary effects of radiotherapy. The second part addresses the specific case of early orofacial secondary effects, discusses their origin, clinic signs and prevention means: cutaneous effect, mucositis, xerostomia, candidiasis, taste disorders, relationship between early local reactions and anti-tumour treatment efficiency. The third part addresses late orofacial secondary effects: cervix sclerosis, limitation of mouth opening, dental effects, periodontal diseases, osteoradionecrosis. The last part discusses the evolution of radiotherapy: intensity modulated conformational radiotherapy, targeted therapeutics [fr

Real-time dynamic MLC tracking for inversely optimized arc radiotherapy

DEFF Research Database (Denmark)

Falk, Marianne; af Rosenschöld, Per Munck; Keall, Paul

2010-01-01

Motion compensation with MLC tracking was tested for inversely optimized arc radiotherapy with special attention to the impact of the size of the target displacements and the angle of the leaf trajectory.......Motion compensation with MLC tracking was tested for inversely optimized arc radiotherapy with special attention to the impact of the size of the target displacements and the angle of the leaf trajectory....

Carbon-ion radiotherapy for marginal lymph node recurrences of cervical cancer after definitive radiotherapy: a case report

International Nuclear Information System (INIS)

Tamaki, Tomoaki; Nakano, Takashi; Ohno, Tatsuya; Kiyohara, Hiroki; Noda, Shin-ei; Ohkubo, Yu; Ando, Ken; Wakatsuki, Masaru; Kato, Shingo; Kamada, Tadashi

2013-01-01

Recurrences of cervical cancer after definitive radiotherapy often occur at common iliac or para-aortic lymph nodes as marginal lymph node recurrences. Patients with these recurrences have a chance of long-term survival by optimal re-treatment with radiotherapy. However, the re-irradiation often overlaps the initial and the secondary radiotherapy fields and can result in increased normal tissue toxicities in the bowels or the stomach. Carbon-ion radiotherapy, a form of particle beam radiotherapy using accelerated carbon ions, offers more conformal and sharp dose distribution than X-ray radiotherapy. Therefore, this approach enables the delivery of high radiation doses to the target while sparing its surrounding normal tissues. Marginal lymph node recurrences in common iliac lymph nodes after radiotherapy were treated successfully by carbon-ion radiotherapy in two patients. These two patients were initially treated with a combination of external beam radiotherapy and intracavitary and interstitial brachytherapy. However, the diseases recurred in the lymph nodes near the border of the initial radiotherapy fields after 22 months and 23 months. Because re-irradiation with X-ray radiotherapy may deliver high doses to a section of the bowels, carbon-ion radiotherapy was selected to treat the lymph node recurrences. A total dose of 48 Gy (RBE) in 12 fractions over 3 weeks was given to the lymph node recurrences, and the tumors disappeared completely with no severe acute toxicities. The two patients showed no evidence of disease for 75 months and 63 months after the initial radiotherapy and for 50 months and 37 months after the carbon-ion radiotherapy, respectively. No severe late adverse effects are observed in these patients. The two presented cases suggest that the highly conformal dose distribution of carbon-ion radiotherapy may be beneficial in the treatment of marginal lymph node recurrences after radiotherapy. In addition, the higher biological effect of carbon

Individualized planning target volumes for intrafraction motion during hypofractionated intensity-modulated radiotherapy boost for prostate cancer

International Nuclear Information System (INIS)

Cheung, Patrick; Sixel, Katharina; Morton, Gerard; Loblaw, D. Andrew; Tirona, Romeo; Pang, Geordi; Choo, Richard; Szumacher, Ewa; DeBoer, Gerrit; Pignol, Jean-Philippe

2005-01-01

Purpose: The objective of the study was to access toxicities of delivering a hypofractionated intensity-modulated radiotherapy (IMRT) boost with individualized intrafraction planning target volume (PTV) margins and daily online correction for prostate position. Methods and materials: Phase I involved delivering 42 Gy in 21 fractions using three-dimensional conformal radiotherapy, followed by a Phase II IMRT boost of 30 Gy in 10 fractions. Digital fluoroscopy was used to measure respiratory-induced motion of implanted fiducial markers within the prostate. Electronic portal images were taken of fiducial marker positions before and after each fraction of radiotherapy during the first 9 days of treatment to calculate intrafraction motion. A uniform 10-mm PTV margin was used for the first phase of treatment. PTV margins for Phase II were patient-specific and were calculated from the respiratory and intrafraction motion data obtained from Phase I. The IMRT boost was delivered with daily online correction of fiducial marker position. Acute toxicity was measured using National Cancer Institute Common Toxicity Criteria, version 2.0. Results: In 33 patients who had completed treatment, the average PTV margin used during the hypofractionated IMRT boost was 3 mm in the lateral direction, 3 mm in the superior-inferior direction, and 4 mm in the anteroposterior direction. No patients developed acute Grade 3 rectal toxicity. Three patients developed acute Grade 3 urinary frequency and urgency. Conclusions: PTV margins can be reduced significantly with daily online correction of prostate position. Delivering a hypofractionated boost with this high-precision IMRT technique resulted in acceptable acute toxicity

The functional imaging in target volume delineation of radiotherapy planning for gliomas

International Nuclear Information System (INIS)

Huang Jingxiong; Wu Hua

2007-01-01

Radiotherapy is one of important treatments for glioma. Functional imaging, such as PET, SPECT and MRI, may provide more valuable information not only in display of the evasion extent of glioma but also in demonstration of some biological characteristics of the tumor, such as perfusion, metabolism, hypoxia or proliferation. Thus it may play a role in making an individualized and more exact radiotherapy planning. (authors)

X-ray volume imaging in bladder radiotherapy verification

International Nuclear Information System (INIS)

Henry, Ann M.; Stratford, Julia; McCarthy, Claire; Davies, Julie; Sykes, Jonathan R.; Amer, Ali; Marchant, Tom; Cowan, Richard; Wylie, James; Logue, John; Livsey, Jacqueline; Khoo, Vincent S.; Moore, Chris; Price, Pat

2006-01-01

Purpose: To assess the clinical utility of X-ray volume imaging (XVI) for verification of bladder radiotherapy and to quantify geometric error in bladder radiotherapy delivery. Methods and Materials: Twenty subjects undergoing conformal bladder radiotherapy were recruited. X-ray volume images and electronic portal images (EPIs) were acquired for the first 5 fractions and then once weekly. X-ray volume images were co-registered with the planning computed tomography scan and clinical target volume coverage assessed in three dimensions (3D). Interfraction bladder volume change was described by quantifying changes in bladder volume with time. Bony setup errors were compared from both XVI and EPI. Results: The bladder boundary was clearly visible on coronal XVI views in nearly all images, allowing accurate 3D treatment verification. In 93.5% of imaged fractions, the clinical target volume was within the planning target volume. Most subjects displayed consistent bladder volumes, but 25% displayed changes that could be predicted from the first three XVIs. Bony setup errors were similar whether calculated from XVI or EPI. Conclusions: Coronal XVI can be used to verify 3D bladder radiotherapy delivery. Image-guided interventions to reduce geographic miss and normal tissue toxicity are feasible with this technology

Arterial disease after radiotherapy

International Nuclear Information System (INIS)

Bigot, J.M.; Mathieu, D.; Reizine, D.

1983-01-01

Disease of the large arterial vessels is a relatively unknown complication of radiotherapy. However, it should be considered in the same manner as the other complications of irradiation when a tumour recurrence is suspected. The experimental studies of Kirkpatrick and Konings, demonstrating the synergy between irradiation and hypercholesterolemia in the precocity and gravity of vascular complications are recalled. The different localisations reported in the litterature are discussed: coronary, pulmonary, thoracic aorta, supra aortic, renal, digestive and ilio-femoral arteries. Finally, the difficulty of diagnosis of post-radiotherapy without clinical, radiological or anatomopathological confirmation, is underlined [fr

Targeted radiotherapy with 177 Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

International Nuclear Information System (INIS)

Murphy, M. A de; Pedraza L, M.; Rodriguez C, J.; Ferro F, G.; Murphy S, E.

2006-01-01

Malignant pancreas tumours induced in athymic mice are a good model for targeted radiotherapy. The objective of this research was to estimate pancreatic tumour absorbed radiation doses and to evaluate 177 Lu-DOTA-TATE as a therapeutic radiopharmaceutical that could be used in humans. AR42J murine pancreas cancer cells, which over-express somatostatin receptors, were injected in athymic mice and 20 days later the mean tumour size was 3.08 square cm (n=3). A mean of 86.3 MBq 177 Lu-DOTA-TATE, was injected in a tail vein and 19 days after therapy the size of the tumours was 0.81 square cm. There was a partial relapse and after 16 days, when sacrificed, the mean tumour size was 8.28 cubic cm. An epithelial and sarcoma mixed tumour in the kidney of one treated mouse was found. The tumour of the control mouse was 8.61 cubic cm when sacrificed 14 days after tumour induction. Radiotherapy estimates to the tumours was 35.9-39.7 Gy and the tumours might have been completely reduced with a second therapy dose. These preliminary studies justify further therapeutic and dosimetry estimations to ensure that Lu- 177 -DOTA-TATE will act as expected in man, considering kidney radiation. (Author)

Dosimetric Feasibility of Hypofractionated Proton Radiotherapy for Neoadjuvant Pancreatic Cancer Treatment

International Nuclear Information System (INIS)

Kozak, Kevin R.; Kachnic, Lisa A.; Adams, Judith C; Crowley, Elizabeth M.; Alexander, Brian M.; Mamon, Harvey J.; Fernandez-Del Castillo, Carlos; Ryan, David P.; DeLaney, Thomas F.; Hong, Theodore S.

2007-01-01

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

A multi-modality concept for radiotherapy planning with imaging techniques

International Nuclear Information System (INIS)

Schultze, J.

1993-01-01

The reported multi-modality concept of radiotherapy planning in the LAN can be realised in any hospital with standard equipment, although in some cases by way of auxiliary configurations. A software is currently developed as a tool for reducing the entire planning work. The heart of any radiotherapy planning is the therapy simulator, which has to be abreast with the requirements of modern radiotherapy. Integration of tomograpy, digitalisation, and electronic data processing has added important modalities to therapy planning which allow more precise target volume definition, and better biophysical planning. This is what is needed in order to achieve well differentiated radiotherapy for treatment of the manifold tumors, and the quality standards expected by the supervisory quality assurance regime and the population. At present, the CT data still are transferred indirect, on storage media, to the EDP processing system of the radiotherapy planning system. Based on the tomographic slices given by the imaging data, the contours and technical problem solutions are derived automatically, either for multi-field radiotherapy or moving field irradiation, depending on the anatomy or the targets to be protected from ionizing radiation. (orig./VHE) [de

Stage report of the national radiotherapy survey committee May 2009; Rapport d'etape du Comite National de suivi de la radiotherapie mai 2009

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

This report proposes an assessment of the impact of the national radiotherapy measures present in the road map (November 2007 - March 2009) and describes the creation of a national support unit to manage the operating difficulties of 27 radiotherapy centres. It comments how a transition period between 2009 and 2011 must accompany radiotherapy before the implementation of opposable agreement criteria in 2011, notably through an improvement of recruitment, a support to cooperation between radiotherapy centres, the implementation of a radio-vigilance unit. Finally, it briefly discusses how to prepare the 2011-2013 period.

Implementation of a risk assessment tool based on a probabilistic safety assessment developed for radiotherapy practices

International Nuclear Information System (INIS)

Paz, A.; Godinez, V.; Lopez, R.

2010-10-01

The present work describes the implementation process and main results of the risk assessment to the radiotherapy practices with Linear Accelerators (Linac), with cobalt 60, and with brachytherapy. These evaluations were made throughout the risk assessment tool for radiotherapy practices SEVRRA (risk evaluation system for radiotherapy), developed at the Mexican National Commission in Nuclear Safety and Safeguards derived from the outcome obtained with the Probabilistic Safety Analysis developed at the Ibero-American Regulators Forum for these radiotherapy facilities. The methodology used is supported by risk matrices method, a mathematical tool that estimates the risk to the patient, radiation workers and public from mechanical failures, mis calibration of the devices, human mistakes, and so. The initiating events are defined as those undesirable events that, together with other failures, can produce a delivery of an over-dose or an under-dose of the medical prescribed dose, to the planned target volume, or a significant dose to non prescribed human organs. Initiating events frequency and reducer of its frequency (actions intended to avoid the accident) are estimated as well as robustness of barriers to those actions, such as mechanical switches, which detect and prevent the accident from occurring. The spectrum of the consequences is parameterized, and the actions performed to reduce the consequences are identified. Based on this analysis, a software tool was developed in order to simplify the evaluations to radiotherapy installations and it has been applied as a first step forward to some Mexican installations, as part of a national implementation process, the final goal is evaluation of all Mexican facilities in the near future. The main target and benefits of the SEVRRA implementation are presented in this paper. (Author)

Implementation of a risk assessment tool based on a probabilistic safety assessment developed for radiotherapy practices

Energy Technology Data Exchange (ETDEWEB)

Paz, A.; Godinez, V.; Lopez, R., E-mail: abpaz@cnsns.gob.m [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

2010-10-15

The present work describes the implementation process and main results of the risk assessment to the radiotherapy practices with Linear Accelerators (Linac), with cobalt 60, and with brachytherapy. These evaluations were made throughout the risk assessment tool for radiotherapy practices SEVRRA (risk evaluation system for radiotherapy), developed at the Mexican National Commission in Nuclear Safety and Safeguards derived from the outcome obtained with the Probabilistic Safety Analysis developed at the Ibero-American Regulators Forum for these radiotherapy facilities. The methodology used is supported by risk matrices method, a mathematical tool that estimates the risk to the patient, radiation workers and public from mechanical failures, mis calibration of the devices, human mistakes, and so. The initiating events are defined as those undesirable events that, together with other failures, can produce a delivery of an over-dose or an under-dose of the medical prescribed dose, to the planned target volume, or a significant dose to non prescribed human organs. Initiating events frequency and reducer of its frequency (actions intended to avoid the accident) are estimated as well as robustness of barriers to those actions, such as mechanical switches, which detect and prevent the accident from occurring. The spectrum of the consequences is parameterized, and the actions performed to reduce the consequences are identified. Based on this analysis, a software tool was developed in order to simplify the evaluations to radiotherapy installations and it has been applied as a first step forward to some Mexican installations, as part of a national implementation process, the final goal is evaluation of all Mexican facilities in the near future. The main target and benefits of the SEVRRA implementation are presented in this paper. (Author)

Patient Radiation Protection in Radiotherapy

International Nuclear Information System (INIS)

Hegazy, M.

2010-01-01

The Role of Radiotherapy is treatment modalities for cancer which is generally assumed that 50 to 60% of cancer patients will benefit from radiotherapy. It constitutes a peaceful application of ionizing radiation and an essential part of cancer management. The two aims of radiation protection Prevention is of deterministic effect and Reduction of the probability of stochastic effects. The Shielding fundamentals is to limit radiation exposure of staff, patients, visitors and the public to acceptable levels it also optimize protection of patients, staff and the public. Diagnosis is important for target design and the dose required for cure or palliation while Simulator is often used twice in the radiotherapy process where Patient data acquisition - target localization, contours, outlines and Verification. The Prescription is the responsibility of individual clinicians, depending on the patient’s condition, equipment available, experience and training. An ultimate check of the actual treatment given can only be made by using in vivo dosimetry. Treatment records must be kept of all relevant aspects of the treatment – including Session and Summary Record information, Records all treatment parameters, Dose Calculations and Dose Measurements

Head and neck cancers: clinical benefits of three-dimensional conformal radiotherapy and of intensity-modulated radiotherapy

International Nuclear Information System (INIS)

Giraud, P.; Jaulerry, C.; Brunin, F.; Zefkili, S.; Helfre, S.; Chauvet, I.; Rosenwald, J.C.; Cosset, J.M.

2002-01-01

The conformal radiotherapy approach, three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT), is based on modern imaging modalities, efficient 3-D treatment planning systems, sophisticated immobilization systems and rigorous quality assurance and treatment verification. The central objective of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of normal tissues. These techniques would then allow further tumor dose escalation. Head-and-neck tumors are some of the most attractive localizations to test conformal radiotherapy. They combine ballistic difficulties due to particularly complex shapes (nasopharynx, ethmoid) and problems due to the number and low tolerance of neighbouring organs like parotids, eyes, brainstem and spinal cord. The therapeutic irradiation of head-and-neck tumors thus remains a challenge for the radiation oncologist. Conformal radiotherapy does have a significant potential for improving local control and reducing toxicity when compared to standard radiotherapy. However, in the absence of prospective randomized trials, it is somewhat difficult at present to evaluate the real benefits drawn from 3DCRT and IMRT. The published clinical reports on the use of conformal radiotherapy are essentially dealing with dosimetric comparisons on relatively small numbers of patients. Recently, a few publications have emphasized the clinical experience several precursor teams with a suitable follow-up. This paper describes the current state-of-the-art of 3DCRT and IMRT in order to evaluate the impact of these techniques on head-and-neck cancers irradiation. (authors)

Australian and New Zealand Faculty of Radiation Oncology Genito-Urinary Group: 2011 consensus guidelines for curative radiotherapy for urothelial carcinoma of the bladder

International Nuclear Information System (INIS)

Hindson, Benjamin R.; Turner, Sandra L.; Millar, Jeremy L.

2012-01-01

Curative radiotherapy, with or without concurrent chemotherapy, is recognized as a standard treatment option for muscle-invasive bladder cancer. It is commonly used for two distinct groups of patients: either for those medically unfit for surgery, or as part of a 'bladder preserving' management plan incorporating the possibility of salvage cystectomy. However, in both situations, the approach to radiotherapy varies widely around the world. The Australian and New Zealand Faculty of Radiation Oncology Genito-Urinary Group recognised a need to develop consistent, evidence-based guidelines for patient selection and radiotherapy technique in the delivery of curative radiotherapy. Following a workshop convened in May 2009, a working party collated opinions and conducted a wide literature appraisal linking each recommendation with the best available evidence. This process was subject to ongoing re-presentation to the Faculty of Radiation Oncology Genito-Urinary Group members prior to final endorsement. These Guidelines include patient selection, radiation target delineation, dose and fractionation schedules, normal tissue constraints and investigational techniques. Particular emphasis is given to the rationale for the target volumes described. These Guidelines provide a consensus-based framework for the delivery of curative radiotherapy for muscle-invasive bladder cancer. Widespread input from radiation oncologists treating bladder cancer ensures that these techniques are feasible in practice. We recommend these Guidelines be adopted widely in order to encourage a uniformly high standard of radiotherapy in this setting, and to allow for better comparison of outcomes.

Targeted radiotherapy of osteosarcoma using 153Sm-EDTMP. A new promising approach

International Nuclear Information System (INIS)

Bruland, Oe.S.; Skretting, A.; Solheim, Oe.P.; Aas, M.

1996-01-01

We report a case where targeted radionuclide therapy using 153 Sm-EDTMP gave substantial palliative effect. A 35-year-old male with a primary osteosarcoma located in the first lumbar vertebra relapsed with progressive back pain after conventional treatment modalities had failed. He became bedridden, and developed paraparesis and impaired bladder function. On a diagnostic bone-scan intense radioactivity was localized in the tumor. He therefore was given 153 Sm-EDTMP treatment twice, 8 weeks apart, 35 and 32 MBq/kg body weight respectively. After a few days the pain was significantly relieved and by the second radionuclide treatment the pareses subsided. For six months he was able to be up and about without any neurological signs or detectable metastases. Eventually, however, he experienced increasing local pain, developed paraparesis, was re-operated but died 4 months later. The dramatic transient improvement observed in this case warrants further exploration using 153 Sm-EDTMP as a boost technique, supplementary to conventiontal external radiotherapy. (orig.)

A Comparative Dosimetric Study of Adjuvant 3D Conformal Radiotherapy for Operable Stomach Cancer Versus AP-PA Conventional Radiotherapy in NCI-Cairo

International Nuclear Information System (INIS)

El-Hossiny, H.A.; Diab, N.A.; El-Taher, M.M.

2009-01-01

This study was to compare this multiple field conformal technique to the AP-PA technique with respect to target volume coverage and dose to normal tissues. Materials and Methods: Seventeen patients with stages II-III denocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy presented to radiotherapy department in National Cancer Institute, Cairo in period between February 2009 to March 2010 using 3D conformal radiotherapy technique that consisted of a mono isocentric arrangement employing 4-6 radiation fields. For each patient, a second radiotherapy treatment plan was done using an antroposterior (AP-PA) fields, the two techniques were then compared using dose volume histogram (DVH) analysis. Results: Comparing different DVHs, it was found that the planning target volume (PTV) was adequately covered in both (3D and 2D) plans while the left kidney and spinal cord demonstrate lower radiation doses on using the conformal technique. The liver doses is higher in the 3D tecq, but still well below liver tolerance. Conclusions: Both 3D conformal radiotherapy and AP-PA conventional techniques doses are within range of normal tissues tolerance. Regarding the left kidney and spinal cord the 3D conformal radiotherapy is superior than the AP-PA conventional techniques but with higher doses to the liver in the 3D conformal radiotherapy compared to the AP-PA conventional techniques

Pacemaker and radiotherapy in breast cancer: is targeted intraoperative radiotherapy the answer in this setting?

International Nuclear Information System (INIS)

Keshtgar, Mohammed RS; Eaton, David J; Reynolds, Claire; Pigott, Katharine; Davidson, Tim; Gauter-Fleckenstein, Benjamin; Wenz, Frederik

2012-01-01

We present the case of an 83 year old woman with a cardiac pacemaker located close in distance to a subsequently diagnosed invasive ductal carcinoma of the left breast. Short range intraoperative radiotherapy was given following wide local excision and sentinel node biopsy. The challenges of using ionising radiation with pacemakers is also discussed

National Committee for the follow-up of measures for radiotherapy 2008-2011 - Final report

International Nuclear Information System (INIS)

Buzyn, A.; Grall, J.Y; Selleret, F.X.; Lacoste, A.C.; Maraninchi, D.; Harousseau, J-L.; Chauvet, B.; LE DU, D.; Saout, C.; Renody, N.; Depenweiller, C.; Goinere, R.

2012-06-01

As always more patients suffering from cancer are treated by radiotherapy, and as several over-irradiation events occurred in 2007, measures have been implemented to guarantee radiotherapy practice quality and safety. This document reports the work and actions performed by the national follow-up committee and its work groups to define, implement and follow-up these measures. They encompassed information actions towards patients, public, physicians and establishment managers, and new authorization measures. The committee also addressed radiotherapy professions involved in manipulation, dosimetry, as well as radio-physicists and radiotherapists. It introduced measures regarding vigilance in radiation, the improvement of quality and safety in radiation therapy centres, research and development, and the financing of these measures

Targeting the epidermal growth factor receptor in radiotherapy: radiobiological mechanisms, preclinical and clinical results

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Baumann, Michael; Krause, Mechthild

2004-01-01

Background and purpose: Inhibition of the epidermal growth factor receptor (EGFR) is a fastly developing field in preclinical and clinical cancer research. This review presents the current status of knowledge and discusses radiobiological mechanisms which may underly the efficacy of EGFR inhibitors combined with irradiation. Materials and methods: Preclinical and clinical results on combined targeting of the EGFR and irradiation from the literature and from this laboratory are reviewed. Focus is given to the radiobiological rationale of this approach and to endpoints of experimental radiotherapy. Results: Overexpression of the EGFR is associated with decreased local tumour control after radiotherapy, especially when the overall treatment time is long. Inhibition of the EGFR either alone or in combination with irradiation decreases the growth rate of tumours expressing this receptor. Preclinical data provide proof-of-principle that local tumour control may be improved by combining irradiation with C225 mAb. In a randomised phase III clinical trial, simultaneous irradiation and treatment with the EGFR antibody Cetuximab (Erbitux[reg]; C225) in head and neck cancer patients resulted in significantly improved locoregional tumour control and survival compared to curative irradiation alone. Acute skin reactions increased in the experimental arm. The underlying mechanisms of enhanced radiation effects of combined EGFR inhibition with irradiation and of the partly conflicting results in different studies are poorly understood. There is increasing evidence, that important intertumoral heterogeneity in the response to EGFR inhibition alone and combined with irradiation exists, which appears to be at least partly dependent on specific mutations of the receptor as well as of molecules that are involved in the intracellular signal transduction pathway. Conclusions and outlook: Further investigations at all levels of the translational research chain exploring the mechanisms of

Stage report of the national radiotherapy survey committee May 2009

International Nuclear Information System (INIS)

2009-01-01

This report proposes an assessment of the impact of the national radiotherapy measures present in the road map (November 2007 - March 2009) and describes the creation of a national support unit to manage the operating difficulties of 27 radiotherapy centres. It comments how a transition period between 2009 and 2011 must accompany radiotherapy before the implementation of opposable agreement criteria in 2011, notably through an improvement of recruitment, a support to cooperation between radiotherapy centres, the implementation of a radio-vigilance unit. Finally, it briefly discusses how to prepare the 2011-2013 period

Radiotherapy-induced emesis. An overview

International Nuclear Information System (INIS)

Feyer, P.; Buchali, A.; Hinkelbein, M.; Budach, V.; Zimmermann, J.S.; Titlbach, O.J.

1998-01-01

Background: A significant number of patients receiving radiotherapy experience the distressing side effects of emesis and nausea. These symptoms are some of the most distressing problems for the patients influencing their quality of life. Methods: International study results concerning radiotherapy-induced emesis are demonstrated. A German multicenter questionnaire examining the strategies to prevent or to treat radiotherapy-induced nausea and emesis is presented. An international analysis concerning incidence of emesis and nausea in fractionated radiotherapy patients is discussed. Finally the consensus of the consensus conference on antiemetic therapy from the Perugia International Cancer Conference V is introduced. Results: Untreated emesis can lead to complications like electrolyte disorders, dehydration, metabolic disturbances and nutrition problems with weight loss. Prophylactic antiemetics are often given to patients receiving single high-dose radiotherapy to the abdomen. A survey has revealed that antiemetic prophylaxis is not routinely offered to the patients receiving fractionated radiotherapy. However, there is a need for an effective treatment of emesis for use in this group of patients, too. In 20% of patients nausea and emesis can cause a treatment interruption because of an inadequate control of symptoms. Like in chemotherapy strategies there exist high, moderate, and low emetogenic treatment regimens in radiotherapy as well. The most emetogenic potential has the total body irradiation followed by radiotherapy to the abdomen. Radiotherapy induced emesis can be treated effectively with conventional antiemetics up to 50%. Conclusions: Studies with total body irradiation, fractionated treatment and high-dose single exposures have cleary demonstrated the value of 5-HT3-receptor antagonist antiemetics. There is a response between 60 and 97%. There is no difference in the efficacy of the different 5-HT3-antagonists. High-risk patients should be prophylactic

Clinical Experience With Image-Guided Radiotherapy in an Accelerated Partial Breast Intensity-Modulated Radiotherapy Protocol

International Nuclear Information System (INIS)

Leonard, Charles E.; Tallhamer, Michael M.S.; Johnson, Tim; Hunter, Kari C.M.D.; Howell, Kathryn; Kercher, Jane; Widener, Jodi; Kaske, Terese; Paul, Devchand; Sedlacek, Scot; Carter, Dennis L.

2010-01-01

Purpose: To explore the feasibility of fiducial markers for the use of image-guided radiotherapy (IGRT) in an accelerated partial breast intensity modulated radiotherapy protocol. Methods and Materials: Nineteen patients consented to an institutional review board approved protocol of accelerated partial breast intensity-modulated radiotherapy with fiducial marker placement and treatment with IGRT. Patients (1 patient with bilateral breast cancer; 20 total breasts) underwent ultrasound guided implantation of three 1.2- x 3-mm gold markers placed around the surgical cavity. For each patient, table shifts (inferior/superior, right/left lateral, and anterior/posterior) and minimum, maximum, mean error with standard deviation were recorded for each of the 10 BID treatments. The dose contribution of daily orthogonal films was also examined. Results: All IGRT patients underwent successful marker placement. In all, 200 IGRT treatment sessions were performed. The average vector displacement was 4 mm (range, 2-7 mm). The average superior/inferior shift was 2 mm (range, 0-5 mm), the average lateral shift was 2 mm (range, 1-4 mm), and the average anterior/posterior shift was 3 mm (range, 1 5 mm). Conclusions: This study shows that the use of IGRT can be successfully used in an accelerated partial breast intensity-modulated radiotherapy protocol. The authors believe that this technique has increased daily treatment accuracy and permitted reduction in the margin added to the clinical target volume to form the planning target volume.

Difference in target definition using three different methods to include respiratory motion in radiotherapy of lung cancer.

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Sloth Møller, Ditte; Knap, Marianne Marquard; Nyeng, Tine Bisballe; Khalil, Azza Ahmed; Holt, Marianne Ingerslev; Kandi, Maria; Hoffmann, Lone

2017-11-01

Minimizing the planning target volume (PTV) while ensuring sufficient target coverage during the entire respiratory cycle is essential for free-breathing radiotherapy of lung cancer. Different methods are used to incorporate the respiratory motion into the PTV. Fifteen patients were analyzed. Respiration can be included in the target delineation process creating a respiratory GTV, denoted iGTV. Alternatively, the respiratory amplitude (A) can be measured based on the 4D-CT and A can be incorporated in the margin expansion. The GTV expanded by A yielded GTV + resp, which was compared to iGTV in terms of overlap. Three methods for PTV generation were compared. PTV del (delineated iGTV expanded to CTV plus PTV margin), PTV σ (GTV expanded to CTV and A was included as a random uncertainty in the CTV to PTV margin) and PTV ∑ (GTV expanded to CTV, succeeded by CTV linear expansion by A to CTV + resp, which was finally expanded to PTV ∑ ). Deformation of tumor and lymph nodes during respiration resulted in volume changes between the respiratory phases. The overlap between iGTV and GTV + resp showed that on average 7% of iGTV was outside the GTV + resp implying that GTV + resp did not capture the tumor during the full deformable respiration cycle. A comparison of the PTV volumes showed that PTV σ was smallest and PTV Σ largest for all patients. PTV σ was in mean 14% (31 cm 3 ) smaller than PTV del , while PTV del was 7% (20 cm 3 ) smaller than PTV Σ . PTV σ yields the smallest volumes but does not ensure coverage of tumor during the full respiratory motion due to tumor deformation. Incorporating the respiratory motion in the delineation (PTV del ) takes into account the entire respiratory cycle including deformation, but at the cost, however, of larger treatment volumes. PTV Σ should not be used, since it incorporates the disadvantages of both PTV del and PTV σ .

Automatic block-matching registration to improve lung tumor localization during image-guided radiotherapy

Science.gov (United States)

Robertson, Scott Patrick

To improve relatively poor outcomes for locally-advanced lung cancer patients, many current efforts are dedicated to minimizing uncertainties in radiotherapy. This enables the isotoxic delivery of escalated tumor doses, leading to better local tumor control. The current dissertation specifically addresses inter-fractional uncertainties resulting from patient setup variability. An automatic block-matching registration (BMR) algorithm is implemented and evaluated for the purpose of directly localizing advanced-stage lung tumors during image-guided radiation therapy. In this algorithm, small image sub-volumes, termed "blocks", are automatically identified on the tumor surface in an initial planning computed tomography (CT) image. Each block is independently and automatically registered to daily images acquired immediately prior to each treatment fraction. To improve the accuracy and robustness of BMR, this algorithm incorporates multi-resolution pyramid registration, regularization with a median filter, and a new multiple-candidate-registrations technique. The result of block-matching is a sparse displacement vector field that models local tissue deformations near the tumor surface. The distribution of displacement vectors is aggregated to obtain the final tumor registration, corresponding to the treatment couch shift for patient setup correction. Compared to existing rigid and deformable registration algorithms, the final BMR algorithm significantly improves the overlap between target volumes from the planning CT and registered daily images. Furthermore, BMR results in the smallest treatment margins for the given study population. However, despite these improvements, large residual target localization errors were noted, indicating that purely rigid couch shifts cannot correct for all sources of inter-fractional variability. Further reductions in treatment uncertainties may require the combination of high-quality target localization and adaptive radiotherapy.

Configuration space analysis of common cost functions in radiotherapy beam-weight optimization algorithms

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Rowbottom, Carl Graham [Joint Department of Physics, Institute of Cancer Research and the Royal Marsden NHS Trust, Sutton, Surrey (United Kingdom); Webb, Steve [Joint Department of Physics, Institute of Cancer Research and the Royal Marsden NHS Trust, Sutton, Surrey (United Kingdom)

2002-01-07

The successful implementation of downhill search engines in radiotherapy optimization algorithms depends on the absence of local minima in the search space. Such techniques are much faster than stochastic optimization methods but may become trapped in local minima if they exist. A technique known as 'configuration space analysis' was applied to examine the search space of cost functions used in radiotherapy beam-weight optimization algorithms. A downhill-simplex beam-weight optimization algorithm was run repeatedly to produce a frequency distribution of final cost values. By plotting the frequency distribution as a function of final cost, the existence of local minima can be determined. Common cost functions such as the quadratic deviation of dose to the planning target volume (PTV), integral dose to organs-at-risk (OARs), dose-threshold and dose-volume constraints for OARs were studied. Combinations of the cost functions were also considered. The simple cost function terms such as the quadratic PTV dose and integral dose to OAR cost function terms are not susceptible to local minima. In contrast, dose-threshold and dose-volume OAR constraint cost function terms are able to produce local minima in the example case studied. (author)

Clinicopathologic Analysis of Microscopic Extension in Lung Adenocarcinoma: Defining Clinical Target Volume for Radiotherapy

International Nuclear Information System (INIS)

Grills, Inga S.; Fitch, Dwight L.; Goldstein, Neal S.; Yan Di; Chmielewski, Gary W.; Welsh, Robert J.; Kestin, Larry L.

2007-01-01

Purpose: To determine the gross tumor volume (GTV) to clinical target volume margin for non-small-cell lung cancer treatment planning. Methods: A total of 35 patients with Stage T1N0 adenocarcinoma underwent wedge resection plus immediate lobectomy. The gross tumor size and microscopic extension distance beyond the gross tumor were measured. The nuclear grade and percentage of bronchoalveolar features were analyzed for association with microscopic extension. The gross tumor dimensions were measured on a computed tomography (CT) scan (lung and mediastinal windows) and compared with the pathologic dimensions. The potential coverage of microscopic extension for two different lung stereotactic radiotherapy regimens was evaluated. Results: The mean microscopic extension distance beyond the gross tumor was 7.2 mm and varied according to grade (10.1, 7.0, and 3.5 mm for Grade 1 to 3, respectively, p < 0.01). The 90th percentile for microscopic extension was 12.0 mm (13.0, 9.7, and 4.4 mm for Grade 1 to 3, respectively). The CT lung windows correlated better with the pathologic size than did the mediastinal windows (gross pathologic size overestimated by a mean of 5.8 mm; composite size [gross plus microscopic extension] underestimated by a mean of 1.2 mm). For a GTV contoured on the CT lung windows, the margin required to cover microscopic extension for 90% of the cases would be 9 mm (9, 7, and 4 mm for Grade 1 to 3, respectively). The potential microscopic extension dosimetric coverage (55 Gy) varied substantially between the stereotactic radiotherapy schedules. Conclusion: For lung adenocarcinomas, the GTV should be contoured using CT lung windows. Although a GTV based on the CT lung windows would underestimate the gross tumor size plus microscopic extension by only 1.2 mm for the average case, the clinical target volume expansion required to cover the microscopic extension in 90% of cases could be as large as 9 mm, although considerably smaller for high-grade tumors

Use of Maximum Intensity Projections (MIPs) for target outlining in 4DCT radiotherapy planning.

Science.gov (United States)

Muirhead, Rebecca; McNee, Stuart G; Featherstone, Carrie; Moore, Karen; Muscat, Sarah

2008-12-01

Four-dimensional computed tomography (4DCT) is currently being introduced to radiotherapy centers worldwide, for use in radical radiotherapy planning for non-small cell lung cancer (NSCLC). A significant drawback is the time required to delineate 10 individual CT scans for each patient. Every department will hence ask the question if the single Maximum Intensity Projection (MIP) scan can be used as an alternative. Although the problems regarding the use of the MIP in node-positive disease have been discussed in the literature, a comprehensive study assessing its use has not been published. We compared an internal target volume (ITV) created using the MIP to an ITV created from the composite volume of 10 clinical target volumes (CTVs) delineated on the 10 phases of the 4DCT. 4DCT data was collected from 14 patients with NSCLC. In each patient, the ITV was delineated on the MIP image (ITV_MIP) and a composite ITV created from the 10 CTVs delineated on each of the 10 scans in the dataset. The structures were compared by assessment of volumes of overlap and exclusion. There was a median of 19.0% (range, 5.5-35.4%) of the volume of ITV_10phase not enclosed by the ITV_MIP, demonstrating that the use of the MIP could result in under-treatment of disease. In contrast only a very small amount of the ITV_MIP was not enclosed by the ITV_10phase (median of 2.3%, range, 0.4-9.8%), indicating the ITV_10phase covers almost all of the tumor tissue as identified by MIP. Although there were only two Stage I patients, both demonstrated very similar ITV_10phase and ITV_MIP volumes. These findings suggest that Stage I NSCLC tumors could be outlined on the MIP alone. In Stage II and III tumors the ITV_10phase would be more reliable. To prevent under-treatment of disease, the MIP image can only be used for delineation in Stage I tumors.

True Local Recurrence Rate in the Conserved Breast After Magnetic Resonance Imaging-Targeted Radiotherapy

International Nuclear Information System (INIS)

Whipp, Elisabeth; Beresford, Mark; Sawyer, Elinor; Halliwell, Michael

2010-01-01

Purpose: Better accuracy of local radiotherapy may substantially improve local control and thus long-term breast cancer survival. Magnetic resonance imaging (MRI) has high resolution and sensitivity in breast tissue and may depict the tumor bed more accurately than conventional planning techniques. A postoperative complex (POCx) comprises all visible changes thought to be related to surgery within the breast and acts as a surrogate for the tumor bed. This study reports on local recurrence rates after MRI-assisted radiotherapy planning to ensure adequate coverage of the POCx. Methods and Materials: Simple opposed tangential fields were defined by surface anatomy in the conventional manner in 221 consecutive patients. After MRI, fields were modified by a single radiation oncologist to ensure encompassment of the POCx with a 10-mm margin. Genetic analysis was performed on all local relapses (LRs) to distinguish true recurrences (TRs) from new primaries (NPs). Results: This was a high risk cohort at 5 years: only 9.5% were classified as low risk (St Gallen): 43.4% were Grade 3 and 19.9% had surgical margins <1 mm; 62.4% of patients received boosts. Adjustments of standard field margins were required in 69%. After a median follow-up of 5 years, there were 3 LRs (1.3%) as the site of first relapse in 221 patients, comprising two TRs (0.9%) and one NP (0.4%). Conclusions: Accurate targeting of the true tumor bed is critical. MRI may better define the tumor bed.

Biological modelling of fuzzy target volumes in 3D radiotherapy

International Nuclear Information System (INIS)

Levegruen, S.; Kampen, M. van; Waschek, T.; Engenhart, R.; Schlegel, W.

1995-01-01

Purpose/Objective: The outcome of each radiotherapy depends critically on the optimal choice of the target volume. The goal of the radiotherapist is to include all tumor spread at the same time as saving as much healthy tissue as possible. Even when the information of all imaging modalities is combined, the diagnostic techniques are not sensitive and specific enough to visualize all microscopic tumor cell spread. Due to this lack of information there is room for different interpretations concerning the extend of the target volume, leading to a fuzzy target volume. The aim of this work is to develop a model to score different target volume boundaries within the region of diagnostic uncertainty in terms of tumor control probability (TCP) and normal tissue complication probabilities (NTCP). Materials and Methods: In order to assess the region of diagnostic uncertainty, the radiotherapist defines interactively a minimal planning target volume that absolutely must be irradiated according to the diagnostic information available and a maximal planning target volume outside which no tumor cell spread is expected. For the NTCP calculation we use the Lyman 4 parameter model to estimate the response of an organ at risk to a uniform partial volume irradiation. The TCP calculation is based on the Poisson model of cell killing. The TCP estimation depends not only on volume, dose, clonogenic cell density and the α parameter of the linear quadratic model but also on the probability to find clonogenic cells in the considered volume. Inside the minimal PTV this probability is 1, outside the maximal PTV it is 0. Therefore all voxels inside the minimal PTV are assigned the value of 1 with respect to the target volume, all voxels outside the maximal PTV the value of 0. For voxels in the region of uncertainty in between, a 3D linear interpolation is performed. Here we assume the probability to follow the interpolated values. Starting with the minimal PTV, the expected gain in TCP and

Prostatic cancer: intolerance and morbidity of external radiotherapy

International Nuclear Information System (INIS)

Douchez, J.; Fregevu, Y.; Allain, Y.M.; Cellier, P.; Fenton, J.; Hay, M.; Le Bourgeois, J.P.; Vincent, F.

1985-01-01

The pertherapeutic intolerance and morbidity are analyzed in a groupe of 597 patients with localized prostatic carcinoma treated by definitive radiotherapy between 1975 and 1982. Minimum follow-up is 2 years, median is 46 months. The results are compared to following parameters: associated diseases, associated surgical treatments, doses and irradiated target volumes. Pertherapeutic intolerance manifestations were found in 73% of patients and lead to complications. Urinary incontinence and chronic cystitis were more frequent after transurethral resection or prostatic target volume and by split course irradiation. Chronic diarrhea was more frequent when using large target volume. Leg edema was closely associated with pelvic lymphadenectomy. The control of pertherapeutic manifestations and the prevention of complications should improve survival in patients treated by external radiotherapy [fr

Probe into rational target volume of nasopharyngeal carcinoma having been treated with conventional radiotherapy

International Nuclear Information System (INIS)

Zheng Yingjie; Zhao Chong; Lu Lixia; Wu Shaoxiong; Cui Nianji; Chen Fujin

2006-01-01

Objective: To analyze the local control rate and the dosimetric patterns of local recurrence in nasopharyngeal carcinoma (NPC) patients having been treated with standardized conventional radiotherapy and to evaluate the delineation of rational target volume. Methods: From Jan. 2000 to Dec. 2000, 476 patients with untreated NPC were treated by standardized conventional radiotherapy alone at the Sun Yat-sen University Cancer Center. The radiation ports were designed on a X-ray simulator. The nasopharyngeal lesion demonstrated by CT scan and the subclinical spread regions adjacent to the nasopharynx were defined as the target volume. Kaplan- Meier method was used to calculate the cumulative local recurrence rate. For patients with local recurrence, the primary and recurrent local tumor volumes(V nx , V recur ) were delineated with three-dimensional treatment planning system(3DTPS), and the dataset of radiation ports and delivered prescription dose to the 3DTPS were transferred according to the first treatment. The dose of radiation received by V recur was calculated and analyzed with dose- volume histogram(DVH). Local recurrence was classified as: 1. 'in-port' with 95% or more of the recurrence volume ( recur V 95 ) was within the 95% isodose; 2. 'marginal' with 20% to 95% of recur V 95 within the 95% isodose; 3. o utside w ith only less than 20% of recur V 95 within the 95% isodose curve. Results: With the median follow- up of 42.5 months (range 8-54 months), 52 patients developed local recurrence. The 1-, 2-, 3 and 4-year cumulative local failure rate was 0.6%, 3.9%, 8.7% and 11.5%, respectively. Among the 42 local recurrent patients who could be analyzed by 3DTPS, 52% were in-port, 40% were marginal and 7% were outside. For most of the marginal recurrence and all the outside recurrence patients, the main reason of recurrence were related to the unreasonable design of the radiation port and inaccuracy in the interpretation image findings. Conclusions: The outcome of

Target volume definition in conformal radiotherapy for prostate cancer: quality assurance in the MRC RT-01 trial

International Nuclear Information System (INIS)

Seddon, B.S.; Wilson, J.; Khoo, V.; Dearnaley, D.; Bidmead, M.

2000-01-01

Prior to randomization of patients into the UK Medical Research Council multicentre randomized trial (RT-01) of conformal radiotherapy (CFRT) in prostate cancer, clinicians at participating centres were required to complete a quality assurance (QA) clinical planning exercise to enable an investigation of inter-observer variability in gross target volume (GTV) and normal structure outlining. Thirteen participating centres and two investigators completed the clinical planning exercise of three practice planning cases. Clinicians were asked to draw outlines of the GTV, rectum and bladder on hard-copy computerized tomography (CT) films of the pelvis, which were transferred onto the Cadplan computer planning system by a single investigator. Centre, inferior and superior CT levels of GTV, rectum and bladder were noted, and volume calculations performed. Planning target volumes (PTV) were generated using automatic volume expansion of GTVs by a 1 cm margin. Anterior, right and left lateral beam eye views (BEV) of the PTVs were generated. Using a common central point, the BEV PTVs were superimposed for each beam direction of each case. Radial PTV variation was investigated by measurement of a novel parameter, termed the radial line measurement variation (RLMV). GTV central slice and length were defined with reasonable consistency. The RLMV analysis showed that the main part of the prostate gland, bladder and inferior rectum were outlined with good consistency among clinicians. However, the outlining of the prostatic apex, superior aspect of the prostate projecting into the bladder, seminal vesicles, the base of seminal vesicles and superior rectum were more variable. This exercise has demonstrated adequate consistency of GTV definition. The RLMV method of analysis indicates particular regions of clinician uncertainty. Appropriate feedback has been given to all participating clinicians, and the final RT-01 trial protocol has been modified to accommodate these findings

Daily targeting of intrahepatic tumors for radiotherapy

International Nuclear Information System (INIS)

Balter, James M.; Brock, Kristy K.; Litzenberg, Dale W.; McShan, Daniel L.; Lawrence, Theodore S.; Haken, Randall Ten; McGinn, Cornelius J.; Lam, Kwok L.; Dawson, Laura A.

2002-01-01

Introduction: A system has been developed for daily targeting of intrahepatic tumors using a combination of ventilatory immobilization, in-room diagnostic imaging, and on-line setup adjustment. By reducing geometric position uncertainty, as well as organ movement, this system permits reduction of margins and thus potentially higher treatment doses. This paper reports our initial experience treating 8 patients with focal liver tumors using this system. Methods and Materials: The system includes diagnostic X-ray tubes mounted on the wall and ceiling of a treatment room, an active matrix flat panel imager, in-room control for image acquisition and setup adjustment, and a ventilatory immobilization system via active breathing control (ABC). Eight patients participated in the study, two using an early prototype ABC unit, and the remaining six with a commercial ABC system and improved setup measurement tools. Treatment margins were reduced, and dose consequently increased because of increased confidence in target position under this protocol. After daily setup via skin marks, orthogonal radiographs were acquired at suspended ventilation. The images were aligned to the CT model using the diaphragm for inferior-superior (IS) alignment, and the skeleton for left-right (LR) and anterior-posterior (AP) alignment. Adjustments were made for positioning errors greater than a threshold (3 or 5 mm). After treatment, retrospective analysis determined the final setup accuracy, as well as the error in initial setup measurement performed before setup adjustment. Results: Two hundred sixty-two treatment fractions were delivered on eight patients, with 171 treatments requiring repositioning. Typical treatment times were 25-30 min. Patients were able to tolerate ABC throughout the course of treatment. Breath holds up to 35 s long were used for treatment. The use of on-line imaging and setup adjustment reduced setup errors (σ) from 4.0 mm (LR), 6.7 mm (IS), and 3.8 mm (AP) to 2.1 mm (LR

211At-labelling of polymer particles for radiotherapy: synthesis, purification and stability

International Nuclear Information System (INIS)

Larsen, R.H.; Hassfjell, S.P.; Hoff, P.; Alstad, J.; Bjoergum, J.

1993-01-01

Cyclotron-produced 211 At was distilled from a Bi metal target and coupled to N-succinimidyl-3-(trimethylstannyl)benzoate. The resulting N-succinimidyl-3-( 211 At)astatobenzoate was thereafter coupled to aminated monosized polymer particles with a diameter of 1.8 μm. The total time elapsed from the end of the cyclotron irradiation until the final product was prepared was about 2.5 hours. From 23 to 51% of the target activity at the end of bombardment was measured in the final conjugate. Solid-liquid extraction purification of the astatinated intermediate, using Sep-pak columns (Waters), gave more reproducible yields in the final conjugation step. The 211 At-labelled particles were incubated with fetal calf serum, human serum and human full blood at room temperature. The 211 At activity on the particles was measured before and after three times washing at 4, 24 and 48 hours. The stability was not significantly different from 100% for all media and for all time points. This indicates that 211 At-labelled particles can be stable under in vivo conditions, and may thereby be a promising agent for intracavitary radiotherapy on free-floating cancer cells or surface fixed cells. (Author)

Evaluation of dose coverage to target volume and normal tissue sparing in the adjuvant radiotherapy of gastric cancers: 3D-CRT compared with dynamic IMRT.

Science.gov (United States)

Murthy, Kk; Shukeili, Ka; Kumar, Ss; Davis, Ca; Chandran, Rr; Namrata, S

2010-01-01

To assess the potential advantage of intensity-modulated radiotherapy (IMRT) over 3D-conformal radiotherapy (3D-CRT) planning in postoperative adjuvant radiotherapy for patients with gastric carcinoma. In a retrospective study, for plan comparison, dose distribution was recalculated in 15 patients treated with 3D-CRT on the contoured structures of same CT images using an IMRT technique. 3D-conformal plans with three fields and four-fields were compared with seven-field dynamic IMRT plans. The different plans were compared by analyzing the dose coverage of planning target volume using TV(95), D(mean), uniformity index, conformity index and homogeneity index parameters. To assess critical organ sparing, D(mean), D(max), dose to one-third and two-third volumes of the OARs and percentage of volumes receiving more than their tolerance doses were compared. The average dose coverage values of PTV with 3F-CRT and 4F-CRT plans were comparable, where as IMRT plans achieved better target coverage(p3D-CRT plans. The doses to the liver and bowel reduced significantly (p3D-CRT plans. For all OARs the percentage of volumes receiving more than their tolerance doses were reduced with the IMRT plans. This study showed that a better target coverage and significant dose reduction to OARs could be achieved with the IMRT plans. The IMRT can be preferred with caution for organ motion. The authors are currently studying organ motion in the upper abdomen to use IMRT for patient treatment.

Targeted radiotherapy with {sup 177} Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

Energy Technology Data Exchange (ETDEWEB)

Murphy, M. A de; Pedraza L, M. [Department of Nuclear Medicine, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico D.F. (Mexico); Rodriguez C, J. [Faculty of Medicine, UAEM, Toluca, Estado de Mexico (Mexico); Ferro F, G. [ININ, 52045 Estado de Mexico (Mexico); Murphy S, E. [Hospital Santelena, Mexico D.F. (Mexico)

2006-07-01

Malignant pancreas tumours induced in athymic mice are a good model for targeted radiotherapy. The objective of this research was to estimate pancreatic tumour absorbed radiation doses and to evaluate {sup 177}Lu-DOTA-TATE as a therapeutic radiopharmaceutical that could be used in humans. AR42J murine pancreas cancer cells, which over-express somatostatin receptors, were injected in athymic mice and 20 days later the mean tumour size was 3.08 square cm (n=3). A mean of 86.3 MBq {sup 177}Lu-DOTA-TATE, was injected in a tail vein and 19 days after therapy the size of the tumours was 0.81 square cm. There was a partial relapse and after 16 days, when sacrificed, the mean tumour size was 8.28 cubic cm. An epithelial and sarcoma mixed tumour in the kidney of one treated mouse was found. The tumour of the control mouse was 8.61 cubic cm when sacrificed 14 days after tumour induction. Radiotherapy estimates to the tumours was 35.9-39.7 Gy and the tumours might have been completely reduced with a second therapy dose. These preliminary studies justify further therapeutic and dosimetry estimations to ensure that Lu-{sup 177}-DOTA-TATE will act as expected in man, considering kidney radiation. (Author)

[Radiotherapy of oropharynx carcinoma].

Science.gov (United States)

Servagi Vernat, S; Tochet, F; Vieillevigne, L; Pointreau, Y; Maingon, P; Giraud, P

2016-09-01

Indication, doses, technique of radiotherapy and concomitant chemotherapy for oropharynx carcinoma are presented. The recommendations for delineation of the target volumes and organs at risk are detailed. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Cervix cancer: clinical aspects of tumoral control and radiotherapy treatment time

International Nuclear Information System (INIS)

Petitto, J.V.

1994-01-01

The author analyzed 35 patients with recurrence or residual tumor at the end of the radiotherapy program. These patients were selected out of a group of 338 patients cervix cancer who had also undergone on the same radiotherapy program. Those patients were compared with control group of 30 patients without clinical evidence of the disease, from the same group of 338 patients. It has studied the clinical results considering the total radiotherapy time to developed the radiation program and factors that could modify the time for a longer program, and also modify the final survival results. No significant difference was shown in this study, but it should be taken in consideration the total radiotherapy time, because this is a factor that could change the final results if the time would be longer than what was shown in this work. (author). 26 refs, 10 tabs

11C-CHO PET in optimization of target volume delineation and treatment regimens in postoperative radiotherapy for brain gliomas

International Nuclear Information System (INIS)

Li Fangming; Nie Qing; Wang Ruimin; Chang, Susan M.; Zhao Wenrui; Zhu Qi; Liang Yingkui; Yang Ping; Zhang Jun; Jia Haiwei; Fang Henghu

2012-01-01

Objective: We explored the clinical values of 11 C-choline ( 11 C-CHO) PET in optimization of target volume delineation and treatment regimens in postoperative radiotherapy for brain gliomas. Methods: Sixteen patients with the pathological confirmation of the diagnosis of gliomas prior to receiving radiotherapy (postoperative) were included, and on whom both MRI and CHO PET scans were performed at the same position for comparison of residual tumors with the two techniques. 11 C-CHO was used as the tracer in the PET scan. A plain T1-weighted, T2-weighted and contrast-enhanced T1-weighted imaging scans were performed in the MRI scan sequence. The gliomas' residual tumor volume was defined as the area with CHO-PET high-affinity uptake and metabolism (V CHO ) and one with MRI T1-weighted imaging high signal intensity (V Gd ), and was determined by a group of experienced professionals and clinicians. Results: (1) In CHO-PET images, the tumor target volume, i.e., the highly metabolic area with a high concentration of isotopes (SUV 1.016–4.21) and the corresponding contralateral normal brain tissues (SUV0.1–0.62), was well contrasted, and the boundary between lesions and surrounding normal brain tissues was better defined compared with MRI and 18 F-FDG PET images. (2) For patients with brain gliomas of WHO Grade II, the SUV was 1.016–2.5; for those with WHO Grades III and IV, SUVs were >26–4.2. (3) Both CHO PET and MRI were positive for 10 patients and negative for 2 patients. The residual tumor consistency between these two studies was 75%. Four of the 10 CHO-PET-positive patients were negative on MRI scans. The maximum distance between V Gd and V CHO margins was 1.8 cm. (4) The gross tumor volumes (GTVs) and the ensuing treatment regimens were changed for 31.3% (5/16) of patients based on the CHO-PET high-affinity uptake and metabolism, in which the change rate was 80% (4/5), 14.3 % (1/7) and 0% (0/4) for patients with WHO Grade II III, and IV gliomas

135La as an Auger-electron emitter for targeted internal radiotherapy

Science.gov (United States)

Fonslet, J.; Lee, B. Q.; Tran, T. A.; Siragusa, M.; Jensen, M.; Kibédi, T.; E Stuchbery, A.; Severin, G. W.

2018-01-01

135La has favorable nuclear and chemical properties for Auger-based targeted internal radiotherapy. Here we present detailed investigations of the production, emissions, and dosimetry related to 135La therapy. 135La was produced by 16.5 MeV proton irradiation of metallic natBa on a medical cyclotron, and was isolated and purified by trap-and-release on weak cation-exchange resin. The average production rate was 407  ±  19 MBq µA-1 (saturation activity), and the radionuclidic purity was 98% at 20 h post irradiation. Chemical separation recovered  >  98 % of the 135La with an effective molar activity of 70  ±  20 GBq µmol-1. To better assess cellular and organ dosimetry of this nuclide, we have calculated the x-ray and Auger emission spectra using a Monte Carlo model accounting for effects of multiple vacancies during the Auger cascade. The generated Auger spectrum was used to calculate cellular S-factors. 135La was produced with high specific activity, reactivity, radionuclidic purity, and yield. The emission spectrum and the dosimetry are favorable for internal radionuclide therapy.

Poster - 36: Effect of Planning Target Volume Coverage on the Dose Delivered in Lung Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Dekker, Chris; Wierzbicki, Marcin [McMaster University, Juravinski Cancer Centre (Canada)

2016-08-15

Purpose: In lung radiotherapy, breathing motion may be encompassed by contouring the internal target volume (ITV). Remaining uncertainties are included in a geometrical expansion to the planning target volume (PTV). In IMRT, the treatment is then optimized until a desired PTV fraction is covered by the appropriate dose. The resulting beams often carry high fluence in the PTV margin to overcome low lung density and to generate steep dose gradients. During treatment, the high density tumour can enter the PTV margin, potentially increasing target dose. Thus, planning lung IMRT with a reduced PTV dose may still achieve the desired ITV dose during treatment. Methods: A retrospective analysis was carried out with 25 IMRT plans prescribed to 63 Gy in 30 fractions. The plans were re-normalized to cover various fractions of the PTV by different isodose lines. For each case, the isocentre was moved using 125 shifts derived from all 3D combinations of 0 mm, (PTV margin - 1 mm), and PTV margin. After each shift, the dose was recomputed to approximate the delivered dose. Results and Conclusion: Our plans typically cover 95% of the PTV by 95% of the dose. Reducing the PTV covered to 94% did not significantly reduce the delivered ITV doses for (PTV margin - 1 mm) shifts. Target doses were reduced significantly for all other shifts and planning goals studied. Thus, a reduced planning goal will likely deliver the desired target dose as long as the ITV rarely enters the last mm of the PTV margin.

Voluntary Deep Inspiration Breath-hold Reduces the Heart Dose Without Compromising the Target Volume Coverage During Radiotherapy for Left-sided Breast Cancer.

Science.gov (United States)

Al-Hammadi, Noora; Caparrotti, Palmira; Naim, Carole; Hayes, Jillian; Rebecca Benson, Katherine; Vasic, Ana; Al-Abdulla, Hissa; Hammoud, Rabih; Divakar, Saju; Petric, Primoz

2018-03-01

During radiotherapy of left-sided breast cancer, parts of the heart are irradiated, which may lead to late toxicity. We report on the experience of single institution with cardiac-sparing radiotherapy using voluntary deep inspiration breath hold (V-DIBH) and compare its dosimetric outcome with free breathing (FB) technique. Left-sided breast cancer patients, treated at our department with postoperative radiotherapy of breast/chest wall +/- regional lymph nodes between May 2015 and January 2017, were considered for inclusion. FB-computed tomography (CT) was obtained and dose-planning performed. Cases with cardiac V25Gy ≥ 5% or risk factors for heart disease were coached for V-DIBH. Compliant patients were included. They underwent additional CT in V-DIBH for planning, followed by V-DIBH radiotherapy. Dose volume histogram parameters for heart, lung and optimized planning target volume (OPTV) were compared between FB and BH. Treatment setup shifts and systematic and random errors for V-DIBH technique were compared with FB historic control. Sixty-three patients were considered for V-DIBH. Nine (14.3%) were non-compliant at coaching, leaving 54 cases for analysis. When compared with FB, V-DIBH resulted in a significant reduction of mean cardiac dose from 6.1 +/- 2.5 to 3.2 +/- 1.4 Gy (p FB and V-DIBH, respectively (p FB- and V-DIBH-derived mean lung dose (11.3 +/- 3.2 vs. 10.6 +/- 2.6 Gy), lung V20Gy (20.5 +/- 7 vs. 19.5 +/- 5.1 Gy) and V95% for the OPTV (95.6 +/- 4.1 vs. 95.2 +/- 6.3%) were non-significant. V-DIBH-derived mean shifts for initial patient setup were ≤ 2.7 mm. Random and systematic errors were ≤ 2.1 mm. These results did not differ significantly from historic FB controls. When compared with FB, V-DIBH demonstrated high setup accuracy and enabled significant reduction of cardiac doses without compromising the target volume coverage. Differences in lung doses were non-significant.

Radiotherapy equipment and departments in the European countries: final results from the ESTRO-HERO survey.

Science.gov (United States)

Grau, Cai; Defourny, Noémie; Malicki, Julian; Dunscombe, Peter; Borras, Josep M; Coffey, Mary; Slotman, Ben; Bogusz, Marta; Gasparotto, Chiara; Lievens, Yolande; Kokobobo, Arianit; Sedlmayer, Felix; Slobina, Elena; Feyen, Karen; Hadjieva, Tatiana; Odrazka, Karel; Grau Eriksen, Jesper; Jaal, Jana; Bly, Ritva; Chauvet, Bruno; Willich, Normann; Polgar, Csaba; Johannsson, Jakob; Cunningham, Moya; Magrini, Stefano; Atkocius, Vydmantas; Untereiner, Michel; Pirotta, Martin; Karadjinovic, Vanja; Levernes, Sverre; Sladowski, Krystol; Lurdes Trigo, Maria; Šegedin, Barbara; Rodriguez, Aurora; Lagerlund, Magnus; Pastoors, Bert; Hoskin, Peter; Vaarkamp, Jaap; Cleries Soler, Ramon

2014-08-01

Documenting the distribution of radiotherapy departments and the availability of radiotherapy equipment in the European countries is an important part of HERO - the ESTRO Health Economics in Radiation Oncology project. HERO has the overall aim to develop a knowledge base of the provision of radiotherapy in Europe and build a model for health economic evaluation of radiation treatments at the European level. The aim of the current report is to describe the distribution of radiotherapy equipment in European countries. An 84-item questionnaire was sent out to European countries, principally through their national societies. The current report includes a detailed analysis of radiotherapy departments and equipment (questionnaire items 26-29), analyzed in relation to the annual number of treatment courses and the socio-economic status of the countries. The analysis is based on validated responses from 28 of the 40 European countries defined by the European Cancer Observatory (ECO). A large variation between countries was found for most parameters studied. There were 2192 linear accelerators, 96 dedicated stereotactic machines, and 77 cobalt machines reported in the 27 countries where this information was available. A total of 12 countries had at least one cobalt machine in use. There was a median of 0.5 simulator per MV unit (range 0.3-1.5) and 1.4 (range 0.4-4.4) simulators per department. Of the 874 simulators, a total of 654 (75%) were capable of 3D imaging (CT-scanner or CBCT-option). The number of MV machines (cobalt, linear accelerators, and dedicated stereotactic machines) per million inhabitants ranged from 1.4 to 9.5 (median 5.3) and the average number of MV machines per department from 0.9 to 8.2 (median 2.6). The average number of treatment courses per year per MV machine varied from 262 to 1061 (median 419). While 69% of MV units were capable of IMRT only 49% were equipped for image guidance (IGRT). There was a clear relation between socio-economic status, as

Radiotherapy equipment and departments in the European countries: Final results from the ESTRO-HERO survey

International Nuclear Information System (INIS)

Grau, Cai; Defourny, Noémie; Malicki, Julian; Dunscombe, Peter; Borras, Josep M.; Coffey, Mary; Slotman, Ben; Bogusz, Marta; Gasparotto, Chiara; Lievens, Yolande; Kokobobo, Arianit; Sedlmayer, Felix; Slobina, Elena; Feyen, Karen; Hadjieva, Tatiana; Odrazka, Karel; Eriksen, Jesper Grau; Jaal, Jana; Bly, Ritva; Chauvet, Bruno

2014-01-01

Background: Documenting the distribution of radiotherapy departments and the availability of radiotherapy equipment in the European countries is an important part of HERO – the ESTRO Health Economics in Radiation Oncology project. HERO has the overall aim to develop a knowledge base of the provision of radiotherapy in Europe and build a model for health economic evaluation of radiation treatments at the European level. The aim of the current report is to describe the distribution of radiotherapy equipment in European countries. Methods: An 84-item questionnaire was sent out to European countries, principally through their national societies. The current report includes a detailed analysis of radiotherapy departments and equipment (questionnaire items 26–29), analyzed in relation to the annual number of treatment courses and the socio-economic status of the countries. The analysis is based on validated responses from 28 of the 40 European countries defined by the European Cancer Observatory (ECO). Results: A large variation between countries was found for most parameters studied. There were 2192 linear accelerators, 96 dedicated stereotactic machines, and 77 cobalt machines reported in the 27 countries where this information was available. A total of 12 countries had at least one cobalt machine in use. There was a median of 0.5 simulator per MV unit (range 0.3–1.5) and 1.4 (range 0.4–4.4) simulators per department. Of the 874 simulators, a total of 654 (75%) were capable of 3D imaging (CT-scanner or CBCT-option). The number of MV machines (cobalt, linear accelerators, and dedicated stereotactic machines) per million inhabitants ranged from 1.4 to 9.5 (median 5.3) and the average number of MV machines per department from 0.9 to 8.2 (median 2.6). The average number of treatment courses per year per MV machine varied from 262 to 1061 (median 419). While 69% of MV units were capable of IMRT only 49% were equipped for image guidance (IGRT). There was a clear

Design of planning target volume margin using an active breathing control and Varian image-guided radiotherapy (IGRT) system in unresectable liver tumor

International Nuclear Information System (INIS)

Yue Jinbo; Yu Jinming; Liu Jing; Liu Tonghai; Yin Yong; Shi Xuetao; Song Jinlong

2007-01-01

Objective: To define the planning target volume(PTV) margin with an active breathing control (ABC) and the Varian image-guided radiotherapy (IGRT) system. Methods: Thirteen patients with liver cancer were treated with radiotherapy from May 2006 to September 2006. Prior to radiotherapy, all patients had undergone transarterial chemoembolization (TACE) by infusing a mixture of iodized oil contrast medium and chemotherapeutic agents, kV fluoroscopy was used to measure the potential motion of lipiodol spot positions during ABC breath-holds. ABC was used for planning CT scan and radiation delivery, with the breath held at the same phase of the respiratory cycle (near end-exhalation). Cone beam CT (CBCT) was taken using Varian IGRT system, which was then compared online with planning CT using a 3 D-3 D matching tool. Analysis relied on lipiodol spots on planning CT and CBCT manually. The treatment table was moved to produce acceptable setup before treatment delivery. Repeated CBCT image and another analysis were obtained after irradiation. Results: No motion of the intrahepatic tumor was observed on fluoroscopy during ABC breath-holds. The estimated required PTV margins, calculated according to the Stroom formula, were 4.4 mm, 5.3 mm and 7.8 mm in the x, y and z axis directions before radiotherapy. The corresponding parameters were 2.5m, 2.6 mm and 3.9 mm after radiotherapy. Conclusions: We have adopted a PTV margin of 5 mm, 6 mm and 8 mm in the x, y and z axis directions with ABC, and 3,3 and 4 mm with ABC and on-line kilovoltage CBCT. (authors)

Epithelioid hemangioendothelioma of the spine treated with RapidArc volumetric-modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Guy, Jean-Baptiste; Trone, Jane-Chloé [Department of Radiotherapy, Institut de Cancérologie de la Loire, St Priest en Jarez (France); Chargari, Cyrus [Department of Radiation Oncology, HIA du Val de Grâce, Paris (France); Falk, Alexander Tuan [Department of Radiation Oncology, Centre Antoine Lacassagne, Nice (France); Khodri, Mustapha [Department of Physics, Institut de Cancérologie de la Loire, St Priest en Jarez (France); Magné, Nicolas, E-mail: nicolas.magne@icloire.fr [Department of Radiotherapy, Institut de Cancérologie de la Loire, St Priest en Jarez (France)

2014-10-01

Radiotherapy for epithelioid hemangioendothelioma (EHE) using volumetric intensity-modulated arc radiotherapy (VMAT). A 48-year-old woman was referred for curative irradiation of a vertebral EHE after failure of surgery. A comparison between VMAT and conventional conformal tridimensional (3D) dosimetry was performed and potential advantage of VMAT for sparing critical organs from irradiation's side effects was discussed. The total delivered dose on the planning target volume was 54 Gy in 27 fractions. The patient was finally treated with VMAT. The tolerance was excellent. There was no acute toxicity, including no increase in pain. With a follow-up of 18 months, no delayed toxicity was reported. The clinical response consisted of a decrease in the dorsal pain. The D{sub max} for the spinal cord was reduced from 55 Gy (3D-radiotherapy [RT]) (which would be an unacceptable dose to the spine because of the risk of myelopathy) to 42.8 Gy (VMAT), which remains below the recommended dose threshold (45 Gy). The dose delivered to 20% of organ volume (D{sub 20}) was reduced from 47 Gy (3D-RT) to 3 Gy (VMAT) for the spinal cord. The study shows that VMAT allows the delivery of curative treatment for vertebral EHEs because of critical organ sparing.

Dosimetric Study of Current Treatment Options for Radiotherapy in Retinoblastoma

Energy Technology Data Exchange (ETDEWEB)

Eldebawy, Eman [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Department of Radiation Oncology, Children' s Cancer Hospital, Cairo (Egypt); Parker, William, E-mail: william.parker@mcgill.ca [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Abdel Rahman, Wamied [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Freeman, Carolyn R. [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada)

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.

Evaluation of Peritumoral Edema in the Delineation of Radiotherapy Clinical Target Volumes for Glioblastoma

International Nuclear Information System (INIS)

Chang, Eric L.; Akyurek, Serap; Avalos, Tedde C; Rebueno, Neal C; Spicer, Chris C; Garcia, John C; Famiglietti, Robin; Allen, Pamela K.; Chao, K.S. Clifford; Mahajan, Anita; Woo, Shiao Y.; Maor, Moshe H.

2007-01-01

Purpose: To evaluate the spatial relationship between peritumoral edema and recurrence pattern in patients with glioblastoma (GBM). Methods and Materials: Forty-eight primary GBM patients received three-dimensional conformal radiotherapy that did not intentionally include peritumoral edema within the clinical target volume between July 2000 and June 2001. All 48 patients have subsequently recurred, and their original treatment planning parameters were used for this study. New theoretical radiation treatment plans were created for the same 48 patients, based on Radiation Therapy Oncology Group (RTOG) target delineation guidelines that specify inclusion of peritumoral edema. Target volume and recurrent tumor coverage, as well as percent volume of normal brain irradiated, were assessed for both methods of target delineation using dose-volume histograms. Results: A comparison between the location of recurrent tumor and peritumoral edema volumes from all 48 cases failed to show correlation by linear regression modeling (r 2 0.0007; p = 0.3). For patients with edema >75 cm 3 , the percent volume of brain irradiated to 46 Gy was significantly greater in treatment plans that intentionally included peritumoral edema compared with those that did not (38% vs. 31%; p = 0.003). The pattern of failure was identical between the two sets of plans (40 central, 3 in-field, 3 marginal, and 2 distant recurrence). Conclusion: Clinical target volume delineation based on a 2-cm margin rather than on peritumoral edema did not seem to alter the central pattern of failure for patients with GBM. For patients with peritumoral edema >75 cm 3 , using a constant 2-cm margin resulted in a smaller median percent volume of brain being irradiated to 30 Gy, 46 Gy, and 50 Gy compared with corresponding theoretical RTOG plans that deliberately included peritumoral edema

Targeted radiotherapy of osteosarcoma using {sup 153}Sm-EDTMP. A new promising approach

Energy Technology Data Exchange (ETDEWEB)

Bruland, Oe.S. [Dept. of Medical Oncology and Radiotherapy, Norwegian Radium Hospital, Oslo (Norway); Skretting, A. [Dept. of Medical Physics and Technology, Norwegian Radium Hospital, Oslo (Norway); Solheim, Oe.P. [Dept. of Medical Oncology and Radiotherapy, Norwegian Radium Hospital, Oslo (Norway); Aas, M. [Dept. of Nuclear Medicine, Norwegian Radium Hospital, Oslo (Norway)

1996-10-01

We report a case where targeted radionuclide therapy using {sup 153}Sm-EDTMP gave substantial palliative effect. A 35-year-old male with a primary osteosarcoma located in the first lumbar vertebra relapsed with progressive back pain after conventional treatment modalities had failed. He became bedridden, and developed paraparesis and impaired bladder function. On a diagnostic bone-scan intense radioactivity was localized in the tumor. He therefore was given {sup 153}Sm-EDTMP treatment twice, 8 weeks apart, 35 and 32 MBq/kg body weight respectively. After a few days the pain was significantly relieved and by the second radionuclide treatment the pareses subsided. For six months he was able to be up and about without any neurological signs or detectable metastases. Eventually, however, he experienced increasing local pain, developed paraparesis, was re-operated but died 4 months later. The dramatic transient improvement observed in this case warrants further exploration using {sup 153}Sm-EDTMP as a boost technique, supplementary to conventiontal external radiotherapy. (orig.).

Computation of mean and variance of the radiotherapy dose for PCA-modeled random shape and position variations of the target.

Science.gov (United States)

Budiarto, E; Keijzer, M; Storchi, P R M; Heemink, A W; Breedveld, S; Heijmen, B J M

2014-01-20

Radiotherapy dose delivery in the tumor and surrounding healthy tissues is affected by movements and deformations of the corresponding organs between fractions. The random variations may be characterized by non-rigid, anisotropic principal component analysis (PCA) modes. In this article new dynamic dose deposition matrices, based on established PCA modes, are introduced as a tool to evaluate the mean and the variance of the dose at each target point resulting from any given set of fluence profiles. The method is tested for a simple cubic geometry and for a prostate case. The movements spread out the distributions of the mean dose and cause the variance of the dose to be highest near the edges of the beams. The non-rigidity and anisotropy of the movements are reflected in both quantities. The dynamic dose deposition matrices facilitate the inclusion of the mean and the variance of the dose in the existing fluence-profile optimizer for radiotherapy planning, to ensure robust plans with respect to the movements.

Computation of mean and variance of the radiotherapy dose for PCA-modeled random shape and position variations of the target

International Nuclear Information System (INIS)

Budiarto, E; Keijzer, M; Heemink, A W; Storchi, P R M; Breedveld, S; Heijmen, B J M

2014-01-01

Radiotherapy dose delivery in the tumor and surrounding healthy tissues is affected by movements and deformations of the corresponding organs between fractions. The random variations may be characterized by non-rigid, anisotropic principal component analysis (PCA) modes. In this article new dynamic dose deposition matrices, based on established PCA modes, are introduced as a tool to evaluate the mean and the variance of the dose at each target point resulting from any given set of fluence profiles. The method is tested for a simple cubic geometry and for a prostate case. The movements spread out the distributions of the mean dose and cause the variance of the dose to be highest near the edges of the beams. The non-rigidity and anisotropy of the movements are reflected in both quantities. The dynamic dose deposition matrices facilitate the inclusion of the mean and the variance of the dose in the existing fluence-profile optimizer for radiotherapy planning, to ensure robust plans with respect to the movements. (paper)

Proceedings of 19. symposium on experimental radiotherapy and clinical radiobiology

International Nuclear Information System (INIS)

Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemann, H. Peter; Zips, Daniel

2010-01-01

The proceedings include review contributions on radio-oncology, and new radiation technologies and molecular prediction; and poster sessions on the following topics: hypoxia; molecular mechanisms of radiation resistance; molecular targeting; DNA repair; biological imaging; biology of experimental radiations; normal tissue toxicity; modern radiotherapy; tumor hypoxia and metabolic micro milieu; immune system and radiotherapy.

Targeting the bone marrow: applications in stem cell transplantation

International Nuclear Information System (INIS)

Orchard, K.; Cooper, M.

2004-01-01

Therapeutic doses of radiation cab be selectively directed to the bone marrow either directly using vectors that bind to myeloid and/or lymphoid specific antigens or indirectly by targeting bone matrix. The combination of an accessible target tissue and relatively radiation sensitive malignant cells favours the use of targeted radiotherapy in the treatment of haematopoietic malignancies. Dose escalation of targeted radiation can increase tumour cell destruction and has led to the use of myelosuppressive and possibly myeloablative doses of targeted radiation. A natural development has been the use of targeted radiation in conditioning prior to haematopoietic stem cell transplantation (HSCT). Several groups are actively exploring the use of targeted radiotherapy in the context of HSCT as treatment for haematological malignancies. Although no randomised trials using targeted radiotherapy in HSCT have been published, phase I and II trials have shown very encouraging results stimulating further clinical research in this field. After more than a decade of translational research the optimal combination of therapeutic radioisotope and vector has not been determined. This review summarises the clinical experience of targeted radiotherapy in HSCT and discusses the problems that still need to be solved to maximise the potential of this new treatment modality in HSCT

Radiotherapy in primary cerebral lymphoma

International Nuclear Information System (INIS)

Legros, L.; Benezery, K.; Lagrange, J.L.

1999-01-01

Primary cerebral lymphoma is a rare disease with an unfavorable prognosis. Whole brain radiotherapy has been the standard treatment, but neither the optimal radiation fields nor optimal dose level of the regimen are as yet firmly establisheD. From this review of the literature, it seems that the whole brain must be treated, and a boost to the area of the primary site must be discussed. With regard to dose, the radiation dose-response relationship is not clearly proven. Yet, a minimum dose of 40 Gy is necessary, and the maximum dose is set at 50 Gy because of late neurological sequelae. Because of the poor prognosis of this disease and the risk of late sequelae, other avenues have been explored. Chemotherapy has been studied, seem to have a survival advantage and combinations of radiotherapy and chemotherapy, especially with high-dose methotrexate. Because primary cerebral lymphoma is an uncommon disease, randomized clinical trials that compare radiotherapy alone to chemotherapy plus radiotherapy may not be feasible. Finally, even if chemotherapy seems to have a survival advantage, the regimen of chemotherapy is still a matter of debate. (authors)

Stereotactic Radiotherapy of Primary Lung Cancer and Other Targets: Results of Consultant Meeting of the International Atomic Energy Agency

International Nuclear Information System (INIS)

Nagata, Yasushi; Wulf, Joern; Lax, Ingmar; Timmerman, Robert; Zimmermann, Frank; Stojkovski, Igor; Jeremic, Branislav

2011-01-01

To evaluate the current status of stereotactic body radiotherapy (SBRT) and identify both advantages and disadvantages of its use in developing countries, a meeting composed of consultants of the International Atomic Energy Agency was held in Vienna in November 2006. Owing to continuous developments in the field, the meeting was extended by subsequent discussions and correspondence (2007-2010), which led to the summary presented here. The advantages and disadvantages of SBRT expected to be encountered in developing countries were identified. The definitions, typical treatment courses, and clinical results were presented. Thereafter, minimal methodology/technology requirements for SBRT were evaluated. Finally, characteristics of SBRT for developing countries were recommended. Patients for SBRT should be carefully selected, because single high-dose radiotherapy may cause serious complications in some serial organs at risk. Clinical experiences have been reported in some populations of lung cancer, lung oligometastases, liver cancer, pancreas cancer, and kidney cancer. Despite the disadvantages expected to be experienced in developing countries, SBRT using fewer fractions may be useful in selected patients with various extracranial cancers with favorable outcome and low toxicity.

Intra-fraction motion of larynx radiotherapy

Science.gov (United States)

Durmus, Ismail Faruk; Tas, Bora

2018-02-01

In early stage laryngeal radiotherapy, movement is an important factor. Thyroid cartilage can move from swallowing, breathing, sound and reflexes. The effects of this motion on the target volume (PTV) during treatment were examined. In our study, the target volume movement during the treatment for this purpose was examined. Thus, setup margins are re-evaluated and patient-based PTV margins are determined. Intrafraction CBCT was scanned in 246 fractions for 14 patients. During the treatment, the amount of deviation which could be lateral, vertical and longitudinal axis was determined. ≤ ± 0.1cm deviation; 237 fractions in the lateral direction, 202 fractions in the longitudinal direction, 185 fractions in the vertical direction. The maximum deviation values were found in the longitudinal direction. Intrafraction guide in laryngeal radiotherapy; we are sure of the correctness of the treatment, the target volume is to adjust the margin and dose more precisely, we control the maximum deviation of the target volume for each fraction. Although the image quality of intrafraction-CBCT scans was lower than the image quality of planning CT, they showed sufficient contrast for this work.

Rationale and development of image-guided intensity-modulated radiotherapy post-prostatectomy: the present standard of care?

Directory of Open Access Journals (Sweden)

Murray JR

2015-11-01

Full Text Available Julia R Murray,1,2 Helen A McNair,2 David P Dearnaley1,2 1Academic Urology Unit, Institute of Cancer Research, London, 2Department of Radiotherapy, The Royal Marsden NHS Foundation Trust, Sutton, UK Abstract: The indications for post-prostatectomy radiotherapy have evolved over the last decade, although the optimal timing, dose, and target volume remain to be well defined. The target volume is susceptible to anatomical variations with its borders interfacing with the rectum and bladder. Image-guided intensity-modulated radiotherapy has become the gold standard for radical prostate radiotherapy. Here we review the current evidence for image-guided techniques with intensity-modulated radiotherapy to the prostate bed and describe current strategies to reduce or account for interfraction and intrafraction motion. Keywords: radiotherapy, prostate cancer, post-prostatectomy, image-guided radiation therapy

The history and evolution of radiotherapy and radiation oncology in Austria

International Nuclear Information System (INIS)

Kogelnik, H. Dieter

1996-01-01

Austria has a longstanding and eventful history in the field of radiotherapy and radiation oncology. The founder of radiotherapy, Leopold Freund, began his well-documented first therapeutic irradiation on November 24, 1896, in Vienna. He also wrote the first textbook of radiotherapy in 1903. Further outstanding Viennese pioneers in the fields of radiotherapy, radiobiology, radiation physics, and diagnostic radiology include Gottwald Schwarz, Robert Kienboeck, and Guido Holzknecht. Because many of the leading Austrian radiologists had to emigrate in 1938, irreparable damage occurred at that time for the medical speciality of radiology. After World War II, the recovery in the field of radiotherapy and radiation oncology started in Austria in the early sixties. Eleven radiotherapy centers have been established since that time, and an independent society for radio-oncology, radiobiology, and medical radiophysics was founded in 1984. Finally, in March 1994, radiotherapy-radio-oncology became a separate clinical speciality

Investigation on effect of image lag in fluoroscopic images obtained with a dynamic flat-panel detector (FPD) on accuracy of target tracking in radiotherapy

International Nuclear Information System (INIS)

Tanaka, Rie; Ichikawa, Katsuhiro; Sanada, Sigeru; Mori, Shinichiro; Dobashi, Suguru; Kumagai, Motoki; Minohara, Shinichi; Kawashima, Hiroki

2010-01-01

Real-time tumor tracking in external radiotherapy can be achieved by diagnostic (kV) X-ray imaging with a dynamic flat-panel detector (FPD). The purpose of this study was to address image lag in target tracking and its influence on the accuracy of tumor tracking. Fluoroscopic images were obtained using a direct type of dynamic FPD. Image lag properties were measured without test devices according to IEC 62220-1. Modulation transfer function (MTF) and profile curves were measured on the edges of a moving tungsten plate at movement rate of 10 and 20 mm/s, covering lung tumor movement of normal breathing. A lung tumor and metal sphere with blurred edge due to image lag was simulated using the results and then superimposed on breathing chest radiographs of a patient. The moving target with and without image lag was traced using a template-matching technique. In the results, the image lag for the first frame after X-ray cutoff was 2.0% and decreased to less than 0.1% in the fifth frame. In the measurement of profile curves on the edges of static and moving tungsten material plates, the effect of image lag was seen as blurred edges of the plate. The blurred edges of a moving target were indicated as reduction of MTF. However, the target could be traced within an error of ±5 mm. The results indicated that there was no effect of image lag on target tracking in usual breathing speed in a radiotherapy situation. (author)

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

NARCIS (Netherlands)

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

2014-01-01

This report, compiled by experts on the treatment of mobile targets with advanced radiotherapy, summarizes the main conclusions and innovations achieved during the 4D treatment planning workshop 2013. This annual workshop focuses on research aiming to advance 4D radiotherapy treatments, including

Neurovascular bundle–sparing radiotherapy for prostate cancer using MRI-CT registration: A dosimetric feasibility study

Energy Technology Data Exchange (ETDEWEB)

Cassidy, R.J., E-mail: richardjcassidy@emory.edu [Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA (United States); Yang, X.; Liu, T.; Thomas, M. [Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA (United States); Nour, S.G. [Department of Radiology, Emory University, Atlanta, GA (United States); Jani, A.B. [Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA (United States)

2016-01-01

Purpose: Sexual dysfunction after radiotherapy for prostate cancer remains an important late adverse toxicity. The neurovascular bundles (NVB) that lie posterolaterally to the prostate are typically spared during prostatectomy, but in traditional radiotherapy planning they are not contoured as an organ-at-risk with dose constraints. Our goal was to determine the dosimetric feasibility of “NVB-sparing” prostate radiotherapy while still delivering adequate dose to the prostate. Methods: Twenty-five consecutive patients with prostate cancer (with no extraprostatic disease on pelvic magnetic resonance imaging [MRI]) who that were treated with external beam radiotherapy, with the same primary planning target volume margins, to a dose of 79.2 Gy were evaluated. Pelvic MRI and simulation computed tomography scans were registered using dedicated software to allow for bilateral NVB target delineation on T2-weighted MRI. A volumetric modulated arc therapy plan was generated using the NVB bilaterally with 2 mm margin as an organ to spare and compared to the patient’s previously delivered plan. Dose-volume histogram endpoints for NVB, rectum, bladder, and planning target volume 79.2 were compared between the 2 plans using a 2-tailed paired t-test. Results: The V70 for the NVB was significantly lower on the NVB-sparing plan (p <0.01), while rectum and bladder endpoints were similar. Target V100% was similar but V{sub 105%} was higher for the NVB-sparing plans (p <0.01). Conclusions: “NVB-sparing” radiotherapy is dosimetrically feasible using CT-MRI registration, and for volumetric modulated arc therapy technology — target coverage is acceptable without increased dose to other normal structures, but with higher target dose inhomogeneity. The clinical impact of “NVB-sparing” radiotherapy is currently under study at our institution.

Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

Energy Technology Data Exchange (ETDEWEB)

De Wagter, C [ed.

1995-12-01

The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions.

Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

International Nuclear Information System (INIS)

De Wagter, C.

1995-12-01

The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions

Experimental radiotherapy and clinical radiobiology. Vol. 20. Proceedings; Experimentelle Strahlentherapie und Klinische Strahlenbiologie. Bd. 20. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemannn, Hans-Peter; Zips, Daniel (eds.)

2011-07-01

The proceedings include contributions on the following issues: laser driven proton accelerators on the way for radiotherapy, radiobiological evaluation of new radiations; molecular factors of radiation response; biological targeting; EGFR epidermal growth factor receptor/targeting - combined internal and external irradiation, radiobiology of normal tissues; dose-volume histograms for the radiotherapy: curves without radiobiological relevance or important information for the therapy planning; HPV (human papilloma virus) and radiation sensitivity of HNSCC (head and neck squamous cell carcinomas): evidence, radiobiological mechanism, clinical consequences and perspectives; mechanisms of action and intertumoral heterogeneity of response to EGFR inhibition in radiotherapy of solid tumors; evaluation of biomarkers for radiotherapy.

Spatial aspects of combined modality radiotherapy

International Nuclear Information System (INIS)

Bodey, Rachel K.; Evans, Phil M.; Flux, Glenn D.

2005-01-01

Background and purpose: A combined modality radiotherapy (CMRT) incorporates both external beam radiotherapy (EBT) and targeted radionuclide therapy (TRT) components. The spatial aspects of this combination were explored by utilising intensity modulated radiotherapy (IMRT) to provide a non-uniform EBT dose distribution. Patients and methods: Three methods of prescribing the required non-uniform distribution of EBT dose are described, based on both physical and biological criteria according to the distribution of TRT uptake. The results and consequences of these prescriptions are explored by application to three examples of patient data. Results: The planning procedure adopted allowed IMRT plans to be produced that met the prescription requirements. However, when the treatment was planned as a CMRT, compared with the use of EBT alone, more satisfactory target doses could be achieved with lower doses to normal tissues. The effects of errors in EBT delivery and in the functional data were found to cause a non-uniform prescription to tend towards the uniform case. Conclusions: The methods and results are relevant for more general biological treatment planning, in which IMRT may be used to produce dose distributions prescribed according to tumour function. The effects of delivery and dose calculation errors can have a significant impact on how such treatments should be planned

Multileaf collimator in radiotherapy

International Nuclear Information System (INIS)

Jeraj, M.; Robar, V.

2004-01-01

Background. Basic goal of radiotherapy treatment is the irradiation of a target volume while minimizing the amount of radiation absorbed in healthy tissue. Shaping the beam is an important way of minimizing the absorbed dose in healthy tissue and critical structures. Conventional collimator jaws are used for shaping a rectangular treatment field; but, as usually treatment volume is not rectangular, additional shaping is required. On a linear accelerator, lead blocks or individually made Cerroben TM blocks are attached onto the treatment head under standard collimating system. Another option is the use of multileaf collimator (MLC). Conclusions. Multileaf collimator is becoming the main tool for beam shaping on the linear accelerator. It is a simple and useful system in the preparation and performance of radiotherapy treatment. Multileaf collimators are reliable, as their manufacturers developed various mechanisms for their precision, control and reliability, together with reduction of leakage and transmission of radiation between and through the leaves. Multileaf collimator is known today as a very useful clinical system for simple field shaping, but its use is getting even more important in dynamic radiotherapy, with the leaves moving during irradiation. This enables a precise dose delivery on any part of a treated volume. Intensity modulated radiotherapy (IMRT), the therapy of the future, is based on the dynamic use of MLC. (author)

Pattern of relapse in surgical treated patients with thoracic esophageal squamous cell carcinoma and its possible impact on target delineation for postoperative radiotherapy

International Nuclear Information System (INIS)

Cai Wenjie; Xin Peiling

2010-01-01

Objective: To provide a reference for determination of the postoperative radiotherapy target volume for thoracic esophageal squamous cell carcinoma. Background data: The irradiation target volume is important for effective postoperative treatment of thoracic esophageal squamous cell carcinoma. Methods: One hundred forty patients with recurrent or metastatic thoracic esophageal squamous cell carcinoma who had been treated with radical surgery but not with postoperative radiotherapy were enrolled in this study. The information of locoregional recurrence and distant metastasis for these patients was analyzed. Results: The median time to progression in the 140 patients with recurrence or metastasis was 18.3 months (range 15.4-21.1 months). Anastomotic recurrence accounted for 13.6% of treatment failures. The supraclavicular and station 1-5 and 7 lymph nodes had high metastasis rates for esophageal squamous cell carcinomas in all locations. The order from highest to lowest metastasis rate for the station 3 and 4 lymph nodes was middle, upper and lower thoracic esophageal regions and the order for upper abdominal lymph nodes was lower, middle, and upper thoracic esophageal regions. Locoregional recurrence was the most common type of recurrence. Conclusions: For upper and middle thoracic esophageal squamous cell carcinomas, the anastomosis, supraclavicular, and station 1-5 and 7 lymph nodes should be delineated as the postoperative prophylactic irradiation target volume with upper abdominal lymph nodes excluded; for lower thoracic esophageal squamous cell carcinomas, anastomosis, supraclavicular, station 1-5 and 7 lymph nodes and upper abdominal lymph nodes should be delineated as the postoperative prophylactic irradiation target volume.

Multi-isocenter stereotactic radiotherapy: implications for target dose distributions of systematic and random localization errors

International Nuclear Information System (INIS)

Ebert, M.A.; Zavgorodni, S.F.; Kendrick, L.A.; Weston, S.; Harper, C.S.

2001-01-01

Purpose: This investigation examined the effect of alignment and localization errors on dose distributions in stereotactic radiotherapy (SRT) with arced circular fields. In particular, it was desired to determine the effect of systematic and random localization errors on multi-isocenter treatments. Methods and Materials: A research version of the FastPlan system from Surgical Navigation Technologies was used to generate a series of SRT plans of varying complexity. These plans were used to examine the influence of random setup errors by recalculating dose distributions with successive setup errors convolved into the off-axis ratio data tables used in the dose calculation. The influence of systematic errors was investigated by displacing isocenters from their planned positions. Results: For single-isocenter plans, it is found that the influences of setup error are strongly dependent on the size of the target volume, with minimum doses decreasing most significantly with increasing random and systematic alignment error. For multi-isocenter plans, similar variations in target dose are encountered, with this result benefiting from the conventional method of prescribing to a lower isodose value for multi-isocenter treatments relative to single-isocenter treatments. Conclusions: It is recommended that the systematic errors associated with target localization in SRT be tracked via a thorough quality assurance program, and that random setup errors be minimized by use of a sufficiently robust relocation system. These errors should also be accounted for by incorporating corrections into the treatment planning algorithm or, alternatively, by inclusion of sufficient margins in target definition

Protocol updated for the treatment of patients in radiotherapy with implanted cardiac devices

International Nuclear Information System (INIS)

Martin Martin, G.; Bermudez Luna, R.; Rodriguez Rodriguez, C.; Lopez Fernandez, A.; Rodriguez Perez, A.; Sotoca Ruiz, A.

2013-01-01

Radiotherapy treatment can be safely performed in patients with pacemakers or implanted defibrillators, however, it is very important to ensure that the patient receives the minimum dose possible in your heart device. Is considered essential good coordination with the cardiology service before, during and after radiotherapy treatment for the patient safety. Finally we present a protocol updated to treat these patients in radiotherapy. (Author)

Co-targeting androgen receptor and DNA for imaging and molecular radiotherapy of prostate cancer: in vitro studies.

Science.gov (United States)

Han, Guang; Kortylewicz, Zbigniew P; Enke, Thomas; Baranowska-Kortylewicz, Janina

2014-12-01

The androgen receptor (AR) axis, the key growth and survival pathway in prostate cancer, remains a prime target for drug development. 5-Radioiodo-3'-O-(17β-succinyl-5α-androstan-3-one)-2'-deoxyuridin-5'-yl phosphate (RISAD-P) is the AR-seeking reagent developed for noninvasive assessment of AR and proliferative status, and for molecular radiotherapy of prostate cancer with Auger electron-emitting radionuclides. RISAD-P radiolabeled with 123I, 124I, and 125I were synthesized using a common stannylated precursor. The cellular uptake, subcellular distribution, and radiotoxicity of 123I-, 124I-, and (125) IRISAD-P were measured in LNCaP, DU145, and PC-3 cell lines expressing various levels of AR. The uptake of RISAD-P by prostate cancer cells is proportional to AR levels and independent of the radionuclide. The intracellular accumulation of radioactivity is directly proportional to the extracellular concentration of RISAD-P and the duration of exposure. Initially, RISAD-P is trapped in the cytoplasm. Within 24 hr, radioactivity is associated exclusively with DNA. The RISAD-P radiotoxicity is determined by the radionuclide; however, the cellular responses are directly proportional to the AR expression levels. LNCaP cells expressing high levels of AR are killed at the rate of up to 60% per day after a brief 1 hr RISAD-P treatment. For the first time, the AR expression in PC-3 and DU 145 cells, generally reported as AR-negative, was quantitated by the ultra sensitive RISAD-P-based method. RISAD-P is a theranostic drug, which targets AR. Its subcellular metabolite participates in DNA synthesis. RISAD-P is a promising candidate for imaging of the AR expression and tumor proliferation as well as molecular radiotherapy of prostate cancer. © 2014 Wiley Periodicals, Inc.

Cardiac dose estimates from Danish and Swedish breast cancer radiotherapy during 1977-2001

International Nuclear Information System (INIS)

Taylor, Carolyn W.; Bronnum, Dorthe; Darby, Sarah C.; Gagliardi, Giovanna; Hall, Per; Jensen, Maj-Britt; McGale, Paul; Nisbet, Andrew; Ewertz, Marianne

2011-01-01

Background and purpose: To estimate target and cardiac doses from breast cancer radiotherapy in Denmark and in the Stockholm and Umea areas of Sweden during 1977-2001. Methods: Representative samples of irradiated women were identified from the databases of the Danish Breast Cancer Cooperative Group and the Swedish Nationwide Cancer Registry. Virtual simulation, computed tomography planning and manual planning were used to reconstruct radiotherapy regimens on a typical woman. Estimates of target dose and various measures of cardiac dose were derived from individual radiotherapy charts. Results: Doses were estimated in 681 Danish and 130 Swedish women. Mean heart dose for individual women varied from 1.6 to 14.9 Gray in Denmark and from 1.2 to 22.1 Gray in Sweden. In Denmark, mean target doses averaged across women increased from 40.6 to 53.8 Gray during 1977-2001 but, despite this, mean heart dose averaged across women remained around 6 Gy for left-sided and 2-3 Gray for right-sided radiotherapy. In Sweden mean target dose averaged across women increased from 38.7 to 46.6 Gray during 1977-2001, while mean heart dose averaged across women decreased from 12.0 to 7.3 Gray for left-sided and from 3.6 to 3.2 Gray for right-sided radiotherapy. Temporal trends for mean biologically effective dose [BED] to the heart, mean dose to the left anterior descending coronary artery, the right coronary artery and the circumflex coronary artery were broadly similar. Conclusions: Cardiac doses in Denmark were low relative to those in Sweden. In both countries, target dose increased during 1977-2001. Despite this, cardiac doses remained constant in Denmark and decreased in Sweden.

The potential advantages of (18)FDG PET/CT-based target volume delineation in radiotherapy planning of head and neck cancer.

Science.gov (United States)

Moule, Russell N; Kayani, Irfan; Moinuddin, Syed A; Meer, Khalda; Lemon, Catherine; Goodchild, Kathleen; Saunders, Michele I

2010-11-01

This study investigated two fixed threshold methods to delineate the target volume using (18)FDG PET/CT before and during a course of radical radiotherapy in locally advanced squamous cell carcinoma of the head and neck. Patients were enrolled into the study between March 2006 and May 2008. (18)FDG PET/CT scans were carried out 72h prior to the start of radiotherapy and then at 10, 44 and 66Gy. Functional volumes were delineated according to the SUV Cut Off (SUVCO) (2.5, 3.0, 3.5, and 4.0bwg/ml) and percentage of the SUVmax (30%, 35%, 40%, 45%, and 50%) thresholds. The background (18)FDG uptake and the SUVmax within the volumes were also assessed. Primary and lymph node volumes for the eight patients significantly reduced with each increase in the delineation threshold (for example 2.5-3.0bwg/ml SUVCO) compared to the baseline threshold at each imaging point. There was a significant reduction in the volume (p⩽0.0001-0.01) after 36Gy compared to the 0Gy by the SUVCO method. There was a negative correlation between the SUVmax within the primary and lymph node volumes and delivered radiation dose (p⩽0.0001-0.011) but no difference in the SUV within the background reference region. The volumes delineated by the PTSUVmax method increased with the increase in the delivered radiation dose after 36Gy because the SUVmax within the region of interest used to define the edge of the volume was equal or less than the background (18)FDG uptake and the software was unable to effectively differentiate between tumour and background uptake. The changes in the target volumes delineated by the SUVCO method were less susceptible to background (18)FDG uptake compared to those delineated by the PTSUVmax and may be more helpful in radiotherapy planning. The best method and threshold have still to be determined within institutions, both nationally and internationally. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Multivariate analysis for the estimation of target localization errors in fiducial marker-based radiotherapy

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Takamiya, Masanori [Department of Nuclear Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan and Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507 (Japan); Nakamura, Mitsuhiro, E-mail: m-nkmr@kuhp.kyoto-u.ac.jp; Akimoto, Mami; Ueki, Nami; Yamada, Masahiro; Matsuo, Yukinori; Mizowaki, Takashi; Hiraoka, Masahiro [Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto 606-8507 (Japan); Tanabe, Hiroaki [Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe 650-0047 (Japan); Kokubo, Masaki [Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe 650-0047, Japan and Department of Radiation Oncology, Kobe City Medical Center General Hospital, Kobe 650-0047 (Japan); Itoh, Akio [Department of Nuclear Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan)

2016-04-15

Purpose: To assess the target localization error (TLE) in terms of the distance between the target and the localization point estimated from the surrogates (|TMD|), the average of respiratory motion for the surrogates and the target (|aRM|), and the number of fiducial markers used for estimating the target (n). Methods: This study enrolled 17 lung cancer patients who subsequently underwent four fractions of real-time tumor tracking irradiation. Four or five fiducial markers were implanted around the lung tumor. The three-dimensional (3D) distance between the tumor and markers was at maximum 58.7 mm. One of the markers was used as the target (P{sub t}), and those markers with a 3D |TMD{sub n}| ≤ 58.7 mm at end-exhalation were then selected. The estimated target position (P{sub e}) was calculated from a localization point consisting of one to three markers except P{sub t}. Respiratory motion for P{sub t} and P{sub e} was defined as the root mean square of each displacement, and |aRM| was calculated from the mean value. TLE was defined as the root mean square of each difference between P{sub t} and P{sub e} during the monitoring of each fraction. These procedures were performed repeatedly using the remaining markers. To provide the best guidance on the answer with n and |TMD|, fiducial markers with a 3D |aRM ≥ 10 mm were selected. Finally, a total of 205, 282, and 76 TLEs that fulfilled the 3D |TMD| and 3D |aRM| criteria were obtained for n = 1, 2, and 3, respectively. Multiple regression analysis (MRA) was used to evaluate TLE as a function of |TMD| and |aRM| in each n. Results: |TMD| for n = 1 was larger than that for n = 3. Moreover, |aRM| was almost constant for all n, indicating a similar scale for the marker’s motion near the lung tumor. MRA showed that |aRM| in the left–right direction was the major cause of TLE; however, the contribution made little difference to the 3D TLE because of the small amount of motion in the left–right direction. The TLE

Intraoperative Radiotherapy for Breast Cancer

Directory of Open Access Journals (Sweden)

Eleanor E. R. Harris

2017-12-01

Full Text Available Intraoperative radiotherapy (IORT for early stage breast cancer is a technique for partial breast irradiation. There are several technologies in clinical use to perform breast IORT. Regardless of technique, IORT generally refers to the delivery of a single dose of radiation to the periphery of the tumor bed in the immediate intraoperative time frame, although some protocols have performed IORT as a second procedure. There are two large prospective randomized trials establishing the safety and efficacy of breast IORT in early stage breast cancer patients with sufficient follow-up time on thousands of women. The advantages of IORT for partial breast irradiation include: direct visualization of the target tissue ensuring treatment of the high-risk tissue and eliminating the risk of marginal miss; the use of a single dose coordinated with the necessary surgical excision thereby reducing omission of radiation and the selection of mastectomy for women without access to a radiotherapy facility or unable to undergo several weeks of daily radiation; favorable toxicity profiles; patient convenience and cost savings; radiobiological and tumor microenvironment conditions which lead to enhanced tumor control. The main disadvantage of IORT is the lack of final pathologic information on the tumor size, histology, margins, and nodal status. When unexpected findings on final pathology such as positive margins or positive sentinel nodes predict a higher risk of local or regional recurrence, additional whole breast radiation may be indicated, thereby reducing some of the convenience and low-toxicity advantages of sole IORT. However, IORT as a tumor bed boost has also been studied and appears to be safe with acceptable toxicity. IORT has potential efficacy advantages related to overall survival related to reduced cardiopulmonary radiation doses. It may also be very useful in specific situations, such as prior to oncoplastic reconstruction to improve accuracy of

Targeting radiation to tumours

International Nuclear Information System (INIS)

Wheldon, T.E.; Greater Glasgow Health Board, Glasgow

1994-01-01

Biologically targeted radiotherapy entails the preferential delivery of radiation to solid tumours or individual tumour cells by means of tumour-seeking delivery vehicles to which radionuclides can be conjugated. Monoclonal antibodies have attracted attention for some years as potentially selective targeting agents, but advances in tumour and molecular biology are now providing a much wider choice of molecular species. General radiobiological principles may be derived which are applicable to most forms of targeted radiotherapy. These principles provide guidelines for the appropriate choice of radionuclide in specific treatment situations and its optimal combination with other treatment modalities. In future, the availability of gene targeting agents will focus attention on the use of Auger electron emitters whose high potency and short range selectivity makes them attractive choices for specific killing of cancer cells whose genetic peculiarities are known. (author)

Target volume definition for {sup 18}F-FDG PET-positive lymph nodes in radiotherapy of patients with non-small cell lung cancer

Energy Technology Data Exchange (ETDEWEB)

Nestle, Ursula; Schaefer-Schuler, Andrea; Hellwig, Dirk; Kirsch, Carl-Martin [Saarland University Medical Centre, Department of Nuclear Medicine, Homburg/Saar (Germany); Kremp, Stephanie; Ruebe, Christian [Saarland University Medical Centre, Department of Radio-oncology, Homburg/Saar (Germany); Groeschel, Andreas [Saarland University Medical Centre, Department of Pneumology, Homburg/Saar (Germany)

2007-04-15

FDG PET is increasingly used in radiotherapy planning. Recently, we demonstrated substantial differences in target volumes when applying different methods of FDG-based contouring in primary lung tumours (Nestle et al., J Nucl Med 2005;46:1342-8). This paper focusses on FDG-positive mediastinal lymph nodes (LN{sub PET}). In our institution, 51 NSCLC patients who were candidates for radiotherapy prospectively underwent staging FDG PET followed by a thoracic PET scan in the treatment position and a planning CT. Eleven of them had 32 distinguishable non-confluent mediastinal or hilar nodal FDG accumulations (LN{sub PET}). For these, sets of gross tumour volumes (GTVs) were generated at both acquisition times by four different PET-based contouring methods (visual: GTV{sub vis}; 40% SUV{sub max}: GTV{sub 40}; SUV=2.5: GTV{sub 2.5}; target/background (T/B) algorithm: GTV{sub bg}). All differences concerning GTV sizes were within the range of the resolution of the PET system. The detectability and technical delineability of the GTVs were significantly better in the late scans (e.g. p = 0.02 for diagnostic application of SUV{sub max} = 2.5; p = 0.0001 for technical delineability by GTV{sub 2.5}; p = 0.003 by GTV{sub 40}), favouring the GTV{sub bg} method owing to satisfactory overall applicability and independence of GTVs from acquisition time. Compared with CT, the majority of PET-based GTVs were larger, probably owing to resolution effects, with a possible influence of lesion movements. For nodal GTVs, different methods of contouring did not lead to clinically relevant differences in volumes. However, there were significant differences in technical delineability, especially after early acquisition. Overall, our data favour a late acquisition of FDG PET scans for radiotherapy planning, and the use of a T/B algorithm for GTV contouring. (orig.)

Quality assurance in radiotherapy

International Nuclear Information System (INIS)

2003-03-01

Good radiotherapy results and safety of treatment require the radiation to be optimally applied to a specified target area and the correct dose. According to international recommendations, the average uncertainty in therapeutic dose should not exceed 5%. The need for high precision in therapeutic dose requires quality assurance covering the entire radiotherapy process. Besides the physical and technical characteristics of the therapy equipment, quality assurance must include all radiotherapy equipment and procedures that are significant for the correct magnitude and precision of application of the therapeutic dose. The duties and responsibilities pertaining to various stages of treatment must also be precisely defined. These requirements may be best implemented through a quality system. The general requirements for supervision and quality assurance of medical radiation apparatus are prescribed in section 40 of the Radiation Act (592/1991, amendment 1142/1998) and in sections 18 and 32 of the Decree of the Ministry of Social Affairs and Health on the medical use of radiation (423/2000). Guide ST 2.2 imposes requirements on structural radiation shielding of radiotherapy equipment and the premises in which it is used, and on warning and safety arrangements. Guide ST 1.1 sets out the general safety principles for radiation practices and regulatory control procedure for the use of radiation. Guide ST 1.6 provides general requirements for operational measures in the use of radiation. This Guide sets out the duties of responsible parties (the party running a radiation practice) in respect of arranging and maintaining radiotherapy quality assurance. The principles set out in this Guide and Guide ST 6.3 may be applied to radionuclide therapy

Influence of the electron energy and number of beams on the absorbed dose distributions in radiotherapy of deep seated targets.

Science.gov (United States)

Garnica-Garza, H M

2014-12-01

With the advent of compact laser-based electron accelerators, there has been some renewed interest on the use of such charged particles for radiotherapy purposes. Traditionally, electrons have been used for the treatment of fairly superficial lesions located at depths of no more than 4cm inside the patient, but lately it has been proposed that by using very high energy electrons, i.e. those with an energy in the order of 200-250MeV it should be possible to safely reach deeper targets. In this paper, we used a realistic patient model coupled with detailed Monte Carlo simulations of the electron transport in such a patient model to examine the characteristics of the resultant absorbed dose distributions as a function of both the electron beam energy as well as the number of beams for a particular type of treatment, namely, a prostate radiotherapy treatment. Each treatment is modeled as consisting of nine, five or three beam ports isocentrically distributed around the patient. An optimization algorithm is then applied to obtain the beam weights in each treatment plan. It is shown that for this particularly challenging case, both excellent target coverage and critical structure sparing can be obtained for energies in the order of 150MeV and for as few as three treatment ports, while significantly reducing the total energy absorbed by the patient with respect to a conventional megavoltage x-ray treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Interest of FDG-PET for lung cancer radiotherapy; Interet de la TEP au FDG pour la radiotherapie des cancers bronchiques

Energy Technology Data Exchange (ETDEWEB)

Thureau, S.; Mezzani-Saillard, S.; Dubray, B. [Departement de radiotherapie et de physique medicale et QuantIF - Litis, EA 4108, CRLCC Henri-Becquerel, 1, rue d' Amiens, 76038 Rouen (France); Modzelewski, R.; Edet-Sanson, A.; Vera, P. [Departement de medecine nucleaire et QuantIF - Litis, EA 4108, CRLCC Henri-Becquerel, 1, rue d' Amiens, 76038 Rouen (France)

2011-10-15

The recent advances in medical imaging have profoundly altered the radiotherapy of non-small cell lung cancers (NSCLC). A meta-analysis has confirmed the superiority of FDG PET-CT over CT for initial staging. FDG PET-CT improves the reproducibility of target volume delineation, especially close to the mediastinum or in the presence of atelectasis. Although not formally validated by a randomized trial, the reduction of the mediastinal target volume, by restricting the irradiation to FDG-avid nodes, is widely accepted. The optimal method of delineation still remains to be defined. The role of FDGPET-CT in monitoring tumor response during radiotherapy is under investigation, potentially opening the way to adapting the treatment modalities to tumor radiation sensitivity. Other tracers, such as F-miso (hypoxia), are also under clinical investigation. To avoid excessive delays, the integration of PET-CT in routine practice requires quick access to the imaging equipment, technical support (fusion and image processing) and multidisciplinary delineation of target volumes. (authors)

Towards multidimensional radiotherapy (MD-CRT): biological imaging and biological conformality

International Nuclear Information System (INIS)

Ling, C. Clifton; Humm, John; Larson, Steven; Amols, Howard; Fuks, Zvi; Leibel, Steven; Koutcher, Jason A.

2000-01-01

Purpose: The goals of this study were to survey and summarize the advances in imaging that have potential applications in radiation oncology, and to explore the concept of integrating physical and biological conformality in multidimensional conformal radiotherapy (MD-CRT). Methods and Materials: The advances in three-dimensional conformal radiotherapy (3D-CRT) have greatly improved the physical conformality of treatment planning and delivery. The development of intensity-modulated radiotherapy (IMRT) has provided the 'dose painting' or 'dose sculpting' ability to further customize the delivered dose distribution. The improved capabilities of nuclear magnetic resonance imaging and spectroscopy, and of positron emission tomography, are beginning to provide physiological and functional information about the tumor and its surroundings. In addition, molecular imaging promises to reveal tumor biology at the genotype and phenotype level. These developments converge to provide significant opportunities for enhancing the success of radiotherapy. Results: The ability of IMRT to deliver nonuniform dose patterns by design brings to fore the question of how to 'dose paint' and 'dose sculpt', leading to the suggestion that 'biological' images may be of assistance. In contrast to the conventional radiological images that primarily provide anatomical information, biological images reveal metabolic, functional, physiological, genotypic, and phenotypic data. Important for radiotherapy, the new and noninvasive imaging methods may yield three-dimensional radiobiological information. Studies are urgently needed to identify genotypes and phenotypes that affect radiosensitivity, and to devise methods to image them noninvasively. Incremental to the concept of gross, clinical, and planning target volumes (GTV, CTV, and PTV), we propose the concept of 'biological target volume' (BTV) and hypothesize that BTV can be derived from biological images and that their use may incrementally improve

Feasibility of CBCT-based target and normal structure delineation in prostate cancer radiotherapy: Multi-observer and image multi-modality study

International Nuclear Information System (INIS)

Luetgendorf-Caucig, Carola; Fotina, Irina; Stock, Markus; Poetter, Richard; Goldner, Gregor; Georg, Dietmar

2011-01-01

Background and purpose: In-room cone-beam CT (CBCT) imaging and adaptive treatment strategies are promising methods to decrease target volumes and to spare organs at risk. The aim of this work was to analyze the inter-observer contouring uncertainties of target volumes and organs at risks (oars) in localized prostate cancer radiotherapy using CBCT images. Furthermore, CBCT contouring was benchmarked against other image modalities (CT, MR) and the influence of subjective image quality perception on inter-observer variability was assessed. Methods and materials: Eight prostate cancer patients were selected. Seven radiation oncologists contoured target volumes and oars on CT, MRI and CBCT. Volumes, coefficient of variation (COV), conformity index (cigen), and coordinates of center-of-mass (COM) were calculated for each patient and image modality. Reliability analysis was performed for the support of the reported findings. Subjective perception of image quality was assessed via a ten-scored visual analog scale (VAS). Results: The median volume for prostate was larger on CT compared to MRI and CBCT images. The inter-observer variation for prostate was larger on CBCT (CIgen = 0.57 ± 0.09, 0.61 reliability) compared to CT (CIgen = 0.72 ± 0.07, 0.83 reliability) and MRI (CIgen = 0.66 ± 0.12, 0.87 reliability). On all image modalities values of the intra-observer reliability coefficient (0.97 for CT, 0.99 for MR and 0.94 for CBCT) indicated high reproducibility of results. For all patients the root mean square (RMS) of the inter-observer standard deviation (σ) of the COM was largest on CBCT with σ(x) = 0.4 mm, σ(y) = 1.1 mm, and σ(z) = 1.7 mm. The concordance in delineating OARs was much stronger than for target volumes, with average CIgen > 0.70 for rectum and CIgen > 0.80 for bladder. Positive correlations between CIgen and VAS score of the image quality were observed for the prostate, seminal vesicles and rectum. Conclusions: Inter-observer variability for target

Comparison of target volumes in radiotherapy defined on scanner and on PET-T.D.M. with {sup 18}F-F.D.G. in the frame of head and neck cancers; Comparaison des volumes cibles en radiotherapie definis sur scanner et sur TEP-TDM au 18F FDG dans le cadre des cancers de la tete et du cou

Energy Technology Data Exchange (ETDEWEB)

Henriques De Figueiredo, B.; Barret, O.; Allard, M.; Fernandez, P. [Service de medecine nucleaire, CHU de Pellegrin, Bordeaux, (France); Demeaux, H.; Maire, J.P.; Lagarde, P. [service de radiotherapie, hopital Saint-Andre, Bordeaux, (France); Kantor, G.; Richau, P. [departement de radiotherapie, institut Bergonie, Bordeaux, (France); De Mones Del Pujol, E. [service d' ORL, hopital Pellegrin, Bordeaux, (France)

2009-05-15

The objective is to study in a prospective way, in the frame of head and neck cancers, the impact of the positron computed tomography with {sup 18}F fluorodeoxyglucose (PET-F.D.G.) on the limitation of target volumes in radiotherapy. In conclusions, the gross tumor volume (G.T.V.) defined on PET is smaller than this one defined on scanner, that could be interesting in radiotherapy, in the perspective of a dose escalation. In addition, areas of discordance exist between the clinical target volumes (C.T.V.70 and C.T.V.50) defined on PET and on scanner. These discordances, synonyms of under or over estimation of target volumes, could have important clinical consequences in term of local control and toxicity. (N.C.)

Credentialing of radiotherapy centres for a clinical trial of adaptive radiotherapy for bladder cancer (TROG 10.01)

International Nuclear Information System (INIS)

Kron, Tomas; Pham, Daniel; Roxby, Paul; Rolfo, Aldo; Foroudi, Farshad

2012-01-01

Background: Daily variations in bladder filling make conformal treatment of bladder cancer challenging. On-line adaptive radiotherapy with a choice of plans has been demonstrated to reduce small bowel irradiation in single institution trials. In order to support a multicentre feasibility clinical trial on adaptive radiotherapy for bladder cancer (TROG 10.01) a credentialing programme was developed for centres wishing to participate. Methods: The credentialing programme entails three components: a facility questionnaire; a planning exercise which tests the ability of centres to create three adaptive plans based on a planning and five cone beam CTs; and a site visit during which image quality, imaging dose and image guidance procedures are assessed. Image quality and decision making were tested using customised inserts for a Perspex phantom (Modus QUASAR) that mimic different bladder sizes. Dose was assessed in the same phantom using thermoluminescence dosimetry (TLD). Results: All 12 centres participating in the full credentialing programme were able to generate appropriate target volumes in the planning exercise and identify the correct target volume and position the bladder phantom in the phantom within 3 mm accuracy. None of the imaging doses exceeded the limit of 5 cGy with a CT on rails system having the lowest overall dose. Conclusion: A phantom mimicking the decision making process for adaptive radiotherapy was found to be well suited during site visits for credentialing of centres participating in a clinical trial of adaptive radiotherapy for bladder cancer. Combined with a planning exercise the site visit allowed testing the ability of centres to create adaptive treatment plans and make appropriate decisions based on the volumetric images acquired at treatment.

Extracranial stereotactic radiotherapy: preliminary results with the CyberKnife.

Science.gov (United States)

Lartigau, Eric; Mirabel, Xavier; Prevost, Bernard; Lacornerie, Thomas; Dubus, Francois; Sarrazin, Thierry

2009-04-01

In the field of radiation oncology, equipment for fractionated radiotherapy and single-dose radiosurgery has become increasingly accurate, together with the introduction of robotized treatments. A robot is a device that can be programmed to carry out accurate, repeated and adjusted tasks in a given environment. Treatment of extracranial lesions involves taking into account organ mobility (tumor and healthy tissue) whilst retaining the ability to stereotactically locate the target. New imaging techniques (single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), positron emission tomography (PET)) provide further relevant information to slice images (computed tomography (CT) scans, MRI) for target definition. Hypo-fractionated treatments can only be used for curative treatment if the target is accurately defined and tracked during treatment. The CyberKnife is a non-invasive system of radiosurgery and fractionated stereotactic radiotherapy. For intracranial lesions treated by single-dose radiosurgery, it has been used to treat meningioma, acoustic neuromas, pituitary adenoma, metastases, arteriovenous malformations and refractory pain (trigeminal neuralgia). More than 10,000 patients have been treated worldwide. Currently, the most significant developments are in the field of extracranial stereotactic radiotherapy (lung, liver, reirradiation, prostate, etc.). Clinical results obtained in the CyberKnife Nord-Ouest program after 1 year of experience are presented. Copyright 2009 S. Karger AG, Basel.

Parotid gland sparing radiotherapy technique using 3-D conformal radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Lim, Ji Hoon; Kim, Gwi Eon; Keum, Ki Chang; Suh, Chang Ok; Lee, Sang Wook; Park, Hee Chul; Cho, Jae Ho; Chang, Sei Kyung; Loh, Juhn Kyu

2000-01-01

Although using the high energy photon beam with conventional parallel-opposed beams radio-therapy for nasopgaryngeal carcinoma, radiation-induced xerostomia is a troublesome problem for patients. We conducted this study to explore a new parotid gland sparing technique in 3-D conformal radiotherapy (3-DCRT) in an effort to prevent the radiation-induced xerostomia. We performed three different planning for four clinically node-negative nasopharyngeal cancer patients with different location of tumor(intracranial extension, nasal cavity extension, oropharyngeal extension, parapharyngeal extension), and intercompared the plans. Total prescription dose was 70.2 Gy to the isocenter. For plan-A, 2-D parallel opposing fields, a conventional radiotherapy technique, were employed. For plan-B, 2-D parallel opposing fields were used up until 54 Gy and afterwards 3-D non-coplanar beams were used. For plan-C, the new technique, 54Gy was delivered by 3-D conformal 3-port beams (AP and both lateral ports with wedge compensator, shielding both superficial lobes of parotid glands at the AP beam using BEV) from the beginning of the treatment and early spinal cord block (at 36 Gy) was performed. And bilateral posterior necks were treated with electron after 36 Gy. After 54 Gy, non-coplanar beams were used for cone-down plan. We intercompared dose statistics (Dmax, Dmin, Dmean, D95, D05, V95, V05, Volume receiving 46 Gy) and dose volume histograms (DVH) of tumor and normal tissues and NTCP values of parotid glands for the above three plans. For all patients, the new technique (plan-C) was comparable or superior to the other plans in target volume isodose distribution and dose statistics and it has more homogenous target volume coverage. The new technique was most superior to the other plans in parotid glands sparing (volume receiving 46 Gy: 100, 98, 69% for each plan-A, B and C). And it showed the lowest NTCP value of parotid glands in all patients (range of NTCP; 96-100%, 79-99%, 51

A dose-volume histogram based decision-support system for dosimetric comparison of radiotherapy treatment plans

International Nuclear Information System (INIS)

Alfonso, J. C. L.; Herrero, M. A.; Núñez, L.

2015-01-01

The choice of any radiotherapy treatment plan is usually made after the evaluation of a few preliminary isodose distributions obtained from different beam configurations. Despite considerable advances in planning techniques, such final decision remains a challenging task that would greatly benefit from efficient and reliable assessment tools. For any dosimetric plan considered, data on dose-volume histograms supplied by treatment planning systems are used to provide estimates on planning target coverage as well as on sparing of organs at risk and the remaining healthy tissue. These partial metrics are then combined into a dose distribution index (DDI), which provides a unified, easy-to-read score for each competing radiotherapy plan. To assess the performance of the proposed scoring system, DDI figures for fifty brain cancer patients were retrospectively evaluated. Patients were divided in three groups depending on tumor location and malignancy. For each patient, three tentative plans were designed and recorded during planning, one of which was eventually selected for treatment. We thus were able to compare the plans with better DDI scores and those actually delivered. When planning target coverage and organs at risk sparing are considered as equally important, the tentative plan with the highest DDI score is shown to coincide with that actually delivered in 32 of the 50 patients considered. In 15 (respectively 3) of the remaining 18 cases, the plan with highest DDI value still coincides with that actually selected, provided that organs at risk sparing is given higher priority (respectively, lower priority) than target coverage. DDI provides a straightforward and non-subjective tool for dosimetric comparison of tentative radiotherapy plans. In particular, DDI readily quantifies differences among competing plans with similar-looking dose-volume histograms and can be easily implemented for any tumor type and localization, irrespective of the planning system and

Radiotherapy

International Nuclear Information System (INIS)

Prosnitz, L.R.; Kapp, D.S.; Weissberg, J.B.

1983-01-01

This review highlights developments over the past decade in radiotherapy and attempts to summarize the state of the art in the management of the major diseases in which radiotherapy has a meaningful role. The equipment, radiobiology of radiotherapy and carcinoma of the lung, breast and intestines are highlighted

Fractionated stereotactic radiotherapy boost for gynecologic tumors: An alternative to brachytherapy?

International Nuclear Information System (INIS)

Molla, Meritxell; Escude, Lluis D.; Nouet, Philippe; Popowski, Youri D.Sc.; Hidalgo, Alberto; Rouzaud, Michel; Linero, Dolores; Miralbell, Raymond

2005-01-01

Purpose: A brachytherapy (BT) boost to the vaginal vault is considered standard treatment for many endometrial or cervical cancers. We aimed to challenge this treatment standard by using stereotactic radiotherapy (SRT) with a linac-based micromultileaf collimator technique. Methods and Materials: Since January 2002, 16 patients with either endometrial (9) or cervical (7) cancer have been treated with a final boost to the areas at higher risk for relapse. In 14 patients, the target volume included the vaginal vault, the upper vagina, the parametria, or (if not operated) the uterus (clinical target volume [CTV]). In 2 patients with local relapse, the CTV was the tumor in the vaginal stump. Margins of 6-10 mm were added to the CTV to define the planning target volume (PTV). Hypofractionated dynamic-arc or intensity-modulated radiotherapy techniques were used. Postoperative treatment was delivered in 12 patients (2 x 7 Gy to the PTV with a 4-7-day interval between fractions). In the 4 nonoperated patients, a dose of 4 Gy/fraction in 5 fractions with 2 to 3 days' interval was delivered. Patients were immobilized in a customized vacuum body cast and optimally repositioned with an infrared-guided system developed for extracranial SRT. To further optimize daily repositioning and target immobilization, an inflated rectal balloon was used during each treatment fraction. In 10 patients, CT resimulation was performed before the last boost fraction to assess for repositioning reproducibility via CT-to-CT registration and to estimate PTV safety margins around the CTV. Finally, a comparative treatment planning study between BT and SRT was performed in 2 patients with an operated endometrial Stage I cancer. Results: No patient developed severe acute urinary or low-intestinal toxicity. No patient developed urinary late effects (>6 months). One patient with a vaginal relapse previously irradiated to the pelvic region presented with Grade 3 rectal bleeding 18 months after retreatment

Suggestion for the prostatic fossa clinical target volume in adjuvant or salvage radiotherapy after a radical prostatectomy

International Nuclear Information System (INIS)

Park, Jun Su; Park, Won; Pyo, Hong Ryull; Park, Byung Kwan; Park, Sung Yoon; Choi, Han Yong; Lee, Hyun Moo; Jeon, Seong Soo; Seo, Seong Il; Jeong, Byong Chang; Jeon, Hwang Gyun

2014-01-01

Background and purpose: To assess the location of recurrent tumors and suggest the optimal target volume in adjuvant or salvage radiotherapy (RT) after a radical prostatectomy (RP). Material and methods: From January 2000 to December 2012, 113 patients had been diagnosed with suspected recurrent prostate cancer by MRI scan and received salvage RT in the Samsung Medical Center. This study assessed the location of the suspected tumor recurrences and used the inferior border of the pubic symphysis as a point of reference. Results: There were 118 suspect tumor recurrences. The most common site of recurrence was the anastomotic site (78.8%), followed by the bladder neck (15.3%) and retrovesical area (5.9%). In the cranial direction, 106 (87.3%) lesions were located within 30 mm of the reference point. In the caudal direction, 12 lesions (10.2%) were located below the reference point. In the transverse plane, 112 lesions (94.9%) were located within 10 mm of the midline. Conclusions: A MRI scan acquired before salvage RT is useful for the localization of recurrent tumors and the delineation of the target volume. We suggest the optimal target volume in adjuvant or salvage RT after RP, which includes 97% of suspected tumor recurrences

Radiotherapy staffing in the European countries: Final results from the ESTRO-HERO survey

International Nuclear Information System (INIS)

Lievens, Yolande; Defourny, Noémie; Coffey, Mary; Borras, Josep M.; Dunscombe, Peter; Slotman, Ben; Malicki, Julian; Bogusz, Marta; Gasparotto, Chiara; Grau, Cai; Kokobobo, Arianit; Sedlmayer, Felix; Slobina, Elena; Coucke, Philippe; Gabrovski, Roumen; Vosmik, Milan; Eriksen, Jesper Grau; Jaal, Jana; Dejean, Catherine; Polgar, Csaba

2014-01-01

Background: The ESTRO Health Economics in Radiation Oncology (HERO) project has the overall aim to develop a knowledge base of the provision of radiotherapy in Europe and build a model for health economic evaluation of radiation treatments at the European level. The first milestone was to assess the availability of radiotherapy resources within Europe. This paper presents the personnel data collected in the ESTRO HERO database. Materials and methods: An 84-item questionnaire was sent out to European countries, through their national scientific and professional radiotherapy societies. The current report includes a detailed analysis of radiotherapy staffing (questionnaire items 47–60), analysed in relation to the annual number of treatment courses and the socio-economic status of the countries. The analysis was conducted between February and July 2014, and is based on validated responses from 24 of the 40 European countries defined by the European Cancer Observatory (ECO). Results: A large variation between countries was found for most parameters studied. Averages and ranges for personnel numbers per million inhabitants are 12.8 (2.5–30.9) for radiation oncologists, 7.6 (0–19.7) for medical physicists, 3.5 (0–12.6) for dosimetrists, 26.6 (1.9–78) for RTTs and 14.8 (0.4–61.0) for radiotherapy nurses. The combined average for physicists and dosimetrists is 9.8 per million inhabitants and 36.9 for RTT and nurses. Radiation oncologists on average treat 208.9 courses per year (range: 99.9–348.8), physicists and dosimetrists conjointly treat 303.3 courses (range: 85–757.7) and RTT and nurses 76.8 (range: 25.7–156.8). In countries with higher GNI per capita, all personnel categories treat fewer courses per annum than in less affluent countries. This relationship is most evident for RTTs and nurses. Different clusters of countries can be distinguished on the basis of available personnel resources and socio-economic status. Conclusions: The average personnel

Radiotherapy staffing in the European countries: final results from the ESTRO-HERO survey.

Science.gov (United States)

Lievens, Yolande; Defourny, Noémie; Coffey, Mary; Borras, Josep M; Dunscombe, Peter; Slotman, Ben; Malicki, Julian; Bogusz, Marta; Gasparotto, Chiara; Grau, Cai; Kokobobo, Arianit; Sedlmayer, Felix; Slobina, Elena; Coucke, Philippe; Gabrovski, Roumen; Vosmik, Milan; Eriksen, Jesper Grau; Jaal, Jana; Dejean, Catherine; Polgar, Csaba; Johannsson, Jakob; Cunningham, Moya; Atkocius, Vydmantas; Back, Carlo; Pirotta, Martin; Karadjinovic, Vanja; Levernes, Sverre; Maciejewski, Boguslaw; Trigo, Maria Lurdes; Šegedin, Barbara; Palacios, Amalia; Pastoors, Bert; Beardmore, Charlotte; Erridge, Sara; Smyth, Gaile; Cleries Soler, Ramon

2014-08-01

The ESTRO Health Economics in Radiation Oncology (HERO) project has the overall aim to develop a knowledge base of the provision of radiotherapy in Europe and build a model for health economic evaluation of radiation treatments at the European level. The first milestone was to assess the availability of radiotherapy resources within Europe. This paper presents the personnel data collected in the ESTRO HERO database. An 84-item questionnaire was sent out to European countries, through their national scientific and professional radiotherapy societies. The current report includes a detailed analysis of radiotherapy staffing (questionnaire items 47-60), analysed in relation to the annual number of treatment courses and the socio-economic status of the countries. The analysis was conducted between February and July 2014, and is based on validated responses from 24 of the 40 European countries defined by the European Cancer Observatory (ECO). A large variation between countries was found for most parameters studied. Averages and ranges for personnel numbers per million inhabitants are 12.8 (2.5-30.9) for radiation oncologists, 7.6 (0-19.7) for medical physicists, 3.5 (0-12.6) for dosimetrists, 26.6 (1.9-78) for RTTs and 14.8 (0.4-61.0) for radiotherapy nurses. The combined average for physicists and dosimetrists is 9.8 per million inhabitants and 36.9 for RTT and nurses. Radiation oncologists on average treat 208.9 courses per year (range: 99.9-348.8), physicists and dosimetrists conjointly treat 303.3 courses (range: 85-757.7) and RTT and nurses 76.8 (range: 25.7-156.8). In countries with higher GNI per capita, all personnel categories treat fewer courses per annum than in less affluent countries. This relationship is most evident for RTTs and nurses. Different clusters of countries can be distinguished on the basis of available personnel resources and socio-economic status. The average personnel figures in Europe are now consistent with, or even more favourable than

Motion compensation for MRI-guided radiotherapy

NARCIS (Netherlands)

Glitzner, M.

2017-01-01

Radiotherapy aims to deliver a lethal radiation dose to cancer cells immersed in the body using a high energetic photon beam. Due to physiologic motion of the human anatomy (e.g. caused by filling of internal organs or breathing), the target volume is under permanent motion during irradiation,

Targeted intraoperative radiotherapy tumour bed boost during breast-conserving surgery after neoadjuvant chemotherapy

Energy Technology Data Exchange (ETDEWEB)

Kolberg, Hans-Christian; Akpolat-Basci, Leyla; Stephanou, Miltiades [Marienhospital Bottrop gGmbH, Department of Gynecology and Obstetrics, Bottrop (Germany); Loevey, Gyoergy [BORAD, Bottrop (Germany); Fasching, Peter A. [University of Erlangen, Erlangen (Germany); Untch, Michael [Helios Klinikum Berlin-Buch, Berlin (Germany); Liedtke, Cornelia [University Hospital Schleswig-Holstein/Campus Luebeck, Luebeck (Germany); Bulsara, Max [University of Notre Dame, Fremantle (Australia); University College, London (United Kingdom); Vaidya, Jayant S. [University College, London (United Kingdom)

2017-01-15

The use of targeted intraoperative radiotherapy (TARGIT-IORT) as a tumour bed boost during breast-conserving surgery (BCS) for breast cancer has been reported since 1998. We present its use in patients undergoing breast conservation following neoadjuvant therapy (NACT). In this retrospective study involving 116 patients after NACT we compared outcomes of 61 patients who received a tumour bed boost with IORT during lumpectomy versus 55 patients treated in the previous 13 months with external (EBRT) boost. All patients received whole breast radiotherapy. Local recurrence-free survival (LRFS), disease-free survival (DFS), distant disease-free survival (DDFS), breast cancer mortality (BCM), non-breast cancer mortality (NBCM) and overall mortality (OS) were compared. Median follow up was 49 months. The differences in LRFS, DFS and BCM were not statistically significant. The 5-year Kaplan-Meier estimate of OS was significantly better by 15% with IORT: IORT 2 events (96.7%, 95%CI 87.5-99.2), EBRT 9 events (81.7%, 95%CI 67.6-90.1), hazard ratio (HR) 0.19 (0.04-0.87), log rank p = 0.016, mainly due to a reduction of 10.1% in NBCM: IORT 100%, EBRT 89.9% (77.3-95.7), HR (not calculable), log rank p = 0.015. The DDFS was as follows: IORT 3 events (95.1%, 85.5-98.4), EBRT 12 events (69.0%, 49.1-82.4), HR 0.23 (0.06-0.80), log rank p = 0.012. IORT during lumpectomy after neoadjuvant chemotherapy as a tumour bed boost appears to give results that are not worse than external beam radiotherapy boost. These data give further support to the inclusion of such patients in the TARGIT-B (boost) randomised trial that is testing whether IORT boost is superior to EBRT boost. (orig.) [German] Die intraoperative Radiotherapie (TARGIT-IORT) als vorgezogener Boost im Rahmen der brusterhaltenden Therapie (BET) ist seit 1998 Gegenstand der wissenschaftlichen Diskussion. Wir praesentieren Daten zum Einsatz der IORT bei der BET nach neoadjuvanter Therapie (NACT). In diese retrospektive Analyse

Interest of radiotherapy of rectal cancer with synchronous metastases

International Nuclear Information System (INIS)

Tournat, H.; Vendrely, V.; Smith, D.; Capdepont, M.; Maire, J.P.; Cherciu, B.; Laurent, C.; Kantor, G.

2008-01-01

Purpose: There is no consensus about the treatment of rectal tumour when there are synchronous metastases. The interest of radiotherapy is debated. Patients and methods: Thirty-seven patients with rectal tumour and synchronous metastases were treated with radiotherapy first between September 1994 and December 2004. We analysed the tolerance, local control, resectability, overall survival of such a therapeutic strategy. Results: The mean follow-up was 30 months. Twenty-four tumors were resectable for both the primary site and the metastases. Thirteen were unresectable at the time of diagnosis. Thirty-three patients were treated with radio chemotherapy, ten with radiotherapy alone. Eighty-six decimal five percent of them had no pelvic symptom six weeks after the treatment. Twenty-one rectal tumours were finally resected. The disease progressed in six cases during the radiotherapy. Surgery of the metastases was possible for 12 patients with tumour initially resectable. Conclusion: Radio chemotherapy is a 'tolerable' treatment, in spite of more frequent urinary or digestive side-effects. But, if there is no surgery, palliative effect of radiotherapy is limited. (authors)

Improving external beam radiotherapy by combination with internal irradiation.

Science.gov (United States)

Dietrich, A; Koi, L; Zöphel, K; Sihver, W; Kotzerke, J; Baumann, M; Krause, M

2015-07-01

The efficacy of external beam radiotherapy (EBRT) is dose dependent, but the dose that can be applied to solid tumour lesions is limited by the sensitivity of the surrounding tissue. The combination of EBRT with systemically applied radioimmunotherapy (RIT) is a promising approach to increase efficacy of radiotherapy. Toxicities of both treatment modalities of this combination of internal and external radiotherapy (CIERT) are not additive, as different organs at risk are in target. However, advantages of both single treatments are combined, for example, precise high dose delivery to the bulk tumour via standard EBRT, which can be increased by addition of RIT, and potential targeting of micrometastases by RIT. Eventually, theragnostic radionuclide pairs can be used to predict uptake of the radiotherapeutic drug prior to and during therapy and find individual patients who may benefit from this treatment. This review aims to highlight the outcome of pre-clinical studies on CIERT and resultant questions for translation into the clinic. Few clinical data are available until now and reasons as well as challenges for clinical implementation are discussed.

3D Conformal radiotherapy for gastric cancer-results of a comparative planning study

International Nuclear Information System (INIS)

Leong, Trevor; Willis, David; Joon, Daryl Lim; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.

2005-01-01

Background and purpose: Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Materials and methods: Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. Results: The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. Conclusions: 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity

Target volume delineation for head and neck cancer intensity-modulated radiotherapy; Delineation des volumes cibles des cancers des voies aerodigestives superieures en radiotherapie conformationnelle avec modulation d'intensite

Energy Technology Data Exchange (ETDEWEB)

Lapeyre, M.; Toledano, I.; Bourry, N. [Departement de radiotherapie, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France); Bailly, C. [Unite de radiodiagnostic, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France); Cachin, F. [Unite de medecine nucleaire, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France)

2011-10-15

This article describes the determination and the delineation of the target volumes for head-and-neck cancers treated with intensity-modulated radiotherapy (IMRT). The delineation of the clinical target volumes (CTV) on the computerized tomography scanner (CT scan) requires a rigorous methodology due to the complexity of head-and-neck anatomy. The clinical examination with a sketch of pretreatment tumour extension, the surgical and pathological reports and the adequate images (CT scan, magnetic resonance imaging and fluorodeoxyglucose positron emission tomography) are necessary for the delineation. The target volumes depend on the overall strategy: sequential IMRT or simultaneous integrated boost-IMRT (SIB-IMRT). The concept of selectivity of the potential subclinical disease near the primary tumor and the selection of neck nodal targets are described according to the recommendations and the literature. The planing target volume (PTV), mainly reflecting setup errors (random and systematic), results from a uniform 4-5 mm expansion around the CTV. We propose the successive delineation of: (1) the gross volume tumour (GTV); (2) the 'high risk' CTV1 around the GTV or including the postoperative tumour bed in case of positive margins or nodal extra-capsular spread (65-70 Gy in 30-35 fractions); (3) the CTV2 'intermediate risk' around the CTV1 for SIB-IMRT (59-63 Gy in 30-35 fractions); (4) the 'low-risk' CTV3 (54-56 Gy in 30-35 fractions); (5) the PTVs. (authors)

Feasibility of tomotherapy for Graves' ophthalmopathy. Dosimetry comparison with conventional radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Nam P.; Krafft, Shane P. [Arizona Univ., Tucson, AZ (United States). Dept. of Radiation Oncology; Vos, Paul [East Carolina Univ., Greenville, NC (US). Dept. of Biostatistics] (and others)

2011-09-15

To compare the dosimetry of tomotherapy and the conventional half-beam technique (HBT) or non-split beam technique (NSBT) for target coverage and radiation dose to the lacrimal glands and lens. A retrospective review of 7 patients with Graves' ophthalmopathy who had radiotherapy because of disease progression on high steroid dose is reported: 3 patients were treated with tomotherapy and 4 patients with HBT. Compared to HBT, tomotherapy may provide better target coverage and significant reduction of radiation dose to the lacrimal glands and a higher dose to the lens. The NSBT improved target coverage but resulted in significantly higher doses to the lens and lacrimal glands. Tomotherapy may provide better coverage of the target volume and may be more effective in reducing severe exophthalmos compared to the conventional radiotherapy technique. (orig.)

Radiotherapy

Directory of Open Access Journals (Sweden)

Rema Jyothirmayi

1999-01-01

Full Text Available Purpose. Conservative treatment in the form of limited surgery and post-operative radiotherapy is controversial in hand and foot sarcomas, both due to poor radiation tolerance of the palm and sole, and due to technical difficulties in achieving adequate margins.This paper describes the local control and survival of 41 patients with soft tissue sarcoma of the hand or foot treated with conservative surgery and radiotherapy. The acute and late toxicity of megavoltage radiotherapy to the hand and foot are described. The technical issues and details of treatment delivery are discussed. The factors influencing local control after radiotherapy are analysed.

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

Energy Technology Data Exchange (ETDEWEB)

Monterroso, M; Dogan, N; Yang, Y [University Miami, Miami, FL (United States)

2014-06-01

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

Conformal radiotherapy by intensity modulation of pediatrics tumors; Radiotherapie conformationnelle par modulation d'intensite des tumeurs pediatriques

Energy Technology Data Exchange (ETDEWEB)

Leseur, J.; Le Prise, E. [Centre Eugene-Marquis, 35 - Rennes (France); Carrie, C. [Centre Leon Berard, 69 - Lyon (France); Bernier, V. [Centre Alexis-Vautrin, 54 - Nancy (France); Beneyton, V. [Centre Paul-Strauss, 67 - Strasbourg (France); Mahe, M.A.; Supiot, S. [Centre Rene-Gauducheau, 44 - Nantes (France)

2009-10-15

The objective of this study is to take stock on the validated and potential indications of the conformal radiotherapy with intensity modulation ( intensity modulated radiotherapy I.M.R.T.) in pediatrics and to propose recommendations for its use as well as the adapted dose constraints. About 40 to 50% of children treated for a cancer are irradiated. The I.M.R.T., by linear accelerator or helical tomo-therapy has for aim to give a homogenous dose to the target volume and to save organs at risk. Its use in pediatrics seems particularly interesting because of the complexity of target volumes and the closeness of organs at risk. In compensation for these positive elements, the importance of low doses irradiation given in big volumes makes fear event consequences on growth and an increased incidence of secondary cancers in children suffering from tumors with high cure rates and long life expectancy. (N.C.)

Processing and evaluation of image matching tools in radiotherapy; Mise en oeuvre et evaluation d'outils de fusion d'image en radiotherapie

Energy Technology Data Exchange (ETDEWEB)

Bondiau, P Y

2004-11-15

Cancer is a major problem of public health. Treatment can be done in a general or loco-regional way, in this last case medical images are important as they specify the localization of the tumour. The objective of the radiotherapy is to deliver a curative dose of radiation in the target volume while sparing the organs at risks (O.A.R.). The determination of the accurate localization of the targets volume as well as O.A.R. make it possible to define the ballistic of irradiation beams. After the description of the principles of radiotherapy and cancers treatment, we specify the clinical stakes of ocular, cerebral and prostatic tumours. We present a state of the art of image matching, the various techniques reviewed with an aim of being didactic with respect to the medical community. The results of matching are presented within the framework of the planning of the cerebral and prostatic radiotherapy in order to specify the types of applicable matching in oncology and more particularly in radiotherapy. Then, we present the prospects for this type of application according to various anatomical areas. Applications of automatic segmentation and the evaluation of the results in the framework of brain tumour are described after a review of the various segmentation methods according to anatomical localizations. We will see an original application: the digital simulation of the virtual tumoral growth and the comparison with the real growth of a cerebral tumour presented by a patient. Lastly, we will expose the future developments possible of the tools for image processing in radiotherapy as well as the tracks of research to be explored in oncology. (author)

Variations in Target Volume Definition for Postoperative Radiotherapy in Stage III Non-Small-Cell Lung Cancer: Analysis of an International Contouring Study

International Nuclear Information System (INIS)

Spoelstra, Femke; Senan, Suresh; Le Pechoux, Cecile; Ishikura, Satoshi; Casas, Francesc; Ball, David; Price, Allan; De Ruysscher, Dirk; Soernsen de Koste, John R. van

2010-01-01

Purpose: Postoperative radiotherapy (PORT) in patients with completely resected non-small-cell lung cancer with mediastinal involvement is controversial because of the failure of earlier trials to demonstrate a survival benefit. Improved techniques may reduce toxicity, but the treatment fields used in routine practice have not been well studied. We studied routine target volumes used by international experts and evaluated the impact of a contouring protocol developed for a new prospective study, the Lung Adjuvant Radiotherapy Trial (Lung ART). Methods and Materials: Seventeen thoracic radiation oncologists were invited to contour their routine clinical target volumes (CTV) for 2 representative patients using a validated CD-ROM-based contouring program. Subsequently, the Lung ART study protocol was provided, and both cases were contoured again. Variations in target volumes and their dosimetric impact were analyzed. Results: Routine CTVs were received for each case from 10 clinicians, whereas six provided both routine and protocol CTVs for each case. Routine CTVs varied up to threefold between clinicians, but use of the Lung ART protocol significantly decreased variations. Routine CTVs in a postlobectomy patient resulted in V 20 values ranging from 12.7% to 54.0%, and Lung ART protocol CTVs resulted in values of 20.6% to 29.2%. Similar results were seen for other toxicity parameters and in the postpneumectomy patient. With the exception of upper paratracheal nodes, protocol contouring improved coverage of the required nodal stations. Conclusion: Even among experts, significant interclinician variations are observed in PORT fields. Inasmuch as contouring variations can confound the interpretation of PORT results, mandatory quality assurance procedures have been incorporated into the current Lung ART study.

Hippocampal-Sparing Whole-Brain Radiotherapy: A 'How-To' Technique Using Helical Tomotherapy and Linear Accelerator-Based Intensity-Modulated Radiotherapy

International Nuclear Information System (INIS)

Gondi, Vinai; Tolakanahalli, Ranjini; Mehta, Minesh P.; Tewatia, Dinesh; Rowley, Howard; Kuo, John S.; Khuntia, Deepak; Tome, Wolfgang A.

2010-01-01

Purpose: Sparing the hippocampus during cranial irradiation poses important technical challenges with respect to contouring and treatment planning. Herein we report our preliminary experience with whole-brain radiotherapy using hippocampal sparing for patients with brain metastases. Methods and Materials: Five anonymous patients previously treated with whole-brain radiotherapy with hippocampal sparing were reviewed. The hippocampus was contoured, and hippocampal avoidance regions were created using a 5-mm volumetric expansion around the hippocampus. Helical tomotherapy and linear accelerator (LINAC)-based intensity-modulated radiotherapy (IMRT) treatment plans were generated for a prescription dose of 30 Gy in 10 fractions. Results: On average, the hippocampal avoidance volume was 3.3 cm 3 , occupying 2.1% of the whole-brain planned target volume. Helical tomotherapy spared the hippocampus, with a median dose of 5.5 Gy and maximum dose of 12.8 Gy. LINAC-based IMRT spared the hippocampus, with a median dose of 7.8 Gy and maximum dose of 15.3 Gy. On a per-fraction basis, mean dose to the hippocampus (normalized to 2-Gy fractions) was reduced by 87% to 0.49 Gy 2 using helical tomotherapy and by 81% to 0.73 Gy 2 using LINAC-based IMRT. Target coverage and homogeneity was acceptable with both IMRT modalities, with differences largely attributed to more rapid dose fall-off with helical tomotherapy. Conclusion: Modern IMRT techniques allow for sparing of the hippocampus with acceptable target coverage and homogeneity. Based on compelling preclinical evidence, a Phase II cooperative group trial has been developed to test the postulated neurocognitive benefit.

Health economics of targeted intraoperative radiotherapy (TARGIT-IORT) for early breast cancer: a cost-effectiveness analysis in the United Kingdom.

Science.gov (United States)

Vaidya, Anil; Vaidya, Param; Both, Brigitte; Brew-Graves, Chris; Bulsara, Max; Vaidya, Jayant S

2017-08-17

The clinical effectiveness of targeted intraoperative radiotherapy (TARGIT-IORT) has been confirmed in the randomised TARGIT-A (targeted intraoperative radiotherapy-alone) trial to be similar to a several weeks' course of whole-breast external-beam radiation therapy (EBRT) in patients with early breast cancer. This study aims to determine the cost-effectiveness of TARGIT-IORT to inform policy decisions about its wider implementation. TARGIT-A randomised clinical trial (ISRCTN34086741) which compared TARGIT with traditional EBRT and found similar breast cancer control, particularly when TARGIT was given simultaneously with lumpectomy. Cost-utility analysis using decision analytic modelling by a Markov model. A cost-effectiveness Markov model was developed using TreeAge Pro V.2015. The decision analytic model compared two strategies of radiotherapy for breast cancer in a hypothetical cohort of patients with early breast cancer based on the published health state transition probability data from the TARGIT-A trial. Analysis was performed for UK setting and National Health Service (NHS) healthcare payer's perspective using NHS cost data and treatment outcomes were simulated for both strategies for a time horizon of 10 years. Model health state utilities were drawn from the published literature. Future costs and effects were discounted at the rate of 3.5%. To address uncertainty, one-way and probabilistic sensitivity analyses were performed. Quality-adjusted life-years (QALYs). In the base case analysis, TARGIT-IORT was a highly cost-effective strategy yielding health gain at a lower cost than its comparator EBRT. Discounted TARGIT-IORT and EBRT costs for the time horizon of 10 years were £12 455 and £13 280, respectively. TARGIT-IORT gained 0.18 incremental QALY as the discounted QALYs gained by TARGIT-IORT were 8.15 and by EBRT were 7.97 showing TARGIT-IORT as a dominant strategy over EBRT. Model outputs were robust to one-way and probabilistic sensitivity analyses

Targeted Intraoperative Radiotherapy for Breast Cancer in Patients in Whom External Beam Radiation Is Not Possible

International Nuclear Information System (INIS)

Keshtgar, Mohammed R.S.; Vaidya, Jayant S.; Tobias, Jeffrey S.; Wenz, Frederik; Joseph, David; Stacey, Chris; Metaxas, Marinos G.; Keller, Anke; Corica, Tammy; Williams, Norman R.; Baum, Michael

2011-01-01

Purpose: External beam radiation therapy (EBRT) following wide local excision of the primary tumor is the standard treatment in early breast cancer. In some circumstances this procedure is not possible or is contraindicated or difficult. The purpose of this study was to determine the safety and efficacy of targeted intraoperative radiotherapy (TARGIT) when EBRT is not feasible. Methods and Materials: We report our experience with TARGIT in three centers (Australia, Germany, and the United Kingdom) between 1999 and 2008. Patients at these centers received a single radiation dose of 20 Gy to the breast tissue in contact with the applicator (or 6 Gy at 1-cm distance), as they could not be given EBRT and were keen to avoid mastectomy. Results: Eighty patients were treated with TARGIT. Reasons for using TARGIT were 21 patients had previously received EBRT, and 31 patients had clinical reasons such as systemic lupus erythematosus, motor neuron disease, Parkinson's disease, ankylosing spondylitis, morbid obesity, and cardiovascular or severe respiratory disease. Three of these patients received percutaneous radiotherapy without surgery; 28 patients were included for compelling personal reasons, usually on compassionate grounds. After a median follow-up of 38 months, only two local recurrences were observed, an annual local recurrence rate of 0.75% (95% confidence interval, 0.09%-2.70%). Conclusions: While we await the results of the randomized trial (over 2,000 patients have already been recruited), TARGIT is an acceptable option but only in highly selected cases that cannot be recruited in the trial and in whom EBRT is not feasible/possible.

How to use PET/CT in the evaluation of response to radiotherapy.

Science.gov (United States)

Decazes, Pierre; Thureau, Sébastien; Dubray, Bernard; Vera, Pierre

2017-11-28

Radiotherapy is a major treatment modality for many cancers. Tumor response after radiotherapy determines the subsequent steps of the patient's management (surveillance, adjuvant or salvage treatment and palliative care). Tumor response assessed during radiotherapy offers a promising opportunity to adapt the treatment plan to reduced / increased target volume, to specifically target sub-volumes with relevant biological characteristics (metabolism, hypoxia, proliferation ...) and to further spare the organs at risk. In addition to its role in the diagnosis and the initial staging, Positron Emission Tomography combined with a Computed Tomography (PET/CT) provides functional information and is therefore attractive to evaluate tumor response. To review the published data addressing PET/CT as an evaluation tool in irradiated tumors. Reports on PET/CT acquired at various times (during radiotherapy, after initial (chemo-)radiotherapy, after definitive radiotherapy and during posttreatment follow-up) in solid tumors (lung, head-and-neck, cervix, esophagus, prostate and rectum) were collected and reviewed. Various tracers and technical are also discussed. 18F-FDG PET/CT has a well-established role in clinical routine after definitive chemo-radiotherapy for locally advanced head-and-neck cancers. 18F-choline PET/CT is indicated in prostate cancer patients with biochemical failure. 18F-FDG PET/CT is optional in many others circumstances and the clinical benefits of assessing tumor response with PET/CT remain a field of very active research. The combination of PET with Magnetic Resonance Imaging (PET/MRI) may prove to be valuable in irradiated rectal and cervix cancers. Tumor response can be evaluated by PET/CT with clinical consequences in multiple situations, notably in head and neck and prostate cancers, after radiotherapy. Further clinical evaluation for most cancers is still needed, possibly in association to MRI.

Can FDG-PET assist in radiotherapy target volume definition of metastatic lymph nodes in head-and-neck cancer?

International Nuclear Information System (INIS)

Schinagl, Dominic A.X.; Hoffmann, Aswin L.; Vogel, Wouter V.; Dalen, Jorn A. van; Verstappen, Suzan M.M.; Oyen, Wim J.G.; Kaanders, Johannes H.A.M.

2009-01-01

Background and purpose: The role of FDG-PET in radiotherapy target volume definition of the neck was evaluated by comparing eight methods of FDG-PET segmentation to the current CT-based practice of lymph node assessment in head-and-neck cancer patients. Materials and methods: Seventy-eight head-and-neck cancer patients underwent coregistered CT- and FDG-PET scans. Lymph nodes were classified as 'enlarged' if the shortest axial diameter on CT was ≥10 mm, and as 'marginally enlarged' if it was 7-10 mm. Subsequently, lymph nodes were assessed on FDG-PET applying eight segmentation methods: visual interpretation (PET VIS ), applying fixed thresholds at a standardized uptake value (SUV) of 2.5 and at 40% and 50% of the maximum signal intensity of the primary tumor (PET SUV , PET 40% , PET 50% ) and applying a variable threshold based on the signal-to-background ratio (PET SBR ). Finally, PET 40%N , PET 50%N and PET SBRN were acquired using the signal of the lymph node as the threshold reference. Results: Of 108 nodes classified as 'enlarged' on CT, 75% were also identified by PET VIS , 59% by PET 40% , 43% by PET 50% and 43% by PET SBR . Of 100 nodes classified as 'marginally enlarged', only a minority were visualized by FDG-PET. The respective numbers were 26%, 10%, 7% and 8% for PET VIS , PET 40% , PET 50% and PET SBR . PET 40%N , PET 50%N and PET SBRN , respectively, identified 66%, 82% and 96% of the PET VIS -positive nodes. Conclusions: Many lymph nodes that are enlarged and considered metastatic by standard CT-based criteria appear to be negative on FDG-PET scan. Alternately, a small proportion of marginally enlarged nodes are positive on FDG-PET scan. However, the results are largely dependent on the PET segmentation tool used, and until proper validation FDG-PET is not recommended for target volume definition of metastatic lymph nodes in routine practice.

SU-E-J-159: Analysis of Total Imaging Uncertainty in Respiratory-Gated Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Suzuki, J; Okuda, T [Toyota memorial hospital, Toyota, Aichi (Japan); Sakaino, S; Yokota, N [Suzukake central hospital, Hamamatsu, Shizuoka (Japan)

2015-06-15

Purpose: In respiratory-gated radiotherapy, the gating phase during treatment delivery needs to coincide with the corresponding phase determined during the treatment plan. However, because radiotherapy is performed based on the image obtained for the treatment plan, the time delay, motion artifact, volume effect, and resolution in the images are uncertain. Thus, imaging uncertainty is the most basic factor that affects the localization accuracy. Therefore, these uncertainties should be analyzed. This study aims to analyze the total imaging uncertainty in respiratory-gated radiotherapy. Methods: Two factors of imaging uncertainties related to respiratory-gated radiotherapy were analyzed. First, CT image was used to determine the target volume and 4D treatment planning for the Varian Realtime Position Management (RPM) system. Second, an X-ray image was acquired for image-guided radiotherapy (IGRT) for the BrainLAB ExacTrac system. These factors were measured using a respiratory gating phantom. The conditions applied during phantom operation were as follows: respiratory wave form, sine curve; respiratory cycle, 4 s; phantom target motion amplitude, 10, 20, and 29 mm (which is maximum phantom longitudinal motion). The target and cylindrical marker implanted in the phantom coverage of the CT images was measured and compared with the theoretically calculated coverage from the phantom motion. The theoretical position of the cylindrical marker implanted in the phantom was compared with that acquired from the X-ray image. The total imaging uncertainty was analyzed from these two factors. Results: In the CT image, the uncertainty between the target and cylindrical marker’s actual coverage and the coverage of CT images was 1.19 mm and 2.50mm, respectively. In the Xray image, the uncertainty was 0.39 mm. The total imaging uncertainty from the two factors was 1.62mm. Conclusion: The total imaging uncertainty in respiratory-gated radiotherapy was clinically acceptable. However

SU-E-J-159: Analysis of Total Imaging Uncertainty in Respiratory-Gated Radiotherapy

International Nuclear Information System (INIS)

Suzuki, J; Okuda, T; Sakaino, S; Yokota, N

2015-01-01

Purpose: In respiratory-gated radiotherapy, the gating phase during treatment delivery needs to coincide with the corresponding phase determined during the treatment plan. However, because radiotherapy is performed based on the image obtained for the treatment plan, the time delay, motion artifact, volume effect, and resolution in the images are uncertain. Thus, imaging uncertainty is the most basic factor that affects the localization accuracy. Therefore, these uncertainties should be analyzed. This study aims to analyze the total imaging uncertainty in respiratory-gated radiotherapy. Methods: Two factors of imaging uncertainties related to respiratory-gated radiotherapy were analyzed. First, CT image was used to determine the target volume and 4D treatment planning for the Varian Realtime Position Management (RPM) system. Second, an X-ray image was acquired for image-guided radiotherapy (IGRT) for the BrainLAB ExacTrac system. These factors were measured using a respiratory gating phantom. The conditions applied during phantom operation were as follows: respiratory wave form, sine curve; respiratory cycle, 4 s; phantom target motion amplitude, 10, 20, and 29 mm (which is maximum phantom longitudinal motion). The target and cylindrical marker implanted in the phantom coverage of the CT images was measured and compared with the theoretically calculated coverage from the phantom motion. The theoretical position of the cylindrical marker implanted in the phantom was compared with that acquired from the X-ray image. The total imaging uncertainty was analyzed from these two factors. Results: In the CT image, the uncertainty between the target and cylindrical marker’s actual coverage and the coverage of CT images was 1.19 mm and 2.50mm, respectively. In the Xray image, the uncertainty was 0.39 mm. The total imaging uncertainty from the two factors was 1.62mm. Conclusion: The total imaging uncertainty in respiratory-gated radiotherapy was clinically acceptable. However

Challenges in successfully developing three regional radiotherapy centres. The NCCI experience

International Nuclear Information System (INIS)

Greenham, Stuart

2011-01-01

Full text: This presentation will provide an overview of the processes, experience, challenges and success involved in the establishment of the North Coast Cancer Institute (NCCI). The NCCI is a network of three Integrated Oncology centres in Northern New South Wales offering integrated Medical, Radiation and Haematology outpatient services. NCCI was developed as part of the introduction of radiotherapy into a region previously without access to a local radiotherapy service and as a result with poor radiotherapy utilisation and referral rates. NCCI commenced radiotherapy services in Coffs Harbour in May 2007 followed by Port Macquarie in August of the same year and finally in Lismore in May 20 I O. Radiotherapy services commenced with Intensity Modulated Radiotherapy and Image guided radiotherapy as standard of care for some disease sites with remote access to planning systems and electronic workflow process supporting the treatment process. Forming a small team to simultaneously design, build and establish two new treatment centres to take advantage of the most contemporary treatment modalities while also planning for a third centre was a significant challenge. The challenges and successful outcomes will be discussed as part of this presentation.

Lung cancer: Value of computed tomography in radiotherapy planning and evaluation of tumour remission

International Nuclear Information System (INIS)

Feyerabend, T.; Schmitt, R.; Richter, E.; Bohndorf, W.

1990-01-01

434 CT examinations of 133 patients with histologically proven bronchogenic carcinoma (22 out of 133 with small cell lung cancer) were analysed before and after radiotherapy. The study evaluates the use of CT for determining target volume, tumour volume and remission rate: 1. Concerning determination of target volume conventional roentgendiagnostic simulator methods are much inferior to CT aided planning; as for our patients changes of the target volume were necessary in 50%, in 22% the changes were crucial. This happened more often in non-small cell lung cancer than in small cell carcinomas. 2. The response rate (CR + PR) after radiotherapy (based on the calculated tumour volumes by CT) was 70 to 80%. The rate of CR of the primary was 45% (non-small cell carcinoma) and 67% (small cell carcinoma). 3. The crucial point for the evaluation of tumour remission after radiotherapy is the point of time. One to three months and four to nine months after irradiation we found complete remissions in 19% and 62%, respectively. Hence, the evaluation of treatment results earlier than three months after radiotherapy may be incorrect. We deem it indispensable to use CT for determination of target, calculation of dose distribution and accurate evaluation of tumour remission and side effects during and after irradiation of patients with bronchogenic carcinoma. (orig.) [de

Radiotherapy in Cancer Management

International Nuclear Information System (INIS)

Abdel-Wahab, M.

2015-01-01

Radiotherapy has been used for curative or palliative treatment of cancer, either alone or increasingly as part of a multimodality approach in conjunction with chemotherapy, immunotherapy or surgery. Radiation must be delivered in the safest and most effective way. The use of radiologic and nuclear medicine diagnostic techniques, e.g., the use of CT (Computerized Tomography) and PET/CT allow better detection and staging of diseases by displaying both morphological and functional abnormalities within the affected organs and are essential in the process of radiotherapy planning. Technical advances in radiotherapy have allowed better targeting of tumors, sparing of normal tissue and, in the case of radiosurgery, a decrease in the number of treatments. The IAEA Programme in Human Health aims to enhance the capabilities in Member States to address needs related to the treatment of diseases, including cancer, through the application of nuclear techniques. The Programme supports quality assurance in radiation medicine; DIRAC, the only radiation oncology-specific resource database world-wide; significant, innovative education and training programmes through telemedicine and e-learning accessible via the human health campus website. Technical expertise for country– and region–specific technical cooperation radiation-medicine projects is provided to establish or enhance radiation medicine worldwide. (author)

Cancer-associated stroma affects FDG uptake in experimental carcinomas. Implications for FDG-PET delineation of radiotherapy target

Energy Technology Data Exchange (ETDEWEB)

Farace, Paolo; Merigo, Flavia; Galie, Mirco; Sbarbati, Andrea; Marzola, Pasquina [University of Verona, Department of Morphological-Biomedical Sciences, Section of Anatomy and Histology, Verona (Italy); D' Ambrosio, Daniela; Nanni, Cristina; Spinelli, Antonello; Fanti, Stefano [Policlinico ' S. Orsola-Malpighi' , Department of Nuclear Medicine, Bologna (Italy); Degrassi, Anna [Nerviano Medical Sciences, Milan (Italy); Rubello, Domenico [' S. Maria della Misericordia' Hospital, PET Centre, Department of Nuclear Medicine, Rovigo (Italy)

2009-04-15

To analyse the influence of cancer-associated stroma on FDG-uptake in two carcinoma models characterized by different stromal degrees. Eight nude mice were subcutaneously injected with DU-145 prostate cancer cells or BXPC-3 pancreatic cancer cells, and underwent FDG-PET imaging about 2 weeks after implantation. After the mice were killed, histology, and CD31 and GLUT1 immunohistochemistry were performed. To further evaluate the highly stromalized carcinoma using perfusion-sensitive imaging, four BXPC-3 tumours underwent two successive albumin-binding (MS-325) MRI scans during tumour growth. FDG uptake was significantly higher in the DU-145 than in the BXPC-3 tumours, which were hardly distinguishable from adjacent normal tissue. In the BXPC-3 tumours, histology confirmed the widespread presence of aberrant infiltrated stroma, embedded with numerous vessels marked by CD31. In both tumour types, the stromal matrix was negative for GLUT1. In DU-145 tumour cells, GLUT1 immunostaining was greater than in BXPC-3 tumour cells, but not homogeneously, since it was less evident in the tumour cells which were nearer to vessels and stroma. Finally, MS-325 MRI always clearly showed areas of enhancement in the BXPC-3 tumours. Cancer-associated stroma has been reported to be capable of aerobic metabolism with low glucose consumption. Furthermore, it has been proposed that regions with high vascular perfusion exhibit a significantly lower FDG uptake, suggesting some vascular/metabolic reciprocity. Since our results are consistent with these recent findings, they signal a risk of tumour volume underestimation in radiotherapy if FDG uptake alone is used for target delineation of carcinomas, which suggests that additional evaluation should be performed using vasculature/perfusion-sensitive imaging. (orig.)

Cancer-associated stroma affects FDG uptake in experimental carcinomas. Implications for FDG-PET delineation of radiotherapy target.

Science.gov (United States)

Farace, Paolo; D'Ambrosio, Daniela; Merigo, Flavia; Galiè, Mirco; Nanni, Cristina; Spinelli, Antonello; Fanti, Stefano; Degrassi, Anna; Sbarbati, Andrea; Rubello, Domenico; Marzola, Pasquina

2009-04-01

To analyse the influence of cancer-associated stroma on FDG-uptake in two carcinoma models characterized by different stromal degrees. Eight nude mice were subcutaneously injected with DU-145 prostate cancer cells or BXPC-3 pancreatic cancer cells, and underwent FDG-PET imaging about 2 weeks after implantation. After the mice were killed, histology, and CD31 and GLUT1 immunohistochemistry were performed. To further evaluate the highly stromalized carcinoma using perfusion-sensitive imaging, four BXPC-3 tumours underwent two successive albumin-binding (MS-325) MRI scans during tumour growth. FDG uptake was significantly higher in the DU-145 than in the BXPC-3 tumours, which were hardly distinguishable from adjacent normal tissue. In the BXPC-3 tumours, histology confirmed the widespread presence of aberrant infiltrated stroma, embedded with numerous vessels marked by CD31. In both tumour types, the stromal matrix was negative for GLUT1. In DU-145 tumour cells, GLUT1 immunostaining was greater than in BXPC-3 tumour cells, but not homogeneously, since it was less evident in the tumour cells which were nearer to vessels and stroma. Finally, MS-325 MRI always clearly showed areas of enhancement in the BXPC-3 tumours. Cancer-associated stroma has been reported to be capable of aerobic metabolism with low glucose consumption. Furthermore, it has been proposed that regions with high vascular perfusion exhibit a significantly lower FDG uptake, suggesting some vascular/metabolic reciprocity. Since our results are consistent with these recent findings, they signal a risk of tumour volume underestimation in radiotherapy if FDG uptake alone is used for target delineation of carcinomas, which suggests that additional evaluation should be performed using vasculature/perfusion-sensitive imaging.

Cancer-associated stroma affects FDG uptake in experimental carcinomas. Implications for FDG-PET delineation of radiotherapy target

International Nuclear Information System (INIS)

Farace, Paolo; Merigo, Flavia; Galie, Mirco; Sbarbati, Andrea; Marzola, Pasquina; D'Ambrosio, Daniela; Nanni, Cristina; Spinelli, Antonello; Fanti, Stefano; Degrassi, Anna; Rubello, Domenico

2009-01-01

To analyse the influence of cancer-associated stroma on FDG-uptake in two carcinoma models characterized by different stromal degrees. Eight nude mice were subcutaneously injected with DU-145 prostate cancer cells or BXPC-3 pancreatic cancer cells, and underwent FDG-PET imaging about 2 weeks after implantation. After the mice were killed, histology, and CD31 and GLUT1 immunohistochemistry were performed. To further evaluate the highly stromalized carcinoma using perfusion-sensitive imaging, four BXPC-3 tumours underwent two successive albumin-binding (MS-325) MRI scans during tumour growth. FDG uptake was significantly higher in the DU-145 than in the BXPC-3 tumours, which were hardly distinguishable from adjacent normal tissue. In the BXPC-3 tumours, histology confirmed the widespread presence of aberrant infiltrated stroma, embedded with numerous vessels marked by CD31. In both tumour types, the stromal matrix was negative for GLUT1. In DU-145 tumour cells, GLUT1 immunostaining was greater than in BXPC-3 tumour cells, but not homogeneously, since it was less evident in the tumour cells which were nearer to vessels and stroma. Finally, MS-325 MRI always clearly showed areas of enhancement in the BXPC-3 tumours. Cancer-associated stroma has been reported to be capable of aerobic metabolism with low glucose consumption. Furthermore, it has been proposed that regions with high vascular perfusion exhibit a significantly lower FDG uptake, suggesting some vascular/metabolic reciprocity. Since our results are consistent with these recent findings, they signal a risk of tumour volume underestimation in radiotherapy if FDG uptake alone is used for target delineation of carcinomas, which suggests that additional evaluation should be performed using vasculature/perfusion-sensitive imaging. (orig.)

Stereotactic intracranial radiotherapy: Dose prescription

International Nuclear Information System (INIS)

Schlienger, M.; Lartigau, E.; Nataf, F.; Mornex, F.; Latorzeff, I.; Lisbona, A.; Mahe, M.

2012-01-01

The aim of this article was the study of the successive steps permitting the prescription of dose in stereotactic intracranial radiotherapy, which includes radiosurgery and fractionated stereotactic radiotherapy. The successive steps studied are: the choice of stereotactic intracranial radiotherapy among the therapeutic options, based on curative or palliative treatment intent, then the selection of lesions according to size/volume, pathological type and their number permitting the choice between radiosurgery or fractionated stereotactic radiotherapy, which have the same methodological basis. Clinical experience has determined the level of dose to treat the lesions and limit the irradiation of healthy adjacent tissues and organs at risk structures. The last step is the optimization of the different parameters to obtain a safe compromise between the lesion dose and healthy adjacent structures. Study of dose-volume histograms, coverage indices and 3D imaging permit the optimization of irradiation. For lesions close to or included in a critical area, the prescribed dose is planned using the inverse planing method. Implementation of the successively described steps is mandatory to insure the prescription of an optimized dose. The whole procedure is based on the delineation of the lesion and adjacent healthy tissues. There are sometimes difficulties to assess the delineation and the volume of the target, however improvement of local control rates and reduction of secondary effects are the proof that the totality of the successive procedures are progressively improved. In practice, stereotactic intracranial radiotherapy is a continually improved treatment method, which constantly benefits from improvements in the choice of indications, imaging, techniques of irradiation, planing/optimization methodology and irradiation technique and from data collected from prolonged follow-up. (authors)

Postoperative Radiotherapy in Prostate Cancer: The Case of the Missing Target

International Nuclear Information System (INIS)

Croke, Jennifer; Malone, Shawn; Roustan Delatour, Nicolas; Belanger, Eric; Avruch, Leonard; Morash, Christopher; Kayser, Cathleen; Underhill, Kathryn; Spaans, Johanna

2012-01-01

Purpose: Postoperative radiotherapy (XRT) increases survival in high-risk prostate cancer patients. Approximately 50% of patients on long-term follow-up relapse despite adjuvant XRT and the predominant site of failure remains local. Four consensus guidelines define postoperative clinical target volume (CTV) in prostate cancer. We explore the possibility that inadequate CTV coverage is an important cause of local failure. This study evaluates the utility of preoperative magnetic resonance imaging (MRI) in defining prostate bed CTV. Methods and Materials: Twenty prostate cancer patients treated with postoperative XRT who also had preoperative staging MRI were included. The four guidelines were applied and the CTVs were expanded to create planning target volumes (PTVs). Preoperative MRIs were fused with postoperative planning CT scans. MRI-based prostate and gross visible tumors were contoured. Three-dimensional (3D) conformal four- and six-field XRT plans were developed and dose–volume histograms analyzed. Subtraction analysis was conducted to assess the adequacy of prostate/gross tumor coverage. Results: Gross tumor was visible in 18 cases. In all 20 cases, the consensus CTVs did not fully cover the MRI-defined prostate. On average, 35% of the prostate volume and 32% of the gross tumor volume were missed using six-field 3D treatment plans. The entire MRI-defined gross tumor volume was completely covered in only two cases (six-field plans). The expanded PTVs did not cover the entire prostate bed in 50% of cases. Prostate base and mid-zones were the predominant site of inadequate coverage. Conclusions: Current postoperative CTV guidelines do not adequately cover the prostate bed and/or gross tumor based on preoperative MRI imaging. Additionally, expanded PTVs do not fully cover the prostate bed in 50% of cases. Inadequate CTV definition is likely a major contributing factor for the high risk of relapse despite adjuvant XRT. Preoperative imaging may lead to more

Benchmarking of Monte Carlo simulation of bremsstrahlung from thick targets at radiotherapy energies

International Nuclear Information System (INIS)

Faddegon, Bruce A.; Asai, Makoto; Perl, Joseph; Ross, Carl; Sempau, Josep; Tinslay, Jane; Salvat, Francesc

2008-01-01

Several Monte Carlo systems were benchmarked against published measurements of bremsstrahlung yield from thick targets for 10-30 MV beams. The quantity measured was photon fluence at 1 m per unit energy per incident electron (spectra), and total photon fluence, integrated over energy, per incident electron (photon yield). Results were reported at 10-30 MV on the beam axis for Al and Pb targets and at 15 MV at angles out to 90 degree sign for Be, Al, and Pb targets. Beam energy was revised with improved accuracy of 0.5% using an improved energy calibration of the accelerator. Recently released versions of the Monte Carlo systems EGSNRC, GEANT4, and PENELOPE were benchmarked against the published measurements using the revised beam energies. Monte Carlo simulation was capable of calculation of photon yield in the experimental geometry to 5% out to 30 degree sign , 10% at wider angles, and photon spectra to 10% at intermediate photon energies, 15% at lower energies. Accuracy of measured photon yield from 0 to 30 degree sign was 5%, 1 s.d., increasing to 7% for the larger angles. EGSNRC and PENELOPE results were within 2 s.d. of the measured photon yield at all beam energies and angles, GEANT4 within 3 s.d. Photon yield at nonzero angles for angles covering conventional field sizes used in radiotherapy (out to 10 degree sign ), measured with an accuracy of 3%, was calculated within 1 s.d. of measurement for EGSNRC, 2 s.d. for PENELOPE and GEANT4. Calculated spectra closely matched measurement at photon energies over 5 MeV. Photon spectra near 5 MeV were underestimated by as much as 10% by all three codes. The photon spectra below 2-3 MeV for the Be and Al targets and small angles were overestimated by up to 15% when using EGSNRC and PENELOPE, 20% with GEANT4. EGSNRC results with the NIST option for the bremsstrahlung cross section were preferred over the alternative cross section available in EGSNRC and over EGS4. GEANT4 results calculated with the ''low energy

Benchmarking of Monte Carlo simulation of bremsstrahlung from thick targets at radiotherapy energies

Energy Technology Data Exchange (ETDEWEB)

Faddegon, Bruce A.; Asai, Makoto; Perl, Joseph; Ross, Carl; Sempau, Josep; Tinslay, Jane; Salvat, Francesc [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California 94143 (United States); Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); National Research Council Canada, Institute for National Measurement Standards, 1200 Montreal Road, Building M-36, Ottawa, Ontario K1A 0R6 (Canada); Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya and Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Diagonal 647, 08028 Barcelona (Spain); Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Facultat de Fisica (ECM), Universitat de Barcelona, Societat Catalana de Fisica (IEC), Diagonal 647, 08028 Barcelona (Spain)

2008-10-15

Several Monte Carlo systems were benchmarked against published measurements of bremsstrahlung yield from thick targets for 10-30 MV beams. The quantity measured was photon fluence at 1 m per unit energy per incident electron (spectra), and total photon fluence, integrated over energy, per incident electron (photon yield). Results were reported at 10-30 MV on the beam axis for Al and Pb targets and at 15 MV at angles out to 90 degree sign for Be, Al, and Pb targets. Beam energy was revised with improved accuracy of 0.5% using an improved energy calibration of the accelerator. Recently released versions of the Monte Carlo systems EGSNRC, GEANT4, and PENELOPE were benchmarked against the published measurements using the revised beam energies. Monte Carlo simulation was capable of calculation of photon yield in the experimental geometry to 5% out to 30 degree sign , 10% at wider angles, and photon spectra to 10% at intermediate photon energies, 15% at lower energies. Accuracy of measured photon yield from 0 to 30 degree sign was 5%, 1 s.d., increasing to 7% for the larger angles. EGSNRC and PENELOPE results were within 2 s.d. of the measured photon yield at all beam energies and angles, GEANT4 within 3 s.d. Photon yield at nonzero angles for angles covering conventional field sizes used in radiotherapy (out to 10 degree sign ), measured with an accuracy of 3%, was calculated within 1 s.d. of measurement for EGSNRC, 2 s.d. for PENELOPE and GEANT4. Calculated spectra closely matched measurement at photon energies over 5 MeV. Photon spectra near 5 MeV were underestimated by as much as 10% by all three codes. The photon spectra below 2-3 MeV for the Be and Al targets and small angles were overestimated by up to 15% when using EGSNRC and PENELOPE, 20% with GEANT4. EGSNRC results with the NIST option for the bremsstrahlung cross section were preferred over the alternative cross section available in EGSNRC and over EGS4. GEANT4 results calculated with the &apos

Change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy: An early predictor of final treatment response

International Nuclear Information System (INIS)

Kim, Eun Young; Choi, Dongil; Lim, Do Hoon; Lee, Won Jae; Yoo, Byung Chul; Paik, Seung Woon

2009-01-01

Background: The purpose of this study was to evaluate the change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy (RT) as an early predictor of final treatment response. Materials: Fifty patients who underwent local RT for HCCs had both pre-RT and post-RT CT scans including 1-month follow-up CT. We assessed the final treatment response by using the change in maximal tumor size on 6-12-month follow-up CT scan after RT. We also evaluated the change in tumor enhancement between pre-RT and 1-month follow-up CT scans. Results: A final treatment response was achieved in 27 (54%) of 50 patients, who showed either a complete response (n = 11) or a partial response (n = 16). Compared with non-responsive patients (n = 23), responsive patients showed a significant decrease in tumor enhancement on 1-month follow-up CT after RT in both objective and subjective analyses (each P < 0.001). Conclusion: The change in contrast enhancement of HCC seen on the 1-month follow-up CT in patients after local RT may be used as an early predictor of final treatment response.

Processing and evaluation of image matching tools in radiotherapy

International Nuclear Information System (INIS)

Bondiau, P.Y.

2004-11-01

Cancer is a major problem of public health. Treatment can be done in a general or loco-regional way, in this last case medical images are important as they specify the localization of the tumour. The objective of the radiotherapy is to deliver a curative dose of radiation in the target volume while sparing the organs at risks (O.A.R.). The determination of the accurate localization of the targets volume as well as O.A.R. make it possible to define the ballistic of irradiation beams. After the description of the principles of radiotherapy and cancers treatment, we specify the clinical stakes of ocular, cerebral and prostatic tumours. We present a state of the art of image matching, the various techniques reviewed with an aim of being didactic with respect to the medical community. The results of matching are presented within the framework of the planning of the cerebral and prostatic radiotherapy in order to specify the types of applicable matching in oncology and more particularly in radiotherapy. Then, we present the prospects for this type of application according to various anatomical areas. Applications of automatic segmentation and the evaluation of the results in the framework of brain tumour are described after a review of the various segmentation methods according to anatomical localizations. We will see an original application: the digital simulation of the virtual tumoral growth and the comparison with the real growth of a cerebral tumour presented by a patient. Lastly, we will expose the future developments possible of the tools for image processing in radiotherapy as well as the tracks of research to be explored in oncology. (author)

Dosimetric comparison of standard bi-dimensional radiotherapy, mono-isocentric three-dimensional and arc-therapy for a bilateral breast cancer case with ganglionary attack; Comparaison dosimetrique pour un cas de cancer du sein bilateral avec atteinte ganglionnaire de la radiotherapie bidimensionnelle standard, la radiotherapie tridimensionnelle mono-isocentrique et l'arctherapie

Energy Technology Data Exchange (ETDEWEB)

Arnaud, A. [Centre Leon-Berard, Lyon (France); Bodez, V.; Alric, K.; Chastel, D.; Mege, A. [Institut Sainte-Catherine, Avignon (France)

2011-10-15

The authors report a study which aimed at determining the optimal radiotherapy technique for a patient operated from a bilateral breast cancer with ganglionary attack and peculiar thoracic conformation. A dosimetric study has been performed. Target volumes and lung and heart coverages have been compared for three techniques: bi-dimensional and three-dimensional radiotherapy, and arc-therapy. It appears that arc-therapy would allow a dosimetric and therapeutic duration gain without improving the target volume coverage while increasing doses delivered to organs at risk. Short communication

[Porting Radiotherapy Software of Varian to Cloud Platform].

Science.gov (United States)

Zou, Lian; Zhang, Weisha; Liu, Xiangxiang; Xie, Zhao; Xie, Yaoqin

2017-09-30

To develop a low-cost private cloud platform of radiotherapy software. First, a private cloud platform which was based on OpenStack and the virtual GPU hardware was builded. Then on the private cloud platform, all the Varian radiotherapy software modules were installed to the virtual machine, and the corresponding function configuration was completed. Finally the software on the cloud was able to be accessed by virtual desktop client. The function test results of the cloud workstation show that a cloud workstation is equivalent to an isolated physical workstation, and any clients on the LAN can use the cloud workstation smoothly. The cloud platform transplantation in this study is economical and practical. The project not only improves the utilization rates of radiotherapy software, but also makes it possible that the cloud computing technology can expand its applications to the field of radiation oncology.

DEGRO practical guidelines: radiotherapy of breast cancer III - radiotherapy of the lymphatic pathways

International Nuclear Information System (INIS)

Sautter-Bihl, M.L.; Sedlmayer, F.; Fussl, C.; Budach, W.; Dunst, J.; Feyer, P.; Fietkau, R.; Sauer, R.; Harms, W.; Piroth, M.D.; Souchon, R.; Wenz, F.; Haase, W.

2014-01-01

The purpose of this work is to update the practical guidelines for adjuvant radiotherapy of the regional lymphatics of breast cancer published in 2008 by the breast cancer expert panel of the German Society of Radiation Oncology (DEGRO). A comprehensive survey of the literature concerning regional nodal irradiation (RNI) was performed using the following search terms: ''breast cancer'', ''radiotherapy'', ''regional node irradiation''. Recent randomized trials were analyzed for outcome as well as for differences in target definition. Field arrangements in the different studies were reproduced and superimposed on CT slices with individually contoured node areas. Moreover, data from recently published meta-analyses and guidelines of international breast cancer societies, yielding new aspects compared to 2008, provided the basis for defining recommendations according to the criteria of evidence-based medicine. In addition to the more general statements of the German interdisciplinary S3 guidelines updated in 2012, this paper addresses indications, targeting, and techniques of radiotherapy of the lymphatic pathways after surgery for breast cancer. International guidelines reveal substantial differences regarding indications for RNI. Patients with 1-3 positive nodes seem to profit from RNI compared to whole breast (WBI) or chest wall irradiation alone, both with regard to locoregional control and disease-free survival. Irradiation of the regional lymphatics including axillary, supraclavicular, and internal mammary nodes provided a small but significant survival benefit in recent randomized trials and one meta-analysis. Lymph node irradiation yields comparable tumor control in comparison to axillary lymph node dissection (ALND), while reducing the rate of lymph edema. Data concerning the impact of 1-2 macroscopically affected sentinel node (SN) or microscopic metastases on prognosis are conflicting. Recent data suggest that the current restrictive use of RNI should be

Final report on the Magnetized Target Fusion Collaboration

Energy Technology Data Exchange (ETDEWEB)

John Slough

2009-09-08

1 meter, and the time from the initiation of formation to the establishment of the final equilibrium was less than 10 microseconds. With some modification, each accelerator was made capable of producing FRCs suitable for the production of the target plasma for the MTF liner experiment. Based on the initial FRC merging/compression results, the design and methodology for an experimental realization of the target plasma for the MTF liner experiment can now be defined. A high density FRC plasmoid is to be formed and accelerated out of each IPA into a merging/compression chamber similar to the imploding liner at AFRL. The properties of the resultant FRC plasma (size, temperature, density, flux, lifetime) are obtained in the reevant regime of interest. The process still needs to be optimized, and a final design for implementation at AFRL must now be carried out. When implemented at AFRL it is anticipated that the colliding/merging FRCs will then be compressed by the liner. In this manner it is hoped that ultimately a plasma with ion temperatures reaching the 10 keV range and fusion gain near unity can be obtained.

Accuracy verification of PET-CT image fusion and its utilization in target delineation of radiotherapy

International Nuclear Information System (INIS)

Wang Xuetao; Yu Jinming; Yang Guoren; Gong Heyi

2005-01-01

Objective: Evaluate the accuracy of co-registration of PET and CT (PET-CT) images on line with phantom, and utilize it on patients to provide clinical evidence for target delineation in radiotherapy. Methods: A phantom with markers and different volume cylinders was infused with various concentrations of 18 FDG, and scanned at 4 mm by PET and CT respectively. After having been transmitted into GE eNTEGRA and treatment planning system (TPS) workstations, the images were fused and reconstructed. The distance between the markers and the errors were monitored in PET and CT images respectively. The volume of cylinder in PET and CT images were measured and compared by certain pixel value proportion deduction method. The same procedure was performed on the pulmonary tumor image in ten patients. Results: eNTEGRA and TPS workstations had a good length linearity, but the fusion error of the latter was markedly greater than the former. Tumors in different volume filled by varying concentrations of 18 FDG required different pixel deduction proportion. The cylinder volume of PET and CT images were almost the same, so were the images of pulmonary tumor of ten patients. Conclusions: The accuracy of image co-registration of PET-CT on line may fulfill the clinical demand. Pixel value proportion deduction method can be used for target delineation on PET image. (authors)

Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy.

Science.gov (United States)

Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

2016-02-27

Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

2016-01-01

Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

Effect of radiotherapy on immunity function of cancer patients receiving radiotherapy

International Nuclear Information System (INIS)

Li Xinli; Zhu Shentao; Xu Jiuhong

2003-01-01

Objective: In order to observe the effect of radiotherapy on immunity function of cancer patients receiving radiotherapy. Methods: Cellular immunity is determined by APAAP; Humoral immunity is determined by transmission method. Results: The items of cellular immunity is lower than the control after radiotherapy. These items decrease continually. The difference between before and after radiotherapy has statistic significance. Of all Humoral immunity items, IgA, IgM decreased after radiotherapy and the difference has statistic significance. Conclusions: Radiotherapy can damage patients' immunity function

Clinical Applications of 3-D Conformal Radiotherapy

Science.gov (United States)

Miralbell, Raymond

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

A strategy to objectively evaluate the necessity of correcting detected target deviations in image guided radiotherapy

International Nuclear Information System (INIS)

Yue, Ning J.; Kim, Sung; Jabbour, Salma; Narra, Venkat; Haffty, Bruce G.

2007-01-01

Image guided radiotherapy technologies are being increasingly utilized in the treatment of various cancers. These technologies have enhanced the ability to detect temporal and spatial deviations of the target volume relative to planned radiation beams. Correcting these detected deviations may, in principle, improve the accuracy of dose delivery to the target. However, in many situations, a clinical decision has to be made as to whether it is necessary to correct some of the deviations since the relevant dosimetric impact may or may not be significant, and the corresponding corrective action may be either impractical or time consuming. Ideally this decision should be based on objective and reproducible criteria rather than subjective judgment. In this study, a strategy is proposed for the objective evaluation of the necessity of deviation correction during the treatment verification process. At the treatment stage, without any alteration from the planned beams, the treatment beams should provide the desired dose coverage to the geometric volume identical to the planning target volume (PTV). Given this fact, the planned dose distribution and PTV geometry were used to compute the dose coverage and PTV enclosure of the clinical target volume (CTV) that was detected from imaging during the treatment setup verification. The spatial differences between the detected CTV and the planning CTV are essentially the target deviations. The extent of the PTV enclosure of the detected CTV as well as its dose coverage were used as criteria to evaluate the necessity of correcting any of the target deviations. This strategy, in principle, should be applicable to any type of target deviations, including both target deformable and positional changes and should be independent of how the deviations are detected. The proposed strategy was used on two clinical prostate cancer cases. In both cases, gold markers were implanted inside the prostate for the purpose of treatment setup

Effects of radiotherapy in the treatment of multiple myeloma

International Nuclear Information System (INIS)

Ochtrop, Thomas Alexander

2015-01-01

Palliative irradiation of osteolytic lesions is a considerable component in the treatment for patients with multiple myeloma. In this study, we analyzed the efficacy of irradiation in these patients. Patients and methods: We retrospectively analyzed 153 patients with multiple myeloma who were admitted to our department between 1989 and 2013. According to the staging system of Durie and Salmon 116 patients were classified as stage III. 107/153 patients were treated with radiotherapy of at least one and up to 6 bony lesions at different times. In order to evaluate the effect of local radiotherapy on pain relief and bone recalcification a uni- and multivariate analysis was performed using a binary logistic regression model to correct for multiple measurements. Complete information on dose, fractionation and volume of radiotherapy was available from 81 patients treated in 136 target volumes for pain relief, and from 69 patients treated in 108 target volumes for recalcification. Total radiation doses varied between 8 Gy to 50 Gy (median dose 25 Gy in 2.5 Gy fractions, 5 times a week). Results: Radiotherapy resulted in complete local pain relief in 31% and partial local pain relief in 54% of the patients. In the univariate analysis, higher total radiation doses (p = 0.023) and higher age (p = 0.014) at the time of radiotherapy were significantly associated with a higher likelihood of pain relief, whereas no significant association was detected for concurrent systemic treatment, type and stage of myeloma and location of bone lesions. The same variables were independent predictors for pain relief in the multivariate analysis. Recalcification was observed in 48% of irradiated bone lesions. In the uni- and multivariate analysis higher radiation doses were significantly associated (p = 0.048) with an increased likelihood of recalcification. Side effects of radiotherapy were generally mild. Conclusions: Higher total biological radiation doses were associated with better pain

Planning target volumes for radiotherapy: how much margin is needed?

International Nuclear Information System (INIS)

Antolak, John A.; Rosen, Isaac I.

1999-01-01

Purpose: The radiotherapy planning target volume (PTV) encloses the clinical target volume (CTV) with anisotropic margins to account for possible uncertainties in beam alignment, patient positioning, organ motion, and organ deformation. Ideally, the CTV-PTV margin should be determined solely by the magnitudes of the uncertainties involved. In practice, the clinician usually also considers doses to abutting healthy tissues when deciding on the size of the CTV-PTV margin. This study calculates the ideal size of the CTV-PTV margin when only physical position uncertainties are considered. Methods and Materials: The position of the CTV for any treatment is assumed to be described by independent Gaussian distributions in each of the three Cartesian directions. Three strategies for choosing a CTV-PTV margin are analyzed. The CTV-PTV margin can be based on: 1. the probability that the CTV is completely enclosed by the PTV; 2. the probability that the projection of the CTV in the beam's eye view (BEV) is completely enclosed by the projection of the PTV in the BEV; and 3. the probability that a point on the edge of the CTV is within the PTV. Cumulative probability distributions are derived for each of the above strategies. Results: Expansion of the CTV by 1 standard deviation (SD) in each direction results in the CTV being entirely enclosed within the PTV 24% of the time; the BEV projection of the CTV is enclosed within the BEV projection of the PTV 39% of the time; and a point on the edge of the CTV is within the PTV 84% of the time. To have the CTV enclosed entirely within the PTV 95% of the time requires a margin of 2.8 SD. For the BEV projection of the CTV to be within the BEV projection of the PTV 95% of the time requires a margin of 2.45 SD. To have any point on the surface of the CTV be within the PTV 95% of the time requires a margin of 1.65 SD. Conclusion: In the first two strategies for selecting a margin, the probability of finding the CTV within the PTV is

Radiotherapy in desmoid tumors. Treatment response, local control, and analysis of local failures

Energy Technology Data Exchange (ETDEWEB)

Santti, Kirsi; Beule, Annette; Tuomikoski, Laura; Jaeaeskelaeinen, Anna-Stina; Saarilahti, Kauko; Tarkkanen, Maija; Blomqvist, Carl [Helsinki University Hospital and University of Helsinki, Comprehensive Cancer Center, Helsinki (Finland); Roenty, Mikko [HUSLAB and University of Helsinki, Department of Pathology, Helsinki (Finland); Ihalainen, Hanna [Helsinki University Hospital and University of Helsinki, Department of Plastic Surgery, Helsinki (Finland)

2017-04-15

Desmoid tumors (aggressive fibromatosis) are rare soft tissue tumors which frequently recur after surgery. Desmoid tumors arise from musculoaponeurotic tissue in the extremities, head and neck, abdominal wall, or intra-abdominally. Our aim was to examine the outcome of radiotherapy of desmoid tumors in a single institution series. We evaluated 41 patients with desmoid tumors treated with 49 radiotherapies between 1987 and 2012. Radiologic images for response evaluation were reassessed and responses to treatment registered according to RECIST criteria 1.1. For patients with local failures radiation dose distribution was determined in each local failure volume using image co-registration. Recurrences were classified as in-target, marginal, or out-of-target. Prognostic factors for radiotherapy treatment failure were evaluated. Radiotherapy doses varied from 20-63 Gy (median 50 Gy) with a median fraction size of 2 Gy. The objective response rate to definitive radiotherapy was 55% (12/22 patients). Median time to response was 14 months. A statistically significant dose-response relation for definitive and postoperative radiotherapy was observed both in univariate (p-value 0.002) and in multivariate analysis (p-value 0.02) adjusted for potential confounding factors. Surgery before radiotherapy or surgical margin had no significant effect on time to progression. Nine of 11 (82%) local failures were classified as marginal and two of 11 (18%) in-target. None of the recurrences occurred totally out-of-target. Radiotherapy is a valuable option for treating desmoid tumors. Radiotherapy dose appears to be significantly associated to local control. (orig.) [German] Desmoide (aggressive Fibromatosen) sind seltene Weichteiltumore der muskulaeren Membranen von Kopf, Hals, Extremitaeten und Bauchwand. Ziel war es, die Wirksamkeit der Strahlentherapie bei aggressiver Fibromatose an einer einzelnen Klinik zu untersuchen. Ausgewertet wurden 41 Patienten mit aggressiver Fibromatose, die

Processing and evaluation of image matching tools in radiotherapy; Mise en oeuvre et evaluation d'outils de fusion d'image en radiotherapie

Energy Technology Data Exchange (ETDEWEB)

Bondiau, P.Y

2004-11-15

Cancer is a major problem of public health. Treatment can be done in a general or loco-regional way, in this last case medical images are important as they specify the localization of the tumour. The objective of the radiotherapy is to deliver a curative dose of radiation in the target volume while sparing the organs at risks (O.A.R.). The determination of the accurate localization of the targets volume as well as O.A.R. make it possible to define the ballistic of irradiation beams. After the description of the principles of radiotherapy and cancers treatment, we specify the clinical stakes of ocular, cerebral and prostatic tumours. We present a state of the art of image matching, the various techniques reviewed with an aim of being didactic with respect to the medical community. The results of matching are presented within the framework of the planning of the cerebral and prostatic radiotherapy in order to specify the types of applicable matching in oncology and more particularly in radiotherapy. Then, we present the prospects for this type of application according to various anatomical areas. Applications of automatic segmentation and the evaluation of the results in the framework of brain tumour are described after a review of the various segmentation methods according to anatomical localizations. We will see an original application: the digital simulation of the virtual tumoral growth and the comparison with the real growth of a cerebral tumour presented by a patient. Lastly, we will expose the future developments possible of the tools for image processing in radiotherapy as well as the tracks of research to be explored in oncology. (author)

Dosimetry applied to radiology and radiotherapy

International Nuclear Information System (INIS)

Yoshimura, Elisabeth Mateus

2010-01-01

Full text. The uses of ionizing radiation in medicine are increasing worldwide, and the population doses increase as well. The actual radiation protection philosophy is based on the balance of risks and benefits related to the practices, and patient dosimetry has an important role in the implementation of this point of view. In radiology the goal is to obtain an image with diagnostic quality with the minimum patient dose. In modern Radiotherapy the cure indexes are higher, giving rise to longer survival times to the patients. Dosimetry in radiotherapy helps the treatment planning systems to get a better protection to critical organs, with higher doses to the tumor, with a guarantee of better life quality to the patient. We will talk about the new trends in dosimetry of medical procedures, including experimental techniques and calculation tools developed to increase reliability and precision of dose determination. In radiology the main concerns of dosimetry are: the transition from film- radiography to digital image, the pediatric patient doses, and the choice of dosimetric quantities to quantify fluoroscopy and tomography patient doses. As far as Radiotherapy is concerned, there is a search for good experimental techniques to quantify doses to tissues adjacent to the target volumes in patients treated with new radiotherapy techniques, as IMRT and heavy particle therapy. (author)

Phantom study of radiation doses outside the target volume brachytherapy versus external radiotherapy of early breast cancer

International Nuclear Information System (INIS)

Johansson, Bengt; Persson, Essie; Westman, Gunnar; Persliden, Jan

2003-01-01

Background and purpose: Brachytherapy is sometimes suggested as an adjuvant treatment after surgery of some tumours. When introducing this, it would be useful to have an estimate of the dose distribution to different body sites, both near and distant to target, comparing conventional external irradiation to brachytherapy. The aim of the present study was to determine radiation doses with both methods at different body sites, near and distant to target, in an experimental situation on an operated left sided breast cancer on a female Alderson phantom. Methods: Five external beam treatments with isocentric tangential fields were given by a linear accelerator. A specified dose of 1.0 Gy was given to the whole left sided breast volume. Five interstitial brachytherapy treatments were given to the upper, lateral quadrant of the left breast by a two plane, 10 needles implant. A dose of 1.0 Gy specified according to the Paris system was administered by a pulsed dose rate afterloading machine. Absorbed dose in different fixed dose points were measured by thermoluminescence dosimeters. Results: Both methods yielded an absorbed dose of the same size to the bone marrow and internal organs distant to target, 1.0-1.4% of the prescribed dose. There was a trend of lower doses to the lower half of the trunk and higher doses to the upper half of the trunk, respectively, by brachytherapy. A 90% reduction of absorbed dose with brachytherapy compared to external irradiation was found in the near-target region within 5 cm from target boundary where parts of the left lung and the heart are situated. If an adjuvant dose of 50 Gy is given with the external radiotherapy and brachytherapy, the absorbed dose in a part of the myocardium could be reduced from 31.8 to 2.1 Gy. Conclusions: Near target, brachytherapy yielded a considerably lower absorbed dose which is of special importance when considering radiation effects on the myocard and lungs. We could not demonstrate any difference of

Extracranial stereotactic radiotherapy: Evaluation of PTV coverage and dose conformity

International Nuclear Information System (INIS)

Haedinger, U.; Thiele, W.; Wulf, J.

2002-01-01

During the past few years the concept of cranial sterotactic radiotherapy has been successfully extended to extracranial tumoral targets. In our department, hypofractionated treatment of tumours in lung, liver, abdomen, and pelvis is performed in the Stereotactic Body Frame (ELEKTA Instrument AB) since 1997. We present the evaluation of 63 consecutively treated targets (22 lung, 21 liver, 20 abdomen/pelvis) in 58 patients with respect to dose coverage of the planning target volume (PTV) as well as conformity of the dose distribution. The mean PTV coverage was found to be 96.3%±2.3% (lung), 95.0%±4.5% (liver), and 92.1%±5.2% (abdomen/pelvis). For the so-called conformation number we obtained values of 0.73±0.09 (lung), 0.77±0.10 (liver), and 0.70±0.08 (abdomen/pelvis). The results show that highly conformal treatment techniques can be applied also in extracranial stereotactic radiotherapy. This is primarily due to the relatively simple geometrical shape of most of the targets. Especially lung and liver targets turned out to be approximately spherically/cylindrically shaped, so that the dose distribution can be easily tailored by rotational fields. (orig.) [de

A multicentre 'end to end' dosimetry audit of motion management (4DCT-defined motion envelope) in radiotherapy.

Science.gov (United States)

Palmer, Antony L; Nash, David; Kearton, John R; Jafari, Shakardokht M; Muscat, Sarah

2017-12-01

External dosimetry audit is valuable for the assurance of radiotherapy quality. However, motion management has not been rigorously audited, despite its complexity and importance for accuracy. We describe the first end-to-end dosimetry audit for non-SABR (stereotactic ablative body radiotherapy) lung treatments, measuring dose accumulation in a moving target, and assessing adequacy of target dose coverage. A respiratory motion lung-phantom with custom-designed insert was used. Dose was measured with radiochromic film, employing triple-channel dosimetry and uncertainty reduction. The host's 4DCT scan, outlining and planning techniques were used. Measurements with the phantom static and then moving at treatment delivery separated inherent treatment uncertainties from motion effects. Calculated and measured dose distributions were compared by isodose overlay, gamma analysis, and we introduce the concept of 'dose plane histograms' for clinically relevant interpretation of film dosimetry. 12 radiotherapy centres and 19 plans were audited: conformal, IMRT (intensity modulated radiotherapy) and VMAT (volumetric modulated radiotherapy). Excellent agreement between planned and static-phantom results were seen (mean gamma pass 98.7% at 3% 2 mm). Dose blurring was evident in the moving-phantom measurements (mean gamma pass 88.2% at 3% 2 mm). Planning techniques for motion management were adequate to deliver the intended moving-target dose coverage. A novel, clinically-relevant, end-to-end dosimetry audit of motion management strategies in radiotherapy is reported. Copyright © 2017 Elsevier B.V. All rights reserved.

Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1-2 Glottic Cancer

International Nuclear Information System (INIS)

Rosenthal, David I.; Fuller, Clifton D.; Barker, Jerry L.; Mason, Bryan M.S.; Garcia, John A. C.; Lewin, Jan S.; Holsinger, F. Christopher; Stasney, C. Richard; Frank, Steven J.; Schwartz, David L.; Morrison, William H.; Garden, Adam S.; Ang, K. Kian

2010-01-01

Purpose: To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials: Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1-2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose-volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results: Intensity-modulated radiotherapy consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions: Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.

Radiotherapy quality insurance by individualized in vivo dosimetry: state of the art; Dosimetrie individuelle in vivo pour le controle de qualite en radiotherapie: etat de l'art

Energy Technology Data Exchange (ETDEWEB)

Ismail, A.; Giraud, J.Y.; Sihanath, R.; Balosso, J. [University Hospital of Grenoble, Dept. of Radiotherapy, 38 - Grenoble (France); Ismail, A. [Syrian Atomic Energy Commission, Radioprotection Dept., Damascus (Syrian Arab Republic); Luc, G.N.; Pittet, P.; Galvanc, J.M. [Claude-Bernard Univ., Lyon Nanotechnology Institute, 69 - Lyon (France)

2009-06-15

The quality insurance in radiotherapy in the frame of highly complex technical process as Intensity modulated radiotherapy (I.M.R.T.) needs independent control of the delivered dose to the patient. Actually, up to now, most of the radiotherapy treatments rely only on computed dosimetry through a rather complicated series of linked simulation tool. This dosimetry approach requires also qualified treatment means based on cautious quality insurance procedures. However, erroneous parameters could be difficult to detect and systematical errors could happen leading to radiotherapy accidents. In this context, in vivo dosimetry has a critical role of final control of the delivered dose. As many beam incidences and ports are used for any photon therapy treatment, external control could be very tedious and time consuming. Therefore, innovations are needed for in vivo dosimetry to provide ergonomic and efficient tools for these controls. This paper presents a review of technologies and products that can be used for in vivo dosimetry. It proposes also a reflection on the concepts to develop future devices suitable for this purpose. The technical means with their physical principles are reviewed, the clinical experiences demonstrating the feasibility of new techniques are then summarized and finally, the early clinical use and its impact on clinical practice is review. (authors)

Integration of molecular imaging in treatment planning and delivery of modern radiotherapy

International Nuclear Information System (INIS)

Jacob, V.; Wilkens, J.J.

2011-01-01

Among various imaging modalities currently available, positron emission tomography (PET) has the potential to visualize processes on a molecular level. Molecular imaging, often also referred to as functional or biological imaging, brought a new dimension to diagnostics and therapy of cancer by providing images of metabolism and other processes in the human body and in tumours. PET was first applied for diagnostics and staging of various tumours with high diagnostic precision. Modern radiotherapy asks increasingly for individualized treatment strategies, taking molecular imaging into account. Technical developments over the last years, in particular methods to register various imaging modalities within software packages for treatment planning and target delineation, facilitated the use of PET imaging in radiotherapy. In order to exploit the full potential of modern high-precision radiotherapy, exact imaging procedures are necessary, for example for precise target volume definition. In the long run, concepts employing an inhomogeneous dose prescription based on biological imaging may become routine in clinical applications, leading to individualized, biologically adaptive therapy. (orig.)

Comparison of Heart and Coronary Artery Doses Associated With Intensity-Modulated Radiotherapy Versus Three-Dimensional Conformal Radiotherapy for Distal Esophageal Cancer

Energy Technology Data Exchange (ETDEWEB)

Kole, Thomas P.; Aghayere, Osarhieme; Kwah, Jason [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yorke, Ellen D. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Goodman, Karyn A., E-mail: goodmank@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2012-08-01

Purpose: To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Methods and Materials: Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters were statistically evaluated using the Wilcoxon rank-sum test. Results: Intensity-modulated radiotherapy treatment planning showed significant reduction (p < 0.05) in heart dose over 3D-CRT as assessed by average mean dose (22.9 vs. 28.2 Gy) and V30 (24.8% vs. 61.0%). There was also significant sparing of the right coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Conclusions: Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D

Neural Stem Cell-Preserving External-Beam Radiotherapy of Central Nervous System Malignancies

International Nuclear Information System (INIS)

Barani, Igor J.; Cuttino, Laurie W.; Benedict, Stanley H.; Todor, Dorin; Bump, Edward A.; Wu Yan; Chung, Theodore D.; Broaddus, William C.; Lin, Peck-Sun

2007-01-01

Purpose: Recent discoveries have implicated neural stem cells (NSC) as the source of plasticity and repair in the mature mammalian brain. Treatment-induced NSC dysfunction may lead to observed toxicity. This study evaluates the feasibility of NSC-preserving external beam radiotherapy. Methods and Materials: A single computed tomography (CT) dataset depicting a right periventricular lesion was used in this study as this location reflects the most problematic geometric arrangement with respect to NSC preservation. Conventional and NSC preserving radiotherapy (RT) plans were generated for the same lesion using two clinical scenarios: cerebral metastatic disease and primary high-grade glioma. Disease-specific target volumes were used. Metastatic disease was conventionally treated with whole-brain radiotherapy (WBRT) to 3,750 cGy (15 fractions) followed by a single stereotactic radiosurgery (SRS) boost of 1,800 cGy to gross disease only. High-grade glioma was treated with conventional opposed lateral and anterior superior oblique beams to 4,600 cGy (23 fractions) followed by a 1,400 cGy (7 fractions) boost. NSC preservation was achieved in both scenarios with inverse-planned intensity modulated radiotherapy (IMRT). Results: Cumulative dose reductions of 65% (metastatic disease) and 25% (high-grade glioma) to the total volume of the intracranial NSC compartments were achieved with NSC-preserving IMRT plans. The reduction of entry and exit dose to NSC niches located contralateral to the target contributed most to NSC preservation. Conclusions: Neural stem cells preservation with current external beam radiotherapy techniques is achievable in context of both metastatic brain disease and high-grade glioma, even when the target is located adjacent to a stem cell compartment. Further investigation with clinical trials is warranted to evaluate whether NSC preservation will result in reduced toxicity

An investigation of anxiety about radiotherapy deploying the radiotherapy categorical anxiety scale

International Nuclear Information System (INIS)

Shimotsu, Sakie; Karasawa, Kumiko; Ito, Kana; Saito, Anneyuko I.; Izawa, Hiromi; Kawase, Eri; Horikawa, Naoshi

2010-01-01

Radiotherapy is one of the major methods for treating cancer, but many patients undergoing radiotherapy have deep concerns about receiving radiation treatment. This problem is not generally appreciated and has not been adequately studied. The objective of this investigation was to empirically investigate the anxieties that cancer patients feel towards radiotherapy by using questionnaires to classify and quantitatively measure their concerns. A preliminary interview to develop a questionnaire was carried out with 48 patients receiving radiotherapy to discover their anxieties about on-going treatments. Subsequently, a main study was performed using a questionnaire with 185 patients to classify their types of anxiety and to ascertain the reliability and validity of the responses. Confirmatory factor analysis was then carried out with a 17-item Radiotherapy Categorical Anxiety Scale. Three anxiety factors were abstracted by factor analysis: adverse effects of radiotherapy, environment of radiotherapy, and treatment effects of radiotherapy. Reliability, content validity, and concurrent validity were obtained. The adequacy of the three-factor model of anxiety concerning radiotherapy was confirmed. A 17-item Radiotherapy Categorical Anxiety Scale was formulated to quantitatively measure the specific types of anxiety among cancer patients receiving radiotherapy. (author)

Quality of radiotherapy reporting in randomized controlled trials of prostate cancer.

Science.gov (United States)

Soon, Yu Yang; Chen, Desiree; Tan, Teng Hwee; Tey, Jeremy

2018-06-07

Good radiotherapy reporting in clinical trials of prostate radiotherapy is important because it will allow accurate reproducibility of radiotherapy treatment and minimize treatment variations that can affect patient outcomes. The aim of our study is to assess the quality of prostate radiotherapy (RT) treatment reporting in randomized controlled trials in prostate cancer. We searched MEDLINE for randomized trials of prostate cancer, published from 1996 to 2016 and included prostate RT as one of the intervention arms. We assessed if the investigators reported the ten criteria adequately in the trial reports: RT dose prescription method; RT dose-planning procedures; organs at risk (OAR) dose constraints; target volume definition, simulation procedures; treatment verification procedures; total RT dose; fractionation schedule; conduct of quality assurance (QA) as well as presence or absence of deviations in RT treatment planning and delivery. We performed multivariate logistic regression to determine the factors that may influence the quality of reporting. We found 59 eligible trials. There was significant variability in the quality of reporting. Target volume definition, total RT dose and fractionation schedule were reported adequately in 97% of included trials. OAR constraints, simulation procedures and presence or absence of deviations in RT treatment planning and delivery were reported adequately in 30% of included trials. Twenty-four trials (40%) reported seven criteria or more adequately. Multivariable logistic analysis showed that trials that published their quality assurance results and cooperative group trials were more likely to have adequate quality in reporting in at least seven criteria. There is significant variability in the quality of reporting on prostate radiotherapy treatment in randomized trials of prostate cancer. We need to have consensus guidelines to standardize the reporting of radiotherapy treatment in randomized trials.

EGFR and HER2 expression in primary cervical cancers and corresponding lymph node metastases: Implications for targeted radiotherapy

International Nuclear Information System (INIS)

Shen, Li; Shui, Yongjie; Wang, Xiaojia; Sheng, Liming; Yang, Zhengyan; Xue, Danfeng; Wei, Qichun

2008-01-01

Proteins overexpressed on the surface of tumor cells can be selectively targeted. Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are among the most often targeted proteins. The level and stability of expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target for imaging in nuclear medicine and for various forms of therapy. So far, the expression of EGFR and HER2 has only been determined in primary cervical cancers, and we have not found published data regarding the receptor status in corresponding metastatic lesions. The goal of this study was to evaluate whether any of these receptors are suitable as target for clinical diagnosis and therapy. Expression of EGFR and HER2 was investigated immunohistochemically in both lymph node metastases and corresponding primary cervical cancers (n = 53). HER2 and EGFR expression was scored using HercepTest criteria (0, 1+, 2+ or 3+). EGFR overexpression (2+ or 3+) was found in 64% (35/53) of the primary cervical tumors and 60% (32/53) of the corresponding lymph node metastases. There was a good concordance between the primary tumors and the paired metastases regarding EGFR expression. Only four patients who had 2+ or 3+ in the primary tumors changed to 0 or 1+ in lymph node metastases, and another two cases changed the other way around. None of the primary tumors or the lymph node metastases expressed HER2 protein. The EGFR expression seems to be common and stable during cervical cancer metastasis, which is encouraging for testing of EGFR targeted radiotherapy. HER2 appears to be of poor interest as a potential target in the treatment of cervical cancer

Advances in Radiotherapy for Head and Neck Cancer

NARCIS (Netherlands)

Gregoire, Vincent; Langendijk, Johannes A.; Nuyts, Sandra

2015-01-01

Over the last few decades, significant improvements have been made in the radiotherapy (RT) treatment of head and neck malignancies. The progressive introduction of intensity-modulated RT and the use of multimodality imaging for target volume and organs at risk delineation, together with the use of

The role of primary radiotherapy in acromegaly (abstract)

International Nuclear Information System (INIS)

Ali, M.; Knob, G.

1998-01-01

The aim of the study was to evaluate the role of primary radiotherapy in acromegaly. Fifteen cases were randomly included in this study from 1989 to 1998. The patients were given external radiotherapy using Co/sup 60/ source and 200 cGy/F, 5F/week up to 5000 cGy, Tumor dose (TD). The target volume was irradiated by opposite parallel lateral field. The field size ranged from 4.5 to 6.5 cm. depending upon the tumor size and its extensions. These patients were continuously followed up for variable period depending upon the history of the patient and compliance by serial Growth Hormone (GH) assay and Clinical and Radiological evaluation. Out of these fifteen patients one died of cardiac sequelae. In the remaining treated patients majority has normal or continuously decreasing GH levels. The treatment of Acromegaly includes surgery, radiotherapy, medical treatment or the combination of these with variable success and non is perfect. We used radiotherapy as the primary modality, due to medical contraindication or refusal of patient for surgery and found that this is an effective modality in the treatment of acromegaly even in patients with extra sellar extension of the tumor. (author)

Conformal radiotherapy: principles and classification

International Nuclear Information System (INIS)

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

1999-01-01

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

Conformal radiotherapy by intensity modulation of pediatrics tumors

International Nuclear Information System (INIS)

Leseur, J.; Le Prise, E.; Carrie, C.; Bernier, V.; Beneyton, V.; Mahe, M.A.; Supiot, S.

2009-01-01

The objective of this study is to take stock on the validated and potential indications of the conformal radiotherapy with intensity modulation ( intensity modulated radiotherapy I.M.R.T.) in pediatrics and to propose recommendations for its use as well as the adapted dose constraints. About 40 to 50% of children treated for a cancer are irradiated. The I.M.R.T., by linear accelerator or helical tomo-therapy has for aim to give a homogenous dose to the target volume and to save organs at risk. Its use in pediatrics seems particularly interesting because of the complexity of target volumes and the closeness of organs at risk. In compensation for these positive elements, the importance of low doses irradiation given in big volumes makes fear event consequences on growth and an increased incidence of secondary cancers in children suffering from tumors with high cure rates and long life expectancy. (N.C.)

Comparison of the predictions of the LQ and CRE models for normal tissue damage due to biologically targeted radiotherapy with exponentially decaying dose rates

International Nuclear Information System (INIS)

O'Donoghue, J.A.; West of Schotland Health Boards, Glasgow

1989-01-01

For biologically targeted radiotherapy organ dose rates may be complex functions of time, related to the biodistribution kinetics of the delivery vehicle and radiolabel. The simples situation is where dose rates are exponentially decaying functions of time. Two normal tissue isoeffect models enable the effects of exponentially decaying dose rates to be addressed. These are the extension of the linear-quadratic model and the cumulative radiation effect model. This communication will compare the predictions of these models. (author). 14 refs.; 1 fig

Radiotherapy of bronchogenic carcinoma

International Nuclear Information System (INIS)

Heilmann, H.P.

1982-01-01

Radiotherapy of branchogenic carcinoma comprises; palliative treatment, postoperative or pre-operative radiotherapy, radiotherapy as part of a combination of chemotherapy and radiotherapy of small cell carcinoma and curative radiotherapy of non-operable non-small cell carcinoma. Atelectasis and obstruction are indications for palliative radiotherapy. Postoperative radiotherapy is given only in cases of incomplete resection or mediastinal metastases. In the treatment of small cell carcinoma by combined irradiation and chemotherapy the mediastinum and primary tumour are irradiated, generally after chemotherapy, and the C.N.S. receives prophylactic radiotherapy. Curative radiotherapy is indicated in cases of non-operable small cell carcinoma. Irradiation with doses of 60-70 Gy produced 5-years-survival rates of 10-14% in cases classified as T 1 -T 2 N 0 M 0 . (orig.) [de

An Investigation of Methods for CT Synthesis in MR-only Radiotherapy

DEFF Research Database (Denmark)

Andreasen, Daniel

In recent years, the interest in using magnetic resonance (MR) imaging in radiotherapy (RT) has increased. This is because MR has a superior soft tissue contrast compared to computed tomography (CT), which makes it a better modality for delineating the target volume (tumor) and possible organs...... at risk (OARs). In an MR/CT work-flow, independent MR and CT scans are acquired. The target and possible OARs are delineated on the MR and then transferred to CT by aligning the data using a registration. This introduces the risk of systematic registration errors especially in non-rigid body structures......, the consequence being a systematic miss of target or increased dose to healthy tissue. Radiotherapy based on MR as the only modality removes this uncertainty and simplifies the clinical work-flow. However, the information on electron density which is usually contained in the CT must now be derived from the MR...

Targeted radiotherapy with 177 Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

International Nuclear Information System (INIS)

Rodriguez C, J.; Murphy, C.A. de; Pedraza L, M.; Ferro F, G.; Murphy S, E.

2006-01-01

Malignant pancreas tumours induced in athymic mice are a good model for peptide receptor targeted radiotherapy. The objective of this research was to estimate pancreatic tumour absorbed radiation doses after administration of 177 Lu-DOTA-TATE in mice as a therapeutic radiopharmaceutical that could be used in humans. AR42J murine pancreas cancer cells expressing somatostatin receptors, were implanted in athymic mice (n=18) to obtain the 177 Lu-DOTA-TATE biokinetics and dosimetry. To estimate its therapeutic efficacy 87 MBq were injected in a tail vein of 3 mice and 19 days p.i. there were a partial relapse. There was an epithelial and sarcoma mixed tumour in the kidneys of mouse III. The absorbed dose to tumour, kidney and pancreas was 50.5 ± 7.2 Gy, 17.5 ± 2.5 Gy and 12.6 ± 2.3 Gy respectively. These studies justify further therapeutic and dosimetry estimations to ensure that 177 Lu-DOTA-TATE will act as expected in man considering its kidney radiotoxicity. (Author)

Target volume definition for external beam partial breast radiotherapy: Clinical, pathological and technical studies informing current approaches

International Nuclear Information System (INIS)

Kirby, Anna M.; Coles, Charlotte E.; Yarnold, John R.

2010-01-01

Partial breast irradiation (PBI) is currently under investigation in several phase III trials and, following a recent consensus statement, its use off-study may increase despite ongoing uncertainty regarding optimal target volume definition. We review the clinical, pathological and technical evidence for target volume definition in external beam partial breast irradiation (EB-PBI). The optimal method of tumour bed (TB) delineation requires X-ray CT imaging of implanted excision cavity wall markers. The definition of clinical target volume (CTV) as TB plus concentric 15 mm margins is based on the anatomical distribution of multifocal and multicentric disease around the primary tumour in mastectomy specimens, and the clinical locations of local tumour relapse (LR) after breast conservation surgery. If the majority of LR originate from foci of residual invasive and/or intraduct disease in the vicinity of the TB after complete microscopic resection, CTV margin logically takes account of the position of primary tumour within the surgical resection specimen. The uncertain significance of independent primary tumours as sources of preventable LR, and of wound healing responses in stimulating LR, increases the difficulties in defining optimal CTV. These uncertainties may resolve after long-term follow-up of current PBI trials. By contrast, a commonly used 10 mm clinical to planning target volume (PTV) margin has a stronger evidence base, although departmental set-up errors need to be confirmed locally. A CTV-PTV margin >10 mm may be required in women with larger breasts and/or large seromas, whilst the role of image-guided radiotherapy with or without TB markers in reducing CTV-PTV margins needs to be explored.

Radiotherapy physics

International Nuclear Information System (INIS)

Chen, G.T.Y.; Collier, J.M.; Lyman, J.T.; Pitluck, S.

1982-01-01

The Radiotherapy Physics Group works on the physical and biophysical aspects of charged particle radiotherapy. Our activities include the development of isosurvival beams (beams of uniform biological effect), computerized treatment planning development for charged particle radiotherapy, design of compensation to shape dose distributions, and development of dosimetry techniques to verify planned irradiations in both phantoms and patients

Development and clinical application of In Vivo dosimetry for radiotherapy

International Nuclear Information System (INIS)

Honda, Hirofumi; Oita, Masataka; Tominaga, Masahide; Oto, Yoshihiro

2016-01-01

In practical radiotherapy, it is important to deliver radiation to the target correctly and safely according to the treatment planning. The control of radiation dose delivered to each patient in radiotherapy mainly relies on the prediction based on the result of pre-treatment verification and irradiation accuracy of treatment machines. In Vivo dosimetry in radiotherapy is the procedure of quality assurance by the way of direct measurement for the patient whether the calculated prescribed dose in the treatment planning is delivered precisely. The history of In Vivo dosimetry is relatively long, and the TLD dosimetry for clinical radiotherapy started in early 1970's. After 1980's, owing to the development of semiconductor devices such as diode detectors, semiconductor arrays, the clinical applications for the dosimetry and diagnostic radiation imaging devices which contributed to the development of electric portal imaging devices and 2D semiconductor detectors were introduced. In recent years, these radiation measurement devices and non-invasive methods have been developed, they are becoming widespread as clinical practice. In this paper, we reviewed the In Vivo dosimetry devices and their characteristics, and technical application for radiotherapy. (author)

Preclinical evaluation of intraoperative low-energy photon radiotherapy using sphericalapplicators in locally advanced prostate cancer

Directory of Open Access Journals (Sweden)

François eBuge

2015-09-01

Full Text Available Background: Surgery plus adjuvant radiotherapy is standard care for locally advanced prostatecancer (stage pT3R1. Intraoperative low-energy photon radiotherapy offers several advantages overexternal beam radiotherapy, and several systems are now available for its delivery, using sphericalapplicators which require only limited shielding. The aim of this study was to evaluate the feasibilityof this technique for the prostate bed.Materials & Methods: Applicators were assessed using MRI image data and cadavericdissection. In cadavers, targeted tissues, defined as a urethral section, both neurovascular bundlesections, the bladder neck and the beds of the seminal vesicles, were marked with metallic surgicalclips. Distances between clips and applicator were measured using CT. A dosimetric study of theapplication of 12 Gy at 5mm depth was performed using CT images of prostatectomized cadavers.Results: Using MRI images from 34 prostate cancer patients, we showed that the ideal applicatordiameter ranges from 45 to 70 mm. Using applicators of different sizes to encompass the prostate bedin nine cadavers, we showed that the distance between target tissues and applicator was less than 2mm for all target tissues except the upper extremity of the seminal vesicles (19 mm. Dosimetric studyshowed a good dose distribution in all target tissues in contact with the applicator, with a lowprobability of rectum and bladder complication.Conclusions: Intraoperative radiotherapy of the prostate bed is feasible, with good coverage oftargeted tissues. Clinical study of safety and efficacy is now required.

Consideration of margins for hypo fractionated radiotherapy

International Nuclear Information System (INIS)

Herschtal, A.; Foroudi, F.; Kron, T.

2010-01-01

Full text: Geographical misses of the tumour are of concern in radiotherapy and are typically accommodated by introducing margins around the target. However, there is a trade-off between ensuring the target receives sufficient dose and minimising the dose to surrounding normal structures. Several methods of determining margin width have been developed with the most commonly used one proposed by M. VanHerk (VanHerk UROBP 52: 1407, 2002). VanHerk's model sets margins to achieve 95% of dose coverage for the target in 90% of patients. However, this model was derived assuming an infinite number of fractions. The aim of the present work is to estimate the modifications necessary to the model if a finite number of fractions are given. Software simulations were used to determine the true probability of a patient achieving 95% target coverage if different fraction numbers are used for a given margin width. Model parameters were informed by a large data set recently acquired at our institution using daily image guidance for prostate cancer patients with implanted fiducial markers. Assuming a 3 mm penumbral width it was found that using the VanHerk model only 74 or 54% of patients receive 95% of the prescription dose if 20 or 6 fractions are given, respectively. The steep dose gradients afforded by IMRT are likely to make consideration of the effects of hypofractionation more important. It is necessary to increase the margins around the target to ensure adequate tumour coverage if hypofractionated radiotherapy is to be used for cancer treatment. (author)

Clinical Studies on conformal radiotherapy combined with epidermal ...

African Journals Online (AJOL)

in second-line treatment of non-small cell lung cancer ... receptor-tyrosine kinase inhibitor (EGFR-TKI) in the second-line treatment of non-small cell ... were divided into two groups: 106 patients were treated with conformal ... Conformal radiotherapy, Targeted therapy, Survival rate .... regression model was used for survival.

A new methodological approach for PET implementation in radiotherapy treatment planning.

Science.gov (United States)

Bellan, Elena; Ferretti, Alice; Capirci, Carlo; Grassetto, Gaia; Gava, Marcello; Chondrogiannis, Sotirios; Virdis, Graziella; Marzola, Maria Cristina; Massaro, Arianna; Rubello, Domenico; Nibale, Otello

2012-05-01

In this paper, a new methodological approach to using PET information in radiotherapy treatment planning has been discussed. Computed tomography (CT) represents the primary modality to plan personalized radiation treatment, because it provides the basic electron density map for correct dose calculation. If PET scanning is also performed it is typically coregistered with the CT study. This operation can be executed automatically by a hybrid PET/CT scanner or, if the PET and CT imaging sets have been acquired through different equipment, by a dedicated module of the radiotherapy treatment planning system. Both approaches have some disadvantages: in the first case, the bore of a PET/CT system generally used in clinical practice often does not allow the use of certain bulky devices for patient immobilization in radiotherapy, whereas in the second case the result could be affected by limitations in window/level visualization of two different image modalities, and the displayed PET volumes can appear not to be related to the actual uptake into the patient. To overcome these problems, at our centre a specific procedure has been studied and tested in 30 patients, allowing good results of precision in the target contouring to be obtained. The process consists of segmentation of the biological target volume by a dedicated PET/CT console and its export to a dedicated radiotherapy system, where an image registration between the CT images acquired by the PET/CT scanner and a large-bore CT is performed. The planning target volume is contoured only on the large-bore CT and is used for virtual simulation, to individuate permanent skin markers on the patient.

Dosimetric Evaluation of Intensity Modulated Radiotherapy and 4-Field 3-D Conformal Radiotherapy in Prostate Cancer Treatment

Directory of Open Access Journals (Sweden)

Bora Uysal

2013-03-01

Full Text Available Objective: The purpose of this dosimetric study is the targeted dose homogeneity and critical organ dose comparison of 7-field Intensity Modulated Radiotherapy (IMRT and 3-D 4-field conformal radiotherapy. Study Design: Cross sectional study. Material and Methods: Twenty patients with low and moderate risk prostate cancer treated at Gülhane Military Medical School Radiation Oncology Department between January 2009 and December 2009 are included in this study. Two seperate dosimetric plans both for 7-field IMRT and 3D-CRT have been generated for each patient to comparatively evaluate the dosimetric status of both techniques and all the patients received 7-field IMRT. Results: Dose-comparative evaluation of two techniques revealed the superiority of IMRT technique with statistically significantly lower femoral head doses along with reduced critical organ dose-volume parameters of bladder V60 (the volume receiving 60 Gy and rectal V40 (the volume receiving 40 Gy and V60. Conclusion: It can be concluded that IMRT is an effective definitive management tool for prostate cancer with improved critical organ sparing and excellent dose homogenization in target organs of prostate and seminal vesicles.

Target tailoring and proton beam therapy to reduce small bowel dose in cervical cancer radiotherapy. A comparison of benefits

International Nuclear Information System (INIS)

Boer, Peter de; Westerveld, Henrike; Smit, Mark; Bel, Arjan; Rasch, Coen R.N.; Stalpers, Lukas J.A.; Schoot, Agustinus J.A.J. van de; Buist, Marrije R.

2018-01-01

The aim of the study was to investigate the potential clinical benefit from both target tailoring by excluding the tumour-free proximal part of the uterus during image-guided adaptive radiotherapy (IGART) and improved dose conformity based on intensity-modulated proton therapy (IMPT). The study included planning CTs from 11 previously treated patients with cervical cancer with a >4-cm tumour-free part of the proximal uterus on diagnostic magnetic resonance imaging (MRI). IGART and robustly optimised IMPT plans were generated for both conventional target volumes and for MRI-based target tailoring (where the non-invaded proximal part of the uterus was excluded), yielding four treatment plans per patient. For each plan, the V 15Gy , V 30Gy , V 45Gy and D mean for bladder, sigmoid, rectum and bowel bag were compared, and the normal tissue complication probability (NTCP) for ≥grade 2 acute small bowel toxicity was calculated. Both IMPT and MRI-based target tailoring resulted in significant reductions in V 15Gy , V 30Gy , V 45Gy and D mean for bladder and small bowel. IMPT reduced the NTCP for small bowel toxicity from 25% to 18%; this was further reduced to 9% when combined with MRI-based target tailoring. In four of the 11 patients (36%), NTCP reductions of >10% were estimated by IMPT, and in six of the 11 patients (55%) when combined with MRI-based target tailoring. This >10% NTCP reduction was expected if the V 45Gy for bowel bag was >275 cm 3 and >200 cm 3 , respectively, during standard IGART alone. In patients with cervical cancer, both proton therapy and MRI-based target tailoring lead to a significant reduction in the dose to surrounding organs at risk and small bowel toxicity. (orig.) [de

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)

International Nuclear Information System (INIS)

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 20/30 , and mean dose of the left kidney, as well as the V 20/30 of the liver, compared with the 3D-CRT plans. And the sVMAT technique reduced the V 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

Radiotherapy in prostate cancer. Innovative techniques and current controversies

International Nuclear Information System (INIS)

Geinitz, Hans

2015-01-01

Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

Radiotherapy for cancer patients aged 85 or older

International Nuclear Information System (INIS)

Kan, Tomoko; Kodani, Kazuhiko; Michimoto, Koichi; Ogawa, Toshihide

2009-01-01

The purpose of this study was to investigate the clinical efficacy and problems of radiotherapy for cancer patients aged 85 or older. Fifty-three patients (26 men, 27 women) who underwent radiotherapy were analyzed retrospectively. Median age was 87 years (range; 85-99). Treatment policy was classified into curative, semi-curative (treatment field or total dose were limited due to performance status) and palliative therapy. Head-and-neck, bladder and skin cancer were the most common primary disease. The treatment was deemed curative in 27%, semi-curative in 13%, and palliative in 49%. Total dose of semi-curative therapy was almost same compared with curative therapy. The rate of treatment completion and effectiveness were not significantly different in curative therapy and semi-curative therapy. We should consider to reduce the field size to gross target volume, but to treat with substantial dose to make radiotherapy safe and effective. We must be aware that elderly patients have basically low tolerability. (author)

Guidelines for equipment and staffing of radiotherapy facilities in the European countries: Final results of the ESTRO-HERO survey

International Nuclear Information System (INIS)

Dunscombe, Peter; Grau, Cai; Defourny, Noémie; Malicki, Julian; Borras, Josep M.; Coffey, Mary; Bogusz, Marta; Gasparotto, Chiara; Slotman, Ben; Lievens, Yolande; Kokobobo, Arianit; Sedlmayer, Felix; Slobina, Elena; De Hertogh, Olivier; Hadjieva, Tatiana; Petera, Jiri; Eriksen, Jesper Grau; Jaal, Jana; Bly, Ritva; Azria, David

2014-01-01

Background and purpose: In planning to meet evidence based needs for radiotherapy, guidelines for the provision of capital and human resources are central if access, quality and safety are not to be compromised. A component of the ESTRO-HERO (Health Economics in Radiation Oncology) project is to document the current availability and content of guidelines for radiotherapy in Europe. Materials and methods: An 84 part questionnaire was distributed to the European countries through their national scientific and professional radiotherapy societies with 30 items relating to the availability of guidelines for equipment and staffing and selected operational issues. Twenty-nine countries provided full or partial evaluable responses. Results: The availability of guidelines across Europe is far from uniform. The metrics used for capital and human resources are variable. There seem to have been no major changes in the availability or specifics of guidelines over the ten-year period since the QUARTS study with the exception of the recent expansion of RTT staffing models. Where comparison is possible it appears that staffing for radiation oncologists, medical physicists and particularly RTTs tend to exceed guidelines suggesting developments in clinical radiotherapy are moving faster than guideline updating. Conclusion: The efficient provision of safe, high quality radiotherapy services would benefit from the availability of well-structured guidelines for capital and human resources, based on agreed upon metrics, which could be linked to detailed estimates of need

Final report of a randomized trial on altered-fractionated radiotherapy in nasopharyngeal carcinoma prematurely terminated by significant increase in neurologic complications

International Nuclear Information System (INIS)

Teo, Peter Man Lung; Leung, Sing Fai; Chan, Anthony Tak Cheung; Leung, Thomas Wai Tong; Choi, Peter Ho Keung; Kwan, Wing Hong; Lee, Wai Yee; Chau, Ricky Ming Chun; Yu, Peter Kau Wing; Johnson, Philip James

2000-01-01

Purpose: The aim of the present study was to compare the survival, local control and complications of conventional/accelerated-hyperfractionated radiotherapy and conventional radiotherapy in nonmetastatic nasopharyngeal carcinoma (NPC). Methods and Materials: From February 1993 to October 1995, 159 patients with newly diagnosed nonmetastatic (M0) NPC with N0 or 4 cm or less N1 disease (Ho's N-stage classification, 1978) were randomized to receive either conventional radiotherapy (Arm I, n = 82) or conventional/accelerated-hyperfractionated radiotherapy (Arm II, n = 77). Stratification was according to the T stage. The biologic effective dose (10 Grays) to the primary and the upper cervical lymphatics were 75.0 and 73.1 for Arm I and 84.4 and 77.2 for Arm II, respectively. Results: With comparable distribution among the T stages between the two arms, the free from local failure rate at 5 years after radiotherapy was not significantly different between the two arms (85.3%; 95% confidence interval, 77.2-93.4% for Arm I; and 88.9%; 95% confidence interval, 81.7-96.2% for Arm II). The two arms were also comparable in overall survival, relapse-free survival, and rates of distant metastasis and regional relapse. Conventional/accelerated-hyperfractionated radiotherapy was associated with significantly increased radiation-induced damage to the central nervous system (including temporal lobe, cranial nerves, optic nerve/chiasma, and brainstem/spinal cord) in Arm II. Although insignificant, radiation-induced cranial nerve(s) palsy (typically involving VIII-XII), trismus, neck soft tissue fibrosis, and hypopituiturism and hypothyroidism occurred more often in Arm II. In addition, the complications occurred at significantly shorter intervals after radiotherapy in Arm II. Conclusion: Accelerated hyperfractionation when used in conjunction with a two-dimensional radiotherapy planning technique, in this case the Ho's technique, resulted in increased radiation damage to the central

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

International Nuclear Information System (INIS)

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

2011-01-01

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 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.

Prostate image-guided radiotherapy by megavolt cone-beam CT

International Nuclear Information System (INIS)

Zucca, Sergio; Carau, Barbara; Solla, Ignazio; Garibaldi, Elisabetta; Farace, Paolo; Lay, Giancarlo; Meleddu, Gianfranco; Gabriele, Pietro

2011-01-01

To test megavolt cone-beam CT (MV-CBCT) in order to evaluate setup errors in prostate radiotherapy. The setup of 9 patients was verified weekly by electronic portal imaging (EPI) and MV-CBCT, both performed in the same treatment session. EPI were compared with digitally reconstructed radiographies (DRRs). MV-CBCTs were matched to simulation CTs by manual registration based on bone markers (BMR), by manual registration based on soft tissues (STR) - rectum, bladder, and seminal vesicles - and by automatic registration (AR) performed by a mutual information algorithm. Shifts were evaluated along the three main axes: anteroposterior (AP), craniocaudal (CC), and laterolateral (LL). Finally, in 4 additional patients showing intraprostatic calcifications, the calcification mismatch error was used to evaluate the three MV-CBCT matching methods. A total of 50 pairs of orthogonal EPIs and 50 MV-CBCTs were analyzed. Assuming an overall tolerance of 2 mm, no significant differences were observed comparing EPI vs BMR in any axis. A significant difference (p < 0.001) was observed along the AP axis comparing EPI vs AR and EPI vs STR. On the calcification data set (22 measures), the calcification mismatch along the AP direction was significantly lower (p < 0.05) after STR than after BMR or AR. Bone markers were not an effective surrogate of the target position and significant differences were observed comparing EPI or BMR vs STR, supporting the assessment of soft tissue position by MVCBs to verify and correct patient setup in prostate radiotherapy. (orig.)

Prostate image-guided radiotherapy by megavolt cone-beam CT

Energy Technology Data Exchange (ETDEWEB)

Zucca, Sergio; Carau, Barbara; Solla, Ignazio; Garibaldi, Elisabetta; Farace, Paolo; Lay, Giancarlo; Meleddu, Gianfranco; Gabriele, Pietro [Regional Oncological Hospital, Cagliari (Italy). Dept. of Radiooncology

2011-08-15

To test megavolt cone-beam CT (MV-CBCT) in order to evaluate setup errors in prostate radiotherapy. The setup of 9 patients was verified weekly by electronic portal imaging (EPI) and MV-CBCT, both performed in the same treatment session. EPI were compared with digitally reconstructed radiographies (DRRs). MV-CBCTs were matched to simulation CTs by manual registration based on bone markers (BMR), by manual registration based on soft tissues (STR) - rectum, bladder, and seminal vesicles - and by automatic registration (AR) performed by a mutual information algorithm. Shifts were evaluated along the three main axes: anteroposterior (AP), craniocaudal (CC), and laterolateral (LL). Finally, in 4 additional patients showing intraprostatic calcifications, the calcification mismatch error was used to evaluate the three MV-CBCT matching methods. A total of 50 pairs of orthogonal EPIs and 50 MV-CBCTs were analyzed. Assuming an overall tolerance of 2 mm, no significant differences were observed comparing EPI vs BMR in any axis. A significant difference (p < 0.001) was observed along the AP axis comparing EPI vs AR and EPI vs STR. On the calcification data set (22 measures), the calcification mismatch along the AP direction was significantly lower (p < 0.05) after STR than after BMR or AR. Bone markers were not an effective surrogate of the target position and significant differences were observed comparing EPI or BMR vs STR, supporting the assessment of soft tissue position by MVCBs to verify and correct patient setup in prostate radiotherapy. (orig.)

Patient positioning and immobilization in static and dynamic adaptive radiotherapy: an integral part of IGRT

International Nuclear Information System (INIS)

Oinam, Arun S.

2016-01-01

Radiotherapy treatment deals with different varieties of treatment procedures depending on type and stages of tumors. These treatments are grossly classified into palliative curative treatment. Immobilizations used in this treatment are designed with respect to this classification as well as the techniques. With the improvements in imaging technology used in Radiotherapy, patient position set up margin can be reduced as compared to the conventional radiotherapy. Still immobilization in patient position setup has been an integral part of Image Guided Radiotherapy (lGRT) and Stereotactic Radio Surgery (SRS) and Radiotherapy (SRT). Immobilization used in this technique should produce a minimum attenuation of radiation beam as well as positioning comfort and this will enhance the reproducibility for the daily position setup and immobilize the patient during the treatment. Advanced dose delivery technique like Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Radiotherapy (VMAT) can do differential dose sculpting around and inside the irregular shape different target volumes while minimizing the dose to the surrounding organs at risk. A small positional error may produce the mistreatment of target and exposure of organs at risk beyond the acceptable dose limits. Such a potential positional error can be reduced if different varieties of good immobilizing devices are properly utilized. The immobilization used in the treatment of Head and Neck and Cranial tumor can produce better immobilization as compared to abdominal and pelvic tumors which are forced to move by the inability to control movements of lung and heart as well as the very large flabby tissues which are attached skeleton bones

Radiotherapy

International Nuclear Information System (INIS)

Zedgenidze, G.A.; Kulikov, V.A.; Mardynskij, Yu.S.

1984-01-01

The technique for roentgenotopometric and medicamentous preparation of patients for radiotherapy has been reported in detail. The features of planning and performing of remote, intracavitary and combined therapy in urinary bladder cancer are considered. The more effective methods of radiotherapy have been proposed taking into account own experience as well as literature data. The comparative evaluation of treatment results and prognosis are given. Radiation pathomorphism of tumors and tissues of urinary bladder is considered in detail. The problems of diagnosis, prophylaxis and treatment of complications following radiodiagnosis and radiotherapy in patients with urinary bladder cancer are illustrated widely

Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation

Science.gov (United States)

Unkelbach, Jan; Menze, Bjoern H.; Konukoglu, Ender; Dittmann, Florian; Le, Matthieu; Ayache, Nicholas; Shih, Helen A.

2014-02-01

Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher-Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most

Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation

International Nuclear Information System (INIS)

Unkelbach, Jan; Dittmann, Florian; Le, Matthieu; Shih, Helen A; Menze, Bjoern H; Ayache, Nicholas; Konukoglu, Ender

2014-01-01

Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher–Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most

Emergence and present status of Lu-177 in targeted radiotherapy. The Indian scenario

Energy Technology Data Exchange (ETDEWEB)

Banerjee, S.; Das, T.; Chakraborty, S.; Venkatesh, M. [Bhabha Atomic Reseach Centre, Trombay, Mumbai (India). Radiopharmaceuticals Div.

2012-07-01

. In the present article, our research efforts toward standardization of production methodology of {sup 177}Lu in high specific activity and its utilization in the development of agents for targeted radiotherapy are being reported. (orig.)

Consensus Guidelines for Delineation of Clinical Target Volume for Intensity-Modulated Pelvic Radiotherapy for the Definitive Treatment of Cervix Cancer

International Nuclear Information System (INIS)

Lim, Karen; Small, William; Portelance, Lorraine; Creutzberg, Carien; Juergenliemk-Schulz, Ina M.; Mundt, Arno; Mell, Loren K.; Mayr, Nina; Viswanathan, Akila; Jhingran, Anuja; Erickson, Beth; De Los Santos, Jennifer; Gaffney, David; Yashar, Catheryn; Beriwal, Sushil; Wolfson, Aaron

2011-01-01

Purpose: Accurate target definition is vitally important for definitive treatment of cervix cancer with intensity-modulated radiotherapy (IMRT), yet a definition of clinical target volume (CTV) remains variable within the literature. The aim of this study was to develop a consensus CTV definition in preparation for a Phase 2 clinical trial being planned by the Radiation Therapy Oncology Group. Methods and Materials: A guidelines consensus working group meeting was convened in June 2008 for the purposes of developing target definition guidelines for IMRT for the intact cervix. A draft document of recommendations for CTV definition was created and used to aid in contouring a clinical case. The clinical case was then analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with kappa statistics as a measure of agreement between participants. Results: Nineteen experts in gynecological radiation oncology generated contours on axial magnetic resonance images of the pelvis. Substantial STAPLE agreement sensitivity and specificity values were seen for gross tumor volume (GTV) delineation (0.84 and 0.96, respectively) with a kappa statistic of 0.68 (p < 0.0001). Agreement for delineation of cervix, uterus, vagina, and parametria was moderate. Conclusions: This report provides guidelines for CTV definition in the definitive cervix cancer setting for the purposes of IMRT, building on previously published guidelines for IMRT in the postoperative setting.

Radiotherapy-induced emesis. An overview

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Feyer, P.; Buchali, A.; Hinkelbein, M.; Budach, V. [Department Radiotherapy, Humboldt-University Berlin (Germany); Zimmermann, J.S. [Department Radiotherapy, Christian Albrechts-University Kiel (Germany); Titlbach, O.J. [Department of Medicine I, Hospital Friedrichshain, Berlin (Germany)

1998-11-01

Background: A significant number of patients receiving radiotherapy experience the distressing side effects of emesis and nausea. These symptoms are some of the most distressing problems for the patients influencing their quality of life. Methods: International study results concerning radiotherapy-induced emesis are demonstrated. A German multicenter questionnaire examining the strategies to prevent or to treat radiotherapy-induced nausea and emesis is presented. An international analysis concerning incidence of emesis and nausea in fractionated radiotherapy patients is discussed. Finally the consensus of the consensus conference on antiemetic therapy from the Perugia International Cancer Conference V is introduced. Results: Untreated emesis can lead to complications like electrolyte disorders, dehydration, metabolic disturbances and nutrition problems with weight loss. Prophylactic antiemetics are often given to patients receiving single high-dose radiotherapy to the abdomen. A survey has revealed that antiemetic prophylaxis is not routinely offered to the patients receiving fractionated radiotherapy. However, there is a need for an effective treatment of emesis for use in this group of patients, too. In 20% of patients nausea and emesis can cause a treatment interruption because of an inadequate control of symptoms. Like in chemotherapy strategies there exist high, moderate, and low emetogenic treatment regimens in radiotherapy as well. The most emetogenic potential has the total body irradiation followed by radiotherapy to the abdomen. Radiotherapy induced emesis can be treated effectively with conventional antiemetics up to 50%. Conclusions: Studies with total body irradiation, fractionated treatment and high-dose single exposures have cleary demonstrated the value of 5-HT3-receptor antagonist antiemetics. There is a response between 60 and 97%. There is no difference in the efficacy of the different 5-HT3-antagonists. High-risk patients should be prophylactic

Results of patient specific quality assurance for patients undergoing stereotactic ablative radiotherapy for lung lesions

International Nuclear Information System (INIS)

Hardcastle, Nicholas; Clements, Natalie; Cramb, Jim; Wanigaratne, Derrick M.; Chesson, Brent; Aarons, Yolanda; Siva, Shankar; Ball, David; Kron, Tomas

2014-01-01

Hypofractionated image guided radiotherapy of extracranial targets has become increasingly popular as a treatment modality for inoperable patients with one or more small lesions, often referred to as stereotactic ablative body radiotherapy (SABR). This report details the results of the physical quality assurance (QA) program used for the first 33 lung cancer SABR radiotherapy 3D conformal treatment plans in our centre. SABR involves one or few fractions of high radiation dose delivered in many small fields or arcs with tight margins to mobile targets often delivered through heterogeneous media with non-coplanar beams. We have conducted patient-specific QA similar to the more common intensity modulated radiotherapy QA with particular reference to motion management. Individual patient QA was performed in a Perspex phantom using point dose verification with an ionisation chamber and radiochromic film for verification of the dose distribution both with static and moving detectors to verify motion management strategies. While individual beams could vary by up to 7 %, the total dose in the target was found to be within ±2 % of the prescribed dose for all 33 plans. Film measurements showed qualitative and quantitative agreement between planned and measured isodose line shapes and dimensions. The QA process highlighted the need to account for couch transmission and demonstrated that the ITV construction was appropriate for the treatment technique used. QA is essential for complex radiotherapy deliveries such as SABR. We found individual patient QA helpful in setting up the technique and understanding potential weaknesses in SABR workflow, thus providing confidence in SABR delivery.

Planning Target Margin Calculations for Prostate Radiotherapy Based on Intrafraction and Interfraction Motion Using Four Localization Methods

International Nuclear Information System (INIS)

Beltran, Chris; Herman, Michael G.; Davis, Brian J.

2008-01-01

Purpose: To determine planning target volume (PTV) margins for prostate radiotherapy based on the internal margin (IM) (intrafractional motion) and the setup margin (SM) (interfractional motion) for four daily localization methods: skin marks (tattoo), pelvic bony anatomy (bone), intraprostatic gold seeds using a 5-mm action threshold, and using no threshold. Methods and Materials: Forty prostate cancer patients were treated with external radiotherapy according to an online localization protocol using four intraprostatic gold seeds and electronic portal images (EPIs). Daily localization and treatment EPIs were obtained. These data allowed inter- and intrafractional analysis of prostate motion. The SM for the four daily localization methods and the IM were determined. Results: A total of 1532 fractions were analyzed. Tattoo localization requires a SM of 6.8 mm left-right (LR), 7.2 mm inferior-superior (IS), and 9.8 mm anterior-posterior (AP). Bone localization requires 3.1, 8.9, and 10.7 mm, respectively. The 5-mm threshold localization requires 4.0, 3.9, and 3.7 mm. No threshold localization requires 3.4, 3.2, and 3.2 mm. The intrafractional prostate motion requires an IM of 2.4 mm LR, 3.4 mm IS and AP. The PTV margin using the 5-mm threshold, including interobserver uncertainty, IM, and SM, is 4.8 mm LR, 5.4 mm IS, and 5.2 mm AP. Conclusions: Localization based on EPI with implanted gold seeds allows a large PTV margin reduction when compared with tattoo localization. Except for the LR direction, bony anatomy localization does not decrease the margins compared with tattoo localization. Intrafractional prostate motion is a limiting factor on margin reduction

SU-F-T-644: Reproducibility of Target Position Using Moderate Voluntary Breath- Hold During Liver Stereotactic Ablative Radiotherapy

International Nuclear Information System (INIS)

Cui, G; Trakul, N; Chang, E; Shiu, A

2016-01-01

Purpose: To evaluate the reproducibility of target position using moderate voluntary breath-hold during liver stereotactic ablative radiotherapy (SABR). Methods: Two patients who underwent liver SABR on a Varian TrueBeam STx linac were used for this study. Fiducial markers were placed in and around the target in the liver as surrogates for the target position and motion. GTVs were contoured by assessing tumor extent on contrast enhanced CT. The PTV was created from the GTV by adding 2 mm margins to account for the residual motion during breath-holds. A portable biofeedback system was used to facilitate the breath-hold to a reproducible position. The Varian RPM system was used for gating the linac. Proceeding each treatment, orthogonal kV pairs were taken, and alignment to nearby bony anatomy was performed. Then the breath-hold CBCT was acquired to align the fiducial markers. On-line fluoroscopy was used to fine-tune the breath-hold gating thresholds to correlate with the positions of the fiducial markers. The inter-fraction reproducibility of the target was evaluated by the offsets of the daily breath-hold CBCTs from the paired kV matches as a direct measure of the target position relative to the bony anatomy. The intra-fraction reproducibility of the target position was assessed by the gated window of the RPM marker block for each fraction. Results: The absolute mean offsets between the CBCT and paired kV matches in the vertical, longitudinal, and lateral directions were 0.06 cm, 0.10 cm, and 0.06 cm for patient 1, and 0.37 cm, 0.62 cm, and 0.09 cm for patient 2. The gated window of the RPM marker block for the breath-hold for each fraction was within 0.63 ± 0.16 cm and 0.59 ± 0.12 cm for patients 1 and 2, respectively. Conclusion: Moderate voluntary breath-hold showed good inter- and intra-fraction reproducibility of target position during liver SABR.

SU-F-T-644: Reproducibility of Target Position Using Moderate Voluntary Breath- Hold During Liver Stereotactic Ablative Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Cui, G; Trakul, N; Chang, E; Shiu, A [University Southern California, Los Angeles, CA (United States)

2016-06-15

Purpose: To evaluate the reproducibility of target position using moderate voluntary breath-hold during liver stereotactic ablative radiotherapy (SABR). Methods: Two patients who underwent liver SABR on a Varian TrueBeam STx linac were used for this study. Fiducial markers were placed in and around the target in the liver as surrogates for the target position and motion. GTVs were contoured by assessing tumor extent on contrast enhanced CT. The PTV was created from the GTV by adding 2 mm margins to account for the residual motion during breath-holds. A portable biofeedback system was used to facilitate the breath-hold to a reproducible position. The Varian RPM system was used for gating the linac. Proceeding each treatment, orthogonal kV pairs were taken, and alignment to nearby bony anatomy was performed. Then the breath-hold CBCT was acquired to align the fiducial markers. On-line fluoroscopy was used to fine-tune the breath-hold gating thresholds to correlate with the positions of the fiducial markers. The inter-fraction reproducibility of the target was evaluated by the offsets of the daily breath-hold CBCTs from the paired kV matches as a direct measure of the target position relative to the bony anatomy. The intra-fraction reproducibility of the target position was assessed by the gated window of the RPM marker block for each fraction. Results: The absolute mean offsets between the CBCT and paired kV matches in the vertical, longitudinal, and lateral directions were 0.06 cm, 0.10 cm, and 0.06 cm for patient 1, and 0.37 cm, 0.62 cm, and 0.09 cm for patient 2. The gated window of the RPM marker block for the breath-hold for each fraction was within 0.63 ± 0.16 cm and 0.59 ± 0.12 cm for patients 1 and 2, respectively. Conclusion: Moderate voluntary breath-hold showed good inter- and intra-fraction reproducibility of target position during liver SABR.

Transverse tomography and radiotherapy

International Nuclear Information System (INIS)

Leer, J.W.H.

1982-01-01

This study was intended to delineate the indications for radiotherapy treatment-planning with the help of computerized axial tomography (C.T.) and transverse analog tomography (T.A.T.). Radiotherapy localisation procedures with the conventional method (simulator), with the CT-scanner and with the transverse analog tomograph (T.A.T., Simtomix, Oldelft) were compared. As criterium for evaluation differences in reconstruction drawing based on these methods were used. A certain method was judged ''superior'' to another if the delineation of the target volume was more accurate, if a better impression was gained of the site of (for irradiation) organs at risk, or if the localisation could only be performed with that method. The selected group of patients consisted of 120 patients for whom a reconstruction drawing in the transverse plane was made according to the treatment philosophy. In this group CT-assisted localisation was judged on 68 occasions superior to the conventional method. In a number of cases it was found that a ''standard'' change in a standard target volume, on the base of augmented anatomical knowledge, made the conventional method sufficient. The use of CT-scanner for treatment planning was estimated. For ca. 270/1000 new patients a CT-scan is helpful (diagnostic scan), for 140 of them the scan is necessary (planning scan). The quality of the anatomical information obtained with the T.A.T. does not yet fall within acceptable limits, but progress has been made. (Auth.)

A New Cancer Radiotherapy System Using Multi Robotic Manipulators

International Nuclear Information System (INIS)

Kim, Seung Ho; Lee, Nam Ho; Lee, Byung Chul; Jeung, Kyung Min; Lee, Seong Uk; Bae, Yeong Geol; Na, Hyun Seok

2013-01-01

The CyberKnife system is state-of-the-art cancer treatment equipment that combines an image tracking technique, artificial intelligence software, robot technology, accelerator technology, and treatment simulation technology. The current CyberKnife System has significant shortcomings. The biggest problem is that it takes a longer time to treat a tumor. A long treatment time gives stress to patients. Furthermore it makes the patients uncomfortable with radiation and thus it is difficult to measure the exact radiation dose rate to the tumor in the processing. Linear accelerators for radiation treatment are dependent on imports, and demand high maintenance cost. This also makes the treatment cost higher and prevents the popularization of radiation. To solve the disadvantages of the existing CyberKnife, a radiation treatment robot system applied to several articulated robots is suggested. Essential element techniques for new radiotherapy robot system are investigated and some problems of similar existing systems are analyzed. This paper presents a general configuration of a new radiation robot treatment system including with a quantitative goal of the requirement techniques. This paper described a new radiotherapy robot system to track the tumor using multiple articulated robots in real time. The existing CyberKnife system using a single robot arm has disadvantages of a long radiotherapy time, high medical fee, and inaccurate measurement of the radiotherapy dose. So a new radiotherapy robot system for tumors has been proposed to solve the above problems of conventional CyberKnife systems. Necessary technologies to configure new the radiotherapy robot system have been identified. Quantitative targets of each technology have been established. Multiple robot arms are adopted to decrease the radiotherapy time. The results of this research are provided as a requisite technology for a domestic radiotherapy system and are expected to be the foundation of new technology. The

A New Cancer Radiotherapy System Using Multi Robotic Manipulators

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Ho; Lee, Nam Ho; Lee, Byung Chul; Jeung, Kyung Min; Lee, Seong Uk; Bae, Yeong Geol; Na, Hyun Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

The CyberKnife system is state-of-the-art cancer treatment equipment that combines an image tracking technique, artificial intelligence software, robot technology, accelerator technology, and treatment simulation technology. The current CyberKnife System has significant shortcomings. The biggest problem is that it takes a longer time to treat a tumor. A long treatment time gives stress to patients. Furthermore it makes the patients uncomfortable with radiation and thus it is difficult to measure the exact radiation dose rate to the tumor in the processing. Linear accelerators for radiation treatment are dependent on imports, and demand high maintenance cost. This also makes the treatment cost higher and prevents the popularization of radiation. To solve the disadvantages of the existing CyberKnife, a radiation treatment robot system applied to several articulated robots is suggested. Essential element techniques for new radiotherapy robot system are investigated and some problems of similar existing systems are analyzed. This paper presents a general configuration of a new radiation robot treatment system including with a quantitative goal of the requirement techniques. This paper described a new radiotherapy robot system to track the tumor using multiple articulated robots in real time. The existing CyberKnife system using a single robot arm has disadvantages of a long radiotherapy time, high medical fee, and inaccurate measurement of the radiotherapy dose. So a new radiotherapy robot system for tumors has been proposed to solve the above problems of conventional CyberKnife systems. Necessary technologies to configure new the radiotherapy robot system have been identified. Quantitative targets of each technology have been established. Multiple robot arms are adopted to decrease the radiotherapy time. The results of this research are provided as a requisite technology for a domestic radiotherapy system and are expected to be the foundation of new technology. The

Proposal for development of a system for planning radiotherapy of gliomas

International Nuclear Information System (INIS)

Caldeira, Alexandre D.

2015-01-01

In the last three years, discussions were held on several topics in Nuclear Medicine area, starting with the nuclear data processing, passing by deterministic and stochastic mathematical methods, and finalizing with computer simulations of the following phenomena: neutron transport, applied to boron neutron capture therapy, and neutron diffusion, to study growth of tumor cells. From a mathematical model applied to radiotherapy of gliomas available in literature, it is proposed a strategy for development of a computer system to assist the planning radiotherapy of gliomas. (author)

National arrangements for radiotherapy

International Nuclear Information System (INIS)

2007-01-01

After a presentation of several letters exchanged between the French health ministry and public agencies in charge of public health or nuclear safety after a radiotherapy accident in Epinal, this report comments the evolution of needs in cancerology care and the place given to radiotherapy. It outlines the technological and organisational evolution of radiotherapy and presents the distribution of radiotherapy equipment, of radio-therapists and other radiotherapy professionals in France. Within the context of radiotherapy accidents which occurred in 2007, it presents the regulatory arrangements which aimed at improving the safety, short term and middle term arrangements which are needed to support and structure radiotherapy practice quality. It stresses the fact that the system will deeply evolve by implementing a radiotherapy vigilance arrangement and a permanent follow-on and adaptation plan based on surveys and the creation of a national committee

Whither radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Ross, W M

1987-03-01

The 1986 Glyn Evans Memorial Lecture, given at the Joint Provincial Meeting of the Royal College of Radiologists, Sheffield, September 1986, sketches an outline of the history of radiotherapy and discusses the future development of the art. Topics included are siting of centres, training needs, the relationship of radiotherapy to other medical specialities, and the advantages and disadvantages of radiotherapy practitioners forming a separate medical College. (U.K.)

Radiotherapy skin care: A survey of practice in the UK

International Nuclear Information System (INIS)

Harris, Rachel; Probst, Heidi; Beardmore, Charlotte; James, Sarah; Dumbleton, Claire; Bolderston, Amanda; Faithfull, Sara; Wells, Mary; Southgate, Elizabeth

2012-01-01

Aim: The primary objective of the survey was to evaluate clinical skin care practice in radiotherapy departments across the United Kingdom. Methods and sample: A questionnaire containing sixty-one questions grouped into eight themed sections was developed and a link to an on-line survey, using the Survey Monkey™ tool, was e-mailed to all radiotherapy department managers in the United Kingdom (N = 67). Each recipient was invited to provide one response per department. Key results: Fifty-four departments responded within the allocated timeframe giving a final response rate of 81%. Products and their use for skin conditions varied and some outdated and unfounded practices were still being used which did not always reflect the current evidence base. The amount of data routinely collected on skin toxicity was limited making it difficult to quantify the extent of skin morbidity following radiotherapy. Conclusion: The survey demonstrated variability in skin care practice in radiotherapy departments across the UK, with limited practice based on evidence or on skin toxicity measurement and monitoring.

Radiotherapy in bladder cancer

International Nuclear Information System (INIS)

Rozan, R.

1992-01-01

In 1992, the problem of the vesical radiotherapy is not resolved. The author presents the situation and the different techniques of radiotherapy in bladder cancers: external radiotherapy, only and associated with surgery, interstitial curietherapy and non-classical techniques as per operative radiotherapy, neutron therapy and concurrent radiotherapy with chemotherapy. In order to compare their efficiency, the five-year survival are given in all cases.(10 tabs)

A technique of using gated-CT images to determine internal target volume (ITV) for fractionated stereotactic lung radiotherapy

International Nuclear Information System (INIS)

Jin Jianyue; Ajlouni, Munther; Chen Qing; Yin, Fang-Fang; Movsas, Benjamin

2006-01-01

Background and purpose: To develop and evaluate a technique and procedure of using gated-CT images in combination with PET image to determine the internal target volume (ITV), which could reduce the planning target volume (PTV) with adequate target coverage. Patients and methods: A skin marker-based gating system connected to a regular single slice CT scanner was used for this study. A motion phantom with adjustable motion amplitude was used to evaluate the CT gating system. Specifically, objects of various sizes/shapes, considered as virtual tumors, were placed on the phantom to evaluate the number of phases of gated images required to determine the ITV while taking into account tumor size, shape and motion. A procedure of using gated-CT and PET images to define ITV for patients was developed and was tested in patients enrolled in an IRB approved protocol. Results: The CT gating system was capable of removing motion artifacts for target motion as large as 3-cm when it was gated at optimal phases. A phantom study showed that two gated-CT scans at the end of expiration and the end of inspiration would be sufficient to determine the ITV for tumor motion less than 1-cm, and another mid-phase scan would be required for tumors with 2-cm motion, especially for small tumors. For patients, the ITV encompassing visible tumors in all sets of gated-CT and regular spiral CT images seemed to be consistent with the target volume determined from PET images. PTV expanded from the ITV with a setup uncertainty margin had less volume than PTVs from spiral CT images with a 10-mm generalized margin or an individualized margin determined at fluoroscopy. Conclusions: A technique of determining the ITV using gated-CT images was developed and was clinically implemented successfully for fractionated stereotactic lung radiotherapy

Experiment study with baculovirus-mediated transfer of the thyroid sodium/iodide symporter gene into thyroid cancer for a targeted radiotherapy

International Nuclear Information System (INIS)

Zhang Yifan; Li Biao; Zhao Long; You Bei; Yin Guizhi; Zhu Chengmo

2004-01-01

Objective: To explore the feasibility of thyroid cancers for radiotherapy by using baculoviral vector to deliver the NIS gene into the tumor cells. Method: Constructed a recombinant baculovirus encoding the human NIS gene under the control of the cytomegalovirus promoter. Using a mouse monoclonal antibody and a FITC-labeled antimouse antibody to confirm expression of the NIS protein of infected tumor cells by immunofluorescence. In vitro iodide uptake experiments were carded out on BacNIS-infected tumor cells to further characterize the BacNIS virus, and cell killing with 131I and clonogenic assay were performed on BacNIS-infected cell to observe the selective killing effect of 1311 on NIS-expressing cells. Results: Infection of thyroidcancer cells (FTC-133, W3) with BacNIS resulted in perchlorate-sensitive 125I uptake by these cells to a higher level than that in noninfected cells. But 1251 uptake of 8505C is very low. Demonstrating that the BacNIS vector can function in tumor cells. In addition, AdNIS-infected tumor cells were selectively killed by exposure to 1311, as revealed by clonogenicassays, higher than that in nontreated tumors. Conclusions: AdNIS is very efficient in triggering iodide uptake by infected tumor cell, outlining the potential of this novel cancer gene therapy approach for a targeted radiotherapy. (authors)

4D-CT-based target volume definition in stereotactic radiotherapy of lung tumours: Comparison with a conventional technique using individual margins

International Nuclear Information System (INIS)

Hof, Holger; Rhein, Bernhard; Haering, Peter; Kopp-Schneider, Annette; Debus, Juergen; Herfarth, Klaus

2009-01-01

Purpose: To investigate the dosimetric benefit of integration of 4D-CT in the planning target volume (PTV) definition process compared to conventional PTV definition using individual margins in stereotactic body radiotherapy (SBRT) of lung tumours. Material and methods: Two different PTVs were defined: PTV conv consisting of the helical-CT-based clinical target volume (CTV) enlarged isotropically for each spatial direction by the individually measured amount of motion in the 4D-CT, and PTV 4D encompassing the CTVs defined in the 4D-CT phases displaying the extremes of the tumour position. Tumour motion as well as volumetric and dosimetric differences and relations of both PTVs were evaluated. Results: Volumetric examinations revealed a significant reduction of the mean PTV by 4D-CT from 57.7 to 40.7 cm 3 (31%) (p 4D in PTV conv (r = -0.69, 90% confidence limits: -0.87 and -0.34, p = 0.007). Mean lung dose (MLD) was decreased significantly by 17% (p < 0.001). Conclusions: In SBRT of lung tumours the mere use of individual margins for target volume definition cannot compensate for the additional effects that the implementation of 4D-CT phases can offer.

Experimental radiotherapy and clinical radiobiology. Vol. 19. Proceedings; Experimentelle Strahlentherapie und Klinische Strahlenbiologie. Bd. 19. Proceedings

Energy Technology Data Exchange (ETDEWEB)

Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemann, H Peter; Zips, Daniel [eds.

2010-12-18

The proceedings include review contributions on radio-oncology, and new radiation technologies and molecular prediction; and poster sessions on the following topics: hypoxia; molecular mechanisms of radiation resistance; molecular targeting; DNA repair; biological imaging; biology of experimental radiations; normal tissue toxicity; modern radiotherapy; tumor hypoxia and metabolic micro milieu; immune system and radiotherapy.

Brainstem tolerance to conformal radiotherapy of skull base tumors

International Nuclear Information System (INIS)

Debus, J.; Hug, E.B.; Munzenrider, J.E.; Liebsch, N.J.; O'Farrell, D.; Efird, J.; Daly, W.; Suit, H.D.

1996-01-01

Purpose/Objective: Brainstem tolerance to inhomogenous radiation doses applied by modern conformal radiotherapy has not yet been examined. The aim of this study was to analyse the incidence of brainstem toxicity in patients treated for skull base tumors with high dose conformal radiotherapy. Materials and Methods: Between 1974 and 1995, 367 patients with chordomas (n=195) and chondrosarcomas (n=172) of the base of skull have been treated with combined megavoltage photon and 160 MeV proton radiotherapy. All patients had previously undergone biopsy, subtotal or total tumor removal. 104 patients had two or more surgical procedures before radiotherapy. Following 3D treatment planning with delineation of target volumes and critical non-target structures, dose distributions and dose volume histograms were calculated [at the time of treatment delivery]. Radiotherapy was given once a day, 1.8 Gy or CGE (Cobalt Gy Equivalent: Proton Gy X 1.1) per fraction, 5 fractions per week, with prescribed target doses ranging from 63 CGE to 79.2 CGE (mean = 67.8 CGE). Doses to the brainstem surface were limited to ≤64 CGE and to the brainstem center to ≤53 CGE. Dose distributions were developed to limit dose to brainstem surface and center; current plans limit dose to surface and center to ≤64 CGE and ≤53 CGE, respectively. Brainstem toxicity was scored according to the RTOG grading system. Results: Follow-up ranged from 6 months to 21.4 years (mean = 42.5 months). Brainstem symptoms, attributable to the treatment, developed in 17 of 282 patients with local tumor control (6.0%), resulting in death of three patients. The mean time to onset of symptoms was 17 months (range: 4.5 to 177 months). These symptoms appeared in 89.5% within 3 years. Grading of the brainstem toxicity is listed in table 1. Actuarial rates of 5 and 10 year toxicity free survival were 87% and 82% respectively. Increased risk of brainstem toxicity was significantly associated with maximum brainstem dose

The study of target delineation and target movement of whole breast assisted by active breathing control in intensity modulated radiotherapy after breast conservative surgery

International Nuclear Information System (INIS)

Li Jianbing; Yu Jinming; Ma Zhifang; Lu Jie; Sun Tao; Guo Shoufang; Wang Jingguo

2009-01-01

Objective: To explore the influence of different delineators and different delineating time on target determination of the whole breast and to explore intrafraction and interfraction target displacements of the breast on moderate deep inspiration breathing hold (mDIBH) assisted by active breathing control (ABC) alter breast conservative surgery. Methods: Twenty patients received primary CT-simulation assisted by ABC to get five sets of CT image on the three breathing condition which included one set from free breath (FB), two sets from mDIBH and two sets from deep expiration breathing control (DEBH). After radiotherapy with ten to fifteen fractions, the repeat CT-simulation was carried out to get the same five sets of CT image as the primary CT- simulation. The whole breast target were delineated at different time by the same delineator and delineated respectively by five delineators on the first set of CT images got with mDIBH from the primary CT-simulation, and to compare the influence of delineator and delineating time on the whole breast target. The total silver clips in the cavity were marked respectively on the two sets of CT images got with mDIBH from the primary CT-simulation, and to compare the intrafraction displacement of geometric body structured by the total of silver clips. The two ribs near the isocentric plane of the breast target were delineated respectively on two sets of the mDIBH CT image from the primary CT-simulation and on one set of the mDIBH CT image from the repeat CT-simulation, and comparing the movement of the point of interest (POI) of the ribs delineated to get the value of intrafraction and interfraction thoracic expansion. Results: There was not statistically significant between the four volumes of whole breast targets delineated by the same delineator at different time, but with statistics significant between the volumes of whole breast target delineated by the different delineators ( F=19.681, P=0.000). There was not statistically

National arrangements for radiotherapy; Mesures nationales pour la radiotherapie. Travail collectif des missions

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

After a presentation of several letters exchanged between the French health ministry and public agencies in charge of public health or nuclear safety after a radiotherapy accident in Epinal, this report comments the evolution of needs in cancerology care and the place given to radiotherapy. It outlines the technological and organisational evolution of radiotherapy and presents the distribution of radiotherapy equipment, of radio-therapists and other radiotherapy professionals in France. Within the context of radiotherapy accidents which occurred in 2007, it presents the regulatory arrangements which aimed at improving the safety, short term and middle term arrangements which are needed to support and structure radiotherapy practice quality. It stresses the fact that the system will deeply evolve by implementing a radiotherapy vigilance arrangement and a permanent follow-on and adaptation plan based on surveys and the creation of a national committee.

Development of new microencapsulated beta emitters for internal radiotherapy

International Nuclear Information System (INIS)

Perdrisot, R.; Monteil, J.; Le Jeune, J.J.; Pouliquen, D.; Jallet, P.; Beau, P.; Lepape, A.

1993-01-01

We have developed new microencapsulated beta emitter radiotracers which could be used in nuclear medicine for selective internal radiotherapy. Their efficacy was evaluated on B16 melanoma tumor model in mice, using phosphorus 31 spectroscopy. This kind of tracer would allow a precise targetting of beta irradiation

Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors

International Nuclear Information System (INIS)

Caudrelier, J.M.; Auliard, A.; Sarrazin, T.; Gibon, D.; Coche-Dequeant, B.; Castelain, B.

2001-01-01

Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors. Purpose. - We prospectively compared a conventional treatment planning (PT2D) and 3-dimensional conformal treatment planning (PT3D) for radiotherapy of cerebral tumours. Patients and methods.- Patients treated between 1/10/98 and 1/4/99 by irradiation for cerebral tumours were analysed. For each case, we planned PT2D using conventional orthogonal x-ray films, and afterward, PT3D using CT scan. Gross tumor volume, planning target volume and normal tissue volumes were defined. Dose was prescribed according to report 50 of the International Commission on Radiation Units and Measurements (ICRU). We compared surfaces of sagittal view targets defined on PT2D and PT3D and called them S2D and S3D, respectively. Irradiated volumes by 90% isodoses (VE-90%) and normal tissue volumes irradiated by 20, 50, 90% isodoses were calculated and compared using Student's paired t-test. Results. -There was a concordance of 84% of target surfaces defined on PT2D and PT3D. Percentages of target surface under- or-over defined by PT2D were 16 and 13% respectively. VE-90% was decreased by 15% (p = 0.07) with PT3D. Normal brain volume irradiated by 90% isodose was decreased by 27% with PT3D (p = 0.04). Conclusion.- For radiotherapy of cerebral tumors using only coplanar beams, PT3D leads to a reduction of normal brain tissue irradiated. We recommend PT3D for radiotherapy of cerebral tumors, particularly for low-grade or benign tumors (meningiomas, neuromas, etc.). (authors)

To understand radiotherapy

International Nuclear Information System (INIS)

2009-01-01

Dealing with the use of radiotherapy for adults, this guide indicates when a radiotherapy is suggested, how it acts, how the treatment is chosen, which are the professionals involved. It describes how an external radiotherapy takes place and its various techniques, the different types of side effects (general, specific to the treated zone, late effects). It indicates which organs can be treated by curie-therapy, the different curie-therapy treatment modalities, how a curie-therapy takes place and which are its side effects. It outlines how to better cope with radiotherapy (how to be supported, the important role of relatives, everyday life questions, rights). It indicates and comments the different measures adopted for the safety and quality of radiotherapy

Targeting the NFκB signaling pathways for breast cancer prevention and therapy.

Science.gov (United States)

Wang, Wei; Nag, Subhasree A; Zhang, Ruiwen

2015-01-01

The activation of nuclear factor-kappaB (NFκB), a proinflammatory transcription factor, is a commonly observed phenomenon in breast cancer. It facilitates the development of a hormone-independent, invasive, high-grade, and late-stage tumor phenotype. Moreover, the commonly used cancer chemotherapy and radiotherapy approaches activate NFκB, leading to the development of invasive breast cancers that show resistance to chemotherapy, radiotherapy, and endocrine therapy. Inhibition of NFκB results in an increase in the sensitivity of cancer cells to the apoptotic effects of chemotherapeutic agents and radiation and restoring hormone sensitivity, which is correlated with increased disease-free survival in patients with breast cancer. In this review article, we focus on the role of the NFκB signaling pathways in the development and progression of breast cancer and the validity of NFκB as a potential target for breast cancer prevention and therapy. We also discuss the recent findings that NFκB may have tumor suppressing activity in certain cancer types. Finally, this review also covers the state-of-the-art development of NFκB inhibitors for cancer therapy and prevention, the challenges in targeting validation, and pharmacology and toxicology evaluations of these agents from the bench to the bedside.

Role of radiotherapy in the treatment of meningiomas; Role de la radiotherapie dans le traitement des meningiomes cerebraux

Energy Technology Data Exchange (ETDEWEB)

Noel, G. [Centre de protontherapie, 91 - Orsay (France); Renard, A.; Mazeron, J.J. [Groupe Hospitalier la Pitie-Salpetriere, Service de Radiotherapie, AP-HP, 75 - Paris (France); Valery, C. [Groupe Hospitalier la Pitie-Salpetriere, Service de Neurochirurgie, AP-HP, 75 - Paris (France); Mokhtari, K. [Groupe Hospitalier la Pitie-Salpetriere, Lab. de Neuropathologie Raymond-Escourolle, AP-HP, 75 - Paris (France)

2001-06-01

Role of radiotherapy in the treatment of meningiomas. Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively. (authors)

The incidence of inclusion of the sigmoid colon and small bowel in the planning target volume in radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Meerleer, G.O. de; Vakaet, L.; Neve, W.J. de; Villeirs, G.M.; Delrue, L.J.

2004-01-01

Background and purpose: in radiotherapy for prostate cancer, the rectum is considered the dose-limiting organ. The incidence of overlap between the sigmoid colon and/or small bowel and the planning target volume (PTV) as well as the dose to sigmoid colon and small bowel were investigated. Patients and methods: the CT data of 75 prostate cancer patients were analyzed. The clinical target volume (CTV) consisted of prostate and seminal vesicles. The PTV was defined as a three-dimensional expansion of the CTV with a 10-mm margin in craniocaudal and a 7-mm margin in the other directions. All patients were planned to a mean CTV dose of at least 76 Gy. Minimum CTV dose was set at 70 Gy. Dose inhomogeneity within the CTV was kept between 12% and 17%. Sigmoid colon was defined upward from the level where the rectum turned in a transverse plane. Contrast-filled small bowel was contoured on all slices where it was visible. The presence of sigmoid colon and/or small bowel in close vicinity to or overlapping with the PTV was recorded. For each case, the dose to the sigmoid colon and small bowel was calculated. Results: the PTV was found to overlap with the sigmoid colon in 60% and with the small bowel in 19% of the cases. In these patients, mean maximum dose to the sigmoid colon was 76.2 Gy (5th-95th percentile: 70.0-80.7 Gy). Mean maximum dose to the small bowel was 74.9 Gy (5th-95th percentile: 68.0-80.0 Gy). Conclusion: when systematically investigating the anatomic position of sigmoid colon and small bowel in patients accepted for prostate irradiation, parts of both organs were often observed in close vicinity to the PTV. Apart from the rectum, these organs may be dose-limiting in prostate radiotherapy. (orig.)

The incidence of inclusion of the sigmoid colon and small bowel in the planning target volume in radiotherapy for prostate cancer

Energy Technology Data Exchange (ETDEWEB)

Meerleer, G.O. de; Vakaet, L.; Neve, W.J. de [Dept. of Radiation Oncology, Gent Univ. Hospital, Gent (Belgium); Villeirs, G.M.; Delrue, L.J. [Dept. of Radiology, Gent Univ. Hospital, Gent (Belgium)

2004-09-01

Background and purpose: in radiotherapy for prostate cancer, the rectum is considered the dose-limiting organ. The incidence of overlap between the sigmoid colon and/or small bowel and the planning target volume (PTV) as well as the dose to sigmoid colon and small bowel were investigated. Patients and methods: the CT data of 75 prostate cancer patients were analyzed. The clinical target volume (CTV) consisted of prostate and seminal vesicles. The PTV was defined as a three-dimensional expansion of the CTV with a 10-mm margin in craniocaudal and a 7-mm margin in the other directions. All patients were planned to a mean CTV dose of at least 76 Gy. Minimum CTV dose was set at 70 Gy. Dose inhomogeneity within the CTV was kept between 12% and 17%. Sigmoid colon was defined upward from the level where the rectum turned in a transverse plane. Contrast-filled small bowel was contoured on all slices where it was visible. The presence of sigmoid colon and/or small bowel in close vicinity to or overlapping with the PTV was recorded. For each case, the dose to the sigmoid colon and small bowel was calculated. Results: the PTV was found to overlap with the sigmoid colon in 60% and with the small bowel in 19% of the cases. In these patients, mean maximum dose to the sigmoid colon was 76.2 Gy (5th-95th percentile: 70.0-80.7 Gy). Mean maximum dose to the small bowel was 74.9 Gy (5th-95th percentile: 68.0-80.0 Gy). Conclusion: when systematically investigating the anatomic position of sigmoid colon and small bowel in patients accepted for prostate irradiation, parts of both organs were often observed in close vicinity to the PTV. Apart from the rectum, these organs may be dose-limiting in prostate radiotherapy. (orig.)

Radiotherapy in prostate cancer. Innovative techniques and current controversies

Energy Technology Data Exchange (ETDEWEB)

Geinitz, Hans [Krankenhaus der Barmherzigen Schwestern, Linz (Austria). Dept. of Radiation Oncology; Linz Univ. (Austria). Medical Faculty; Roach, Mack III [California Univ., San Francisco, CA (United States). Dept. of Radiation Oncology; Van As, Nicholas (ed.) [The Institute of Cancer Research, Sutton Surrey (United Kingdom)

2015-04-01

Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

Radiotherapy-induced second cancers: are we doing enough to protect young patients?

International Nuclear Information System (INIS)

Epstein, R.; Hanham, I.; Dale, R.; Charing Cross Hospital, London

1997-01-01

This paper describes some evolving concerns about radiation-inducible carcinogenesis. These include the likelihood that low-dose radiation may be posing greater long-term hazards than higher doses; why bad luck can sometimes be dose dependent; how young patients with good-prognosis tumours can be greatest risk of radiotherapy-induced second cancers; and why the contribution of radiotherapy to second breast cancers remains a conundrum. Finally the cautionary implications of this knowledge for the future practice of radiation oncology are discussed. (UK)

Radiation dose in radiotherapy from prescription to delivery

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-08-01

Cancer incidence is increasing in developed as well as in developing countries. Cancer may be expected to become a prominent problem and this will result in public pressure for higher priorities on cancer care. In some relatively advanced developing countries radiation therapy is applied in about 50% of all detected cancer cases. Approximately half of these treatments have curative intent. Surgery and radiotherapy applied individually or combined result in the cure of about 40% of all patients. The application of chemotherapy alone has curative effects only on a small percentage of cancer patients. It is encouraging to note that the results achieved by radiation therapy show continuous improvement. This can be traced back to a number of developments: increased knowledge regarding tumour and normal tissue response to radiation, early diagnosis with improved tumour localisation, improved dosimetry and dose planning. The introduction of modern equipment has been crucial in these developments and makes possible a more accurate target delineation, better treatment planning resulting in irradiation of the Planning Target Volume (PTV) with a highly uniform dose and, simultaneously, a reduction in dose to healthy tissues outside the PTV. Experience shows that high quality radiotherapy can only be achieved if its conducted by a skilled team working closely together with good communication between various categories of staff. Therefore, seminars and training courses covering all aspects of radiotherapy and dosimetry are of great importance and should be held regionally or nationally on a regular basis. Refs, figs, tabs.

Radiation dose in radiotherapy from prescription to delivery

International Nuclear Information System (INIS)

1996-08-01

Cancer incidence is increasing in developed as well as in developing countries. Cancer may be expected to become a prominent problem and this will result in public pressure for higher priorities on cancer care. In some relatively advanced developing countries radiation therapy is applied in about 50% of all detected cancer cases. Approximately half of these treatments have curative intent. Surgery and radiotherapy applied individually or combined result in the cure of about 40% of all patients. The application of chemotherapy alone has curative effects only on a small percentage of cancer patients. It is encouraging to note that the results achieved by radiation therapy show continuous improvement. This can be traced back to a number of developments: increased knowledge regarding tumour and normal tissue response to radiation, early diagnosis with improved tumour localisation, improved dosimetry and dose planning. The introduction of modern equipment has been crucial in these developments and makes possible a more accurate target delineation, better treatment planning resulting in irradiation of the Planning Target Volume (PTV) with a highly uniform dose and, simultaneously, a reduction in dose to healthy tissues outside the PTV. Experience shows that high quality radiotherapy can only be achieved if its conducted by a skilled team working closely together with good communication between various categories of staff. Therefore, seminars and training courses covering all aspects of radiotherapy and dosimetry are of great importance and should be held regionally or nationally on a regular basis. Refs, figs, tabs

An electromechanical, patient positioning system for head and neck radiotherapy

Science.gov (United States)

Ostyn, Mark; Dwyer, Thomas; Miller, Matthew; King, Paden; Sacks, Rachel; Cruikshank, Ross; Rosario, Melvin; Martinez, Daniel; Kim, Siyong; Yeo, Woon-Hong

2017-09-01

In cancer treatment with radiation, accurate patient setup is critical for proper dose delivery. Improper arrangement can lead to disease recurrence, permanent organ damage, or lack of disease control. While current immobilization equipment often helps for patient positioning, manual adjustment is required, involving iterative, time-consuming steps. Here, we present an electromechanical robotic system for improving patient setup in radiotherapy, specifically targeting head and neck cancer. This positioning system offers six degrees of freedom for a variety of applications in radiation oncology. An analytical calculation of inverse kinematics serves as fundamental criteria to design the system. Computational mechanical modeling and experimental study of radiotherapy compatibility and x-ray-based imaging demonstrates the device feasibility and reliability to be used in radiotherapy. An absolute positioning accuracy test in a clinical treatment room supports the clinical feasibility of the system.

Intra-operative radiotherapy of malignant tumors: Past, present and perspectives

International Nuclear Information System (INIS)

Mazeron, J.J.; Le Bourgeois, J.P.; Ganem, G.

1986-01-01

Intra-operative radiotherapy consists of electron or photon radiation which is used during the operative procedure. The treatment field is arranged very precisely after critical organs have been previously arranged out of the field. The target volume includes the remaining tumor which could not be removed surgically, and the surrounding tumor bed which is also felt to be high risk for recurrence. It is preferable to have as little tumor remaining as possible before the intra-operative treatment radiation is given. Intra-operative radiotherapy was developed less than a quarter century ago in Japon, and it was later used in U.S.A. The accumulated experience in Japan and U.S.A. is rewieved here. Intra-operative radiotherapy has only recently been introduced to France. The biology, physics and medical and technical problems of intra-operative therapy are discussed [fr

Reirradiation for recurrent head and neck cancers using charged particle or photon radiotherapy.

Science.gov (United States)

Yamazaki, Hideya; Demizu, Yusuke; Okimoto, Tomoaki; Ogita, Mikio; Himei, Kengo; Nakamura, Satoaki; Suzuki, Gen; Yoshida, Ken; Kotsuma, Tadayuki; Yoshioka, Yasuo; Oh, Ryoongjin

2017-07-01

To examine the outcomes of reirradiation for recurrent head and neck cancers using different modalities. This retrospective study included 26 patients who received charged particle radiotherapy (CP) and 150 who received photon radiotherapy (117 CyberKnife radiotherapy [CK] and 36 intensity-modulated radiotherapy [IMRT]). Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias. Higher prescribed doses were used in CP than photon radiotherapy. The 1‑year overall survival (OS) rates were 67.9% for CP and 54.1% for photon radiotherapy (p = 0.15; 55% for CK and 51% for IMRT). In multivariate Cox regression, the significant prognostic factors for better survival were nasopharyngeal cancer, higher prescribed dose, and lower tumor volume. IPTW showed a statistically significant difference between CP and photon radiotherapy (p = 0.04). The local control rates for patients treated with CP and photon radiotherapy at 1 year were 66.9% (range 46.3-87.5%) and 67.1% (range 58.3-75.9%), respectively. A total of 48 patients (27%) experienced toxicity grade ≥3 (24% in the photon radiotherapy group and 46% in the CP group), including 17 patients with grade 5 toxicity. Multivariate analysis revealed that younger age and a larger planning target volume (PTV) were significant risk factors for grade 3 or worse toxicity. CP provided superior survival outcome compared to photon radiotherapy. Tumor volume, primary site (nasopharyngeal), and prescribed dose were identified as survival factors. Younger patients with a larger PTV experienced toxicity grade ≥3.

Efficient CT simulation of the four-field technique for conformal radiotherapy of prostate carcinoma

International Nuclear Information System (INIS)

Valicenti, Richard K.; Waterman, Frank M.; Croce, Raymond J.; Corn, Benjamin; Suntharalingam, Nagalingam; Curran, Walter J.

1997-01-01

Purpose: Conformal radiotherapy of prostate carcinoma relies on contouring of individual CT slices for target and normal tissue localization. This process can be very time consuming. In the present report, we describe a method to more efficiently localize pelvic anatomy directly from digital reconstructed radiographs (DRRs). Materials and Methods: Ten patients with prostate carcinoma underwent CT simulation (the spiral mode at 3 mm separation) for conformal four-field 'box' radiotherapy. The bulbous urethra and bladder were opacified with iodinated contrast media. On lateral and anteroposterior DRRs, the volume of interest (VOI) was restricted to 1.0-1.5 cm tissue thickness to optimize digital radiograph reconstruction of the prostate and seminal vesicles. By removing unessential voxel elements, this method provided direct visualization of those structures. For comparison, the targets of each patient were also obtained by contouring CT axial slices. Results: The method was successfully performed if the target structures were readily visualized and geometrically corresponded to those generated by contouring axial images. The targets in 9 of 10 patients were reliable representations of the CT-contoured volumes. One patient had 18 mm variation due to the lack of bladder opacification. Using VOIs to generate thin tissue DRRs, the time required for target and normal tissue localization was on the average less than 5 min. Conclusion: In CT simulation of the four-field irradiation technique for prostate carcinoma, thin-tissue DRRs allowed for efficient and accurate target localization without requiring individual axial image contouring. This method may facilitate positioning of the beam isocenter and provide reliable conformal radiotherapy

Left-sided breast cancer irradiation using rotational and fixed-field radiotherapy

International Nuclear Information System (INIS)

Qi, X. Sharon; Liu, Tian X.; Liu, Arthur K.; Newman, Francis; Rabinovitch, Rachel; Kavanagh, Brian; Hu, Y. Angie

2014-01-01

The 3-dimensional conformal radiotherapy (3DCRT) technique is the standard for breast cancer radiotherapy. During treatment planning, not only the coverage of the planning target volume (PTV) but also the minimization of the dose to critical structures, such as the lung, heart, and contralateral breast tissue, need to be considered. Because of the complexity and variations of patient anatomy, more advanced radiotherapy techniques are sometimes desired to better meet the planning goals. In this study, we evaluated external-beam radiation treatment techniques for left breast cancer using various delivery platforms: fixed-field including TomoDirect (TD), static intensity-modulated radiotherapy (sIMRT), and rotational radiotherapy including Elekta volumetric-modulated arc therapy (VMAT) and tomotherapy helical (TH). A total of 10 patients with left-sided breast cancer who did or did not have positive lymph nodes and were previously treated with 3DCRT/sIMRT to the entire breast were selected, their treatment was planned with Monaco VMAT, TD, and TH. Dosimetric parameters including PTV coverage, organ-at-risk (OAR) sparing, dose-volume histograms, and target minimum/maximum/mean doses were evaluated. It is found that for plans providing comparable PTV coverage, the Elekta VMAT plans were generally more inhomogeneous than the TH and TD plans. For the cases with regional node involvement, the average mean doses administered to the heart were 9.2 (± 5.2) and 8.8 (± 3.0) Gy in the VMAT and TH plans compared with 11.9 (± 6.4) and 11.8 (± 9.2) Gy for the 3DCRT and TD plans, respectively, with slightly higher doses given to the contralateral lung or breast or both. On average, the total monitor units for VMAT plans are 11.6% of those TH plans. Our studies have shown that VMAT and TH plans offer certain dosimetric advantages over fixed-field IMRT plans for advanced breast cancer requiring regional nodal treatment. However, for early-stage breast cancer fixed

Targeted radiotherapy with {sup 177} Lu-DOTA-TATE in athymic mice with induced pancreatic malignant tumours

Energy Technology Data Exchange (ETDEWEB)

Rodriguez C, J.; Murphy, C.A. de; Pedraza L, M. [Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Vasco de Quiroga No. 15, 14000 Mexico D.F. (Mexico); Ferro F, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Murphy S, E. [Hospital Santelena, 06000 Mexico D.F. (Mexico)

2006-07-01

Malignant pancreas tumours induced in athymic mice are a good model for peptide receptor targeted radiotherapy. The objective of this research was to estimate pancreatic tumour absorbed radiation doses after administration of {sup 177}Lu-DOTA-TATE in mice as a therapeutic radiopharmaceutical that could be used in humans. AR42J murine pancreas cancer cells expressing somatostatin receptors, were implanted in athymic mice (n=18) to obtain the {sup 177}Lu-DOTA-TATE biokinetics and dosimetry. To estimate its therapeutic efficacy 87 MBq were injected in a tail vein of 3 mice and 19 days p.i. there were a partial relapse. There was an epithelial and sarcoma mixed tumour in the kidneys of mouse III. The absorbed dose to tumour, kidney and pancreas was 50.5 {+-} 7.2 Gy, 17.5 {+-} 2.5 Gy and 12.6 {+-} 2.3 Gy respectively. These studies justify further therapeutic and dosimetry estimations to ensure that {sup 177}Lu-DOTA-TATE will act as expected in man considering its kidney radiotoxicity. (Author)

Clinical target volume delineation including elective nodal irradiation in preoperative and definitive radiotherapy of pancreatic cancer

Directory of Open Access Journals (Sweden)

Caravatta Luciana

2012-06-01

Full Text Available Abstract Background Radiotherapy (RT is widely used in the treatment of pancreatic cancer. Currently, recommendation has been given for the delineation of the clinical target volume (CTV in adjuvant RT. Based on recently reviewed pathologic data, the aim of this study is to propose criteria for the CTV definition and delineation including elective nodal irradiation (ENI in the preoperative and definitive treatment of pancreatic cancer. Methods The anatomical structures of interest, as well as the abdominal vasculature were identified on intravenous contrast-enhanced CT scans of two different patients with pancreatic cancer of the head and the body. To delineate the lymph node area, a margin of 10 mm was added to the arteries. Results We proposed a set of guidelines for elective treatment of high-risk nodal areas and CTV delineation. Reference CT images were provided. Conclusions The proposed guidelines could be used for preoperative or definitive RT for carcinoma of the head and body of the pancreas. Further clinical investigations are needed to validate the defined CTVs.

Monte Carlo dosimetry for synchrotron stereotactic radiotherapy of brain tumours

International Nuclear Information System (INIS)

Boudou, Caroline; Balosso, Jacques; Esteve, Francois; Elleaume, Helene

2005-01-01

A radiation dose enhancement can be obtained in brain tumours after infusion of an iodinated contrast agent and irradiation with kilovoltage x-rays in tomography mode. The aim of this study was to assess dosimetric properties of the synchrotron stereotactic radiotherapy technique applied to humans (SSR) for preparing clinical trials. We designed an interface for dose computation based on a Monte Carlo code (MCNPX). A patient head was constructed from computed tomography (CT) data and a tumour volume was modelled. Dose distributions were calculated in SSR configuration for various energy beam and iodine content in the target volume. From the calculations, it appears that the iodine-filled target (10 mg ml -1 ) can be efficiently irradiated by a monochromatic beam of energy ranging from 50 to 85 keV. This paper demonstrates the feasibility of stereotactic radiotherapy for treating deep-seated brain tumours with monoenergetic x-rays from a synchrotron

Contribution of customised dosimetry for small animal to the treatments of cancers by metabolic radiotherapy

International Nuclear Information System (INIS)

Boutaleb, Samir

2010-01-01

This research thesis first reports a bibliographical study which addressed the use of ionizing radiations in cancer therapy (evolution from ionizing radiation to metabolic radiotherapy, biological and physical parameters, and absorbed dose in metabolic radiotherapy) and the role imagery has in customised dosimetry (absorbed dose calculation methods, determination of cumulative activity, dosimetric models for S factor calculation). Then, the author presents a software which has been specifically developed for the creation of dosimetric models, and reports its validation. He reports the comparison between different dosimetric models in the case of mice. He highlights two applications of the developed tool: radio-immunotherapy and metabolic radiotherapy. He finally proposes a general discussion on the impact of small animal dosimetry on metabolic radiotherapy [fr

Intensity modulated radiotherapy for breast cancer

International Nuclear Information System (INIS)

Riou, O.; Fenoglietto, P.; Lemanski, C.; Azria, D.

2012-01-01

Intensity modulated radiotherapy (IMRT) is a technique allowing dose escalation and normal tissue sparing for various cancer types. For breast cancer, the main goals when using IMRT were to improve dose homogeneity within the breast and to enhance coverage of complex target volumes. Nonetheless, better heart and lung protections are achievable with IMRT as compared to standard irradiation for difficult cases. Three prospective randomized controlled trials of IMRT versus standard treatment showed that a better breast homogeneity can translate into better overall cosmetic results. Dosimetric and clinical studies seem to indicate a benefit of IMRT for lymph nodes irradiation, bilateral treatment, left breast and chest wall radiotherapy, or accelerated partial breast irradiation. The multiple technical IMRT solutions available tend to indicate a widespread use for breast irradiation. Nevertheless, indications for breast IMRT should be personalized and selected according to the expected benefit for each individual. (authors)

SU-E-J-76: Incorporation of Ultrasound Elastography in Target Volume Delineation for Partial Breast Radiotherapy Planning: A Comparative Study

Energy Technology Data Exchange (ETDEWEB)

Juneja, P; Harris, E; Bamber, J [The Institute of Cancer Research, London (United Kingdom); Royal Marsden NHS Foundation Trust, London (United Kingdom)

2014-06-01

Purpose: There is substantial observer variability in the delineation of target volumes for post-surgical partial breast radiotherapy because the tumour bed has poor x-ray contrast. This variability may result in substantial variations in planned dose distribution. Ultrasound elastography (USE) has an ability to detect mechanical discontinuities and therefore, the potential to image the scar and distortion in breast tissue architecture. The goal of this study was to compare USE techniques: strain elastography (SE), shear wave elastography (SWE) and acoustic radiation force impulse (ARFI) imaging using phantoms that simulate features of the tumour bed, for the purpose of incorporating USE in breast radiotherapy planning. Methods: Three gelatine-based phantoms (10% w/v) containing: a stiff inclusion (gelatine 16% w/v) with adhered boundaries, a stiff inclusion (gelatine 16% w/v) with mobile boundaries and fluid cavity inclusion (to mimic seroma), were constructed and used to investigate the USE techniques. The accuracy of the elastography techniques was quantified by comparing the imaged inclusion with the modelled ground-truth using the Dice similarity coefficient (DSC). For two regions of interest (ROI), the DSC measures their spatial overlap. Ground-truth ROIs were modelled using geometrical measurements from B-mode images. Results: The phantoms simulating stiff scar tissue with adhered and mobile boundaries and seroma were successfully developed and imaged using SE and SWE. The edges of the stiff inclusions were more clearly visible in SE than in SWE. Subsequently, for all these phantoms the measured DSCs were found to be higher for SE (DSCs: 0.91–0.97) than SWE (DSCs: 0.68–0.79) with an average relative difference of 23%. In the case of seroma phantom, DSC values for SE and SWE were similar. Conclusion: This study presents a first attempt to identify the most suitable elastography technique for use in breast radiotherapy planning. Further analysis will

SU-E-J-76: Incorporation of Ultrasound Elastography in Target Volume Delineation for Partial Breast Radiotherapy Planning: A Comparative Study

International Nuclear Information System (INIS)

Juneja, P; Harris, E; Bamber, J

2014-01-01

Purpose: There is substantial observer variability in the delineation of target volumes for post-surgical partial breast radiotherapy because the tumour bed has poor x-ray contrast. This variability may result in substantial variations in planned dose distribution. Ultrasound elastography (USE) has an ability to detect mechanical discontinuities and therefore, the potential to image the scar and distortion in breast tissue architecture. The goal of this study was to compare USE techniques: strain elastography (SE), shear wave elastography (SWE) and acoustic radiation force impulse (ARFI) imaging using phantoms that simulate features of the tumour bed, for the purpose of incorporating USE in breast radiotherapy planning. Methods: Three gelatine-based phantoms (10% w/v) containing: a stiff inclusion (gelatine 16% w/v) with adhered boundaries, a stiff inclusion (gelatine 16% w/v) with mobile boundaries and fluid cavity inclusion (to mimic seroma), were constructed and used to investigate the USE techniques. The accuracy of the elastography techniques was quantified by comparing the imaged inclusion with the modelled ground-truth using the Dice similarity coefficient (DSC). For two regions of interest (ROI), the DSC measures their spatial overlap. Ground-truth ROIs were modelled using geometrical measurements from B-mode images. Results: The phantoms simulating stiff scar tissue with adhered and mobile boundaries and seroma were successfully developed and imaged using SE and SWE. The edges of the stiff inclusions were more clearly visible in SE than in SWE. Subsequently, for all these phantoms the measured DSCs were found to be higher for SE (DSCs: 0.91–0.97) than SWE (DSCs: 0.68–0.79) with an average relative difference of 23%. In the case of seroma phantom, DSC values for SE and SWE were similar. Conclusion: This study presents a first attempt to identify the most suitable elastography technique for use in breast radiotherapy planning. Further analysis will

The molecular mechanism of gene-radiotherapy of tumor

International Nuclear Information System (INIS)

Zhu Xian

2004-01-01

Gene-radiotherapy of tumor is a new method which is induced by ionizing radiation. The molecular mechanism is to activate various molecular target by many ways and induce the apoptosis of tumor cell. It is a gene therapy based on the radiation-inducible property of the Egr-1 gene. It has good application prospect in therapy of tumor

PLANNING NATIONAL RADIOTHERAPY SERVICES

Directory of Open Access Journals (Sweden)

Eduardo eRosenblatt

2014-11-01

Full Text Available 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 centres 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 centres, equipment, staff, education pr

Bystander effects and radiotherapy.

Science.gov (United States)

Marín, Alicia; Martín, Margarita; Liñán, Olga; Alvarenga, Felipe; López, Mario; Fernández, Laura; Büchser, David; Cerezo, Laura

2015-01-01

Radiation-induced bystander effects are defined as biological effects expressed after irradiation by cells whose nuclei have not been directly irradiated. These effects include DNA damage, chromosomal instability, mutation, and apoptosis. There is considerable evidence that ionizing radiation affects cells located near the site of irradiation, which respond individually and collectively as part of a large interconnected web. These bystander signals can alter the dynamic equilibrium between proliferation, apoptosis, quiescence or differentiation. The aim of this review is to examine the most important biological effects of this phenomenon with regard to areas of major interest in radiotherapy. Such aspects include radiation-induced bystander effects during the cell cycle under hypoxic conditions when administering fractionated modalities or combined radio-chemotherapy. Other relevant aspects include individual variation and genetics in toxicity of bystander factors and normal tissue collateral damage. In advanced radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), the high degree of dose conformity to the target volume reduces the dose and, therefore, the risk of complications, to normal tissues. However, significant doses can accumulate out-of-field due to photon scattering and this may impact cellular response in these regions. Protons may offer a solution to reduce out-of-field doses. The bystander effect has numerous associated phenomena, including adaptive response, genomic instability, and abscopal effects. Also, the bystander effect can influence radiation protection and oxidative stress. It is essential that we understand the mechanisms underlying the bystander effect in order to more accurately assess radiation risk and to evaluate protocols for cancer radiotherapy.

The combination of chemotherapy and radiotherapy towards more efficient drug delivery.

Science.gov (United States)

Cao, Wei; Gu, Yuwei; Meineck, Myriam; Xu, Huaping

2014-01-01

Research on anticancer therapies has advanced significantly in recent years. New therapeutic platforms that can further improve the health of patients are still highly demanded. We propose the idea of combining regular chemotherapy with radiation therapy to minimize side effects as well as increase drug-delivery efficiency. In this Focus Review, we seek to provide an overview of recent advances that can combine chemotherapy and radiotherapy. We begin by reviewing the current state of systems that can combine chemotherapy and gamma radiation. Among them, diselenide-containing polymers are highlighted as sensitive drug-delivery vehicles that can disassemble under gamma radiation. Then X-ray responsive materials as promising alternative systems are summarized, including X-ray responsive drug-delivery vehicles, prodrugs that can be activated by X-rays, and radiation-site-targeting systems. Finally, we describe strategies that involve phototherapies. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Factors influencing conformity index in radiotherapy for non-small cell lung cancer.

LENUS (Irish Health Repository)

Brennan, Sinead M

2010-01-01

The radiotherapy conformity index (CI) is a useful tool to quantitatively assess the quality of radiotherapy treatment plans, and represents the relationship between isodose distributions and target volume. A conformity index of unity implies high planning target volume (PTV) coverage and minimal unnecessary irradiation of surrounding tissues. We performed this analysis to describe the CI for lung cancer 3-dimensional conformal radiotherapy (3DCRT) and to identify clinical and technical determinants of CI, as it is not known which factors are associated with good quality 3D conformal radiotherapy treatment planning. Radiotherapy treatment plans from a database of 52 patients with inoperable Stage 1 to 3b lung cancer, on a hypofractionated 3DCRT trial were evaluated. A CI was calculated for all plans using the definition of the ICRU 62:CI = (TV\\/PTV), which is the quotient of the treated volume (TV) and the PTV. Data on patient, tumor, and planning variables, which could influence CI, were recorded and analyzed. Mean CI was 2.01 (range = 1.06-3.8). On univariate analysis, PTV (p = 0.023), number of beams (p = 0.036), medial vs. lateral tumor location (p = 0.016), and increasing tumor stage (p = 0.041) were associated with improved conformity. On multiple regression analysis, factors found to be associated with CI included central vs. peripheral tumor location (p = 0.041) and PTV size (p = 0.058). The term 3DCRT is used routinely in the literature, without any indication of the degree of conformality. We recommend routine reporting of conformity indices. Conformity indices may be affected by both planning variables and tumor factors.

Image guided radiotherapy: equipment specifications and performance - an analysis of the dosimetric consequences of anatomic variations during head-and-neck radiotherapy treatment

International Nuclear Information System (INIS)

Marguet, Maud

2009-01-01

Anatomic variations during head-and-neck radiotherapy treatment may compromise the delivery of the planned dose distribution, particularly in the case of IMRT treatments. The aim of this thesis was to establish 'dosimetric indicators' to identify patients who delivered dose deviates from the planned dose, to allow an eventual re-optimisation of the patient's dosimetry, if necessary, during the course of their radiotherapy treatment. These anatomic variations were monitored by regular acquisition of 3D patient images using an onboard imaging system, for which a rigorous quality control program was implemented. The patient dose distribution analysis and comparison was performed using a modified gamma index technique which was named gammaLSC3D. This improved gamma index technique quantified and identified the location of changes in the dose distribution in a stack of 2D images, with particular reference to the target volume (PTV) or organs at risk (parotids). The changes observed in the dose distribution for the PTV or parotids were then analysed and presented in the form of gamma-volume histograms in order to facilitate the follow up of dosimetric changes during the radiotherapy treatment. This analysis method has been automated, and is applicable in clinical routine to follow dose variations during head and neck radiotherapy treatment. (author) [fr

Does Motion Assessment With 4-Dimensional Computed Tomographic Imaging for Non–Small Cell Lung Cancer Radiotherapy Improve Target Volume Coverage?

Directory of Open Access Journals (Sweden)

Naseer Ahmed

2017-03-01

Full Text Available Introduction: Modern radiotherapy with 4-dimensional computed tomographic (4D-CT image acquisition for non–small cell lung cancer (NSCLC captures respiratory-mediated tumor motion to provide more accurate target delineation. This study compares conventional 3-dimensional (3D conformal radiotherapy (3DCRT plans generated with standard helical free-breathing CT (FBCT with plans generated on 4D-CT contoured volumes to determine whether target volume coverage is affected. Materials and methods: Fifteen patients with stage I to IV NSCLC were enrolled in the study. Free-breathing CT and 4D-CT data sets were acquired at the same simulation session and with the same immobilization. Gross tumor volume (GTV for primary and/or nodal disease was contoured on FBCT (GTV_3D. The 3DCRT plans were obtained, and the patients were treated according to our institution’s standard protocol using FBCT imaging. Gross tumor volume was contoured on 4D-CT for primary and/or nodal disease on all 10 respiratory phases and merged to create internal gross tumor volume (IGTV_4D. Clinical target volume margin was 5 mm in both plans, whereas planning tumor volume (PTV expansion was 1 cm axially and 1.5 cm superior/inferior for FBCT-based plans to incorporate setup errors and an estimate of respiratory-mediated tumor motion vs 8 mm isotropic margin for setup error only in all 4D-CT plans. The 3DCRT plans generated from the FBCT scan were copied on the 4D-CT data set with the same beam parameters. GTV_3D, IGTV_4D, PTV, and dose volume histogram from both data sets were analyzed and compared. Dice coefficient evaluated PTV similarity between FBCT and 4D-CT data sets. Results: In total, 14 of the 15 patients were analyzed. One patient was excluded as there was no measurable GTV. Mean GTV_3D was 115.3 cm 3 and mean IGTV_4D was 152.5 cm 3 ( P = .001. Mean PTV_3D was 530.0 cm 3 and PTV_4D was 499.8 cm 3 ( P = .40. Both gross primary and nodal disease analyzed separately were larger

Markerless gating for lung cancer radiotherapy based on machine learning techniques

International Nuclear Information System (INIS)

Lin Tong; Li Ruijiang; Tang Xiaoli; Jiang, Steve B; Dy, Jennifer G

2009-01-01

In lung cancer radiotherapy, radiation to a mobile target can be delivered by respiratory gating, for which we need to know whether the target is inside or outside a predefined gating window at any time point during the treatment. This can be achieved by tracking one or more fiducial markers implanted inside or near the target, either fluoroscopically or electromagnetically. However, the clinical implementation of marker tracking is limited for lung cancer radiotherapy mainly due to the risk of pneumothorax. Therefore, gating without implanted fiducial markers is a promising clinical direction. We have developed several template-matching methods for fluoroscopic marker-less gating. Recently, we have modeled the gating problem as a binary pattern classification problem, in which principal component analysis (PCA) and support vector machine (SVM) are combined to perform the classification task. Following the same framework, we investigated different combinations of dimensionality reduction techniques (PCA and four nonlinear manifold learning methods) and two machine learning classification methods (artificial neural networks-ANN and SVM). Performance was evaluated on ten fluoroscopic image sequences of nine lung cancer patients. We found that among all combinations of dimensionality reduction techniques and classification methods, PCA combined with either ANN or SVM achieved a better performance than the other nonlinear manifold learning methods. ANN when combined with PCA achieves a better performance than SVM in terms of classification accuracy and recall rate, although the target coverage is similar for the two classification methods. Furthermore, the running time for both ANN and SVM with PCA is within tolerance for real-time applications. Overall, ANN combined with PCA is a better candidate than other combinations we investigated in this work for real-time gated radiotherapy.

Effect of radiotherapy on lymphocyte cytotoxicity in vitro

Energy Technology Data Exchange (ETDEWEB)

Wasserman, J; Melen, B [Central Microbiological Laboratory, Stockholm County Council (Sweden); Blomgren, H; Glas, U; Perlmann, P

1975-11-01

The cytotoxic functions of highly purified blood lymphocytes from patients with breast cancer were studied before and after radiotherapy. Addition of PHA or of rabbit antibodies to target cells (chicken erythrocytes) were chosen as two means of inducing lymphocyte cytotoxicity in vitro. The proportion of T and non-T lymphocytes was determined by means of E and EAC rosette tests. The antibody-induced cytotoxicity of lymphocytes decreased following radiotherapy while that mediated by PHA remained unchanged. There was some reduction in the percentage of EAC rosette-forming cells. These results, as well as earlier observations, suggest that the decrease in the peripheral blood of the proportion of lymphocytes with receptors for activated complement is responsible for changes in the antibody-mediated lymphocyte cytotoxicity.

Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

Energy Technology Data Exchange (ETDEWEB)

Yim, Jackie; Suttie, Clare; Bromley, Regina; Morgia, Marita; Lamoury, Gillian [Department of Radiation Oncology, Royal North Shore Hospital, St Leonards, New South Wales (Australia)

2015-09-15

We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with the 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D{sub 105%} and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT.

Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index

International Nuclear Information System (INIS)

Yim, Jackie; Suttie, Clare; Bromley, Regina; Morgia, Marita; Lamoury, Gillian

2015-01-01

We report on a retrospective dosimetric study, comparing 3D conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (hIMRT). We evaluated plans based on their planning target volume coverage, dose homogeneity, dose to organs at risk (OARs) and exposure of normal tissue to radiation. The Homogeneity Index (HI) was used to assess the dose homogeneity in the target region, and we describe a new index, the normal tissue index (NTI), to assess the dose in the normal tissue inside the tangent treatment portal. Plans were generated for 25 early-stage breast cancer patients, using a hIMRT technique. These were compared with the 3DCRT plans of the treatment previously received by the patients. Plan quality was evaluated using the HI, NTI and dose to OARs. The hIMRT technique was significantly more homogenous than the 3DCRT technique, while maintaining target coverage. The hIMRT technique was also superior at minimising the amount of tissue receiving D 105% and above (P < 0.0001). The ipsilateral lung and contralateral breast maximum were significantly lower in the hIMRT plans (P < 0.05 and P < 0.005), but the 3DCRT technique achieved a lower mean heart dose in left-sided breast cancer patients (P < 0.05). Hybrid intensity modulated radiotherapy plans achieved improved dose homogeneity compared to the 3DCRT plans and superior outcome with regard to dose to normal tissues. We propose that the addition of both HI and NTI in evaluating the quality of intensity modulated radiotherapy (IMRT) breast plans provides clinically relevant comparators which more accurately reflect the new paradigm of treatment goals and outcomes in the era of breast IMRT

Primary and secondary prevention of acute complications of radiotherapy of head and neck cancers; Prevention primaire et secondaire des complications aigues de la radiotherapie des cancers de la tete et du cou

Energy Technology Data Exchange (ETDEWEB)

Lambrexhe, M.; Frederick, B.; Burie, D.; Cavuto, C.; Rob, L.; Rasquin, I.; Coiffier, N.; Untereiner, M. [Centre national de Radiotherapie, Centre Francois-Baclesse (CFB), Esch-sur-Alzette (Luxembourg)

2009-10-15

Purpose: the standard treatment of head and neck cancers associates a 70 Gy irradiation and weekly concomitant chemotherapy by 5-fluoro-uracils and cisplatin or targeted therapy by Erbitux. A retrospective study realised at the Francois Baclesse center in 2004-2005 for 84 patients suffering of ear-nose-throat cancers whom treatment was a concomitant chemoradiotherapy, showed the noxious effects of the treatment on the patients nutritional situation: weight loss for 90% of patients; temporary interruption or definitive stop of radiotherapy for 28% of patients. based on this observation, a preventive approach of the nutritional risk was implemented. The objective was to reduce the malnutrition risk linked to radiotherapy associated to chemotherapy or to the targeted therapy. (N.C.)

Prostate cancer: variables to keep in mind at the moment to decide the external radiotherapy dose

International Nuclear Information System (INIS)

Donato, H.; Barros, J.M.; Fernandez Bibiloni, C.; Barrios, E.; Martinez, A.; Broda, E.; Cardiello, C.; Alva, R.; Chiozza, J.; Filomia, M.L.; Rafailovici, L.; Dosoretz, B.

2007-01-01

The objective of this work is to evaluate forecast factors and other variables in the decision of the final dose for prostate cancer treatment with 3D conformal radiotherapy techniques of modulated intensity. To determine the optimal dose, direct and indirect variables related to the disease should be considered. Also the equipment and the radiotherapy technique will impact on this decision [es

Objective assessment of cosmetic outcome after targeted intraoperative radiotherapy in breast cancer

DEFF Research Database (Denmark)

Keshtgar, Mohammed R S; Williams, Norman R; Bulsara, Max

2013-01-01

and thus impair cosmesis further, so we objectively evaluated the aesthetic outcome of patients within the TARGIT randomised controlled trial. We have used an objective assessment tool for evaluation of cosmetic outcome. Frontal digital photographs were taken at baseline (before TARGIT or EBRT) and yearly...... in a randomised setting, the aesthetic outcome of patients demonstrates that those treated with TARGIT have a superior cosmetic result to those patients who received conventional external beam radiotherapy....

A case of laryngeal palsy and persistent aspiration pneumonia following radiotherapy for laryngeal carcinoma

International Nuclear Information System (INIS)

Nakao, Kazunari; Tayama, Niro; Mizuno, Masahiro; Niimi, Seiji.

1997-01-01

A 80-year-old man developed impairment in his laryngeal movement, vocal fold fixation and severe misdeglutition after radiotherapy for laryngeal carcinoma. Despite of several surgical treatments for aspiration pneumonia, the misdeglutition did not cease because of the stiffness in his larynx until a laryngectomy was finally performed. The resected larynx showed marked fibrosis, and it was considered as a late complication of radiotherapy. The treatment course in this difficult case is discussed. (author)

Brainstem tolerance to conformal radiotherapy of skull base tumors

International Nuclear Information System (INIS)

Debus, J.; Hug, E.B.; Liebsch, N.J.; O'Farrel, D.; Finkelstein, D.; Efird, J.; Munzenrider, J.E.

1997-01-01

Purpose: The aim of this study was to analyze the long-term incidence of brainstem toxicity in patients treated for skull base tumors with high dose conformal radiotherapy. Methods and Materials: Between 1974 and 1995, 367 patients with chordomas (n = 195) and chondrosarcomas (n = 172) of the base of skull have been treated with combined megavoltage photon and 160 MeV proton radiotherapy. Following 3D treatment planning with delineation of target volumes and critical nontarget structures dose distributions and dose-volume histograms were calculated. Radiotherapy was given an 1.8 Gy or CGE (=Cobalt Gray Equivalent) dose per fraction, with prescribed target doses ranging from 63 CGE to 79.2 CGE (mean = 67.8 CGE). Doses to the brainstem surface were limited to ≤64 CGE and to the brainstem center to ≤53 CGE. Results: Follow-up time ranged from 6 months to 21.4 years (mean = 42.5 months). Brainstem toxicity was observed in 17 of 367 patients attributable to treatment, resulting in death of three patients. Actuarial rates of 5 and 10-year high-grade toxicity-free survival were 94 and 88%, respectively. Increased risk of brainstem toxicity was significantly associated with maximum dose to brainstem, volume of brainstem receiving ≥50 CGE, ≥55 CGE, and ≥60 CGE, number of surgical procedures, and prevalence of diabetes or high blood pressure. Multivariate analysis identified three independent factors as important prognosticators: number of surgical procedures (p < 0.001), volume of the brainstem receiving 60 CGE (p < 0.001), and prevalence of diabetes (p < 0.01). Conclusions: Tolerance of brainstem to fractionated radiotherapy appears to be a steep function of tissue volume included in high dose regions rather than the maximum dose of brainstem alone. In addition, presence of predisposing factors as well as extent of surgical manipulation can significantly lower brainstem tolerance in the individual patient

Treatment outcome in patients with vulvar cancer: comparison of concurrent radiotherapy to postoperative radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Lee, Ja Young; Kim, Sung Hwan; Kim, Ki Won; Park, Dong Choon; Yoon, Joo Hee; Yoon, Sei Chul [St. Vincent' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of); Yu, Mina [St. Mary' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of)

2012-03-15

To evaluate outcome and morbidity in patients with vulvar cancer treated with radiotherapy, concurrent chemoradiotherapy or postoperative radiotherapy. The records of 24 patients treated with radiotherapy for vulvar cancer between July 1993 and September 2009 were retrospectively reviewed. All patients received once daily 1.8-4 Gy fractions external beam radiotherapy to median 51.2 Gy (range, 19.8 to 81.6 Gy) on pelvis and inguinal nodes. Seven patients were treated with primary concurrent chemoradiotherapy, one patient was treated with primary radiotherapy alone, four patients received palliative radiotherapy, and twelve patients were treated with postoperative radiotherapy. Twenty patients were eligible for response evaluation. Response rate was 55% (11/20). The 5-year disease free survival was 42.2% and 5-year overall survival was 46.2%, respectively. Fifty percent (12/24) experienced with acute skin complications of grade III or more during radiotherapy. Late complications were found in 8 patients. 50% (6/12) of patients treated with lymph node dissection experienced severe late complications. One patient died of sepsis from lymphedema. However, only 16.6% (2/12) of patients treated with primary radiotherapy developed late complications. Outcome of patients with vulvar cancer treated with radiotherapy showed relatively good local control and low recurrence. Severe late toxicities remained higher in patients treated with both node dissection and radiotherapy.

Poster - 32: Atlas Selection for Automated Segmentation of Pelvic CT for Prostate Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Mallawi, Abrar; Farrell, TomTom; Diamond, Kevin-Ross; Wierzbicki, Marcin [McMaster University / National Guard Health Affairs, Radiation Oncology Department, Riyadh, Saudi Arabia, McMaster University / Juravinski Cancer Centre, McMaster University / Juravinski Cancer Centre, McMaster University / Juravinski Cancer Centre (Saudi Arabia)

2016-08-15

Atlas based-segmentation has recently been evaluated for use in prostate radiotherapy. In a typical approach, the essential step is the selection of an atlas from a database that the best matches of the target image. This work proposes an atlas selection strategy and evaluate it impacts on final segmentation accuracy. Several anatomical parameters were measured to indicate the overall prostate and body shape, all of these measurements obtained on CT images. A brute force procedure was first performed for a training dataset of 20 patients using image registration to pair subject with similar contours; each subject was served as a target image to which all reaming 19 images were affinity registered. The overlap between the prostate and femoral heads was quantified for each pair using the Dice Similarity Coefficient (DSC). Finally, an atlas selection procedure was designed; relying on the computation of a similarity score defined as a weighted sum of differences between the target and atlas subject anatomical measurement. The algorithm ability to predict the most similar atlas was excellent, achieving mean DSCs of 0.78 ± 0.07 and 0.90 ± 0.02 for the CTV and either femoral head. The proposed atlas selection yielded 0.72 ± 0.11 and 0.87 ± 0.03 for CTV and either femoral head. The DSC obtained with the proposed selection method were slightly lower than the maximum established using brute force, but this does not include potential improvements expected with deformable registration. The proposed atlas selection method provides reasonable segmentation accuracy.

Poster - 32: Atlas Selection for Automated Segmentation of Pelvic CT for Prostate Radiotherapy

International Nuclear Information System (INIS)

Mallawi, Abrar; Farrell, TomTom; Diamond, Kevin-Ross; Wierzbicki, Marcin

2016-01-01

Atlas based-segmentation has recently been evaluated for use in prostate radiotherapy. In a typical approach, the essential step is the selection of an atlas from a database that the best matches of the target image. This work proposes an atlas selection strategy and evaluate it impacts on final segmentation accuracy. Several anatomical parameters were measured to indicate the overall prostate and body shape, all of these measurements obtained on CT images. A brute force procedure was first performed for a training dataset of 20 patients using image registration to pair subject with similar contours; each subject was served as a target image to which all reaming 19 images were affinity registered. The overlap between the prostate and femoral heads was quantified for each pair using the Dice Similarity Coefficient (DSC). Finally, an atlas selection procedure was designed; relying on the computation of a similarity score defined as a weighted sum of differences between the target and atlas subject anatomical measurement. The algorithm ability to predict the most similar atlas was excellent, achieving mean DSCs of 0.78 ± 0.07 and 0.90 ± 0.02 for the CTV and either femoral head. The proposed atlas selection yielded 0.72 ± 0.11 and 0.87 ± 0.03 for CTV and either femoral head. The DSC obtained with the proposed selection method were slightly lower than the maximum established using brute force, but this does not include potential improvements expected with deformable registration. The proposed atlas selection method provides reasonable segmentation accuracy.

Low-level laser therapy in the prevention of radiotherapy-induced xerostomia and oral mucositis

International Nuclear Information System (INIS)

Lopes, Carlos de Oliveira; Mas, Josepa Rigau I.; Zangaro, Renato Amaro

2006-01-01

Objective: to verify if the use of InGaAIP laser with 685 nm wave length can reduce the xerostomy incidence, the oral mucositis severity and the pain related to mucositis in patients with head and neck cancer submitted to radiotherapy. Objective: sixty patients presenting head and neck carcinoma were submitted to radiotherapy with daily doses of 1.8 to 2.0 Gy and a final dose of 45 to 72 Gy. The salivary volume was evaluated in the first and fifteenth days, at the end of the treatment and after 15 and 30 days. The oral mucositis was evaluated on a weekly basis. Twenty-nine patients were submitted to radiotherapy without laser and 31 were submitted to radiotherapy and laser with daily doses of 2 joules/cm 2 in predetermined areas of the oral mucosa and the parotid and submandibular glands. Results: in the group submitted to radiotherapy and laser the incidence of mucositis (p < 0.001) and pain (p < 0.016) was significantly lower and the salivary volume (p < 0.001) was kept higher during and after the treatment. Conclusion: the group of patients submitted to radiotherapy and laser had lower incidence of xerostomy, oral mucositis and pain when compared to the group treated with radiotherapy without laser, producing statistically significant results. (author)

External beam radiotherapy of localized prostatic adenocarcinoma. Evaluation of conformal therapy, field number and target margins

International Nuclear Information System (INIS)

Lennernaes, B.; Rikner, G.; Letocha, H.; Nilsson, S.

1995-01-01

The purpose of the present study was to identify factors of importance in the planning of external beam radiotherapy of prostatic adenocarcinoma. Seven patients with urogenital cancers were planned for external radiotherapy of the prostate. Four different techniques were used, viz. a 4-field box technique and four-, five- or six-field conformal therapy set-ups combined with three different margins (1-3 cm). The evaluations were based on the doses delivered to the rectum and the urinary bladder. A normal tissue complication probability (NTCP) was calculated for each plan using Lyman's dose volume reduction method. The most important factors that resulted in a decrease of the dose delivered to the rectum and the bladder were the use of conformal therapy and smaller margins. Conformal therapy seemed more important for the dose distribution in the urinary bladder. Five- and six-field set-ups were not significantly better than those with four fields. NTCP calculations were in accordance with the evaluation of the dose volume histograms. To conclude, four-field conformal therapy utilizing reduced margins improves the dose distribution to the rectum and the urinary bladder in the radiotherapy of prostatic adenocarcinoma. (orig.)

Dosimetric and geometric evaluation of a hybrid strategy of offline adaptive planning and online image guidance for prostate cancer radiotherapy

International Nuclear Information System (INIS)

Liu Han; Wu Qiuwen

2011-01-01

For prostate cancer patients, online image-guided (IG) radiotherapy has been widely used in clinic to correct the translational inter-fractional motion at each treatment fraction. For uncertainties that cannot be corrected online, such as rotation and deformation of the target volume, margins are still required to be added to the clinical target volume (CTV) for the treatment planning. Offline adaptive radiotherapy has been implemented to optimize the treatment for each individual patient based on the measurements at early stages of treatment process. It has been shown that offline adaptive radiotherapy can effectively reduce the required margin. Recently a hybrid strategy of offline adaptive replanning and online IG was proposed and the geometric evaluation was performed. It was found that the planning margins can further be reduced by 1-2 mm compared to online IG only strategy. The purpose of this study was to investigate the dosimetric benefits of such a hybrid strategy on the target and organs at risk. A total of 420 repeated helical computed tomography scans from 28 patients were included in the study. Both low-risk patients (LRP, CTV = prostate) and intermediate-risk patients (IRP, CTV = prostate + seminal vesicles, SV) were included in the simulation. Two registration methods, based on center-of-mass shift of prostate only and prostate plus SV, were performed for IRP. The intensity-modulated radiotherapy was used in the simulation. Criteria on both cumulative and fractional doses were evaluated. Furthermore, the geometric evaluation was extended to investigate the optimal number of fractions necessary to construct the internal target volume (ITV) for the hybrid strategy. The dosimetric margin improvement was smaller than its geometric counterpart and was in the range of 0-1 mm. The optimal number of fractions necessary for the ITV construction is 2 for LRPs and 3-4 for IRPs in a hypofractionation protocol. A new cumulative index of target volume was proposed

Quo vadis radiotherapy? Technological advances and the rising problems in cancer management.

Science.gov (United States)

Allen, Barry J; Bezak, Eva; Marcu, Loredana G

2013-01-01

Despite the latest technological advances in radiotherapy, cancer control is still challenging for several tumour sites. The survival rates for the most deadly cancers, such as ovarian and pancreatic, have not changed over the last decades. The solution to the problem lies in the change of focus: from local treatment to systemic therapy. The aim of this paper is to present the current status as well as the gaps in radiotherapy and, at the same time, to look into potential solutions to improve cancer control and survival. The currently available advanced radiotherapy treatment techniques have been analysed and their cost-effectiveness discussed. The problem of systemic disease management was specifically targeted. Clinical studies show limited benefit in cancer control from hadron therapy. However, targeted therapies together with molecular imaging could improve treatment outcome for several tumour sites while controlling the systemic disease. The advances in photon therapy continue to be competitive with the much more expensive hadron therapy. To justify the cost effectiveness of proton/heavy ion therapy, there is a need for phase III randomised clinical trials. Furthermore, the success of systemic disease management lies in the fusion between radiation oncology technology and microbiology.

Radiotherapy in small countries.

Science.gov (United States)

Barton, Michael B; Zubizarreta, Eduardo H; Polo Rubio, J Alfredo

2017-10-01

To examine the availability of radiotherapy in small countries. A small country was defined as a country with a population less than one million persons. The economic status of each country was defined using the World Bank Classification. The number of cancers in each country was obtained from GLOBOCAN 2012. The number of cancer cases with an indication or radiotherapy was calculated using the CCORE model. There were 41 countries with a population of under 1 million; 15 were classified as High Income, 15 Upper Middle Income, 10 Lower Middle Income and one Low Income. 28 countries were islands. Populations ranged from 799 (Holy See) to 886450 (Fiji) and the total number of cancer cases occurring in small countries was 21,043 (range by country from 4 to 2476). Overall the total number of radiotherapy cases in small countries was 10982 (range by country from 2 to 1239). Radiotherapy was available in all HIC islands with 80 or more new cases of cancer in 2012 but was not available in any LMIC island. Fiji was the only LMIC island with a large radiotherapy caseload. Similar caseloads in non-island LMIC all had radiotherapy services. Most non-island HIC did not have radiotherapy services presumably because of the easy access to radiotherapy in neighbouring countries. There are no radiotherapy services in any LMIC islands. Copyright © 2017. Published by Elsevier Ltd.

Primary and secondary prevention of acute complications of radiotherapy of head and neck cancers

International Nuclear Information System (INIS)

Lambrexhe, M.; Frederick, B.; Burie, D.; Cavuto, C.; Rob, L.; Rasquin, I.; Coiffier, N.; Untereiner, M.

2009-01-01

Purpose: the standard treatment of head and neck cancers associates a 70 Gy irradiation and weekly concomitant chemotherapy by 5-fluoro-uracils and cisplatin or targeted therapy by Erbitux. A retrospective study realised at the Francois Baclesse center in 2004-2005 for 84 patients suffering of ear-nose-throat cancers whom treatment was a concomitant chemoradiotherapy, showed the noxious effects of the treatment on the patients nutritional situation: weight loss for 90% of patients; temporary interruption or definitive stop of radiotherapy for 28% of patients. based on this observation, a preventive approach of the nutritional risk was implemented. The objective was to reduce the malnutrition risk linked to radiotherapy associated to chemotherapy or to the targeted therapy. (N.C.)

Chromatin-regulating proteins as targets for cancer therapy

International Nuclear Information System (INIS)

Oike, Takahiro; Ogiwara, Hideaki; Kohno, Takashi; Amornwichet, Napapat; Nakano, Takashi

2014-01-01

Chromatin-regulating proteins represent a large class of novel targets for cancer therapy. In the context of radiotherapy, acetylation and deacetylation of histones by histone acetyltransferases (HATs) and histone deacetylases (HDACs) play important roles in the repair of DNA double-strand breaks generated by ionizing irradiation, and are therefore attractive targets for radiosensitization. Small-molecule inhibitors of HATs (garcinol, anacardic acid and curcumin) and HDACs (vorinostat, sodium butyrate and valproic acid) have been shown to sensitize cancer cells to ionizing irradiation in preclinical models, and some of these molecules are being tested in clinical trials, either alone or in combination with radiotherapy. Meanwhile, recent large-scale genome analyses have identified frequent mutations in genes encoding chromatin-regulating proteins, especially in those encoding subunits of the SWI/SNF chromatin-remodeling complex, in various human cancers. These observations have driven researchers toward development of targeted therapies against cancers carrying these mutations. DOT1L inhibition in MLL-rearranged leukemia, EZH2 inhibition in EZH2-mutant or MLL-rearranged hematologic malignancies and SNF5-deficient tumors, BRD4 inhibition in various hematologic malignancies, and BRM inhibition in BRG1-deficient tumors have demonstrated promising anti-tumor effects in preclinical models, and these strategies are currently awaiting clinical application. Overall, the data collected so far suggest that targeting chromatin-regulating proteins is a promising strategy for tomorrow's cancer therapy, including radiotherapy and molecularly targeted chemotherapy. (author)

Status of Radiotherapy around the World: Radiotherapy in China. Chapter 25.6

International Nuclear Information System (INIS)

Zhu, Ci; Yin, Wei Bo; Chen, Bo; Zhang, Chun Li; Zhang, Hong Zhi; Li, Ye Xiong

2017-01-01

China’s experience of using radiotherapy to treat cancer began with the installation of the first superficial X ray machine at Peking Union Medical College Hospital in early 1920, followed by the first 200 kV deep X ray machine installed at the French Hospital in Shanghai in 1923, and the first Chinese radiotherapy department established at the Affiliated Hospital of Peking University in 1932. However, the field of radiotherapy in China was still in its infancy between the 1930s and 1960s, as all operating machines were imported from foreign countries, making radiotherapy very difficult to access for cancer patients. Progress was slow until the mid-1970s, when the first batch of megavoltage machines (cobalt-60 machines and linacs) was produced by Chinese manufacturers. Owing to the efforts of radiotherapy pioneers such as Wu Huanxing, Gu Xianzhi, Liu Taifu, and Yin Weibo, who brought radiotherapy to China and shaped how Chinese patients would be treated today, radiotherapy was installed as one of the mainstream modalities of cancer treatment. In 1986, the China Society for Radiation Oncology (CSTRO) was founded, indicating that a network advancing radiation oncology practice in China was taking shape. One year later, the first issue of the Chinese Journal of Radiation Oncology was published, offering a platform for the timely exchange and sharing of laboratory and clinical research outcomes among radiation oncology professions across the country. During the past two decades, with the introduction of the gamma knife and stereotactic radiotherapy, 3-D conformal radiotherapy, IMRT, IGRT and other advanced techniques, China experienced not only a big jump in its radiotherapy equipment and facilities, but also a dramatic growth in the excellence of radiation oncology specialist staff nationwide

Dosimetry at the location of secondary tumors after radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Baas, H W; Davelaar, J J; Broerse, J J; Noordijk, E M [University Hospital, Leiden (Netherlands). Dept. of Clinical Oncology

1995-12-01

After a latency period of many years the incidence of a secondary tumor is considered a serious late effect of radiotherapy. Analysis of about 200 patients, treated by radiotherapy for Hodgkin`s disease in our hospital, shows an actuarial risk for the incidence of a secondary tumor of about 7% after 10 years. The chance of tumor induction depends on the dose at the location of the tumor and therefore a good dose estimation is mandatory. Radiotherapy was given with Co-60 in the early years and with linear accelerators thereafter, exposing the target areas to 36 - 40 Gy. For dose estimations at the penumbra and outside the beam, where tumor incidence is expected to be high, we used a.o. Monte Carlo calculations. We developed an EGS4 computer simulation for a treatment beam from a linear accelerator irradiating a mathematical phantom representing the patient geometry (GSF ADAM phantom). The isodose curves at certain energies were obtained for a water phantom and fitted quite well with measurements. In addition to Monte Carlo calculations we also used existing treatment planning systems. The dose estimations of a number of patients and the derived risk per unit of dose, which is important for both radiotherapy as well as radiation protection in general, is discussed.

Factors that affect the accuracy in the precise radiotherapy for abdomen tumors

International Nuclear Information System (INIS)

Yang Tieming; Ju Yongjian

2008-01-01

The precise radiotherapy has been widely used in the clinics. But there are many factors that affect the accuracy in the course of implementation. Finally the effect of radiotherapy is affected. These factors are reviewed. And the previous research data about the abdomen tumors is summed up. Also how the accuracy was affected by the respiratory movement, positioning, position fixed technology, weight, retraction and motion of the tumor and the situation of surrounding organs will be analyzed. At last, how to avoid these errors in clinics will be discussed. (authors)

Hyperthermia and radiotherapy

International Nuclear Information System (INIS)

Fitspatrick, C.

1990-01-01

Hyperthermia and radiotherapy have for long been used to assist in the control of tumours, either as separate entities, or, in a combined treatment scheme. This paper outlines why hyperthermia works, thermal dose and the considerations required in the timing when hyperthermia is combined with radiotherapy. Previously reported results for hyperthermia and radiotherapy used together are also presented. 8 refs., 8 tabs

How PET is changing the management of cancer with radiotherapy

International Nuclear Information System (INIS)

Mac Manus, M.

2005-01-01

Information from PET scanning is transforming the management of many malignancies and the impact of PET is likely to increase further as new indications are recognised. PET is of particular value in patients treated with radiotherapy (RT) with curative intent. These patients rarely undergo invasive surgical staging and therefore imaging is crucial in determining the extent of disease before treatment. More accurate staging with PET means that futile aggressive RT or chcmoRT can be avoided in patients with incurable extensive disease. FDG-PET is of proven value in the staging of common metabolically-active malignancies treated with radiotherapy. These include lung cancer, head and neck cancer, lymphomas and oesophageal carcinoma. It has been shown that PET can improve the selection of patients for radical surgery or radiotherapy in lung cancer and that PET-based staging more accurately predicts survival than conventional staging. For those patients that remain eligible for definitive RT after PET. treatment can be more accurately targeted at the tumour and involved regional nodes. The value of PET for treatment planning is enhanced significantly when PET and CT scans are acquired on a combined PET/CT scanner. Fused PET-CT images can be imported into the radiotherapy planning computer and used to accurately target tumour with the best beam arrangement. After treatment, response may be hard to assess with structural imaging. PET-rcsponse to chemotherapy or radiotherapy in non-small cell lung cancer (NSCLC) predicts survival in NSCLC more accurately than CT response. However, PET has much more potential than imaging with FDG alone can realise. Markers such as FLT can be used to image proliferation in tumours, misonidazole or FAZA can be used to image hypoxia and labeled metabolites of anti-cancer drugs such as 5-FU can be used to study pharmacokinetics. New combinations of radiation and drugs may emerge that can be selected based on biological characteristics of

Radiotherapy

International Nuclear Information System (INIS)

Wannenmacher, M.; Debus, J.; Wenz, F.

2006-01-01

The book is focussed on the actual knowledge on the clinical radiotherapy and radio-oncology. Besides fundamental and general contributions specific organ systems are treated in detail. The book contains the following contributions: Basic principles, radiobiological fundamentals, physical background, radiation pathology, basics and technique of brachytherapy, methodology and technique of the stereotactic radiosurgery, whole-body irradiation, operative radiotherapy, hadron therapy, hpyerthermia, combined radio-chemo-therapy, biometric clinical studies, intensity modulated radiotherapy, side effects, oncological diagnostics; central nervous system and sense organs, head-neck carcinomas, breast cancer, thorax organs, esophagus carcinoma, stomach carcinoma, pancreas carcinoma, heptabiliary cancer and liver metastases, rectal carcinomas, kidney and urinary tract, prostate carcinoma, testicular carcinoma, female pelvis, lymphatic system carcinomas, soft tissue carcinoma, skin cancer, bone metastases, pediatric tumors, nonmalignant diseases, emergency in radio-oncology, supporting therapy, palliative therapy

Stereotactic radiotherapy in oligometastatic cancer.

Science.gov (United States)

Kennedy, Thomas A C; Corkum, Mark T; Louie, Alexander V

2017-09-01

Oligometastatic cancer describes a disease state somewhere between localized and metastatic cancer. Proposed definitions of oligometastatic disease have typically used a cut-off of five or fewer sites of disease. Treatment of oligometastatic disease should have the goal of long-term local control, and in selected cases, disease remission. While several retrospective cohorts argue for surgical excision of limited metastases (metastasectomy) as the preferred treatment option for several clinical indications, limited randomized data exists for treating oligometastases. Alternatively, stereotactic ablative radiotherapy (SABR) is a radiotherapy technique that combines high radiation doses per fraction with precision targeting with the goal of achieving long-term local control of treated sites. Published cohort studies of SABR have demonstrated excellent local control rates of 70-90% in oligometastatic disease, with long-term survival in some series approaching 20-40%. A recent randomized phase 2 clinical trial by Gomez et al. demonstrated significantly improved progression free survival with aggressive consolidative therapy (surgery, radiotherapy ± chemotherapy or SABR) in oli-gometastatic non-small cell lung cancer (NSCLC). As additional randomized controlled trials are ongoing to determine the efficacy of SABR in oligometastatic disease, SABR is increasingly being used within routine clinical practice. This review article aims to sum-marize the history and current paradigm of the oligometastatic state, review recently pub-lished literature of SABR in oligometastatic cancer and discuss ongoing trials and future directions in this context.

Clinical application of intensity and energy modulated radiotherapy with photon and electron beams

International Nuclear Information System (INIS)

Xiangkui Mu

2005-01-01

In modern, advanced radiotherapy (e.g. intensity modulated photon radiotherapy, IMXT) the delivery time for each fraction becomes prolonged to 10-20 minutes compared with the conventional, commonly 2-5 minutes. The biological effect of this prolongation is not fully known. The large number of beam directions in IMXT commonly leads to a large integral dose in the patient. Electrons would reduce the integral dose but are not suitable for treating deep-seated tumour, due to their limited penetration in tissues. By combining electron and photon beams, the dose distributions may be improved compared with either used alone. One obstacle for using electron beams in clinical routine is that there is no available treatment planning systems that optimise electron beam treatments in a similar way as for IMXT. Protons have an even more pronounced dose fall-off, larger penetration depth and less penumbra widening than electrons and are therefore more suitable for advanced radiotherapy. However, proton facilities optimised for advanced radiotherapy are not commonly available. In some instances electron beams may be an acceptable surrogate. The first part of this study is an experimental in vitro study where the situation in a tumour during fractionated radiotherapy is simulated. The effect of the prolonged fraction time is compared with the predictions by radiobiological models. The second part is a treatment planning study to analyse the mixing of electron and photon beams for at complex target volume in comparison with IMXT. In the next step a research version of an electron beam optimiser was used for the improvement of treatment plans. The aim was to develop a method for translating crude energy and intensity matrices for optimised electrons into a deliverable treatment plan without destroying the dose distribution. In the final part, different methods of treating the spinal canal in medulloblastoma were explored in a treatment planning study that was evaluated with

Role of Radiotherapy in Metastatic Non-small Cell Lung Cancer (NSCLC

Directory of Open Access Journals (Sweden)

Sergio L. Faria

2014-10-01

Full Text Available Radiotherapy has had important role in the palliation of NSCLC. Randomized trials tend to suggest that, in general, short regimens give similar palliation and toxicity compared to longer regimens. The benefit of combining chemotherapy to radiosensitize the palliative radiation treatment is an open question, but so far it has not been proved to be very useful in NSCLC. The addition of molecular targeted drugs to radiotherapy outside of approved regimens or clinical trials warrants careful consideration for every single case and probably should not be used as a routine management.Stereotactic radiosurgery (SRS and stereotactic body radiation therapy (SBRT are modern techniques being used each time more frequently in the treatment of single or oligometastases. In general, they offer good tumour control with little toxicity (with a more expensive cost compared to the traditionally fractionated radiotherapy regimens.

Radiotherapy fractionation for the palliation of uncomplicated painful bone metastases – an evidence-based practice guideline

International Nuclear Information System (INIS)

Wu, Jackson Sai-Yiu; Wong, Rebecca KS; Lloyd, Nancy S; Johnston, Mary; Bezjak, Andrea; Whelan, Timothy

2004-01-01

This practice guideline was developed to provide recommendations to clinicians in Ontario on the preferred standard radiotherapy fractionation schedule for the treatment of painful bone metastases. A systematic review and meta-analysis was performed and published elsewhere. The Supportive Care Guidelines Group, a multidisciplinary guideline development panel, formulated clinical recommendations based on their interpretation of the evidence. In addition to evidence from clinical trials, the panel also considered patient convenience and ease of administration of palliative radiotherapy. External review of the draft report by Ontario practitioners was obtained through a mailed survey, and final approval was obtained from the Practice Guidelines Coordinating Committee. Meta-analysis did not detect a significant difference in complete or overall pain relief between single treatment and multifraction palliative radiotherapy for bone metastases. Fifty-nine Ontario practitioners responded to the mailed survey (return rate 62%). Forty-two percent also returned written comments. Eighty-three percent of respondents agreed with the interpretation of the evidence and 75% agreed that the report should be approved as a practice guideline. Minor revisions were made based on feedback from the external reviewers and the Practice Guidelines Coordinating Committee. The Practice Guidelines Coordinating Committee approved the final practice guideline report. For adult patients with single or multiple radiographically confirmed bone metastases of any histology corresponding to painful areas in previously non-irradiated areas without pathologic fractures or spinal cord/cauda equine compression, we conclude that: • Where the treatment objective is pain relief, a single 8 Gy treatment, prescribed to the appropriate target volume, is recommended as the standard dose-fractionation schedule for the treatment of symptomatic and uncomplicated bone metastases. Several factors frequently

A strategy to correct for intrafraction target translation in conformal prostate radiotherapy: Simulation results

International Nuclear Information System (INIS)

Keall, P. J.; Lauve, A. D.; Hagan, M. P.; Siebers, J. V.

2007-01-01

A strategy is proposed in which intrafraction internal target translation is corrected for by repositioning the multileaf collimator position aperture to conform to the new target pose in the beam projection, and the beam monitor units are adjusted to account for the change in the geometric relationship between the target and the beam. The purpose of this study was to investigate the dosimetric stability of the prostate and critical structures in the presence of internal target translation using the dynamic compensation strategy. Twenty-five previously treated prostate cancer patients were replanned using a four-field conformal technique to deliver 72 Gy to 95% of the planning target volume (PTV). Internal translation was introduced by displacing the prostate PTV (no rotation or deformation was considered). Thirty-six randomly selected isotropic displacements of magnitude 0.5, 1.0, 1.5 and 2.0 cm were sampled for each patient, for a total of 3600 errors. Due to their anatomic relation to the prostate, the rectum and bladder contours were also moved with the same magnitude and direction as the prostate. The dynamic compensation strategy was used to correct each of these errors by conforming the beam apertures to the new target pose and adjusting the monitor units using inverse-square and off-axis factor corrections. The dynamic compensation strategy plans were then compared to the original treatment plans via dose-volume histogram (DVH) analysis. Changes of more than 5% of the prescription dose (3.6 Gy) were deemed clinically significant. Compared to the original treatment plans, the dynamic compensation strategy produced small discrepancies in isodose distributions and DVH analyses for all structures considered apart from the femoral heads. These differences increased with the magnitude of the internal motion. Coverage of the PTV was excellent: D 5 , D 95 , and D mean were not increased or decreased by more than 5% of the prescription dose for any of the 3600

Analysis of Electronic Densities and Integrated Doses in Multiform Glioblastomas Stereotactic Radiotherapy

International Nuclear Information System (INIS)

Baron-Aznar, C.; Moreno-Jimenez, S.; Celis, M. A.; Ballesteros-Zebadua, P.; Larraga-Gutierrez, J. M.

2008-01-01

Integrated dose is the total energy delivered in a radiotherapy target. This physical parameter could be a predictor for complications such as brain edema and radionecrosis after stereotactic radiotherapy treatments for brain tumors. Integrated Dose depends on the tissue density and volume. Using CT patients images from the National Institute of Neurology and Neurosurgery and BrainScan(c) software, this work presents the mean density of 21 multiform glioblastomas, comparative results for normal tissue and estimated integrated dose for each case. The relationship between integrated dose and the probability of complications is discussed

Present and future of the Image Guided Radiotherapy (I.G.R.T.) and its applications in lung cancer treatment

International Nuclear Information System (INIS)

Lefkopoulos, D.; Ferreira, I.; Isambert, A.; Le Pechoux, C.; Mornex, F.

2007-01-01

These last years, the new irradiation techniques as the conformal 3D radiotherapy and the IMRT are strongly correlated with the technological developments in radiotherapy. The rigorous definition of the target volume and the organs at risk required by these irradiation techniques, imposed the development of various image guided patient positioning and target tracking techniques. The availability of these imaging systems inside the treatment room has lead to the exploration of performing real-time adaptive radiation therapy. In this paper we present the different image guided radiotherapy (IGRT) techniques and the adaptive radiotherapy (ART) approaches. IGRT developments are focused in the following areas: 1) biological imaging for better definition of tumor volume; 2) 4D imaging for modeling the intra-fraction organ motion; 3) on-board imaging system or imaging devices registered to the treatment machines for inter-fraction patient localization; and 4) treatment planning and delivery schemes incorporating the information derived from the new imaging techniques. As this paper is included in the 'Cancer Radiotherapie' special volume dedicated to the lung cancers, in the description of the different IGRT techniques we try to present the lung tumors applications when this is possible. (author)

Suicide genes or p53 gene and p53 target genes as targets for cancer gene therapy by ionizing radiation

International Nuclear Information System (INIS)

Liu Bing; Chinese Academy of Sciences, Beijing; Zhang Hong

2005-01-01

Radiotherapy has some disadvantages due to the severe side-effect on the normal tissues at a curative dose of ionizing radiation (IR). Similarly, as a new developing approach, gene therapy also has some disadvantages, such as lack of specificity for tumors, limited expression of therapeutic gene, potential biological risk. To certain extent, above problems would be solved by the suicide genes or p53 gene and its target genes therapies targeted by ionizing radiation. This strategy not only makes up the disadvantage from radiotherapy or gene therapy alone, but also promotes success rate on the base of lower dose. By present, there have been several vectors measuring up to be reaching clinical trials. This review focused on the development of the cancer gene therapy through suicide genes or p53 and its target genes mediated by IR. (authors)

Feasibility of preference-driven radiotherapy dose treatment planning to support shared decision making in anal cancer

DEFF Research Database (Denmark)

Rønde, Heidi S; Wee, Leonard; Pløen, John

2017-01-01

PURPOSE/OBJECTIVE: Chemo-radiotherapy is an established primary curative treatment for anal cancer, but clinically equal rationale for different target doses exists. If joint preferences (physician and patient) are used to determine acceptable tradeoffs in radiotherapy treatment planning, multipl...... that preference-informed dose planning is feasible for clinical studies utilizing shared decision making....... dose plans must be simultaneously explored. We quantified the degree to which different toxicity priorities might be incorporated into treatment plan selection, to elucidate the feasible decision space for shared decision making in anal cancer radiotherapy. MATERIAL AND METHODS: Retrospective plans.......7%-points; (0.3; 30.6); p decision space available in anal cancer radiotherapy to incorporate preferences, although tradeoffs are highly patient-dependent. This study demonstrates...

Therapeutic Results of Radiotherapy in Rectal Carcinoma -Comparison of Sandwich Technique Radiotherapy with Postoperative Radiotherapy

International Nuclear Information System (INIS)

Huh, Gil Cha; Suh, Hyun Suk; Lee, Hyuk Sang; Kim, Re Hwe; Kim, Chul Soo; Kim, Hong Yong; Kim, Sung Rok

1996-01-01

Purpose : To evaluate the potential advantage for 'sandwich' technique radiotherapy compared to postoperative radiotherapy in respectable rectal cancer. Between January 1989 and May 1994, 60 patients with respectable rectal cancer were treated at Inje University Seoul and Sanggye Paik Hospital.Fifty one patients were available for analysis : 20 patients were treated with sandwich technique radiotherapy and 31 patients were treated with postoperative radiotherapy. In sandwich technique radiotherapy(RT), patients were treated with preoperative RT 1500 cGy/5fx followed by immediate curative resection. Patients staged as Astler-Coller B2, C were considered for postoperative RT with 2500-4500 cGy. In postoperative RT, total radiation dose of 4500-6120 cGy, 180 cGy daily at 4-6 weeks was delivered. Patients were followed for median period of 25 months. Results : The overall 5-year survival rates for sandwich technique RT group and postoperative RT group were 60% and 71%, respectively(p>0.05). The 5-year disease free survival rates for each group were 63%. There was no difference in local failure rate between two groups(11% versus 7%). Incidence of distant metastasis was 11%(2/20) in the sandwich technique RT group and 20%(6/31) in the postoperative RT group(p>0.05). The frequencies of acute and chronic complications were comparable in both groups. Conclusion : The sandwich technique radiotherapy group shows local recurrence and survival similar to those of postoperative RT alone group but reduced distant metastasis compared to postoperative RT group. But long term follow-up and large number of patients is needed to make an any firm conclusion regarding the value of this sandwich technique RT

Bladder radiotherapy treatment: A retrospective comparison of 3-dimensional conformal radiotherapy, intensity-modulated radiation therapy, and volumetric-modulated arc therapy plans

Energy Technology Data Exchange (ETDEWEB)

Pasciuti, Katia, E-mail: k.pasciuti@virgilio.it [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Kuthpady, Shrinivas [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom); Anderson, Anne; Best, Bronagh [Department of Radiotherapy Physics, Royal Free Hospital, London (United Kingdom); Waqar, Saleem; Chowdhury, Subhra [Department of Radiotherapy, Royal Free Hospital, London (United Kingdom)

2017-04-01

To examine tumor's and organ's response when different radiotherapy plan techniques are used. Ten patients with confirmed bladder tumors were first treated using 3-dimensional conformal radiotherapy (3DCRT) and subsequently the original plans were re-optimized using the intensity-modulated radiation treatment (IMRT) and volumetric-modulated arc therapy (VMAT)-techniques. Targets coverage in terms of conformity and homogeneity index, TCP, and organs' dose limits, including integral dose analysis were evaluated. In addition, MUs and treatment delivery times were compared. Better minimum target coverage (1.3%) was observed in VMAT plans when compared to 3DCRT and IMRT ones confirmed by a statistically significant conformity index (CI) results. Large differences were observed among techniques in integral dose results of the femoral heads. Even if no statistically significant differences were reported in rectum and tissue, a large amount of energy deposition was observed in 3DCRT plans. In any case, VMAT plans provided better organs and tissue sparing confirmed also by the normal tissue complication probability (NTCP) analysis as well as a better tumor control probability (TCP) result. Our analysis showed better overall results in planning using VMAT techniques. Furthermore, a total time reduction in treatment observed among techniques including gantry and collimator rotation could encourage using the more recent one, reducing target movements and patient discomfort.

Conventional and conformal technique of external beam radiotherapy in locally advanced cervical cancer: Dose distribution, tumor response, and side effects

Science.gov (United States)

Mutrikah, N.; Winarno, H.; Amalia, T.; Djakaria, M.

2017-08-01

The objective of this study was to compare conventional and conformal techniques of external beam radiotherapy (EBRT) in terms of the dose distribution, tumor response, and side effects in the treatment of locally advanced cervical cancer patients. A retrospective cohort study was conducted on cervical cancer patients who underwent EBRT before brachytherapy in the Radiotherapy Department of Cipto Mangunkusumo Hospital. The prescribed dose distribution, tumor response, and acute side effects of EBRT using conventional and conformal techniques were investigated. In total, 51 patients who underwent EBRT using conventional techniques (25 cases using Cobalt-60 and 26 cases using a linear accelerator (LINAC)) and 29 patients who underwent EBRT using conformal techniques were included in the study. The distribution of the prescribed dose in the target had an impact on the patient’s final response to EBRT. The complete response rate of patients to conformal techniques was significantly greater (58%) than that of patients to conventional techniques (42%). No severe acute local side effects were seen in any of the patients (Radiation Therapy Oncology Group (RTOG) grades 3-4). The distribution of the dose and volume to the gastrointestinal tract affected the proportion of mild acute side effects (RTOG grades 1-2). The urinary bladder was significantly greater using conventional techniques (Cobalt-60/LINAC) than using conformal techniques at 72% and 78% compared to 28% and 22%, respectively. The use of conformal techniques in pelvic radiation therapy is suggested in radiotherapy centers with CT simulators and 3D Radiotherapy Treatment Planning Systems (RTPSs) to decrease some uncertainties in radiotherapy planning. The use of AP/PA pelvic radiation techniques with Cobalt-60 should be limited in body thicknesses equal to or less than 18 cm. When using conformal techniques, delineation should be applied in the small bowel, as it is considered a critical organ according to RTOG

Postoperative Irradiation of Gynecologic Malignancies: Improving Treatment Delivery Using Aperture-Based Intensity-Modulated Radiotherapy

International Nuclear Information System (INIS)

Nadeau, Sylvain; Bouchard, Myriam; Germain, Isabelle; Raymond, Paul-Emile; Beaulieu, Frederic; Beaulieu, Luc; Roy, Rene; Gingras, Luc

2007-01-01

Purpose: To evaluate dosimetric and treatment delivery advantages of aperture-based intensity-modulated radiotherapy (AB-IMRT) for the treatment of patients receiving whole pelvic radiotherapy for gynecologic malignancies. Methods and Materials: Nineteen patients undergoing pelvic radiotherapy after resection of endometrial cancers were selected. A 45-Gy dose was prescribed to the target volume delineated on a planning CT scan. An in-house inverse planning system, Ballista, was used to develop a treatment plan using aperture-based multileaf collimator segments. This approach was compared with conventional four-field, enlarged four-field, and static beamlet-based IMRT (BB-IMRT) techniques in terms of target coverage, dose-volume histogram statistics for surrounding normal tissues, and numbers of segments and monitor units (MU). Results: Three quarters (76.4%) of the planning target volume received the prescription dose with conventional four-field plans. With adequate target coverage, the Ballista plans significantly reduced the volume of bowel and bladder irradiated at the prescribed dose (p < 0.001), whereas the two approaches provided equivalent results for the rectum (p 0.5). On the other hand, AB-IMRT and BB-IMRT plans showed only small differences in dose-volume histogram statistics of unknown clinical impact, whereas Ballista plan delivery required on average 73% and 59% fewer segments and MU, respectively. Conclusion: With respect to conventional techniques, AB-IMRT for the treatment of gynecologic malignancies provides dosimetric advantages similar to those with BB-IMRT but with clear treatment delivery improvements

Intracavitary curietherapy of nasopharyngeal cancer after external radiotherapy

International Nuclear Information System (INIS)

Latini, P.; Panizza, B.M.; Checcaglini, F.; Maranzano, E.; Aristei, C.; Perucci, E.

1991-01-01

The authors report their experience in the treatment of nasopharyngeal carcinoma with intracavitary curietherapy to cure small recurring carcinomas or residual local disease 2-6 weeks after completing external radiotherapy. Since 1984 , 10 patients have received intracavitary radiotherapy with customized molds charged with Ir 192. Six of them received a boost dose because of residual disease and for local recurrence. The technique we employed to shape the molds is described, together with the mode of use and the doses to target volume. Due to both the small number of treated cases and the short follow-up, no significant conclusions could be drawn relative to survival time. However, it must be stressed that this therapeutic approach gives a high local control rate with no severe side-effects or sequelae

Cyberknife : how has it changed the radiotherapy practice?

International Nuclear Information System (INIS)

Hukku, S.

2016-01-01

The CyberKnife is a frameless robotic radiosurgery system used for treating benign tumors, malignant tumors and other medical conditions. The system was invented by John R. Adler, a Stanford University professor of neurosurgery and radiation oncology, and Peter and Russell Schonberg of Schonberg Research Corporation. It is the most accurate and flexible tool available for aggressive therapeutic irradiation. It is a method of delivering radiotherapy, with the intention of targeting treatment more accurately than standard radiotherapy. The two main elements of the CyberKnife are: 1. The radiation produced from a small linear particle accelerator (linac) 2. A robotic arm which allows the energy to be directed at any part of the body from any direction. Several generations of the CyberKnife system have been developed since its initial inception in 1990

Commissioning an image-guided localization system for radiotherapy

International Nuclear Information System (INIS)

Phillips, Mark H.; Singer, Karen; Miller, Elizabeth; Stelzer, Keith

2000-01-01

Purpose: To describe the design and commissioning of a system for the treatment of classes of tumors that require highly accurate target localization during a course of fractionated external-beam therapy. This system uses image-guided localization techniques in the linac vault to position patients being treated for cranial tumors using stereotactic radiotherapy, conformal radiotherapy, and intensity-modulated radiation therapy techniques. Design constraints included flexibility in the use of treatment-planning software, accuracy and precision of repeat localization, limits on the time and human resources needed to use the system, and ease of use. Methods and Materials: A commercially marketed, stereotactic radiotherapy system, based on a system designed at the University of Florida, Gainesville, was adapted for use at the University of Washington Medical Center. A stereo pair of cameras in the linac vault were used to detect the position and orientation of an array of fiducial markers that are attached to a patient's biteblock. The system was modified to allow the use of either a treatment-planning system designed for stereotactic treatments, or a general, three-dimensional radiation therapy planning program. Measurements of the precision and accuracy of the target localization, dose delivery, and patient positioning were made using a number of different jigs and devices. Procedures were developed for the safe and accurate clinical use of the system. Results: The accuracy of the target localization is comparable to that of other treatment-planning systems. Gantry sag, which cannot be improved, was measured to be 1.7 mm, which had the effect of broadening the dose distribution, as confirmed by a comparison of measurement and calculation. The accuracy of positioning a target point in the radiation field was 1.0 ± 0.2 mm. The calibration procedure using the room-based lasers had an accuracy of 0.76 mm, and using a floor-based radiosurgery system it was 0.73 mm

Dose calculation system for remotely supporting radiotherapy

International Nuclear Information System (INIS)

Saito, K.; Kunieda, E.; Narita, Y.; Kimura, H.; Hirai, M.; Deloar, H. M.; Kaneko, K.; Ozaki, M.; Fujisaki, T.; Myojoyama, A.; Saitoh, H.

2005-01-01

The dose calculation system IMAGINE is being developed keeping in mind remotely supporting external radiation therapy using photon beams. The system is expected to provide an accurate picture of the dose distribution in a patient body, using a Monte Carlo calculation that employs precise models of the patient body and irradiation head. The dose calculation will be performed utilising super-parallel computing at the dose calculation centre, which is equipped with the ITBL computer, and the calculated results will be transferred through a network. The system is intended to support the quality assurance of current, widely carried out radiotherapy and, further, to promote the prevalence of advanced radiotherapy. Prototypes of the modules constituting the system have already been constructed and used to obtain basic data that are necessary in order to decide on the concrete design of the system. The final system will be completed in 2007. (authors)

Intensity-modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy for high-grade gliomas: Does IMRT increase the integral dose to normal brain?

International Nuclear Information System (INIS)

Hermanto, Ulrich; Frija, Erik K.; Lii, MingFwu J.; Chang, Eric L.; Mahajan, Anita; Woo, Shiao Y.

2007-01-01

Purpose: To determine whether intensity-modulated radiotherapy (IMRT) treatment increases the total integral dose of nontarget tissue relative to the conventional three-dimensional conformal radiotherapy (3D-CRT) technique for high-grade gliomas. Methods and Materials: Twenty patients treated with 3D-CRT for glioblastoma multiforme were selected for a comparative dosimetric evaluation with IMRT. Original target volumes, organs at risk (OAR), and dose-volume constraints were used for replanning with IMRT. Predicted isodose distributions, cumulative dose-volume histograms of target volumes and OAR, normal tissue integral dose, target coverage, dose conformity, and normal tissue sparing with 3D-CRT and IMRT planning were compared. Statistical analyses were performed to determine differences. Results: In all 20 patients, IMRT maintained equivalent target coverage, improved target conformity (conformity index [CI] 95% 1.52 vs. 1.38, p mean by 19.8% and D max by 10.7%), optic chiasm (D mean by 25.3% and D max by 22.6%), right optic nerve (D mean by 37.3% and D max by 28.5%), and left optic nerve (D mean by 40.6% and D max by 36.7%), p ≤ 0.01. This was achieved without increasing the total nontarget integral dose by greater than 0.5%. Overall, total integral dose was reduced by 7-10% with IMRT, p < 0.001, without significantly increasing the 0.5-5 Gy low-dose volume. Conclusions: These results indicate that IMRT treatment for high-grade gliomas allows for improved target conformity, better critical tissue sparing, and importantly does so without increasing integral dose and the volume of normal tissue exposed to low doses of radiation

Three-dimensional intrafractional internal target motions in accelerated partial breast irradiation using three-dimensional conformal external beam radiotherapy.

Science.gov (United States)

Hirata, Kimiko; Yoshimura, Michio; Mukumoto, Nobutaka; Nakamura, Mitsuhiro; Inoue, Minoru; Sasaki, Makoto; Fujimoto, Takahiro; Yano, Shinsuke; Nakata, Manabu; Mizowaki, Takashi; Hiraoka, Masahiro

2017-07-01

We evaluated three-dimensional intrafractional target motion, divided into respiratory-induced motion and baseline drift, in accelerated partial breast irradiation (APBI). Paired fluoroscopic images were acquired simultaneously using orthogonal kV X-ray imaging systems at pre- and post-treatment for 23 patients who underwent APBI with external beam radiotherapy. The internal target motion was calculated from the surgical clips placed around the tumour cavity. The peak-to-peak respiratory-induced motions ranged from 0.6 to 1.5mm in all directions. A systematic baseline drift of 1.5mm towards the posterior direction and a random baseline drift of 0.3mm in the lateral-medial and cranial-caudal directions were observed. The baseline for an outer tumour cavity drifted towards the lateral and posterior directions, and that for an upper tumour cavity drifted towards the cranial direction. Moderate correlations were observed between the posterior baseline drift and the patients' physical characteristics. The posterior margin for intrafractional uncertainties was larger than 5mm in patients with greater fat thickness due to the baseline drift. The magnitude of the intrafractional motion was not uniform according to the direction, patients' physical characteristics, or tumour cavity location due to the baseline drift. Therefore, the intrafractional systematic movement should be properly managed. Copyright © 2017 Elsevier B.V. All rights reserved.

Markov chain Monte Carlo methods in radiotherapy treatment planning

International Nuclear Information System (INIS)

Hugtenburg, R.P.

2001-01-01

The Markov chain method can be used to incorporate measured data in Monte Carlo based radiotherapy treatment planning. This paper shows that convergence to the measured data, within the target precision, is achievable. Relative output factors for blocked fields and oblique beams are shown to compare well with independent measurements according to the same criterion. (orig.)

Historical review of radiotherapy

International Nuclear Information System (INIS)

Onai, Yoshio

1993-01-01

The techniques of radiotherapy have been improved by development of particle accelerators, radionuclides and computers. This paper presents a historical review of the physical and technical aspects of radiotherapy in Japan. Changes in the kinds of radiation, such as X-rays, gamma rays, electrons, neutrons and protons used for external radiotherapy, and the equipment involved are described chronologically, and historical changes in the quality of radiotherapy apparatus are outlined. Patient data acquisition equipment, such as X-ray simulator and X-ray CT, beam modifying devices, patient setup devices, and devices to verify treatment fields and patient doses are reviewed historically. Radiation sources for brachytherapy and internal radiotherapy, and remotely controlled afterloading systems are reviewed chronologically. Historical changes in methods to evaluate absorbed doses, dose monitor systems and beam data acquisition systems are outlined. Changes in methods of calculating dose distributions for external X-ray and electron therapy, brachytherapy and internal radiotherapy by unsealded radionuclides are described and calculation techniques for treatment planning system are reviewed. Annual figures in the numbers of radiotherapy equipment, such as telecobalt and telecesium units, linear accelerators, betatrons, microtrons, stereotactic gamma units, conformation radiotherapy units, remotely controlled afterloading systems, and associated equipment such as X-ray simulators and treatment planning systems are provided, as are changes in the number of accelerators by maximum X-ray energy and maximum electron energy, and in the number of licensed hospitals and clinics using small sealed sources. Changes in techniques of external radiotherapy and brachytherapy are described briefly from the point of view of dose distributions. (author)

Clinical application of radiation dosimetry on X-ray radiotherapy

International Nuclear Information System (INIS)

Mizutani, Takeo

1995-01-01

In the case of radiotherapy, it is important to give proper dose for a tumor, to be treated with the objective of therapy, and to evaluate the dose, considering dose for other organs at risk to a sufficient extent. To provide an exposure dose at the target volume of tumor parts, it should be required to get a good understanding of the correct dosimetric method and also to apply this to clinical application in practice. All over the country, so as not to produce any difference in the given dose, 'A practical code for the dosimetry of high energy X-rays in radiotherapy' was issued by the Japanese Associations of radiological physicists in 1972. In 1986, it was revised. At about 85% of therapeutic facilities in the country, radiation engineers perform dose measurements and controls. Therefore, I have explained the process of measurement and dose calculation, with the main objective directed at the engineers in charge of the radiotherapy so as to easily radiation dosimetry of X-ray with dosemeters and phantom used at each facility according to the 'practical code'. (author)

Clinical evaluation of radiotherapy for endocrine ophthalmopathy

International Nuclear Information System (INIS)

Okada, Kayoko; Oshitani, Takashi; Mieda, Chieko

1990-01-01

Ten patients with severe endocrine ophthalmopathy were treated by radiotherapy at Hyogo Medical Center for Adults from May 1984 to February 1988. All but one of the patients had poorly responded to previous systemic or topical corticosteroid therapy. The target of the radiotherapy was both retrobulbar tissues. The radiation field used was about 4 x 4 cm, excluding the pituitary gland and the brain, and was angled 5deg posteriorly to avoid the contralateral lens. A total of 2000 cGy was given to each patient over a 2 week-period. Eight of the ten patients showed some response, with 5 of them (50%) having a good to excellent response. Treatment was more effective for soft tissue changes, proptosis and keratopathy, while myopathy was less responsive. As for the duration of the eye signs and symptoms, those of a shorter duration (less than 12 months) responded better. It was also noted that the degree of the eye muscle enlargement on the pre-treatment orbital CT scan was directly correlated to the results of the treatment. Although three of the patients experienced transient headache, there were no serious acute reactions or long term complications. In conclusion, retrobulbar radiotherapy is a well-tolerated, safe and effective treatment for sever endocrine ophthalmopathy. (author)

Clinical evaluation of radiotherapy for endocrine ophthalmopathy

Energy Technology Data Exchange (ETDEWEB)

Okada, Kayoko; Oshitani, Takashi; Mieda, Chieko (Hyogo Medical Center for Adults, Hyogo (Japan)) (and others)

1990-06-01

Ten patients with severe endocrine ophthalmopathy were treated by radiotherapy at Hyogo Medical Center for Adults from May 1984 to February 1988. All but one of the patients had poorly responded to previous systemic or topical corticosteroid therapy. The target of the radiotherapy was both retrobulbar tissues. The radiation field used was about 4 x 4 cm, excluding the pituitary gland and the brain, and was angled 5deg posteriorly to avoid the contralateral lens. A total of 2000 cGy was given to each patient over a 2 week-period. Eight of the ten patients showed some response, with 5 of them (50%) having a good to excellent response. Treatment was more effective for soft tissue changes, proptosis and keratopathy, while myopathy was less responsive. As for the duration of the eye signs and symptoms, those of a shorter duration (less than 12 months) responded better. It was also noted that the degree of the eye muscle enlargement on the pre-treatment orbital CT scan was directly correlated to the results of the treatment. Although three of the patients experienced transient headache, there were no serious acute reactions or long term complications. In conclusion, retrobulbar radiotherapy is a well-tolerated, safe and effective treatment for sever endocrine ophthalmopathy. (author).

Field arrangement and dosimetry verification for concave target

International Nuclear Information System (INIS)

Chen Liang; Wang Huankun; Li Yumin

2005-01-01

Objective: To provide a method of radiotherapy field arrangement for concave paraspinal target. Methods: Plan was designed for concave target in wax phantom and the selected patients by the guidance of beam eye view (BEV) provided by a 3D treatment planning system (CREAT EXPERT). In BEV, the inner border of all tangential fields was 2 mm out of the organ at risk (OAR) and the outer border was 5 mm beyond the target. Dosimetry films and ion chamber were used to verify the dose distribution and point dose in the wax phantom. Results: Dose distribution in phantom and patient was homogeneous. The mean dose of OAR in phantom did not exceed 16% of the prescribed dose. Isodose curves dropped more than 8% per mm between the target and OAR in the phantom. Film dosimetry coincided well with the calculated results. Position error in high dose region was with- in 4 mm and absolute dose errors were no more than 5%. Conclusion: Tangential field arrangement is valuable and practical in radiotherapy for concave paraspinal targets. (authors)

Role of radiotherapy in the treatment of meningiomas

International Nuclear Information System (INIS)

Noel, G.; Renard, A.; Mazeron, J.J.; Valery, C.; Mokhtari, K.

2001-01-01

Role of radiotherapy in the treatment of meningiomas. Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively. (authors)

Doses to organs and tissues from concomitant imaging in radiotherapy: a suggested framework for clinical justification.

Science.gov (United States)

Harrison, R M

2008-12-01

The increasing use of imaging for localization and verification in radiotherapy has raised issues concerning the justifiable doses to critical organs and tissues from concomitant exposures, particularly when extensive image-guided radiotherapy is indicated. Doses at positions remote from the target volume include components from high-energy leakage and scatter, as well as from concomitant imaging. In this paper, simulated prostate, breast and larynx treatments are used to compare doses from both high-energy and concomitant exposures as a function of distance from the target volume. It is suggested that the fraction, R, of the total dose at any point within the patient that is attributable to concomitant exposures may be a useful aid in their justification. R is small within the target volume and at large distances from it. However, there is a critical region immediately adjacent to the planning target volume where the dose from concomitant imaging combines with leakage and scatter to give values of R that approach 0.5 in the examples given here. This is noteworthy because the regions just outside the target volume will receive total doses in the order of 1 Gy, where commensurately high risk factors may not be substantially reduced because of cell kill. Other studies have identified these regions as sites of second cancers. The justification of an imaging regimen might therefore usefully take into account the maximum value of R encountered from the combination of imaging and radiotherapy for particular treatment sites.

Guidelines for equipment and staffing of radiotherapy facilities in the European countries: Final results of the ESTRO-HERO survey

DEFF Research Database (Denmark)

Dunscombe, Peter; Grau, Cai; Defourny, Noémie

2014-01-01

of guidelines for equipment and staffing and selected operational issues. Twenty-nine countries provided full or partial evaluable responses. RESULTS: The availability of guidelines across Europe is far from uniform. The metrics used for capital and human resources are variable. There seem to have been no major...... guidelines suggesting developments in clinical radiotherapy are moving faster than guideline updating. CONCLUSION: The efficient provision of safe, high quality radiotherapy services would benefit from the availability of well-structured guidelines for capital and human resources, based on agreed upon...

Physics aspects of recent and future concepts in radiotherapy

International Nuclear Information System (INIS)

Georg, D.

2001-01-01

Full text: The development of 3-D conformal radiotherapy (3D-CRT), in which the high dose volume matches as closely as possible the target volume and avoids therefore normal tissue irradiation as far as possible, has been a major theme in radiotherapy for improving the therapeutic window. Conformal radiotherapy is not a new concept but only the technological improvements of the last decade allow its clinical implementation. More recent and advanced forms of 3D-CRT are intensity modulated radiotherapy (IMRT) and stereotactic radiotherapy (SRT). IMRT uses an additional degree of freedom to achieve a new class of conformation: the variation of the primary beam intensity. SRT is based on a three dimensional stereotactic coordinate system which is correlated with the patient and the treatment facility through modern imaging technology. IMRT and SRT are related by common features, e.g. high dose gradients and small fields which require a high geometric precision. A high dosimetric and geometric precision can only be based on a detailed knowledge of the patient specific anatomy. Therefore, IMRT and SRT need to underlie multi-modality imaging studies. Both IMRT and SRT utilize photon beams and multiple field arrangements which increase the volumes of healthy tissue receiving low doses. Photons have a low selectivity along the beam direction implying that the sharp dose gradients are to be compromised. The increased low dose volume as well as the low selectivity of photon beams can be over-come by using proton or ions. Brachytherapy, a form of radiotherapy where encapsuled radioactive sources are placed directly in or in the vicinity of the tumor, is by definition conformal. Endovascular brachytherapy has become a promising new field in radiotherapy for the prevention of (re)stenosis after angioplasty. Although many clinical trials have been performed during the last years specific aspects related to endovascular brachytherapy have not been addressed clearly, such as the

Contact radiotherapy. Report of technological assessment

International Nuclear Information System (INIS)

Ortholan, Cecile; Melin, Nicole; Lee-Robin, Sun Hae; David, Denis Jean; Pages, Frederique; Devaud, Christine; Noel, Georges; Biga, Julie; Moty-Monnereau, Celine; Canet, Philippe; Lascols, Sylvie; Lamas, Muriel; Ramdine, Jessica; Tuil, Louise

2008-10-01

This report aims at assessing safety, indications, the role in therapeutic strategy, and efficiency of contact radiotherapy. It also aims at answering questions like: is the contact radiotherapy technique validated? What are the indications for contact radiotherapy? What about the efficiency and safety of contact radiotherapy? After a presentation of preliminary notions on radiotherapy (radiation types, dose, and irradiation techniques), the report presents this specific technique of contact radiotherapy: definition, devices, use recommendations, issues of radiation protection, modalities of performance of a contact radiotherapy session, and concerned pathologies. Then, based on a literature survey, this report addresses the various concerned tumours (skin, rectum, brain, breast), indicates some general information about these tumours (epidemiological data, anatomy and classification, therapeutic options, radiotherapy), and proposes an assessment of the efficiency and safety of contact radiotherapy

Primary lung sarcoma treated with stereotactic ablative radiotherapy: a case report

Directory of Open Access Journals (Sweden)

Yeo SG

2017-07-01

Full Text Available Seung-Gu Yeo Department of Radiation Oncology, Soonchunhyang University College of Medicine, Soonchunhyang University Hospital, Cheonan, Republic of Korea Abstract: Primary lung sarcoma (PLS is an extremely rare, very aggressive malignancy. Surgical removal is considered the treatment of choice, and patients who have been given conventional radiotherapy have had inferior outcomes. This study is the first describing a case of PLS treated with stereotactic ablative radiotherapy (SABR, which precisely targets a small tumor with a markedly higher biologically effective dose than conventional radiotherapy. The patient was an 82-year-old man who was diagnosed with primary lung leiomyosarcoma based on radiology, pathology, and immunohistochemical examinations. The PLS was located in the right lower lobe and measured 2.5 cm. No regional nodal or distant organ metastasis was observed. He was inoperable medically. The SABR was performed using volumetric modulated arc therapy and a dose of 56 Gy in four fractions. Follow-up computed tomography 2 months after SABR revealed a complete tumor response. The toxicity was limited to mild respiratory symptoms. The patient is alive and has had no evidence of disease for 2 years. This study suggests that SABR can be a safe and effective treatment option for PLS. Keywords: primary lung sarcoma, leiomyosarcoma, stereotactic ablative radiotherapy, stereotactic body radiotherapy, radiation therapy, sarcoma 

Tumor control and normal tissue toxicity: The two faces of radiotherapy

NARCIS (Netherlands)

van Oorschot, B.

2016-01-01

This thesis discusses the two contrasting sides of radiotherapy: tumor control and normal tissue toxicity. On one hand, radiation treatment aims to target the tumor with the highest possible radiation dose, inducing as much lethal DNA damage as possible. On the other hand however, escalation of the

Accelerated hyperfractionated radiotherapy for malignant gliomas

International Nuclear Information System (INIS)

Buatti, John M.; Marcus, Robert B.; Mendenhall, William M.; Friedman, William A.; Bova, Francis J.

1996-01-01

Purpose: To evaluate accelerated hyperfractionated radiotherapy for the treatment of malignant gliomas. Methods and Materials: Between April 1985 and June 1994, 70 adult patients with pathologically confirmed malignant glioma (75% glioblastoma multiforme, 25% anaplastic astrocytoma) suitable for high-dose therapy were selected for treatment with accelerated hyperfractionated radiotherapy, 1.5 Gy twice daily to a total target dose of 60 Gy. Two patients were excluded from analysis (one patient had a fatal pulmonary embolism after 18 Gy; one patient discontinued therapy after 28.5 Gy against medical advice and without sequelae or progression). The 68 patients in the study group had a median age of 52 years and a median Karnofsky performance status of 90. Stereotactic implant ( 125 I) or stereotactic radiosurgery boosts were delivered to 16 patients (24%) in the study group. Minimum follow-up was 6 months. Results: Median survival was 13.8 months and median progression-free survival was 7.4 months. The absolute Kaplan-Meier survival rate was 16% at 2 years and 4% at 5 years. Multivariate analysis for the prognostic impact of age, gender, histology, Karnofsky performance status, symptomatology, surgical resection vs. biopsy, and boost vs nonboost therapy revealed that Karnofsky performance status ≥ 90, boost therapy, and surgical excision predicted significantly improved outcome. No severe toxicity occurred in patients treated with accelerated hyperfractionated radiotherapy alone, although 5% required steroids temporarily for edema. Progression occurred during treatment in one patient (1.5%). Conclusion: This regimen of accelerated hyperfractionated radiotherapy is well tolerated and leads to results comparable with those of standard therapy. The rate of disease progression during treatment is significantly better (p = 0.001) than is reported for patients treated with standard fractionation, with or without chemotherapy. This regimen is a reasonable starting point

Transition from 2-D radiotherapy to 3-D conformal and intensity modulated radiotherapy

International Nuclear Information System (INIS)

2008-05-01

Cancer is one of the leading causes of death globally and radiotherapy is currently an essential component in the management of cancer patients, either alone or in combination with surgery or chemotherapy, both for cure or palliation. It is now recognized that safe and effective radiotherapy service needs not only substantial capital investment in radiotherapy equipment and specially designed facilities but also continuous investment in maintenance and upgrading of the equipment to comply with the technical progress, but also in training the staff. The recent IAEA-TECDOC publication 'Setting up a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects' provides general guidelines for designing and implementing radiotherapy services in Member States. Advances in computer technology have enabled the possibility of transitioning from basic 2- dimensional treatment planning and delivery (2-D radiotherapy) to a more sophisticated approach with 3-dimensional conformal radiotherapy (3-D CRT). Whereas 2-D radiotherapy can be applied with simple equipment, infrastructure and training, transfer to 3-D conformal treatments requires more resources in technology, equipment, staff and training. A novel radiation treatment approach using Intensity Modulated Radiation Therapy (IMRT) that optimizes the delivery of radiation to irregularly shaped tumour volumes demands even more sophisticated equipment and seamless teamwork, and consequentially more resources, advanced training and more time for treatment planning and verification of dose delivery than 3-D CRT. Whereas 3-D CRT can be considered as a standard, IMRT is still evolving. Due to the increased interest of Member States to the modern application of radiotherapy the IAEA has received a number of requests for guidance coming from radiotherapy departments that wish to upgrade their facilities to 3-D CRT and IMRT through Technical Cooperation programme. These requests are expected to increase

Anatomical imaging for radiotherapy

International Nuclear Information System (INIS)

Evans, Philip M

2008-01-01

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

FDG-PET/CT imaging for staging and target volume delineation in conformal radiotherapy of anal carcinoma

International Nuclear Information System (INIS)

Krengli, Marco; Inglese, Eugenio; Milia, Maria E; Turri, Lucia; Mones, Eleonora; Bassi, Maria C; Cannillo, Barbara; Deantonio, Letizia; Sacchetti, Gianmauro; Brambilla, Marco

2010-01-01

FDG-PET/CT imaging has an emerging role in staging and treatment planning of various tumor locations and a number of literature studies show that also the carcinoma of the anal canal may benefit from this diagnostic approach. We analyzed the potential impact of FDG-PET/CT in stage definition and target volume delineation of patients affected by carcinoma of the anal canal and candidates for curative radiotherapy. Twenty seven patients with biopsy proven anal carcinoma were enrolled. Pathology was squamous cell carcinoma in 20 cases, cloacogenic carcinoma in 3, adenocarcinoma in 2, and basal cell carcinoma in 2. Simulation was performed by PET/CT imaging with patient in treatment position. Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) were drawn on CT and on PET/CT fused images. PET-GTV and PET-CTV were respectively compared to CT-GTV and CT-CTV by Wilcoxon rank test for paired data. PET/CT fused images led to change the stage in 5/27 cases (18.5%): 3 cases from N0 to N2 and 2 from M0 to M1 leading to change the treatment intent from curative to palliative in a case. Based on PET/CT imaging, GTV and CTV contours changed in 15/27 (55.6%) and in 10/27 cases (37.0%) respectively. PET-GTV and PET-CTV resulted significantly smaller than CT-GTV (p = 1.2 × 10 -4 ) and CT-CTV (p = 2.9 × 10 -4 ). PET/CT-GTV and PET/CT-CTV, that were used for clinical purposes, were significantly greater than CT-GTV (p = 6 × 10 -5 ) and CT-CTV (p = 6 × 10 -5 ). FDG-PET/CT has a potential relevant impact in staging and target volume delineation of the carcinoma of the anal canal. Clinical stage variation occurred in 18.5% of cases with change of treatment intent in 3.7%. The GTV and the CTV changed in shape and in size based on PET/CT imaging

When Does Neoadjuvant Chemotherapy Really Avoid Radiotherapy? Clinical Predictors of Adjuvant Radiotherapy in Cervical Cancer.