Beam monitoring in radiotherapy and hadron-therapy

International Nuclear Information System (INIS)

Fontbonne, J.M.

2012-01-01

Radiotherapy techniques have evolved over the past twenty years. For photon beams, the development of tools such as multi leaf collimators, machines such as Cyberknife or tomo-therapy, have improved the conformation of treatments to the tumor volume and lowered maximum dose to healthy tissue. In another register, the use of proton-therapy is expanding in all countries and the development of carbon ions beams for hadron-therapy is also increasing. If techniques improve, the control requirements for the monitoring of the dose administered to patients are always the same. This document presents, first, the ins and outs of the different techniques of external beam radiotherapy: photon treatments, protons and hadrons. Starting from the basis of clinical requirements, it sets the variables to be measured in order to ensure the quality of treatment for the different considered modalities. It then describes some implementations, based on precise and rigorous specifications, for the monitoring and measurement of beams delivered by external beam radiotherapy equipments. Two instrumental techniques are particularly highlighted, plastic scintillators dosimetry for the control of megavoltage photon beams and ionization chamber dosimetry applied to proton-therapy or radiobiology experiments conducted at the GANIL facility. Analyzes and perspectives, based on the recent developments of treatment techniques, are delivered in conclusion and can serve as guide for future instrumental developments. (author)

Selection and determination of beam weights based on genetic algorithms for conformal radiotherapy treatment planning

International Nuclear Information System (INIS)

Xingen Wu; Zunliang Wang

2000-01-01

A genetic algorithm has been used to optimize the selection of beam weights for external beam three-dimensional conformal radiotherapy treatment planning. A fitness function is defined, which includes a difference function to achieve a least-square fit to doses at preselected points in a planning target volume, and a penalty item to constrain the maximum allowable doses delivered to critical organs. Adjustment between the dose uniformity within the target volume and the dose constraint to the critical structures can be achieved by varying the beam weight variables in the fitness function. A floating-point encoding schema and several operators, like uniform crossover, arithmetical crossover, geometrical crossover, Gaussian mutation and uniform mutation, have been used to evolve the population. Three different cases were used to verify the correctness of the algorithm and quality assessment based on dose-volume histograms and three-dimensional dose distributions were given. The results indicate that the genetic algorithm presented here has considerable potential. (author)

Olfactory neural tumours - the role of external beam radiotherapy

International Nuclear Information System (INIS)

Slevin, N.J.; Irwin, C.J.R.; Banerjee, S.S.; Path, F.R.C.; Gupta, N.K.; Farrington, W.T.

1996-01-01

Olfactory neuroblastoma is an uncommon tumour arising in the nasal cavity or paranasal sinuses. We report the management of nine cases treated with external beam radiotherapy subsequent to surgery, either attempted definitive removal or biopsy only. Recent refinements in pathological evaluation of these tumours are discussed. Seven cases were deemed classical olfactory neuroblastoma whilst two were classified as neuroendocrine carcinoma. The clinical features, radiotherapy technique and variable natural history are presented. Seven of eight patients treated radically were controlled locally, with a minimum follow-up of two years. Three patients developed cervical lymph node disease and three patients died of systemic metastatic disease. Suggestions are made as to which patients should have en-bloc resection rather than definitive radiotherapy. (author)

Low grade gliomas: preliminary analysis of failure patterns among patients treated using 3D conformal external beam irradiation

International Nuclear Information System (INIS)

Pu, Anthony T.; Sandler, Howard M.; Radany, Eric H.; Blaivas, Mila; Page, Michaelyn A.; Greenberg, Harry S.; Junck, Larry; Ross, Donald A.

1995-01-01

Purpose: The pattern of failure of low grade gliomas following radiotherapy is less well known than that of the high grade gliomas. Stereotactic histologic studies have suggested that tumor cells extend beyond imaging abnormalities, and that large margins would be required for radiotherapy target volumes to encompass all of the neoplasm. Our experience using computerized tomography (CT)- and magnetic resonance (MR)-planned irradiation of low grade gliomas was reviewed to determine the pattern of tumor recurrence, in an effort to clinically define the minimum margin required. Methods and Materials: Forty-six patients with low grade supratentorial gliomas were treated between April 1985 and November 1992 using three-dimensional (3D) conformal CT- or MR-planned external beam radiotherapy. Fields were designed to encompass a target volume created by adding a margin to the tumor in three dimensions. Generally, patients were treated using shrinking fields with an initial target (tumor plus a 1 to 3 cm margin) treated to a dose of 45 to 50.4 (median 50.4) Gy, and a boost (tumor plus a 0 to 2 cm margin) treated to a total of 54 to 59.4 (median 59.4) Gy. Median follow-up was 32.9 months. Results: There have been 11 failures; all of these occurred within the radiographic abnormality (either T2 prolongation or CT hypodensity) visualized at the time of treatment planning (i.e., all failures were within the boost volume). Median time to failure was 53 months. Because all failures were local, there was no relationship between the amount by which the tumor volumes were expanded to create target volumes and the eventual outcome. Conclusion: Despite pathologic data suggesting that low grade glioma cells can be found outside the MR T2-signal abnormality in many cases, our results demonstrate that conformal external beam radiotherapy, in which the high dose volume is limited, does not result in increased marginal or out-of-field failures. Until control of tumor within the

Influence of boost technique (external beam radiotherapy or brachytherapy) on the outcome of patients with carcinoma of the base of the tongue

International Nuclear Information System (INIS)

Regueiro, C.A.; Millan, I.; Torre, A. de la; Valcarcel, F.J.; Magallon, R.; Fernandez, E.; Aragon, G.

1995-01-01

We reviewed 90 patients with squamous cell carcinoma of the base of the tongue. Fifty-three patients were treated with external beam radiotherapy alone (3 T1, 11 T2, 21 T3, and 18 T4 tumors) and thirty-seven patients were treated with external beam radiotherapy plus brachytherapy boost (4 T1, 15 T2, 11 T3, and 7 T4 tumors). For patients with T1, T2 and T3 primaries, the actuarial 3-year local relapse-free survival was 42% following external beam radiotherapy alone and 67% following external beam radiotherapy plus brachytherapy (p<0.05). The actuarial 3-year cause specific survival for these T-stages was 37% for patients treated with external beam radiotherapy alone and 53% for patients treated with external beam radiotherapy plus brachytherapy (p=0.1). In the Cox multivariate analyses restricted patients with T1, T2 and T3 staged tumors, treatment modality was the only predictor for local control but no influence on specific survival was found. The trend towards significant differences in specific survival found in the univariate comparison of both treatment modalities was probably due to the significantly higher number of N-positive patients treated with external beam radiotherapy alone. When all stages were included in the Cox analysis, low hemoglobin level, invasion of deep muscle, number of palpable nodes, and history of weight loss significantly influenced the outcome. Soft tissue necrosis occurred more frequently in patients treated with external beam radiotherapy plus brachytherapy (33% vs. 10%, p=0.52). (orig.)

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.

External Beam Radiotherapy for Carcinoma of the Extrahepatic Biliary System

International Nuclear Information System (INIS)

Chun, Ha Chung; Lee, Myung Za

1996-01-01

Purpose : To evaluate the effectiveness and tolerance of patients of external beam radiotherapy of carcinoma of the extrahepatic biliary system (EHBS) including gall bladder (GB) and extrahepatic bile ducts (EHBD) and to define the role of radiotherapy for these tumors. Methods and Materials : We retrospectively analyzed the records of 43 patients with carcinoma of the EHBS treated with external beam radiotherapy at our institution between April, 1986 and July, 1994. Twenty three patients had GB cancers and remaining 20 patients did EHBD cancers. Of those 23 GB cancers, 2 had Stage II, 12 did Stage III and 9 did Stage IV disease, respectively. Male to female ratio was 11 to 12. Fifteen patients underwent radical surgery with curative intent and 8 patients did biopsy and bypass surgery alone. Postoperatively 16 patients were irradiated with 4500 cGy or higher doses and 4 patients with 3180 to 4140 cGy. Follow up periods ranged from 8 to 34 months. Results : overall median survival time of patients with GB cancer was 11 months. Median survival time for patients with Stage III and IV disease were 14 months and 5 months, respectively. Corresponding two year survival rates were 36%(4/11) and 13%(1/8), respectively. Those who underwent surgery with curative intent showed significantly better survival at 12 months than those who underwent bypass surgery alone(67% vs 13%). None of the patients died of treatment related complications. Median survival time for entire group of 20 EHBD patients was 10 months. Median survivals of 10 Stage III and 7 Stage IV disease were 10 and 8 months, respectively. Two patients who underwent Whipple's procedure had 11 and 14 month survival and those treated with resection and drainage showed median survival of 10 month. Conclusion : Postoperative external beam radiotherapy for carcinoma of the extrahepatic billary system is well tolerated and might improve survival of patients. especially those with respectable lesions with microscopic or

Beam shaping for conformal fractionated stereotactic radiotherapy: a modeling study

International Nuclear Information System (INIS)

Hacker, Fred L.; Kooy, Hanne M.; Bellerive, Marc R.; Killoran, Joseph H.; Leber, Zachary H.; Shrieve, Dennis C.; Tarbell, Nancy J.; Loeffler, Jay S.

1997-01-01

Purpose: The patient population treated with fractionated stereotactic radiotherapy (SRT) is significantly different than that treated with stereotactic radiosurgery (SRS). Generally, lesions treated with SRT are larger, less spherical, and located within critical regions of the central nervous system; hence, they offer new challenges to the treatment planner. Here a simple, cost effective, beam shaping system has been evaluated relative to both circular collimators and an ideal dynamically conforming system for effectiveness in providing conformal therapy for these lesions. Methods and Materials: We have modeled a simple system for conformal arc therapy using four independent jaws. The jaw positions and collimator angle are changed between arcs but held fixed for the duration of each arc. Eleven previously treated SRT cases have been replanned using this system. The rectangular jaw plans were then compared to the original treatment plans which used circular collimators. The plans were evaluated with respect to tissue sparing at 100%, 80%, 50%, and 20% of the prescription dose. A plan was also done for each tumor in which the beam aperture was continuously conformed to the beams eye view projection of the tumor. This was used as an ideal standard for conformal therapy in the absence of fluence modulation. Results: For tumors with a maximum extent of over 3.5 cm the rectangular jaw plans reduced the mean volume of healthy tissue involved at the prescription dose by 57% relative to the circular collimator plans. The ideal conformal plans offered no significant further improvement at the prescription dose. The relative advantage of the rectangular jaw plans decreased at lower isodoses so that at 20% of the prescription dose tissue involvement for the rectangular jaw plans was equivalent to that for the circular collimator plans. At these isodoses the ideal conformal plans gave substantially better tissue sparing. Conclusion: A simple and economical field shaping

Simultaneous optimization of beam orientations and beam weights in conformal radiotherapy

International Nuclear Information System (INIS)

Rowbottom, Carl Graham; Khoo, Vincent S.; Webb, Steve

2001-01-01

A methodology for the concurrent optimization of beam orientations and beam weights in conformal radiotherapy treatment planning has been developed and tested on a cohort of five patients. The algorithm is based on a beam-weight optimization scheme with a downhill simplex optimization engine. The use of random voxels in the dose calculation provides much of the required speed up in the optimization process, and allows the simultaneous optimization of beam orientations and beam weights in a reasonable time. In the implementation of the beam-weight optimization algorithm just 10% of the original patient voxels are used for the dose calculation and cost function evaluation. A fast simulated annealing algorithm controls the optimization of the beam arrangement. The optimization algorithm was able to produce clinically acceptable plans for the five patients in the cohort study. The algorithm equalized the dose to the optic nerves compared to the standard plans and reduced the mean dose to the brain stem by an average of 4.4% (±1.9, 1 SD), p value=0.007. The dose distribution to the PTV was not compromised by developing beam arrangements via the optimization algorithm. In conclusion, the simultaneous optimization of beam orientations and beam weights has been developed to be routinely used in a realistic time. The results of optimization in a small cohort study show that the optimization can reliably produce clinically acceptable dose distributions and may be able to improve dose distributions compared to those from a human planner

Survey of Stereotactic Body Radiation Therapy in Japan by the Japan 3-D Conformal External Beam Radiotherapy Group

International Nuclear Information System (INIS)

Nagata, Yasushi; Hiraoka, Masahiro; Mizowaki, Takashi; Narita, Yuichiro; Matsuo, Yukinori; Norihisa, Yoshiki; Onishi, Hiroshi; Shirato, Hiroki

2009-01-01

Purpose: To recognize the current status of stereotactic body radiotherapy (SBRT) in Japan, using a nationwide survey conducted by the Japan 3-D Conformal External Beam Radiotherapy Group. Methods and Materials: The questionnaire was sent by mail to 117 institutions. Ninety-four institutions (80%) responded by the end of November 2005. Fifty-three institutions indicated that they have already started SBRT, and 38 institutions had been reimbursed by insurance. Results: A total of 1111 patients with histologically confirmed lung cancer were treated. Among these patients, 637 had T1N0M0 and 272 had T2N0M0 lung cancer. Metastatic lung cancer was found in 702 and histologically unconfirmed lung tumor in 291 patients. Primary liver cancer was found in 207 and metastatic liver cancer in 76 patients. The most frequent schedule used for primary lung cancer was 48Gy in 4 fractions at 22 institutions (52%), followed by 50Gy in 5 fractions at 11 institutions (26%) and 60Gy in 8 fractions at 4 institutions (10%). The tendency was the same for metastatic lung cancer. The average number of personnel involved in SBRT was 1.8 radiation oncologists, including 1.1 certified radiation oncologists, 2.8 technologists, 0.7 nurses, and 0.6 certified quality assurance personnel and 0.3 physicists. The most frequent amount of time for treatment planning was 61-120min, for quality assurance was 50-60min, and for treatment was 30min. There were 14 (0.6% of all cases) reported Grade 5 complications: 11 cases of radiation pneumonitis, 2 cases of hemoptysis, and 1 case of radiation esophagitis. Conclusion: The current status of SBRT in Japan was surveyed.

Cobalt-60 Machines and Medical Linear Accelerators: Competing Technologies for External Beam Radiotherapy.

Science.gov (United States)

Healy, B J; van der Merwe, D; Christaki, K E; Meghzifene, A

2017-02-01

Medical linear accelerators (linacs) and cobalt-60 machines are both mature technologies for external beam radiotherapy. A comparison is made between these two technologies in terms of infrastructure and maintenance, dosimetry, shielding requirements, staffing, costs, security, patient throughput and clinical use. Infrastructure and maintenance are more demanding for linacs due to the complex electric componentry. In dosimetry, a higher beam energy, modulated dose rate and smaller focal spot size mean that it is easier to create an optimised treatment with a linac for conformal dose coverage of the tumour while sparing healthy organs at risk. In shielding, the requirements for a concrete bunker are similar for cobalt-60 machines and linacs but extra shielding and protection from neutrons are required for linacs. Staffing levels can be higher for linacs and more staff training is required for linacs. Life cycle costs are higher for linacs, especially multi-energy linacs. Security is more complex for cobalt-60 machines because of the high activity radioactive source. Patient throughput can be affected by source decay for cobalt-60 machines but poor maintenance and breakdowns can severely affect patient throughput for linacs. In clinical use, more complex treatment techniques are easier to achieve with linacs, and the availability of electron beams on high-energy linacs can be useful for certain treatments. In summary, there is no simple answer to the question of the choice of either cobalt-60 machines or linacs for radiotherapy in low- and middle-income countries. In fact a radiotherapy department with a combination of technologies, including orthovoltage X-ray units, may be an option. Local needs, conditions and resources will have to be factored into any decision on technology taking into account the characteristics of both forms of teletherapy, with the primary goal being the sustainability of the radiotherapy service over the useful lifetime of the equipment

Combined external beam and intraluminal radiotherapy for irresectable Klatskin tumors

Energy Technology Data Exchange (ETDEWEB)

Schleicher, U.M. [Klinik fuer Strahlentherapie, Technische Hochschule Aachen (Germany); Staatz, G. [Klinik fuer Radiologische Diagnostik, Technische Hochschule Aachen (Germany); Alzen, G. [Klinik fuer Radiologische Diagnostik, Technische Hochschule Aachen (Germany); Abt. Kinderradiologie, Giessen Univ. (Germany); Andreopoulos, D. [Klinik fuer Strahlentherapie, Technische Hochschule Aachen (Germany); BOC Oncology Centre, Nikosia (Cyprus)

2002-12-01

Background: In most cases of proximal cholangiocarcinoma, curative surgery is not possible. Radiotherapy can be used for palliative treatment. We report our experience with combined external beam and intraluminal radiotherapy of advanced Klatskin's tumors. Patients and Methods: 30 patients were treated for extrahepatic proximal bile duct cancer. Our schedule consisted for external beam radiotherapy (median dose 30 Gy) and a high-dose-rate brachytherapy boost (median dose 40 Gy) delivered in four or five fractions, which could be applied completely in twelve of our patients. 15 patients in the brachytherapy and nine patients in the non-brachytherapy group received additional low-dose chemotherapy with 5-fluorouracil. Results: The brachytherapy boost dose improved the effect of external beam radiotherapy by increasing survival from a median of 3.9 months in the non-brachytherapy group to 9.1 months in the brachytherapy group. The effect was obvious in patients receiving a brachytherapy dose above 30 Gy, and in those without jaundice at the beginning of radiotherapy (p<0.05). Conclusions: The poor prognosis in patients with advanced Klatskin's tumors may be improved by combination therapy, with the role of brachytherapy and chemotherapy still to be defined. Our results suggest that patients without jaundice should be offered brachytherapy, and that a full dose of more than 30 Gy should be applied. (orig.) [German] Hintergrund: Bei den meisten Patienten mit proximalen Cholangiokarzinomen ist eine kurative Operation nicht mehr moeglich. Im Rahmen der Palliativbehandlung kann die Strahlentherapie eingesetzt werden. Wir berichten ueber unsere Erfahrungen mit der Kombination aus perkutaner und intraluminaler Strahlentherapie fortgeschrittener Klatskin-Tumoren. Patienten und Methode: 30 Patienten wurden wegen extrahepatischer proximaler Gallengangskarzinome behandelt. Unser Therapieschema umfasste eine perkutane Strahlentherapie (mediane Dosis: 30 Gy) sowie einen

Conformal three dimensional radiotherapy treatment planning in Lund

Energy Technology Data Exchange (ETDEWEB)

Knoos, T; Nilsson, P [Lund Univ. (Sweden). Dept. of Radiation Physics; Anders, A [Lund Univ. (Sweden). Dept. of Oncology

1995-12-01

The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam`s eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam`s eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment.

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

Conformal three dimensional radiotherapy treatment planning in Lund

International Nuclear Information System (INIS)

Knoos, T.; Nilsson, P.; Anders, A.

1995-01-01

The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam's eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam's eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment

Results of different modes conformal radiotherapy in treatment of cervical cancer

International Nuclear Information System (INIS)

Baranovs'ka, L.M.; Yivankova, V.S.; Khrulenko, T.V.; Skomorokhova, T.V.; Gorelyina, G.L.

2017-01-01

Development of techniques for cytotoxic treatment applying different modes of conformal radiotherapy, brachytherapy and high-energy (high dose rate - HDR) is one of the promising areas of optimization and efficiency of conservative treatment of patients with regional forms of cervical cancer. At Radiation Oncology Department, National Cancer Institute, 89 patients with stage 2b-3b cervical cancer, aged 29 to 70, underwent examination and combined radiotherapy course. The patients were divided into 2 main groups (56 patients) depending on the mode of developed conformal radiation therapy, and a control group made up by 33 patients (classic, default conformal radiotherapy). Results. Along with external beam radiotherapy, the patients of Group 2 were provided with conformal radiotherapy carried out by means of the linear accelerator of electrons in the mode of enhanced multi fractionation of irradiation dose applied to the small pelvis area (tumor and lymph efflux channels) with the single tumor dose 1.3 Gy twice per day once 4-6 hours up to the total radiation dose of 45 Gy applied to the small pelvis lymph nodes. The patients of Group 1 and the ones of the control group underwent conformal radiotherapy in the mode of standard fractionation applied to the small pelvis area with the single tumor dose of 1.8 Gy up to the total radiation dose of 45 Gy. Conformal radiotherapy was carried out for the patients of Group 1 associated with chemoradiomodifiers (tegafur, cisplatin). At the stage 2 of combined radiotherapy course, all patients underwent HDR brachytherapy via Co60 source in the mode of the single tumor dose of 5 Gy at point A up to the total radiation dose of 35-40 Gy. Therefore, employing accelerated mode of multifractiation in conformal radiotherapy of patients with regional cervical cancer makes it possible to enhance canrcinocidal irradiation doses applied to a tumor, and an interval between radiotherapy fractions provides conditions for initiation of

Conformation radiotherapy and conformal radiotherapy

International Nuclear Information System (INIS)

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)

Indications for quality assurance in conformal radiotherapy in Italy

International Nuclear Information System (INIS)

Banci Buonamici, F.; DE Angelis, C.; Rosi, A.; Tabocchini, M.A.; Iotti, C.; Olmi, P.

2008-01-01

Intensity-Modulated Radiation Therapy (IMRT) is an advanced and promising technique of external beam irradiation. IMRT is able to conform the dose distribution to the 3D tumour shape also for complex geometries, preserving surrounding normal tissues and reducing the probability of side effects. IMRT is a time consuming and complex technique and its use demands high level quality assurance. It is, therefore, very important to define conditions for its utilization. Professionals of Radiotherapy Centres, with experience in the IMRT use, have constituted a multidisciplinary working group with the aim of developing indications in this field. Purpose of the present document is to highlight relevant aspects of the technique, but also to underline the high complexity of the technique, whose implementation requires extreme attention of the staff of Radiotherapy Centres involved [it

A survey of techniques to reduce and manage external beam radiation-induced xerostomia in British oncology and radiotherapy departments

International Nuclear Information System (INIS)

Macknelly, Andrew; Day, Jane

2009-01-01

Xerostomia is the most common side effect of external beam radiotherapy to the head and neck [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et-al. Can dose reduction to one parotid gland prevent xerostomia? - A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy. Clinical Oncology 2006;18(6):497-504.]. A survey was carried out in British oncology departments to determine what treatment regimes, to minimise xerostomia, are used for patients with head-and-neck cancers treated with external beam radiotherapy. A semi-structured questionnaire consisting of both quantitative and qualitative questions was designed that asked departments which of the identified methods they used, why a method might not be currently employed, and whether its use had ever been considered. The study found that there are wide disparities between the techniques employed by oncology departments to avoid and reduce xerostomia in patients with cancers of the head and neck. The National Institute of Clinical Health and Excellence, [National Institute for Clinical Health and Excellence (NICE). Improving outcomes in head and neck cancers: the manual. London: Office of Public Sector Information; 2004.] for example, recommends that patients are given dental care and dietary advice but some departments did not appear to be doing this. Less than half of departments stated that they offer complementary therapies and less than 40% prescribed pilocarpine, a saliva-stimulant. Only two respondents stated that they use amifostine, a radioprotector, during radiotherapy treatment to the head and neck. The results also suggested a move toward using Intensity Modulated Radiotherapy (IMRT) for treating head-and-neck cancers which offers better normal tissue sparing than three-dimensional conformal radiotherapy. [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et al. Can dose reduction to one parotid gland prevent xerostomia

In-vivo (entrance) dose measurements in external beam radiotherapy with aqueous FBX dosimetry system

International Nuclear Information System (INIS)

Semwal, M.K.; Thakur, P.K.; Bansal, A.K.; Vidyasagar, P.B.

2005-01-01

FBX aqueous chemical dosimetry system has been found useful in radiotherapy owing to its low dose measuring capability. In the present work, entrance dose measurements in external beam radiotherapy on a telecobalt machine were carried out with the system on 100 patients. Treatments involving simple beam arrangement of open parallel-opposed beams in cranial and pelvic irradiations were selected for this study. In place of a spectrophotometer, a simple and inexpensive colorimeter was used for absorbance measurements. The purpose was to assess the efficacy of the FBX system for in-vivo dose measurements. The results obtained show that the average discrepancy between the measured and expected dose for both categories of patients was 0.2% (standard deviation 3.2%) with a maximum of +1 0.3%. There were 5.5% cases showing more than ± 5% discrepancy. Comparison of the results obtained with published work on entrance dose measurements, with diode detectors, shows that the inexpensive FBX system can be used for in-vivo (entrance) dose measurements for simple beam arrangements in radiotherapy and can thus serve as a useful QA tool. (author)

Preparation Of Thermoluminescence Dosimeters For External Radiotherapy Beam Audit In Malaysia

International Nuclear Information System (INIS)

Norhayati Abdullah; Siti Sara Deraman; Taiman Kadni; Mohd Taufik Dollah; Norhayati Salleh

2014-01-01

The external beam audit is a part of the Quality Assurance Programme (QAP) in radiotherapy that should be carried out to check the accuracy of dose delivered by the radiotherapy treatment units are within the tolerance limit of A ± 5 % as recommended by the International Commission of Radiation Units and Measurements (ICRU) Report No. 24. In this work, thermoluminescence dosimeters (TLD) in powder form were chosen to be used in the dose quality audit for the radiotherapy treatment units in Malaysia. As a preparation, the characterizations of a new batch of TLD-100 powders were studied. The studies include checks for the response of TLD-100 before and after pre-annealing process, reproducibility and linearity of TL signal. Results show that the response of TLD-100 powder after pre-annealing increases by 65 % compared with before pre-annealing process. These TLD-100 powders also provide reliable and consistent readings for the absorbed dose to water within the range of 150 cGy to 250 cGy with the maximum standard uncertainty of 0.554 μC. Finally, the calibration curves for 6 MV and 10 MV photon beams were established. These curves will be used in determining the absorbed dose to water (Dw) from user's irradiated TLDs. The expanded uncertainty (coverage factor k=2) of Dw determination was estimated to be 4.1 %. As a conclusion, these TLD-100 powders are ready to be used as a transfer detector for evaluating the accuracy of user's delivery dose in the radiotherapy beam audit program in Malaysia. (author)

Evaluation of surface and shallow depth dose reductions using a Superflab bolus during conventional and advanced external beam radiotherapy.

Science.gov (United States)

Yoon, Jihyung; Xie, Yibo; Zhang, Rui

2018-03-01

The purpose of this study was to evaluate a methodology to reduce scatter and leakage radiations to patients' surface and shallow depths during conventional and advanced external beam radiotherapy. Superflab boluses of different thicknesses were placed on top of a stack of solid water phantoms, and the bolus effect on surface and shallow depth doses for both open and intensity-modulated radiotherapy (IMRT) beams was evaluated using thermoluminescent dosimeters and ion chamber measurements. Contralateral breast dose reduction caused by the bolus was evaluated by delivering clinical postmastectomy radiotherapy (PMRT) plans to an anthropomorphic phantom. For the solid water phantom measurements, surface dose reduction caused by the Superflab bolus was achieved only in out-of-field area and on the incident side of the beam, and the dose reduction increased with bolus thickness. The dose reduction caused by the bolus was more significant at closer distances from the beam. Most of the dose reductions occurred in the first 2-cm depth and stopped at 4-cm depth. For clinical PMRT treatment plans, surface dose reductions using a 1-cm Superflab bolus were up to 31% and 62% for volumetric-modulated arc therapy and 4-field IMRT, respectively, but there was no dose reduction for Tomotherapy. A Superflab bolus can be used to reduce surface and shallow depth doses during external beam radiotherapy when it is placed out of the beam and on the incident side of the beam. Although we only validated this dose reduction strategy for PMRT treatments, it is applicable to any external beam radiotherapy and can potentially reduce patients' risk of developing radiation-induced side effects. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Salvage external beam radiotherapy for clinical failure after cryosurgery for prostate cancer

International Nuclear Information System (INIS)

McDonough, Michael J.; Feldmeier, John J.; Parsai, Ishmael; Dobelbower, Ralph R.; Selman, Steven H.

2001-01-01

Purpose: To investigate the role of external beam radiotherapy (EBRT) as salvage treatment of prostate cancer after cryosurgery failure. Methods and Materials: Between 1993 and 1998, 6 patients underwent EBRT with curative intent for local recurrence of prostate cancer after cryosurgery. All 6 patients had biopsy-proven recurrence and palpable disease on digital rectal examination at the time of EBRT. The median follow-up was 34 months (range 8-46). The median prostate-specific antigen level was 2.3 ng/mL (range 0.8-4.1). No patient had evidence of metastatic disease. Two patients received hormonal therapy before beginning EBRT. No patient received hormonal therapy after EBRT completion. The median elapsed time between cryosurgery and EBRT was 3 years (range 1.5-4). The median delivered dose was 66 Gy (range 62-70.2) using a 10-MeV photon beam. An in-house-developed three-dimensional treatment planning system was used to plan delivery of the prescribed dose with conformal radiotherapy techniques. Results: After EBRT, all patients had complete resolution of palpable disease. Four patients (66%) were disease free at the time of the last follow-up. Two patients developed biochemical failure as defined by the American Society for Therapeutic Radiology and Oncology consensus definition. One of these patients had a prostate-specific antigen level of 97 ng/mL before cryosurgery. No patient developed distant metastasis during follow-up. Two patients (33%) developed proctitis; 1 case resolved with Rowasa suppositories and 1 required blood transfusion. Conclusions: Our preliminary results suggest that EBRT can render a significant number of patients biochemically free of disease and can cause complete resolution of clinically palpable disease after initial cryosurgery. The results also showed that EBRT can be given without excessive morbidity. EBRT should be considered as a treatment option in these potentially curable cases

Phase-space database for external beam radiotherapy. Summary report of a consultants' meeting

International Nuclear Information System (INIS)

Capote, R.; Jeraj, R.; Ma, C.M.; Rogers, D.W.O.; Sanchez-Doblado, F.; Sempau, J.; Seuntjens, J.; Siebers, J.V.

2006-01-01

A summary is given of a Consultants' Meeting assembled to discuss and recommend actions and activities to prepare a Phase-space Database for External Beam Radiotherapy. The new database should serve to disseminate phase-space data of those accelerators and 60 Co units used in radiotherapy through the compilation of existing data that have been properly validated. Both the technical discussions and the resulting work plan are described, along with the detailed recommendations for implementation. The meeting was jointly organized by NAPC-Nuclear Data Section and NAHU-Dosimetry and Medical Radiation Physics Section. (author)

Internal hemipelvectomy with intraoperative and external beam radiotherapy in the limb-sparing treatment of a pelvic girdle chondrosarcoma

NARCIS (Netherlands)

Hoekstra, HJ; Szabo, BG

The case of a patient with an extensive pelvic girdle chondrosarcoma treated with internal hemipelvectomy and intraoperative radiotherapy, followed by adjuvant high-dose external beam radiotherapy, with a successful attempt in achieving long-term local tumor control and limb-sparing treatment is

A high-precision system for conformal intracranial radiotherapy

International Nuclear Information System (INIS)

Tome, Wolfgang A.; Meeks, Sanford L.; Buatti, John M.; Bova, Francis J.; Friedman, William A.; Li Zuofeng

2000-01-01

Purpose: Currently, optimally precise delivery of intracranial radiotherapy is possible with stereotactic radiosurgery and fractionated stereotactic radiotherapy. We report on an optimally precise optically guided system for three-dimensional (3D) conformal radiotherapy using multiple noncoplanar fixed fields. Methods and Materials: The optically guided system detects infrared light emitting diodes (IRLEDs) attached to a custom bite plate linked to the patient's maxillary dentition. The IRLEDs are monitored by a commercially available stereo camera system, which is interfaced to a personal computer. An IRLED reference is established with the patient at the selected stereotactic isocenter, and the computer reports the patient's current position based on the location of the IRLEDs relative to this reference position. Using this readout from the computer, the patient may be dialed directly to the desired position in stereotactic space. The patient is localized on the first day and a reference file is established for 5 different couch positions. The patient's image data are then imported into a commercial convolution-based 3D radiotherapy planning system. The previously established isocenter and couch positions are then used as a template upon which to design a conformal 3D plan with maximum beam separation. Results: The use of the optically guided system in conjunction with noncoplanar radiotherapy treatment planning using fixed fields allows the generation of highly conformal treatment plans that exhibit a high degree of dose homogeneity and a steep dose gradient. To date, this approach has been used to treat 28 patients. Conclusion: Because IRLED technology improves the accuracy of patient localization relative to the linac isocenter and allows real-time monitoring of patient position, one can choose treatment-field margins that only account for beam penumbra and image resolution without adding margin to account for larger and poorly defined setup uncertainty. This

Minimal requirements for quality controls in radiotherapy with external beams; Controlli di qualita' essenziali in radioterapia con fasci esterni

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

Physical dosimetric guidelines have been developed by the Italian National Institute of Health study group on quality assurance in radiotherapy to define protocols for quality controls in external beam radiotherapy. While the document does not determine strict rules or firm recommendations, it suggests minimal requirements for quality controls necessary to guarantee an adequate degree of accuracy in external beam radiotherapy. [Italian] Il gruppo di studio Assicurazione di qualita' in radioterapia dell'Istituto Superiore di Sanita' presenta le linee guida per la stesura dei protocolli di controllo di qualita' essenziali necessari a garantire un adeguato livello di accuratezza del trattamento radiante e rappresenta pertanto una parte essenziale del contributo fisico-dosimetrico globale di assicurazione di qualita' in radioterapia con fasci esterni.

Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

DEFF Research Database (Denmark)

Christensen, Anders Nymark; Rydhög, J. S.; Søndergaard, Rikke Vicki

2016-01-01

Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver......-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive (106)Ag......, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy...

In vivo dosimetry in external beam radiotherapy

International Nuclear Information System (INIS)

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

2013-01-01

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

In vivo dosimetry in external beam radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Mijnheer, Ben [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam 1066 CX (Netherlands); Beddar, Sam [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Izewska, Joanna [Division of Human Health, International Atomic Energy Agency, Vienna 1400 (Austria); Reft, Chester [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois 60637 (United States)

2013-07-15

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

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

Biochemical failure after radical external beam radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Nomoto, Satoshi; Imada, Hajime; Kato, Fumio; Yahara, Katsuya; Morioka, Tomoaki; Ohguri, Takayuki; Nakano, Keita; Korogi, Yukunori

2005-01-01

The purpose of this study was to evaluate biochemical failures after radical external beam radiotherapy for prostate cancer. A total of 143 patients with prostate cancer (5 cases in stage A2, 95 in stage B and 43 in stage C; 18 in low risk group, 37 in intermediate risk group, 67 in high risk group and 21 in unknown group) were included in this study. Patients of stage A2 and B underwent external irradiation of 46 Gy to the prostate gland and seminal vesicle and additional 20 Gy to the prostate gland, while patients of stage C underwent external irradiation of 66 Gy to the prostate gland and seminal vesicle including 46 Gy to the pelvis. Neoadjuvant hormonal therapy was done in 66 cases, and long-term hormonal therapy in 75 cases; two cases were treated with radiation therapy alone. The 3-year relapse free survival rates by stage A2, B and C were 100%, 96.7% and 88.1%, respectively. The 3-year relapse free survival rates by low, intermediate and high risk groups were 100%, 92.3% and 89.7%, respectively. Biochemical failure was noted in nine cases during the average observation term of 32.2 months; in this group the median of prostate specific antigen (PSA) value was 2.6 ng/ml, the doubling time was 8.6 months, and the term of biochemical failure was 33.2 months. Six of eight cases with biochemical failure were the neoadjuvant hormonal therapy group, but biochemical no evidence of disease (bNED) curve showed no significant difference between neoadjuvant and long-term hormonal groups. It is supposed that unnecessary hormonal therapies were performed based on the nonspecific diagnosis of biochemical failure after radical radiotherapy in our group of patients. A precise criterion of biochemical failure after radical radiotherapy for prostate cancer is necessary. (author)

Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study

Energy Technology Data Exchange (ETDEWEB)

Mozsa, Emoeke [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Landesklinikum Wiener Neustadt, Department of Radiooncology and Radiotherapy, Wiener Neustadt (Austria); Meszaros, Norbert; Major, Tibor; Froehlich, Georgina; Stelczer, Gabor; Fodor, Janos; Polgar, Csaba [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Sulyok, Zoltan [National Institute of Oncology, Centre of Surgery, Budapest (Hungary)

2014-05-15

The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.) [German] Evaluation der 5-Jahres-Ergebnisse bezueglich Ueberleben, Tumorkontrolle, Nebenwirkungen und Kosmetik nach Teilbrustbestrahlung (APBI) mittels 3-D-konformaler, akzelerierter Radiotherapie (3D-CRT). Zwischen 2006 und 2011 wurden 44 Patienten mit Brustkrebs im Stadium I-II und niedrigem Risikoprofil brusterhaltend operiert. Die adjuvante, 3-D-konformale APBI wurde mittels 3-5 nonkoplanarer Feldern durchgefuehrt. Die Gesamtdosis betrug 36,9 Gy bei 9 -mal 4,1 Gy b.i.d.. Nach

Minimal requirements for quality controls in radiotherapy with external beams; Controlli di qualita' essenziali in radioterapia con fasci esterni

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

Physical dosimetric guidelines have been developed by the Italian National Institute of Health study group on quality assurance in radiotherapy to define protocols for quality controls in external beam radiotherapy. While the document does not determine strict rules or firm recommendations, it suggests minimal requirements for quality controls necessary to guarantee an adequate degree of accuracy in external beam radiotherapy. [Italian] Il gruppo di studio Assicurazione di qualita' in radioterapia dell'Istituto Superiore di Sanita' presenta le linee guida per la stesura dei protocolli di controllo di qualita' essenziali necessari a garantire un adeguato livello di accuratezza del trattamento radiante e rappresenta pertanto una parte essenziale del contributo fisico-dosimetrico globale di assicurazione di qualita' in radioterapia con fasci esterni.

Patterns of failure in children with medulloblastoma treated with 3D conformal radiotherapy

International Nuclear Information System (INIS)

Skowronska-Gardas, Anna; Chojnacka, Marzanna; Morawska-Kaczynska, Marzena; Perek, Danuta; Perek-Polnik, Marta

2007-01-01

Background and purpose: Craniospinal irradiation for medulloblastoma is one of the most complex techniques employed in radiotherapy. Many reports stress the impact of irradiation quality on survival in these patients. Our report presents the outcome and patterns of failure for 95 patients treated with 3D conformal radiotherapy (3D-CRT). Materials and methods: From 1998 to 2003, 95 children with medulloblastoma received 3D conformal radiotherapy. All of them were previously treated with surgery and chemotherapy. The brain and upper spinal cord were treated with two lateral 6 MV photon fields. In four patients, the cribriform plate was irradiated by the additional field. For primary tumour bed we applied two or three photon beams. Spinal cord was irradiated either with 18-20 MeV electron fields or with a mixed beam. Results: With a median follow-up of 48 months, 32/95 patients suffered a multifocal (21) or isolated (11) recurrence. We evaluated every primary site of failure. In all patients, the recurrence appeared within the isodose level of 95-100%. Conclusions: Patterns of failure in medulloblastoma patients treated with 3D conformal radiotherapy indicated that the relapse was mainly associated with poor response to pre-irradiation chemotherapy. We believe that 3D conformal radiotherapy allows avoiding failures, related to radiotherapy uncertainties

Adjuvant external beam radiotherapy in the treatment of endometrial cancer (MRC ASTEC and NCIC CTG EN.5 randomised trials): pooled trial results, systematic review, and meta-analysis.

Science.gov (United States)

Blake, P; Swart, Ann Marie; Orton, J; Kitchener, H; Whelan, T; Lukka, H; Eisenhauer, E; Bacon, M; Tu, D; Parmar, M K B; Amos, C; Murray, C; Qian, W

2009-01-10

Early endometrial cancer with low-risk pathological features can be successfully treated by surgery alone. External beam radiotherapy added to surgery has been investigated in several small trials, which have mainly included women at intermediate risk of recurrence. In these trials, postoperative radiotherapy has been shown to reduce the risk of isolated local recurrence but there is no evidence that it improves recurrence-free or overall survival. We report the findings from the ASTEC and EN.5 trials, which investigated adjuvant external beam radiotherapy in women with early-stage disease and pathological features suggestive of intermediate or high risk of recurrence and death from endometrial cancer. Between July, 1996, and March, 2005, 905 (789 ASTEC, 116 EN.5) women with intermediate-risk or high-risk early-stage disease from 112 centres in seven countries (UK, Canada, Poland, Norway, New Zealand, Australia, USA) were randomly assigned after surgery to observation (453) or to external beam radiotherapy (452). A target dose of 40-46 Gy in 20-25 daily fractions to the pelvis, treating five times a week, was specified. Primary outcome measure was overall survival, and all analyses were by intention to treat. These trials were registered ISRCTN 16571884 (ASTEC) and NCT 00002807 (EN.5). After a median follow-up of 58 months, 135 women (68 observation, 67 external beam radiotherapy) had died. There was no evidence that overall survival with external beam radiotherapy was better than observation, hazard ratio 1.05 (95% CI 0.75-1.48; p=0.77). 5-year overall survival was 84% in both groups. Combining data from ASTEC and EN.5 in a meta-analysis of trials confirmed that there was no benefit in terms of overall survival (hazard ratio 1.04; 95% CI 0.84-1.29) and can reliably exclude an absolute benefit of external beam radiotherapy at 5 years of more than 3%. With brachytherapy used in 53% of women in ASTEC/EN.5, the local recurrence rate in the observation group at 5 years

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

Pain flare following external beam radiotherapy and meaningful change in pain scores in the treatment of bone metastases

International Nuclear Information System (INIS)

Chow, Edward; Ling, Alison; Davis, Lori; Panzarella, Tony; Danjoux, Cyril

2005-01-01

Background and purpose: To examine the incidence of pain flare following external beam radiotherapy and to determine what constitutes a meaningful change in pain scores in the treatment of bone metastases. Patients and methods: Patients with bone metastases treated with external beam radiotherapy were asked to score their pain on a scale of 0-10 before the treatment (baseline), daily during the treatment and for 10 days after completion of external beam radiation. Pain flare was defined as a two-point increase from baseline pain in the pain scale of 0-10 with no decrease in analgesic intake or a 25% increase in analgesic intake employing daily oral morphine equivalent with no decrease in pain score. To distinguish pain flare from progression of pain, we required the pain score and analgesic intake to return back to baseline levels after the increase/flare. They were also asked to indicate if their pain changed during that time compared to pre-treatment level. The change in pain score was compared with patient perception. Results: Eighty-eight patients were evaluated in this study. There were 49 male and 39 female patients with the median age of 70 years. Twelve of 88 patients (14%) had pain flare on day 1. The overall incidence of pain flare during the study period ranged from 2 to 16%. A total of 797 pain scorings were obtained. Patients perceived an improvement in pain when their self-reported pain score decreased by at least two points. Conclusions: Our study confirms the occurrence of pain flare following the external beam radiotherapy in the treatment of bone metastases. Further studies are required to predict who are at risk for flare. Appropriate measures can be taken to alleviate the pain flare. The finding in the meaningful change in pain scores supports the investigator-defined partial response used in some clinical trials

External Beam Radiotherapy for Clinically Localized Hormone-Refractory Prostate Cancer: Clinical Significance of Nadir Prostate-Specific Antigen Value Within 12 Months

International Nuclear Information System (INIS)

Ogawa, Kazuhiko; Nakamura, Katsumasa; Sasaki, Tomonari; Onishi, Hiroshi; Koizumi, Masahiko; Shioyama, Yoshiyuki; Araya, Masayuki; Mukumoto, Nobutaka M.S.; Mitsumori, Michihide; Teshima, Teruki

2009-01-01

Purpose: To analyze retrospectively the results of external beam radiotherapy for clinically localized hormone-refractory prostate cancer and investigate the clinical significance of nadir prostate-specific antigen (PSA) value within 12 months (nPSA12) as an early estimate of clinical outcomes after radiotherapy. Methods and Materials: Eighty-four patients with localized hormone-refractory prostate cancer treated with external beam radiotherapy were retrospectively reviewed. The total radiation doses ranged from 30 to 76 Gy (median, 66 Gy), and the median follow-up period for all 84 patients was 26.9 months (range, 2.7-77.3 months). Results: The 3-year actuarial overall survival, progression-free survival (PFS), and local control rates in all 84 patients after radiotherapy were 67%, 61%, and 93%, respectively. Although distant metastases and/or regional lymph node metastases developed in 34 patients (40%) after radiotherapy, local progression was observed in only 5 patients (6%). Of all 84 patients, the median nPSA12 in patients with clinical failure and in patients without clinical failure was 3.1 ng/mL and 0.5 ng/mL, respectively. When dividing patients according to low (<0.5 ng/mL) and high (≥0.5 ng/mL) nPSA12 levels, the 3-year PFS rate in patients with low nPSA12 and in those with high nPSA12 was 96% and 44%, respectively (p < 0.0001). In univariate analysis, nPSA12 and pretreatment PSA value had a significant impact on PFS, and in multivariate analysis nPSA12 alone was an independent prognostic factor for PFS after radiotherapy. Conclusions: External beam radiotherapy had an excellent local control rate for clinically localized hormone-refractory prostate cancer, and nPSA12 was predictive of clinical outcomes after radiotherapy.

Second cancer incidence risk estimates using BEIR VII models for standard and complex external beam radiotherapy for early breast cancer

Energy Technology Data Exchange (ETDEWEB)

Donovan, E. M.; James, H.; Bonora, M.; Yarnold, J. R.; Evans, P. M. [Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton SM2 5PT (United Kingdom); Physics Department, Ipswich Hospital NHS Foundation Trust, Ipswich IP4 5PD (United Kingdom); Department of Academic Radiotherapy, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom and School of Radiotherapy, University of Milan, Milan 20122 (Italy); Department of Academic Radiotherapy, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton SM2 5PT (United Kingdom); Centre for Vision Speech and Signal Processing, University of Surrey, Guildford GU2 7XH (United Kingdom)

2012-10-15

Purpose: To compare organ specific cancer incidence risks for standard and complex external beam radiotherapy (including cone beam CT verification) following breast conservation surgery for early breast cancer.Method: Doses from breast radiotherapy and kilovoltage cone beam CT (CBCT) exposures were obtained from thermoluminescent dosimeter measurements in an anthropomorphic phantom in which the positions of radiosensitive organs were delineated. Five treatment deliveries were investigated: (i) conventional tangential field whole breast radiotherapy (WBRT), (ii) noncoplanar conformal delivery applicable to accelerated partial beast irradiation (APBI), (iii) two-volume simultaneous integrated boost (SIB) treatment, (iv) forward planned three-volume SIB, and (v) inverse-planned three volume SIB. Conformal and intensity modulated radiotherapy methods were used to plan the complex treatments. Techniques spanned the range from simple methods appropriate for patient cohorts with a low cancer recurrence risk to complex plans relevant to cohorts with high recurrence risk. Delineated organs at risk included brain, salivary glands, thyroid, contralateral breast, left and right lung, esophagus, stomach, liver, colon, and bladder. Biological Effects of Ionizing Radiation (BEIR) VII cancer incidence models were applied to the measured mean organ doses to determine lifetime attributable risk (LAR) for ages at exposure from 35 to 80 yr according to radiotherapy techniques, and included dose from the CBCT imaging. Results: All LAR decreased with age at exposure and were lowest for brain, thyroid, liver, and bladder (<0.1%). There was little dependence of LAR on radiotherapy technique for these organs and for colon and stomach. LAR values for the lungs for the three SIB techniques were two to three times those from WBRT and APBI. Uncertainties in the LAR models outweigh any differences in lung LAR between the SIB methods. Constraints in the planning of the SIB methods ensured that

Second cancer incidence risk estimates using BEIR VII models for standard and complex external beam radiotherapy for early breast cancer

International Nuclear Information System (INIS)

Donovan, E. M.; James, H.; Bonora, M.; Yarnold, J. R.; Evans, P. M.

2012-01-01

Purpose: To compare organ specific cancer incidence risks for standard and complex external beam radiotherapy (including cone beam CT verification) following breast conservation surgery for early breast cancer.Method: Doses from breast radiotherapy and kilovoltage cone beam CT (CBCT) exposures were obtained from thermoluminescent dosimeter measurements in an anthropomorphic phantom in which the positions of radiosensitive organs were delineated. Five treatment deliveries were investigated: (i) conventional tangential field whole breast radiotherapy (WBRT), (ii) noncoplanar conformal delivery applicable to accelerated partial beast irradiation (APBI), (iii) two-volume simultaneous integrated boost (SIB) treatment, (iv) forward planned three-volume SIB, and (v) inverse-planned three volume SIB. Conformal and intensity modulated radiotherapy methods were used to plan the complex treatments. Techniques spanned the range from simple methods appropriate for patient cohorts with a low cancer recurrence risk to complex plans relevant to cohorts with high recurrence risk. Delineated organs at risk included brain, salivary glands, thyroid, contralateral breast, left and right lung, esophagus, stomach, liver, colon, and bladder. Biological Effects of Ionizing Radiation (BEIR) VII cancer incidence models were applied to the measured mean organ doses to determine lifetime attributable risk (LAR) for ages at exposure from 35 to 80 yr according to radiotherapy techniques, and included dose from the CBCT imaging. Results: All LAR decreased with age at exposure and were lowest for brain, thyroid, liver, and bladder (<0.1%). There was little dependence of LAR on radiotherapy technique for these organs and for colon and stomach. LAR values for the lungs for the three SIB techniques were two to three times those from WBRT and APBI. Uncertainties in the LAR models outweigh any differences in lung LAR between the SIB methods. Constraints in the planning of the SIB methods ensured that

A survey on the state on the use of conformation radiotherapy units in Japan

International Nuclear Information System (INIS)

Tomaru, Teizo; Onai, Yoshio; Abe, Shunsuke

1985-01-01

A survey on the stage on the use of conformation radiotherapy units in Japan was performed by the Radiotherapy Equipments Committee of the Japanese Association for Radiotherapy Systems. The questionnaire was sent to 34 hospitals, which are all the hospitals equipped with these units, and 13 cancer and adult disease centers. The answers were collected from 42 hospitals, of which the 31 from formers and 11 from latters. In June, 1984, 27 conformation radiotherapy units (11 units with a pair of lower jaws and 16 units with multi-leaf collimators) were being used at 26 hospitals answered to questionnaire. During a month from May 16 to June 15 in 1984, conformation radiotherapy was performed at 10 hopsitals, and mean number of patients per day treated with these irradiation techniques was 3.7 +- 3.5. Fixed beam radiotherapy with irregular shape fields using multi-leaf collimators was also performed at 8 hospitals and mean number of patients per day treated with this fixed beam was 6.6 +- 3.9. Hollow-out irradiation technique was used at 4 hospitals, and 3.8 patients per day per hospital were treated with this technique. (author)

Dosimetric comparison between intensity modulated brachytherapy versus external beam intensity modulated radiotherapy for cervix cancer: a treatment planning study

International Nuclear Information System (INIS)

Subramani, V.; Sharma, D.N.; Jothy Basu, K.S.; Rath, G.K.; Gopishankar, N.

2008-01-01

To evaluate the dosimetric superiority of intensity modulated brachytherapy (IMBT) based on inverse planning optimization technique with classical brachytherapy optimization and also with external beam intensity modulated radiotherapy planning technique in patients of cervical carcinoma

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)

The international protocol for the dosimetry of external radiotherapy beams based on standards of absorbed dose to water

International Nuclear Information System (INIS)

Andreo, P.

2001-01-01

An International Code of Practice (CoP, or dosimetry protocol) for external beam radiotherapy dosimetry based on standards of absorbed dose to water has been published by the IAEA on behalf of IAEA, WHO, PAHO and ESTRO. The CoP provides a systematic and internationally unified approach for the determination of the absorbed dose to water in reference conditions with radiotherapy beams. The development of absorbed-dose-to-water standards for high-energy photons and electrons offers the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. Many laboratories already provide calibrations at the radiation quality of 60Co gamma-rays and some have extended calibrations to high-energy photon and electron beams. The dosimetry of kilovoltage x-rays, as well as that of proton and ion beams can also be based on these standards. Thus, a coherent dosimetry system based on the same formalism is achieved for practically all radiotherapy beams. The practical use of the CoP as simple. The document is formed by a set of different CoPs for each radiation type, which include detailed procedures and worksheets. All CoPs are based on ND,w chamber calibrations at a reference beam quality Qo, together with radiation beam quality correction factors kQ preferably measured directly for the user's chamber in a standards laboratory. Calculated values of kQ are provided together with their uncertainty estimates. Beam quality specifiers are 60Co, TPR20,10 (high-energy photons), R50 (electrons), HVL and kV (x-rays) and Rres (protons and ions) [es

A Bile Duct Cancer Patient Whose Stent Shifted Significantly Over the Course of External Beam Radiotherapy

International Nuclear Information System (INIS)

Yun, Hyong Geun

2011-01-01

The author reports a bile duct cancer patient whose stent shifted significantly from right to left over the course of radiotherapy. The 80-year-old female patient had a short stature with thoracic kyphosis and mutiple spinal compression fractures. She was also emaciated and very lean. By comparing the weekly scanned computed tomography images, the author found her stent to have shifted by more than 4 cm from right to left over the course of external beam radiotherapy. The results of this case study suggest that for a very lean and emaciated kyphotic bile duct cancer patient, the possibility of large interfractional movement of the bile duct or stent during radiotherapy should be considered.

Changes in Pulmonary Function After Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, or Proton Beam Therapy for Non-Small-Cell Lung Cancer

International Nuclear Information System (INIS)

Lopez Guerra, Jose L.; Gomez, Daniel R.; Zhuang Yan; Levy, Lawrence B.; Eapen, George; Liu, Hongmei; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Liao Zhongxing

2012-01-01

Purpose: To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-cell lung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics. Patients and Methods: We analyzed 250 patients who had received ≥60 Gy radio(chemo)therapy for primary NSCLC in 1998–2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient’s preradiation value at the following time intervals: 0–4 (T1), 5–8 (T2), and 9–12 (T3) months. Results: Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC. Conclusions: Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy

External beam radiotherapy for subretinal neovascularization in age-related macular degeneration: is this treatment efficient?

International Nuclear Information System (INIS)

Staar, Susanne; Krott, Ralf; Mueller, Rolf-Peter; Bartz-Schmidt, Karl U.; Heimann, Klaus

1999-01-01

Purpose: Control of the natural course of sub retinal neovascularization (SRNV) in age-related macular degeneration (AMD) is difficult. Only a subset of patients is suitable for laser coagulation. This prospective study aimed to determine the efficacy and individual benefit of external beam radiotherapy (EBRT). Methods and Materials: The prospective trial included 287 patients with subfoveal neovascularization due to AMD which was verified by fluorescein angiography. Patients have been treated between January 1996 and October 1997. All patients received a total dose of 16 Gy in 2-Gy daily fractions with 5-6 MeV photons based on computerized treatment planning in individual head mask fixation. This first analysis is based on 73 patients (50 women, 23 men, median age 74.3 years), with a median follow-up of 13.3 months and a minimum follow-up of 11 months. Results: All patients completed therapy and tolerability was good. First clinical control with second angiography was performed 6 weeks after irradiation, then in 3-month intervals. Eighteen patients with SRNV refusing radiotherapy served as a control group and were matched with 18 irradiated patients. After 7 months median visual acuity (VA) was 20/160 for the irradiated and 20/400 for the untreated patients. One year after radiotherapy final median VA was 20/400 in both groups. Conclusion: These results suggest that 16 Gy of conventionally fractionated external beam irradiation slows down the visual loss in exudative AMD for only a few months. Patients' reading vision could not be saved for a long-term run

Intraoperative and external beam radiotherapy for pancreatic carcinoma; Intraoperative und perkutane Radiotherapie des Pankreaskarzinoms

Energy Technology Data Exchange (ETDEWEB)

Eble, M.J. [Abt. Klinische Radiologie, Radiologische Universitaetsklinik Heidelberg (Germany); Maurer, U. [Klinikum der Stadt Mannheim (Germany). Inst. fuer Radiologie

1996-05-01

Therapeutic strategies in the treatment of pancreatic carcinoma are based on the high number of non-resectable cancers, the high relative radioresistance and the high distant metastases rate. Even in curatively resected carcinomas, a locally effective treatment modality is needed because of the risk of microscopical residual disease in the peripancreatic tissue. The efficacy of radiotherapy is dose dependent. Based on an analysis of published data a dose of more than 50 Gy is recommended, resulting in a high morbidity rate with external beam radiotherapy alone. The use of intraoperative radiotherapy allows locally restricted dose escalation without increased perioperative morbidity. In adjuvant and in primary treatment, local tumor control was improved (70-90%). With palliative intent, pain relief was obtained rapidly in over 60% of patients and led to improved patient performance. As a result of the high distant metastases rate, even in curatively resected carcinomas, the overall prognosis could not be significantly improved. Further dose escalation is limited by the increasing incidence of upper gastrointestinal bleeding (20-30%). (orig.) [Deutsch] Therapiestrategien beim Pankreaskarzinom werden bestimmt durch den hohen Anteil primaer nicht resektabler Karzinome, der hohen relativen Strahlenresistenz und der hohen Fernmetastasierungsrate. Selbst kurativ resezierte Karzinome erfordern durch ihre hohe lokale Tumorzellpersistenz eine lokal effektive adjuvante Behandlungsmassnahme. Die Effektivitaet einer Radiotherapie ist dosisabhaengig. Aus der Analyse publizierter Daten wird eine Dosis von >50 Gy, welche bei der alleinigen perkutanen Bestrahlung mit einer hohen Morbiditaet verbunden ist, empfohlen. Mit der intraoperativen Radiotherapie ist eine lokal begrenzte Dosiseskalation ohne erhoehte perioperative Morbiditaet moeglich. Sowohl in der adjuvanten als auch in der primaeren Behandlung kann die lokale Tumorkontrolle deutlich verbessert werden (70-90%). Unter

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)

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.

Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement

Energy Technology Data Exchange (ETDEWEB)

Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A. [University Hospital of Goettingen, Department of Radiotherapy and Radiation Oncology, Goettingen (Germany); Canis, M. [University of Goettingen, Department of Otorhinolaryngology, Head and Neck Surgery, Goettingen (Germany); Alt-Epping, B. [University of Goettingen, Department of Palliative Medicine, Goettingen (Germany)

2014-02-15

Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting. (orig.)

Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement

International Nuclear Information System (INIS)

Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A.; Canis, M.; Alt-Epping, B.

2014-01-01

Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting. (orig.)

Dosimetric comparison of intensity-modulated, conformal, and four-field pelvic radiotherapy boost plans for gynecologic cancer: a retrospective planning study

International Nuclear Information System (INIS)

Chan, Philip; Yeo, Inhwan; Perkins, Gregory; Fyles, Anthony; Milosevic, Michael

2006-01-01

To evaluate intensity-modulated radiation therapy (IMRT) as an alternative to conformal radiotherapy (CRT) or 4-field box boost (4FB) in women with gynecologic malignancies who are unsuitable for brachytherapy for technical or medical reasons. Dosimetric and toxicity information was analyzed for 12 patients with cervical (8), endometrial (2) or vaginal (2) cancer previously treated with external beam pelvic radiotherapy and a CRT boost. Optimized IMRT boost treatment plans were then developed for each of the 12 patients and compared to CRT and 4FB plans. The plans were compared in terms of dose conformality and critical normal tissue avoidance. The median planning target volume (PTV) was 151 cm 3 (range 58–512 cm 3 ). The median overlap of the contoured rectum with the PTV was 15 (1–56) %, and 11 (4–35) % for the bladder. Two of the 12 patients, both with large PTVs and large overlap of the contoured rectum and PTV, developed grade 3 rectal bleeding. The dose conformity was significantly improved with IMRT over CRT and 4FB (p ≤ 0.001 for both). IMRT also yielded an overall improvement in the rectal and bladder dose-volume distributions relative to CRT and 4FB. The volume of rectum that received the highest doses (>66% of the prescription) was reduced by 22% (p < 0.001) with IMRT relative to 4FB, and the bladder volume was reduced by 19% (p < 0.001). This was at the expense of an increase in the volume of these organs receiving doses in the lowest range (<33%). These results indicate that IMRT can improve target coverage and reduce dose to critical structures in gynecologic patients receiving an external beam radiotherapy boost. This dosimetric advantage will be integrated with other patient and treatment-specific factors, particularly internal tumor movement during fractionated radiotherapy, in the context of a future image-guided radiation therapy study

Bladder filling variation during conformal radiotherapy for rectal cancer

Science.gov (United States)

Sithamparam, S.; Ahmad, R.; Sabarudin, A.; Othman, Z.; Ismail, M.

2017-05-01

Conformal radiotherapy for rectal cancer is associated with small bowel toxicity mainly diarrhea. Treating patients with a full bladder is one of the practical solutions to reduce small bowel toxicity. Previous studies on prostate and cervix cancer patients revealed that maintaining consistent bladder volume throughout radiotherapy treatment is challenging. The aim of this study was to measure bladder volume variation throughout radiotherapy treatment. This study also measured the association between bladder volume changes and diarrhea. Twenty two rectal cancer patients were recruited prospectively. Patients were planned for treatment with full bladder following departmental bladder filling protocol and the planning bladder volume was measured during CT-simulation. During radiotherapy, the bladder volume was measured weekly using cone-beam computed tomography (CBCT) and compared to planning bladder volume. Incidence and severity of diarrhea were recorded during the weekly patient review. There was a negative time trend for bladder volume throughout five weeks treatment. The mean bladder volume decreased 18 % from 123 mL (SD 54 mL) during CT-simulation to 101 mL (SD 71 mL) on the 5th week of radiotherapy, but the decrease is not statistically significant. However, there was a large variation of bladder volume within each patient during treatment. This study showed an association between changes of bladder volume and diarrhea (P = 0.045). In conclusion bladder volume reduced throughout radiotherapy treatment for conformal radiotherapy for rectal cancer and there was a large variation of bladder volume within patients.

Bladder filling variation during conformal radiotherapy for rectal cancer

International Nuclear Information System (INIS)

Sithamparam, S; Ahmad, R; Sabarudin, A; Othman, Z; Ismail, M

2017-01-01

Conformal radiotherapy for rectal cancer is associated with small bowel toxicity mainly diarrhea. Treating patients with a full bladder is one of the practical solutions to reduce small bowel toxicity. Previous studies on prostate and cervix cancer patients revealed that maintaining consistent bladder volume throughout radiotherapy treatment is challenging. The aim of this study was to measure bladder volume variation throughout radiotherapy treatment. This study also measured the association between bladder volume changes and diarrhea. Twenty two rectal cancer patients were recruited prospectively. Patients were planned for treatment with full bladder following departmental bladder filling protocol and the planning bladder volume was measured during CT-simulation. During radiotherapy, the bladder volume was measured weekly using cone-beam computed tomography (CBCT) and compared to planning bladder volume. Incidence and severity of diarrhea were recorded during the weekly patient review. There was a negative time trend for bladder volume throughout five weeks treatment. The mean bladder volume decreased 18 % from 123 mL (SD 54 mL) during CT-simulation to 101 mL (SD 71 mL) on the 5th week of radiotherapy, but the decrease is not statistically significant. However, there was a large variation of bladder volume within each patient during treatment. This study showed an association between changes of bladder volume and diarrhea (P = 0.045). In conclusion bladder volume reduced throughout radiotherapy treatment for conformal radiotherapy for rectal cancer and there was a large variation of bladder volume within patients. (paper)

Evaluation of the treatment planning system of three-dimensional conformal external radiotherapy in Hospital Mexico of San Jose, Costa Rica

International Nuclear Information System (INIS)

Venegas Rojas, Deybith

2014-01-01

An evaluation and analysis are realized of dosimetry of the treatment planning system (TPS) of three-dimensional conformal external radiotherapy in the Servicio de Radioterapia of the Hospital Mexico of Costa Rica. An evaluation procedure is proposed based on IAEA-TECDOC-1540 document, and may continue to be applied periodically in this or other radiotherapy services. Tests realized have checked the representation of distances and electronics densities transferred to the TPS, match with those of real objects. The 16 tests applied have represented situations of real treatments with different configurations and beam modifiers in the equipment used daily. The tests have measured the absorbed dose to water in different significant points at different depths, using photon beams of 6 MeV and 18 MeV. The physical parameters of the tests were simulated. The absorbed dose has been calculated at specified points. The XiO and Eclipse TPS have been used with the calculation algorithms: Superposition, Convolution and AAA. The results of the calculations are evaluated with statistical methods and comparing them with the measurements of absorbed dose. A generalized tendency has been detected toward negative relative errors, implying an underestimation of the dose by the TPS; due to a difference found in the accelerator output factor respect to its commissioning. The AAA algorithm has determined a better performance, although with greater difficulties of calculus in the region of build-up. Convolution and Superposition algorithms have had similar performances and both have presented problems in high depths and out of edges of the fields. The result of the dosimetric evaluation has been satisfactory in real conditions of equipment; but several particularities have been found that should be reviewed and adjusted. The precision of the TPS has been adequate in the majority of situations important for treatment planning. [author] [es

Accelerated partial breast irradiation with external beam radiotherapy. First results of the German phase 2 trial

Energy Technology Data Exchange (ETDEWEB)

Ott, Oliver J.; Strnad, Vratislav; Stillkrieg, Wilhelm; Fietkau, Rainer [University Hospital Erlangen, Department of Radiation Oncology, Erlangen (Germany); Uter, Wolfgang [University Erlangen-Nuremberg, Dept. of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Beckmann, Matthias W. [University Hospital Erlangen, Dept. of Gynecology, Erlangen (Germany)

2017-01-15

To evaluate the feasibility and efficacy of external beam three-dimensional (3D) conformal accelerated partial breast irradiation (APBI) for selected patients with early breast cancer. Between 2011 and 2016, 72 patients were recruited for this prospective phase 2 trial. Patients were eligible for APBI if they had histologically confirmed breast cancer or pure ductal carcinoma in situ (DCIS), a tumor diameter ≤3 cm, clear resection margins ≥2 mm, no axillary lymph node involvement, no distant metastases, tumor bed clips, and were aged ≥50 years. Patients were excluded if mammography showed a multicentric invasive growth pattern, or if they had residual diffuse microcalcifications postoperatively, an extensive intraductal component, or vessel invasion. Patients received 3D conformal external beam APBI with a total dose of 38 Gy in 10 fractions in 1-2 weeks. The trial had been registered at the German Clinical Trials Register, DRKS-ID: DRKS00004417. Median follow-up was 25.5 months (range 1-61 months). Local control was maintained in 71 of 72 patients. The 3-year local recurrence rate was 2.1% (95% confidence interval, CI: 0-6.1%). Early toxicity (grade 1 radiodermatitis) was seen in 34.7% (25/72). Late side effects ≥ grade 3 did not occur. Cosmetic results were rated as excellent/good in 96.7% (59/61). APBI with external beam radiotherapy techniques is feasible with low toxicity and, according to the results of the present and other studies, on the way to becoming a standard treatment option for a selected subgroup of patients. (orig.) [German] Untersuchung der Vertraeglichkeit und Sicherheit der externen, 3-D-konformalen akzelerierten Teilbrustbestrahlung (APBI) fuer ausgewaehlte Patientinnen mit einem fruehen Mammakarzinom. Von 2011 bis 2016 wurden 72 Patientinnen in diese prospektive Phase-2-Studie eingebracht. Einschlusskriterien waren ein histologisch gesichertes Mammakarzinom oder DCIS, ein Tumordurchmesser ≤ 3 cm, tumorfreie Resektionsraender ≥ 2

Radiation dose to laterally transposed ovaries during external beam radiotherapy for cervical cancer

International Nuclear Information System (INIS)

Mazonakis, Michael; Damilakis, John; Varveris, Haris; Gourtsoyiannis, Nicholas

2006-01-01

The purpose of this study was to estimate the radiation dose to laterally transposed ovaries from external beam radiotherapy for cervical cancer. Dose measurements were performed in a modified humanoid phantom using a 6 MV photon beam. The dependence of the ovarian dose upon the field size, the distance from the primary irradiation field and the presence of wedges or gonadal shielding was determined. For a tumor dose of 45 Gy, ovarian dose was 0.88-8.51 Gy depending on the field size employed and the location of the transposed ovary in respect to the treatment field. Positioning of 7 cm thick shielding reduced the dose to ovary by less than 19%. The use of wedges increased the ovarian dose by a factor up to 1.5. Accurate radiographic localization of the ovaries allows the use of the presented dosimetric results to obtain a reasonable prediction of the ovarian dose

Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement.

Science.gov (United States)

Dröge, L H; Hinsche, T; Canis, M; Alt-Epping, B; Hess, C F; Wolff, H A

2014-02-01

Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting.

Conformal intensity-modulated radiotherapy (IMRT) delivered by robotic linac-conformality versus efficiency of dose delivery

International Nuclear Information System (INIS)

Webb, Steve

2000-01-01

Intensity-modulated radiotherapy (IMRT) may be delivered with a high-energy-photon linac mounted on a robotic gantry and executing a complex trajectory. In a previous paper an inverse-planning technique was developed for such an application. Here the work is extended to demonstrate the dependence of conformality on the size of the elemental pencil beam, on the complexity of the trajectory and on the sampling of azimuth and elevation of the collimated source. The improved conformality of complex trajectories is demonstrated and benchmarked relative to simpler trajectories, more representative of existing non-robotic IMRT techniques. Specifically, by choosing a very fine pencil beam, exquisitely conformal dose distributions have been obtained. Important sampling considerations have been determined. Expressions have been derived for the dosimetry and monitor-unit efficiency of robotic IMRT. Equivalent trajectories were computed for executing the complex robotic trajectories instead by using a conventional linac. The work benchmarks an ideal in IMRT against which more practical and more common techniques may be measured. (author)

Variation in Adherence to External Beam Radiotherapy Quality Measures Among Elderly Men With Localized Prostate Cancer

International Nuclear Information System (INIS)

Bekelman, Justin E.; Zelefsky, Michael J.; Jang, Thomas L.; Basch, Ethan M.; Schrag, Deborah

2007-01-01

Purpose: To characterize the variation in adherence to quality measures of external beam radiotherapy (EBRT) for localized prostate cancer and its relation to patient and provider characteristics in a population-based, representative sample of U.S. men. Methods and Materials: We evaluated EBRT quality measures proposed by a RAND expert panel of physicians among men aged ≥65 years diagnosed between 2000 and 2002 with localized prostate cancer and treated with primary EBRT using data from the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare program. We assessed the adherence to five EBRT quality measures that were amenable to analysis using SEER-Medicare data: (1) use of conformal RT planning; (2) use of high-energy (>10-MV) photons; (3) use of custom immobilization; (4) completion of two follow-up visits with a radiation oncologist in the year after therapy; and (5) radiation oncologist board certification. Results: Of the 11,674 patients, 85% had received conformal RT planning, 75% had received high-energy photons, and 97% had received custom immobilization. One-third of patients had completed two follow-up visits with a radiation oncologist, although 91% had at least one visit with a urologist or radiation oncologist. Most patients (85%) had been treated by a board-certified radiation oncologist. Conclusions: The overall high adherence to EBRT quality measures masked substantial variation in geography, socioeconomic status in the area of residence, and teaching affiliation of the RT facility. Future research should examine the reasons for the variations in these measures and whether the variation is associated with important clinical outcomes

A Preliminary Design Of Application Of Wireless Identification And Sensing Platform On External Beam Radiotherapy

Science.gov (United States)

Heranudin; Bakhri, S.

2018-02-01

A linear accelerator (linac) is widely used as a means of radiotherapy by focusing high-energy photons in the targeted tumor of patient. Incorrectness of the shooting can lead normal tissue surrounding the tumor received unnecessary radiation and become damaged cells. A method is required to minimize the incorrectness that mostly caused by movement of the patient during radiotherapy process. In this paper, the Wireless Identification and Sensing Platform (WISP) architecture was employed to monitor in real time the movement of the patient’s body during radiotherapy process. In general, the WISP is a wearable sensors device that can transmit measurement data wirelessly. In this design, the measurement devices consist of an accelerometer, a barometer and an ionizing radiation sensor. If any changes in the body position which resulted in incorrectness of the shooting, the accelerometer and the barometer will trigger a warning to the linac operator. In addition, the radiation sensor in the WISP will detect unwanted radiation and that can endanger the patient. A wireless feature in this device can ease in implementation. Initial analyses have been performed and showed that the WISP is feasible to be applied on external beam radiotherapy.

Complete response in a patient with gynecological hidradenocarcinoma treated with exclusive external beam radiotherapy and brachytherapy: a case report.

Science.gov (United States)

Giannelli, Flavio; Chiola, Ilaria; Belgioia, Liliana; Garelli, Stefania; Pastorino, Alice; Marcenaro, Michela; Mammoliti, Serafina; Costantini, Sergio; Bizzarri, Nicolò; Vellone, Valerio; Barra, Salvina; Corvò, Renzo

2017-12-01

Hidradenocarcinoma (HC) is a very rare disease. This case report illustrates a successful treatment of a 60-year-old woman with vulvo-vaginal localization of hidradenocarcinoma treated with external beam radiotherapy delivered by helical tomotherapy with a simultaneous integrated boost (SIB), followed by brachytherapy. External beam radiotherapy dose prescription was 50.4 Gy in 28 fractions, five fractions per week to whole pelvis (planning target volume 1 - PTV1), 60.2 Gy in 28 fractions to SIB1 (fundus of uterus and right inguinal node), and 58.8 Gy in 28 fractions to SIB2 (lower/middle third of vagina, paraurethral region and right inguinal lymph nodes). Brachytherapy dose prescription was 28 Gy in 4 fractions for cervix, fundus of uterus and upper third of vagina (HR-CTV1), and 22 Gy in 4 fractions to middle third of vagina and paraurethral region (HR-CTV2). D 90 for whole treatment was 91.9 Gy and 86.0 Gy for HR-CTV1 and HR-CTV2, respectively. Patient remained 12-months disease-free without treatment related side effects.

Complete response in a patient with gynecological hidradenocarcinoma treated with exclusive external beam radiotherapy and brachytherapy: a case report

Directory of Open Access Journals (Sweden)

Flavio Giannelli

2017-12-01

Full Text Available Hidradenocarcinoma (HC is a very rare disease. This case report illustrates a successful treatment of a 60-year-old woman with vulvo-vaginal localization of hidradenocarcinoma treated with external beam radiotherapy delivered by helical tomotherapy with a simultaneous integrated boost (SIB, followed by brachytherapy. External beam radiotherapy dose prescription was 50.4 Gy in 28 fractions, five fractions per week to whole pelvis (planning target volume 1 – PTV1, 60.2 Gy in 28 fractions to SIB1 (fundus of uterus and right inguinal node, and 58.8 Gy in 28 fractions to SIB2 (lower/middle third of vagina, paraurethral region and right inguinal lymph nodes. Brachytherapy dose prescription was 28 Gy in 4 fractions for cervix, fundus of uterus and upper third of vagina (HR-CTV1, and 22 Gy in 4 fractions to middle third of vagina and paraurethral region (HR-CTV2. D90 for whole treatment was 91.9 Gy and 86.0 Gy for HR-CTV1 and HR-CTV2, respectively. Patient remained 12-months disease-free without treatment related side effects.

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.

The Outcome of Conventional External Beam Radiotherapy for Patients with Squamous Cell Carcinoma of the Esophagus

International Nuclear Information System (INIS)

Jang, Ji Young

2008-01-01

The best treatment for advanced esophageal cancer is chemoradiotherapy followed by surgery. In spite of the advance of multimodality therapy, most patients with esophageal cancer are treated with radiation therapy alone. This study reports the outcome of the use of conventional external beam radiotherapy alone for the treatment of esophageal cancer. Between January 1998 and December 2005, 30 patients with squamous cell carcinoma of the esophagus were treated with external beam radiotherapy using a total dose exceeding 40 Gy. Radiotherapy was delivered with a total dose of 44-60 Gy (median dose, 57.2 Gy) over 36 ∼115 days (median time, 45 days). Thirteen patients (43.3%) had a history of disorders such as diabetes, hypertension, tuberculosis, lye stricture, asthma, cerebral infarct, and cancers. Four patients metachronously had double primary cancers. The most common location of a tumor was the mid-thoracic portion of the esophagus (56.7%). Tumor lengths ranged from 2 cm to 11 cm, with a median length of 6 cm. For AJCC staging, stage III was the most common (63.3%). Five patients had metastases at diagnosis. The median overall survival was 8.3 months. The survival rates at 1-year and 2-years were 33.3% and 18.7%, respectively. The complete response rate 1∼3 months after radiotherapy was 20% (6/30) and the partial response rate was 70% (21/30). Sixteen patients (53.3%) had an improved symptom of dysphagia. Significant prognostic factors were age, tumor length, stage, degree of dysphagia at the time of diagnosis and tumor response. Cox regression analysis revealed the aim of treatment, clinical tumor response and tumor length as independent prognostic factors for overall survival. Twenty-eight patients had local failure and another four patients had metastases. Three patients were detected with double primary cancers in this analysis. A complication of esophageal stricture was observed in three patients (10%), and radiation pneumonitis occurred in two patients (6

The Outcome of Conventional External Beam Radiotherapy for Patients with Squamous Cell Carcinoma of the Esophagus

Energy Technology Data Exchange (ETDEWEB)

Jang, Ji Young [Chosun University College of Medicine, Gwangju (Korea, Republic of)

2008-03-15

The best treatment for advanced esophageal cancer is chemoradiotherapy followed by surgery. In spite of the advance of multimodality therapy, most patients with esophageal cancer are treated with radiation therapy alone. This study reports the outcome of the use of conventional external beam radiotherapy alone for the treatment of esophageal cancer. Between January 1998 and December 2005, 30 patients with squamous cell carcinoma of the esophagus were treated with external beam radiotherapy using a total dose exceeding 40 Gy. Radiotherapy was delivered with a total dose of 44-60 Gy (median dose, 57.2 Gy) over 36 {approx}115 days (median time, 45 days). Thirteen patients (43.3%) had a history of disorders such as diabetes, hypertension, tuberculosis, lye stricture, asthma, cerebral infarct, and cancers. Four patients metachronously had double primary cancers. The most common location of a tumor was the mid-thoracic portion of the esophagus (56.7%). Tumor lengths ranged from 2 cm to 11 cm, with a median length of 6 cm. For AJCC staging, stage III was the most common (63.3%). Five patients had metastases at diagnosis. The median overall survival was 8.3 months. The survival rates at 1-year and 2-years were 33.3% and 18.7%, respectively. The complete response rate 1{approx}3 months after radiotherapy was 20% (6/30) and the partial response rate was 70% (21/30). Sixteen patients (53.3%) had an improved symptom of dysphagia. Significant prognostic factors were age, tumor length, stage, degree of dysphagia at the time of diagnosis and tumor response. Cox regression analysis revealed the aim of treatment, clinical tumor response and tumor length as independent prognostic factors for overall survival. Twenty-eight patients had local failure and another four patients had metastases. Three patients were detected with double primary cancers in this analysis. A complication of esophageal stricture was observed in three patients (10%), and radiation pneumonitis occurred in two

Differentiated Thyroid Cancer with Extrathyroidal Extension: Prognosis and the Role of External Beam Radiotherapy

Directory of Open Access Journals (Sweden)

Michael A. Sia

2010-01-01

Full Text Available A study was performed to identify variables that affected cause-specific survival (CSS and local relapse-free rate (LRFR in patients with differentiated thyroid cancer (DTC and extrathyroid extension (ETE and to examine the role of external beam radiotherapy (XRT. Prognostic factors were similar to those found in studies of all patients with DTC. In patients with postoperative gross residual disease treated with radiotherapy, 10-year CSS and LRFR were 48% and 90%. For patients with no residual or microscopic disease, 10-year CSS and LRFR were 92% and 93%. In patients older than 60 years with T3 ETE but no gross residual disease postoperatively there was an improved LRFR at 5 years of 96%, compared to 87.5% without XRT (P=.02. Patients with gross ETE benefit from XRT and there may be a potential benefit in reducing locoregional failure in patients over 60 years with minimal extrathyroidal extension (T3.

Radiation safety assessment of cobalt 60 external beam radiotherapy using the risk-matrix method

International Nuclear Information System (INIS)

Dumenigo, C; Vilaragut, J.J.; Ferro, R.; Guillen, A.; Ramirez, M.L.; Ortiz Lopez, P.; Rodriguez, M.; McDonnell, J.D.; Papadopulos, S.; Pereira, P.P.; Goncalvez, M.; Morales, J.; Larrinaga, E.; Lopez Morones, R.; Sanchez, R.; Delgado, J.M.; Sanchez, C.; Somoano, F.

2008-01-01

External beam radiotherapy is the only practice in which humans are placed directly in a radiation beam with the intention to deliver a very high dose. This is why safety in radiotherapy is very critical, and is a matter of interest to both radiotherapy departments and regulatory bodies. Accidental exposures have occurred throughout the world, thus showing the need for systematic safety assessments, capable to identify preventive measures and to minimize consequences of accidental exposure. Risk-matrix is a systematic approach which combines the relevant event features to assess the overall risk of each particular event. Once an event sequence is identified, questions such as how frequent the event, how severe the potential consequences and how reliable the existing safety measures are answered in a risk-matrix table. The ultimate goal is to achieve that the overall risk for events with severe consequences should always be low o very low. In the present study, the risk-matrix method has been applied to an hypothetical radiotherapy department, which could be equivalent to an upper level hospital of the Ibero American region, in terms of safety checks and preventive measures. The application of the method has identified 76 event sequences and revealed that the hypothetical radiotherapy department is sufficiently protected (low risk) against them, including 23 event sequences with severe consequences. The method has revealed that the risk of these sequences could grow to high level if certain specific preventive measures were degraded with time. This study has identified these preventive measures, thus facilitating a rational allocation of resources in regular controls to detect any loss of reliability. The method has proven to have an important practical value and is affordable at hospital level. The elaborated risk-matrix can be easily adapted to local circumstances, in terms of existing controls and safety measures. This approach can help hospitals to identify

External beam radiotherapy for head and neck carcinomas with preservation of parotid function: indications, techniques and long term results

International Nuclear Information System (INIS)

Ding-Jen, Lee; Fairbanks, Robert; Lee, Frank C.

1995-01-01

Purpose/Objective: To reduce the incidence of radiotherapy induced xerostomia, we developed techniques of external beam irradiation with preservation of parotid function for patients with early to intermediate stage carcinomas of the head and neck. This analysis reports the efficacy of our methods. Materials and Methods: From 1985 to 1993, 42 patients with early to intermediate stage (T 1-3 N 0-2 M 0 ) head and neck carcinomas received a course of external beam radiotherapy. There were 13 patients with carcinoma of the oropharynx, 26 with carcinomas of the oral cavity and 3 with carcinomas of the hypopharynx (lateral wall). 7 patients received a course of definitive radiotherapy (66 to 72 Gy), while 35 patients received a course of postoperative radiotherapy (60-66 Gy). The fraction size was 2 Gy per day. In terms of treatment planning, the primary site (plus a margin) and the ipsilateral neck were covered by the irradiation volume. The ipsilateral parotid gland was within the treatment volume while the contralateral parotid gland was not. The most frequently used field arrangement was a paired wedge fields with an AP (medially just across the mid-line) and an ipsilateral posterior oblique field (usually 30 deg. off vertical axis with a spinal cord block). Multiple level of contours were taken and transmission blocks were used to improve dose homogeneity. In all patients, the ipsilateral parotid gland (and the neck) was irradiated while the contralateral parotid gland (and the neck) was not. Results: With a median follow up of 4 years (ranged from 1.5 to 9 years), only one patient developed symptomatic xerostomia. None had radiation induced dental caries. No patient developed recurrent disease in the contralateral neck. The local control rate was (38(42)) (90%) in the primary site and(41(42)) (98%) in the ipsilateral neck. Conclusion: With appropriate treatment planning, external beam irradiation with parotid function preservation can be achieved. Our results

A deterministic iterative least-squares algorithm for beam weight optimization in conformal radiotherapy

International Nuclear Information System (INIS)

Chen Yan; Michalski, Darek; Houser, Christopher; Galvin, James M.

2002-01-01

Currently, inverse treatment planning in conformal radiotherapy is, in part, a trial-and-error process due to the interplay of many competing criteria for obtaining a clinically acceptable dose distribution. A new method is developed for beam weight optimization that incorporates clinically relevant nonlinear and linear constraints. The process is driven by a nonlinear, quasi-quadratic objective function and the solution space is defined by a set of linear constraints. At each step of iteration, the optimization problem is linearized by a self-consistent approximation that is local to the existing dose distribution. The dose distribution is then improved by solving a series of constrained least-squares problems using an established method until all prescribed constraints are satisfied. This differs from the current approaches in that it does not rely on the search for the global minimum of a specific objective function. Essentially, our proposed objective function can be construed as a functional that comprises a class of dose-based quadratic objective functions. Empirical adjustment for appropriate model parameters in the construction of objective function is minimized, since these parameters are in effect adaptively adjusted during optimization. The method is robust in solving difficult clinical cases using either aperture or pencil beam based planning techniques for intensity-modulated radiation therapy. (author)

Initiation of conformal radiotherapy with a multileaf-collimator - An approach to clinical routine

International Nuclear Information System (INIS)

Bannach, B.; Doll, Th.; Pape, H.; Schmitt, G.

1995-01-01

The implementation of a three-dimensional conformal radiotherapy facility in the radiotherapy department of the Heinrich Heine University is described. Complex radiotherapy techniques with commercially available networked systems are introduced to improve clinical work. Over 18 month we have gained clinical experience with a PHILIPS Multileaf Collimator (MLC) mounted on a SL 25 linear accelerator. For a limited period the MLC was used as a conventional blocking device. The standard MLC-shapes are controlled with a stand-alone computer system. In addition, a three-dimensional treatment planning system (3-D-TPS / TMS-Radix, Helax AB) based on convolution/superposition algorithms was recently installed. Treatment optimization is achieved using static field arrangements with complete volumetric computerized tomographic patient data for 3-D-TPS. Conformal adaptation of the 95%-isodose to the Planning Target Volume (PTV, ICRU 50) results in MLC-field-shaping concerning size, position and contour to PTV-projection in beams-eye-view (BEV). Field prescription with defined leaf positions of the MLC-setting for geometrical beam shaping is transferred from TPS via TCP/IP. Patient treatment with complex coplanar and non-coplanar field arrangements is performed with an automatic set-up for gantry and collimator angle position contolled by a verification system. Quality assurance for treatment set-up is gained with a mega-voltage imaging device (MVI / PHILIPS SRI 100). Actual treatment outcome and accurate dose delivery for conformal therapy is verified by intercomparison of geometrical field matching of MVI and digitally reconstructed radiographs (DRR) for each delivered beam in BEV

External beam radiotherapy dose response characteristics of 1127 men with prostate cancer treated in the PSA era

International Nuclear Information System (INIS)

Pollack, Alan; Smith, Lewis G.; Eschenbach, Andrew C. von

2000-01-01

Purpose: To characterize the relationship of radiotherapy dose to prostate cancer patient outcome, with an emphasis on the influence of pretreatment prognostic variables. Methods and Materials: The 1127 Stage T1-T4 prostate cancer patients examined were treated consecutively with definitive external beam radiotherapy at the University of Texas-M.D. Anderson Cancer Center from 1987 to 1997. All had a pretreatment prostate-specific antigen (PSA) level. Treatment failure was defined as two consecutive PSA elevations on follow-up. There were 994 patients treated with a four-field box throughout to 60-70 Gy after a small reduction at 46 Gy and 161 treated with a six-field conformal boost after 46 Gy to 74-78 Gy. No patient received neoadjuvant or adjuvant androgen ablation. Median follow-up was 51.8 months. Results: Patients were divided into three radiotherapy dose groups consisting of ≤67 Gy (n = 500), >67-77 Gy (n = 495), and >77 Gy (n = 132). Relative to other prognostic factors, there were fewer patients treated to the highest dose level with a pretreatment PSA (PSAB) ≤4 or >20 ng/ml, Stage T3/T4 disease, or a Gleason score of 2-6. Actuarial 4-year freedom from biochemical failure (bNED) rates for the entire cohort were 54%, 71%, and 77% (p 67-77 Gy was associated with improved bNED rates for all PSAB (≤10 and >10), stage (T1/T2 and T3/T4), and Gleason score (2-6 and 7-10) subgroups tested. In contrast, the only prognostic group that benefited from raising dose from >67-77 Gy to >77 Gy was patients with a PSAB >10 ng/ml; although trends were noted for Stage T1/T2 and Gleason 2-6 patients. Patients with the combined features of a PSAB >10 ng/ml and Stage T1/T2 disease had 4-year bNED rates of 61% and 93% at the intermediate- and high-dose levels. A strongly significant linear association between dose (60-78 Gy) and 4-year actuarial bNED was demonstrated for patients with these intermediate-risk features. Conclusion: Prostate cancer dose response to external

Phase I study of twice-weekly gemcitabine and concomitant external-beam radiotherapy in patients with adenocarcinoma of the pancreas

International Nuclear Information System (INIS)

Pipas, J. Marc; Mitchell, Sandra E.; Barth, Richard J.; Vera-Gimon, Raul; Rathmann, Joerg; Meyer, Louise P.; Wagman, Richard S.; Lewis, Lionel D.; McDonnell, Carol; Colacchio, Thomas A.; Perez, Raymond P.

2001-01-01

Purpose: To determine the maximum tolerated dose and dose-limiting toxicity associated with twice-weekly gemcitabine and concomitant external-beam radiotherapy in patients with adenocarcinoma of the pancreas. Methods and Materials: Twenty-one patients with biopsy-proven adenocarcinoma of the pancreas were treated with external-beam radiotherapy to a dose of 50.4 Gy in 28 fractions, concurrent with gemcitabine, infused over 30 min before irradiation on a Monday and Thursday schedule. The dose of gemcitabine was escalated in 5 cohorts of 3-6 patients each. Initial gemcitabine dose was 10 mg/m 2 , with dose escalation until dose-limiting toxicity was observed. Results: The maximum tolerated dose of gemcitabine was 50 mg/m 2 , when given in a twice-weekly schedule with radiation. Dose-limiting toxicity was seen in 2 patients at 60 mg/m 2 , and consisted of severe upper gastrointestinal bleeding approximately 1 month after completion of treatment. Six patients had radiographic evidence of response to treatment, and 5 of these underwent complete surgical resection. Three patients who underwent complete resection had been deemed to have unresectable tumors before enrollment on trial. Four patients are alive, including 2 without evidence of disease more than 1 year after resection. Conclusion: The combination of external-beam radiation and twice-weekly gemcitabine at a dose of 50 mg/m 2 is well tolerated and shows promising activity for the treatment of pancreatic cancer. Our data suggest a higher maximum tolerated dose and different dose-limiting toxicity than previously reported. Further investigation of this regimen is warranted

Beam angle selection for intensity-modulated radiotherapy (IMRT) treatment of unresectable pancreatic cancer: are noncoplanar beam angles necessary?

Science.gov (United States)

Chang, D S; Bartlett, G K; Das, I J; Cardenes, H R

2013-09-01

External beam radiation therapy with concurrent chemotherapy (CRT) is widely used for the treatment of unresectable pancreatic cancer. Noncoplanar (NCP) 3D conformal radiotherapy (3DCRT) and coplanar (CP) IMRT have been reported to lower the radiation dose to organs at risk (OARs). The purpose of this article is to examine the utility of noncoplanar beam angles in IMRT for the management of pancreatic cancer. Sixteen patients who were treated with CRT for unresectable adenocarcinoma of the pancreatic head or neck were re-planned using CP and NCP beams in 3DCRT and IMRT with the Varian Eclipse treatment planning system. Compared to CP IMRT, NCP IMRT had similar target coverage with slightly increased maximum point dose, 5,799 versus 5,775 cGy (p = 0.008). NCP IMRT resulted in lower mean kidney dose, 787 versus 1,210 cGy (p kidney dose, but did not improve other dose-volume criteria. The use of NCP beam angles is preferred only in patients with risk factors for treatment-related kidney dysfunction.

A Phase II study of external-beam radiotherapy and endovascular brachytherapy with PTA and stenting for femoropopliteal artery restenosis

International Nuclear Information System (INIS)

Narayan, Kailash; Denton, Michael; Das, Ram; Bernshaw, David; Rolfo, Aldo; Dyk, Sylvia van; Mirakian, Alex

2006-01-01

Purpose: To assess the safety and seek evidence of efficacy of combined external-beam radiotherapy (EBRT) and endovascular brachytherapy in the treatment of stenotic vascular lesions. Methods and Materials: Seventeen patients with high risk for restenosis of femoropopliteal arteries were enrolled in this study from February 2000 to August 2002. The external beam radiotherapy regimen consisted of 10 Gy in 5 fractions of 2 Gy, starting on Day 0. This was followed on Day 6 by angiography, stent placement, and intraluminal brachytherapy to a dose of 10 Gy at 1.2 mm from stent surface. The EBRT was continued from the same day to another 10 Gy in 2 Gy daily fractions for 5 days. Results: The follow up ranged from 33 months to 60 months. At the time of analysis 15 of 17 patients were alive with patent stents. Of these, 10 were symptom-free. Two patients died of unrelated causes. Conclusions: The combination of EBRT and endovascular brachytherapy provided adequate dose distribution without any geographical miss or 'candy wrapper' restenosis. No incidence of aneurysmal dilation of radiated vascular segment was observed. The treatment was feasible, well tolerated, and achieved 88% stenosis free survival

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)

A digital fluoroscopic imaging system for verification during external beam radiotherapy

International Nuclear Information System (INIS)

Takai, Michikatsu

1990-01-01

A digital fluoroscopic (DF) imaging system has been constructed to obtain portal images for verification during external beam radiotherapy. The imaging device consists of a fluorescent screen viewed by a highly sensitive video camera through a mirror. The video signal is digitized and processed by an image processor which is linked on-line with a host microcomputer. The image quality of the DF system was compared with that of film for portal images of the Burger phantom and the Alderson anthropomorphic phantom using 10 MV X-rays. Contrast resolution of the DF image integrated for 8.5 sec. was superior to the film resolution, while spatial resolution was slightly inferior. The DF image of the Alderson phantom processed by the adaptive histogram equalization was better in showing anatomical landmarks than the film portal image. The DF image integrated for 1 sec. which is used for movie mode can show patient movement during treatment. (author)

Fractionated stereotactic conformal radiotherapy following conservative surgery in the control of craniopharyngiomas

International Nuclear Information System (INIS)

Minniti, Giuseppe; Saran, Frank; Traish, Daphne; Soomal, Rubin; Sardell, Susan; Gonsalves, Adam; Ashley, Susan; Warrington, Jim; Burke, Kevin; Mosleh-Shirazi, Amin; Brada, Michael

2007-01-01

Purpose: To describe the technique and results of stereotactically guided conformal radiotherapy (SCRT) in patients with craniopharyngioma after conservative surgery. Methods and materials: Thirty-nine patients with craniopharyngioma aged 3-68 years (median age 18 years) were treated with SCRT between June 1994 and January 2003. All patients were referred for radiotherapy after undergoing one or more surgical procedures. Treatment was delivered in 30-33 daily fractions over 6-6.5 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively. Results: At a median follow-up of 40 months (range 3-88 months) the 3- and 5-year progression-free survival (PFS) was 97% and 92%, and 3- and 5-year survival 100%. Two patients required further debulking surgery for progressive disease 8 and 41 months after radiotherapy. Twelve patients (30%) had acute clinical deterioration due to cystic enlargement of craniopharyngioma following SCRT and required cyst aspiration. One patient with severe visual impairment prior to radiotherapy had visual deterioration following SCRT. Seven out of 10 patients with a normal pituitary function before SCRT had no endocrine deficits following treatment. Conclusion: SCRT as a high-precision technique of localized RT is suitable for the treatment of incompletely excised craniopharyngioma. The local control, toxicity and survival outcomes are comparable to results reported following conventional external beam RT. Longer follow-up is required to assess long-term efficacy and toxicity, particularly in terms of potential reduction in treatment related late toxicity

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.)

A comparison of protocols for external beam radiotherapy beam calibrations

International Nuclear Information System (INIS)

Saeed Al-Ahbabi, Salma; Bradley, D.A.; Beyomi, M.; Alkatib, Z.; Adhaheri, S.; Darmaki, M.; Nisbet, A.

2012-01-01

A number of codes of practice (CoP) for electron and photon radiotherapy beam dosimetry are currently in use. Comparison is made of the more widely used of these, specifically those of the International Atomic Energy Agency (IAEA TRS-398), the American Association of Physicists in Medicine (AAPM TG-51) and the Institute of Physics and Engineering in Medicine (IPEM 2003). All are based on calibration of ionization chambers in terms of absorbed dose to water, each seeking to reduce uncertainty in delivered dose, providing an even stronger system of primary standards than previous air-kerma based approaches. They also provide a firm, traceable and straight-forward formalism. Included in making dose assessments for the three CoP are calibration coefficients for a range of beam quality indices. Measurements have been performed using clinical photon and electron beams, the absorbed dose to water being obtained following the recommendations given by each code. Electron beam comparisons have been carried out using measurements for electron beams of nominal energies 6, 9, 12, 16 and 20 MeV. Comparisons were also carried out for photon beams of nominal energies 6 and 18 MV. For photon beams use was made of NE2571 cylindrical graphite walled ionization chambers, cross-calibrated against an NE2611 Secondary Standard; for electron beams, PTW Markus and NACP-02 plane-parallel chambers were used. Irradiations were made using Varian 600C/2100C linacs, supported by water tanks and Virtual Water™ phantoms. The absorbed doses for photon and electron beams obtained following these CoP are all in good agreement, with deviations of less than 2%. A number of studies have been carried out by different groups in different countries to examine the consistency of dosimetry codes of practice or protocols. The aim of these studies is to confirm that the goal of those codes is met, namely uniformity in establishment of dosimetry of all radiation beam types used in cancer therapy in the world

Absorbed dose determination in external beam radiotherapy. An international code of practice for dosimetry based on standards of absorbed dose to water

International Nuclear Information System (INIS)

2000-01-01

The International Atomic Energy Agency published in 1987 an International Code of Practice entitled 'Absorbed Dose Determination in Photon and Electron Beams' (IAEA Technical Reports Series No. 277 (TRS-277)), recommending procedures to obtain the absorbed dose in water from measurements made with an ionization chamber in external beam radiotherapy. A second edition of TRS-277 was published in 1997 updating the dosimetry of photon beams, mainly kilovoltage X rays. Another International Code of Practice for radiotherapy dosimetry entitled 'The Use of Plane-Parallel Ionization Chambers in High Energy Electron and Photon Beams' (IAEA Technical Reports Series No. 381 (TRS-381)) was published in 1997 to further update TRS-277 and complement it with respect to the area of parallel-plate ionization chambers. Both codes have proven extremely valuable for users involved in the dosimetry of the radiation beams used in radiotherapy. In TRS-277 the calibration of the ionization chambers was based on primary standards of air kerma; this procedure was also used in TRS-381, but the new trend of calibrating ionization chambers directly in a water phantom in terms of absorbed dose to water was introduced. The development of primary standards of absorbed dose to water for high energy photon and electron beams, and improvements in radiation dosimetry concepts, offer the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. The dosimetry of kilovoltage X rays, as well as that of proton and heavy ion beams, interest in which has grown considerably in recent years, can also be based on these standards. Thus a coherent dosimetry system based on standards of absorbed dose to water is possible for practically all radiotherapy beams. Many Primary Standard Dosimetry Laboratories (PSDLs) already provide calibrations in terms of absorbed dose to water at the radiation quality of 60 Co gamma rays. Some laboratories have extended calibrations to high energy photon and

Urinary incontinence in prostate cancer patients treated with external beam radiotherapy

International Nuclear Information System (INIS)

Liu, Mitchell; Pickles, Tom; Berthelet, Eric; Agranovich, Alexander; Kwan, Winkle; Tyldesley, Scott; McKenzie, Michael; Keyes, Mira; Morris, James; Pai, Howard

2005-01-01

Background and purpose: To describe the incidence of urinary incontinence among prostate cancer patients treated with external beam radiotherapy (RT) and to investigate associated risk factors. Patients and methods: One thousand and hundred ninety-two patients with ≥24 months follow-up were the subjects of this series. All patients received between 50 and 72 Gy in 20-37 fractions (median 66 Gy/33). Post-RT urinary incontinence was scored by direct patient interviewing according to the modified RTOG/SOMA scale: Grade 1-occasional use of incontinence pads, Grade 2-intermittent use of incontinence pads, Grade 3-persistent use of incontinence pads, and Grade 4-permanent catheter. Risk-factors investigated were: age, diabetes, TURP prior to RT, elapsed time from TURP to RT, clinical stage, RT dose and presence of Grade ≥2 acute GU and GI toxicity. Non-parametric, actuarial univariate (Kaplan-Meier) and multivariate tests (MVA, Cox regression) were performed. Results: Median follow-up for the group is 52 months (24-109). Thirty-four patients (2.9%) had incontinence prior to RT, which was more common in TURP patients (7.8% vs 1.6% P<0.001). These are excluded from further analysis. Fifty-seven patients (4.9%) developed Grade 1 incontinence, 7 (0.6%) Grade 2, and 7 (0.6%) Grade 3. There was no Grade 4 incontinence. Actuarial rates for Grade ≥1 and ≥2 incontinence at 5 years are 7 and 1.7%, respectively. Risk factors on MVA associated with the development of Grade 1 or worse incontinence are pre-RT TURP (5-year rates 10% vs 6%, P=0.026), presence of Grade ≥2 acute GU toxicity (5-year rates 11% vs 5%, P=0.002). Age, diabetes, clinical stage, elapsed time from TURP to RT, RT dose or fraction size, acute GI toxicity were not significant. Patients who underwent post-RT TURP or dilatation for obstructive symptoms (4.3%), were more likely to develop Grade 2-3 incontinence (5-year rate 8 vs 1.5%, P=0.0015). Conclusions: Grade 2 or greater urinary incontinence is rare

Implementation of a system for external audits beam radiation therapy in terms of reference no

International Nuclear Information System (INIS)

Alonso Samper, Jose Luis; Dominguez, Lourdes; Alert Silva, Jose; Alfonso Laguardia, Rodolfo; Larrinaga Cortina, Eduardo; Garcia Yip, Fernando; Rodriguez Machado, Jorge; Morales Lopez, Jorge Luis; Silvestre Patallo, Ileana

2009-01-01

This paper presents our experience in implementing a external audit system for radiotherapy beam in no reference conditions with the use of CIRS and a summary of the measurements with him made.This paper presents our experience in implementing a external audit system for radiotherapy beam in no reference conditions with the use of CIRS and a summary of the measurements with him made. Centers were audited with external beam high-energy Co-60, 6 MV and 15 MV and were considered 4 treatment planning systems (TPS): AMEPLAN, Theraplan Plus, Precise Plan and MIRS to calculate doses prescribed in each test case. All measurements were acquired by the audit team using the anthropomorphic phantom CIRS, Semiflex chamber PTW 31010 and PTW electrometer STATES. The implementation and development of the external audits of beams radiotherapy in terms of 'no reference' has brought an improvement in both clinical aspects of treatment and the radiation safety and the quality control, has given us greater confidence and for this reason we believe has become essential. (Author)

Beam related response of in vivo diode detectors for external radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Baci, Syrja, E-mail: sbarci2013@gmail.com [Department of Physics, Faculty of Natural Sciences, University of Gjirokastra, “Eqrem Çabej” (Albania); Telhaj, Ervis [Department of Medical Physics, Hygeia Hospital Tirana (Albania); Malkaj, Partizan [Department of Physical Engineering, Polytechnic University, Tirana (Albania)

2016-03-25

In Vivo Dosimetry (IVD) is a set of methods used in cancer treatment clinics to determine the real dose of radiation absorbed by target volume in a patient’s body. IVD has been widely implemented in radiotherapy treatment centers and is now recommended part of Quality Assurance program by many International health and radiation organizations. Because of cost and lack of specialized personnel, IVD has not been practiced as yet, in Albanian radiotherapy clinics. At Hygeia Hospital Tirana, patients are irradiated with high energy photons generated by Elekta Synergy Accelerators. We have recently started experimenting with the purpose of establishing an IVD practice at this hospital. The first set of experiments was aimed at calibration of diodes that are going to be used for IVD. PMMA, phantoms by PTW were used to calibrate p – type Si, semiconductor diode dosimeters, made by PTW Freiburg for entrance dose. Response of the detectors is affected by energy of the beam, accumulated radiation dose, dose rate, temperature, angle against the beam axis, etc. Here we present the work done for calculating calibration factor and correction factors of source to surface distance, field size, and beam incidence for the entrance dose for both 6 MV photon beam and 18 MV photon beam. Dependence of dosimeter response was found to be more pronounced with source to surface distance as compared to other variables investigated.

Beam related response of in vivo diode detectors for external radiotherapy

International Nuclear Information System (INIS)

Baci, Syrja; Telhaj, Ervis; Malkaj, Partizan

2016-01-01

In Vivo Dosimetry (IVD) is a set of methods used in cancer treatment clinics to determine the real dose of radiation absorbed by target volume in a patient’s body. IVD has been widely implemented in radiotherapy treatment centers and is now recommended part of Quality Assurance program by many International health and radiation organizations. Because of cost and lack of specialized personnel, IVD has not been practiced as yet, in Albanian radiotherapy clinics. At Hygeia Hospital Tirana, patients are irradiated with high energy photons generated by Elekta Synergy Accelerators. We have recently started experimenting with the purpose of establishing an IVD practice at this hospital. The first set of experiments was aimed at calibration of diodes that are going to be used for IVD. PMMA, phantoms by PTW were used to calibrate p – type Si, semiconductor diode dosimeters, made by PTW Freiburg for entrance dose. Response of the detectors is affected by energy of the beam, accumulated radiation dose, dose rate, temperature, angle against the beam axis, etc. Here we present the work done for calculating calibration factor and correction factors of source to surface distance, field size, and beam incidence for the entrance dose for both 6 MV photon beam and 18 MV photon beam. Dependence of dosimeter response was found to be more pronounced with source to surface distance as compared to other variables investigated.

Radical external beam radiotherapy for prostate cancer in Japan. Differences in the patterns of care between Japan and the United States

International Nuclear Information System (INIS)

Ogawa, Kazuhiko; Nakamura, Katsumasa; Sasaki, Tomonari; Onishi, Hiroshi; Araya, Masayuki; Koizumi, Masahiko; Okamoto, Atsushi; Tejima, Teruki; Mitsumori, Michihide

2007-01-01

This study focused on the differences in the patterns of care for prostate cancer patients treated with radical external beam radiotherapy between Japan and the United States. Results from the 1999-2001 Japanese Patterns of Care Study (PCS) survey were compared with those of the 1999 PCS in the United States. In addition, the changing trends in the patterns of care between Japan and the United States were also analyzed. Patients in Japan were found to have more advanced primary disease than those in the United States, but the proportions of advanced disease have gradually decreased in Japan. The distributions of CT-based treatment planning, conformal therapy and higher doses were higher in the United States, and a drastic change in these parameters occurred in the United States, while only moderate changes occurred in Japan. These results indicate that patterns of care for prostate cancer in Japan are considerably different from those in the United States, and the changing trends in the patterns of care are also different between the two countries. (author)

An ill-conditioning conformal radiotherapy analysis based on singular values decomposition

International Nuclear Information System (INIS)

Lefkopoulos, D.; Grandjean, P.; Bendada, S.; Dominique, C.; Platoni, K.; Schlienger, M.

1995-01-01

Clinical experience in stereotactic radiotherapy of irregular complex lesions had shown that optimization algorithms were necessary to improve the dose distribution. We have developed a general optimization procedure which can be applied to different conformal irradiation techniques. In this presentation this procedure is tested on the stereotactic radiotherapy modality of complex cerebral lesions treated with multi-isocentric technique based on the 'associated targets methodology'. In this inverse procedure we use the singular value decomposition (SVD) analysis which proposes several optimal solutions for the narrow beams weights of each isocentre. The SVD analysis quantifies the ill-conditioning of the dosimetric calculation of the stereotactic irradiation, using the condition number which is the ratio of the bigger to smaller singular values. Our dose distribution optimization approach consists on the study of the irradiation parameters influence on the stereotactic radiotherapy inverse problem. The adjustment of the different irradiation parameters into the 'SVD optimizer' procedure is realized taking into account the ratio of the quality reconstruction to the time calculation. It will permit a more efficient use of the 'SVD optimizer' in clinical applications for real 3D lesions. The evaluation criteria for the choice of satisfactory solutions are based on the dose-volume histograms and clinical considerations. We will present the efficiency of ''SVD optimizer'' to analyze and predict the ill-conditioning in stereotactic radiotherapy and to recognize the topography of the different beams in order to create optimal reconstructed weighting vector. The planification of stereotactic treatments using the ''SVD optimizer'' is examined for mono-isocentrically and complex dual-isocentrically treated lesions. The application of the SVD optimization technique provides conformal dose distribution for complex intracranial lesions. It is a general optimization procedure

Potential for enhancing external beam radiotherapy for lung cancer using high-Z nanoparticles administered via inhalation

Science.gov (United States)

Hao, Yao; Altundal, Yucel; Moreau, Michele; Sajo, Erno; Kumar, Rajiv; Ngwa, Wilfred

2015-09-01

Nanoparticle-aided radiation therapy is emerging as a promising modality to enhance radiotherapy via the radiosensitizing action of high atomic number (Z) nanoparticles. However, the delivery of sufficiently potent concentrations of such nanoparticles to the tumor remain a challenge. This study investigates the dose enhancement to lung tumors due to high-Z nanoparticles (NPs) administered via inhalation during external beam radiotherapy. Here NPs investigated include: cisplatin nanoparticles (CNPs), carboplatin nanoparticles (CBNPs), and gold nanoparticles (GNPs). Using Monte Carlo-generated megavoltage energy spectra, a previously employed analytic method was used to estimate dose enhancement to lung tumors due to radiation-induced photoelectrons from the NPs administered via inhalation route (IR) in comparison to intravenous (IV) administration. Previous studies have indicated about 5% of FDA-approved cisplatin concentrations reach the lung via IV. Meanwhile recent experimental studies indicate that 3.5-14.6 times higher concentrations of NPs can reach the lung by IR compared to IV. Taking these into account, the dose enhancement factor (DEF) defined as the ratio of the radiotherapy dose with and without nanoparticles was calculated for a range of NPs concentrations and tumor sizes. The DEF for IR was then compared with that for IV. For IR with 3.5 times higher concentrations than IV, and 2 cm diameter tumor, clinically significant DEF values of up to 1.19, 1.26, and 1.51 were obtained for CNPs, CBNPs and GNPs. In comparison values of 1.06, 1.08, and 1.15 were obtained via IV administration. For IR with 14.6 times higher concentrations, even higher DEF values were obtained e.g. 1.81 for CNPs. Results also showed that the DEF increased with increasing field size or decreasing tumor volume, as expected. The results of this work indicate that IR administration of targeted high-Z CNPs/CBNPs/GNPs could enable clinically significant DEF to lung tumors compared to IV

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

High biologically effective dose radiation therapy using brachytherapy in combination with external beam radiotherapy for high-risk prostate cancer

Directory of Open Access Journals (Sweden)

Keisei Okamoto

2017-02-01

Full Text Available Purpose : To evaluate the outcomes of high-risk prostate cancer patients treated with biologically effective dose (BED ≥ 220 Gy of high-dose radiotherapy, using low-dose-rate (LDR brachytherapy in combination with external beam radiotherapy (EBRT and short-term androgen deprivation therapy (ADT. Material and methods : From 2005 to 2013, a total of 143 patients with high-risk prostate cancer were treated by radiotherapy of BED ≥ 220 Gy with a combination of LDR brachytherapy, EBRT, and androgen deprivation therapy (ADT. The high-risk patients in the present study included both high-risk and very high-risk prostate cancer. The number of high-risk features were: 60 patients with 1 high-risk factor (42%, 61 patients with 2 high-risk factors (43%, and 22 patients with 3 high-risk factors (15% including five N1 disease. External beam radiotherapy fields included prostate and seminal vesicles only or whole pelvis depending on the extension of the disease. Biochemical failure was defined by the Phoenix definition. Results : Six patients developed biochemical failure, thus providing a 5-year actual biochemical failure-free survival (BFFS rate of 95.2%. Biochemical failure was observed exclusively in cases with distant metastasis in the present study. All six patients with biochemical relapse had clinical failure due to bone metastasis, thus yielding a 5-year freedom from clinical failure (FFCF rate of 93.0%. None of the cases with N1 disease experienced biochemical failure. We observed four deaths, including one death from prostate cancer, therefore yielding a cause-specific survival (CSS rate of 97.2%, and an overall survival (OS rate of 95.5%. Conclusions : High-dose (BED ≥ 220 Gy radiotherapy by LDR in combination with EBRT has shown an excellent outcome on BFFS in high-risk and very high-risk cancer, although causal relationship between BED and BFFS remain to be explained further.

Can the prostate brachytherapy by permanent implants represent an alternative to external radiotherapy for the localised prostate cancers with intermediary risk?

International Nuclear Information System (INIS)

Farnault, B.; Duberge, T.; Salem, N.; Boher, J.M.; Gravis, G.; Bladou, F.; Jochen, W.; Resbeut, M.

2009-01-01

Purpose: the prostate brachytherapy stands out as treatment of low risk prostate cancers, but the data concerning its use as exclusive treatment of intermediary risk prostate cancer are rare. We present a retrospective analysis of intermediary risk prostate cancers which treatment was either an external conformal radiotherapy or an exclusive brachytherapy. conclusion: In this mono centric series, the brachytherapy brings excellent results in comparison with external conformal radiotherapy with dose escalation and could be proposed as alternative to patients suffering of intermediary risk prostate cancer. (N.C.)

Successful treatment of a 67-year-old woman with urethral adenocarcinoma with the use of external beam radiotherapy and image guided adaptive interstitial brachytherapy

DEFF Research Database (Denmark)

Mujkanovic, Jasmin; Tanderup, Kari; Agerbæk, Mads

2016-01-01

Primary urethral cancer (PUC) is a very rare disease. This case report illustrates a successful treatment approach of a 67-year-old woman with a urethral adenocarcinoma selected for an organ preserving treatment with external beam radiotherapy (EBRT) and interstitial brachytherapy (BT) boost, using...

Patient costs associated with external beam radiotherapy treatment for localized prostate cancer: the benefits of hypofractionated over conventionally fractionated radiotherapy.

Science.gov (United States)

Sethukavalan, Perakaa; Cheung, Patrick; Tang, Colin I; Quon, Harvey; Morton, Gerard; Nam, Robert; Loblaw, Andrew

2012-04-01

To estimate the out-of-pocket costs for patients undergoing external beam radiotherapy (EBRT) for prostate cancer and calculate the patient-related savings of being treated with a 5-fraction versus a standard 39-fraction approach. Seventy patients accrued to the pHART3 (n = 84) study were analyzed for out-of-pocket patient costs as a result of undergoing treatment. All costs are in Canadian dollars. Using the postal code of the patient's residence, the distance between the hospital and patient home was found using Google Maps. The Canada Revenue Agency automobile allowance rate was then applied to determine the cost per kilometer driven. The average cost of travel from the hospital and pHART3 patient's residence was $246 per person after five trips. In a standard fractionation regimen, pHART3 patients would have incurred an average cost of $1921 after 39 visits. The patients receiving hypofractionated radiotherapy would have paid an average of $38 in parking while those receiving conventional treatment would have paid $293. The difference in out-of-pocket costs for the patients receiving a standard versus hypofractionated treatment was $1930. Medium term prospective data shows that hypofractionated radiotherapy is an effective treatment method for localized prostate cancer. Compared to standard EBRT, hypofractionated radiotherapy requires significantly fewer visits. Due to the long distance patients may have to travel to the cancer center and the expense of parking, the short course treatment saves each patient an average of $1900. A randomized study of standard versus hypofractionated accelerated radiotherapy should be conducted to confirm a favorable efficacy and tolerability profile of the shorter fractionation scheme.

Treatment of locally advanced breast carcinoma with high-dose external beam supervoltage radiotherapy

International Nuclear Information System (INIS)

Brufman, G.; Weshler, Z.; Prosnitz, L.R.; Fuks, Z.

1981-01-01

Between 1960 and 1978, 87 patients with locally advanced Tsub(3-4)Nsub(0-3)M 0 carcinoma of the breast were treated with 5,000 to 8,000 rad of external beam supervoltage radiotherapy. Initial clinical eradication of the tumour was observed in 76 of 87 cases (87%), but the actuarial probability of local control at 5 yr was only 53%. Furthermore, the actuarial probability of disease-free survival was 25% at 5 yr and 13% at 10 yr. Most of the patients eventually succumbed to metastatic breast carcinoma and the actuarial survival at 5 yr was 43% and at 10 yr, 16%. The addition of adjuvant low-dose chemotherapy, given to 13 patients, did not affect the rates of local control, survival or disease-free survival. The most common long-term complication was extensive and deforming radiation-induced fibrosis of the treated breast. The actuarial probability of 10-yr survival without a local recurrence and without severe fibrosis of the treated breast was only 17.5%. The role of adjuvant high-dose chemotherapy in the treatment of locally advanced breast carcinoma and the possible use of improved radiotherapy techniques to achieve a more effective long-term local control and a more desirable cosmetic end result are discussed. (author)

SU-E-T-66: A Prototype for Couch Based Real-Time Dosimetry in External Beam Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Ramachandran, P [Peter MacCallum Cancer Centre, Bendigo (Australia)

2015-06-15

Purpose: The main purpose of this study is to design a prototype for couch-based based real time dosimetry system in external beam radiotherapy Methods: A prototype of 100 ionization chambers was designed on a printed circuit board by etching the copper layer and each ionization chamber was wired to a 50 pin connector. The signals from the two 50 pin connectors collected from the ionization chambers were then transferred to a PXI module from National Instruments. The PXI module houses a current amplifier that amplifies the charge collected from the ionization chamber. The amplified signal is then sent to a digital multimeter module for converting the analog signal to digital signal. A software was designed in labview to read and display the signals obtained from the PXI module. A couch attachment frame was designed to house the 100 ionization chamber module. The frame was fixed underneath the treatment couch for measuring the dose during treatment. Resutls: The ionization chamber based prototype dosimetry was tested for simple radiotherapy treatment fields and found to be a useful device for measuring real time dosimetry at the treatment couch plane. This information could be used to assess the delivered dose to a patient during radiotherapy. It could be used as an invivo dosimeter during radiotherapy. Conclusion: In this study, a prototype for couch based real time dosimetry system was designed and tested. The prototype forms a basis for the development of large scale couch based real time dosimetry system that could be used to perform morning QA prior to treatment, assess real time doses delivered to patient and as a device to monitor the output of the treatment beam. Peter MacCallum Cancer Foundation.

SU-E-T-66: A Prototype for Couch Based Real-Time Dosimetry in External Beam Radiotherapy

International Nuclear Information System (INIS)

Ramachandran, P

2015-01-01

Purpose: The main purpose of this study is to design a prototype for couch-based based real time dosimetry system in external beam radiotherapy Methods: A prototype of 100 ionization chambers was designed on a printed circuit board by etching the copper layer and each ionization chamber was wired to a 50 pin connector. The signals from the two 50 pin connectors collected from the ionization chambers were then transferred to a PXI module from National Instruments. The PXI module houses a current amplifier that amplifies the charge collected from the ionization chamber. The amplified signal is then sent to a digital multimeter module for converting the analog signal to digital signal. A software was designed in labview to read and display the signals obtained from the PXI module. A couch attachment frame was designed to house the 100 ionization chamber module. The frame was fixed underneath the treatment couch for measuring the dose during treatment. Resutls: The ionization chamber based prototype dosimetry was tested for simple radiotherapy treatment fields and found to be a useful device for measuring real time dosimetry at the treatment couch plane. This information could be used to assess the delivered dose to a patient during radiotherapy. It could be used as an invivo dosimeter during radiotherapy. Conclusion: In this study, a prototype for couch based real time dosimetry system was designed and tested. The prototype forms a basis for the development of large scale couch based real time dosimetry system that could be used to perform morning QA prior to treatment, assess real time doses delivered to patient and as a device to monitor the output of the treatment beam. Peter MacCallum Cancer Foundation

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)

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

International Nuclear Information System (INIS)

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

2006-01-01

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

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)

Evaluation of a mixed beam therapy for post-mastectomy breast cancer patients: bolus electron conformal therapy combined with intensity modulated photon radiotherapy and volumetric modulated photon arc therapy.

Science.gov (United States)

Zhang, Rui; Heins, David; Sanders, Mary; Guo, Beibei; Hogstrom, Kenneth

2018-05-10

The purpose of this study was to assess the potential benefits and limitations of a mixed beam therapy, which combined bolus electron conformal therapy (BECT) with intensity modulated photon radiotherapy (IMRT) and volumetric modulated photon arc therapy (VMAT), for left-sided post-mastectomy breast cancer patients. Mixed beam treatment plans were produced for nine post-mastectomy radiotherapy (PMRT) patients previously treated at our clinic with VMAT alone. The mixed beam plans consisted of 40 Gy to the chest wall area using BECT, 40 Gy to the supraclavicular area using parallel opposed IMRT, and 10 Gy to the total planning target volume (PTV) by optimizing VMAT on top of the BECT+IMRT dose distribution. The treatment plans were created in a commercial treatment planning system (TPS), and all plans were evaluated based on PTV coverage, dose homogeneity index (DHI), conformity index (CI), dose to organs at risk (OARs), normal tissue complication probability (NTCP), and secondary cancer complication probability (SCCP). The standard VMAT alone planning technique was used as the reference for comparison. Both techniques produced clinically acceptable PMRT plans but with a few significant differences: VMAT showed significantly better CI (0.70 vs. 0.53, p 0.5 cm and volume of tissue between the distal PTV surface and heart or lung approximately > 250 cm 3 ) between distal PTV surface and lung may benefit the most from mixed beam therapy. This work has demonstrated that mixed beam therapy (BECT+IMRT : VMAT = 4 : 1) produces clinically acceptable plans having reduced OAR doses and risks of side effects compared with VMAT. Even though VMAT alone produces more homogenous and conformal dose distributions, mixed beam therapy remains as a viable option for treating post-mastectomy patients, possibly leading to reduced normal tissue complications. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Unilateral solitary choroid metastasis from breast cancer: Rewarding results of external radiotherapy

Directory of Open Access Journals (Sweden)

Nirmala S

2008-01-01

Full Text Available Intraocular metastatic tumor is the commonest intraocular malignancy in adults, with uveal tract the commonest site. In nearly 85% of cases the choroid is the afflicted site due to its vascularity. Breast and lung are the common primaries. In breast primaries, this could be the first metastatic disease. This condition should always be kept in mind in patients with visual symptoms. Fundus examination, ultrasonography and CT/MRI of the orbit help in diagnosis. Early recognition and timely treatment can save the visual function thus imparting good quality of life to the patient. External beam radiotherapy is a good local form of treatment. Hormone therapy in hormone receptor positive tumors can have additional benefits. Here we report a case of unilateral solitary choroid metastasis in a case of breast cancer treated with external beam radiotherapy.

Intermediate-term results of image-guided brachytherapy and high-technology external beam radiotherapy in cervical cancer: Chiang Mai University experience.

Science.gov (United States)

Tharavichitkul, Ekkasit; Chakrabandhu, Somvilai; Wanwilairat, Somsak; Tippanya, Damrongsak; Nobnop, Wannapha; Pukanhaphan, Nantaka; Galalae, Razvan M; Chitapanarux, Imjai

2013-07-01

To evaluate the outcomes of image-guided brachytherapy combined with 3D conformal or intensity modulated external beam radiotherapy (3D CRT/IMRT) in cervical cancer at Chiang Mai University. From 2008 to 2011, forty-seven patients with locally advanced cervical cancer were enrolled in this study. All patients received high-technology (3D CRT/IMRT) whole pelvic radiotherapy with a total dose of 45-46 Gy plus image-guided High-Dose-Rate intracavitary brachytherapy 6.5-7 Gy × 4 fractions to a High-Risk Clinical Target Volume (HR-CTV) according to GEC-ESTRO recommendations. The dose parameters of the HR-CTV for bladder, rectum and sigmoid colon were recorded, as well as toxicity profiles. In addition, the endpoints for local control, disease-free, metastasis-free survival and overall survival were calculated. At the median follow-up time of 26 months, the local control, disease-free survival, and overall survival rates were 97.9%, 85.1%, and 93.6%, respectively. The mean dose of HR-CTV, bladder, rectum and sigmoid were 93.1, 88.2, 69.6, and 72 Gy, respectively. In terms of late toxicity, the incidence of grade 3-4 bladder and rectum morbidity was 2.1% and 2.1%, respectively. A combination of image-guided brachytherapy and IMRT/3D CRT showed very promising results of local control, disease-free survival, metastasis-free survival and overall survival rates. It also caused a low incidence of grade 3-4 toxicity in treated study patients. Copyright © 2013 Elsevier Inc. All rights reserved.

Can All Centers Plan Intensity-Modulated Radiotherapy (IMRT) Effectively? An External Audit of Dosimetric Comparisons Between Three-Dimensional Conformal Radiotherapy and IMRT for Adjuvant Chemoradiation for Gastric Cancer

International Nuclear Information System (INIS)

Chung, Hans T.; Lee, Brian; Park, Eileen; Lu, Jiade J.; Xia Ping

2008-01-01

Purpose: To compare dosimetric endpoints between three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) at our center with limited IMRT experience, and to perform an external audit of the IMRT plans. Methods and Materials: Ten patients, who received adjuvant chemoradiation for gastric cancer, formed the study cohort. For standardization, the planning target volume (PTV) and organs at risk were recontoured with the assistance of a study protocol radiologic atlas. The cohort was replanned with CMS Xio to generate coplanar 3D-CRT and IMRT plans. All 10 datasets, including volumes but without the plans (i.e., blinded), were transmitted to an experienced center where IMRT plans were designed using Nomos Corvus (IMRT-C) and ADAC Pinnacle (IMRT-P). All IMRT plans were normalized to D95% receiving 45 Gy. Results: Intensity-modulated radiotherapy yielded higher PTV V45 (volume that receives ≥45 Gy) (p < 0.001) than 3D-CRT. No difference in V20 was seen in the right (p = 0.9) and left (p 0.3) kidneys, but the liver mean dose (p < 0.001) was superior with IMRT. For the external audit, IMRT-C (p = 0.002) and IMRT-P (p < 0.001) achieved significantly lower left kidney V20 than IMRT, and IMRT-P (p < 0.001) achieved lower right kidney V20 than IMRT. The IMRT-C (p = 0.003) but not IMRT-P (p = 0.6) had lower liver mean doses than IMRT. Conclusions: At our institution with early IMRT experience, IMRT improved PTV dose coverage and liver doses but not kidney doses. An external audit of IMRT plans showed that an experienced center can yield superior IMRT plans

Normal tissue tolerance to external beam radiation therapy: Thyroid; Dose de tolerance des tissus sains: la thyroide

Energy Technology Data Exchange (ETDEWEB)

Berges, O.; Giraud, P. [Service d' oncologie-radiotherapie, hopital europeen Georges-Pompidou, universite Paris Descartes, 75 - Paris (France); Belkacemi, Y. [Service d' oncologie-radiotherapie, CHU Henri-Mondor, universite Paris 12, 94 - Creteil (France)

2010-07-15

The thyroid is the most developed endocrine gland of the body. Due to its anatomical location, it may be exposed to ionizing radiation in external radiotherapy involving head and neck. This review aims to describe the thyroid radiation disorders, probably under-reported in the literature, their risk factors and follow-up procedures. The functional changes after external beam radiation consists mainly of late effects occurring beyond 6 months, and are represented by the clinical and subclinical hypothyroidism. Its incidence is approximately 20 to 30% and it can occur after more than 25 years after radiation exposure. Hyperthyroidism and auto-immune manifestations have been described in a lesser proportion. The morphological changes consist of benign lesions, primarily adenomas, and malignant lesions, the most feared and which incidence is 0.35%. The onset of hypothyroidism depends of the total dose delivered to the gland, and the irradiated. Modern techniques of conformal radiotherapy with modulated intensity could improve the preservation of the thyroid, at the expense of the increase in low doses and the theoretical risk of secondary cancers. (authors)

Conformal radiotherapy for prostate cancer: contribution of pelvic immobilization and new fiducial markers

International Nuclear Information System (INIS)

Garcia, R.; Oozeer, R.; Le Thanh, H.; Chauvet, B.; Toy, B.J.; Reboul, F.

1997-01-01

To reduce errors in the positioning of patients treated with external conformal radiotherapy for prostate cancer, we evaluated both the use of an immobilization device and new fiducial markers. The immobilization device consisted of an individual mold made of polyurethane foam. Two sets of skin markers located on the anterior tibial surfaces were used to identify the pelvic isocenter. The patient's position was evaluated by orthogonal port film which were then compared with the original simulation film. Results are presented with respect to orthogonal axes. Comparison with classic procedures without immobilization showed that use of the mold and new fiducial markers led to a decrease in set-up errors which were less than 5 mm. With the use of an immobilization device and optimized techniques for patients' positioning, conformal radiotherapy of prostate cancer is more accurate. (authors)

Gel dosimetry for conformal radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Gambarini, G [Department of Physics of the University and INFN, Milan (Italy)

2005-07-01

With the continuum development of conformal radio therapies, aimed at delivering high dose to tumor tissue and low dose to the healthy tissue around, the necessities has appeared of suitable improvement of dosimetry techniques giving the possibility of obtaining dose images to be compared with diagnostic images. Also if wide software has been developed for calculating dose distributions in the fields of various radiotherapy units, experimental verifications are necessary, in particular in the case of complex geometries in conformal radiotherapy. Gel dosimetry is a promising method for imaging the absorbed dose in tissue-equivalent phantoms, with the possibility of 3D reconstruction of the spatial dose distribution, with milli metric resolution. Optical imaging of gel dosimeters, based on visible light absorbance analysis, has shown to be a reliable technique for achieving dose distributions. (Author)

Metallic stent and stereotactic conformal radiotherapy for hilar cholangiocarcinoma

International Nuclear Information System (INIS)

Li Yu; Wang Ning; Tian Qihe; Guo Zhanwen; Zhang Haibo; Song Liyan

2005-01-01

Objective: To evaluate the effect of metallic stent combined with stereotactic conformal radiotherapy (SCRT) for hilar cholangiocarcinoma. Methods: Fifty-four patients with hilar cholangiocarcinoma were analyzed, including 31 treated with stent plus stereotactic conformal radiotherapy (combined group) and 23 with metallic stent alone (control group). Results: The mean survival time of combined group was 11.1 ± 4.6 months, compared with 5.1 ± 2.8 months of the control group, giving a significant difference between the two groups (P<0.01). Conclusion: The combination of metallic stent and stereotactic conformal radiotherapy is more effective than metallic stent alone for unresectable hilar cholangiocarcinoma. (authors)

External respiratory motion for abdominal radiotherapy patients: implications for patient alignment

International Nuclear Information System (INIS)

Kearvell, Rachel; Ebert, Martin A.

2003-01-01

Conformal external beam radiotherapy relies on accurate spatial positioning of the tumor and normal tissues during treatment. For abdominal patients, this is complicated by the motion of internal organs and the external patient contour due to respiration. As external motion influences the degree of accuracy achievable in patient setup, this motion was studied to provide indication of motions occurring during treatment, as well as to assess the technique of breath-holding at exhale (B-HEX). The motion of external abdominal points (anterior and right lateral) of a series of volunteers was tracked in real-time using an infrared tracking system, with the volunteers in treatment position. The resulting motion data was assessed to evaluate (1) the change in position of each point per breath/breath-hold, (2) the change in position between breaths/breath-holds, and (3) the change in position across the whole recording time. Analysis shows that, for the anterior abdominal point, there is little difference in the variation of position with time for free-breathing as opposed to the B-HEX technique. For the lateral point however, the B-HEX technique reduces the motion during each treatment cycle (i.e., during the breath-hold) and over an extended period (i.e., during a series of breath-holds). The B-HEX technique thus provides greater accuracy for setup to lateral markers and provides the opportunity to reduce systematic and random localization errors

TECHNOLOGIES FOR DELIVERY OF PROTON AND ION BEAMS FOR RADIOTHERAPY

CERN Document Server

Owen, H; Alonso, J; Mackay, R

2014-01-01

Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

Combination of peptide receptor radionuclide therapy with fractionated external beam radiotherapy for treatment of advanced symptomatic meningioma

International Nuclear Information System (INIS)

Kreissl, Michael C; Flentje, Michael; Sweeney, Reinhart A; Hänscheid, Heribert; Löhr, Mario; Verburg, Frederik A; Schiller, Markus; Lassmann, Michael; Reiners, Christoph; Samnick, Samuel S; Buck, Andreas K

2012-01-01

External beam radiotherapy (EBRT) is the treatment of choice for irresectable meningioma. Due to the strong expression of somatostatin receptors, peptide receptor radionuclide therapy (PRRT) has been used in advanced cases. We assessed the feasibility and tolerability of a combination of both treatment modalities in advanced symptomatic meningioma. 10 patients with irresectable meningioma were treated with PRRT ( 177 Lu-DOTA0,Tyr3 octreotate or - DOTA0,Tyr3 octreotide) followed by external beam radiotherapy (EBRT). EBRT performed after PRRT was continued over 5–6 weeks in IMRT technique (median dose: 53.0 Gy). All patients were assessed morphologically and by positron emission tomography (PET) before therapy and were restaged after 3–6 months. Side effects were evaluated according to CTCAE 4.0. Median tumor dose achieved by PRRT was 7.2 Gy. During PRRT and EBRT, no side effects > CTCAE grade 2 were noted. All patients reported stabilization or improvement of tumor-associated symptoms, no morphologic tumor progression was observed in MR-imaging (median follow-up: 13.4 months). The median pre-therapeutic SUV max in the meningiomas was 14.2 (range: 4.3–68.7). All patients with a second PET after combined PRRT + EBRT showed an increase in SUV max (median: 37%; range: 15%–46%) to a median value of 23.7 (range: 8.0–119.0; 7 patients) while PET-estimated volume generally decreased to 81 ± 21% of the initial volume. The combination of PRRT and EBRT is feasible and well tolerated. This approach represents an attractive strategy for the treatment of recurring or progressive symptomatic meningioma, which should be further evaluated

Six fractions per week of external beam radiotherapy and high-dose-rate brachytherapy for carcinoma of the uterine cervix: A phase I/II study

International Nuclear Information System (INIS)

Yoon, Sang Min; Huh, Seung Jae; Park, Won; Lee, Jeung Eun; Park, Young Je; Nam, Hee Rim; Lim, Do Hoon; Ahn, Yong Chan

2006-01-01

Purpose: This study evaluated the treatment results of external beam radiotherapy administered in six fractions per week and high-dose-rate (HDR) brachytherapy for the treatment of cervical cancer. Methods and Materials: From July 2000 to July 2003, 43 patients were enrolled in this study. The patients received 45 Gy from a 10-MV photon beam using four-field box or anterior-posterior beams. Parametrial regions and the pelvic side walls were boosted with up to 50.4 Gy using a midline block. The daily fraction dose was 1.8 Gy administered in six-weekly fractions, from Monday to Saturday. HDR brachytherapy was also delivered at doses of 24 Gy to point A in six fractions twice a week. The median follow-up time was 37 months (range, 9-60 months). Results: The median overall treatment time was 51 days for all patients (range, 44-62 days). Thirty-four patients (79.1%) achieved complete remission and 8 (18.6%) achieved partial remission after radiotherapy. Locoregional recurrence occurred in 5 patients (11.6%), and a distant metastasis was encountered in 6 patients (13.9%). The 3-year overall survival, locoregional, and distant metastasis-free survival rates were 74.7%, 87.8%, and 84.7%, respectively. Grade 2 and 3 late rectal complications were encountered in 3 (6.5%) and 1 (2.2%), respectively. There were no Grade 3 late bladder complications. Conclusions: Six fractions per week of external beam radiotherapy and HDR brachytherapy is an effective treatment for patients with a carcinoma of the uterine cervix and can be used as a possible alternative to concomitant chemoradiotherapy in elderly patients or in patients with co-morbidity

A criterion-based audit of the technical quality of external beam radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Brundage, Michael; Danielson, Brita; Pearcey, Robert; Bass, Brenda; Pickles, Tom; Bahary, Jean-Paul; Peng, Yingwei; Wallace, David; Mackillop, William

2013-01-01

Purpose: To evaluate the technical quality of external beam radiotherapy for prostate cancer in Canada. Methods: This was a multi-institution, retrospective study of a random sample of patients undergoing radiotherapy (RT) for prostate cancer in Canada. Patterns of care were determined by abstracting details of the patients’ management from original records. The quality of patient’s technical care was measured against a previously published, comprehensive suite of quality indicators. Results: 32 of the 37 RT centres participated. The total study population of 810 patients included 25% low-risk, 44% intermediate-risk, and 28% high-risk cases. 649 received external beam RT (EBRT) only, for whom compliance with 12 indicators of the quality of pre-treatment assessment ranged from 56% (sexual function documented) to 96% (staging bone scan obtained in high-risk patients). Compliance with treatment-related indicators ranged from 78% (dose to prostate ⩾74 Gy in intermediate risk patients not receiving hormone therapy) to 100% (3DCRT or IMRT plan). Compliance varied among centres; no centre demonstrated 100% compliance on all indicators and every centre was 100% compliant on at least some indicators. The number of assessment-related indicators (n = 13) with which a given centre was 100% compliant ranged from 4 to 11 (median 7) and the number of the treatment-specific indicators (n = 8) with which a given centre was 100% compliant ranged from 6 to 8 (median 8). ADT therapy was utilised in most high-risk cases (191, 92.3%). Conclusions: While patterns of prostate cancer care in Canada vary somewhat, compliance on the majority of quality indicators is very high. However, all centres showed room for improvement on several indicators and few individual patients received care that met target benchmarks on all quality measures. This variation is particularly important for indicators such as delivered dose where impact on disease outcome is known to exist, and suggests that

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...

Palliative external-beam radiotherapy for bone metastases from hepatocellular carcinoma

Institute of Scientific and Technical Information of China (English)

Shinya; Hayashi; Hidekazu; Tanaka; Hiroaki; Hoshi

2014-01-01

The incidence of bone metastases(BMs)from hepatocellular carcinoma(HCC)is relatively low compared to those of other cancers,but it has increased recently,especially in Asian countries.Typically,BMs from HCC appear radiologically as osteolytic,destructive,and expansive components with large,bulky soft-tissue masses.These soft-tissue masses are unique to bone metastases from HCC and often replace the normal bone matrix and exhibit expansive growth.They often compress the peripheral nerves,spinal cord,or cranial nerves,causing not only bone pain but also neuropathic pain and neurological symptoms.In patients with spinal BMs,the consequent metastatic spinal cord compression(MSCC)causes paralysis.Skull base metastases(SBMs)with cranial nerve involvement can cause neurological symptoms.Therefore,patients with bony lesions often suffer from pain or neurological symptoms that have a severe,adverse effect on the quality of life.External-beam radiotherapy(EBRT)can effectively relieve bone pain and neurological symptoms caused by BMs.However,EBRT is not yet widely used for the palliative management of BMs from HCC because of the limited number of relevant studies.Furthermore,the optimal dosing schedule remains unclear,despite clinical evidence to support single-fraction ra-diation schedules for primary cancers.In this review,we outline data describing palliative EBRT for BMs from HCC in the context of(1)bone pain;(2)MSCC;and(3)SBMs.

Prospective randomized trail on chrono-chemotherapy + late course three dimensional conformal radio-therapy and conventional chemotherapy plus radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Jin Feng; Ouyang Jinling; Dong Hongmin; Wu Weili; Chen Haixia; He Zhihui

2005-01-01

Objective: To compare the therapeutic effects, toxic side effects of late-course three dimensional conformal radiotherapy plus chrono-chemotherapy (DDP + 5-FU/CF) and conventional radiotherapy plus chemotherapy for nasopharyngeal carcinoma (NPC). Methods: Eighty -six NPC patients admitted from Feb. 2001 to Jan. 2002 were divided randomly into two groups: 1. Chrono-chemotherapy + late course three dimensional conformal radiotherapy(CCR) group-44 patients were treated by late course three dimensional conformal radio-therapy plus chrono-chemotherapy, and 2. Routine-chemotherapy-radiotherapy (RCR) group-42 patients were treated by routine chemotherapy plus radiotherapy. The patients in CCR and RCR group were comparable in age, KPS, stage and pathology. All patients were treated by combined chemotherapy and radiotherapy, with chemotherapy stared 2 weeks ahead of radiotherapy. Chemotherapy: Braun pump was used in all drug infusions; 1. CCR group-DDP 80 mg/ m 2 starting from 10:00 until 22:00, 5-Fu 750 mg/d/m 2 starting from 22:00 until 10:00 next day, CF 200 mg/d/m 2 starting from 10:00 every day, infused at normal speed. These drugs were given for 3 days, 14 days as one cycle, totally 2 cycle, and 2. RCR group-with the same drugs at the same total dose, only with the difference being DDP and CF given QD, starting from 10:00 but at the normal speed. 5-Fu was given through-out the day and continuously for 3 days, totally for 2 cycles. Radiotherapy: linear accelerator irradiation was given to either group. Composite facio-cervical field + anterior cervical tangential field to D T 40 Gy/4w, followed by the coned down per-auricular field plus anterior tangential field or β beam irradiation. In CCR group, after D T 40gy/4w, late course 3-dimensional conformal radiotherapy (3DCRT) was used to add D T 30Gy/3w. In RCR group, routine radiotherapy of 40 Gy/w was supplemented with 30 Gy/3w. The total dose in either group was 70 Gy/7w at the nasopharynx, D T 60-70 Gy/6-7w at the

Comparative sensitivities of functional MRI sequences in detection of local recurrence of prostate carcinoma after radical prostatectomy or external-beam radiotherapy.

Science.gov (United States)

Roy, Catherine; Foudi, Fatah; Charton, Jeanne; Jung, Michel; Lang, Hervé; Saussine, Christian; Jacqmin, Didier

2013-04-01

The aim of this retrospective study was to determine the respective accuracies of three types of functional MRI sequences-diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) MRI, and 3D (1)H-MR spectroscopy (MRS)-in the depiction of local prostate cancer recurrence after two different initial therapy options. From a cohort of 83 patients with suspicion of local recurrence based on prostate-specific antigen (PSA) kinetics who were imaged on a 3-T MRI unit using an identical protocol including the three functional sequences with an endorectal coil, we selected 60 patients (group A, 28 patients who underwent radical prostatectomy; group B, 32 patients who underwent external-beam radiation) who had local recurrence ascertained on the basis of a transrectal ultrasound-guided biopsy results and a reduction in PSA level after salvage therapy. All patients presented with a local relapse. Sensitivity with T2-weighted MRI and 3D (1)H-MRS sequences was 57% and 53%, respectively, for group A and 71% and 78%, respectively, for group B. DCE-MRI alone showed a sensitivity of 100% and 96%, respectively, for groups A and B. DWI alone had a higher sensitivity for group B (96%) than for group A (71%). The combination of T2-weighted imaging plus DWI plus DCE-MRI provided a sensitivity as high as 100% in group B. The performance of functional imaging sequences for detecting recurrence is different after radical prostatectomy and external-beam radiotherapy. DCE-MRI is a valid and efficient tool to detect prostate cancer recurrence in radical prostatectomy as well as in external-beam radiotherapy. The combination of DCE-MRI and DWI is highly efficient after radiation therapy. Three-dimensional (1)H-MRS needs to be improved. Even though it is not accurate enough, T2-weighted imaging remains essential for the morphologic analysis of the area.

External Beam Radiotherapy for Colon Cancer: Patterns of Care

International Nuclear Information System (INIS)

Dunn, Emily F.; Kozak, Kevin R.; Moody, John S.

2010-01-01

Purpose: Despite its common and well characterized use in other gastrointestinal malignancies, little is known about radiotherapy (RT) use in nonmetastatic colon cancer in the United States. To address the paucity of data regarding RT use in colon cancer management, we examined the RT patterns of care in this patient population. Methods and Materials: Patients with nonmetastatic colon cancer, diagnosed between 1988 and 2005, were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate methods were used to identify factors associated with RT use. Results: On univariate analysis, tumor location, age, sex, race, T stage, N stage, and geographic location were each associated with differences in RT use (all p < 0.01). In general, younger patients, male patients, and patients with more advanced disease were more likely to receive RT. On multivariate analysis, tumor location, age, gender, T and N stage, time of diagnosis and geographic location were significantly associated with RT use (all p < 0.001). Race, however, was not associated with RT use. On multivariate analysis, patients diagnosed in 1988 were 2.5 times more likely to receive RT than those diagnosed in 2005 (p = 0.001). Temporal changes in RT use reflect a responsiveness to evolving evidence related to the therapeutic benefits of adjuvant RT. Conclusions: External beam RT is infrequently used for colon cancer, and its use varies according to patient and tumor characteristics. RT use has declined markedly since the late 1980s; however, it continues to be used for nonmetastatic disease in a highly individualized manner.

Radical External Beam Radiotherapy for Clinically Localized Prostate Cancer in Japan: Changing Trends in the Patterns of Care Process Survey

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Kazuhiko, E-mail: kogawa@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, Okinawa (Japan); Nakamura, Katsumasa [Department of Clinical Radiology, Kyushu University Hospital at Beppu, Oita (Japan); Sasaki, Tomonari [Department of Radiation Oncology, National Kyushu Center, Fukuoka (Japan); Onishi, Hiroshi [Department of Radiology, Yamanashi University, Yamanashi (Japan); Koizumi, Masahiko [Department of Radiation Oncology, Osaka University, Osaka (Japan); Araya, Masayuki [Department of Radiology, Yamanashi University, Yamanashi (Japan); Mukumoto, Nobutaka; Teshima, Teruki [Department of Medical Physics and Engineering, Osaka University, Osaka (Japan); Mitsumori, Michihide [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University, Kyoto (Japan)

2011-12-01

Purpose: To delineate changing trends in radical external beam radiotherapy (EBRT) for prostate cancer in Japan. Methods and Materials: Data from 841 patients with clinically localized prostate cancer treated with EBRT in the Japanese Patterns of Care Study (PCS) from 1996 to 2005 were analyzed. Results: Significant increases in the proportions of patients with stage T1 to T2 disease and decrease in prostate-specific antigen values were observed. Also, there were significant increases in the percentages of patients treated with radiotherapy by their own choice. Median radiation doses were 65.0 Gy and 68.4 Gy from 1996 to 1998 and from 1999 to 2001, respectively, increasing to 70 Gy from 2003 to 2005. Moreover, conformal therapy was more frequently used from 2003 to 2005 (84.9%) than from 1996 to 1998 (49.1%) and from 1999 to 2001 (50.2%). On the other hand, the percentage of patients receiving hormone therapy from 2003 to 2005 (81.1%) was almost the same as that from 1996 to 1998 (86.3%) and from 1999 to 2001 (89.7%). Compared with the PCS in the United States, patient characteristics and patterns of treatments from 2003 to 2005 have become more similar to those in the United States than those from 1996 to 1998 and those from 1999 to 2001. Conclusions: This study indicates a trend toward increasing numbers of patients with early-stage disease and increasing proportions of patients treated with higher radiation doses with advanced equipment among Japanese prostate cancer patients treated with EBRT during 1996 to 2005 survey periods. Patterns of care for prostate cancer in Japan are becoming more similar to those in the United States.

Monitor tables for electron beams in radiotherapy

International Nuclear Information System (INIS)

Christ, G.; Dohm, O.S.

2007-01-01

The application of electron beams in radiotherapy is still based on tables of monitor units, although 3-D treatment planning systems for electron beams are available. This have several reasons: The need for 3-D treatment planning is not recognized; there is no confidence in the calculation algorithm; Monte-Carlo algorithms are too time-consuming; and the effort necessary to measure basic beam data for 3-D planning is considered disproportionate. However, the increasing clinical need for higher dosimetric precision and for more conformal electron beams leads to the requirement for more sophisticated tables of monitor units. The present paper summarizes and discusses the main aspects concerning the preparation of tables of monitor units for electron beams. The measurement equipment and procedures for measuring basic beam data needed for tables of monitor units for electron beams are described for a standard radiation therapy linac. The design of tables of monitor units for standard electron applicators is presented; this design can be extended for individual electron inserts, to variable applicator surface distances, to oblique beam incidence, and the use of bolus material. Typical data of an Elekta linac are presented in various tables. (orig.)

External validation of three dimensional conformal radiotherapy based NTCP models for patient-rated xerostomia and sticky saliva among patients treated with intensity modulated radiotherapy

International Nuclear Information System (INIS)

Beetz, Ivo; Schilstra, Cornelis; Luijk, Peter van; Christianen, Miranda E.M.C.; Doornaert, Patricia; Bijl, Henk P.; Chouvalova, Olga; Heuvel, Edwin R. van den; Steenbakkers, Roel J.H.M.; Langendijk, Johannes A.

2012-01-01

Purpose: The purpose of this study was to investigate the ability of predictive models for patient-rated xerostomia (XER 6M ) and sticky saliva (STIC 6M ) at 6 months after completion of primary (chemo)radiation developed in head and neck cancer patients treated with 3D-conformal radiotherapy (3D-CRT) to predict outcome in patients treated with intensity modulated radiotherapy (IMRT). Methods and materials: Recently, we published the results of a prospective study on predictive models for patient-rated xerostomia and sticky saliva in head and neck cancer patients treated with 3D-CRT (3D-CRT based NTCP models). The 3D-CRT based model for XER 6M consisted of three factors, including the mean parotid dose, age, and baseline xerostomia (none versus a bit). The 3D-CRT based model for STIC 6M consisted of the mean submandibular dose, age, the mean sublingual dose, and baseline sticky saliva (none versus a bit). In the current study, a population consisting of 162 patients treated with IMRT was used to test the external validity of these 3D-CRT based models. External validity was described by the explained variation (R 2 Nagelkerke) and the Brier score. The discriminative abilities of the models were calculated using the area under the receiver operating curve (AUC) and calibration (i.e. the agreement between predicted and observed outcome) was assessed with the Hosmer–Lemeshow “goodness-of-fit” test. Results: Overall model performance of the 3D-CRT based predictive models for XER 6M and STIC 6M was significantly worse in terms of the Brier score and R 2 Nagelkerke among patients treated with IMRT. Moreover the AUC for both 3D-CRT based models in the IMRT treated patients were markedly lower. The Hosmer–Lemeshow test showed a significant disagreement for both models between predicted risk and observed outcome. Conclusion: 3D-CRT based models for patient-rated xerostomia and sticky saliva among head and neck cancer patients treated with primary radiotherapy or

Measurement and properties of the dose-area product ratio in external small-beam radiotherapy.

Science.gov (United States)

Niemelä, Jarkko; Partanen, Mari; Ojala, Jarkko; Sipilä, Petri; Björkqvist, Mikko; Kapanen, Mika; Keyriläinen, Jani

2017-06-21

In small-beam radiation therapy (RT) the measurement of the beam quality parameter, i.e. the tissue-phantom ratio or TPR 20,10 , using a conventional point detector is a challenge. To obtain reliable results, one has to consider potential sources of error, including volume averaging and adjustment of the point detector into the narrow beam. To overcome these challenges, a different type of beam quality parameter in small beams was studied, namely the dose-area product ratio, or DAPR 20,10 . With this method, the measurement of a dose-area product (DAP) using a large-area plane-parallel chamber (LAC) eliminates the uncertainties in detector positioning and volume averaging that are present when using a point detector. In this study, the properties of the DAPR 20,10 of a cone-collimated 6 MV photon beam were investigated using Monte Carlo (MC) calculations and the obtained values were compared to measurements obtained using two LAC detectors, PTW Type 34073 and PTW Type 34070. In addition, the possibility of determining the DAP using EBT3 film and a Razor diode detector was studied. The determination of the DAPR 20,10 value was found to be feasible in external small-beam radiotherapy using cone-collimated beams with diameters from 4-40 mm, based on the results of the two LACs, the MC calculations and the Razor diode. The measurements indicated a constant DAPR 20,10 value for fields 20-40 mm in diameter, with a maximum relative change of 0.6%, but an increase of 7.0% for fields from 20-4 mm in diameter for the PTW Type 34070 chamber. Simulations and measurements showed an increase of DAPR 20,10 with increasing LAC size or dose integral area for the studied 4-40 mm cone-collimated 6 MV photon beams. This has the consequence that there should be a reference to the size of the used LAC active area or the DAP integration area with the reported DAPR 20,10 value.

Measurement and properties of the dose-area product ratio in external small-beam radiotherapy

Science.gov (United States)

Niemelä, Jarkko; Partanen, Mari; Ojala, Jarkko; Sipilä, Petri; Björkqvist, Mikko; Kapanen, Mika; Keyriläinen, Jani

2017-06-01

In small-beam radiation therapy (RT) the measurement of the beam quality parameter, i.e. the tissue-phantom ratio or TPR20,10, using a conventional point detector is a challenge. To obtain reliable results, one has to consider potential sources of error, including volume averaging and adjustment of the point detector into the narrow beam. To overcome these challenges, a different type of beam quality parameter in small beams was studied, namely the dose-area product ratio, or DAPR20,10. With this method, the measurement of a dose-area product (DAP) using a large-area plane-parallel chamber (LAC) eliminates the uncertainties in detector positioning and volume averaging that are present when using a point detector. In this study, the properties of the DAPR20,10 of a cone-collimated 6 MV photon beam were investigated using Monte Carlo (MC) calculations and the obtained values were compared to measurements obtained using two LAC detectors, PTW Type 34073 and PTW Type 34070. In addition, the possibility of determining the DAP using EBT3 film and a Razor diode detector was studied. The determination of the DAPR20,10 value was found to be feasible in external small-beam radiotherapy using cone-collimated beams with diameters from 4-40 mm, based on the results of the two LACs, the MC calculations and the Razor diode. The measurements indicated a constant DAPR20,10 value for fields 20-40 mm in diameter, with a maximum relative change of 0.6%, but an increase of 7.0% for fields from 20-4 mm in diameter for the PTW Type 34070 chamber. Simulations and measurements showed an increase of DAPR20,10 with increasing LAC size or dose integral area for the studied 4-40 mm cone-collimated 6 MV photon beams. This has the consequence that there should be a reference to the size of the used LAC active area or the DAP integration area with the reported DAPR20,10 value.

Gas in the rectum tends to reduce during radical external beam radiotherapy for localised prostate cancer

International Nuclear Information System (INIS)

Nakamura, Naoki; Mizuno, Norifumo; Endo, Haruna; Ogita, Mami; Kawamori, Jiro; Sekigucho, Kenji; Hatanaka, Shogo; Takahashi, Osamu; Tamaki, Seiichi; Shikama, Naoto

2014-01-01

This study aims to clarify the time-course of gas accumulation in the rectum during treatment as guidance for the management of rectal volumes. We reviewed 2042 sets (35.2 sets per patient) of anteroposterior and right–left mega voltage (MV) images obtained for daily set-up from 58 patients who underwent radical external beam radiotherapy for localised prostate cancer. The patients were instructed to take magnesium oxide tablets during radiotherapy. They were also encouraged to avoid foods that might cause intestinal gas during radiotherapy. Gas accumulation in the rectum was graded into three classes by the same radiation oncologist. If no gas was seen in the rectum, it was classified as grade 0. A small amount of gas was classified as grade 1, whereas a marked amount of gas that required removal was classified as grade 2. Of the 2042 sets of MV images, grades 1 and 2 gas accumulation were seen in 332 (16%) and 156 (8%), respectively. By the trend test, gas accumulation significantly decreased towards the end of treatment (P=0.02 for grade 1 or 2 and P=0.02 for grade 2). On multivariate analysis, we did not identify any significant independent predictors for either baseline gas accumulation or gas reduction. Gas accumulation tended to decrease until the end of treatment. This tendency should be reconfirmed by other institutions.

Intensity modulated radiotherapy (IMRT) in bilateral retinoblastoma

International Nuclear Information System (INIS)

Atalar, Banu; Ozyar, Enis; Gunduz, Kaan; Gungor, Gorkem

2010-01-01

External beam radiotherapy (EBRT) for retinoblastoma has traditionally been done with conventional radiotherapy techniques which resulted high doses to the surrounding normal tissues. A 20 month-old girl with group D bilateral retinoblastoma underwent intensity modulated radiotherapy (IMRT) to both eyes after failing chemoreduction and focal therapies including cryotherapy and transpupillary thermotherapy. In this report, we discuss the use of IMRT as a method for reducing doses to adjacent normal tissues while delivering therapeutic doses to the tumour tissues compared with 3-dimensional conformal radiotherapy (3DCRT). At one year follow-up, the patient remained free of any obvious radiation complications. Image guided IMRT provides better dose distribution than 3DCRT in retinoblastoma eyes, delivering the therapeutic dose to the tumours and minimizing adjacent tissue damage

A TCP model for external beam treatment of intermediate-risk prostate cancer.

LENUS (Irish Health Repository)

Walsh, Seán

2013-03-01

Biological models offer the ability to predict clinical outcomes. The authors describe a model to predict the clinical response of intermediate-risk prostate cancer to external beam radiotherapy for a variety of fractionation regimes.

Multicenter study differentiated thyroid carcinoma (MSDS). Diminished acceptance of adjuvant external beam radiotherapy

International Nuclear Information System (INIS)

Biermann, M.; Pixberg, M.K.; Schober, O.; Schuck, A.; Willich, N.; Heinecke, A.; Koepke, W.; Schmid, K.W.; Dralle, H.

2003-01-01

Aim: The Multicenter Study Differentiated Thyroid Carcinoma (MSDS) is an ongoing study in Germany, Austria, and Switzerland on the clinical benefit of adjuvant external beam radiotherapy (RTx) for locally invasive differentiated thyroid carcinoma (DTC) in TNM stages pT4 pNO/1/xMO/x (5th ed. 1997). Methods: MSDS was designed as a prospective randomized trial. Patients receive thyroidectomy, radioiodine therapy (RIT) to ablate the thyroid remnant, and TSH-suppressive L-thyroxine therapy with or without RTx after documented elimination of cervical iodine-131 uptake (http://msds-studie.uni-muenster.de). Results: 311 patients were enrolled between January 2000 and March 2003. 279 patients met the trial's inclusion criteria. 45 consented to randomization, of whom 17 were randomized into treatment arm A (RTx) and 18 into arm B (no RTx). Advised by the trial's independent Data Monitoring and Safety Committee, the MSDS steering committee decided to terminate randomization in April 2003 and continue MSDS as a prospective cohort study. 23 of the 234 patients in the observation arm of the trial were prescribed RTx by their physicians. Thus, 14% of the trial cohort were randomized or assigned to receive RTx (intention-to-treat analysis). In contrast, at least 44% of all patients with pT4 papillary DTC in Germany in the nationwide PCES study underwent RTx in 1996 (p 2 -test). Conclusions: Acceptance of external beam RTx as a treatment modality for DTC has receded to a degree that accrual of a sufficient number of patients for a randomized trial has been impossible. Observation of the trial cohort is continued in order to assess clinical event rates with and without RTx and chronic RTx toxicity. (orig.) [de

Three-dimensional conformal external beam radiotherapy compared with permanent prostate implantation in low-risk prostate cancer based on endorectal magnetic resonance spectroscopy imaging and prostate-specific antigen level

International Nuclear Information System (INIS)

Pickett, Barby; Kurhanewicz, John; Pouliot, Jean; Weinberg, Vivian; Shinohara, Katsuto; Coakley, Fergus; Roach, Mack

2006-01-01

Purpose: To evaluate the metabolic response by comparing the time to resolution of spectroscopic abnormalities (TRSA) and the time to prostate-specific antigen level in low-risk prostate cancer patients after treatment with three-dimensional conformal external beam radiotherapy (3D-CRT) compared with permanent prostate implantation (PPI). Recent studies have suggested that the treatment of low-risk prostate cancer yields similar results for patients treated with 3D-CRT or PPI. Methods and Materials: A total of 50 patients, 25 in each group, who had been treated with 3D-CRT or PPI, had undergone endorectal magnetic resonance spectroscopy imaging before and/or at varying times after therapy. The 3D-CRT patients had received radiation doses of ≥72 Gy compared with 144 Gy for the PPI patients. The spectra from all usable voxels were examined for detectable levels of metabolic signal, and the percentages of atrophic and cancerous voxels were tabulated. Results: The median time to resolution of the spectroscopic abnormalities was 32.2 and 24.8 months and the time to the nadir prostate-specific antigen level was 52.4 and 38.0 months for the 3D-CRT and PPI patients, respectively. Of the 3D-CRT patients, 92% achieved negative endorectal magnetic resonance spectroscopy imaging findings, with 40% having complete metabolic atrophy. All 25 PPI patients had negative endorectal magnetic resonance spectroscopy imaging findings, with 60% achieving complete metabolic atrophy. Conclusion: The results of this study suggest that metabolic and biochemical responses of the prostate are more pronounced after PPI. Our results have not proved PPI is more effective at curing prostate cancer, but they have demonstrated that it may be more effective at destroying prostate metabolism

Sexual function after external-beam radiotherapy for prostate cancer: what do we know?

Science.gov (United States)

Incrocci, Luca

2006-02-01

Quality of life in general and sexual functioning in particular have become very important in cancer patients. Due to modern surgical techniques, improved quality of drugs for chemotherapy and very modern radiation techniques, more patients can be successfully treated without largely compromising sexual functioning. One can assume that because of the life-threatening nature of cancer, sexual activity is not important to patients and their partners, but this is not true. Prostate cancer has become the most common non-skin malignant neoplasm in older men in Western countries. In this paper, we discuss the various methods used to evaluate erectile and sexual dysfunction and the definition of potency. Data on the etiology of erectile dysfunction after external-beam radiotherapy for prostate cancer is reviewed, and the literature is been summarized. Patients should be offered sexual counseling and informed about the availability of effective treatments for erectile dysfunction, such as sildenafil, intracavernosal injection, and vacuum devices. Cancer affects quality of life and sexual function. The challenge for oncologists is to address this with compassion.

Reducing the risk of radiocarcinogenesis in paediatric patients treated with external beam radiotherapy

International Nuclear Information System (INIS)

Taylor, M.L.; Franich, R.D.; Kron, Tomas

2010-01-01

Full text: The aim of this study was to determine readily-implementable means of out-of-field dose reduction in paediatric patients undergoing external beam radiotherapy for intracranial lesions. [n this way, the risk of secondary cancer induction may be reduced. Dose measurements were taken using LiF:Mg, Cu, P TLD 1 00 H chips in a 5 year old paediatric phantom. Multiple TLDs were placed at: the right and left lenses of the eye, optic nerve, brain, thyroid, lungs, heart, kidneys, abdomen and gonads. Varian 600 C and Varian Trilogy linear accelerators, both at 6 MV, were investigated, using different delivery parameters. Most of the out-of-field dose at large distances is attributable to leakage. The difference between stereotactic and larger field sizes is less significant far from the primary field. Out-of-field dose from the Trilogy was 40% higher than the 600 e . Aligning the craniocaudal axis of the patient with the x-plane of the collimator results in a dose reduction of 40%, for both machines. - A simple shielding arrangement may halve out-of-field dose. (author)

Guide of external radiotherapy procedures 2007

International Nuclear Information System (INIS)

Anon.

2008-01-01

This work aims at participating in the permanent optimization of the returned medical service and the ratio profit-risk. This first version of the guide of external radiotherapy procedures 2007 processes only techniques of external radiotherapy, by opposition to the techniques of brachytherapy which use radioactive sources (iridium 192 , iodine 125 , cesium 137 ) placed in the contact of the tumor to be irradiated. Only, also, will be considered the irradiations of the most frequent cunning(malignant) tumors with the exception of the radiotherapy of the mild pathologies and the re-irradiations after a first radiotherapy. The first part is shared in eight chapters as follow: introduction, the steps of a treatment by radiotherapy, infrastructure, equipment and human resources, radiobiology mechanism of action of ionising radiations in radiotherapy, dose in radiotherapy, quality of treatment and radiation protection of patients in radiotherapy, prevention and risk management in radiotherapy, quality assurance and radiation protection for the pediatrics cancers and the case of pregnant women. The second part gives the tumoral localizations and the procedures; the third part is a glossary and different annexes such regulations and legislative texts. (N.C.)

Daily-diary evaluated side-effects of conformal versus conventional prostatic cancer radiotherapy technique

International Nuclear Information System (INIS)

Widmark, A.; Fransson, P.; Franzen, L.; Littbrand, B.; Henriksson, R.

1997-01-01

Conventional 4-field box radiotherapy technique induces high morbidity for patients with localized prostatic cancer. Using a patient daily diary, the present study compared side-effects after conventional radiotherapy with conformal radiotherapy for prostate cancer. Fifty-eight patients treated with the conventional technique (with or without sucralfate) were compared with 72 patients treated with conformal technique. The patient groups were compared with an age-matched control population. Patients treated with conformal technique were also evaluated regarding acute and late urinary problems. Results showed that patients treated with conformal technique reported significantly fewer side-effects as compared with conventional technique. Patients treated with sucralfate also showed slightly decreased intestinal morbidity in comparison to non-sucralfate group. Acute and late morbidity evaluated by the patients was decreased after conformal radiotherapy as compared with the conventional technique. Sucralfate may be of value if conformal radiotherapy is used for dose escalation in prostatic cancer patients. (orig.)

Post-external radiotherapy hypothyroidism: 15 cases; Hypothyroidie apres radiotherapie externe. A propos de 15 cas

Energy Technology Data Exchange (ETDEWEB)

Kaffel, N.; Mnif, M.; Abid, M. [Centre Hospitalier Universitaire Hedi Chaker, Sfax (Tunisia); Daoud, J. [Centre Hospitalier Universitaire Habib Bourguiba, Sfax (Tunisia)

2001-06-01

Post-external radiotherapy hypothyroidism: 15 cases. Hypothyroidism frequency is estimated to be between 10 and 45% after radiotherapy alone, and 40 to 67% after radiotherapy associated with thyroidectomy. This hypothyroidism is infra-clinical in 60% of the cases. Our study concerned 15 cases of hypothyroidism after external radiotherapy delivered between and 1991 and 1999. An irradiation of the cervical, cerebral and thorax regions was indicated for different types of cancers. Larynx carcinoma epidermoid was the most frequent cancer (seven cases); the radiation treatment used cobalt 60 with conventional fractionation, i.e., 2 Gy per treatment, five treatments a week. In nine cases, the hypothyroidism was discovered during a systematic examination; it was clinically evident in the six remaining cases. Hypothyroidism appeared after an irradiation dose average of 50 Gy (extremes 30-65 Gy). The average duration of the irradiation was about 7 weeks and the hypothyroidism appeared in a mean 22 months. In all cases, the substituting treatment was initiated with a favorable progression. Faced with the risk of hypothyroidism, it is necessary to check patients who have undergone external irradiation of the neck. (authors)

Conformal radiotherapy using multileaf collimation: quality assurance and in vivo dosimetry

Energy Technology Data Exchange (ETDEWEB)

Aletti, P [Centre A. Vautrin, Nancy (France)

1995-12-01

The application of quality assurance principles in three dimensional conformal therapy is discussed.Critical requirements in three dimensional radiotherapy are the patient immobilization, the location, and the delivered dose. General recommendations with respect to the equipment for conformal radiotherapy and personnel are made.

Conformal radiotherapy using multileaf collimation: quality assurance and in vivo dosimetry

International Nuclear Information System (INIS)

Aletti, P.

1995-01-01

The application of quality assurance principles in three dimensional conformal therapy is discussed.Critical requirements in three dimensional radiotherapy are the patient immobilization, the location, and the delivered dose. General recommendations with respect to the equipment for conformal radiotherapy and personnel are made

QA programme in external radiotherapy in Romania - status and perspective

International Nuclear Information System (INIS)

Dumitrescu, A.; Milu, C.

2008-01-01

Full text: Recognizing the importance of quality assurance in radiotherapy and the need to make access to radiation standards traceable to the international measurement system for every radiotherapy center, the Romanian national secondary standard dosimetry laboratory (SSDL) has started in 1999 - together with IAEA - a national quality audit programme in all the centers for external radiotherapy from Romania. At present, there are 17 radiotherapy centers in Romania, and a total of 19 teletherapy units and 4 LINCs. The programme has 3 phases: the first phase was to organize a survey in all radiotherapy centers, to collect general information on their radio therapists, medical physicists, type of equipment, dosimeters, etc. Following the survey, a quality assurance network was set up, and on-site dosimetry reviews were arranged according to a suitable timetable. The second phase consisted in performing the reference dosimetry and the calibration of the equipment. Then, a quality audit system based on mailed TLDs has been applied to all radiation beams produced by cobalt-60 therapy units and medical accelerators, in order to identify discrepancies in dosimetry larger than ± 3%. At the same time, the beam calibration performed by the SSDLs was verified. The results of the first survey were analyzed, and corrective actions were taken. A second survey was then organized, based on the mailed TLDs. This paper presents in detail the entire QA programme, its results, and the actions that are to be taken in order to improve the accuracy and consistency of the dosimetry in clinical radiotherapy in Romania. (author)

Simulation and radiation treatment in external radiotherapy

International Nuclear Information System (INIS)

Singer, E.

1996-01-01

It is well known that in order to obtain a uniform dose in the treated volume as defined in ICRU 50, there should be a 10% maximum difference between maximum and minimum dose values in treatment planning. Clinical target volume (CTV) should be related to external areas of body sections where tumour is located. These areas are important because different radiation beams enter through them. Therefore, verification of the planning target volume (PTV) through the external areas is highly significant. In this work we point out the importance of controlling that PTV is irradiated as planned considering some error sources usually found in radiotherapy practice with equipment that has been intensively used for a long time. Moreover, I think this experience will be helpful for those centers around the world where radiation treatment is carried out with reconditioned units. (author)

Simulation and radiation treatment in external radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Singer, E [Mevaterapia Medical Center, Buenos Aires (Argentina)

1996-08-01

It is well known that in order to obtain a uniform dose in the treated volume as defined in ICRU 50, there should be a 10% maximum difference between maximum and minimum dose values in treatment planning. Clinical target volume (CTV) should be related to external areas of body sections where tumour is located. These areas are important because different radiation beams enter through them. Therefore, verification of the planning target volume (PTV) through the external areas is highly significant. In this work we point out the importance of controlling that PTV is irradiated as planned considering some error sources usually found in radiotherapy practice with equipment that has been intensively used for a long time. Moreover, I think this experience will be helpful for those centers around the world where radiation treatment is carried out with reconditioned units. (author).

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

Adaptive-Predictive Organ Localization Using Cone-Beam Computed Tomography for Improved Accuracy in External Beam Radiotherapy for Bladder Cancer

International Nuclear Information System (INIS)

Lalondrelle, Susan; Huddart, Robert; Warren-Oseni, Karole; Hansen, Vibeke Nordmark; McNair, Helen; Thomas, Karen; Dearnaley, David; Horwich, Alan; Khoo, Vincent

2011-01-01

Purpose: To examine patterns of bladder wall motion during high-dose hypofractionated bladder radiotherapy and to validate a novel adaptive planning method, A-POLO, to prevent subsequent geographic miss. Methods and Materials: Patterns of individual bladder filling were obtained with repeat computed tomography planning scans at 0, 15, and 30 minutes after voiding. A series of patient-specific plans corresponding to these time-displacement points was created. Pretreatment cone-beam computed tomography was performed before each fraction and assessed retrospectively for adaptive intervention. In fractions that would have required intervention, the most appropriate plan was chosen from the patient's 'library,' and the resulting target coverage was reassessed with repeat cone-beam computed tomography. Results: A large variation in patterns of bladder filling and interfraction displacement was seen. During radiotherapy, predominant translations occurred cranially (maximum 2.5 cm) and anteriorly (maximum 1.75 cm). No apparent explanation was found for this variation using pretreatment patient factors. A need for adaptive planning was demonstrated by 51% of fractions, and 73% of fractions would have been delivered correctly using A-POLO. The adaptive strategy improved target coverage and was able to account for intrafraction motion also. Conclusions: Bladder volume variation will result in geographic miss in a high proportion of delivered bladder radiotherapy treatments. The A-POLO strategy can be used to correct for this and can be implemented from the first fraction of radiotherapy; thus, it is particularly suited to hypofractionated bladder radiotherapy regimens.

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

Neoadjuvant hormonal therapy and external-beam radiotherapy versus external-beam irradiation alone for prostate cancer. A quality-of-life analysis

Energy Technology Data Exchange (ETDEWEB)

Pinkawa, Michael; Piroth, Marc D.; Asadpour, Branka; Gagel, Bernd; Fischedick, Karin; Siluschek, Jaroslav; Kehl, Mareike; Krenkel, Barbara; Eble, Michael J. [RWTH Aachen (Germany). Dept. of Radiotherapy

2009-02-15

To evaluate the impact of neoadjuvant hormonal therapy (NHT) on quality of life after external-beam radiotherapy (EBRT) for prostate cancer. A group of 170 patients (85 with and 85 without NHT) has been surveyed prospectively before EBRT (70.2-72 Gy), at the last day of EBRT, a median time of 2 months and 15 months after EBRT using a validated questionnaire (Expanded Prostate Cancer Index Composite). Pairs with and without NHT (median treatment time of 3.5 months before EBRT) were matched according to the respective planning target volume and prostate volume. Before EBRT, significantly lower urinary function/bother, sexual function and hormonal function/bother scores were found for patients with NHT. More than 1 year after EBRT, only sexual function scores remained lower. In a multivariate analysis, NHT and adjuvant hormonal therapy (HT) versus NHT only (hazard ratio 14; 95% confidence interval 2.7-183; p = 0.02) and luteinizing hormone-releasing hormone (LHRH) agonists versus antiandrogens (hazard ratio 3.6; 95% confidence interval 1.1-12; p = 0.04) proved to be independent risk factors for long-term erectile dysfunction (no or very poor ability to have an erection). With the exception of sexual function (additional adjuvant HT and application of LHRH analog independently adverse), short-term NHT was not found to decrease quality of life after EBRT for prostate cancer. (orig.)

Experimental assessment of out-of-field dose components in high energy electron beams used in external beam radiotherapy.

Science.gov (United States)

Alabdoaburas, Mohamad M; Mege, Jean-Pierre; Chavaudra, Jean; Bezin, Jérémi Vũ; Veres, Atilla; de Vathaire, Florent; Lefkopoulos, Dimitri; Diallo, Ibrahima

2015-11-08

The purpose of this work was to experimentally investigate the out-of-field dose in a water phantom, with several high energy electron beams used in external beam radiotherapy (RT). The study was carried out for 6, 9, 12, and 18 MeV electron beams, on three different linear accelerators, each equipped with a specific applicator. Measurements were performed in a water phantom, at different depths, for different applicator sizes, and off-axis distances up to 70 cm from beam central axis (CAX). Thermoluminescent powder dosimeters (TLD-700) were used. For given cases, TLD measurements were compared to EBT3 films and parallel-plane ionization chamber measurements. Also, out-of-field doses at 10 cm depth, with and without applicator, were evaluated. With the Siemens applicators, a peak dose appears at about 12-15 cm out of the field edge, at 1 cm depth, for all field sizes and energies. For the Siemens Primus, with a 10 × 10 cm(²) applicator, this peak reaches 2.3%, 1%, 0.9% and 1.3% of the maximum central axis dose (Dmax) for 6, 9, 12 and 18 MeV electron beams, respectively. For the Siemens Oncor, with a 10 × 10 cm(²) applicator, this peak dose reaches 0.8%, 1%, 1.4%, and 1.6% of Dmax for 6, 9, 12, and 14 MeV, respectively, and these values increase with applicator size. For the Varian 2300C/D, the doses at 12.5 cm out of the field edge are 0.3%, 0.6%, 0.5%, and 1.1% of Dmax for 6, 9, 12, and 18 MeV, respectively, and increase with applicator size. No peak dose is evidenced for the Varian applicator for these energies. In summary, the out-of-field dose from electron beams increases with the beam energy and the applicator size, and decreases with the distance from the beam central axis and the depth in water. It also considerably depends on the applicator types. Our results can be of interest for the dose estimations delivered in healthy tissues outside the treatment field for the RT patient, as well as in studies exploring RT long-term effects.

The effect of aerobic exercise on treatment-related acute toxicity in men receiving radical external beam radiotherapy for localised prostate cancer.

Science.gov (United States)

Kapur, G; Windsor, P M; McCowan, C

2010-09-01

We retrospectively analysed acute radiation toxicity data for patients who had participated in a randomised controlled study in our centre in order to assess the impact of aerobic exercise on acute rectal and bladder morbidity during treatment. Data from 65 of 66 patients were analysed: 33 allocated into a control group (standard advice) and 33 into an exercise group (aerobic walking for 30 min at least three times per week) during 4 weeks of external beam radiotherapy; one patient in the exercise group withdrew after randomisation before starting radiotherapy. There was a trend towards less severe acute rectal toxicity in the exercise group with a statistically significant difference in mean toxicity scores over the 4 weeks of radiotherapy (P=0.004), with no significant difference in bladder toxicity scores between the two groups (P=0.123). The lack of an association for severity of bladder toxicity could be attributed to the confounding effect of lower urinary tract symptoms from their prostate cancer. Keeping active and being asked to adhere to a well-defined exercise schedule appears to reduce the severity of rectal toxicity during radiotherapy to the prostate.

Sildenafil citrate (Viagra) and erectile dysfunction following external beam radiotherapy for prostate cancer: a randomized, double-blind, placebo-controlled, cross-over study

International Nuclear Information System (INIS)

Incrocci, Luca; Koper, Peter C.M.; Hop, Wim C.J.; Slob, A. Koos

2001-01-01

Purpose: To determine the efficacy of sildenafil citrate (Viagra) in patients with erectile dysfunction after three-dimensional conformal external beam radiotherapy (3D-CRT) for prostate cancer. Methods and Materials: 406 patients with complaints of erectile dysfunction and who completed radiation at least 6 months before the study were approached by mail. 3D-CRT had been delivered (mean dose 68 Gy). Sixty patients were included and entered a double-blind, placebo-controlled, cross-over study lasting 12 weeks. They received during 2 weeks 50 mg of sildenafil or placebo; at Week 2 the dose was increased to 100 mg in case of unsatisfactory erectile response. At Week 6, patients crossed over to the alternative treatment. Data were collected using the International Index of Erectile Function (IIEF) questionnaire, and side effects were recorded. Results: Mean age was 68 years. All patients completed the study. For most questions of the IIEF questionnaire there was a significant increase in mean scores from baseline with sildenafil, but not with placebo. Ninety percent of the patients needed a dose adjustment to 100 mg sildenafil. Side effects were mild or moderate. Conclusion: Sildenafil is well tolerated and effective in improving erectile function of patients with ED after 3D-CRT for prostate cancer

Skin markings in external radiotherapy by temporary tattooing with henna: Improvement of accuracy and increased patient comfort

International Nuclear Information System (INIS)

Wurstbauer, Karl; Sedlmayer, Felix; Kogelnik, H. Dieter

2001-01-01

Purpose: To guarantee invariable skin markings in patients undergoing a course of external radiotherapy, especially using conformal techniques. Cutaneous markings with henna also increase patient comfort, because washing and showering are allowed. Methods and Materials: Henna, a completely natural product, is a skin colorant with a history of 5,000 years. It is applied to the skin in the form of a paste. While drying, henna stains the superficial skin layers for several weeks, and the marked area can be exposed to water arbitrarily. In case of fading of the stain before the end of radiotherapy, the marking procedure can be repeated. From November 1998 until March 2000, we performed skin markings with henna in 158 patients with different tumor sites. The majority of patients received conformal radiotherapy techniques. All patients have been evaluated concerning durability of the markings, the required number of marking procedures per treatment course, and possible related side effects. Results: The median durability of henna staining is 23 days (range 12-48 days). On average, two marking procedures (range 1-4) are necessary for a patient treated with curative intent. Although washing and showering are freely permitted, no adverse cutaneous side effects (e.g., erythema, allergic reactions) have been observed. Conclusions: Skin marking by temporary tattooing with henna increases the accuracy of external radiotherapy. It yields stable and invariable markings for the entire course of radiotherapy and also increases the comfort of patients

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

3D-Conformal Versus Intensity-Modulated Postoperative Radiotherapy of Vaginal Vault: A Dosimetric Comparison

International Nuclear Information System (INIS)

Cilla, Savino; Macchia, Gabriella; Digesu, Cinzia; Deodato, Francesco; Romanella, Michele; Ferrandina, Gabriella; Padula, Gilbert; Picardi, Vincenzo; Scambia, Giovanni; Piermattei, Angelo; Morganti, Alessio Giuseppe

2010-01-01

We evaluated a step-and-shoot IMRT plan in the postoperative irradiation of the vaginal vault compared with equispaced beam arrangements (3-5) 3D-radiotherapy (RT) optimized plans. Twelve patients were included in this analysis. Four plans for each patient were compared in terms of dose-volume histograms, homogeneity index (HI), and conformity index (CI): (1) 3 equispaced beam arrangement 3D-RT; (2) 4 equispaced beam arrangement 3D-RT; (3) 5 equispaced beam arrangement 3D-RT; (4) step-and-shoot IMRT technique. CI showed a good discrimination between the four plans. The mean scores of CI were 0.58 (range: 0.38-0.67) for the 3F-CRT plan, 0.58 (range: 0.41-0.66) for 4F-CRT, 0.62 (range: 0.43-0.68) for 5F-CRT and 0.69 (range: 0.58-0.78) for the IMRT plan. A significant improvement of the conformity was reached by the IMRT plan (p mean , V90%, V95%, V100% was recorded for rectal and bladder irradiation with the IMRT plan. Surprisingly, IMRT supplied a significant dose reduction also for rectum and bladder V30% and V50%. A significant dosimetric advantage of IMRT over 3D-RT in the adjuvant treatment of vaginal vault alone in terms of treatment conformity and rectum and bladder sparing is shown.

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.

Preoperative external beam radiotherapy and reduced dose brachytherapy for carcinoma of the cervix: survival and pathological response

International Nuclear Information System (INIS)

Jacinto, Alexandre A; Maia, Maria AC; Fogaroli, Ricardo C; Castilho, Marcus S; Novaes, Paulo ERS; Novick, Pablo R; Viani, Gustavo A; Salvajoli, João V; Ferrigno, Robson; Pellizzon, Antonio Cássio A; Lima, Stella SS

2007-01-01

To evaluate the pathologic response of cervical carcinoma to external beam radiotherapy (EBRT) and high dose rate brachytherapy (HDRB) and outcome. Between 1992 and 2001, 67 patients with cervical carcinoma were submitted to preoperative radiotherapy. Sixty-five patients were stage IIb. Preoperative treatment included 45 Gy EBRT and 12 Gy HDRB. Patients were submitted to surgery after a mean time of 82 days. Lymphadenectomy was performed in 81% of patients. Eleven patients with residual cervix residual disease on pathological specimen were submitted to 2 additional insertions of HDRB. median follow up was 72 months. Five-year cause specific survival was 75%, overall survival 65%, local control 95%. Complete pelvic pathological response was seen in 40%. Surgery performed later than 80 days was associated with pathological response. Pelvic nodal involvement was found in 12%. Complete pelvic pathological response and negative lymphnodes were associated with better outcome (p = .03 and p = .005). Late grade 3 and 4 urinary and intestinal adverse effects were seen in 12 and 2% of patients. Time allowed between RT and surgery correlated with pathological response. Pelvic pathological response was associated with improved outcome. Postoperative additional HDRB did not improve therapeutic results. Treatment was well tolerated

Non small cells stage I bronchial cancers: three-dimensional radiotherapy and radiotherapy in stereotactic conditions; Cancers bronchiques non a petites cellules de stade I: radiotherapie tridimensionnelle et radiotherapie en conditions stereotaxiques

Energy Technology Data Exchange (ETDEWEB)

Schipman, B.; Bosset, J.F. [CHU, 25 - Besancon (France); Marchesi, V.; Beckendorf, V.; Desandes, E.; Peiffert, D. [CRLCC Alexis-Vautrin, 54 - Vandaeuvre-les-Nancy (France); Bosset, M. [CHU, 26 - Valence (France)

2010-10-15

The authors report a comparison between three-dimensional conformation radiotherapy and robotic irradiation in stereotactic conditions (with CyberKnife) for patients suffering from a bronchial cancer with no small cells of stage I. Acute and late toxicity have been recorded, and the monitoring comprised a clinic examination and a thoracic scanography. The external radiotherapy results in an important local control rate and an acceptable toxicity. Some prospective studies are still needed to compare three-dimensional conformation respiratory-gated radiotherapy and radiotherapy in stereotactic conditions. Short communication

Optimum location of external markers using feature selection algorithms for real-time tumor tracking in external-beam radiotherapy: a virtual phantom study.

Science.gov (United States)

Nankali, Saber; Torshabi, Ahmad Esmaili; Miandoab, Payam Samadi; Baghizadeh, Amin

2016-01-08

In external-beam radiotherapy, using external markers is one of the most reliable tools to predict tumor position, in clinical applications. The main challenge in this approach is tumor motion tracking with highest accuracy that depends heavily on external markers location, and this issue is the objective of this study. Four commercially available feature selection algorithms entitled 1) Correlation-based Feature Selection, 2) Classifier, 3) Principal Components, and 4) Relief were proposed to find optimum location of external markers in combination with two "Genetic" and "Ranker" searching procedures. The performance of these algorithms has been evaluated using four-dimensional extended cardiac-torso anthropomorphic phantom. Six tumors in lung, three tumors in liver, and 49 points on the thorax surface were taken into account to simulate internal and external motions, respectively. The root mean square error of an adaptive neuro-fuzzy inference system (ANFIS) as prediction model was considered as metric for quantitatively evaluating the performance of proposed feature selection algorithms. To do this, the thorax surface region was divided into nine smaller segments and predefined tumors motion was predicted by ANFIS using external motion data of given markers at each small segment, separately. Our comparative results showed that all feature selection algorithms can reasonably select specific external markers from those segments where the root mean square error of the ANFIS model is minimum. Moreover, the performance accuracy of proposed feature selection algorithms was compared, separately. For this, each tumor motion was predicted using motion data of those external markers selected by each feature selection algorithm. Duncan statistical test, followed by F-test, on final results reflected that all proposed feature selection algorithms have the same performance accuracy for lung tumors. But for liver tumors, a correlation-based feature selection algorithm, in

Non-rigid CT/CBCT to CBCT registration for online external beam radiotherapy guidance

Science.gov (United States)

Zachiu, Cornel; de Senneville, Baudouin Denis; Tijssen, Rob H. N.; Kotte, Alexis N. T. J.; Houweling, Antonetta C.; Kerkmeijer, Linda G. W.; Lagendijk, Jan J. W.; Moonen, Chrit T. W.; Ries, Mario

2018-01-01

Image-guided external beam radiotherapy (EBRT) allows radiation dose deposition with a high degree of accuracy and precision. Guidance is usually achieved by estimating the displacements, via image registration, between cone beam computed tomography (CBCT) and computed tomography (CT) images acquired at different stages of the therapy. The resulting displacements are then used to reposition the patient such that the location of the tumor at the time of treatment matches its position during planning. Moreover, ongoing research aims to use CBCT-CT image registration for online plan adaptation. However, CBCT images are usually acquired using a small number of x-ray projections and/or low beam intensities. This often leads to the images being subject to low contrast, low signal-to-noise ratio and artifacts, which ends-up hampering the image registration process. Previous studies addressed this by integrating additional image processing steps into the registration procedure. However, these steps are usually designed for particular image acquisition schemes, therefore limiting their use on a case-by-case basis. In the current study we address CT to CBCT and CBCT to CBCT registration by the means of the recently proposed EVolution registration algorithm. Contrary to previous approaches, EVolution does not require the integration of additional image processing steps in the registration scheme. Moreover, the algorithm requires a low number of input parameters, is easily parallelizable and provides an elastic deformation on a point-by-point basis. Results have shown that relative to a pure CT-based registration, the intrinsic artifacts present in typical CBCT images only have a sub-millimeter impact on the accuracy and precision of the estimated deformation. In addition, the algorithm has low computational requirements, which are compatible with online image-based guidance of EBRT treatments.

The use of Monte-Carlo codes for treatment planning in external-beam radiotherapy

International Nuclear Information System (INIS)

Alan, E.; Nahum, PhD.

2003-01-01

Monte Carlo simulation of radiation transport is a very powerful technique. There are basically no exact solutions to the Boltzmann transport equation. Even, the 'straightforward' situation (in radiotherapy) of an electron beam depth-dose distribution in water proves to be too difficult for analytical methods without making gross approximations such as ignoring energy-loss straggling, large-angle single scattering and Bremsstrahlung production. monte Carlo is essential when radiation is transport from one medium into another. As the particle (be it a neutron, photon, electron, proton) crosses the boundary then a new set of interaction cross-sections is simply read in and the simulation continues as though the new medium were infinite until the next boundary is encountered. Radiotherapy involves directing a beam of megavoltage x rays or electrons (occasionally protons) at a very complex object, the human body. Monte Carlo simulation has proved in valuable at many stages of the process of accurately determining the distribution of absorbed dose in the patient. Some of these applications will be reviewed here. (Rogers and al 1990; Andreo 1991; Mackie 1990). (N.C.)

SU-G-TeP3-06: Nanoparticle-Aided External Beam Radiotherapy Leveraging the Cerenkov Effect

Energy Technology Data Exchange (ETDEWEB)

Ouyang, Z; Ngwa, W [University of Massachusetts Lowell, Lowell, MA (United States); Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School (United States); Liu, B; Sajo, E [University of Massachusetts Lowell, Lowell, MA (United States); Yasmin-Karim, S [Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School (United States)

2016-06-15

Purpose: This study investigates the feasibility of exploiting the Cerenkov radiation (CR) present during external beam radiotherapy (EBRT) for significant therapeutic gain, using titanium dioxide nanoparticles (titania) delivered via a new design of radiotherapy biomaterials. Methods: Recently published work has shown that CR generated by radionuclides during PET imaging could substantially enhance damage to cancer cells in the presence of 0.625 µg/g titania. We hypothesize that equal or greater damage can be achieved during EBRT. To test this hypothesis, Monte Carlo simulation was done using GEANT4 in order to get the total CR yield inside a tumor volume during EBRT compared to that of the radionuclides. We considered a novel approach where a sufficiently potent concentration of the titania was delivered directly into the tumor using radiotherapy biomaterials (e.g. fiducials) loaded with the titania. The intra-tumor distribution/diffusion of titania released from the fiducials was calculated. An in-vitro MTS assay experiment was also carried out to establish the relative non-toxicity of titania for concentrations of up to 1 µg/g. Results: For a radiotherapy biomaterial loaded with 15 µg/g of 2-nm titania, at least 0.625 µg/g could be delivered through out a tumor sub-volume of 2-cm diameter after 14 days. This concentration level could inflict substantial damage to tumor cells during EBRT. The Monte Carlo results showed the CR yield in tumor by 6 MV radiation was higher than the radionuclides and hence potentially greater damage may be obtained during EBRT. No significant cell viability change was observed for 1 µg/g titania. Conclusion: Altogether, these preliminary findings demonstrate a potential new approach that can be used to take advantage of the CR present during megavoltage EBRT to boost damage to tumor cells. The results provide significant impetus for further experimental studies towards development of nanoparticle-aided EBRT powered by the

Conformal radiotherapy: a glossary

International Nuclear Information System (INIS)

Dubray, B.; Giraud, P.; Beaudre, A.

1999-01-01

Most of the concepts and terms related to conformal radiotherapy were produced by English-speaking authors and eventually validated by international groups of experts, whose working language was also English. Therefore, a significant part of this literature is poorly accessible to the French-speaking radiation oncology community. The present paper gathers the 'official' definitions already published in French, along with propositions for the remaining terms which should be submitted to a more formal and representative validation process. (author)

Proton external beam in the TANDAR Accelerator

International Nuclear Information System (INIS)

Rey, R.; Schuff, J.A.; Perez de la Hoz, A.; Debray, M.E.; Hojman, D.; Kreiner, A.J.; Kesque, J.M.; Saint-Martin, G.; Oppezzo, O.; Bernaola, O.A.; Molinari, B.L.; Duran, H.A.; Policastro, L.; Palmieri, M.; Ibanez, J.; Stoliar, P.; Mazal, A.; Caraballo, M.E.; Burlon, A.; Cardona, M.A.; Vazquez, M.E.; Salfity, M.F.; Ozafran, M.J.; Naab, F.; Levinton, G.; Davidson, M.; Buhler, M.

1998-01-01

An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm 2 approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

Post-external radiotherapy hypothyroidism: 15 cases

International Nuclear Information System (INIS)

Kaffel, N.; Mnif, M.; Abid, M.; Daoud, J.

2001-01-01

Post-external radiotherapy hypothyroidism: 15 cases. Hypothyroidism frequency is estimated to be between 10 and 45% after radiotherapy alone, and 40 to 67% after radiotherapy associated with thyroidectomy. This hypothyroidism is infra-clinical in 60% of the cases. Our study concerned 15 cases of hypothyroidism after external radiotherapy delivered between and 1991 and 1999. An irradiation of the cervical, cerebral and thorax regions was indicated for different types of cancers. Larynx carcinoma epidermoid was the most frequent cancer (seven cases); the radiation treatment used cobalt 60 with conventional fractionation, i.e., 2 Gy per treatment, five treatments a week. In nine cases, the hypothyroidism was discovered during a systematic examination; it was clinically evident in the six remaining cases. Hypothyroidism appeared after an irradiation dose average of 50 Gy (extremes 30-65 Gy). The average duration of the irradiation was about 7 weeks and the hypothyroidism appeared in a mean 22 months. In all cases, the substituting treatment was initiated with a favorable progression. Faced with the risk of hypothyroidism, it is necessary to check patients who have undergone external irradiation of the neck. (authors)

Conformal fields in prostate radiotherapy: A comparison between measurement, calculation and simulation

Directory of Open Access Journals (Sweden)

Seied R Mahdavi

2012-01-01

Full Text Available Aims: The objective of this study is to evaluate the accuracy of a treatment planning system (TPS for calculating the dose distribution parameters in conformal fields (CF. Dosimetric parameters of CF′s were compared between measurement, Monte Carlo simulation (MCNP4C and TPS calculation. Materials and Methods: Field analyzer water phantom was used for obtaining percentage depth dose (PDD curves and beam profiles (BP of different conformal fields. MCNP4C was used to model conformal fields dose specification factors and head of linear accelerator varian model 2100C/D. Results: Results showed that the distance to agreement (DTA and dose difference (DD of our findings were well within the acceptance criteria of 3 mm and 3%, respectively. Conclusions: According to this study it can be revealed that TPS using equivalent tissue air ratio calculation method is still convenient for dose prediction in non small conformal fields normally used in prostate radiotherapy. It was also showed that, since there is a close correlation with Monte Carlo simulation, measurements and TPS, Monte Carlo can be further confirmed for implementation and calculation dose distribution in non standard and complex conformal irradiation field for treatment planning systems.

Film dosimetry in conformal radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Danciu, C; Proimos, B S [Patras Univ. (Greece). Dept. of Medical Physics

1995-12-01

Dosimetry, through a film sandwiched in a transverse cross-section of a solid phantom, is a method of choice in Conformal Radiotherapy because: (a) the blackness (density) of the film at each point offers a measure of the total dose received at that point, and (b) the film is easily calibrated by exposing a film strip in the same cross-section, through a stationary field. The film must therefore have the following properties: (a) it must be slow, in order not to be overexposed, even at a therapeutic dose of 200 cGy, and (b) the response of the film (density versus dose curve) must be independent of the photon energy spectrum. A few slow films were compared. It was found that the Kodak X-Omat V for therapy verification was the best choice. To investigate whether the film response was independent of the photon energy, response curves for six depths, starting from the depth of maximum dose to the depth of 25 cm, in solid phantom were derived. The vertical beam was perpendicular to the anterior surface of the phantom, which was at the distance of 100 cm from the source and the field was 15x15 cm at that distance. This procedure was repeated for photon beams emitted by a Cobalt-60 unit, two 6 MV and 15 MV Linear Accelerators, as well as a 45 MV Betatron. For each of those four different beams the film response was the same for all six depths. The results, as shown in the diagrams, are very satisfactory. The response curve under a geometry similar to that actually applied, when the film is irradiated in a transverse cross-section of the phantom, was derived. The horizontal beam was almost parallel (angle of 85) to the plane of the film. The same was repeated with the central ray parallel to the film (angle 90) and at a distance of 1.5 cm from the horizontal film. The field size was again 15x15 at the lateral entrance surface of the beam. The response curves remained the same, as when the beam was perpendicular to the films.

Health-Related Quality of Life 2 Years After Treatment With Radical Prostatectomy, Prostate Brachytherapy, or External Beam Radiotherapy in Patients With Clinically Localized Prostate Cancer

International Nuclear Information System (INIS)

Ferrer, Montserrat; Suarez, Jose Francisco; Guedea, Ferran; Fernandez, Pablo; Macias, Victor; Marino, Alfonso; Hervas, Asuncion; Herruzo, Ismael; Ortiz, Maria Jose; Villavicencio, Humberto; Craven-Bratle, Jordi; Garin, Olatz; Aguilo, Ferran

2008-01-01

Purpose: To compare treatment impact on health-related quality of life (HRQL) in patients with localized prostate cancer, from before treatment to 2 years after the intervention. Methods and Materials: This was a longitudinal, prospective study of 614 patients with localized prostate cancer treated with radical prostatectomy (134), three-dimensional external conformal radiotherapy (205), and brachytherapy (275). The HRQL questionnaires administered before and after treatment (months 1, 3, 6, 12, and 24) were the Medical Outcomes Study 36-Item Short Form, the Functional Assessment of Cancer Therapy (General and Prostate Specific), the Expanded Prostate Cancer Index Composite (EPIC), and the American Urological Association Symptom Index. Differences between groups were tested by analysis of variance and within-group changes by univariate repeated-measures analysis of variance. Generalized estimating equations (GEE) models were constructed to assess between-group differences in HRQL at 2 years of follow-up after adjusting for clinical variables. Results: In each treatment group, HRQL initially deteriorated after treatment with subsequent partial recovery. However, some dimension scores were still significantly lower after 2 years of treatment. The GEE models showed that, compared with the brachytherapy group, radical prostatectomy patients had worse EPIC sexual summary and urinary incontinence scores (-20.4 and -14.1; p < 0.001), and external radiotherapy patients had worse EPIC bowel, sexual, and hormonal summary scores (-3.55, -5.24, and -1.94; p < 0.05). Prostatectomy patients had significantly better EPIC urinary irritation scores than brachytherapy patients (+4.16; p < 0.001). Conclusions: Relevant differences between treatment groups persisted after 2 years of follow-up. Radical prostatectomy had a considerable negative effect on sexual functioning and urinary continence. Three-dimensional conformal radiotherapy had a moderate negative impact on bowel

A Dosimetric Comparison of Accelerated Partial Breast Irradiation Techniques: Multicatheter Interstitial Brachytherapy, Three-Dimensional Conformal Radiotherapy, and Supine Versus Prone Helical Tomotherapy

International Nuclear Information System (INIS)

Patel, Rakesh R.; Becker, Stewart J.; Das, Rupak K.; Mackie, Thomas R.

2007-01-01

Purpose: To compare dosimetrically four different techniques of accelerated partial breast irradiation (APBI) in the same patient. Methods and Materials: Thirteen post-lumpectomy interstitial brachytherapy (IB) patients underwent imaging with preimplant computed tomography (CT) in the prone and supine position. These CT scans were then used to generate three-dimensional conformal radiotherapy (3D-CRT) and prone and supine helical tomotherapy (PT and ST, respectively) APBI plans and compared with the treated IB plans. Dose-volume histogram analysis and the mean dose (NTD mean ) values were compared. Results: Planning target volume coverage was excellent for all methods. Statistical significance was considered to be a p value mean dose of 1.3 Gy 3 and 1.2 Gy 3 , respectively. Both of these methods were statistically significantly lower than the supine external beam techniques. Overall, all four methods yielded similar low doses to the heart. Conclusions: The use of IB and PT resulted in greater normal tissue sparing (especially ipsilateral breast and lung) than the use of supine external beam techniques of 3D-CRT or ST. However, the choice of APBI technique must be tailored to the patient's anatomy, lumpectomy cavity location, and overall treatment goals

Optimisation of radiotherapy for carcinoma of the parotid gland: a comparison of conventional, three-dimensional conformal, and intensity-modulated techniques

International Nuclear Information System (INIS)

Nutting, Christopher M.; Rowbottom, Carl G.; Cosgrove, Vivian P.; Henk, J. Michael; Dearnaley, David P.; Robinson, Martin H.; Conway, John; Webb, Steve

2001-01-01

Background and purpose: To compare external beam radiotherapy techniques for parotid gland tumours using conventional radiotherapy (RT), three-dimensional conformal radiotherapy (3DCRT), and intensity-modulated radiotherapy (IMRT). To optimise the IMRT techniques, and to produce an IMRT class solution. Materials and methods: The planning target volume (PTV), contra-lateral parotid gland, oral cavity, brain-stem, brain and cochlea were outlined on CT planning scans of six patients with parotid gland tumours. Optimised conventional RT and 3DCRT plans were created and compared with inverse-planned IMRT dose distributions using dose-volume histograms. The aim was to reduce the radiation dose to organs at risk and improve the PTV dose distribution. A beam-direction optimisation algorithm was used to improve the dose distribution of the IMRT plans, and a class solution for parotid gland IMRT was investigated. Results: 3DCRT plans produced an equivalent PTV irradiation and reduced the dose to the cochlea, oral cavity, brain, and other normal tissues compared with conventional RT. IMRT further reduced the radiation dose to the cochlea and oral cavity compared with 3DCRT. For nine- and seven-field IMRT techniques, there was an increase in low-dose radiation to non-target tissue and the contra-lateral parotid gland. IMRT plans produced using three to five optimised intensity-modulated beam directions maintained the advantages of the more complex IMRT plans, and reduced the contra-lateral parotid gland dose to acceptable levels. Three- and four-field non-coplanar beam arrangements increased the volume of brain irradiated, and increased PTV dose inhomogeneity. A four-field class solution consisting of paired ipsilateral coplanar anterior and posterior oblique beams (15, 45, 145 and 170 degree sign from the anterior plane) was developed which maintained the benefits without the complexity of individual patient optimisation. Conclusions: For patients with parotid gland tumours

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

Prostate specific antigen levels during and after external beam radiotherapy for localized carcinoma of the prostate: Predictor of therapeutic efficancy

International Nuclear Information System (INIS)

Rodrigus, P.; Landeghem, A.A.J. van

1992-01-01

For 105 patients with locoregional carcinoma of the prostate, prostate specific antigen (PSA) levels were evaluated before, during and after external beam radiotherapy. The median follow-up is 17 months. In 51 patients (48.5%) initial PSA levels exceeded the maximum normal value of 20 ng/ml. Nine patients kept non-declining high levels just after radiotherapy. Only one of these is free of disease. Assuming PSA levels decrease exponentially during radiotherapy, a mean half-life of 62 days (median 54, SD 26 days) was calculated. Three out of five patients with a PSA half-life of more than 88 days relapsed as compared to a 8% (3/37) relapse rate in patients with a 'normal' half-life. Prolonged PSA half-life suggests residual disease. PSA levels are expected to further decrease after radiation. Six months after irradiation persistent high PSA levels were found in 14/51 (27.5%) patients. Only four of them had no evidence of manifest disease. Important negative prognostic factors for disease control in our series were non-declining high levels of PSA, a PSA serum half-life exceeding 88 days and persistence of elevated PSA values longer than six months after treatment. In our opinion, PSA is a valuable marker in the follow-up of prostate cancer patients during and after radiotherapy. (orig.) [de

Knowledge-based prediction of three-dimensional dose distributions for external beam radiotherapy

International Nuclear Information System (INIS)

Shiraishi, Satomi; Moore, Kevin L.

2016-01-01

Purpose: To demonstrate knowledge-based 3D dose prediction for external beam radiotherapy. Methods: Using previously treated plans as training data, an artificial neural network (ANN) was trained to predict a dose matrix based on patient-specific geometric and planning parameters, such as the closest distance (r) to planning target volume (PTV) and organ-at-risks (OARs). Twenty-three prostate and 43 stereotactic radiosurgery/radiotherapy (SRS/SRT) cases with at least one nearby OAR were studied. All were planned with volumetric-modulated arc therapy to prescription doses of 81 Gy for prostate and 12–30 Gy for SRS. Using these clinically approved plans, ANNs were trained to predict dose matrix and the predictive accuracy was evaluated using the dose difference between the clinical plan and prediction, δD = D clin − D pred . The mean (〈δD r 〉), standard deviation (σ δD r ), and their interquartile range (IQR) for the training plans were evaluated at a 2–3 mm interval from the PTV boundary (r PTV ) to assess prediction bias and precision. Initially, unfiltered models which were trained using all plans in the cohorts were created for each treatment site. The models predict approximately the average quality of OAR sparing. Emphasizing a subset of plans that exhibited superior to the average OAR sparing during training, refined models were created to predict high-quality rectum sparing for prostate and brainstem sparing for SRS. Using the refined model, potentially suboptimal plans were identified where the model predicted further sparing of the OARs was achievable. Replans were performed to test if the OAR sparing could be improved as predicted by the model. Results: The refined models demonstrated highly accurate dose distribution prediction. For prostate cases, the average prediction bias for all voxels irrespective of organ delineation ranged from −1% to 0% with maximum IQR of 3% over r PTV ∈ [ − 6, 30] mm. The average prediction error was less

What is the value of Image guidance in external beam radiotherapy?

International Nuclear Information System (INIS)

Kron, Tomas

2010-01-01

Full text: Image guided radiation therapy (lGRT) has become available in many radiotherapy centres in Australia. It is intuitive that frequent imaging of the patient with a modality that identifies the target directly at the time of treatment delivery should benefit patients. However, TGRT is also associated with increased cost for equipment, associated training, quality assurance and imaging time. The Trans Tasman Radiation Oncology Group (TROG) has been contracted by the Australian Commonwealth Department of Health and Ageing (DoHA) to investigate a framework that could be applied to establish a cost/utility assessment of IGRT. The present work aims to develop a study that can test this for daily image guidance of prostate cancer patients. Approach Thirty intermediate risk prostate cancer patients treated at ten or more radiotherapy centres in Australia will be invited to participate. Their treatment as per local practice will not be modified; however two additional treatment plans will be created with margins that would reflect a typical margin appropriate for a treatment delivery with and without daily image guidance. Patients will be stratified for volumetric versus planar orthogonal imaging and for IMRT or conformal approaches. The outcome will be a comparison of dose volume histograms for critical structures based on equal target coverage in all plans.

Photochemical Internalization of Bleomycin Before External-Beam Radiotherapy Improves Locoregional Control in a Human Sarcoma Model

International Nuclear Information System (INIS)

Norum, Ole-Jacob; Bruland, Oyvind Sverre; Gorunova, Ludmila; Berg, Kristian

2009-01-01

Purpose: The aim of this study was to explore the tumor growth response of the combination photochemical internalization and external-beam radiotherapy. Photochemical internalization is a technology to improve the utilization of therapeutic macromolecules in cancer therapy by photochemical release of endocytosed macromolecules into the cytosol. Methods and Materials: A human sarcoma xenograft TAX-1 was inoculated subcutaneously into nude mice. The photosensitizer AlPcS 2a and bleomycin were intraperitoneally administrated 48 h and 30 min, respectively, before diode laser light exposure at 670 nm (20 J/cm 2 ). Thirty minutes or 7 days after photochemical treatment, the animals were subjected to 4 Gy of ionizing radiation. Results: Using photochemical internalization of bleomycin as an adjunct to ionizing radiation increased the time to progression for the tumors from 17 to 33 days as compared with that observed with photodynamic therapy combined with ionizing radiation as well as for radiochemotherapy with bleomycin. The side effects observed when photochemical internalization of bleomycin was given shortly before ionizing radiation were eliminated by separating the treatment modalities in time. Conclusion: Photochemical internalization of bleomycin combined with ionizing radiation increased the time to progression and showed minimal toxicity and may therefore reduce the total radiation dose necessary to obtain local tumor control while avoiding long-term sequelae from radiotherapy.

The role of radiotherapy in the management of extrahepatic bile duct cancer: an analysis of 145 consecutive patients treated with intraluminal and/or external beam radiotherapy

International Nuclear Information System (INIS)

Kamada, Tadashi; Saitou, Hiroya; Takamura, Akio; Nojima, Takayuki; Okushiba, Shun-Ichi

1996-01-01

Purpose: To determine the feasibility of high dose radiotherapy and to evaluate its role in the management of extrahepatic bile duct (EHBD) cancer. Methods and Materials: Between 1983 and 1991, 145 consecutive patients with EHBD cancer were treated by low dose rate intraluminal 192 Ir irradiation (ILRT) either alone or in combination with external beam radiotherapy (EBRT). Among the primarily irradiated, 77 patients unsuitable for surgical resection, 54 were enrolled in radical radiotherapy, and 23 received palliative radiotherapy. Fifty-nine received postoperative radiotherapy, and the remaining 9 preoperative radiotherapy. The mean radiation dose was 67.8 Gy, ranging from 10 to 135 Gy. Intraluminal 192 Ir irradiation was indicated in 103 patients, and 85 of them were combined with EBRT. Expandable metallic biliary endoprosthesis (EMBE) was used in 32 primarily irradiated patients (31 radical and 1 palliative radiotherapy) after the completion of radiotherapy. Results: The 1-, 3-, and 5-year actuarial survival rates for all 145 patients were 55%, 18%, and 10%, for the 54 patients treated by radical radiotherapy (mean 83.1 Gy), 56%, 13%, and 6% [median survival time (MST) 12.4 months], and for the 59 patients receiving postoperative radiotherapy (mean 61.6 Gy), 73%, 31%, and 18% (MST 21.5 months), respectively. Expandable metallic biliary endoprosthesis was useful for the early establishment of an internal bile passage in radically irradiated patients and MST of 14.9 months in these 31 patients was significantly longer than that of 9.3 months in the remaining 23 patients without EMBE placement (p < 0.05). Eighteen patients whose surgical margins were positive in the hepatic side bile duct(s) showed significantly better survival compared with 15 patients whose surgical margins were positive in the adjacent structure(s) (44% vs. 0% survival at 3 years, p < 0.001). No survival benefit was obtained in patients given palliative or preoperative radiotherapy

Limited Advantages of Intensity-Modulated Radiotherapy Over 3D Conformal Radiation Therapy in the Adjuvant Management of Gastric Cancer

International Nuclear Information System (INIS)

Alani, Shlomo; Soyfer, Viacheslav; Strauss, Natan; Schifter, Dan; Corn, Benjamin W.

2009-01-01

Purpose: Although chemoradiotherapy was considered the standard adjuvant treatment for gastric cancer, a recent Phase III trial (Medical Research Council Adjuvant Gastric Infusional Chemotherapy [MAGIC]) did not include radiotherapy in the randomization scheme because it was considered expendable. Given radiotherapy's potential, efforts needed to be made to optimize its use for treating gastric cancer. We assessed whether intensity-modulated radiotherapy (IMRT) could improve upon our published results in patients treated with three-dimensional (3D) conformal therapy. Methods and Materials: Fourteen patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a noncoplanar four-field arrangement. Subsequently, a nine-field IMRT plan was designed using a CMS Xio IMRT version 4.3.3 module. Two IMRT beam arrangements were evaluated: beam arrangement 1 consisted of gantry angles of 0 deg., 53 deg., 107 deg., 158 deg., 204 deg., 255 deg., and 306 deg.. Beam arrangement 2 consisted of gantry angles of 30 deg., 90 deg., 315 deg., and 345 deg.; a gantry angle of 320 deg./couch, 30 deg.; and a gantry angle of 35 o /couch, 312 o . Both the target volume coverage and the dose deposition in adjacent critical organs were assessed in the plans. Dose-volume histograms were generated for the clinical target volume, kidneys, spine, and liver. Results: Comparison of the clinical target volumes revealed satisfactory coverage by the 95% isodose envelope using either IMRT or 3D conformal therapy. However, IMRT was only marginally better than 3D conformal therapy at protecting the spine and kidneys from radiation. Conclusions: IMRT confers only a marginal benefit in the adjuvant treatment of gastric cancer and should be used only in the small subset of patients with risk factors for kidney disease or those with a preexisting nephropathy.

Limited advantages of intensity-modulated radiotherapy over 3D conformal radiation therapy in the adjuvant management of gastric cancer.

Science.gov (United States)

Alani, Shlomo; Soyfer, Viacheslav; Strauss, Natan; Schifter, Dan; Corn, Benjamin W

2009-06-01

Although chemoradiotherapy was considered the standard adjuvant treatment for gastric cancer, a recent Phase III trial (Medical Research Council Adjuvant Gastric Infusional Chemotherapy [MAGIC]) did not include radiotherapy in the randomization scheme because it was considered expendable. Given radiotherapy's potential, efforts needed to be made to optimize its use for treating gastric cancer. We assessed whether intensity-modulated radiotherapy (IMRT) could improve upon our published results in patients treated with three-dimensional (3D) conformal therapy. Fourteen patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a noncoplanar four-field arrangement. Subsequently, a nine-field IMRT plan was designed using a CMS Xio IMRT version 4.3.3 module. Two IMRT beam arrangements were evaluated: beam arrangement 1 consisted of gantry angles of 0 degrees , 53 degrees , 107 degrees , 158 degrees , 204 degrees , 255 degrees , and 306 degrees . Beam arrangement 2 consisted of gantry angles of 30 degrees , 90 degrees , 315 degrees , and 345 degrees ; a gantry angle of 320 degrees /couch, 30 degrees ; and a gantry angle of 35 degrees /couch, 312 degrees . Both the target volume coverage and the dose deposition in adjacent critical organs were assessed in the plans. Dose-volume histograms were generated for the clinical target volume, kidneys, spine, and liver. Comparison of the clinical target volumes revealed satisfactory coverage by the 95% isodose envelope using either IMRT or 3D conformal therapy. However, IMRT was only marginally better than 3D conformal therapy at protecting the spine and kidneys from radiation. IMRT confers only a marginal benefit in the adjuvant treatment of gastric cancer and should be used only in the small subset of patients with risk factors for kidney disease or those with a preexisting nephropathy.

A randomized trial comparing radical prostatectomy plus endocrine therapy versus external beam radiotherapy plus endocrine therapy for locally advanced prostate cancer. Results at median follow-up of 102 months

International Nuclear Information System (INIS)

Akakura, Koichiro; Suzuki, Hiroyoshi; Ichikawa, Tomohiko

2006-01-01

The background of this study was to investigate the optimal treatment of locally advanced prostate cancer, a prospective randomized trial was conducted to compare radical prostatectomy plus endocrine therapy versus external beam radiotherapy plus endocrine therapy. One hundred patients with T2b-3N0M0 prostate cancer were enrolled and 95 were evaluated. Of 95 cases, 46 underwent radical prostatectomy with pelvic lymph node dissection and 49 were treated with external beam radiation by linear accelerator with 40-50 Gy to the whole pelvis and 20-Gy boost to the prostatic area. For all patients, endocrine therapy was initiated 8 weeks before surgery or radiotherapy and continued thereafter. The long-term outcome and morbidity were examined. Median follow-up period was 102 months. At 10 years overall survival rates in the surgery group were better than the radiation group (76.2% versus 71.1% for biochemical progression-free rates; P=0.25, 83.5% versus 66.1% for clinical progression-free rates; P=0.14, 85.7% versus 77.1% for cause-specific survival rates; P=0.06, and 67.9% versus 60.9% for overall survival rates; P=0.30), although none of them reached statistical significance. Erectile dysfunction was recognized in almost all patients as a result of continuous endocrine therapy. Incontinence requiring more than one pad per day was observed more frequently in the surgery group than the radiation group (P<0.01). For the treatment of patients with locally advanced prostate cancer, when combined with endocrine therapy, either radical prostatectomy or external beam radiotherapy demonstrated favorable long-term outcomes. The radiation dose of 60-70 Gy might not be enough for the local treatment of locally advanced prostate cancer. (author)

The place of conformal radiotherapy in the routine work: national investigation of SFRO members'opinion

International Nuclear Information System (INIS)

Lagrange, J.L.; Lipinski, F.

2001-01-01

National French investigation of the using of conformal radiotherapy in routine work, has been made in 2001, in 180 radiotherapeutic centers. Eighty responses have been obtained and analyzed. Conformal radiotherapy is used in 88% and virtual simulation in 60% of these centers. There is a heterogeneity in the equipment of these institutions, most of them have one or two machines. The accelerator equipment differs, and the availability of multi-leaf collimators and electronic portal imaging is limited. Actually only eleven centers have IMRT, eight have projects to install. Only six centers have CT-scans, used mainly for simulation. In 75% of centers conformal radiotherapy have been used in the treatment of CNS-tumors, head and neck cancers, prostate, and non-small cell lung carcinoma. If there are more equipment and human facilities to use conformal radiotherapy, this treatment can be proposed to patients with breast cancer, rectal and gynecological tumors. According 90% of responses, all prostatic cancers need conformal radiotherapy. The analysis of routine use of conformal radiotherapy in France shows an important heterogeneity but it seems that there is an agreement with objectives of this treatment. (authors)

Pretreatment Endorectal Coil Magnetic Resonance Imaging Findings Predict Biochemical Tumor Control in Prostate Cancer Patients Treated With Combination Brachytherapy and External-Beam Radiotherapy

International Nuclear Information System (INIS)

Riaz, Nadeem; Afaq, Asim; Akin, Oguz; Pei Xin; Kollmeier, Marisa A.; Cox, Brett; Hricak, Hedvig; Zelefsky, Michael J.

2012-01-01

Purpose: To investigate the utility of endorectal coil magenetic resonance imaging (eMRI) in predicting biochemical relapse in prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Methods and Materials: Between 2000 and 2008, 279 men with intermediate- or high-risk prostate cancer underwent eMRI of their prostate before receiving brachytherapy and supplemental intensity-modulated radiotherapy. Endorectal coil MRI was performed before treatment and retrospectively reviewed by two radiologists experienced in genitourinary MRI. Image-based variables, including tumor diameter, location, number of sextants involved, and the presence of extracapsular extension (ECE), were incorporated with other established clinical variables to predict biochemical control outcomes. The median follow-up was 49 months (range, 1–13 years). Results: The 5-year biochemical relapse-free survival for the cohort was 92%. Clinical findings predicting recurrence on univariate analysis included Gleason score (hazard ratio [HR] 3.6, p = 0.001), PSA (HR 1.04, p = 0.005), and National Comprehensive Cancer Network risk group (HR 4.1, p = 0.002). Clinical T stage and the use of androgen deprivation therapy were not correlated with biochemical failure. Imaging findings on univariate analysis associated with relapse included ECE on MRI (HR 3.79, p = 0.003), tumor size (HR 2.58, p = 0.04), and T stage (HR 1.71, p = 0.004). On multivariate analysis incorporating both clinical and imaging findings, only ECE on MRI and Gleason score were independent predictors of recurrence. Conclusions: Pretreatment eMRI findings predict for biochemical recurrence in intermediate- and high-risk prostate cancer patients treated with combination brachytherapy and external-beam radiotherapy. Gleason score and the presence of ECE on MRI were the only significant predictors of biochemical relapse in this group of patients.

Quality of life after radiotherapy for prostate cancer; Qualite de vie apres radiotherapie pour un cancer localise de la prostate

Energy Technology Data Exchange (ETDEWEB)

Joly, F. [Service d' oncologie medicale, CLCC Francois-Baclesse, 14 - Caen (France); CHU Cote-de-Nacre, 14 - Caen (France); Degrendel, A.C. [Service de radiotherapie, CLCC Francois-Baclesse, 14 - Caen (France); Guizard, A.V. [Registre general des tumeurs du Calvados, CLCC Francois-Baclesse, 14 - Caen (France)

2010-10-15

The goal of localized prostate cancer radiotherapy is to cure patients. The decision-making must integrate the survival but also the quality of life of patients. Some French validated self-reported questionnaires are available to evaluate quality of life. Whatever the treatments (radical prostatectomy, brachytherapy, external beam radiation, with or without hormono-therapy), even if patients report more sequelae, their long-term quality of life is similar to that of the general population, except for patients treated with hormono-therapy who complain more decline of physical quality of life. In comparison with prostatectomy, patients treated with external beam radiation report less long-lasting urinary symptoms, but more bowel side effects, with no difference in global quality of life. Sexual disorders are initially less important with external beam radiation but increase over time. Brachytherapy shows no sexual function preservation benefit relative to radiation and may be less favourable with more urinary sequelae. The association of hormono-therapy and external beam radiation decreases the quality of life of the patients, with a negative impact on vitality, sexuality and increase urinary disorders. Intensity-modulated radiotherapy (IMRT) seems to better preserve the long-term digestive quality of life in comparison with conformal radiation therapy. Post-prostatectomy could induce more digestive toxicity, such as rectal irritation. The adjunction of hormono-therapy to radiation, the previous medical history of abdominal surgery, the field of radiation and the acute reactions to radiation are the main predictive factors to late toxicity and should be considered in the choice of initial treatment and for the follow-up. (authors)

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

Long-Term Results of Conformal Radiotherapy for Progressive Airway Amyloidosis

Energy Technology Data Exchange (ETDEWEB)

Truong, Minh Tam, E-mail: mitruong@bu.edu [Department of Radiation Oncology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Grillone, Gregory A. [Department of Otolaryngology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Bohrs, Harry K.; Lee, Richard [Department of Radiation Oncology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Sakai, Osamu [Department of Radiology, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States); Berk, John L. [Department of Medicine, Amyloid Treatment and Research Program, Boston University School of Medicine, Boston Medical Center, Boston, MA (United States)

2012-06-01

Purpose: To evaluate the efficacy of conformal external beam radiotherapy (RT) for local control of progressive airway amyloidosis. Methods and Materials: We conducted a retrospective review of patients with biopsy-proven progressive airway amyloidosis treated with conformal RT between 2000 and 2006 at Boston Medical Center. The patients were evaluated for performance status and pulmonary function, with computed tomography and endoscopy after RT compared with the pretreatment studies. Local control was defined as the lack of progression of airway wall thickening on computed tomography imaging and stable endobronchial deposits by endoscopy. Results: A total of 10 symptomatic airway amyloidosis patients (3 laryngeal and 7 tracheobronchial) received RT to a median total dose of 20 Gy in 10 fractions within 2 weeks. At a median follow-up of 6.7 years (range, 1.5-10.3), 8 of the 10 patients had local control. The remaining 2 patients underwent repeat RT 6 and 8.4 months after initial RT, 1 for persistent bronchial obstruction and 1 for progression of subglottic amyloid disease with subsequent disease control. The Eastern Cooperative Oncology Group performance status improved at a median of 18 months after RT compared with the baseline values, from a median score of 2 to a median of 1 (p = .035). Airflow (forced expiratory volume in 1 second) measurements increased compared with the baseline values at each follow-up evaluation, reaching a 10.7% increase (p = .087) at the last testing (median duration, 64.8 months). Acute toxicity was limited to Grade 1-2 esophagitis, occurring in 40% of patients. No late toxicity was observed. Conclusions: RT prevented progressive amyloid deposition in 8 of 10 patients, resulting in a marginally increased forced expiratory volume in 1 second, and improved functional capacity, without late morbidity.

External radiotherapy in a pleural mesothelioma tumor

International Nuclear Information System (INIS)

Fernandez, M.C.; Garcia, J.L.; Gomez, A.; Simon, J.L.; Maillo, M.; Jimenez Torres, M. J.

1994-01-01

Pleural mesothelioma is an uncommon tumor compared with other thoracic malignancies and a 80% of the cases have asbestos exposure. From 1983 to 1992 we have examined patients suffering from malignant pleural mesothelioma treated with external radiotherapy. We treated 11 patients of which 9 were males and 2 were females. The most frequent symptom was the chest pain and all these patients underwent a torascoscopy followed by a pleasured. Of the 11 cases: 10 were malignant epithelial mesothelioma and 1 was a mixed pleural case. Afterwards, they were treated with external radiotherapy between 30 and 55 Gy, with few complications. At the moment, 5 patients are still alive and there is a survival rate of 50% at 24 and 60 months and of 25% at 120 months. We think that external radiotherapy is a good palliative treatment with few complications. (Author) 28 refs

Movement of the cervix in after-loading brachytherapy: implications for designing external-beam radiotherapy boost fields.

Science.gov (United States)

Hombaiah, U; Blake, P; Bidmead, M

2006-05-01

Women with invasive carcinoma of the cervix treated by chemo-radiotherapy and brachytherapy may also receive a pelvic sidewall boost using a midline shield (MLS). The purpose of this study was to assess the usefulness of implanted gold grains in detecting the movement of the cervix caused by the insertion of low-dose-rate brachytherapy applicators, and its implications in designing the MLS. The medical records of 42 women with various stages of cervical carcinoma, who were treated by radical chemo-radiotherapy, were reviewed. All of these women underwent examination under anaesthesia (EUA) and a gold-grain insertion to demarcate the vaginal tumour extent, in the antero-posterior and lateral planes, before starting external-beam radiotherapy. The isocentric orthogonal films (simulator films) of external radiotherapy and brachytherapy were compared to assess the change in position of the gold grains and the consequences for the design of the MLS for parametrial and pelvic sidewall boosts. A significant shift in the position of the gold grains was noted in both the x (lateral) and the y (cranial/caudal) axes. The median shift of the midline, right and left lateral gold grains was 4.5, 5 and 7 mm in the x axis, whereas it was 10, 8 and 9.5 mm in the y axis, respectively. The median shift in the x and y axes was 5.5 and 9 mm, ranging from 1 to 40 mm and 1 to 45 mm, respectively. The gold grains were shifted cranially in 34 (80%) and laterally in 29 (69%) women. Thirty-two women (76.2%) received parametrial boost radiotherapy, of which 25 (59.5%) women had a customised, pear-shaped shield, and the remaining seven (16.7%) had a straight-sided, rectangular MLS. Four women (9.5%) relapsed locally, and three of them had been treated using a customised shield. In two of these four women, there was an absolute under-dosage of the central pelvis at the tip of the intra-uterine tube by 50% of the parametrial boost dose (5.4 Gy/3 fractions/3 days). Insertion of the gold grains

Time of Decline in Sexual Function After External Beam Radiotherapy for Prostate Cancer

International Nuclear Information System (INIS)

Siglin, Joshua; Kubicek, Gregory J.; Leiby, Benjamin; Valicenti, Richard K.

2010-01-01

Purpose: Erectile dysfunction is one of the most concerning toxicities for patients in the treatment of prostate cancer. The inconsistent evaluation of sexual function (SF) and limited follow-up data have necessitated additional study to clarify the rate and timing of erectile dysfunction after external beam radiotherapy (EBRT) for prostate cancer. Methods and Materials: A total of 143 men completed baseline data on SF before treatment and at the subsequent follow-up visits. A total of 1187 validated SF inventories were analyzed from the study participants. Multiple domains of SF (sex drive, erectile function, ejaculatory function, and overall satisfaction) were analyzed for ≤8 years of follow-up. Results: The median follow-up was 4.03 years. The strongest predictor of SF after EBRT was SF before treatment. For all domains of SF, the only statistically significant decrease in function occurred in the first 24 months after EBRT. SF stabilized 2 years after treatment completion, with no statistically significant change in any area of SF >2 years after the end of EBRT. Conclusion: These data suggest that SF does not have a continuous decline after EBRT. Instead, SF decreases maximally within the first 24 months after EBRT, with no significant changes thereafter.

External Auditing on Absorbed Dose Using a Solid Water Phantom for Domestic Radiotherapy Facilities

Energy Technology Data Exchange (ETDEWEB)

Choi, Chang Heon; Kim, Jung In; Park, Jong Min; Park, Yang Kyun; Ye, Sung Joon [Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cho, Kun Woo; Cho, Woon Kap [Radiation Research, Korean Institute of Nuclear Safety, Daejeon (Korea, Republic of); Lim, Chun Il [Korea Food and Drug Administration, Seoul (Korea, Republic of)

2010-11-15

We report the results of an external audit on the absorbed dose of radiotherapy beams independently performed by third parties. For this effort, we developed a method to measure the absorbed dose to water in an easy and convenient setup of solid water phantom. In 2008, 12 radiotherapy centers voluntarily participated in the external auditing program and 47 beams of X-ray and electron were independently calibrated by the third party's American Association of Physicists in Medicine (AAPM) task group (TG)-51 protocol. Even though the AAPM TG-51 protocol recommended the use of water, water as a phantom has a few disadvantages, especially in a busy clinic. Instead, we used solid water phantom due to its reproducibility and convenience in terms of setup and transport. Dose conversion factors between solid water and water were determined for photon and electron beams of various energies by using a scaling method and experimental measurements. Most of the beams (74%) were within {+-}2% of the deviation from the third party's protocol. However, two of 20 X-ray beams and three of 27 electron beams were out of the tolerance ({+-}3%), including two beams with a >10% deviation. X-ray beams of higher than 6 MV had no conversion factors, while a 6 MV absorbed dose to a solid water phantom was 0.4% less than the dose to water. The electron dose conversion factors between the solid water phantom and water were determined: The higher the electron energy, the less is the conversion factor. The total uncertainty of the TG-51 protocol measurement using a solid water phantom was determined to be {+-}1.5%. The developed method was successfully applied for the external auditing program, which could be evolved into a credential program of multi-institutional clinical trials. This dosimetry saved time for measuring doses as well as decreased the uncertainty of measurement possibly resulting from the reference setup in water.

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.

Californium-252 Brachytherapy Combined With External-Beam Radiotherapy for Cervical Cancer: Long-Term Treatment Results

International Nuclear Information System (INIS)

Lei Xin; Qian Chengyuan; Qing Yi; Zhao Kewei; Yang Zhengzhou; Dai Nan; Zhong Zhaoyang; Tang Cheng; Li Zheng; Gu Xianqing; Zhou Qian; Feng Yan; Xiong Yanli; Shan Jinlu; Wang Dong

2011-01-01

Purpose: To observe, by retrospective analysis, the curative effects and complications due to californium-252 ( 252 Cf) neutron intracavitary brachytherapy (ICBT) combined with external-beam radiotherapy (EBRT) in the treatment of cervical cancer. Methods and Materials: From February 1999 to December 2007, 696 patients with cervical cancer (Stages IB to IIIB) were treated with 252 Cf-ICBT in combination of EBRT. Of all, 31 patients were at Stage IB, 104 at IIA, 363 at IIB, 64 at IIIA, and 134 at IIIB. Californium-252 ICBT was delivered at 7–12 Gy per insertion per week, with a total dose of 29–45 Gy to reference point A in three to five insertions. The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction, four times per week. After 16–38 Gy of external irradiation, the center of the whole pelvic field was blocked with a 4-cm-wide lead shield, with a total external irradiation dose of 44–56 Gy. The total treatment course was 5 to 6 weeks. Results: Overall survival rate at 3 and 5 years for all patients was 76.0% and 64.9%, respectively. Disease-free 3- and 5-year survival rates of patients were 71.2% and 58.4%, respectively. Late complications included vaginal contracture and adhesion, radiation proctitis, radiation cystitis, and inflammatory bowel, which accounted for 5.8%, 7.1%, 6.2%, and 4.9%, respectively. Univariate analysis results showed significant correlation of stage, age, histopathologic grade, and lymph node status with overall survival. Cox multiple regression analysis showed that the independent variables were stage, histopathologic grade, tumor size, and lymphatic metastasis in all patients. Conclusion: Results of this series suggest that the combined use of 252 Cf-ICBT with EBRT is an effective method for treatment of cervical cancer.

Quality of life after radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Joly, F.; Degrendel, A.C.; Guizard, A.V.

2010-01-01

The goal of localized prostate cancer radiotherapy is to cure patients. The decision-making must integrate the survival but also the quality of life of patients. Some French validated self-reported questionnaires are available to evaluate quality of life. Whatever the treatments (radical prostatectomy, brachytherapy, external beam radiation, with or without hormono-therapy), even if patients report more sequelae, their long-term quality of life is similar to that of the general population, except for patients treated with hormono-therapy who complain more decline of physical quality of life. In comparison with prostatectomy, patients treated with external beam radiation report less long-lasting urinary symptoms, but more bowel side effects, with no difference in global quality of life. Sexual disorders are initially less important with external beam radiation but increase over time. Brachytherapy shows no sexual function preservation benefit relative to radiation and may be less favourable with more urinary sequelae. The association of hormono-therapy and external beam radiation decreases the quality of life of the patients, with a negative impact on vitality, sexuality and increase urinary disorders. Intensity-modulated radiotherapy (IMRT) seems to better preserve the long-term digestive quality of life in comparison with conformal radiation therapy. Post-prostatectomy could induce more digestive toxicity, such as rectal irritation. The adjunction of hormono-therapy to radiation, the previous medical history of abdominal surgery, the field of radiation and the acute reactions to radiation are the main predictive factors to late toxicity and should be considered in the choice of initial treatment and for the follow-up. (authors)

Biological-effective versus conventional dose volume histograms correlated with late genitourinary and gastrointestinal toxicity after external beam radiotherapy for prostate cancer: a matched pair analysis

Directory of Open Access Journals (Sweden)

Roeske John C

2003-05-01

Full Text Available Abstract Background To determine whether the dose-volume histograms (DVH's for the rectum and bladder constructed using biological-effective dose (BED-DVH's better correlate with late gastrointestinal (GI and genitourinary (GU toxicity after treatment with external beam radiotherapy for prostate cancer than conventional DVH's (C-DVH's. Methods The charts of 190 patients treated with external beam radiotherapy with a minimum follow-up of 2 years were reviewed. Six patients (3.2% were found to have RTOG grade 3 GI toxicity, and similarly 6 patients (3.2% were found to have RTOG grade 3 GU toxicity. Average late C-DVH's and BED-DVH's of the bladder and rectum were computed for these patients as well as for matched-pair control patients. For each matched pair the following measures of normalized difference in the DVH's were computed: (a δAUC = (Area Under Curve [AUC] in grade 3 patient – AUC in grade 0 patient/(AUC in grade 0 patient and (b δV60 = (Percent volume receiving = 60 Gy [V60] in grade 3 patient – V60 in grade 0 patient/(V60 in grade 0 patient. Results As expected, the grade 3 curve is to the right of and above the grade 0 curve for all four sets of average DVH's – suggesting that both the C-DVH and the BED-DVH can be used for predicting late toxicity. δAUC was higher for the BED-DVH's than for the C-DVH's – 0.27 vs 0.23 (p = 0.036 for the rectum and 0.24 vs 0.20 (p = 0.065 for the bladder. δV60 was also higher for the BED-DVH's than for the C-DVH's – 2.73 vs 1.49 for the rectum (p = 0.021 and 1.64 vs 0.71 (p = 0.021 for the bladder. Conclusions When considering well-established dosimetric endpoints used in evaluating treatment plans, BED-DVH's for the rectum and bladder correlate better with late toxicity than C-DVH's and should be considered when attempting to minimize late GI and GU toxicity after external beam radiotherapy for prostate cancer.

Conformity Index and Homogeneity Index of the Postoperative Whole Breast Radiotherapy.

Science.gov (United States)

Petrova, Deva; Smickovska, Snezana; Lazarevska, Emilija

2017-10-15

The treatment of breast cancer involves a multidisciplinary approach in which radiotherapy plays a key role. The conformity index and the homogeneity index are two analysis tools of a treatment plan using conformal radiotherapy. The purpose of this article is an analysis of these two parameters in the assessment of the treatment plans in 58 patients undergoing postoperative radiotherapy of the whole breast. All 58 patients participating in the study had a conservatively treated early-stage breast cancer. The treatment was performed using a standard regimen of fractionation in 25 fractions up to a total dose of 50 Gy. Dose-volume histograms were generated for both plans with and without segmental fields. Pair samples t-test was used. The technique with segmental fields allowed us more homogeneity distribution when compared to standard two tangential field techniques. The HI values were 1.08 ± 0.01 and 1.09 ± 0.01 for segment and technique with two tangential fields (p conformity and the homogeneity index are important tools in the analysis of the treatment plans during radiation therapy in patients with early-stage breast cancer. Adding segment fields in the administration of radiotherapy in patients with conservatively treated breast cancer can lead to improved dosage homogeneity and conformity.

Polyethylene glycol hydrogel rectal spacer implantation in patients with prostate cancer undergoing combination high-dose-rate brachytherapy and external beam radiotherapy.

Science.gov (United States)

Yeh, Jekwon; Lehrich, Brandon; Tran, Carolyn; Mesa, Albert; Baghdassarian, Ruben; Yoshida, Jeffrey; Torrey, Robert; Gazzaniga, Michael; Weinberg, Alan; Chalfin, Stuart; Ravera, John; Tokita, Kenneth

2016-01-01

To present rectal toxicity rates in patients administered a polyethylene glycol (PEG) hydrogel rectal spacer in conjunction with combination high-dose-rate brachytherapy and external beam radiotherapy. Between February 2010 and April 2015, 326 prostate carcinoma patients underwent combination high-dose-rate brachytherapy of 16 Gy (average dose 15.5 Gy; standard deviation [SD] = 1.6 Gy) and external beam radiotherapy of 59.4 Gy (average dose 60.2 Gy; SD = 2.9 Gy). In conjunction with the radiation therapy regimen, each patient was injected with 10 mL of a PEG hydrogel in the anterior perirectal fat space. The injectable spacer (rectal spacer) creates a gap between the prostate and the rectum. The rectum is displaced from the radiation field, and rectal dose is substantially reduced. The goal is a reduction in rectal radiation toxicity. Clinical efficacy was determined by measuring acute and chronic rectal toxicity using the National Cancer Center Institute Common Terminology Criteria for Adverse Events v4.0 grading scheme. Median followup was 16 months. The mean anterior-posterior separation achieved was 1.6 cm (SD = 0.4 cm). Rates of acute Grade 1 and 2 rectal toxicity were 37.4% and 2.8%, respectively. There were no acute Grade 3/4 toxicities. Rates of late Grade 1, 2, and 3 rectal toxicity were 12.7%, 1.4%, and 0.7%, respectively. There were no late Grade 4 toxicities. PEG rectal spacer implantation is safe and well tolerated. Acute and chronic rectal toxicities are low despite aggressive dose escalation. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

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

External quality audit programmes for radiotherapy dosimetry and equipment

International Nuclear Information System (INIS)

Thwaites, D.I.

1997-01-01

It is widely accepted that individual radiotherapy centres should have in place a comprehensive quality assurance programme on all the necessary steps for the delivery of safe accurate treatment. As regards the performance of radiotherapy equipment and dosimetry, the most widely used process of external checking has been dosimetry intercomparison, comparing independently measured doses to locally stated doses in a variety of conditions. These have been at a number of different levels: from basic beam calibration; up to and including exercises employing anatomic or pseudo-anatomic phantoms and incorporating tests of treatment planning equipment and procedures. Some of these have been one-off exercises, whilst others are continuing, or have given rise to on-going quality audit programmes on a national (or wider) basis. A number of these have evolved, or are evolving, into audits which include external checking of the achievement of standards in performance of treatment equipment, as well as in the dosimetry in each institution involved. The principles and methodologies of the various types of external checking programmes for treatment equipment and dosimetry are reviewed, covering the experimental approaches and the tolerances applied. What is included in a given programme will, of necessity, depend on the resources available and the purpose of the exercise. Methods and tolerances must be matched to endpoint. Tolerance levels must take into account the experimental uncertainties of the measurement methods employed. Finally, external audit can only be used to complement, and in conjunction with, institutional quality assurance programmes and not as a substitute for them

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

[Technique of complex mammary irradiation: Mono-isocentric 3D conformational radiotherapy and helical tomotherapy].

Science.gov (United States)

Vandendorpe, B; Guilbert, P; Champagne, C; Antoni, T; Nguyen, T D; Gaillot-Petit, N; Servagi Vernat, S

2017-12-01

To evaluate the dosimetric contribution of helical tomotherapy for breast cancers compared with conformal radiotherapy in mono-isocentric technique. For 23 patients, the dosimetric results in mono-isocentric 3D conformational radiotherapy did not satisfy the constraints either of target volumes nor organs at risk. A prospective dosimetric comparison between mono-isocentric 3D conformational radiotherapy and helical tomotherapy was therefore carried out. The use of helical tomotherapy showed a benefit in these 23 patients, with either an improvement in the conformity index or homogeneity, but with an increase in low doses. Of the 23 patients, two had pectus excavatum, five had past thoracic irradiation and two required bilateral irradiation. The other 14 patients had a combination of morphology and/or indication of lymph node irradiation. For these patients, helical tomotherapy was therefore preferred to mono-isocentric 3D conformational radiotherapy. Tomotherapy appears to provide better homogeneity and tumour coverage. This technique of irradiation may be justified in the case of morphological situations such as pectus exavatum and in complex clinical situations. In other cases, conformal radiotherapy in mono-isocentric technique remains to be favoured. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Conkiss: Conformal Kidneys Sparing 3D Noncoplanar Radiotherapy Treatment for Pancreatic Cancer As an Alternative to IMRT

International Nuclear Information System (INIS)

Sebestyen, Zsolt; Kovacs, Peter; Gulyban, Akos; Farkas, Robert; Bellyei, Szabolcs; Liposits, Gabor; Szigeti, Andras; Esik, Olga; Derczy, Katalin; Mangel, Laszlo

2011-01-01

When treating pancreatic cancer using standard (ST) 3D conformal radiotherapy (3D-CRT) beam arrangements, the kidneys often receive a higher dose than their probable tolerance limit. Our aim was to elaborate a new planning method that-similarly to IMRT-effectively spares the kidneys without compromising the target coverage. Conformal kidneys sparing (CONKISS) 5-field, noncoplanar plans were compared with ST plans for 23 consecutive patients retrospectively. Optimal beam arrangements were used consisting of a left- and right-wedged beam-pair and an anteroposterior beam inclined in the caudal direction. The wedge direction determination (WEDDE) algorithm was developed to adjust the adequate direction of wedges. The aimed organs at risk (OARs) mean dose limits were: kidney <12 Gy, liver <25 Gy, small bowels <30 Gy, and spinal cord maximum <45 Gy. Conformity and homogeneity indexes with z-test were used to evaluate and compare the different planning approaches. The mean dose to the kidneys decreased significantly (p < 0.05): left kidney 7.7 vs. 10.7 Gy, right kidney 9.1 vs. 11.7 Gy. Meanwhile the mean dose to the liver increased significantly (18.1 vs. 15.0 Gy). The changes in the conformity, homogeneity, and in the doses to other OARs were not significant. The CONKISS method balances the load among the OARs and significantly reduces the dose to the kidneys, without any significant change in the conformity and homogeneity. Using 3D-CRT the CONKISS method can be a smart alternative to IMRT to enhance the possibility of dose escalation.

Risk-adapted targeted intraoperative radiotherapy versus whole-breast radiotherapy for breast cancer

DEFF Research Database (Denmark)

Vaidya, Jayant S; Wenz, Frederik; Bulsara, Max

2014-01-01

The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intraoperative radiotherapy (TARGIT) versus fractionated external beam radiotherapy (EBRT) for breast cancer. We report 5-year results for local recurrence and the first analysis of overall survival....

The magic cube and the pixel ionization chamber: detectors for monitor and dosimetry of radiotherapy beams

International Nuclear Information System (INIS)

Amerio, S.; Boriano, A.; Bourhaleb, F.; Cirio, R.; Donetti, M.; Garelli, E.; Giordanengo, S.; Madon, E.; Marchetto, F.; Nastasi, U.; Peroni, C.; Sanz Freire, C.J.; Sardo, A.; Trevisiol, E.

2003-01-01

Tumor therapy takes advantage of the energy deposition of radiation to concentrate high doses in the target while sparing healthy tissue. Elective pathologies for highly conformal radiotherapies such as photon Intensity Modulated Radiotherapy (IMRT) and radiotherapy with hadrons are head and neck, eye, prostate and in general all tumors that are either deep or located close to critical organs. In the world there are several centers that are using such techniques and a common problem that is being experienced is the verification of treatment plans and monitoring of the beam. We have designed and built two detectors that allow 2D and 3D measurements of dose and fluence of such beams. The detectors allow measurements on big surfaces, up to 25*25 cm 2 . The active media are parallel plate, strip and pixel segmented ionization chambers with front-end Very Large Scale Integration (VLSI) readout and PC based data acquistion. The description of dosimeter, chamber and electronics will be given with results from beam tests and therapy plan verification

The value of 18F-FDG PET in three-dimensional conformal radiotherapy of cancer

International Nuclear Information System (INIS)

Lv Huiqing; Zhang Zhongmin; Lv Zhonghong

2006-01-01

Three-dimensional conformal radiotherapy (3D-CRT) is based on an extensive use of modern medical imaging techniques. Delineation of the gross tumor volume and organs at risk constitutes one of the most important phases of conformal radiotherapy procedures. 18 F-fluorodeoxyglucose ( 18 F-FDG) PET possesses greater sensitivity and accuracy in detecting diseased lymph nodes, is an important staging examination for patients considered for radiation treatment with curative intent. 18 F-FDG PET has an important role in delineation of gross tumor volume for patients treated with three-dimensional conformal radiotherapy. (authors)

Acute and late side-effects of conventional and conformal pelvic radiotherapy for cervical and endometrial cancer

International Nuclear Information System (INIS)

Izmajlowicz, B.; Komafel, J.

2010-01-01

Aim of the study. The purpose of this prospective study was to analyze and compare acute and late side-effects observed in patients with cervical and endometrial cancer treated with conventional 2-dimensional (2D) and conformal 3-dimensional (3D) pelvic radiotherapy. Patients and method. 50 patients treated with conventional pelvic radiotherapy and 50 patients treated with conformal pelvic radiotherapy at the Clinical Department of Gynecological Radiotherapy of the Lower Silesian Oncology Center between November 2004 and October 2005 were entered into a prospective study. We assessed Radiotherapy side-effects according to EORTCIRTOG, performance status according to the WHO, Body Mass Index and hematologic parameters during radiotherapy and one year after treatment. Results. Performance status acc. to the WHO was significantly better in the conformal arm. Anemia and nausea were more frequent in the conventional arm. In both the study groups acute gastrointestinal and genitourinary morbidity was more frequent than late morbidity and performance status was better after than before radiotherapy. Mean BMI was lower after radiotherapy than before treatment. Conclusions. Conformal pelvic radiotherapy in patients with cervical and endometrial cancer is less toxic than conventional pelvic radiotherapy which is also confirmed by the performance status. (authors)

Nasopharyngeal carcinoma treated by radical radiotherapy alone: Ten-year experience of a single institution

International Nuclear Information System (INIS)

Yi Junlin; Gao Li; Huang Xiaodong; Li Suyan; Luo Jinwei; Cai Weiming; Xiao Jianping; Xu Guozhen

2006-01-01

Purpose: To report on our experience in the treatment of nasopharyngeal carcinoma (NPC) by radical radiotherapy alone in our institution during the last decade. Methods and Materials: From January 1990 to May 1999, 905 NPC patients were treated and were studied retrospectively. Radical radiotherapy was given to this cohort by conventional technique in a routine dose of 70-72 Gy to the primary tumor and metastatic lymph nodes. In case of residual primary lesion, a boost dose of 8-24 Gy was delivered by either 192 Ir afterloading brachytherapy, fractionated stereotactic radiotherapy, conformal radiotherapy, or small external-beam fields. Results: The 5-year and 10-year local-regional control, overall survival, and disease-free survival rates were 81.7% and 76.7%, 76.1% and 66.5%, 58.4% and 52.1%, respectively. In case of residual primary lesions after a dose of 70-72 Gy of conventional external-beam radiotherapy (EBRT), an additional boost was able to achieve a local control of 80.8%, similar to that obtained with primary lesions that completely disappeared at 70-72 Gy (82.6%, p = 0.892). Conclusions: The treatment results of radical EBRT followed by a boost dose to the residual primary tumor for nasopharyngeal carcinoma in our institution are promising

Analysis of the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy

Directory of Open Access Journals (Sweden)

Song-Lin Wang

2017-04-01

Full Text Available Objective: To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy. Methods: A total of 84 patients who were admitted in our hospital after modified radical mastectomy were included in the study and divided into the conventional radiotherapy group (n=42 and the three-dimensional conformal radiotherapy group (n=42 according to different radiotherapy methods. The patients in the conventional radiotherapy group were given conventional radiotherapy of chest wall and clavicular field, while the patients in the three-dimensional conformal radiotherapy group were given three-dimensional conformal radiotherapy. The serum tumor markers and peripheral blood T lymphocyte subsets 6-8 weeks after treatment in the two groups were detected. The clinical efficacy, and toxic and side effects in the two groups were evaluated. Results: The serum CA15-3, CA125, CEA, and CK19 levels after treatment in the two groups were significantly reduced when compared with before treatment, CD3 +,CD4 +, and CD4 +/CD8 + were significantly elevated, while CD8 + was significantly reduced when compared with before treatment, but the comparison of the above indicators between the two groups was not statistically significant. The occurrence rate of radioactive skin damage and pneumonia after treatment in the conventional radiotherapy group was significantly higher than that in the three-dimensional conformal radiotherapy group. Conclusions: The two kinds of radiotherapy schemes have an equal efficacy, but the toxic and side effects of three-dimensional conformal radiotherapy are significantly lower than those by the conventional radiotherapy, with a certain advantage.

Knowledge-based prediction of three-dimensional dose distributions for external beam radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Shiraishi, Satomi; Moore, Kevin L., E-mail: kevinmoore@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California 92093 (United States)

2016-01-15

Purpose: To demonstrate knowledge-based 3D dose prediction for external beam radiotherapy. Methods: Using previously treated plans as training data, an artificial neural network (ANN) was trained to predict a dose matrix based on patient-specific geometric and planning parameters, such as the closest distance (r) to planning target volume (PTV) and organ-at-risks (OARs). Twenty-three prostate and 43 stereotactic radiosurgery/radiotherapy (SRS/SRT) cases with at least one nearby OAR were studied. All were planned with volumetric-modulated arc therapy to prescription doses of 81 Gy for prostate and 12–30 Gy for SRS. Using these clinically approved plans, ANNs were trained to predict dose matrix and the predictive accuracy was evaluated using the dose difference between the clinical plan and prediction, δD = D{sub clin} − D{sub pred}. The mean (〈δD{sub r}〉), standard deviation (σ{sub δD{sub r}}), and their interquartile range (IQR) for the training plans were evaluated at a 2–3 mm interval from the PTV boundary (r{sub PTV}) to assess prediction bias and precision. Initially, unfiltered models which were trained using all plans in the cohorts were created for each treatment site. The models predict approximately the average quality of OAR sparing. Emphasizing a subset of plans that exhibited superior to the average OAR sparing during training, refined models were created to predict high-quality rectum sparing for prostate and brainstem sparing for SRS. Using the refined model, potentially suboptimal plans were identified where the model predicted further sparing of the OARs was achievable. Replans were performed to test if the OAR sparing could be improved as predicted by the model. Results: The refined models demonstrated highly accurate dose distribution prediction. For prostate cases, the average prediction bias for all voxels irrespective of organ delineation ranged from −1% to 0% with maximum IQR of 3% over r{sub PTV} ∈ [ − 6, 30] mm. The

A computer-controlled high resolution micro-multi-leaf collimator for stereotactic conformal radio-therapy

International Nuclear Information System (INIS)

Schlegel, Wolfgang; Pastyr, Otto; Kubesch, Rudolf; Diemer, Torsten; Kuester, Gunnilla; Rhein, Bernhard; Hoever, Karl-Heinz

1997-01-01

Purpose/Objective In stereotactic conformal radiotherapy of irregularly shaped lesions, either multi-isocentric convergent beam treatment techniques with circular collimators or irregular shaped beams are being used. While the treatment technique with multiple isocenters has the disadvantage of producing inhomogeneous dose distributions, the use of irregular shaped fields is not yet satisfying from a technical point of view: Cerrobend blocking or the use of static micro MLCs need a long preparation time and only allow static treatment techniques, MLC collimators which are commercially available in connection with modern LINACs have leaf-thickness of at least 1 cm which is too coarse for stereotactic radiotherapy of lesions in the brain and head and neck area. For this reason, we developed a computer controlled micro-MLC with technical specifications matched to the needs of stereotactic radiotherapy and radiosurgery. Materials and Methods The mechanical specifications of the computer controlled micro-MLC were derived from our experience with stereotactic treatment techniques, from the requirement that the MLC has to be attachable as an external device to the accessory holders of standard LINACs, including cost considerations, dosimetric measurements as well as Monte Carlo calculations. The Micro-MLC is controlled by an electronic equipment consisting of a standard PC under Windows 95, an interface board, 14 Micro-controller boards, a verification system and 80 driving units equipped with DC motors and potentiometers. The control program has calibrating, operating, visualizing and test options. Irregular field data are transferred from the treatment planning computer to the control PC and distributed to the micro-controllers, which in parallel are driving three leaves each. Beside the special control unit, we are currently investigating whether the electronics of commercially available integrated large field MLCs can also be used for operating the Micro-MLC. Results

Geometric accuracy of field alignment in fractionated stereotactic conformal radiotherapy of brain tumors

International Nuclear Information System (INIS)

Kortmann, Rolf D.; Becker, Gerd; Perelmouter, Jury; Buchgeister, Markus; Meisner, Christoph; Bamberg, Michael

1999-01-01

Purpose: To assess the accuracy of field alignment in patients undergoing three-dimensional (3D) conformal radiotherapy of brain tumors, and to evaluate the impact on the definition of planning target volume and control procedures. Methods and Materials: Geometric accuracy was analyzed in 20 patients undergoing fractionated stereotactic conformal radiotherapy for brain tumors. Rigid head fixation was achieved by using cast material. Transfer of stereotactic coordinates was performed by an external positioning device. The accuracy during treatment planning was quantitatively assessed by using repeated computed tomography (CT) examinations in treatment position (reproducibility of isocenter). Linear discrepancies were measured between treatment plan and CT examination. In addition, for each patient, a series of 20 verifications were taken in orthogonal projections. Linear discrepancies were measured between first and all subsequent verifications (accuracy during treatment delivery). Results: For the total group of patients, the distribution of deviations during treatment setup showed mean values between -0.3-1.2 mm, with standard deviations (SD) of 1.3-2.0 mm. During treatment delivery, the distribution of deviations revealed mean values between 0.7-0.8 mm, with SDs of 0.5-0.6 mm, respectively. For all patients, deviations for the transition to the treatment machine were similar to deviations during subsequent treatment delivery, with 95% of all absolute deviations between less than 2.8 and 4.6 mm. Conclusion: Random fluctuations of field displacements during treatment planning and delivery prevail. Therefore, our quantitative data should be considered when prescribing the safety margins of the planning target volume. Repeated CT examination are useful to detect operator errors and large random or systematic deviations before start of treatment. Control procedures during treatment delivery appear to be of limited importance. In addition, our findings should help to

Guidelines for primary radiotherapy of patients with prostate cancer

International Nuclear Information System (INIS)

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

Evaluation of the response of concurrent high dose rate intracavitary brachytherapy with external beam radiotherapy in management of early stage carcinoma cervix.

Science.gov (United States)

Patidar, Arvind Kumar; Kumar, H S; Walke, Rahul V; Hirapara, Pushpendra H; Jakhar, Shankar Lal; Bardia, M R

2012-10-01

To evaluate local disease control and early complications of concomitant brachytherapy with external beam-radiotherapy in early stage carcinoma cervix. Fifty patients of early stage carcinoma cervix (FIGO-IB/IIA) were randomly divided into study group concomitant external beam irradiation (EBRT) and HDR-ICBT (intra-cavitary brachytherapy, xrt = 50 Gy/25 Fr, HDR 5.2 Gy*5 Fr) and the control group EBRT followed by HDR-ICBT (xrt = 50 Gy/25 Fr, HDR 7.5 Gy*3 Fr). Acute reactions and local disease response were compared between treatment and at 6-month follow up. Median overall treatment times were 38 and 61 days in the study and the control groups, respectively. Acute skin reactions and diarrhea were more in the study but manageable. At the completion of the study, there were 80 and 68 % complete responses, 16 and 20 % partial responses, 0 and 8 % stable diseases in the study group and the control group, respectively. Response was better in the study group but statistically insignificant. Larger number of patients and longer follow up are required to arrive at concrete conclusion.

External Beam Radiotherapy for Focal Lymphoepithelioma-Like Carcinoma in the Urinary Bladder: A Case Report and Literature Review

Directory of Open Access Journals (Sweden)

Nobuhiro Kushida

2015-01-01

Full Text Available Lymphoepithelioma is a malignant epithelial tumor in the nasopharynx characterized by prominent lymphoid infiltration. Carcinomas that resemble lymphoepitheliomas have been called lymphoepithelioma-like carcinomas and have been reported in other organs. A tumor in the bladder is categorized by the percentage of the total area occupied by the lymphoepithelioma-like carcinoma pattern, with the prognosis dependent on the percentage. We present an 81-year-old man with stage 3 chronic obstructive pulmonary disease and a history of aortic aneurysm repair. The computed tomography scans indicated thickening and irregularity of the bladder wall, with left external iliac lymph node metastasis. His diagnosis was bladder cancer, and the clinical stage was evaluated as T3N1M0. Transurethral resection of the bladder tumor was performed, and the pathological specimen showed that the tumor was composed of undifferentiated malignant cells with sheets and nests arranged in a syncytial pattern, as well as an urothelial carcinoma lesion. A prominent lymphoid reaction accompanied the tumor. The pathological diagnosis was focal-type lymphoepithelioma-like carcinoma containing a component of urothelial carcinoma G3>G2. His general condition was such that he could not tolerate radical cystectomy or systemic chemotherapy. External beam radiotherapy (total 60 Gy was given to the bladder, including the lymph node metastatic lesion. No cancer recurrence was detected by regular follow-up computed tomography and cystoscopy. He eventually died of other causes 48 months later. Although treatment for focal lymphoepithelioma-like carcinoma generally requires multifocal therapies, in the present case, the bladder became tumor free. We also summarize previously reported lymphoepithelioma-like carcinoma cases treated with radiotherapy.

External beam radiotherapy alone or combined with high-dose-rate intracavitary irradiation in the treatment of cancer of the esophagus

International Nuclear Information System (INIS)

Hishikawa, Y.; Taniguchi, M.; Kamikonya, N.; Tanaka, S.; Miura, T.

1988-01-01

Autopsy findings of 35 patients, treated with radiotherapy for an esophageal carcinoma, were reviewed. A residual tumor was seen at autopsy in 7 of 16 patients treated with high-dose-rate intracavitary irradiation following external irradiation, in 13 of 14 patients treated with external irradiation of 50 Gy or more, and in all 5 patients treated with external irradiation of less than 50 Gy. Incidence on lymph node metastasis, at autopsy, did not diifer between the combined radiotherapy group and the external irradiation groups. However, it correlated with disease stage. It was observed in 11 of 17 patients with Stage 1 and Stage 2 disease, compared to 17 of 18 patients with Stage 3 and Stage 4 disease. Distant organ metastasis, at autopsy, also did not differ between the combined radiotherapy group and the external irradiation groups, and was also correlated with disease stage. It was found in 8 of 17 patients with Stage 1 and Stage 2 disease, compared to all 18 patients with Stage 3 and Stage 4 disease. Mean survival was different between the patients treated by high-dose-rate intracavitary irradiation following external irradiation and those treated by external irradiation alone; 11.3 months in the 16 patients treated with combined therapy, as compared to 6.9 months in the 14 patients who received external irradiation of 50 Gy or more, and 3.6 months in the 5 patients who received external irradiation of less than 50 Gy. 6 refs.; 5 tabs

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

Randomized Control Trial: Evaluating Aluminum-Based Antiperspirant Use, Axilla Skin Toxicity, and Reported Quality of Life in Women Receiving External Beam Radiotherapy for Treatment of Stage 0, I, and II Breast Cancer

Energy Technology Data Exchange (ETDEWEB)

Watson, Linda C., E-mail: Linda.watson@albertahealthservices.ca [Department of Interdisciplinary Practice, Community Oncology, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Gies, Donna [Department of Radiation Oncology Nursing, Tom Baker Cancer Centre, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Thompson, Emmanuel [Department of Mathematics and Statistics, University of Calgary Faculty of Science, Calgary, AB (Canada); Thomas, Bejoy [Department of Psychosocial Resources, Tom Baker Cancer Centre, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Department of Psychosocial Oncology, University of Calgary Faculty of Medicine, Calgary, AB (Canada)

2012-05-01

Purpose: Standard skin care instructions regarding the use of antiperspirants during radiotherapy to the breast varies across North America. Women have articulated that when instructed to not use antiperspirant, the potential for body odor is distressing. Historical practices and individual opinions have often guided practice in this field. The present study had 2 purposes. To evaluate whether the use of aluminum-based antiperspirant while receiving external beam radiotherapy for stage 0, I, or II breast cancer will increase axilla skin toxicity and to evaluate whether the use of antiperspirant during external beam radiotherapy improves quality of life. Methods: A total of 198 participants were randomized to either the experimental group (antiperspirant) or control group (standard care-wash only). The skin reactions in both groups were measured weekly and 2 weeks after treatment using the National Cancer Institute Common Toxicity Criteria Adverse Events, version 3, toxicity grading criteria. Both groups completed the Functional Assessment for Chronic Illness Therapy's questionnaire for the breast population quality of life assessment tool, with additional questions evaluating the effect of underarm antiperspirant use on quality of life before treatment, immediately after treatment, and 2 weeks after treatment during the study. Results: The skin reaction data were analyzed using the generalized estimating equation. No statistically significant difference was seen in the skin reaction between the 2 groups over time. The quality of life data also revealed no statistically significant difference between the 2 groups over time. Conclusions: Data analysis indicates that using antiperspirant routinely during external beam radiotherapy for Stage 0, I, or II breast cancer does not affect the intensity of the skin reaction or the self-reported quality of life. This evidence supports that in this particular population, there is no purpose to restrict these women from

Randomized Control Trial: Evaluating Aluminum-Based Antiperspirant Use, Axilla Skin Toxicity, and Reported Quality of Life in Women Receiving External Beam Radiotherapy for Treatment of Stage 0, I, and II Breast Cancer

International Nuclear Information System (INIS)

Watson, Linda C.; Gies, Donna; Thompson, Emmanuel; Thomas, Bejoy

2012-01-01

Purpose: Standard skin care instructions regarding the use of antiperspirants during radiotherapy to the breast varies across North America. Women have articulated that when instructed to not use antiperspirant, the potential for body odor is distressing. Historical practices and individual opinions have often guided practice in this field. The present study had 2 purposes. To evaluate whether the use of aluminum-based antiperspirant while receiving external beam radiotherapy for stage 0, I, or II breast cancer will increase axilla skin toxicity and to evaluate whether the use of antiperspirant during external beam radiotherapy improves quality of life. Methods: A total of 198 participants were randomized to either the experimental group (antiperspirant) or control group (standard care-wash only). The skin reactions in both groups were measured weekly and 2 weeks after treatment using the National Cancer Institute Common Toxicity Criteria Adverse Events, version 3, toxicity grading criteria. Both groups completed the Functional Assessment for Chronic Illness Therapy’s questionnaire for the breast population quality of life assessment tool, with additional questions evaluating the effect of underarm antiperspirant use on quality of life before treatment, immediately after treatment, and 2 weeks after treatment during the study. Results: The skin reaction data were analyzed using the generalized estimating equation. No statistically significant difference was seen in the skin reaction between the 2 groups over time. The quality of life data also revealed no statistically significant difference between the 2 groups over time. Conclusions: Data analysis indicates that using antiperspirant routinely during external beam radiotherapy for Stage 0, I, or II breast cancer does not affect the intensity of the skin reaction or the self-reported quality of life. This evidence supports that in this particular population, there is no purpose to restrict these women from using

Hyperfractionated conformal radiotherapy in locally advanced prostate cancer: results of a dose escalation study

International Nuclear Information System (INIS)

Forman, Jeffrey D.; Duclos, Marie; Shamsa, Falah; Porter, Arthur T.; Orton, Colin

1996-01-01

Purpose: This study was initiated to assess the incidence of chronic complications and histologic and biochemical control following hyperfractionated conformal radiotherapy in patients with locally advanced prostate cancer. Methods and Materials: Between October 1991 and October 1994, 49 patients with locally advanced prostate cancer were entered on the first two dose levels of a prospective dose-escalation study using hyperfractionated three dimensional conformal radiotherapy. The first 25 patients received a minimum tumor dose of 78 Gy to the prostate and seminal vesicles in 6 weeks at 1.3 Gy, b.i.d. No increase in chronic toxicity compared with conventional radiotherapy was noted; therefore, an additional 24 patients were treated to a minimum tumor dose of 82.8 Gy to the prostate and seminal vesicles in 7 weeks at 1.15 Gy, b.i.d. Toxicity was scored according to the Radiation Therapy Oncology Group morbidity grading scale. Efficacy was assessed through scheduled postradiation prostate specific antigen values and ultrasound-guided biopsies. The median follow-up for the entire group was 20 months. Results: The hyperfractionated external radiation was well tolerated with minimal acute morbidity. At 30 months, the actuarial probability of Grade 2 gastrointestinal toxicity was 17%. At 30 months, the actuarial probability of Grade 2 genitourinary toxicity was 16%. There was no statistically significant difference between the two dose levels. No Grade 3 or 4 gastrointestinal or genitourinary toxicity was noted. At 12 months, 84% of patients had a prostate specific antigen ≤ 4; and 53%; ≤ 1 ng/ml. At 12 months, 71% of patients had post radiation biopsies that were either negative (55%) or showed a marked therapeutic effect (16%). Conclusion: The use of hyperfractionated conformal radiotherapy facilitated dose escalation with no increase in chronic toxicity compared to standard doses. The initial tumor response based on prostate specific antigen measurements and

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)

Study on the photoneutrons produced in 15 MV medical linear accelerators : Comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Yang, Oh Nam [Gangneung Asan Hospital, Gangneung (Korea, Republic of); Yang, Oh Nam; Lim, Cheong Hwan [Hanseo Univ., Seosan (Korea, Republic of)

2012-12-15

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photoneutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photon beams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose.

Study on the photoneutrons produced in 15 MV medical linear accelerators : Comparison of three dimensional conformal radiotherapy and intensity modulated radiotherapy

International Nuclear Information System (INIS)

Yang, Oh Nam; Yang, Oh Nam; Lim, Cheong Hwan

2012-01-01

Intensity-modulated radiotherapy(IMRT) have the ability to provide better dose conformity and sparing of critical normal tissues than three-dimensional radiotherapy(3DCRT). Especially, with the benefit of health insurance in 2011, its use now increasingly in many modern radiotherapy departments. Also the use of linear accelerator with high-energy photon beams over 10 MV is increasing. As is well known, these linacs have the capacity to produce photoneutrons due to photonuclear reactions in materials with a large atomic number such as the target, flattening filters, collimators, and multi-leaf collimators(MLC). MLC-based IMRT treatments increase the monitor units and the probability of production of photoneutrons from photon-induced nuclear reactions. The purpose of this study is to quantitatively evaluate the dose of photoneutrons produced from 3DCRT and IMRT technique for Rando phantom in cervical cancer. We performed the treatment plans with 3DCRT and IMRT technique using Rando phantom for treatment of cervical cancer. An Rando phantom placed on the couch in the supine position was irradiated using 15 MV photon beams. Optically stimulated luminescence dosimeters(OSLD) were attached to 4 different locations (abdomen, chest, head and neck, eyes) and from center of field size and measured 5 times each of locations. Measured neutron dose from IMRT technique increased by 9.0, 8.6, 8.8, and 14 times than 3DCRT technique for abdomen, chest, head and neck, and eyes, respectively. When using IMRT with 15 MV photon beams, the photoneutrons contributed a significant portion on out-of-field. It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, It is difficult to prevent high energy photon beams to produce the photoneutrons due to physical properties, if necessary, it is need to provide the additional safe shielding on a linear accelerator and should therefore reduce the out-of-field dose

Doses to organs at cerebral risks: optimization by robotized stereotaxic radiotherapy and automatic segmentation atlas versus three dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Bondiau, P.Y.; Thariat, J.; Benezery, K.; Herault, J.; Dalmasso, C.; Marcie, S.; Malandain, G.

2007-01-01

The stereotaxic radiotherapy robotized by 'Cyberknife fourth generation' allows a dosimetric optimization with a high conformity index on the tumor and radiation doses limited on organs at risk. A cerebral automatic anatomic segmentation atlas of organs at risk are used in routine in three dimensions. This study evaluated the superiority of the stereotaxic radiotherapy in comparison with the three dimensional conformal radiotherapy on the preservation of organs at risk in regard of the delivered dose to tumors justifying an accelerated hypo fractionation and a dose escalation. This automatic segmentation atlas should allow to establish correlations between anatomy and cerebral dosimetry; This atlas allows to underline the dosimetry optimization by stereotaxic radiotherapy robotized for organs at risk. (N.C.)

Dosimetry comparison of irradiation with conformal radiotherapy, intensity modulated radiotherapy, conformal radiotherapy in stereotactic conditions and robotic stereotactic radiotherapy for benign brain tumours

International Nuclear Information System (INIS)

Spasic, E.; Noel, A.; Buchheit, I.; Bernier, V.

2011-01-01

Purpose. - To compare several techniques in order to determine the best treatment for benign brain tumours. Methods and patients. - A retrospective study was performed for five patients who received 3D-conformal radiotherapy, intensity modulated radiotherapy or CyberKnife R . These patients had a meningioma, a pituitary tumour, a cranio-pharyngioma or a neurinoma. In each case, these treatment plans were optimised and compared with the three other dosimetries. Radiobiological or positioning parameters were evaluated, as well as dosimetric parameters, in order to compare treatments with different characteristics. Results. - The dosimetric parameters showed that the choice of treatment seemed to be determined mostly by tumour size, shape and proximity with organs at risk (not tumour localisation). Whereas the results showed no significant deviations with regards to the radiobiological parameters. Therefore, with these parameters, it was difficult to give priority to a treatment. Conclusions. - With regards to benign brain tumours of medium or large size, intensity modulated radiotherapy seemed the recommended treatment. It enabled to obtain a good ratio between efficacy and toxicity for tumours that are really close to organs at risk. Concerning small benign brain tumours, the CyberKnife R was probably the best treatment. (authors)

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.

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

Pelvic Ewing sarcomas. Three-dimensional conformal vs. intensity-modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Mounessi, F.S.; Lehrich, P.; Haverkamp, U.; Eich, H.T. [Muenster Univ. (Germany). Dept. of Radiation Oncology; Willich, N. [Muenster Univ. (Germany). Dept. of Radiation Oncology; Universitaetsklinikum Muenster (Germany). RiSK - Registry for the Evaluation of Late Side Effects after Radiotherapy in Childhood and Adolescence; Boelling, T. [Center for Radiation Oncology, Osnabrueck (Germany)

2013-04-15

The goal of the present work was to assess the potential advantage of intensity-modulated radiotherapy (IMRT) over three-dimensional conformal radiotherapy (3D-CRT) planning in pelvic Ewing's sarcoma. A total of 8 patients with Ewing sarcoma of the pelvis undergoing radiotherapy were analyzed. Plans for 3D-CRT and IMRT were calculated for each patient. Dose coverage of the planning target volume (PTV), conformity and homogeneity indices, as well as further parameters were evaluated. Results The average dose coverage values for PTV were comparable in 3D-CRT and IMRT plans. Both techniques had a PTV coverage of V{sub 95} > 98 % in all patients. Whereas the IMRT plans achieved a higher conformity index compared to the 3D-CRT plans (conformity index 0.79 {+-} 0.12 vs. 0.54 {+-} 0.19, p = 0.012), the dose distribution across the target volumes was less homogeneous with IMRT planning than with 3D-CRT planning. This difference was statistically significant (homogeneity index 0.11 {+-} 0.03 vs. 0.07 {+-} 0.0, p = 0.035). For the bowel, D{sub mean} and D{sub 1%}, as well as V{sub 2} to V{sub 60} were reduced in IMRT plans. For the bladder and the rectum, there was no significant difference in D{sub mean}. However, the percentages of volumes receiving at least doses of 30, 40, 45, and 50 Gy (V{sub 30} to V{sub 50}) were lower for the rectum in IMRT plans. The volume of normal tissue receiving at least 2 Gy (V{sub 2}) was significantly higher in IMRT plans compared with 3D-CRT, whereas at high dose levels (V{sub 30}) it was significantly lower. Compared to 3D-CRT, IMRT showed significantly better results regarding dose conformity (p = 0.012) and bowel sparing at dose levels above 30 Gy (p = 0.012). Thus, dose escalation in the radiotherapy of pelvic Ewing's sarcoma can be more easily achieved using IMRT. (orig.)

External Beam Radiotherapy of Recurrent Glioma: Radiation Tolerance of the Human Brain

Energy Technology Data Exchange (ETDEWEB)

Sminia, Peter, E-mail: p.sminia@vumc.nl [Department of Radiation Oncology, Radiobiology Section, VU University Medical Center, De Boelelaan 1117, P.O. Box 7057, Amsterdam (Netherlands); Mayer, Ramona [EBG MedAustron GmbH., Viktor Kaplan-Strasse 2, A-2700, Wiener Neustadt (Austria)

2012-04-05

Malignant gliomas relapse in close proximity to the resection site, which is the postoperatively irradiated volume. Studies on re-irradiation of glioma were examined regarding radiation-induced late adverse effects (i.e., brain tissue necrosis), to obtain information on the tolerance dose and treatment volume of normal human brain tissue. The studies were analyzed using the linear-quadratic model to express the re-irradiation tolerance in cumulative equivalent total doses when applied in 2 Gy fractions (EQD2{sub cumulative}). Analysis shows that the EQD2{sub cumulative} increases from conventional re-irradiation series to fractionated stereotactic radiotherapy (FSRT) to LINAC-based stereotactic radiosurgery (SRS). The mean time interval between primary radiotherapy and the re-irradiation course was shortened from 30 months for conventional re-irradiation to 17 and 10 months for FSRT and SRS, respectively. Following conventional re-irradiation, radiation-induced normal brain tissue necrosis occurred beyond an EQD2{sub cumulative} around 100 Gy. With increasing conformality of therapy, the smaller the treatment volume is, the higher the radiation dose that can be tolerated. Despite the dose escalation, no increase in late normal tissue toxicity was reported. On basis of our analysis, the use of particle therapy in the treatment of recurrent gliomas, because of the optimized physical dose distribution in the tumour and surrounding healthy brain tissue, should be considered for future clinical trials.

External Beam Radiotherapy of Recurrent Glioma: Radiation Tolerance of the Human Brain

Directory of Open Access Journals (Sweden)

Peter Sminia

2012-04-01

Full Text Available Malignant gliomas relapse in close proximity to the resection site, which is the postoperatively irradiated volume. Studies on re-irradiation of glioma were examined regarding radiation-induced late adverse effects (i.e., brain tissue necrosis, to obtain information on the tolerance dose and treatment volume of normal human brain tissue. The studies were analyzed using the linear-quadratic model to express the re-irradiation tolerance in cumulative equivalent total doses when applied in 2 Gy fractions (EQD2cumulative. Analysis shows that the EQD2cumulative increases from conventional re-irradiation series to fractionated stereotactic radiotherapy (FSRT to LINAC-based stereotactic radiosurgery (SRS. The mean time interval between primary radiotherapy and the re-irradiation course was shortened from 30 months for conventional re-irradiation to 17 and 10 months for FSRT and SRS, respectively. Following conventional re-irradiation, radiation-induced normal brain tissue necrosis occurred beyond an EQD2cumulative around 100 Gy. With increasing conformality of therapy, the smaller the treatment volume is, the higher the radiation dose that can be tolerated. Despite the dose escalation, no increase in late normal tissue toxicity was reported. On basis of our analysis, the use of particle therapy in the treatment of recurrent gliomas, because of the optimized physical dose distribution in the tumour and surrounding healthy brain tissue, should be considered for future clinical trials.

Digital test objects (D.T.O.) for treatment planning systems quality control in external beam radiotherapy

International Nuclear Information System (INIS)

Denis, E.

2008-04-01

This work presents the conception and implementation of new automatic and quantitative quality assessment methods for geometric treatment planning in external radiotherapy. Treatment planning Systems (T.P.S.) quality control is mandatory in France and in the world because of encountered risks but the physical tools recommended to lead this quality control are not adapted to the situation. We present a new methodology for control quality based on the definition of Digital Test Objects (D.T.O.) that are directly introduced in the T.P.S. without acquisition device. These D.T.O. are consistently defined in a continuous and discrete modes. The T.P.S. responses to input D.T.O. are compared to theoretical results thanks to figures of merit specifically designed for each elementary control. The tests we carried out during this study allow to validate our solutions for the quality assessment of the auto-contouring, auto-margining, isocenter computation, collimator conformation and digitally reconstructed radiograph generation tools, as well as our solutions for marker positioning, collimator and displayed bean rotation, incidence, divergence and dimensions. Quality assessment solutions we propose are then fast and effective (no acquisition by the device, reduced manipulations), and more precise thanks to the continuous-discrete equivalence realized at the beginning of the modelling

Dosimetry quality audit of high energy photon beams in greek radiotherapy centers

International Nuclear Information System (INIS)

Hourdakis, Constantine J.; Boziari, A.

2008-01-01

Background and purpose: Dosimetry quality audits and intercomparisons in radiotherapy centers is a useful tool in order to enhance the confidence for an accurate therapy and to explore and dissolve discrepancies in dose delivery. This is the first national comprehensive study that has been carried out in Greece. During 2002 - 2006 the Greek Atomic Energy Commission performed a dosimetry quality audit of high energy external photon beams in all (23) Greek radiotherapy centers, where 31 linacs and 13 Co-60 teletherapy units were assessed in terms of their mechanical performance characteristics and relative and absolute dosimetry. Materials and Methods: The quality audit in dosimetry of external photon beams took place by means of on-site visits, where certain parameters of the photon beams were measured, calculated and assessed according to a specific protocol and the IAEA TRS 398 dosimetry code of practice. In each radiotherapy unit (Linac or Co-60), certain functional parameters were measured and the results were compared to tolerance values and limits. Doses in water under reference and non reference conditions were measured and compared to the stated values. Also, the treatment planning systems (TPS) were evaluated with respect to irradiation time calculations. Results: The results of the mechanical tests, dosimetry measurements and TPS evaluation have been presented in this work and discussed in detail. This study showed that Co-60 units had worse performance mechanical characteristics than linacs. 28% of all irradiation units (23% of linacs and 42% of Co-60 units) exceeded the acceptance limit at least in one mechanical parameter. Dosimetry accuracy was much worse in Co60 units than in linacs. 61% of the Co60 units exhibited deviations outside ±3% and 31% outside ±5%. The relevant percentages for the linacs were 24% and 7% respectively. The results were grouped for each hospital and the sources of errors (functional and human) have been investigated and

Dosimetry quality audit of high energy photon beams in greek radiotherapy centers.

Science.gov (United States)

Hourdakis, Constantine J; Boziari, A

2008-04-01

Dosimetry quality audits and intercomparisons in radiotherapy centers is a useful tool in order to enhance the confidence for an accurate therapy and to explore and dissolve discrepancies in dose delivery. This is the first national comprehensive study that has been carried out in Greece. During 2002--2006 the Greek Atomic Energy Commission performed a dosimetry quality audit of high energy external photon beams in all (23) Greek radiotherapy centers, where 31 linacs and 13 Co-60 teletherapy units were assessed in terms of their mechanical performance characteristics and relative and absolute dosimetry. The quality audit in dosimetry of external photon beams took place by means of on-site visits, where certain parameters of the photon beams were measured, calculated and assessed according to a specific protocol and the IAEA TRS 398 dosimetry code of practice. In each radiotherapy unit (Linac or Co-60), certain functional parameters were measured and the results were compared to tolerance values and limits. Doses in water under reference and non reference conditions were measured and compared to the stated values. Also, the treatment planning systems (TPS) were evaluated with respect to irradiation time calculations. The results of the mechanical tests, dosimetry measurements and TPS evaluation have been presented in this work and discussed in detail. This study showed that Co-60 units had worse performance mechanical characteristics than linacs. 28% of all irradiation units (23% of linacs and 42% of Co-60 units) exceeded the acceptance limit at least in one mechanical parameter. Dosimetry accuracy was much worse in Co60 units than in linacs. 61% of the Co60 units exhibited deviations outside +/-3% and 31% outside +/-5%. The relevant percentages for the linacs were 24% and 7% respectively. The results were grouped for each hospital and the sources of errors (functional and human) have been investigated and discussed in details. This quality audit proved to be a

A comparative study of external radiotherapy alone versus external radiotherapy + brachytherapy in carcinoma cervix stage III B

International Nuclear Information System (INIS)

Bardia, M.R.; Bhargava, S.C.; Chaudhary, R.K.; Agrawal, V.K.; Singh, K.; Vyas, R.

1987-01-01

Carcinoma of the cervix is the commonest cancer seen in women at Sardar Patel Medical College, Bikaner (Rajasthan). In the present study external radio-therapy and brachytherapy are used in carcinoma cervix stage III B. After 4000 to 4500 rads to pelvis by external radio-therapy, patient was assessed for intra cavitary application. Total given dose to point A was 7500 rads, to point B was 5000 rads. If patient was not suitable a split course was given where patient was asked to come after 3 weeks for intracavitary application. A comparative study of both methods was done. There was significant improvement in the control of central disease by applying intracavitary source. Radiation reactions were comparable. (author). 4 tables, 10 refs

Validation of an amino-acid-based radionuclide therapy plus external beam radiotherapy in heterotopic glioblastoma models

Energy Technology Data Exchange (ETDEWEB)

Israel, Ina [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Blass, Georg [Department of Radiotherapy and Radiooncology, Saarland University Medical Center, Homburg (Germany); Reiners, Christoph [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Samnick, Samuel, E-mail: samnick_s@klinik.uni-wuerzburg.d [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany)

2011-05-15

Background and purpose: Malignant gliomas represent a major therapeutic challenge because no efficient treatment is currently available. p-[{sup 131}I]iodo-L-phenylalanine ([{sup 131}I]IPA) is a glioma avid radiopharmaceutical that demonstrated antiproliferative and tumoricidal effects in gliomas. The present study validated the therapeutic efficiency of [{sup 131}I]IPA combined with external beam radiotherapy in experimental gliomas. Materials and methods: Glioma cells derived from the primary human A1207, T5135, Tx3868 and M059K glioblastoma cell lines or rat F98 glioma cell line were treated with various doses of [{sup 131}I]IPA, external photon irradiation (RT) or combined [{sup 131}I]IPA/RT treatment. Responsiveness of glioma cells to the different therapy modalities was investigated at 24, 48 and 72 h after treatments by trypan blue, WST-1 assay, propidium iodide and bisbenzimide staining as well as by clonogenic assay. In addition, the therapy-induced DNA damage and repair were evaluated using phosphorylated histone H2AX ({gamma}-H2AX). In vivo, the effectiveness of the combination treatment was validated in human Tx3868 and A1207 glioblastoma xenografts in CD1 nu/nu mice and RNU rats. Results: In vitro, the combination treatment resulted in a greater than additive increase in cytotoxic effect in glioma cell lines. Cell survival rate following a treatment with 1.0 {mu}Ci (37 kBq) of [{sup 131}I]IPA amounted to 70%{+-}15% and 60%{+-}10% after 48 and 72 h, respectively, and decreased under 20% after additional RT with 5 Gy. At higher RT doses, cell survival rate decreased below 5%. As a measure of DNA double-strand break, nuclear {gamma}-H2AX foci were determined as a function of time. Within 24 h, the number of {gamma}-H2AX foci per cell was significantly greater after combined modality compared with the individual treatments. In vivo, when combined with RT, the radionuclide therapy with [{sup 131}I]IPA resulted in an extended tumor growth delay, a reduction

Ocular complications after external-beam irradiation - a literature overview

International Nuclear Information System (INIS)

Ziolkowska, E.; Zarzycka, M.; Wisniewski, T.; Meller, A.

2009-01-01

Radiotherapy is one of the treatment methods applied to patients suffering from head and neck cancer. The efficiency of this method is comparable to surgery, yet it allows one to save the organ and avoid its permanent deformation. In the case of radiation not only the tumour is influenced but the surrounding, normal structures as well. Radiation causes deformation of normal structures as early or side effects. The aim of this study is to present plausible ocular complications after external beam irradiation of head and neck cancer, such as radiation- induced cataract, radiation retinopathy, dry-eye syndrome or radiation neuropathy. By the use of basic principles of radiotherapy planning we can avoid or minimize possible ocular complications occurring after irradiation. The treatment of ocular complications is difficult and very often does not give the expected outcome. Therefore, in such cases in order to restore vision surgery is required. This study shows that radiotherapy can be helpful but can increase the risk of occurrence of some ocular complications. (authors)

Muscle invasive bladder cancer treated by transurethral resection, followed by external beam radiation and interstitial iridium-192

NARCIS (Netherlands)

A. Wijnmaalen (Arendjan); P.A. Helle (Peter); P.C.M. Koper (Peter); P.P. Jansen (Peter); P. Hanssens (Patrick); C.G.G. Boeken Kruger (Cornelis); W.L.J. van Putten (Wim)

1997-01-01

textabstractPurpose: To evaluate the results of transurethral resection (TUR), external beam radiotherapy (EBRT), and interstitial radiation (IRT) with iridium-192, using the afterloading technique in patients with muscle invasive bladder cancer. Methods and Materials: From May 1989 until September

Radiotherapy gel dosimetry

International Nuclear Information System (INIS)

Baldock, C.

2002-01-01

In radiotherapy, the primary objective is to deliver a prescribed dose of radiation to a tumour or lesion within a patient while minimising the dose delivered to the surrounding healthy tissue. Traditional radiotherapy treatments usually involve simple external or internal irradiations of a tumour. External irradiations are normally achieved in the clinic with photon or electron beams produced by high energy linear accelerators. The photon or electron beams are collimated into regular shapes as they emerge from the treatment head of the unit which is supported by a gantry that can be rotated isocentrically to any position. A discrete number of photon or electron beams with different angles of incidence that intersect at the iso-centre are used to produce a region of high dose around the tumour volume (positioned at the iso-centre). Internal irradiations are normally achieved in the clinic by implanting radioactive sources in and around the tumour or lesion. Such irradiations are characterised by very high doses local to the tumour. Radioactive sources are also used to prevent post-angioplasty restenosis by inserting sources into arteries. Usually when treating a tumour, a compromise is made between tumour control and complications arising from normal tissue damage. One measure of this compromise, the therapeutic ratio, is defined as the radiation dose producing complications in 50% of patients divided by the dose providing tumour control in 50% of the patients. The therapeutic ratio depends on the radiobiological characteristics of the cancerous tissue and surrounding healthy tissues and on the radiation dose distribution achieved by the radiotherapy treatment. It is generally believed that the therapeutic ratio can be minimised by optimising the conformation of the radiation dose distribution to the target volume. This is difficult with traditional radiotherapy techniques since they do not produce dose distributions that adequately cover tumour volumes of complex

Safety and Efficacy of Thoracic External Beam Radiotherapy After Airway Stenting in Malignant Airway Obstruction

Energy Technology Data Exchange (ETDEWEB)

Rochet, Nathalie, E-mail: nrochet@partners.org [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Hauswald, Henrik; Schmaus, Martina; Hensley, Frank [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Huber, Peter [Department of Radiotherapy, German Cancer Research Center, Heidelberg (Germany); Eberhardt, Ralf; Herth, Felix J. [Department of Pulmonology and Respiratory Care Medicine, Thoraxklinik at University of Heidelberg, Heidelberg (Germany); Debus, Juergen; Neuhof, Dirk [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany)

2012-05-01

Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction. Methods and Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days. A median total dose of 50 Gy was delivered. Sixty-seven percent of the patients had reduced performance status (Karnofsky performance score, {<=}70). Results: EBRT had to be stopped prematurely in 16 patients (37%), at a median total dose of 17 Gy, for various reasons. In this group of patients, the survival was poor, with a median overall survival (OS) of only 21 days. Twenty-seven patients (63%) completed radiotherapy as planned, with a median OS of 8.4 months. Fourteen of 43 patients (33%) developed at least one Common Terminology Criteria for Adverse Event of grade 3 to 5. The most common event was a malignant restenosis of the stent leading to asphyxia (n = 7), followed by fistula formation (n = 4), necrosis (n = 3), mediastinitis with abscess (n = 1), secondary nonmalignant airway stenosis (n = 1), and hemoptysis (n = 1). With the exception of one event, all events were associated with a local progression of the tumor. Conclusions: Although the long-term prognosis for patients with malignant airway obstruction is poor, airway stenting combined with EBRT offers a possible therapeutic option, achieving fast relief of acute respiratory distress with an associated antitumor effect, resulting in a potential survival benefit. However, due to local advanced tumor growth, increased rates of adverse events are to be expected, necessitating careful monitoring.

Safety and Efficacy of Thoracic External Beam Radiotherapy After Airway Stenting in Malignant Airway Obstruction

International Nuclear Information System (INIS)

Rochet, Nathalie; Hauswald, Henrik; Schmaus, Martina; Hensley, Frank; Huber, Peter; Eberhardt, Ralf; Herth, Felix J.; Debus, Juergen; Neuhof, Dirk

2012-01-01

Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction. Methods and Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days. A median total dose of 50 Gy was delivered. Sixty-seven percent of the patients had reduced performance status (Karnofsky performance score, ≤70). Results: EBRT had to be stopped prematurely in 16 patients (37%), at a median total dose of 17 Gy, for various reasons. In this group of patients, the survival was poor, with a median overall survival (OS) of only 21 days. Twenty-seven patients (63%) completed radiotherapy as planned, with a median OS of 8.4 months. Fourteen of 43 patients (33%) developed at least one Common Terminology Criteria for Adverse Event of grade 3 to 5. The most common event was a malignant restenosis of the stent leading to asphyxia (n = 7), followed by fistula formation (n = 4), necrosis (n = 3), mediastinitis with abscess (n = 1), secondary nonmalignant airway stenosis (n = 1), and hemoptysis (n = 1). With the exception of one event, all events were associated with a local progression of the tumor. Conclusions: Although the long-term prognosis for patients with malignant airway obstruction is poor, airway stenting combined with EBRT offers a possible therapeutic option, achieving fast relief of acute respiratory distress with an associated antitumor effect, resulting in a potential survival benefit. However, due to local advanced tumor growth, increased rates of adverse events are to be expected, necessitating careful monitoring.

Image-guided radiotherapy in near real time with intensity-modulated radiotherapy megavoltage treatment beam imaging.

Science.gov (United States)

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

2009-10-01

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

Clinical Studies on conformal radiotherapy combined with epidermal ...

African Journals Online (AJOL)

Purpose: To study the effect of conformal radiotherapy combined with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) in the second-line treatment of non-small cell lung cancer (NSCLC). Methods: A total of 316 patients attending Shanghai Pulmonary Hospital affiliated to Tongji University, were divided ...

Controversies in external beam and high dose rate brachytherapy of oesophageal cancer

International Nuclear Information System (INIS)

Sur, R.K.; Levin, V.C.; Malas, Simon; Donde, Bernard

1994-01-01

Various controversies in the treatment of oesophageal carcinoma with external beam radiotherapy and high dose rate intracavitary irradiation have been reviewed. Conflicting results from different parts of the world has made it difficult to optimize the radiation dose that may give the best results. More studies and longer follow-up are needed before a definite conclusion can be made on the optimization of dose. (author). 18 refs., 2 tabs

Salvage conformal radiotherapy for biochemical recurrent prostate cancer after radical prostatectomy

Directory of Open Access Journals (Sweden)

Carlos R. Monti

2006-08-01

Full Text Available OBJECTIVE: Assess the results of salvage conformal radiotherapy in patients with biochemical failure after radical prostatectomy and identify prognostic factors for biochemical recurrence and toxicity of the treatment. MATERIALS AND METHODS: From June 1998 to November 2001, 35 patients were submitted to conformal radiotherapy for PSA > 0.2 ng/mL in progression after radical prostatectomy and were retrospectively analyzed. The mean dose of radiation in prostatic bed was of 77.4 Gy (68-81. Variables related to the treatment and to tumor were assessed to identify prognostic factors for biochemical recurrence after salvage radiotherapy. RESULTS: The median follow-up was of 55 months (17-83. The actuarial survival rates free of biochemical recurrence and free of metastasis at a distance of 5 years were 79.7% e 84.7%, respectively. The actuarial global survival rate in 5 years was 96.1%.The actuarial survival rate free of biochemical recurrence in 5 years was 83.3% with PSA pre-radiotherapy 1 and 2 (p = 0.023. Dose > 70 Gy in 30% of the bladder volume implied in more acute urinary toxicity (p = 0.035. The mean time for the development of late urinary toxicity was 21 months (12-51. Dose > 55 Gy in 50% bladder volume implied in more late urinary toxicity (p = 0.018. A patient presented late rectal toxicity of 2nd grade. CONCLUSIONS: Conformal radiotherapy showed to be effective for the control of biochemical recurrence after radical prostatectomy. Patients with pre-therapy PSA < 2 ng/mL have more biochemical control.

WE-E-213AB-01: Medical Physics Challenges for Implementation of New Technologies in External Beam Radiotherapy.

Science.gov (United States)

Boiras, C; Bourland, J; Gonzalez, L Brualla; Bulychkin, P; Ford, E; Kazantsev, P; Krylova, T; Medina, A Lopez; Prusova, M; Romanov, D; Ferrando, J Rosello; Willoughby, T; Yan, D; Yu, C; Zvereva, A

2012-06-01

The AAPM has signed two formal Educational Exchange Agreements with the Spanish (SEFM) and the Russian (AMPR) medical physics societies. While the primary purpose of the Agreements is to provide educational opportunities for young medical physicists, the Agreements also contemplate holding joint sessions at scientific congresses. The purpose of this professional AAPM/SEFM/AMPR Joint Symposium is to explore the challenges that medical physicists in the three countries face when new external beam radiotherapy technologies are introduced in their facilities and to suggest potential solutions to limitations in testing equipment and lack of familiarity with protocols. Speakers from the three societies will present reviews of the technical aspects of IMRT, Arc EVIRT (IMAT/VMAT/Rapid Arc), SRS/SRBT, and IGRT/Adaptive radiotherapy, and will describe the status of these technologies in their countries, including the challenges found in tasks such as developing anatomical and biological dose optimization techniques and implementing QA management, risk assessment and patient safety programs. The SEFM will offer AAPM and AMPR members the possibility to participate in collaborative proposals for future research bids in UE and USA based on an ongoing Spanish project for adaptive radiotherapy using functional imaging. A targeted discussion will debate three propositions: the cost/benefit ratio of IGRT, whether IMRT requires IGRT, and the use of non-ionizing radiation technologies for realtime monitoring of prostate IGRT. For these debates, each society has designated one speaker to present and defend either "For" or "Against" the proposition, followed by discussion by all participants. The Symposium presentations and the country-tailored recommendations drawn will be made available to each society for inclusion in their websites. The WGNIMP, the AAPM Work Group charged with executing the AAPM/SEFM and AAPM/AMPR Agreements, will follow up on the commitments made by the AAPM.Di Yan

Erectile function following brachytherapy, external beam radiotherapy, or radical prostatectomy in prostate cancer patients

International Nuclear Information System (INIS)

Putora, P.M.; Buchauer, K.; Plasswilm, L.; Engeler, D.; Schmid, H.P.; Haile, S.R.; Graf, N.

2016-01-01

For localized prostate cancer, treatment options include external beam radiotherapy (EBRT), radical prostatectomy (RP), and brachytherapy (BT). Erectile dysfunction (ED) is a common side-effect. Our aim was to evaluate penile erectile function (EF) before and after BT, EBRT, or RP using a validated self-administered quality-of-life survey from a prospective registry. Analysis included 478 patients undergoing RP (n = 252), EBRT (n = 91), and BT (n = 135) with at least 1 year of follow-up and EF documented using IIEF-5 scores at baseline, 6 weeks, 6 months, 1 year, and annually thereafter. Differences among treatments were most pronounced among patients with no or mild initial ED (IIEF-5 ≥ 17). Overall, corrected for baseline EF and age, BT was associated with higher IIEF-5 scores than RP (+ 7.8 IIEF-5 score) or EBRT (+ 3.1 IIEF-5 score). EBRT was associated with better IIEF-5 scores than RP (+ 4.7 IIEF-5 score). In patients undergoing EBRT or RP with bilateral nerve sparing (NS), recovery of EF was observed and during follow-up, the differences to BT were not statistically significant. Overall age had a negative impact on EF preservation (corrected for baseline IIEF). In our series, EF was adversely affected by each treatment modality. Considered overall, BT provided the best EF preservation in comparison to EBRT or RP. (orig.) [de

Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

Science.gov (United States)

Johansson, Silvia; Åström, Lennart; Sandin, Fredrik; Isacsson, Ulf; Montelius, Anders; Turesson, Ingela

2012-01-01

Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT) of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT). The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU) and gastrointestinal (GI) toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity. PMID:22848840

Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

Directory of Open Access Journals (Sweden)

Silvia Johansson

2012-01-01

Full Text Available Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT. The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU and gastrointestinal (GI toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity.

Diode In-vivo Dosimetry for External Beam Radiotherapy: Patient Data Analysis

International Nuclear Information System (INIS)

Mrcela, I.; Bokulic, T.; Budanec, M; Froebe, A.; Soldic, Z.; Kusic, Z.

2008-01-01

In-vivo dosimetry is known as simple and reliable method for checking the final accuracy of the dose delivered in external radiotherapy making a supplement to the regular quality control. Entrance dose measurements in the beginning of the treatment assure detection of major errors that can affect the therapy outcome. Silicon diodes are often the detectors of choice for their ability of real time dose measurements and the simplicity of use. There are many publications describing the procedures for the implementation of in-vivo dosimetry. Routine in-vivo dosimetry has been introduced in our department after initial procedures including physical characterization, calibration and determination of correction factors for the detectors in use. This work presents patient data analysis with more than 700 field measurements taken in last 2 years period

Monitoring external beam radiotherapy using real-time beam visualization

Energy Technology Data Exchange (ETDEWEB)

Jenkins, Cesare H. [Department of Mechanical Engineering and Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Naczynski, Dominik J.; Yu, Shu-Jung S.; Xing, Lei, E-mail: lei@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305 (United States)

2015-01-15

Purpose: To characterize the performance of a novel radiation therapy monitoring technique that utilizes a flexible scintillating film, common optical detectors, and image processing algorithms for real-time beam visualization (RT-BV). Methods: Scintillating films were formed by mixing Gd{sub 2}O{sub 2}S:Tb (GOS) with silicone and casting the mixture at room temperature. The films were placed in the path of therapeutic beams generated by medical linear accelerators (LINAC). The emitted light was subsequently captured using a CMOS digital camera. Image processing algorithms were used to extract the intensity, shape, and location of the radiation field at various beam energies, dose rates, and collimator locations. The measurement results were compared with known collimator settings to validate the performance of the imaging system. Results: The RT-BV system achieved a sufficient contrast-to-noise ratio to enable real-time monitoring of the LINAC beam at 20 fps with normal ambient lighting in the LINAC room. The RT-BV system successfully identified collimator movements with sub-millimeter resolution. Conclusions: The RT-BV system is capable of localizing radiation therapy beams with sub-millimeter precision and tracking beam movement at video-rate exposure.

The management of carcinoma of the anal canal by external beam radiotherapy, experience in Vancouver 1971-1988

International Nuclear Information System (INIS)

Newman, G.; Calverley, D.C.; Acker, B.D.; Manji, M.; Hay, J.; Flores, A.D.

1992-01-01

From 1971 to 1988 72 cases of carcinoma of the anal canal were treated by external beam radiotherapy, most commonly by 5000 cGy in 20 fractions given over 4 weeks. The actuarial survival at 5 years was 66% and the disease specific survival 78%. Nine patients had inguinal node metastases at diagnosis; their 5-year disease specific survival was 75%. 63 Patients were inguinal node negative at presentation; their 5-year specific survival was 78%, by UICC 1987 staging: T 1 71%, T 2 88%, T 3 41%, T 4 42%. 17 Patients developed local recurrence; 10 were suitable for abdominoperineal resection which was successful in 7. The probability of local control was related to T stage. 13 patients were left with a colostomy because of recurrence, 2 had a colostomy for radiation damage and 4 had their local recurrence managed palliatively, without a colostomy. As a result, 53 of the 72 patients (74%) were left with a functional anus. Severe late complications occurred in 6 (8%). (author). 13 refs., 3 figs., 7 tabs

The management of carcinoma of the anal canal by external beam radiotherapy, experience in Vancouver 1971-1988

Energy Technology Data Exchange (ETDEWEB)

Newman, G. (Bristol Oncology Centre (United Kingdom)); Calverley, D.C.; Acker, B.D.; Manji, M.; Hay, J.; Flores, A.D. (British Columbia Cancer Inst., Vancouver, BC (Canada))

1992-11-01

From 1971 to 1988 72 cases of carcinoma of the anal canal were treated by external beam radiotherapy, most commonly by 5000 cGy in 20 fractions given over 4 weeks. The actuarial survival at 5 years was 66% and the disease specific survival 78%. Nine patients had inguinal node metastases at diagnosis; their 5-year disease specific survival was 75%. 63 Patients were inguinal node negative at presentation; their 5-year specific survival was 78%, by UICC 1987 staging: T[sub 1] 71%, T[sub 2] 88%, T[sub 3] 41%, T[sub 4] 42%. 17 Patients developed local recurrence; 10 were suitable for abdominoperineal resection which was successful in 7. The probability of local control was related to T stage. 13 patients were left with a colostomy because of recurrence, 2 had a colostomy for radiation damage and 4 had their local recurrence managed palliatively, without a colostomy. As a result, 53 of the 72 patients (74%) were left with a functional anus. Severe late complications occurred in 6 (8%). (author). 13 refs., 3 figs., 7 tabs.

External radiotherapy for bone and lymph-node metastases from thyroid cancer

International Nuclear Information System (INIS)

Niunoya, Koichiro; Kusakabe, Kiyoko; Obara, Takao; Ito, Yukio; Fujimoto, Yoshihide

2002-01-01

The therapeutic effects of external beam radiation to bone or lymph-node metastatic lesions of thyroid cancer were evaluated in 11 patients. These 11 cases included four male and seven female patients ranging in age from 44 to 69 years (mean age 54 years), were treated by 4MV-Xray irradiation. Thyroid surgery had been performed in all patients. The thyroid tumors were classified histologically as papillary carcinoma in 3 patients and follicular carcinoma in 8. Following surgical total thyroidectomy, thyroid ablation and/or therapy with I-131 was performed in 8 patients with follicular carcinoma. Using a 4MV-Xray external beam, a total dose of 54 to 68 Gy (mean dose 62 Gy) was delivered to 28 metastatic lesions including 2 lymph nodes and 26 bones, although an 82-Gy total dose was used for one lymph node. All patients underwent follow-up for more than 8 years. Ten of the 11 patients died, 6 of thyroid cancer and 4 of other diseases. Two of them suffered anaplastic transformation of differentiated thyroid carcinoma and died. The survival term was 0.2 to 8.6 years (mean 4.9 years) after initial external radiotherapy. Local irradiation with a curative dose was able to control most of the lesions in the 11 patients (29 lesions with the exception of 2 cases showing anaplastic transformation). In some patients, pain relief was obtained although tumor size measured by CT did not reveal marked regression. External beam radiation therapy with a curative dose was thought to be beneficial for patients with metastatic lesions of thyroid cancer as slow-growing and having relatively long survival period of patients. (author)

Optical eye tracking system for real-time noninvasive tumor localization in external beam radiotherapy.

Science.gov (United States)

Via, Riccardo; Fassi, Aurora; Fattori, Giovanni; Fontana, Giulia; Pella, Andrea; Tagaste, Barbara; Riboldi, Marco; Ciocca, Mario; Orecchia, Roberto; Baroni, Guido

2015-05-01

External beam radiotherapy currently represents an important therapeutic strategy for the treatment of intraocular tumors. Accurate target localization and efficient compensation of involuntary eye movements are crucial to avoid deviations in dose distribution with respect to the treatment plan. This paper describes an eye tracking system (ETS) based on noninvasive infrared video imaging. The system was designed for capturing the tridimensional (3D) ocular motion and provides an on-line estimation of intraocular lesions position based on a priori knowledge coming from volumetric imaging. Eye tracking is performed by localizing cornea and pupil centers on stereo images captured by two calibrated video cameras, exploiting eye reflections produced by infrared illumination. Additionally, torsional eye movements are detected by template matching in the iris region of eye images. This information allows estimating the 3D position and orientation of the eye by means of an eye local reference system. By combining ETS measurements with volumetric imaging for treatment planning [computed tomography (CT) and magnetic resonance (MR)], one is able to map the position of the lesion to be treated in local eye coordinates, thus enabling real-time tumor referencing during treatment setup and irradiation. Experimental tests on an eye phantom and seven healthy subjects were performed to assess ETS tracking accuracy. Measurements on phantom showed an overall median accuracy within 0.16 mm and 0.40° for translations and rotations, respectively. Torsional movements were affected by 0.28° median uncertainty. On healthy subjects, the gaze direction error ranged between 0.19° and 0.82° at a median working distance of 29 cm. The median processing time of the eye tracking algorithm was 18.60 ms, thus allowing eye monitoring up to 50 Hz. A noninvasive ETS prototype was designed to perform real-time target localization and eye movement monitoring during ocular radiotherapy treatments. The

The comparison of 5-field conformal radiotherapy techniques for the treatment of prostate cancer: The best for femoral head sparing

International Nuclear Information System (INIS)

Zare, Mahkameh; Lashkari, Marzieh; Ghalehtaki, Reza; Ghasemi, Arash; Dehghan Manshadi, Hamidreza; Mir, Ali; Noorollahi, Somayeh; Alamolhoda, Mahboobeh

2016-01-01

External radiotherapy is a standard treatment procedure for localized prostate cancer. Given the relatively high long term survival treatment complications have been brought in center of attention. In this planning study, between 2012 and 2014, CT simulation data of 90 consecutive high-risk prostate cancer patients were collected. In the first phase, all were planned for whole pelvis irradiation up to 46Gy in 23 daily fractions. In the second phase, only the prostate gland was the target of radiation. Next, the subjects were divided randomly into three groups and each received a unique 5field conformal radiation plan including Plan A (Gantry angle: 0, 60, 120, 240, and 300), Plan B (Gantry angles: 0, 90, 120, 240, and 270) and Plan C (Gantry angles: 0, 60, 90, 270, and 300). The total dose was 70Gy. For each patient, the rectum, bladder, and both femoral heads were contoured as the at risk organs (OAR). From dose volume histograms, the proportional dose of PTV V100, the bladder and rectum V80 and V90 and femoral head V50 and V100 were calculated in all subjects and compared across plans. A statistically significant difference in the femoral head V50 and V100 was found between our studied 5field plans so that in Plan A (beam angles: 0, 60, 120, 240 and 300) less dose was received by both heads of femur. This study suggests that 5 field treatment planning including an anterior, two anterior oblique and two posterior oblique portals to be more proper for 3D conformal radiotherapy in order to spare femoral head with acceptable PTV coverage, and bladder and rectal doses.

Prostate biopsy after definitive treatment by interstitial iodine 125 implant or external beam radiation therapy

International Nuclear Information System (INIS)

Schellhammer, P.F.; el-Mahdi, A.M.; Higgins, E.M.; Schultheiss, T.E.; Ladaga, L.E.; Babb, T.J.

1987-01-01

The response to definitive radiation therapy of localized carcinoma of the prostate by iodine 125 implantation or external beam radiotherapy was monitored by examining specimens from biopsies performed after treatment. We analyzed 126 biopsy specimens obtained 18 months or more after treatment: 71 were obtained from 109 patients treated by iodine 125 and 55 from 197 patients treated by external beam radiotherapy. Thereafter, the disease status of these patients was examined at minimum 3-year intervals. No significant statistical difference was found between the negative specimen rates of the 2 treatment modalities: 46 of 71 (65 per cent) after iodine 125 implantation and 39 of 55 (71 per cent) after external beam radiotherapy were negative. To analyze the predictive value of biopsy results 103 patients whose prostatic examination results were normal at biopsy or who showed regression of tumor size and tumor induration after radiation were evaluated. The biopsy results from all patients were combined for analysis. Of 77 patients with negative biopsy specimens 16 (21 per cent) have had recurrent disease, compared to 17 of 26 (65 per cent) with positive biopsy specimens (p equals 0.00005). Of the 77 patients with negative biopsy specimens 7 (9 per cent) had local disease recurrence, compared to 12 of 26 (46 per cent) with a positive biopsy specimen (p equals 0.0001). The value of a positive specimen to predict failure remained significant with patients stratified by pre-treatment clinical stage and grade of the disease. Our results show that patients with positive specimens from the prostate who had been judged clinically by rectal examination to have responded to radiation therapy had a significantly increased incidence of local and distant failure compared to patients who had negative biopsy specimens

Salvage conformal radiotherapy for biochemical recurrent prostate cancer after radical prostatectomy

International Nuclear Information System (INIS)

Monti, Carlos R.; Nakamura, Ricardo A.; Ferrigno, Robson; Rossi Junior, Aristides; Kawakami, Neusa S.; Trevisan, Felipe A.

2006-01-01

Objective: Assess the results of salvage conformal radiotherapy in patients with biochemical failure after radical prostatectomy and identify prognostic factors for biochemical recurrence and toxicity of the treatment. Materials and methods: From June 1998 to November 2001, 35 patients were submitted to conformal radiotherapy for PSA ≥ 0.2 ng/mL in progression after radical prostatectomy and were retrospectively analyzed. The mean dose of radiation in prostatic bed was of 77.4 Gy (68-81). Variables related to the treatment and to tumor were assessed to identify prognostic factors for biochemical recurrence after salvage radiotherapy. Results: The median follow-up was of 55 months (17-83). The actuarial survival rates free of biochemical recurrence and free of metastasis at a distance of 5 years were 79.7% e 84.7%, respectively. The actuarial global survival rate in 5 years was 96.1%.The actuarial survival rate free of biochemical recurrence in 5 years was 83.3% with PSA pre-radiotherapy ≤ 1, 100% when > 1 and ≤ 2, and 57.1% when > 2 (p = 0.023). Dose > 70 Gy in 30% of the bladder volume implied in more acute urinary toxicity (p = 0.035). The mean time for the development of late urinary toxicity was 21 months (12-51). Dose > 55 Gy in 50% bladder volume implied in more late urinary toxicity (p = 0.018). A patient presented late rectal toxicity of second grade. Conclusions: Conformal radiotherapy showed to be effective for the control of biochemical recurrence after radical prostatectomy. Patients with pre-therapy PSA < 2 ng/mL have more biochemical control. (author)

Pattern of failures in gastric cancer patients with lymph node involvement treated by surgery, intraoperative and external beam radiotherapy

International Nuclear Information System (INIS)

Glehen, O.; Peyrat, P.; Beaujard, A.C.; Chapet, O.; Romestaing, P.; Sentenac, I.; Francois, Y.; Vignal, J.; Gerard, J.P.; Gilly, F.N.

2003-01-01

Aims: High local failure rates in gastric cancer have been reported, up to 67%. To achieve a better local control, we evaluated intraoperative radiotherapy (IORT) and external beam radiotherapy (EBRT) in association with surgery for gastric cancer patients with lymph node involvement. We report here the analysis of the patterns of failure for patients involved in this IORT protocol. Material and methods: Forty-two positive lymph node (N+) gastric cancer patients were operated on (31 total, three subtotal and eight extended gastrectomies) with IORT procedure between 1985 and 1997 (33 males, nine females, mean age 61.3 years). IORT was focused on coeliac area (mean dose 15 Gy), followed by EBRT (46 Gy) in 36 patients. Ten patients were pN1 and 32 were pN2. A concurrent systemic chemotherapy (five Fluoro-Uracil and Cisplatinum) was performed in 14 patients. Results: One patient died postoperatively. Actuarial pN+ 10 year survival rate was 44.8%. The 5 year actuarial local control and disease-free survival rates were 78.8 and 47.5%, respectively. As far as patterns of failure were explored, 5 patients have a local coeliac recurrence (12%) and 12 have distant metastases with no evidence of coeliac recurrence. Conclusion: This retrospective analysis suggests a potential effect of IORT and/or EBRT in promoting local control and long-term survival in gastric cancer patients with lymph node involvement

A computer-controlled conformal radiotherapy system I: overview

International Nuclear Information System (INIS)

Fraass, Benedick A.; McShan, Daniel L.; Kessler, Marc L.; Matrone, Gwynne M.; Lewis, James D.; Weaver, Tamar A.

1995-01-01

Purpose: Equipment developed for use with computer-controlled conformal radiotherapy (CCRT) treatment techniques, including multileaf collimators and/or computer-control systems for treatment machines, are now available. The purpose of this work is to develop a system that will allow the safe, efficient, and accurate delivery of CCRT treatments as routine clinical treatments, and permit modifications of the system so that the delivery process can be optimized. Methods and Materials: The needs and requirements for a system that can fully support modern computer-controlled treatment machines equipped with multileaf collimators and segmental or dynamic conformal therapy capabilities have been analyzed and evaluated. This analysis has been used to design and then implement a complete approach to the delivery of CCRT treatments. Results: The computer-controlled conformal radiotherapy system (CCRS) described here consists of a process for the delivery of CCRT treatments, and a complex software system that implements the treatment process. The CCRS system described here includes systems for plan transfer, treatment delivery planning, sequencing of the actual treatment delivery process, graphical simulation and verification tools, as well as an electronic chart that is an integral part of the system. The CCRS system has been implemented for use with a number of different treatment machines. The system has been used clinically for more than 2 years to perform CCRT treatments for more than 200 patients. Conclusions: A comprehensive system for the implementation and delivery of computer-controlled conformal radiation therapy (CCRT) plans has been designed and implemented for routine clinical use with multisegment, computer-controlled, multileaf-collimated conformal therapy. The CCRS system has been successfully implemented to perform these complex treatments, and is considered quite important to the clinical use of modern computer-controlled treatment techniques

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Neoadjuvant androgen deprivation and long-term results for patients with intermediate- and high-risk prostate cancer treated with high-dose rate brachytherapy and external beam radiotherapy

International Nuclear Information System (INIS)

Pellizzon, Antonio Cassio Assis; Fogaroli, Ricardo Cesar; Silva, Maria Leticia Gobo; Castro, Douglas Guedes; Maia, Maria Conte

2010-01-01

Purpose: to evaluate the influence of neoadjuvant androgen deprivation (NAAD) and report the long term biochemical control rates according to the Phoenix Consensus Conference, and prognostic factors of intermediate- (IR) and high-risk (HR) prostate cancer treated with external beam radiotherapy and high-dose-rate brachytherapy (HDR-BT). Methods and materials: between March, 1997 and June, 2005, 184 patients considered IR or HR were treated with localized radiotherapy and HDR-BT at the Department of Radiation Oncology, Hospital A.C. Camargo, Sao Paulo, Brazil. Patient's age, Gleason score, clinical stage, initial PSA value, risk group for biochemical failure, presence of NAAD, doses of radiotherapy and HDR-BT were evaluated. Results: median age and follow-up were 70 years old (range, 47-83) and 74.5 months (range, 24-123 months), respectively. Patients considered IR were 91 (49.4%) and HR 93 (50.6%). Ninety-nine (53.8%) patients had no NAAD. The overall survival at 5 years was 93.6%. The 5-year actuarial biochemical control rates for all patients, IR and HR were 83.4%, 86.2% and 78.8%, respectively, p0.076. On univariate analysis the prognostic factors related to better biochemical control were Gleason score 45 Gy (p= 0.011) and HDR-BT dose > 20 Gy (p< 0.001). On multivariate analysis no statistical significant predictive factor related to biochemical control was found. Conclusions: the role of NAAD for IR and HR prostate cancer is still to be defined. HDR-BT combined to external radiotherapy is a successful form of treatment for these patients, with our results comparable to published data. (author)

Modelling normal tissue isoeffect distribution in conformal radiotherapy of glioblastoma provides an alternative dose escalation pattern through hypofractionation without reducing the total dose

International Nuclear Information System (INIS)

Mangel, L.; Skriba, Z.; Major, T.; Polgar, C.; Fodor, J.; Somogyi, A.; Nemeth, G.

2002-01-01

The purpose of this study was to prove that by using conformal external beam radiotherapy (RT) normal brain structures can be protected even when applying an alternative approach of biological dose escalation: hypofractionation (HOF) without total dose reduction (TDR). Traditional 2-dimensional (2D) and conformal 3-dimensional (3D) treatment plans were prepared for 10 gliomas representing the subanatomical sites of the supratentorial brain. Isoeffect distributions were generated by the biologically effective dose (BED) formula to analyse the effect of conventionally fractionated (CF) and HOF schedules on both the spatial biological dose distribution and biological dose-volume histograms. A comparison was made between 2D-CF (2.0 Gy/day) and 3D-HOF (2.5 Gy/day) regimens, applying the same 60 Gy total doses. Integral biologically effective dose (IBED) and volumes received biologically equivalent to a dose of 54 Gy or more (V-BED54) were calculated for the lower and upper brain stem as organs of risk. The IBED values were lower with the 3D-HOF than with the 2D-CF schedule in each tumour location, means 22.7±17.1 and 40.4±16.9 in Gy, respectively (p<0.0001). The V-BED54 values were also smaller or equal in 90% of the cases favouring the 3D-HOF scheme. The means were 2.7±4.8 ccm for 3D-HOF and 10.7±12.7 ccm for 2D-CF (p=0.0006). Our results suggest that with conformal RT, fraction size can gradually be increased. HOF radiotherapy regimens without TDR shorten the treatment time and seem to be an alternative way of dose escalation in the treatment of glioblastoma

Modelling normal tissue isoeffect distribution in conformal radiotherapy of glioblastoma provides an alternative dose escalation pattern through hypofractionation without reducing the total dose

Energy Technology Data Exchange (ETDEWEB)

Mangel, L.; Skriba, Z.; Major, T.; Polgar, C.; Fodor, J.; Somogyi, A.; Nemeth, G. [National Research Inst. for Radiobiology and Radiohygiene, Budapest (Hungary)

2002-04-01

The purpose of this study was to prove that by using conformal external beam radiotherapy (RT) normal brain structures can be protected even when applying an alternative approach of biological dose escalation: hypofractionation (HOF) without total dose reduction (TDR). Traditional 2-dimensional (2D) and conformal 3-dimensional (3D) treatment plans were prepared for 10 gliomas representing the subanatomical sites of the supratentorial brain. Isoeffect distributions were generated by the biologically effective dose (BED) formula to analyse the effect of conventionally fractionated (CF) and HOF schedules on both the spatial biological dose distribution and biological dose-volume histograms. A comparison was made between 2D-CF (2.0 Gy/day) and 3D-HOF (2.5 Gy/day) regimens, applying the same 60 Gy total doses. Integral biologically effective dose (IBED) and volumes received biologically equivalent to a dose of 54 Gy or more (V-BED54) were calculated for the lower and upper brain stem as organs of risk. The IBED values were lower with the 3D-HOF than with the 2D-CF schedule in each tumour location, means 22.7{+-}17.1 and 40.4{+-}16.9 in Gy, respectively (p<0.0001). The V-BED54 values were also smaller or equal in 90% of the cases favouring the 3D-HOF scheme. The means were 2.7{+-}4.8 ccm for 3D-HOF and 10.7{+-}12.7 ccm for 2D-CF (p=0.0006). Our results suggest that with conformal RT, fraction size can gradually be increased. HOF radiotherapy regimens without TDR shorten the treatment time and seem to be an alternative way of dose escalation in the treatment of glioblastoma.

Uterine cervix cancer treatment in IIB, IIIA and IIIB stages with external radiotherapy versus external radiotherapy and scintiscanning of low dose. ION SOLCA. Years 1998-2000

International Nuclear Information System (INIS)

Sanchez, Doris; Falquez, Roberto

2002-01-01

We realized study of retrospective accomplished in course of years 1998-2000, reviewing clinical charts of statistical department of ION SOLCA. We reviewed 544 cases in 1998, 603 patients in 1999, and 630 cases in 2000. In the radiotherapy service, 133 patients received treatment with external radiotherapy between February 1998 to February 1999 in IIB, IIIA, IIIB stages and only 80 patients were treated with external radiotherapy and scintiscanning of low dose rate in the same stages between March 1999 to March 2000. (The author)

Adjuvant radiotherapy for stage I endometrial cancer.

Science.gov (United States)

Kong, A; Johnson, N; Cornes, P; Simera, I; Collingwood, M; Williams, C; Kitchener, H

2007-04-18

The role of adjuvant radiotherapy (both pelvic external beam radiotherapy and vaginal intracavity brachytherapy) in stage I endometrial cancer following total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH and BSO) remains unclear. To assess the efficacy of adjuvant radiotherapy following surgery for stage I endometrial cancer. The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CancerLit, Physician Data Query (PDQ) of National Cancer Institute. Handsearching was also carried out where appropriate. Randomised controlled trials (RCTs) which compared adjuvant radiotherapy versus no radiotherapy following surgery for patients with stage I endometrial cancer were included. Quality of the studies was assessed and data collected using a predefined data collection form. The primary endpoint was overall survival. Secondary endpoints were locoregional recurrence, distant recurrence and endometrial cancer death. Data on quality of life (QOL) and morbidity were also collected. A meta-analysis on included trials was performed using the Cochrane Collaboration Review Manager Software 4.2. The meta-analysis was performed on four trials (1770 patients). The addition of pelvic external beam radiotherapy to surgery reduced locoregional recurrence, a relative risk (RR) of 0.28 (95% confidence interval (CI) 0.17 to 0.44, p ASTEC; Lukka) are awaited. External beam radiotherapy carries a risk of toxicity and should be avoided in stage 1 endometrial cancer patients with no high risk factors.

Role of adjuvant postoperative external beam radiotherapy for well differentiated thyroid cancer

Energy Technology Data Exchange (ETDEWEB)

Kwon, Jeanny; Wu, Hong Gyun; Youn, Yeo Kyu; Lee, Kyu Eun; Kim, Kwang Hyun; Park, Do Joon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2013-09-15

To analyze the outcome of adjuvant postoperative external beam radiotherapy (EBRT) in well-differentiated thyroid cancer (WDTC). We identified 84 patients treated with EBRT for WDTC from February 1981 to December 2010. Among them, we analyzed 39 patients who received EBRT after initial radical surgery. Twenty-four females and 15 males were included. The median age was 49 years (range, 16 to 72 years). There were 34 papillary thyroid carcinomas and 5 follicular thyroid carcinomas. Most patients showed pathologic T3/T4 stage (54%/26%). Ten patients (25.6%) had gross residual tumors. Five patients (12.8%) had tumor cells at the margin. The median EBRT dose and fraction size were 62.6 Gy and 1.8 to 2.0 Gy, respectively. The median follow-up was 73 months (range, 21 to 372 months). The five-year overall survival (OS) and locoregional recurrence free survival (LRFS) were 97.4% and 86.9%, respectively. Locoregional failures occurred in 5 and all failure sites were the neck node area. In univariate analysis, OS was significantly influenced by invasion of the trachea (p = 0.016) or esophagus (p = 0.006). LRFS was significantly decreased by male (p = 0.020), gross residuum after resection (p = 0.002), close or positive tumor at surgical margin involvement (p = 0.044), and tracheal invasion (p = 0.040). No significant prognostic factor was identified in the multivariate analysis. No patient experienced the Radiation Therapy Oncology Group grade 3 or more toxicity. Our locoregional control rate of 87.2% is comparable to historical controls with surgery alone, even though our study had a large proportion of advanced stage. Adjuvant EBRT may an effective and safe treatment option in patients with WDTC.

Health-Related Quality of Life After Single-Fraction High-Dose-Rate Brachytherapy and Hypofractionated External Beam Radiotherapy for Prostate Cancer

International Nuclear Information System (INIS)

Morton, Gerard C.; Loblaw, D. Andrew; Chung, Hans; Tsang, Gail; Sankreacha, Raxa; Deabreu, Andrea; Zhang Liying; Mamedov, Alexandre; Cheung, Patrick; Batchelar, Deidre; Danjoux, Cyril; Szumacher, Ewa

2011-01-01

Purpose: To investigate the change in health-related quality of life for men after high-dose-rate brachytherapy and external beam radiotherapy for prostate cancer and the factors associated with this change. Methods and Materials: Eligible patients had clinically localized intermediate-risk prostate cancer. The patients received high-dose-rate brachytherapy as a single 15-Gy implant, followed by external beam radiotherapy to 37.5 Gy in 15 fractions. The patients were monitored prospectively for toxicity (Common Terminology Criteria for Adverse Events, version 3.0) and health-related quality of life (Expanded Prostate Cancer Index Composite [EPIC]). The proportion of patients developing a clinically significant difference in the EPIC domain score (minimally important difference of >0.5 standard deviation) was determined and correlated with the baseline clinical and dosimetric factors. The study accrued 125 patients, with a median follow-up of 24 months. Results: By 24 months, 23% had Grade 2 urinary toxicity and only 5% had Grade 2 bowel toxicity, with no Grade 3 toxicity. The proportion of patients reporting a significant decrease in EPIC urinary, bowel, sexual, and hormonal domain scores was 53%, 51%, 45%, and 40% at 12 months and 57%, 65%, 51%, and 30% at 24 months, respectively. The proportion with a >1 standard deviation decrease in the EPIC urinary, bowel, sexual, and hormonal domain scores was 38%, 36%, 24%, and 20% at 12 months and 46%, 48%, 19%, and 8% at 24 months, respectively. On multivariate analysis, the dose to 10% of the urethra was associated with a decreasing EPIC urinary domain score (p = .0089) and, less strongly (p = .0312) with a decreasing hormonal domain score. No association was found between the prostate volume, bladder dose, or high-dose volume and urinary health-related quality of life. A high baseline International Index of Erectile Function score was associated (p = .0019) with a decreasing sexual domain score. The optimal maximal dose

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.

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

International Nuclear Information System (INIS)

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

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.

Situation of radiotherapy in 2010 - context and methods, data for 2003/2010, synthesis

International Nuclear Information System (INIS)

2011-03-01

Illustrated by data tables and figures, this report first gives an overview of the status and situation of European and French radiotherapy centres, and of care activity authorizations regarding external radiotherapy. It gives an overview of equipment used for treatments and for treatment preparation and delivery, and of the different treatment techniques (three dimensional conformational, intensity-modulated conformational, stereotactic, whole body radiotherapy, proton-therapy). It comments the activity of radiotherapy centres: patients (age, sessions, and treated pathologies), comments data regarding medical and paramedical personnel involved in radiotherapy, and financial data regarding radiotherapy in 2009

Conformal radiotherapy for 6 cases of bile duct carcinoma

International Nuclear Information System (INIS)

Kawasaki, Yoshiyuki; Suzuki, Takashi; Sugahara, Shinji

1998-01-01

Authors performed the conformal radiotherapy using the multileaf collimator for inoperable patients with bile duct carcinoma and examined the usefulness of this treatment. Forty one patients were examined, whose age was from 45 to 80 years (mean: 69.5 years), and whose ratio of men to women was 1 to 1.6. Patients in Group I (palliative irradiation, 30 cases) received bilateral irradiation using the linac with 4 MV-x-ray of total 50.0 Gy (2.0 Gy a dose, 5 times a week), those in Group II (palliative irradiation, 5 cases) using the microtron with 10 MV-x-ray of total 50.0 Gy (2.0 Gy a dose, 5 times a week). And those in Group III (radial irradiation, 6 cases) were first irradiated using the microtron with total 40.0 Gy (2.0 Gy a dose, 5 times a week) and secondly by the conformal radiotherapy with total 20.0 Gy (2.0 Gy a dose, 5 times a week). Patients in Group III were irradiated with total 60.0 Gy. Patients in all Groups showed mild side-effects including nausea and vomiting. And patients in Group III, who were irradiated 10 Gy more than other Group, showed no severe side-effects as alimentary bleeding, liver function disorders and cholangitis. In Group I, one year survivors were 3 (10.0%) and two years survivors were none. The median survival month was 7.2 months. In Group II, one year survivor was 1 (20.0%) and two years survivors were none. The median survival month was 8.1 months. In Group III, one year survivors were 2 (33.3%), and two years survivors were 2 (33.3%). The median survival month was 11.2 months. Two patients are survival at present (March, 1998), 2 years and 10 months, and 2 years and 9 months, respectively. The conformal radiotherapy gave better results than the ordinary radiotherapy. (K.H.)

Current External Beam Radiation Therapy Quality Assurance Guidance: Does It Meet the Challenges of Emerging Image-Guided Technologies?

International Nuclear Information System (INIS)

Palta, Jatinder R.; Liu, Chihray; Li, Jonathan G.

2008-01-01

The traditional prescriptive quality assurance (QA) programs that attempt to ensure the safety and reliability of traditional external beam radiation therapy are limited in their applicability to such advanced radiation therapy techniques as three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, inverse treatment planning, stereotactic radiosurgery/radiotherapy, and image-guided radiation therapy. The conventional QA paradigm, illustrated by the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 40 (TG-40) report, consists of developing a consensus menu of tests and device performance specifications from a generic process model that is assumed to apply to all clinical applications of the device. The complexity, variation in practice patterns, and level of automation of high-technology radiotherapy renders this 'one-size-fits-all' prescriptive QA paradigm ineffective or cost prohibitive if the high-probability error pathways of all possible clinical applications of the device are to be covered. The current approaches to developing comprehensive prescriptive QA protocols can be prohibitively time consuming and cost ineffective and may sometimes fail to adequately safeguard patients. It therefore is important to evaluate more formal error mitigation and process analysis methods of industrial engineering to more optimally focus available QA resources on process components that have a significant likelihood of compromising patient safety or treatment outcomes

Could 3-D conformal radiotherapy improve the overall survival for non-small cell lung cancer?

International Nuclear Information System (INIS)

Giraud, P.; Helfre, S.; Lavole, A.; Rosenwald, J.C.; Cosset, J.M.

2002-01-01

The conformal radiotherapy approach, three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT), is based on modern imaging modalities, efficient 3-D treatment planning systems, sophisticated immobilization devices and demanding quality assurance and treatment verification. The main goal of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of healthy tissues. These techniques would then allow a further dose escalation increasing local control and survival. Non-small cell lung cancer (NSCLC) is one of the most difficult malignant tumors to be treated. It combines geometrical difficulties due to respiratory motion, and number of low tolerance neighboring organs, and dosimetric difficulties because of the presence of huge inhomogeneities. This localization is an attractive and ambitious example for the evaluation of new techniques. However, the published clinical reports in the last years described very heterogeneous techniques and, in the absence of prospective randomized trials, it is somewhat difficult at present to evaluate the real benefits drawn from those conformal radiotherapy techniques. After reviewing the rationale for 3DCRT for NSCLC, this paper will describe the main studies of 3DCRT, in order to evaluate its impact on lung cancer treatment Then the current state-of-the-art of IMRT and the last technical and therapeutic innovations in NSCL will be discussed. (authors)

A randomized trial comparing hypofractionated and conventionally fractionated three-dimensional external-beam radiotherapy for localized prostate adenocarcinoma. A report on acute toxicity

Energy Technology Data Exchange (ETDEWEB)

Norkus, Darius; Miller, Albert; Kurtinaitis, Juozas; Valuckas, Konstantinas Povilas [Dept. of Radiotherapy, Inst. of Oncology, Vilnius Univ. (Lithuania); Haverkamp, Uwe [Dept. of Radiology, Clemenshospital, Muenster (Germany); Popov, Sergey [Dept. of Radiotherapy, Riga Eastern Hospital, Latvian Oncology Center, Riga (Latvia); Prott, Franz-Josef [Inst. of Radiology and Radiotherapy (RNS), St. Josefs Hospital, Wiesbaden (Germany)

2009-11-15

Purpose: to compare acute gastrointestinal (GI) and genitourinary (GU) toxicity between patient groups with localized prostate adenocarcinoma, treated with conventionally fractionated (CFRT) and hypofractionated (HFRT) three-dimensional conformal external-beam radiotherapy (3D-CRT). Patients and methods: 91 patients were enrolled into a randomized study with a minimum follow-up of 3 months. 44 men in the CFRT arm were irradiated with 74 Gy in 37 fractions at 2 Gy per fraction for 7.5 weeks. 47 men in the HFRT arm were treated with 57 Gy in 17 fractions for 3.5 weeks, given as 13 fractions of 3 Gy plus four fractions of 4.5 Gy. The clinical target volume (CTV) included the prostate and the base of seminal vesicles. The CTV-to-PTV (planning target volume) margin was 8-10 mm. Study patients had portal imaging and/or simulation performed on the first fractions and repeated at least weekly. Results: no acute grade 3 or 4 toxicities were observed. The grade 2 GU acute toxicity proportion was significantly lower in the HFRT arm: 19.1% versus 47.7% ({chi}{sup 2}-test, p = 0.003). The grade 2 GU acute toxicity-free survival was significantly better in the HFRT arm (log-rank test, p = 0.008). The median duration of overall GI acute toxicity was shorter with HFRT: 3 compared to 6 weeks with CFRT (median test, p = 0.017). Conclusion: in this first evaluation, the HFRT schedule is feasible and induces acceptable or even lower acute toxicity compared with the toxicities in the CFRT schedule. Extended follow-up is needed to justify this fractionation schedule's safety in the long term. (orig.)

Optimising measles virus-guided radiovirotherapy with external beam radiotherapy and specific checkpoint kinase 1 inhibition

International Nuclear Information System (INIS)

Touchefeu, Yann; Khan, Aadil A.; Borst, Gerben; Zaidi, Shane H.; McLaughlin, Martin; Roulstone, Victoria; Mansfield, David; Kyula, Joan; Pencavel, Tim; Karapanagiotou, Eleni M.; Clayton, Jamie; Federspiel, Mark J.; Russell, Steve J.; Garrett, Michelle; Collins, Ian; Harrington, Kevin J.

2013-01-01

Background and purpose: We previously reported a therapeutic strategy comprising replication-defective NIS-expressing adenovirus combined with radioiodide, external beam radiotherapy (EBRT) and DNA repair inhibition. We have now evaluated NIS-expressing oncolytic measles virus (MV-NIS) combined with NIS-guided radioiodide, EBRT and specific checkpoint kinase 1 (Chk1) inhibition in head and neck and colorectal models. Materials and methods: Anti-proliferative/cytotoxic effects of individual agents and their combinations were measured by MTS, clonogenic and Western analysis. Viral gene expression was measured by radioisotope uptake and replication by one-step growth curves. Potential synergistic interactions were tested in vitro by Bliss independence analysis and in in vivo therapeutic studies. Results: EBRT and MV-NIS were synergistic in vitro. Furthermore, EBRT increased NIS expression in infected cells. SAR-020106 was synergistic with EBRT, but also with MV-NIS in HN5 cells. MV-NIS mediated 131 I-induced cytotoxicity in HN5 and HCT116 cells and, in the latter, this was enhanced by SAR-020106. In vivo studies confirmed that MV-NIS, EBRT and Chk1 inhibition were effective in HCT116 xenografts. The quadruplet regimen of MV-NIS, virally-directed 131 I, EBRT and SAR-020106 had significant anti-tumour activity in HCT116 xenografts. Conclusion: This study strongly supports translational and clinical research on MV-NIS combined with radiation therapy and radiosensitising agents

Elevation of PSA after prostate radiotherapy: Rebound or biochemical recurrence?

International Nuclear Information System (INIS)

Toledano, A.; Kanoui, A.; Chiche, R.; Lamallem, H.; Beley, S.; Thibault, F.; Sebe, P.

2008-01-01

The fact that external beam radiotherapy and brachytherapy are now considered to be curative techniques has led to major review of the modalities of follow-up after radiotherapy for prostate cancer. The problem concerns both the diagnosis of recurrence, rapidly announced by elevation of prostatic-specific antigen (PSA), usually at a subclinical stage, and the validity of criteria of biochemical recurrence to allow comparison of various study. Physicians involved in follow-up should be aware of the potential of bounce in PSA follow-up after external beam radiotherapy or brachytherapy. The PSA bounce phenomenon was defined by a rise of PSA values (+ 0.1 -0.8 ng/ml) with a subsequent fall. Biochemical failure after external beam radiotherapy or brachytherapy (with or without hormonotherapy) was defined by Phoenix criteria by a rise of 2 ng/ml above an initial PSA nadir. This definition was more correlated to PSA bounce phenomenon. (authors)

Cardiac Exposure in the Dynamic Conformal Arc Therapy, Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy of Lung Cancer.

Directory of Open Access Journals (Sweden)

Xin Ming

Full Text Available To retrospectively evaluate the cardiac exposure in three cohorts of lung cancer patients treated with dynamic conformal arc therapy (DCAT, intensity-modulated radiotherapy (IMRT, or volumetric modulated arc therapy (VMAT at our institution in the past seven years.A total of 140 lung cancer patients were included in this institutional review board approved study: 25 treated with DCAT, 70 with IMRT and 45 with VMAT. All plans were generated in a same commercial treatment planning system and have been clinically accepted and delivered. The dose distribution to the heart and the effects of tumor laterality, the irradiated heart volume and the beam-to-heart distance on the cardiac exposure were investigated.The mean dose to the heart among all 140 plans was 4.5 Gy. Specifically, the heart received on average 2.3, 5.2 and 4.6 Gy in the DCAT, IMRT and VMAT plans, respectively. The mean heart doses for the left and right lung tumors were 4.1 and 4.8 Gy, respectively. No patients died with evidence of cardiac disease. Three patients (2% with preexisting cardiac condition developed cardiac disease after treatment. Furthermore, the cardiac exposure was found to increase linearly with the irradiated heart volume while decreasing exponentially with the beam-to-heart distance.Compared to old technologies for lung cancer treatment, modern radiotherapy treatment modalities demonstrated better heart sparing. But the heart dose in lung cancer radiotherapy is still higher than that in the radiotherapy of breast cancer and Hodgkin's disease where cardiac complications have been extensively studied. With strong correlations of mean heart dose with beam-to-heart distance and irradiated heart volume, cautions should be exercised to avoid long-term cardiac toxicity in the lung cancer patients undergoing radiotherapy.

Gastro-intestinal and genito-urinary morbidity after 3D conformal radiotherapy of prostate cancer: observations of a randomized trial

International Nuclear Information System (INIS)

Koper, Peter C.; Jansen, Peter; Putten, Wim van; Os, Marjolein van; Wijnmaalen, Arend J.; Lebesque, Joos V.; Levendag, Peter C.

2004-01-01

Background and purpose: The late morbidity of a randomized study was analyzed after a follow up of 2 years. The difference in intestinal morbidity was analyzed as a function of the treatment arm and dose volume parameters. The correlation with acute toxicity and (pre-existing) bowel complaints was investigated. Patients and methods: 266 T1-4N0M0 prostate cancer patients were randomized for conventional (open fields) and 3D conformal radiotherapy using beams eye view blocked fields with the same dose (66 Gy) and gross target volume-planning target volume margin (15 mm). Apart from the RTOG toxicity scoring system a patient self-assessment questionnaire was used to obtain detailed information on morbidity. Results: At 2 years there is only a trend for less rectal toxicity (grade≥1) in favor of the conformal radiotherapy (grade 1, 47 versus 40% and grade 2, 10 versus 7% for conventional and conformal radiotherapy, respectively (P=0.1). A significant relation was found between late rectal toxicity (grade≥1) and the volume of the anus and rectum exposed to≥90% tumor dose (TD). A highly significant relationship is observed between acute rectum and anal toxicity and late rectal toxicity. The patient self-assessment questionnaire analysis revealed that patients are most bothered by compliance related symptoms like urgency, soiling and fecal loss. In a multivariate analysis, all other variables loose significance, when anal volume exposed to≥90% TD and pre-treatment defaecation frequency are accounted for. Late anal toxicity is low and related only to acute anal toxicity. Late bladder toxicity is related solely to pre-treatment frequency and overall urological symptoms. The incidence of grade 2 toxicity increases with a factor 2.5-4 when (stool or urine) frequency is unfavorable at the start of treatment. Conclusions: Conformal radiotherapy at the dose level of 66 Gy does not significantly decrease the incidence of rectal, anal and bladder toxicity compared to

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

International Nuclear Information System (INIS)

Bazalova-Carter, Magdalena; Qu, Bradley; Palma, Bianey; Jensen, Christopher; Maxim, Peter G.; Loo, Billy W.; Hårdemark, Björn; Hynning, Elin

2015-01-01

plan, OAR doses were up to 70% lower and the integral dose was 33% lower for VHEE compared to 6 MV VMAT. Additionally, VHEE conformity indices (CI 100 = 1.09 and CI 50 = 4.07) were better than VMAT conformity indices (CI 100 = 1.30 and CI 50 = 6.81). The 100 MeV VHEE lung plan resulted in mean dose decrease to all OARs by up to 27% for the same target coverage compared to the clinical 6 MV flattening filter-free (FFF) VMAT plan. The 100 MeV prostate plan resulted in 3% mean dose increase to the penile bulb and the urethra, but all other OAR mean doses were lower compared to the 15 MV VMAT plan. The lung case CI 100 and CI 50 conformity indices were 3% and 8% lower, respectively, in the VHEE plan compared to the VMAT plan. The prostate case CI 100 and CI 50 conformity indices were 1% higher and 8% lower, respectively, in the VHEE plan compared to the VMAT plan. Conclusions: The authors have developed a treatment planning workflow for MC dose calculation of pencil beams and optimization for treatment planning of VHEE radiotherapy. The authors have demonstrated that VHEE plans resulted in similar or superior dose distributions for pediatric, lung, and prostate cases compared to clinical VMAT plans

Proton beam radiotherapy of iris melanoma

International Nuclear Information System (INIS)

Damato, Bertil; Kacperek, Andrzej; Chopra, Mona; Sheen, Martin A.; Campbell, Ian R.; Errington, R. Douglas

2005-01-01

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

Three-Dimensional Conformal Simultaneously Integrated Boost Technique for Breast-Conserving Radiotherapy

International Nuclear Information System (INIS)

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

2007-01-01

Purpose: To compare the target coverage and normal tissue dose with the simultaneously integrated boost (SIB) and the sequential boost technique in breast cancer, and to evaluate the incidence of acute skin toxicity in patients treated with the SIB technique. Methods and Materials: Thirty patients with early-stage left-sided breast cancer underwent breast-conserving radiotherapy using the SIB technique. The breast and boost planning target volumes (PTVs) were treated simultaneously (i.e., for each fraction, the breast and boost PTVs received 1.81 Gy and 2.3 Gy, respectively). Three-dimensional conformal beams with wedges were shaped and weighted using forward planning. Dose-volume histograms of the PTVs and organs at risk with the SIB technique, 28 x (1.81 + 0.49 Gy), were compared with those for the sequential boost technique, 25 x 2 Gy + 8 x 2 Gy. Acute skin toxicity was evaluated for 90 patients treated with the SIB technique according to Common Terminology Criteria for Adverse Events, version 3.0. Results: PTV coverage was adequate with both techniques. With SIB, more efficiently shaped boost beams resulted in smaller irradiated volumes. The mean volume receiving ≥107% of the breast dose was reduced by 20%, the mean volume outside the boost PTV receiving ≥95% of the boost dose was reduced by 54%, and the mean heart and lung dose were reduced by 10%. Of the evaluated patients, 32.2% had Grade 2 or worse toxicity. Conclusion: The SIB technique is proposed for standard use in breast-conserving radiotherapy because of its dose-limiting capabilities, easy implementation, reduced number of treatment fractions, and relatively low incidence of acute skin toxicity

Conformal Brachytherapy Boost To External Beam Irradiation For Clinically Localized High Risk Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Dattoli, Michael J; Wasserman, Stuart G; Koval, John M; Sorace, Richard A; Cash, Jennifer; Wallner, Kent E

1995-07-01

Purpose: To evaluate the efficacy of using a Pd-103 implant as a boost in conjunction with external beam radiotherapy (EBRT) in patients having prostate cancer associated with adverse features. Materials and Methods: 114 consecutive high risk patients have been treated with combination EBRT and Pd-103 implant. 70 patients with follow-up range of 12-42 months (median 24 months) form the basis of this report. Each patient had at least one of the following risk factors for extra-capsular disease extension: Stage T2b or greater ((66(70))), Gleason score {>=} 7 ((38(70))), significantly elevated PSA (typically > 15 ng/ml)((30(70))) or elevated serum prostatic acid phosphatase (SPAP)((17(70))). Patients received median 4140 cGy EBRT to a limited pelvic field followed by a Pd-103 boost (median prescription dose: 8000 cGy). All patients have been followed in a prospective fashion with respect to PSA response, clinical evidence of disease progression and complications. Criteria for biochemical failure was relatively strict, and was analyzed using both, PSA > 2.0 and PSA > 1.0 as end points. Patients whose PSA was still decreasing at last follow-up were censored at that time. Freedom from failure rates were calculated by the method of Kaplan and Meier. Differences between groups were determined by the Log-rank method. Sexual potency was defined as the ability to attain and maintain an erection sufficient for intercourse. Results: Actuarial freedom from biochemical failure at 3 years after treatment was 90% and 78%, when PSA > 2 and PSA > 1 were used, respectively. There are no documented local relapses. 4 patients failed distantly, and all other failures are based solely on rising PSA values. Biochemical failure was higher in patients having Gleason score {>=} 7 (p=0.001), those with PSA >20 (p=0.014) and in those with elevated SPAP (p=0.007). The primary treatment related morbity was temporary, Grade 1-2 urinary symptoms. No patient developed rectal ulceration or prostatic

Conformal Brachytherapy Boost To External Beam Irradiation For Clinically Localized High Risk Prostate Cancer

International Nuclear Information System (INIS)

Dattoli, Michael J.; Wasserman, Stuart G.; Koval, John M.; Sorace, Richard A.; Cash, Jennifer; Wallner, Kent E.

1995-01-01

Purpose: To evaluate the efficacy of using a Pd-103 implant as a boost in conjunction with external beam radiotherapy (EBRT) in patients having prostate cancer associated with adverse features. Materials and Methods: 114 consecutive high risk patients have been treated with combination EBRT and Pd-103 implant. 70 patients with follow-up range of 12-42 months (median 24 months) form the basis of this report. Each patient had at least one of the following risk factors for extra-capsular disease extension: Stage T2b or greater ((66(70))), Gleason score ≥ 7 ((38(70))), significantly elevated PSA (typically > 15 ng/ml)((30(70))) or elevated serum prostatic acid phosphatase (SPAP)((17(70))). Patients received median 4140 cGy EBRT to a limited pelvic field followed by a Pd-103 boost (median prescription dose: 8000 cGy). All patients have been followed in a prospective fashion with respect to PSA response, clinical evidence of disease progression and complications. Criteria for biochemical failure was relatively strict, and was analyzed using both, PSA > 2.0 and PSA > 1.0 as end points. Patients whose PSA was still decreasing at last follow-up were censored at that time. Freedom from failure rates were calculated by the method of Kaplan and Meier. Differences between groups were determined by the Log-rank method. Sexual potency was defined as the ability to attain and maintain an erection sufficient for intercourse. Results: Actuarial freedom from biochemical failure at 3 years after treatment was 90% and 78%, when PSA > 2 and PSA > 1 were used, respectively. There are no documented local relapses. 4 patients failed distantly, and all other failures are based solely on rising PSA values. Biochemical failure was higher in patients having Gleason score ≥ 7 (p=0.001), those with PSA >20 (p=0.014) and in those with elevated SPAP (p=0.007). The primary treatment related morbity was temporary, Grade 1-2 urinary symptoms. No patient developed rectal ulceration or prostatic

Breast conserving surgery in combination with intraoperative radiotherapy after previous external beam therapy: an option to avoid mastectomy.

Science.gov (United States)

Thangarajah, F; Heilmann, J; Malter, W; Kunze, S; Marnitz, S; Mallmann, P; Wenz, F; Sperk, E

2018-04-01

Mastectomy is the standard procedure in patients with in-breast tumor recurrence (IBTR) or breast cancer after irradiation of the chest due to Hodgkin's disease. In certain cases a second breast conserving surgery (BCS) in combination with intraoperative radiotherapy (IORT) is possible. To date, data concerning BCS in combination with IORT in pre-irradiated patients are limited. This is the first pooled analysis of this special indication with a mature follow-up of 5 years. Patients with IBTR after external beam radiotherapy (EBRT; treated in two centers) for breast cancer were included. Patients with previous EBRT including the breast tissue due to other diseases were also included. IORT was performed with the Intrabeam™-device using low kV X-rays. Clinical data including outcome for all patients and toxicity for a representative cohort (LENT-SOMA scales) were obtained. Statistical analyses were done including Kaplan-Meier estimates for local recurrence, distant metastasis and overall survival. A total of 41 patients were identified (39 patients with IBTR, 2 with Hodgkin`s disease in previous medical history). Median follow-up was 58 months (range 4-170). No grade 3/4 acute toxicity occurred within 9 weeks. Local recurrence-free survival rate was 89.9% and overall survival was 82.7% at 5 years. Seven patients developed metastasis within the whole follow-up. BCS in combination with IORT in IBTR in pre-irradiated patients is a feasible method to avoid mastectomy with a low risk of side effects and an excellent local control and good overall survival.

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

Multiple sclerosis, brain radiotherapy, and risk of neurotoxicity: The Mayo Clinic experience

International Nuclear Information System (INIS)

Miller, Robert C.; Lachance, Daniel H.; Lucchinetti, Claudia F.; Keegan, B. Mark; Gavrilova, Ralitza H.; Brown, Paul D.; Weinshenker, Brian G.; Rodriguez, Moses

2006-01-01

Purpose: The aim of this study was a retrospective assessment of neurotoxicity in patients with multiple sclerosis (MS) receiving external beam radiotherapy (EBRT) to the brain. Methods and Materials: We studied 15 consecutively treated patients with MS who received brain EBRT. Neurologic toxicity was assessed with the Common Toxicity Criteria v.3.0. Results: Median follow-up for the 5 living patients was 6.0 years (range, 3.3-27.4 years). No exacerbation of MS occurred in any patient during EBRT. Five patients had Grade 4 neurologic toxicity and 1 had possible Grade 5 toxicity. Kaplan-Meier estimated risk of neurotoxicity greater than Grade 4 at 5 years was 57% (95% confidence interval, 27%-82%). Toxicity occurred at 37.5 to 54.0 Gy at a median of 1.0 year (range, 0.2-4.3 years) after EBRT. Univariate analysis showed an association between opposed-field irradiation of the temporal lobes, central white matter, and brainstem and increased risk of neurotoxicity (p < 0.04). Three of 6 cases of toxicity occurred in patients treated before 1986. Conclusions: External beam radiotherapy of the brain in patients with MS may be associated with an increased risk of neurotoxicity compared with patients without demyelinating illnesses. However, this risk is associated with treatment techniques that may not be comparable to modern, conformal radiotherapy

A simple technique for treating age-related macular degeneration with external beam radiotherapy

International Nuclear Information System (INIS)

Roos, Daniel E.; Francis, J. Winston; Newnham, W. John

1999-01-01

Purpose: To develop a simple external beam photon radiotherapy technique to treat age-related macular degeneration without the need for simulation, planning computed tomography (CT) or computer dosimetry. Methods and Materials: The goal was to enable the treatment to be set up reliably on the treatment machine on Day 1 with the patient supine in a head cast without any prior planning. Using measurements of ocular globe topography from Karlsson et al. (Int J Radiat Oncol Biol Phys 1996; 33: 705-712), we chose a point 1.5 cm behind the anterior surface of the upper eyelid (ASUE) as the isocentre of a half-beam, blocked, 5.0 x 3.0-cm, angled lateral field to treat the involved eye. This would position the isocentre about 0.5 cm behind the posterior surface of the lens, and a little over 1 cm in front of the macula, according to Karlsson et al. The setup requires initial adjustment of the gantry from horizontal (to account for any asymmetry of position of the eyes), then angling 15 deg. posteriorly to avoid the contralateral eye. Finally, the couch is raised to position the isocentre 1.5 cm behind the ASUE. Results: To verify the applicability of the technique, we performed CT and computer dosimetry on the first 11 eyes so treated. Our CT measurements were in good agreement with Karlsson et al. The lens dose was < 5% and the macula was within the 95% isodose curve in each case (6-MV linac). Treatment setup time is approximately 10 min each day. The 11 patients were treated with 5 x 2.00 Gy (2 patients) or 5 x 3.00 Gy (9 patients), and subjective response on follow-up over 1 to 12 months (median 4 months) was comparable to previously reported results, with no significant acute side effects. Conclusion: Our technique is easy to set up and reliably treats the macula, with sparing of the lens and contralateral eye. It enables treatment to commence rapidly and cost-effectively without the need for simulation or CT computer planning

Optical eye tracking system for real-time noninvasive tumor localization in external beam radiotherapy

International Nuclear Information System (INIS)

Via, Riccardo; Fassi, Aurora; Fattori, Giovanni; Fontana, Giulia; Pella, Andrea; Tagaste, Barbara; Ciocca, Mario; Riboldi, Marco; Baroni, Guido; Orecchia, Roberto

2015-01-01

Purpose: External beam radiotherapy currently represents an important therapeutic strategy for the treatment of intraocular tumors. Accurate target localization and efficient compensation of involuntary eye movements are crucial to avoid deviations in dose distribution with respect to the treatment plan. This paper describes an eye tracking system (ETS) based on noninvasive infrared video imaging. The system was designed for capturing the tridimensional (3D) ocular motion and provides an on-line estimation of intraocular lesions position based on a priori knowledge coming from volumetric imaging. Methods: Eye tracking is performed by localizing cornea and pupil centers on stereo images captured by two calibrated video cameras, exploiting eye reflections produced by infrared illumination. Additionally, torsional eye movements are detected by template matching in the iris region of eye images. This information allows estimating the 3D position and orientation of the eye by means of an eye local reference system. By combining ETS measurements with volumetric imaging for treatment planning [computed tomography (CT) and magnetic resonance (MR)], one is able to map the position of the lesion to be treated in local eye coordinates, thus enabling real-time tumor referencing during treatment setup and irradiation. Experimental tests on an eye phantom and seven healthy subjects were performed to assess ETS tracking accuracy. Results: Measurements on phantom showed an overall median accuracy within 0.16 mm and 0.40° for translations and rotations, respectively. Torsional movements were affected by 0.28° median uncertainty. On healthy subjects, the gaze direction error ranged between 0.19° and 0.82° at a median working distance of 29 cm. The median processing time of the eye tracking algorithm was 18.60 ms, thus allowing eye monitoring up to 50 Hz. Conclusions: A noninvasive ETS prototype was designed to perform real-time target localization and eye movement monitoring

External Beam Boost for Cancer of the Cervix Uteri When Intracavitary Therapy Cannot Be Performed

International Nuclear Information System (INIS)

Barraclough, Lisa Helen; Swindell, Ric; Livsey, Jacqueline E.; Hunter, Robin D.; Davidson, Susan E.

2008-01-01

Purpose: To assess the outcome of patients treated with radical radiotherapy for cervical cancer who received an external beam boost, in place of intracavitary brachytherapy (ICT), after irradiation to the whole pelvis. Methods and Materials: Case notes were reviewed for all patients treated in this way in a single center between 1996 and 2004. Patient and tumor details, the reasons why ICT was not possible, and treatment outcome were documented. Results: Forty-four patients were identified. The mean age was 56.4 years (range, 26-88 years). Clinical International Federation of Gynecology and Obstetrics or radiologic stage for Stages I, II, III, and IV, respectively, was 16%, 48%, 27%, and 7%. A total radiation dose of 54-70 Gy was given (75% received ≥60 Gy). Reasons for ICT not being performed were technical limitations in 73%, comorbidity or isolation limitations in 23%, and patient choice in 4%. The median follow-up was 2.3 years. Recurrent disease was seen in 48%, with a median time to recurrence of 2.3 years. Central recurrence was seen in 16 of the 21 patients with recurrent disease. The 5-year overall survival rate was 49.3%. The 3-year cancer-specific survival rate by stage was 100%, 70%, and 42% for Stages I, II, and III, respectively. Late Grades 1 and 2 bowel, bladder, and vaginal toxicity were seen in 41%. Late Grade 3 toxicity was seen in 2%. Conclusion: An external beam boost is a reasonable option after external beam radiotherapy to the pelvis when it is not possible to perform ICT

Modality comparison for small animal radiotherapy: A simulation study

Energy Technology Data Exchange (ETDEWEB)

Bazalova, Magdalena, E-mail: bazalova@stanford.edu; Nelson, Geoff; Noll, John M.; Graves, Edward E. [Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California 94305 (United States)

2014-01-15

Purpose: Small animal radiation therapy has advanced significantly in recent years. Whereas in the past dose was delivered using a single beam and a lead shield for sparing of healthy tissue, conformal doses can be now delivered using more complex dedicated small animal radiotherapy systems with image guidance. The goal of this paper is to investigate dose distributions for three small animal radiation treatment modalities. Methods: This paper presents a comparison of dose distributions generated by the three approaches—a single-field irradiator with a 200 kV beam and no image guidance, a small animal image-guided conformal system based on a modified microCT scanner with a 120 kV beam developed at Stanford University, and a dedicated conformal system, SARRP, using a 220 kV beam developed at Johns Hopkins University. The authors present a comparison of treatment plans for the three modalities using two cases: a mouse with a subcutaneous tumor and a mouse with a spontaneous lung tumor. A 5 Gy target dose was calculated using the EGSnrc Monte Carlo codes. Results: All treatment modalities generated similar dose distributions for the subcutaneous tumor case, with the highest mean dose to the ipsilateral lung and bones in the single-field plan (0.4 and 0.4 Gy) compared to the microCT (0.1 and 0.2 Gy) and SARRP (0.1 and 0.3 Gy) plans. The lung case demonstrated that due to the nine-beam arrangements in the conformal plans, the mean doses to the ipsilateral lung, spinal cord, and bones were significantly lower in the microCT plan (2.0, 0.4, and 1.9 Gy) and the SARRP plan (1.5, 0.5, and 1.8 Gy) than in single-field irradiator plan (4.5, 3.8, and 3.3 Gy). Similarly, the mean doses to the contralateral lung and the heart were lowest in the microCT plan (1.5 and 2.0 Gy), followed by the SARRP plan (1.7 and 2.2 Gy), and they were highest in the single-field plan (2.5 and 2.4 Gy). For both cases, dose uniformity was greatest in the single-field irradiator plan followed by

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

External beam radiotherapy boosted with high dose rate brachytherapy in completely resected uterine sarcomas. Is this a treatment option?

Energy Technology Data Exchange (ETDEWEB)

Pellizzon, Antonio Cassio Assis; Novaes, Paulo Eduardo Ribeiro dos Santos; Maia, Maria Aparecida Conte; Ferrigno, Robson; Fogarolli, Ricardo; Salvajoli, Joao Vitor [Hospital de Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Oncologia de Radiacao]. E-mail: pellizzon@aol.com

2005-04-15

Uterine sarcoma (US) is a relative rare tumor, which accounts for only about 3-5% of all uterine cancers. Aggressive cytoreductive surgery at the time of the initial diagnosis with maximum tumor debulking may lead to a prolonged survival or cure. Objective: to identify and review the role of adjuvant external beam radiation therapy (EBRT) associated with high dose rate brachytherapy (HDRB) in the management of patients presenting US with complete resection. Material and methods: this study is a retrospective analysis of 23 patients with US treated from 10/92 to 03/03, with surgery, external beam radiation therapy (EBRT) and high dose rate brachytherapy (HDRB). The inclusion criteria for study participation included: histologically proven and graded US, completely resection of tumor, Karnofsky status 60-100, absence of significant infection, and recovery from recent surgery. Results: The median age of patients was 62 years (range 39-84); ten-year actuarial disease-free and overall survivals were 42.2% and 63.4%, respectively. On univariate analysis, predictive factors for disease-free survival (DFS) were age at initial presentation (p=0.0268), parity (p=0.0441), tumor grade (p= 0.0095), cervical or vaginal invasion (p=0.0014) and node dissection at time of surgery (p= 0.0471). On multivariate analysis, the only predictive factor was cervical or vaginal invasion (p= 0.048), hazard ratio of 4.7. Conclusion: it is quite likely that neither radiotherapy nor chemotherapy alone will appreciably improve survival in US. If radiation therapy provides better locoregional tumor control, hematogenous metastases will assume an even greater proportion of treatment failures. Unfortunately, our small and heterogeneous group analyzed precludes any definitive conclusions about the impact of HDRB associated to EBRT radiation therapy on recurrence or survival. (author)

External beam radiotherapy boosted with high dose rate brachytherapy in completely resected uterine sarcomas. Is this a treatment option?

International Nuclear Information System (INIS)

Pellizzon, Antonio Cassio Assis; Novaes, Paulo Eduardo Ribeiro dos Santos; Maia, Maria Aparecida Conte; Ferrigno, Robson; Fogarolli, Ricardo; Salvajoli, Joao Vitor

2005-01-01

Uterine sarcoma (US) is a relative rare tumor, which accounts for only about 3-5% of all uterine cancers. Aggressive cytoreductive surgery at the time of the initial diagnosis with maximum tumor debulking may lead to a prolonged survival or cure. Objective: to identify and review the role of adjuvant external beam radiation therapy (EBRT) associated with high dose rate brachytherapy (HDRB) in the management of patients presenting US with complete resection. Material and methods: this study is a retrospective analysis of 23 patients with US treated from 10/92 to 03/03, with surgery, external beam radiation therapy (EBRT) and high dose rate brachytherapy (HDRB). The inclusion criteria for study participation included: histologically proven and graded US, completely resection of tumor, Karnofsky status 60-100, absence of significant infection, and recovery from recent surgery. Results: The median age of patients was 62 years (range 39-84); ten-year actuarial disease-free and overall survivals were 42.2% and 63.4%, respectively. On univariate analysis, predictive factors for disease-free survival (DFS) were age at initial presentation (p=0.0268), parity (p=0.0441), tumor grade (p= 0.0095), cervical or vaginal invasion (p=0.0014) and node dissection at time of surgery (p= 0.0471). On multivariate analysis, the only predictive factor was cervical or vaginal invasion (p= 0.048), hazard ratio of 4.7. Conclusion: it is quite likely that neither radiotherapy nor chemotherapy alone will appreciably improve survival in US. If radiation therapy provides better locoregional tumor control, hematogenous metastases will assume an even greater proportion of treatment failures. Unfortunately, our small and heterogeneous group analyzed precludes any definitive conclusions about the impact of HDRB associated to EBRT radiation therapy on recurrence or survival. (author)

Procedures for the definitive calibration of radiotherapy equipment

International Nuclear Information System (INIS)

1993-01-01

Recommendations from the Institute of Physical Sciences in Medicine are given for the definition calibration of external beam radiotherapy treatment machines and radiation dose measuring equipment used in radiotherapy. (UK)

Conformal radiotherapy for locally advanced juvenile nasopharyngeal angio-fibroma

Directory of Open Access Journals (Sweden)

Supriya Mallick

2015-01-01

Full Text Available Purpose: To assess the efficacy of radiation in the treatment of juvenile nasopharyngeal angiofibroma (JNA. Materials and Methods: Data were retrieved for JNA treated with radiotherapy from 1987-2012. The demographics, treatment and outcome data were recorded in predesigned proforma. Results: Data of 32 patients were retrieved. Median age was 17 years (range: 12-33 years. All patients received radiation because of refractory, residual or unresectable locally advanced disease. All patients were planned with a three-dimensional conformal technique (3DCRT. The median radiation dose was 30 Gray (range: 30-45 Gray. Median follow-up was 129 months (range: 1-276 months. At the last follow-up, 13 patients were found to have a radiological complete response. Two patients progressed 38 and 43 months after completion of treatment and opted for alternative treatment. One patient developed squamous cell carcinoma of the nasal ale 15 years after radiation. Conclusion: Conformal radiotherapy shows promise as an alternative treatment approach for locally advanced JNA and confers long-term disease control with minimal toxicity.

A dosimetric comparison of fan-beam intensity modulated radiotherapy with gamma knife stereotactic radiosurgery for treating intermediate intracranial lesions

International Nuclear Information System (INIS)

Ma Lijun; Xia Ping; Verhey, Lynn J.; Boyer, Arthur L.

1999-01-01

Purpose: To compare and evaluate treatment plans for the fan-beam intensity modulated radiotherapy and the Gamma Knife radiosurgery for treating medium-size intracranial lesions (range 4-25 cm 3 ). Methods and Materials: Treatment plans were developed for the Leksell Gamma Knife and a fan-beam inverse treatment planning system for intensity modulated radiotherapy. Treatment plan comparisons were carried out using dose-volume histogram (DVH), tissue-volume ratio (TVR), and maximum dose to the prescription dose (MDPD) ratio. The study was carried out for both simulated targets and clinical targets with irregular shapes and at different locations. Results: The MDPD ratio was significantly greater for the Gamma Knife plans than for the fan-beam IMRT plans. The Gamma Knife plans produced equivalent TVR values to the fan-beam IMRT plans. Based on the DVH comparison, the fan-beam IMRT delivered significantly more dose to the normal brain tissue than the Gamma Knife. The results of the comparison were found to be insensitive to the target locations. Conclusion: The Gamma Knife is better than the fan-beam IMRT in sparing normal brain tissue while producing equivalent tumor dose conformity for treating medium-size intracranial lesions. However, the target dose homogeneity is significantly better for the fan-beam IMRT than for the Gamma Knife

Organ localization in fractionated external beam radiotherapy for early stage prostatic adenocarcinoma

International Nuclear Information System (INIS)

Jaffray, D.A.; Horwitz, E.M.; Wong, J.W.; Martinez, A.A.; Brabbins, D.S.

1996-01-01

Purpose: Trends toward higher target doses and more conformal radiation field shaping place strict requirements on geometric localisation of the target and surrounding normal structures. Daily localization of these structures is not possible on a conventional treatment machine. For this reason, margins must be incorporated in the field shaping to accommodate any target or normal structure displacement. There are few studies which examine the magnitude of these displacements. We hypothesize that these uncertainties can be reduced by daily radiographic imaging of bony anatomy as an alternative to skin tattoos. This hypothesis is tested using multiple (15-19) CT scans on five patients receiving external beam radiotherapy of the prostate. Materials and Methods: Five patients were CT scanned in treatment position (with immobilization device) on every second day of their initial XRT course (non-boost). Radiopaque markers were placed on the skin tattoos to make them visible in the CT datasets. The scans were collected on a helical CT scanner (SR-7000, 3mm and 5mm slice thickness, 120kVp) and transferred to a workstation for analysis. The structures (prostate, rectum, bladder, and seminal vesicles) on all 80 CT datasets were contoured (manually) by two physicians. A reference dataset was chosen for each patient. The 3D transformations between the study datasets and the reference set were determined using an automated technique. A separate transformation was determined for the alignment of (i) bone (excluding femora) and (ii) skin marks. The contours from each dataset were then transformed back to the reference dataset. The resulting contours show the position of organ relative to either the skin marks (tattoos) or the bony anatomy. The displacement and distortion of the organs were parameterized by the displacement of the volume edge (AP, LAT, SUP-INF), volume, and center-of-mass (COM). Each calculation was performed for an individual patient. Population averages were also

Commissioning and quality assurances of the CMS XIO radiotherapy treatment planning system for external beam photons

International Nuclear Information System (INIS)

Muralidhar, K.R.; Anurupa; Soubhagya; Sudhakar; Shiva; Krishnam Raju, A.; Narayana Murthy, P.

2008-01-01

The commissioning of XIO treatment planning system (TPS) was carried out by Computerized Medical Devices, USA for Siemens and Elekta linear accelerators. The Commissioning and quality assurance of the CMS XIO radiotherapy treatment planning system involves many steps, beginning from beam data acquisition and entry into the computerized TPS, through patient data acquisition, to treatment plan generation and the final transfer of data to the treatment machine and quality assurance of TPS

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)....

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 development of an interdepartmental audit as part of a physics quality assurance programme for external beam therapy

International Nuclear Information System (INIS)

Bonnett, D.E.; Jaukett, R.J.; Mills, J.A.; Martin-Smith, P.

1994-01-01

A cost-effective audit system has been developed that will both detect systematic error in data and procedures, and evaluate the quality assurance programme provided by a physics department for radiotherapy. The audit has been developed for external beam radiotherapy and assesses one modality and one treatment machine per year. The method of assessing the quality assurance programme and the schedule of measurements are described. The process is illustrated using the results of trial audits between the medical physics department at Coventry and Leicester. (author)

Perspectives in absorbed dose metrology with regard to the technical evolutions of external beam radiotherapy

International Nuclear Information System (INIS)

Chauvenet, B.; Bordy, J.M.; Barthe, J.

2009-01-01

This paper presents several R and D axes in absorbed close metrology to meet the needs resulting from the technical evolutions of external beam radiotherapy. The facilities in operation in France have considerably evolved under the impulse of the plan Cancer launched in 2003: replacements and increase of the number of accelerators, substitution of accelerators for telecobalt almost completed and acquisition of innovative facilities for tomo-therapy and stereotaxy. The increasing versatility of facilities makes possible the rapid evolution of treatment modalities, allowing to better delimit irradiation to tumoral tissues and spare surrounding healthy tissues and organs at risk. This leads to a better treatment efficacy through dose escalation. National metrology laboratories must offer responses adapted to the new need, i.e. not restrict themselves to the establishment of references under conventional conditions defined at international level, contribute to the improvement of uncertainties at all levels of reference transfer to practitioners: primary measurements under conditions as close as possible to those of treatment, characterization of transfer and treatment control dosimeters., metrological validation of treatment planning tools... Those axes have been identified as priorities for the next years in ionizing radiation metrology at the European level and included in the European. Metrology Research Programme. A project dealing with some of those topics has been selected in the frame of the Eranet+ Call EMRP 2007 and is now starting. The LNE-LAM is strongly engaged in it. (authors)

The effect of combined external beam and high-dose intracavitary brachytherapy on dysphagia and survival in patients with advanced esophageal cancer

International Nuclear Information System (INIS)

Yorozu, Atsunori; Dokiya, Takushi; Ogita, Mikio; Kutsuki, Shoji

1996-01-01

During an 11-year period, a group of 130 patients with esophageal cancer of stages 2 to 4 were treated with external beam irradiation (40 to 60 Gy) followed by boost dose of 10 to 20 Gy of high-dose intracavitary brachytherapy. The overall 2-year survival rate was 15.4%. The significant prognostic factors were tumor size, response to external beam irradiation, pretreatment dysphagia score, and presence of distant metastases. The palliative effect was excellent; the dysphagia scores of 122 of 130 patients (93.8%) improved. The significant palliative factors were response to external beam irradiation and pretreatment dysphagia score. Tracheoesophageal fistulas developed after treatment in 13 of 130 patients (10%); 3 of the fistulas were probably related to radiotherapy. We conclude that intracavitary brachytherapy is useful in the treatment of cases of advanced cancer which show a good response to external beam irradiation and may be curative in patients with mild dysphagia. (author)

Dosimetric characterization of VIPARnd gel by optical analysis to high-energy photon beam used in external radiotherapy

International Nuclear Information System (INIS)

Dias, Juliana R.; Lima, Renata S.; Lopes, Roseany de V. Vieira; Ceschin, Artemis Marti

2015-01-01

Polymer gel dosimetry has been proposed as a possibility for measurements of dose distribution in radiotherapy. This work aims to evaluate the dosimetric characteristics of a VIPARnd for 6 MV photon beam used in radiotherapy using optical investigations. The absorbance spectrum of irradiated gel dosimeter was optical evaluated with spectrophotometer techniques and with CMOS camera readout for dose range of 0 to 50 Gy. Data shows that the VIPARnd has a maximum absorbance at 300 to 320 nm depending on the absorbed dose. The CMOS camera readouts were obtained in RGB color, the absorbance measurements suggest a major response of dose for blue matrix verified with data. The dose-response curve for blue component showed interval of linearity from 1 Gy to 20 Gy. (author)

MO-A-BRB-03: Integration Issues in Electronic Charting for External Beam Therapy

International Nuclear Information System (INIS)

Sutlief, S.

2015-01-01

The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiation therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy

The feasibility and safety of high-intensity focused ultrasound combined with low-dose external beam radiotherapy as supplemental therapy for advanced prostate cancer following hormonal therapy.

Science.gov (United States)

Wu, Rui-Yi; Wang, Guo-Min; Xu, Lei; Zhang, Bo-Heng; Xu, Ye-Qing; Zeng, Zhao-Chong; Chen, Bing

2011-05-01

The aim of this study was to investigate the feasibility and safety of high-intensity focused ultrasound (HIFU) combined with (+) low-dose external beam radiotherapy (LRT) as supplemental therapy for advanced prostate cancer (PCa) following hormonal therapy (HT). Our definition of HIFU+LRT refers to treating primary tumour lesions with HIFU in place of reduced field boost irradiation to the prostate, while retaining four-field box irradiation to the pelvis in conventional-dose external beam radiotherapy (CRT). We performed a prospective, controlled and non-randomized study on 120 patients with advanced PCa after HT who received HIFU, CRT, HIFU+LRT and HT alone, respectively. CT/MR imaging showed the primary tumours and pelvic lymph node metastases visibly shrank or even disappeared after HIFU+LRT treatment. There were significant differences among four groups with regard to overall survival (OS) and disease-specific survival (DSS) curves (P = 0.018 and 0.015). Further comparison between each pair of groups suggested that the long-term DSS of the HIFU+LRT group was higher than those of the other three groups, but there was no significant difference between the HIFU+LRT group and the CRT group. Multivariable Cox's proportional hazard model showed that both HIFU+LRT and CRT were independently associated with DSS (P = 0.001 and 0.035) and had protective effects with regard to the risk of death. Compared with CRT, HIFU+LRT significantly decreased incidences of radiation-related late gastrointestinal (GI) and genitourinary (GU) toxicity grade ≥ II. In conclusion, long-term survival of patients with advanced PCa benefited from strengthening local control of primary tumour and regional lymph node metastases after HT. As an alternative to CRT, HIFU+LRT showed good efficacy and better safety.

Intraoperative radiotherapy for cancer of the pancreas

International Nuclear Information System (INIS)

Manabe, Tadao; Nagai, Toshihiro; Tobe, Takayoshi; Shibamoto, Yuta; Takahashi, Masaharu; Abe, Mitsuyuki

1985-01-01

Seven patients treated by intraoperative radiotherapy for cancer of the pancreas were evaluated. Three patients undergoing pancreaticoduodenectomy for cancer of the head of the pancreas received a dose of 2,500--3,000 rad (6--10 MeV Betatron) intraoperatively with or without external beam irradiation at a dose of 2,520 rad (10 MeV lineac X-ray). One patient developed radiation pancreatitis and died 0.8 month after surgery. Autopsy revealed the degeneration of cancer cells in the involved superior mesenteric artery. One died of hepatic metastasis 8.5 months after surgery, however, recurrence was not found in the irradiation field. The other patient who had external beam irradiation combined with intraoperative radiotherapy is alive 7.5 months after surgery. Four patients with unresectable cancer of the body of the pancreas received a dose of 2,500--3,000 rad (13--18 MeV Betatron) intraoperatively with or without external beam irradiation at a dose of 1,500--5,520 rad (10 MeV lineac X-ray). One patient died of peritonitis carcinomatosa 3.0 months after surgery. One patient died of DIC 0.6 month after surgery. Two patients are alive 1.0 and 6.5 months after surgery. In these patients with intraoperative radiotherapy for unresectable cancer of the pancreas, remarkable effects on relief of pain and shrinkage of tumor were obtained. Further pursuit of intraoperative and external beam radiotherapies in combination with pancreatectomy should be indicated in an attempt to prolong survival of patient with cancer of the pancreas. (author)

Computer controlled multi-leaf conformation radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Matsuda, T [Tokyo Metropolitan Komagome Hospital (Japan); Inamura, K

1981-10-01

A conformation radiotherapy system with 5-split collimators of which openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator has been developed. Outline of the system performance and its clinical applications are described as follows. 1. Profile of the system: The hardware is composed of three parts, namely, the multi-split collimator, the electronic data processor, and the interface between those two parts. 1) The multi-leaf collimator is composed of 5 pairs (10 leaves) diaphragms. It can be mounted to the X-ray head of a linear accelerator when used, and can be dismounted after its use. 2) The electronic data processor sends control signal to the collimator according to the 5-leaf target volume data which can be stored into a minifloppy disc through the curve digitizer previously. This part is composed of a) dedicated micro processor, b) I/O expansion unit, c) color CRT display with key board, d) dual mini-floppy disc unit, e) curve digitizer and f) digital plotter for recording and verification of resulted accuracy. 2. Performance of the system: 1) Maximum field size: 15 cm x 15 cm at isocenter. 2) Maximum elongation ratio of the target volume: 3 : 1 when the longer diameter is 15 cm. 3) Control accuracy: Within +-3 mm deviation from planned beam focus at isocenter. 3. Clinical application: The method of treatment planning and clinical advantages of this irradiation method are explained by raising clinical experiences such as treating brain tumor and rectal cancer.

Computer controlled multi-leaf conformation radiotherapy

International Nuclear Information System (INIS)

Matsuda, Tadayoshi; Inamura, Kiyonari.

1981-01-01

A conformation radiotherapy system with 5-split collimators of which openings can be controlled symmetrically by computerized techniques during rotational irradiation by a linear accelerator has been developed. Outline of the system performance and its clinical applications are described as follows. 1. Profile of the system: The hardware is composed of three parts, namely, the multi-split collimator, the electronic data processor, and the interface between those two parts. 1) The multi-leaf collimator is composed of 5 pairs (10 leaves) diaphragms. It can be mounted to the X-ray head of a linear accelerator when used, and can be dismounted after its use. 2) The electronic data processor sends control signal to the collimator according to the 5-leaf target volume data which can be stored into a minifloppy disc through the curve digitizer previously. This part is composed of a) dedicated micro processor, b) I/O expansion unit, c) color CRT display with key board, d) dual mini-floppy disc unit, e) curve digitizer and f) digital plotter for recording and verification of resulted accuracy. 2. Performance of the system: 1) Maximum field size: 15 cm x 15 cm at isocenter. 2) Maximum elongation ratio of the target volume: 3 : 1 when the longer diameter is 15 cm. 3) Control accuracy: Within +-3 mm deviation from planned beam focus at isocenter. 3. Clinical application: The method of treatment planning and clinical advantages of this irradiation method are explained by raising clinical experiences such as treating brain tumor and rectal cancer. (author)

Theory, simulation and experiments for precise deflection control of radiotherapy electron beams

Energy Technology Data Exchange (ETDEWEB)

Figueroa, R.; Leiva, J.; Moncada, R.; Rojas, L.; Santibanez, M.; Valente, M.; Young, H. [Universidad de la Frontera, Centro de Fisica e Ingenieria en Medicina, Av. Francisco Salazar 1145, Casilla 54-D, Temuco (Chile); Velasquez, J. [Universidad de la Frontera, Departamento de Ciencias Fisicas, Av. Francisco Salazar 1145, Casilla 54-D, Temuco (Chile); Zelada, G. [Clinica Alemana de Santiago, Av. Vitacura 5951, 13132 Vitacura, Santiago (Chile); Astudillo, R., E-mail: rodolfo.figueroa@ufrontera.cl [Hospital Base de Valdivia, C. Simpson 850, XIV Region de los Rios, Valdivia (Chile)

2017-10-15

Conventional radiotherapy is mainly applied by linear accelerators. Although linear accelerators provide dual (electron/photon) radiation beam modalities, both of them are intrinsically produced by a megavoltage electron current. Modern radiotherapy treatment techniques are based on suitable devices inserted or attached to conventional linear accelerators. Thus, precise control of delivered beam becomes a main key issue. This work presents an integral description of electron beam deflection control as required for novel radiotherapy technique based on convergent photon beam production. Theoretical and Monte Carlo approaches were initially used for designing and optimizing devices components. Then, dedicated instrumentation was developed for experimental verification of electron beam deflection due to the designed magnets. Both Monte Carlo simulations and experimental results support the reliability of electrodynamics models used for predict megavoltage electron beam control. (Author)

Theory, simulation and experiments for precise deflection control of radiotherapy electron beams

International Nuclear Information System (INIS)

Figueroa, R.; Leiva, J.; Moncada, R.; Rojas, L.; Santibanez, M.; Valente, M.; Young, H.; Velasquez, J.; Zelada, G.; Astudillo, R.

2017-10-01

Conventional radiotherapy is mainly applied by linear accelerators. Although linear accelerators provide dual (electron/photon) radiation beam modalities, both of them are intrinsically produced by a megavoltage electron current. Modern radiotherapy treatment techniques are based on suitable devices inserted or attached to conventional linear accelerators. Thus, precise control of delivered beam becomes a main key issue. This work presents an integral description of electron beam deflection control as required for novel radiotherapy technique based on convergent photon beam production. Theoretical and Monte Carlo approaches were initially used for designing and optimizing devices components. Then, dedicated instrumentation was developed for experimental verification of electron beam deflection due to the designed magnets. Both Monte Carlo simulations and experimental results support the reliability of electrodynamics models used for predict megavoltage electron beam control. (Author)

Evaluation of off-axis wedge correction factor using diode dosimeters for estimation of delivered dose in external radiotherapy

International Nuclear Information System (INIS)

Allahverdi, Mahmoud; Shirazi, Alireza; Geraily, Ghazale; Mohammadkarim, Alireza; Esfehani, Mahbod; Nedaie, Hasanali

2012-01-01

An in vivo dosimetry system, using p-type diode dosimeters, was characterized for clinical applications of treatment machines ranging in megavoltage energies. This paper investigates two different models of diodes for externally wedged beams and explains a new algorithm for the calculation of the target dose at various tissue depths in external radiotherapy. The values of off-axis wedge correction factors were determined at two different positions in the wedged (toward the thick and thin edges) and in the non-wedged directions on entrance and exit surfaces of a polystyrene phantom in 60 Co and 6 MV photon beams. Depth transmission was defined on the entrance and exit surfaces to obtain the off-axis wedge correction factor at any depth. As the sensitivity of the diodes depends on physical characteristics (field size, source-skin distance (SSD), thickness, backscatter), correction factors were applied to the diode reading when measuring conditions different from calibration situations. The results indicate that needful correction factors for 60 Co wedged photons are usually larger than those for 6 MV wedged photon beams. In vivo dosimetry performed with the proposed algorithms at externally wedged beams has negligible probable errors (less than 0.5%) and is a reliable method for patient dose control. (author)

Evaluation of off-axis wedge correction factor using diode dosimeters for estimation of delivered dose in external radiotherapy

Directory of Open Access Journals (Sweden)

Mahmoud Allahverdi

2012-01-01

Full Text Available An in vivo dosimetry system, using p-type diode dosimeters, was characterized for clinical applications of treatment machines ranging in megavoltage energies. This paper investigates two different models of diodes for externally wedged beams and explains a new algorithm for the calculation of the target dose at various tissue depths in external radiotherapy. The values of off-axis wedge correction factors were determined at two different positions in the wedged (toward the thick and thin edges and in the non-wedged directions on entrance and exit surfaces of a polystyrene phantom in 60 Co and 6 MV photon beams. Depth transmission was defined on the entrance and exit surfaces to obtain the off-axis wedge correction factor at any depth. As the sensitivity of the diodes depends on physical characteristics [field size, source-skin distance (SSD, thickness, backscatter], correction factors were applied to the diode reading when measuring conditions different from calibration situations . The results indicate that needful correction factors for 60 Co wedged photons are usually larger than those for 6 MV wedged photon beams. In vivo dosimetry performed with the proposed algorithms at externally wedged beams has negligible probable errors (less than 0.5% and is a reliable method for patient dose control.

Erectile function following brachytherapy, external beam radiotherapy, or radical prostatectomy in prostate cancer patients

Energy Technology Data Exchange (ETDEWEB)

Putora, P.M.; Buchauer, K.; Plasswilm, L. [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland); Engeler, D.; Schmid, H.P. [Kantonsspital St. Gallen, Department of Urology, St. Gallen (Switzerland); Haile, S.R.; Graf, N. [Kantonsspital St. Gallen, Clinical Trials Unit, St. Gallen (Switzerland)

2016-03-15

For localized prostate cancer, treatment options include external beam radiotherapy (EBRT), radical prostatectomy (RP), and brachytherapy (BT). Erectile dysfunction (ED) is a common side-effect. Our aim was to evaluate penile erectile function (EF) before and after BT, EBRT, or RP using a validated self-administered quality-of-life survey from a prospective registry. Analysis included 478 patients undergoing RP (n = 252), EBRT (n = 91), and BT (n = 135) with at least 1 year of follow-up and EF documented using IIEF-5 scores at baseline, 6 weeks, 6 months, 1 year, and annually thereafter. Differences among treatments were most pronounced among patients with no or mild initial ED (IIEF-5 ≥ 17). Overall, corrected for baseline EF and age, BT was associated with higher IIEF-5 scores than RP (+ 7.8 IIEF-5 score) or EBRT (+ 3.1 IIEF-5 score). EBRT was associated with better IIEF-5 scores than RP (+ 4.7 IIEF-5 score). In patients undergoing EBRT or RP with bilateral nerve sparing (NS), recovery of EF was observed and during follow-up, the differences to BT were not statistically significant. Overall age had a negative impact on EF preservation (corrected for baseline IIEF). In our series, EF was adversely affected by each treatment modality. Considered overall, BT provided the best EF preservation in comparison to EBRT or RP. (orig.) [German] Die externe Radiotherapie (EBRT), die radikale Prostatektomie (RP) sowie die Brachytherapie (BT) stellen Behandlungsoptionen fuer das lokalisierte Prostatakarzinom dar. Die erektile Dysfunktion (ED) ist eine haeufige Nebenwirkung dieser Therapien. Unser Ziel war es, die penile erektile Funktion (EF) vor und nach BT, EBRT und RP mit Hilfe eines validierten, vom Patienten ausgefuellten Lebensqualitaetsfragebogens aus einer prospektiven Datenbank zu beurteilen. Mit einer minimalen Nachbeobachtungszeit von einem Jahr wurden 478 Patienten analysiert, die eine RP (n = 252), EBRT (n = 91) oder BT (n = 135) erhalten hatten und deren EF mit

Comparative Study of Inguinal Hernia Repair Rates After Radical Prostatectomy or External Beam Radiotherapy

International Nuclear Information System (INIS)

Lughezzani, Giovanni; Sun, Maxine; Perrotte, Paul; Alasker, Ahmed; Jeldres, Claudio; Isbarn, Hendrik; Budaeus, Lars; Lattouf, Jean-Baptiste; Valiquette, Luc; Benard, Francois; Saad, Fred; Graefen, Markus; Montorsi, Francesco; Karakiewicz, Pierre I.

2010-01-01

Purpose: We tested the hypothesis that patients treated for localized prostate cancer with radical prostatectomy (RP) have a higher risk of requiring an inguinal hernia (IH) repair than their counterparts treated with external beam radiotherapy (EBRT). Methods and Materials: Within the Quebec Health Plan database, we identified 6,422 men treated with RP and 4,685 men treated with EBRT for localized prostate cancer between 1990 and 2000, in addition to 6,933 control patients who underwent a prostate biopsy. From among that population, we identified patients who underwent a unilateral or bilateral hernia repair after either RP or EBRT. Kaplan-Meier plots showed IH repair-free survival rates. Univariable and multivariable Cox regression models tested the predictors of IH repair after RP or EBRT. Covariates consisted of age, year of surgery, and Charlson Comorbidity Index. Results: IH repair-free survival rates at 1, 2, 5, and 10 years were 96.8, 94.3, 90.5, and 86.2% vs. 98.9, 98.0, 95.4, and 92.2%, respectively, in RP vs. EBRT patients (log-rank test, p < 0.001). IH repair-free survival rates in the biopsy population were 98.3, 97.1, 94.9, and 90.2% at the same four time points. In multivariable Cox regression models, RP predisposed to a 2.3-fold higher risk of IH repair than EBRT (p < 0.001). Besides therapy type, patient age (p < 0.001) represented the only other independent predictor of IH repair. Conclusions: RP predisposes to a higher rate of IH repair relative to EBRT. This observation should be considered at informed consent.

Successful delivery of adjuvant external beam radiotherapy for ependymoma in a patient with Ondine's curse

International Nuclear Information System (INIS)

Choi, Mehee; Thoma, Miranda; Tolekidis, George; Byrne, Richard W.; Diaz, Aidnag Z.

2015-01-01

Ondine's curse is a rare, potentially life-threatening disorder characterized by loss of automatic breathing during sleep and preserved voluntary breathing. It is seldom encountered in the radiotherapy clinic but can pose significant technical challenges and safety concerns in the delivery of a prescribed radiation course. We report a unique case of successful delivery of radiotherapy for ependymoma in a patient with Ondine's curse. A 53-year-old gentleman presented with vertigo when lying down. Brain magnetic resonance imaging revealed an enhancing mass in the floor of the fourth ventricle. He underwent maximal safe resection. Pathology revealed ependymoma. The patient was referred for radiotherapy. Computed tomography simulation was performed in supine position with 3-point thermoplastic mask immobilization. Sequential TomoTherapy plans were developed. At first scheduled treatment, shortly after mask placement, his arms went limp and he was unresponsive. Vitals showed oxygen saturation 83%, pulse 127, and blood pressure 172/97 mm Hg. He was diagnosed with Ondine's curse thought secondary to previous brainstem damage; the combination of lying flat and pressure from the mask was causing him to go into respiratory arrest. As supine positioning did not seem clinically advisable, he was simulated in prone position. A RapidArc plan and a back-up conformal plan were developed. Prescriptions were modified to meet conservative organs-at-risk constraints. Several strategies were used to minimize uncertainties in set-up reproducibility associated with prone positioning. He tolerated prone RapidArc treatments well. The report highlights the importance of applying practical patient safety and treatment planning/delivery strategies in the management of this challenging case.

External Beam Radiation Therapy for Cancer

Science.gov (United States)

External beam radiation therapy is used to treat many types of cancer. it is a local treatment, where a machine aims radiation at your cancer. Learn more about different types of external beam radiation therapy, and what to expect if you're receiving treatment.

External beam techniques to boost cervical cancer when brachytherapy is not an option—theories and applications

Science.gov (United States)

Kilic, Sarah; Khan, Atif J.; Beriwal, Sushil; Small, William

2017-01-01

The management of locally advanced cervical cancer relies on brachytherapy (BT) as an integral part of the radiotherapy delivery armamentarium. Occasionally, intracavitary BT is neither possible nor available. In these circumstances, post-external beam radiotherapy (EBRT) interstitial brachytherapy and/or hysterectomy may represent viable options that must be adequately executed in a timely manner. However, if these options are not applicable due to patient related or facility related reasons, a formal contingency plan should be in place. Innovative EBRT techniques such as intensity modulated and stereotactic radiotherapy may be considered for patients unable to undergo brachytherapy. Relying on provocative arguments and recent data, this review explores the rationale for and limitations of non-brachytherapy substitutes in that setting aiming to establish a formal process for the optimal execution of this alternative plan. PMID:28603722

Review of common accidents in external beam radiotherapy

International Nuclear Information System (INIS)

Ombogo, C.M

2015-02-01

This work covers patients protection in Radiotherapy which is a multi step procedure that is complex. Any error in any step has an effect on the patient and therefore the entire process requires attention to details in order to achieve patients protection. This project reviews eight case studies involving accidents that occurred during the process of therapy delivery. Professionalism in case one and two was not practiced in that in case one medical physicist failed to calculate decay data instead relied on incorrect decay graph thus giving wrong dose. While in case two a wrong TPS was approved following a formal written procedure due to new technology. In case three and seven there was a software malfunction due to uniformed choice of TPS and in case four a computer file was not updated in the TPS while in eight the failure is inter look system led to patients recieving high dose than was prescribed. Calibration in case five and six was due to wrong actions in both repairs and interpretation of treatment time than the overdose to patient. The lessen learnt seeks to act as a checklist for ensuring patient protection in radiotherapy and prevention of future accidents. (au)

Dosimetric comparison of three-dimensional conformal and intensity modulated radiotherapy in brain glioma

International Nuclear Information System (INIS)

Lu Jie; Zhang Guifang; Bai Tong; Yin Yong; Fan Tingyong; Wu Chaoxia

2009-01-01

Objective: To investigate the dosimetry advantages of intensity modulated radiotherapy (IMRT)of brain glioma compared with that of three-dimensional conformal radiotherapy (SD CRT). Methods: Ten patients with brain glioma were enrolled in this study. Three-dimensional conf0rmal and intensity modulated radiotherapy plans were performed for each patient. The dose distributions of target volume and normal tissues, conformal index (CI) and heterogeneous index (HI) were analyzed using the dose-volume histogram (DVH). The prescription dose was 60 Gy in 30 fractions. Results: IMRT plans decrease the maximum dose and volume of brainstem, mean dose of affected side parotid and maximum dose of spinal-cord. The CI for PTV of IMRT was superior to that of SD CRT, the HI for PTV has no statistical significance of the two model plans. Conclusions: IMRT plans can obviously decrease the dose and volume of brainstem. IMRT is a potential method in the treatment of brain glioma, and dose escalation was possible in patients with brain glioma. (authors)

Conventional (2D) Versus Conformal (3D) Techniques in Radiotherapy for Malignant Pediatric Tumors: Dosimetric Perspectives

International Nuclear Information System (INIS)

Ahmad, N.; Attia, G.; Radwan, A.; El-Badawy, S.; El-Ghoneimy, E.

2009-01-01

Objectives: In pediatric radiotherapy, the enhanced radiosensitivity of the developing tissues combined with the high overall survival, raise the possibility of late complications. The present study aims at comparing two dimensional (2D) and three dimensional (3D) planning regarding dose homogeneity within target volume and dose to organs at risk (OARs) to demonstrate the efficacy of 3D in decreasing dose to normal tissue. Material and Methods: Thirty pediatric patients (18 years or less) with different pediatric tumors were planned using 2D and 3D plans. All were CT scanned after proper positioning and immobilization. Structures were contoured; including the planning target volume (PTV) and organs at risk (OARs). Conformal beams were designed and dose distribution analysis was edited to provide the best dose coverage to the PTV while sparing OARs using dose volume histograms (DVHs) of outlined structures. For the same PTVs conventional plans were created using the conventional simulator data (2-4 coplanar fields). Conventional and 3D plans coverage and distribution were compared using the term of V95% (volume of PTV receiving 95% of the prescribed dose), V107% (volume of PTV receiving 107% of the prescribed dose), and conformity index (CI) (volume receiving 90% of the prescribed dose/PTV). Doses received by OARs were compared in terms of mean dose. In children treated for brain lesions, OAR volume received 90% of the dose (V 90%) and OAR score were calculated. Results: The PTV coverage showed no statistical difference between 2D and 3D radiotherapy in terms of V95% or V107%. However, there was more conformity in 3D planning with CI 1.43 rather than conventional planning with CI 1.86 (p-value <0.001). Regarding OARs, 3D planning shows large gain in healthy tissue sparing. There was no statistical difference in mean dose received by each OAR. However, for brain cases, brain stem mean dose and brain V 90% showed better sparing in 3D planning (brain stem mean dose was

High dose rate interstitial brachytherapy with external beam irradiation for localized prostate cancer. Preliminary results

Energy Technology Data Exchange (ETDEWEB)

Hiratsuka, Junichi; Jo, Yoshimasa; Yoden, Eisaku; Tanaka, Hiroyoshi; Imajo, Yoshinari [Kawasaki Medical School, Kurashiki, Okayama (Japan); Nagase, Naomi; Narihiro, Naomasa; Kubota, Juichi

2000-12-01

This study was undertaken to assess the biochemical and pathological results of combined external beam radiotherapy and high dose rate Ir-192 brachytherapy (HDR-Ir192) for clinically localized prostate cancer. Between October 1997 and August 1999, 39 evaluable patients with adenocarcinoma of prostate diagnosed by biopsy were treated with interstitial and external beam irradiation. Patients ranged in age from 58-82 years, with a mean of 69.7 years. T1c, T2 and T3 tumors, according to the UICC classification system (1997), were found in 7, 21 and 11 cases respectively. The mean initial pre-treatment PSA was 35.9 ng/ml (median 13.2), with 77% of the patients having had a pre-treatment PSA greater than 10 ng/ml. Of all patients, 17 had received pre-treatment hormonal therapy. Hormonal pretreatment was stopped at the beginning of radiotherapy in all cases. External beam four-field box irradiation was given to the small pelvis to a dose of 45 Gy/25 fractions. Three HDR-Ir192 treatments were given over a 30-h period, with 5.5 Gy per fraction at the circumference of the prostate gland over the course of this study. Biochemical failure was defined as a PSA level >1.5 ng/ml and rising on three consecutive values. If serial post-treatment PSA levels showed a continuous downward trend, failure was not scored. The patient with clinical evidence of progression was classified as a clinical failure. The median follow-up at the time of evaluation was 19.6 months. A post-treatment PSA level {<=}1.0 ng/ml was seen in 26 (67%) patients, and values from >1.0 to {<=}2.0 ng/ml were seen in 10 (26%) patients. Biochemical failure was not seen in 38 patients except for one patient who developed a distant bone metastasis with negative prostatic biopsy 15 months after treatment. Biochemical control rate was 100% (38/38) except for the patient with bone metastasis classified as clinical failure. Negative biopsies 18 months after treatment were found in 93% (14/15) of patients. Only one patient

Tolerance and early outcome results of postprostatectomy three-dimensional conformal radiotherapy

International Nuclear Information System (INIS)

Zelefsky, Michael J.; Aschkenasy, Eric; Kelsen, Suzanne; Leibel, Steven A.

1997-01-01

Purpose: Three-dimensional conformal radiotherapy (3D-CRT) has been associated with a reduction in acute and late toxicity among patients treated for localized prostatic cancer. The purpose of this study is to assess the acute and late toxicity of 3D-CRT delivered to patients in the postprostatectomy setting and to analyze which factors predict for durable biochemical control in this group of patients. Methods and Materials: Between 1988 and 1994, 42 patients were treated after prostatectomy with three-dimensional conformal radiotherapy. The median time from prostatectomy to radiotherapy was 11 months. Indications for treatment included a rising serum PSA level in 28 patients (65%) and positive surgical margins without a rising PSA level in 14 (35%). Twenty-five patients (60%) had pathologic stage T3 disease, and 32 (74%) had tumor at or close to the surgical margins. The median dose was 64.8 Gy, and the median follow-up time was 2 years. Results: 3D-CRT in the postprostatectomy setting was well tolerated. Three patients (7%) experienced Grade II acute genitourinary toxicity and nine patients (21%) experienced Grade II acute gastrointestinal toxicity during treatment. No patient experienced Grade III or higher acute morbidity. The 2-year actuarial risk for Grade II late genitourinary and gastrointestinal late complications were 5 and 9%, respectively. In patients with existing incontinence, the incidence of worsening stress incontinence 6 months after treatment was 17%, which resolved within 12 months to its preradiotherapy level in four of six cases (66%). The overall 2-year postirradiation PSA relapse-free survival rate was 53%. The 2-year PSA relapse-free survival was 66% for patients with undetectable PSA levels in the immediate postoperative period compared to 26% for those with detectable levels of PSA after surgery (p 1.0 ng/ml (p 1 ng/ml (p < 0.002) was the most important covariate predicting for a rising PSA after radiotherapy. Conclusions: After

Transitioning from conventional radiotherapy to intensity-modulated radiotherapy for localized prostate cancer. Changing focus from rectal bleeding to detailed quality of life analysis

International Nuclear Information System (INIS)

Yamazaki, Hideya; Nakamura, Satoaki; Nishimura, Takuya; Yoshida, Ken; Yoshioka, Yasuo; Koizumi, Masahiko; Ogawa, Kazuhiko

2014-01-01

With the advent of modern radiation techniques, we have been able to deliver a higher prescribed radiotherapy dose for localized prostate cancer without severe adverse reactions. We reviewed and analyzed the change of toxicity profiles of external beam radiation therapy (EBRT) from the literature. Late rectal bleeding is the main adverse effect, and an incidence of >20% of Grade ≥2 adverse events was reported for 2D conventional radiotherapy of up to 70 Gy. 3D conformal radiation therapy (3D-CRT) was found to reduce the incidence to ∼10%. Furthermore, intensity-modulated radiation therapy (IMRT) reduced it further to a few percentage points. However, simultaneously, urological toxicities were enhanced by dose escalation using highly precise external radiotherapy. We should pay more attention to detailed quality of life (QOL) analysis, not only with respect to rectal bleeding but also other specific symptoms (such as urinary incontinence and impotence), for two reasons: (1) because of the increasing number of patients aged >80 years, and (2) because of improved survival with elevated doses of radiotherapy and/or hormonal therapy; age is an important prognostic factor not only for prostate-specific antigen (PSA) control but also for adverse reactions. Those factors shift the main focus of treatment purpose from survival and avoidance of PSA failure to maintaining good QOL, particularly in older patients. In conclusion, the focus of toxicity analysis after radiotherapy for prostate cancer patients is changing from rectal bleeding to total elaborate quality of life assessment. (author)

A case study of radiotherapy planning for a bilateral metal hip prosthesis prostate cancer patient

International Nuclear Information System (INIS)

Su, Andy; Reft, Chester; Rash, Carla; Price, Jennifer; Jani, Ashesh B.

2005-01-01

The purpose of this report is to communicate the observed advantage of intensity-modulated radiotherapy (IMRT) in a patient with bilateral metallic hip prostheses. In this patient with early-stage low-risk disease, a dose of 74 Gy was planned in two phases-an initial 50 Gy to the prostate and seminal vesicles and an additional 24 Gy to the prostate alone. Each coplanar beam avoided the prosthesis in the beam's eye view. Using the same target expansions for each phase, IMRT and 3D-conformal radiotherapy (CRT) plans were compared for target coverage and inhomogeneity as well as dose to the bladder and rectum. The results of the analysis demonstrated that IMRT provided superior target coverage with reduced dose to normal tissues for both individual phases of the treatment plan as well as for the composite treatment plan. The dose to the rectum was significantly reduced with the IMRT technique, with a composite V80 of 35% for the IMRT plan versus 70% for 3D-CRT plan. Similarly, the dose to the bladder was significantly reduced with a V80 of 9% versus 20%. Overall, various dosimetric parameters revealed the corresponding 3D-CRT plan would not have been acceptable. The results indicate significant success with IMRT in a clinical scenario where there were no curative alternatives for local treatment other than external beam radiotherapy. Therefore, definitive external beam radiation of prostate cancer patients with bilateral prosthesis is made feasible with IMRT. The work described herein may also have applicability to other groups of patients, such as those with gynecological or other pelvic malignancies

Effect of fractionated regional external beam radiotherapy on peripheral blood cell count

International Nuclear Information System (INIS)

Zachariah, B.; Jacob, S.S.; Gwede, C.; Cantor, A.; Patil, J.; Casey, L.; Zachariah, A.B.

2001-01-01

Purpose: The purpose of this study was to assess the need for obtaining weekly complete blood count (CBC) values and to identify the pattern of changes in CBC during regional conventional fractionated radiotherapy. Methods and Materials: A retrospective analysis of CBC data on 299 adult cancer patients who received definitive conventional radiotherapy to head and neck (n=95), chest (n=96), and pelvis (n=108) was performed. Temporal patterns and magnitude of change in white blood cells, neutrophils, lymphocytes, and platelets during radiotherapy were examined. Results: There were statistically significant declines in all counts, albeit not clinically significant. Notable differences between disease sites were found. The greatest weekly interval change in counts occurred during the first week of radiotherapy for all groups of patients. The mean WBC nadir values during treatment were 5.8 for head and neck, 6.8 for chest, and 5.4 for pelvis. The nadirs for all counts occurred toward the middle-to-end of radiotherapy. Lymphocytes were found to be more sensitive to radiotherapy than other leukocyte subcomponents. Conclusion: Our study suggests that weekly CBC monitoring is not necessary for all patients undergoing standard fractionated radiotherapy. Baseline blood counts may be used to determine an optimal schedule for monitoring CBCs in patients receiving conventional radiation alone. Reduced monitoring of CBC may result in significant financial savings

Monte Carlo based simulation of LIAC intraoperative radiotherapy accelerator along with beam shaper applicator

Directory of Open Access Journals (Sweden)

N Heidarloo

2017-08-01

Full Text Available Intraoperative electron radiotherapy is one of the radiotherapy methods that delivers a high single fraction of radiation dose to the patient in one session during the surgery. Beam shaper applicator is one of the applicators that is recently employed with this radiotherapy method. This applicator has a considerable application in treatment of large tumors. In this study, the dosimetric characteristics of the electron beam produced by LIAC intraoperative radiotherapy accelerator in conjunction with this applicator have been evaluated through Monte Carlo simulation by MCNP code. The results showed that the electron beam produced by the beam shaper applicator would have the desirable dosimetric characteristics, so that the mentioned applicator can be considered for clinical purposes. Furthermore, the good agreement between the results of simulation and practical dosimetry, confirms the applicability of Monte Carlo method in determining the dosimetric parameters of electron beam  intraoperative radiotherapy

Perspectives in absorbed dose metrology with regard to the technical evolutions of external beam radiotherapy; Perspectives en metrologie de la dose face aux evolutions techniques de la radiotherapie externe

Energy Technology Data Exchange (ETDEWEB)

Chauvenet, B.; Bordy, J.M. [CEA Saclay, Lab. National Henri Becquerel (LNE-LNHB), 91 - Gif-sur-Yvette (France); Barthe, J. [CEA Saclay (LIST), 91 - Gif-sur-Yvette (France)

2009-07-01

This paper presents several R and D axes in absorbed close metrology to meet the needs resulting from the technical evolutions of external beam radiotherapy. The facilities in operation in France have considerably evolved under the impulse of the plan Cancer launched in 2003: replacements and increase of the number of accelerators, substitution of accelerators for telecobalt almost completed and acquisition of innovative facilities for tomo-therapy and stereotaxy. The increasing versatility of facilities makes possible the rapid evolution of treatment modalities, allowing to better delimit irradiation to tumoral tissues and spare surrounding healthy tissues and organs at risk. This leads to a better treatment efficacy through dose escalation. National metrology laboratories must offer responses adapted to the new need, i.e. not restrict themselves to the establishment of references under conventional conditions defined at international level, contribute to the improvement of uncertainties at all levels of reference transfer to practitioners: primary measurements under conditions as close as possible to those of treatment, characterization of transfer and treatment control dosimeters., metrological validation of treatment planning tools... Those axes have been identified as priorities for the next years in ionizing radiation metrology at the European level and included in the European. Metrology Research Programme. A project dealing with some of those topics has been selected in the frame of the Eranet+ Call EMRP 2007 and is now starting. The LNE-LAM is strongly engaged in it. (authors)

Potential clinical efficacy of intensity-modulated conformal therapy

International Nuclear Information System (INIS)

Meeks, Sanford L.; Buatti, John M.; Bova, Francis J.; Friedman, William A.; Mendenhall, William M.; Zlotecki, Robert A.

1998-01-01

Purpose: The purpose of this study was to examine the potential benefit of using intensity-modulated conformal therapy for a variety of lesions currently treated with stereotactic radiosurgery or conventional radiotherapy. Methods and Materials: Intensity-modulated conformal treatment plans were generated for small intracranial lesions, as well as head and neck, lung, breast, and prostate cases, using the Peacock Plan[reg] treatment-planning system (Nomos Corporation). For small intracranial lesions, intensity-modulated conformal treatment plans were compared with stereotactic radiosurgery treatment plans generated for patient treatment at the University of Florida Shands Cancer Center. For other sites (head and neck, lung, breast, and prostate), plans generated using the Peacock Plan[reg] were compared with conventional treatment plans, as well as beam's-eye-view conformal treatment plans. Plan comparisons were accomplished through conventional qualitative review of two-dimensional (2D) dose distributions in conjunction with quantitative techniques, such as dose-volume histograms, dosimetric statistics, normal tissue complication probabilities, tumor control probabilities, and objective numerical scoring. Results: For small intracranial lesions, there is little difference between intensity-modulated conformal treatment planning and radiosurgery treatment planning in the conformation of high isodose lines with the target volume. However, stereotactic treatment planning provides a steeper dose gradient outside the target volume and, hence, a lower normal tissue toxicity index. For extracranial sites, objective numerical scores for beam's-eye-view and intensity-modulated conformal planning techniques are superior to scores for conventional treatment plans. The beam's-eye-view planning technique prevents geographic target misses and better excludes healthy tissues from the treatment portal. Compared with scores for the beam's-eye-view planning technique, scores for

Proton beam radiotherapy of choroidal melanoma: The Liverpool-Clatterbridge experience

International Nuclear Information System (INIS)

Damato, Bertil; Kacperek, Andrzej; Chopra, Mona; Campbell, Ian R.; Errington, R. Douglas

2005-01-01

Purpose To report on outcomes after proton beam radiotherapy of choroidal melanoma using a 62-MeV cyclotron in patients considered unsuitable for other forms of conservative therapy. Methods and Materials A total of 349 patients with choroidal melanoma referred to the Liverpool Ocular Oncology Centre underwent proton beam radiotherapy at Clatterbridge Centre for Oncology (CCO) between January 1993 and December 2003. Four daily fractions of proton beam radiotherapy were delivered, with a total dose of 53.1 proton Gy, and with lateral and distal safety margins of 2.5 mm. Outcomes measured were local tumor recurrence; ocular conservation; vision; and metastatic death according to age, gender, eye, visual acuity, location of anterior and posterior tumor margins, quadrant, longest basal tumor dimension, tumor height, extraocular extension, and retinal invasion. Results The 5-year actuarial rates were 3.5% for local tumor recurrence, 9.4% for enucleation, 79.1% for conservation of vision of counting fingers or better, 61.1% for conservation of vision of 20/200 or better, 44.8% for conservation of vision of 20/40 or better, and 10.0% for death from metastasis. Conclusion Proton beam radiotherapy with a 62 MeV cyclotron achieves high rates of local tumor control and ocular conservation, with visual outcome depending on tumor size and location

Nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) in pediatric and young adult patients: Results from a prospective study using limited-margin radiotherapy.

Science.gov (United States)

Tinkle, Christopher L; Fernandez-Pineda, Israel; Sykes, April; Lu, Zhaohua; Hua, Chia-Ho; Neel, Michael D; Bahrami, Armita; Shulkin, Barry L; Kaste, Sue C; Pappo, Alberto; Spunt, Sheri L; Krasin, Matthew J

2017-11-15

Indications for and delivery of adjuvant therapies for pediatric nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) have been derived largely from adult studies; therefore, significant concern remains regarding radiation exposure to normal tissue. The authors report long-term treatment outcomes and toxicities for pediatric and young adult patients with high-grade NRSTS who were treated on a prospective trial using limited-margin radiotherapy. Sixty-two patients (ages 3-22 years) with predominantly high-grade NRSTS requiring radiation were treated on a phase 2 institutional study of conformal external-beam radiotherapy and/or brachytherapy using a 1.5-cm to 2-cm anatomically constrained margin. The estimated cumulative incidence of local failure, Gray's method estimated cumulative incidence of local failure, Kaplan-Meier method estimated survival, competing-risk regression model determined predictors of disease outcome, and toxicity was reported according to CTCAE v2.0. At a median follow-up of 5.1 years (range, 0.2-10.9 years), 9 patients had experienced local failure. The 5-year overall cumulative incidence of local failure was 14.8% (95% confidence interval [CI], 7.2%-25%), and all but 1 local failure occurred outside the highest-dose irradiation volume. The 5-year Kaplan-Meier estimates for event-free and overall survival were 49.3% (95% CI, 36.3%-61.1%) and 67.9% (95% CI, 54.2%-78.3%), respectively. Multivariable analysis indicated that younger age was the only independent predictor of local recurrence (P = .004). The 5-year cumulative incidence of grade 3 or 4 late toxicity was 15% (95% CI, 7.2%-25.3%). The delivery of limited-margin radiotherapy using conformal external-beam radiotherapy or brachytherapy provides a high rate of local tumor control without an increase in marginal failures and with acceptable treatment-related morbidity. Cancer 2017;123:4419-29. © 2017 American Cancer Society. © 2017 American Cancer Society.

Estimating the demand for radiotherapy from the evidence: A review of changes from 2003 to 2012

International Nuclear Information System (INIS)

Barton, Michael B.; Jacob, Susannah; Shafiq, Jesmin; Wong, Karen; Thompson, Stephen R.; Hanna, Timothy P.; Delaney, Geoff P.

2014-01-01

Background and Purpose: In 2003 we estimated that 52.3% of new cases of cancer in Australia had an indication for external beam radiotherapy at least once at some time during the course of their illness. This update reviews the contemporary evidence to define the optimal proportion of new cancers that would benefit from radiotherapy as part of their treatment and estimates the changes to the optimal radiotherapy utilisation rate from 2003 to 2012. Materials and Methods: National and international guidelines were reviewed for external beam radiotherapy indications in the management of cancers. Epidemiological data on the proportion of new cases of cancer with each indication for radiotherapy were identified. Indications and epidemiological data were merged to develop an optimal radiotherapy utilisation tree. Univariate and Monte Carlo simulations were used in sensitivity analysis. Results: The overall optimal radiotherapy utilisation rate (external beam radiotherapy) for all registered cancers in Australia changed from 52.3% in 2003 to 48.3% in 2012. Overall 8.9% of all cancer patients in Australia have at least one indication for concurrent chemo-radiotherapy during the course of their illness. Conclusions: The reduction in the radiotherapy utilisation rate was due to changes in epidemiological data, changes to radiotherapy indications and refinements of the model structure

Pilot Quality Control Program for Audit RT External Beams at Mexican Hospitals

International Nuclear Information System (INIS)

Alvarez R, J T; Tovar M, V M

2008-01-01

A pilot quality control program for audit 18 radiotherapy RT external beams at 13 Mexican hospitals is described--for eleven 60 Co beams and seven photon beams of 6, 10 and 15 MV from accelerators. This program contains five parts: a) Preparation of the TLD-100 powder: washing, drying and annealing (one hour 400 deg. C plus 24 hrs 80 deg. C). b) Sending two IAEA type capsules to the hospitals for irradiation at the hospital to a nominal D W = 2 Gy·c) Preparation at the SSDL of ten calibration curves CC in the range of 0.5 Gy to 6 Gy in terms of absorbed dose to water D W for 60 Co with traceability to primary laboratory NRC (Canada), according to a window irradiation: 26/10/2007-7/12/2007. d) Reading all capsules that match their hospital time irradiation and the SSDL window irradiation. f) Evaluation of the Dw imparted by the hospitals

Pilot Quality Control Program for Audit RT External Beams at Mexican Hospitals

Science.gov (United States)

Álvarez R., J. T.; Tovar M., V. M.

2008-08-01

A pilot quality control program for audit 18 radiotherapy RT external beams at 13 Mexican hospitals is described—for eleven 60 Co beams and seven photon beams of 6, 10 and 15 MV from accelerators. This program contains five parts: a) Preparation of the TLD-100 powder: washing, drying and annealing (one hour 400 °C plus 24 hrs 80 °C). b) Sending two IAEA type capsules to the hospitals for irradiation at the hospital to a nominal DW = 2 Gy ṡ c ) Preparation at the SSDL of ten calibration curves CC in the range of 0.5 Gy to 6 Gy in terms of absorbed dose to water DW for 60 Co with traceability to primary laboratory NRC (Canada), according to a window irradiation: 26/10/2007-7/12/2007. d) Reading all capsules that match their hospital time irradiation and the SSDL window irradiation. f) Evaluation of the Dw imparted by the hospitals.

The early toxicity of escalated versus standard dose conformal radiotherapy with neo-adjuvant androgen suppression for patients with localised prostate cancer: Results from the MRC RT01 trial (ISRCTN47772397)

International Nuclear Information System (INIS)

Dearnaley, David P.; Sydes, Matthew R.; Langley, Ruth E.; Graham, John D.; Huddart, Robert A.; Syndikus, Isabel; Matthews, John H.L.; Scrase, Christopher D.; Jose, Chakiath C.; Logue, John; Stephens, Richard J.

2007-01-01

Background: Five-year disease-free survival rates for localised prostate cancer following standard doses of conventional radical external beam radiotherapy are around 80%. Conformal radiotherapy (CFRT) raises the possibility that radiotherapy doses can be increased and long-term efficacy outcomes improved, with safety an important consideration. Methods: MRC RT01 is a randomised controlled trial of 862 men with localised prostate cancer comparing Standard CFRT (64 Gy/32 f) versus Escalated CFRT (74 Gy/37 f), both administered with neo-adjuvant androgen suppression. Early toxicity was measured using physician-reported instruments (RTOG, LENT/SOM, Royal Marsden Scales) and patient-reported questionnaires (MOS SF-36, UCLA Prostate Cancer Index, FACT-P). Results: Overall early radiotherapy toxicity was similar, apart from increased bladder, bowel and sexual toxicity, in the Escalated Group during a short immediate post-radiotherapy period. Toxicity in both groups had abated by week 12. Using RTOG Acute Toxicity scores, cumulative Grade ≥2 bladder and bowel toxicity was 38% and 30% for Standard Group and 39% and 33% in Escalated Group, respectively. Urinary frequency (Royal Marsden Scale) improved in both groups from pre-androgen suppression to 6 months post-radiotherapy (p < 0.001), but bowel and sexual functioning deteriorated. This pattern was supported by patient-completed assessments. Six months after starting radiotherapy the incidence of RTOG Grade ≥2 side-effects was low (<1%); but there were six reports of rectal ulceration (6 Escalated Group), six haematuria (5 Escalated Group) and eight urethral stricture (6 Escalated Group). Conclusions: The two CFRT schedules with neo-adjuvant androgen suppression have broadly similar early toxicity profiles except for the immediate post-RT period. At 6 months and compared to before hormone therapy, bladder symptoms improved, whereas bowel and sexual symptoms worsened. These assessments of early treatment safety will be

Properties of the proton therapy. A high precision radiotherapy

International Nuclear Information System (INIS)

Anon.

2005-01-01

The proton therapy is a radiotherapy using protons beams. The protons present interesting characteristics but they need heavy technologies to be used, such particles accelerators, radiation protection wall and sophisticated technologies to reach the high precision allowed by their ballistic qualities (planning of treatment, beam conformation and patient positioning). (N.C.)

Radiotherapy and skin tumors; Radiotherapie et tumeurs curanees

Energy Technology Data Exchange (ETDEWEB)

Calitchi, E.; KIrova, Y.; Le bourgeois, J.P. [Hopital Henri-Mondor, 94 - Creteil (France)

1998-09-01

Radiotherapy plays an important role in treatment of skin tumours. For skin carcinomas, external irradiation (kilo-voltage X-rays or electrons according to clinical characteristics) is more valuable than interstitial brachytherapy, which is recommended for tumours of the lip and of the nasal vestibule. In mycosis fungoides, total cutaneous electron beam radiation therapy is efficient for patients with limited superficial plaques. In the classical form of Kaposi`s sarcoma, radiotherapy can achieve local control-whereas it obtains good palliative results in the epidemic form. (author)

External audit on the clinical practice and medical decision-making at the departments of radiotherapy in Budapest and Vienna

International Nuclear Information System (INIS)

Esik, O.; Seitz, W.; Loevey, J.; Knocke, T.H.; Gaudi, I.; Nemeth, G.; Poetter, R.

1999-01-01

Purpose: To present an example of how to study and analyze the clinical practice and the quality of medical decision-making under daily routine working conditions in a radiotherapy department, with the aims of detecting deficiencies and improving the quality of patient care.Methods: Two departments, each with a divisional organization structure and an established internal audit system, the University Clinic of Radiotherapy and Radiobiology in Vienna (Austria), and the Department of Radiotherapy at the National Institute of Oncology in Budapest (Hungary), conducted common external audits. The descriptive parameters of the external audit provided information on the auditing (auditor and serial number of the audit), the cohorts (diagnosis, referring institution, serial number and intention of radiotherapy) and the staff responsible for the treatment (division and physician). During the ongoing external audits, the qualifying parameters were (1) the sound foundation of the indication of radiotherapy, (2) conformity to the institution protocol (3), the adequacy of the choice of radiation equipment, (4) the appropriateness of the treatment plan, and the correspondence of the latter with (5) the simulation and (6) verification films. Various degrees of deviation from the treatment principles were defined and scored on the basis of the concept of Horiot et al. (Horiot JC, Schueren van der E, Johansson KA, Bernier J, Bartelink H. The program of quality assurance of the EORTC radiotherapy group. A historical overview. Radiother. Oncol. 1993;29:81-84), with some modifications. The action was regarded as adequate (score 1) in the event of no deviation or only a small deviation with presumably no alteration of the desired end-result of the treatment. A deviation adversely influencing the result of the therapy was considered a major deviation (score 3). Cases involving a minor deviation (score 2) were those only slightly affecting the therapeutic end-results, with effects

External audit on the clinical practice and medical decision-making at the departments of radiotherapy in Budapest and Vienna.

Science.gov (United States)

Esik, O; Seitz, W; Lövey, J; Knocke, T H; Gaudi, I; Németh, G; Pötter, R

1999-04-01

To present an example of how to study and analyze the clinical practice and the quality of medical decision-making under daily routine working conditions in a radiotherapy department, with the aims of detecting deficiencies and improving the quality of patient care. Two departments, each with a divisional organization structure and an established internal audit system, the University Clinic of Radiotherapy and Radiobiology in Vienna (Austria), and the Department of Radiotherapy at the National Institute of Oncology in Budapest (Hungary), conducted common external audits. The descriptive parameters of the external audit provided information on the auditing (auditor and serial number of the audit), the cohorts (diagnosis, referring institution, serial number and intention of radiotherapy) and the staff responsible for the treatment (division and physician). During the ongoing external audits, the qualifying parameters were (1) the sound foundation of the indication of radiotherapy, (2) conformity to the institution protocol (3), the adequacy of the choice of radiation equipment, (4) the appropriateness of the treatment plan, and the correspondence of the latter with (5) the simulation and (6) verification films. Various degrees of deviation from the treatment principles were defined and scored on the basis of the concept of Horiot et al. (Horiot JC, Schueren van der E. Johansson KA, Bernier J, Bartelink H. The program of quality assurance of the EORTC radiotherapy group. A historical overview. Radiother. Oncol. 1993,29:81-84), with some modifications. The action was regarded as adequate (score 1) in the event of no deviation or only a small deviation with presumably no alteration of the desired end-result of the treatment. A deviation adversely influencing the result of the therapy was considered a major deviation (score 3). Cases involving a minor deviation (score 2) were those only slightly affecting the therapeutic end-results, with effects between those of cases

External radiotherapy in macular degeneration: Our technique, dosimetric calculation, and preliminary results

International Nuclear Information System (INIS)

Akmansu, M.; Dirican, Bahar; Oeztuerk, Berrin; Egehan, Ibrahim; Subasi, Mahmut; Or, Meral

1998-01-01

Purpose: This study was performed to determine the toxicity and efficacy of external-beam radiotherapy in patients with age-related subfoveal neovascularization. Methods and Materials: Between January 1996 and September 1996, 25 patients with a mean age of 70.5 (60-84) years were enrolled. All patients underwent fluorescein angiographic evaluation and documentation of their neovascular disease prior to irradiation. A total of 25 patients were treated with a total dose of 12 Gy in 6 fractions over 8 days. We used a lens-sparing technique and patients were treated with a single lateral 6-MV photon beam. To assess the risk of radiation carcinogenesis after treatment of age-related subfoveal neovascularization, we estimated the effective dose for a standard patient on the basis of tissue-weighting factors as defined by the International Commission on Radiological Protection (ICRP). The calculations were made with TLD on a male randophantom. The lens dose was found to be 0.217 Gy per fraction. Results: No significant acute morbidity was noted. Visual acuity was maintained or improved in 76% and 80% of treated patients at their 1- and 3-month follow-up examinations, respectively. On angiographic imaging, there was stabilization of subfoveal neovascular membranes in 23 patients (92%) at 3 months after irradiation. Conclusion: Our observations on these 25 patients in this study indicate that many patients will have improved or stable vision after radiotherapy treatment with low-dose irradiation

Use of External Beam Radiotherapy Is Associated With Reduced Incidence of Second Primary Head and Neck Cancer: A SEER Database Analysis

International Nuclear Information System (INIS)

Rusthoven, Kyle; Chen Changhu; Raben, David; Kavanagh, Brian

2008-01-01

Purpose: Patients with head and neck cancer have a significant risk of developing a second primary cancer of the head and neck. We hypothesized that treatment with external beam radiotherapy (RT) might reduce this risk, because RT can eradicate occult foci of second head and neck cancer (HNCA). Methods and Materials: The data of patients with Surveillance, Epidemiology, and End Results Historic Stage A localized squamous cell carcinoma of the oral cavity, larynx, and pharynx were queried using the Surveillance, Epidemiology, and End Results database. For patients treated with or without RT, the incidence of second HNCA was determined and compared using the log-rank method. Cox proportional hazards analysis was performed for each site, evaluating the influence of covariates on the risk of second HNCA. Results: Between 1973 and 1997, 27,985 patients were entered with localized HNCA. Of these patients, 44% had received RT and 56% had not. The 15-year incidence of second HNCA was 7.7% with RT vs. 10.5% without RT (hazard ratio 0.71, p <0.0001). The effect of RT was more profound in patients diagnosed between 1988 and 1997 (hazard ratio 0.53, p <0.0001) and those with pharynx primaries (hazard ratio 0.47, p <0.0001). On multivariate analysis, RT was associated with a reduced risk of second HNCA for pharynx (p <0.0001) and larynx (p = 0.04) tumors. For oral cavity primaries, RT was associated with an increased risk of second HNCA in patients treated before 1988 (p <0.001), but had no influence on patients treated between 1988 and 1997 (p = 0.91). Conclusion: For localized HNCA, RT is associated with a reduced incidence of second HNCA. These observations are consistent with the eradication of microscopic foci of second HNCA with external beam RT

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

International Nuclear Information System (INIS)

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

2012-01-01

Purpose: To measure the benefits of intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) when used in combination with brachytherapy for the treatment of prostate cancer. Methods and Materials: We conducted a retrospective review of all patients with localized prostate cancer who received external-beam radiotherapy (EBRT) in combination with brachytherapy with at least 1 year follow-up (n = 812). Combination therapy consisted of 103 Pd or 125 I implant, followed by a course of EBRT. From 1993 to March 2003 521 patients were treated with 3D-CRT, and from April 2003 to March 2009 291 patients were treated with IMRT. Urinary symptoms were prospectively measured with the International Prostate Symptom Score questionnaire with a single quality of life (QOL) question; rectal bleeding was assessed per the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The Pearson χ 2 test was used to compare toxicities experienced by patients who were treated with either IMRT or 3D-CRT. Logistic regression analyses were also performed to rule out possible confounding factors. Results: Within the first 3 months after treatment, patients treated with 3D-CRT scored their urinary symptoms as follows: 19% mild, 44% moderate, and 37% severe; patients treated with IMRT scored their urinary symptoms as follows: 36% mild, 47% moderate, and 17% severe (p < 0.001). The 3D-CRT patients rated their QOL as follows: 35% positive, 20% neutral, and 45% negative; IMRT patients rated their QOL as follows: 51% positive, 18% neutral, and 31% negative (p < 0.001). After 1 year of follow-up there was no longer any difference in urinary morbidity between the two groups. Logistic regression confirmed the differences in International Prostate Symptom Score and QOL in the acute setting (p < 0.001 for both). Grade ≥2 rectal bleeding was reported by 11% of 3D-CRT patients and 7

Intensity modulated conformal radiotherapy

International Nuclear Information System (INIS)

Noel, Georges; Moty-Monnereau, Celine; Meyer, Aurelia; David, Pauline; Pages, Frederique; Muller, Felix; Lee-Robin, Sun Hae; David, Denis Jean

2006-12-01

This publication reports the assessment of intensity-modulated conformal radiotherapy (IMCR). This assessment is based on a literature survey which focussed on indications, efficiency and safety on the short term, on the risk of radio-induced cancer on the long term, on the role in the therapeutic strategy, on the conditions of execution, on the impact on morbidity-mortality and life quality, on the impact on the health system and on public health policies and program. This assessment is also based on the opinion of a group of experts regarding the technical benefit of IMCR, its indications depending on the cancer type, safety in terms of radio-induced cancers, and conditions of execution. Before this assessment, the report thus indicates indications for which the use of IMCR can be considered as sufficient or not determined. It also proposes a technical description of IMCR and helical tomo-therapy, discusses the use of this technique for various pathologies or tumours, analyses the present situation of care in France, and comments the identification of this technique in foreign classifications

Patient repositioning in prostate conformal radiotherapy by image fusion

International Nuclear Information System (INIS)

Betrouni, Nacim

2004-01-01

This research thesis first proposes an overview of imaging modalities which are generally used in radiotherapy, and briefly presents operation principles for ultrasound scans, scanners and MRI. The issue of patient repositioning in radiotherapy is then introduced, and already proposed solutions are presented. In the next part, the author addresses space location and ultrasound-based location, with a brief overview of methods used to track the displacements of a mobile object, in this case an ultrasound probe, and calibration. Then, after a presentation of the adopted method, and a discussion of published works related to contour extraction and to filtering and noise reduction methods in ultrasound imagery, the author addresses the issue of prostate segmentation based on ultrasound images. The next part deals with image registration with an overview of available methods and tools. A method of registration of pre-operation images obtained by MRI or scanner, and of intra-operation ultrasound images is proposed for a real-time registration. This method is aimed at supporting patient repositioning during prostate conformal radiotherapy

External quality audits in radiotherapy in Poland

International Nuclear Information System (INIS)

Bulski, W.; Rostkowska, J.; Kania, M.; Gwiazdowska, B.

2002-01-01

The Secondary Standard Dosimetry Laboratory (SSDL) of the Medical Physics Department of the Centre of Oncology in Warsaw is a continuation of the Radiation Measurements Laboratory created in 1937, following the suggestions of Marie Curie, the founder of the Institute. The present SSDL is a member of the WHO/IAEA international network and is periodically audited by the International Atomic Energy Agency. The SSDL is in charge of the calibration of all radiotherapy dosimeters in Poland, and it also co-ordinates all activities carried out in radiotherapy quality assurance programmes nation-wide. The External Audit Group (EAG) was set-up according to the recommendations of the IAEA, as a part of the SSDL. The EAG is in charge of the management of the project and organization of the TLD measurements. The SSDL takes the responsibilities of the metrological aspects of the programme. The results of the efforts, aimed at the development of a quality audit programme and methodology in radiotherapy, are presented

Optimum location of external markers using feature selection algorithms for real‐time tumor tracking in external‐beam radiotherapy: a virtual phantom study

Science.gov (United States)

Nankali, Saber; Miandoab, Payam Samadi; Baghizadeh, Amin

2016-01-01

In external‐beam radiotherapy, using external markers is one of the most reliable tools to predict tumor position, in clinical applications. The main challenge in this approach is tumor motion tracking with highest accuracy that depends heavily on external markers location, and this issue is the objective of this study. Four commercially available feature selection algorithms entitled 1) Correlation‐based Feature Selection, 2) Classifier, 3) Principal Components, and 4) Relief were proposed to find optimum location of external markers in combination with two “Genetic” and “Ranker” searching procedures. The performance of these algorithms has been evaluated using four‐dimensional extended cardiac‐torso anthropomorphic phantom. Six tumors in lung, three tumors in liver, and 49 points on the thorax surface were taken into account to simulate internal and external motions, respectively. The root mean square error of an adaptive neuro‐fuzzy inference system (ANFIS) as prediction model was considered as metric for quantitatively evaluating the performance of proposed feature selection algorithms. To do this, the thorax surface region was divided into nine smaller segments and predefined tumors motion was predicted by ANFIS using external motion data of given markers at each small segment, separately. Our comparative results showed that all feature selection algorithms can reasonably select specific external markers from those segments where the root mean square error of the ANFIS model is minimum. Moreover, the performance accuracy of proposed feature selection algorithms was compared, separately. For this, each tumor motion was predicted using motion data of those external markers selected by each feature selection algorithm. Duncan statistical test, followed by F‐test, on final results reflected that all proposed feature selection algorithms have the same performance accuracy for lung tumors. But for liver tumors, a correlation‐based feature

Combined modality therapy for localized prostate carcinoma using Iridium-192 brachytherapy and external beam radiotherapy: results, morbidity, and the lack of value of surgical lymph node staging

International Nuclear Information System (INIS)

Baird, Michael; Ordorica, Edward; Dawson, Anne

1997-01-01

Purpose/Objective: (1) To quantitate the morbidity and 5 and 10 year bNED survival of Ir-192 temporary implant combined with external beam radiotherapy in the treatment of clinically localized Prostate Carcinoma. (2) To determine the need for nodal staging prior to implant. Materials and Methods: 335 consecutively treated patients seen between 8/17/84 and 8/13/93 were analyzed. All patents had retropertoneal nodal dissection and were implanted with Ir-192 using the Syed-Neblett template. Thirteen percent who completed treatment per protocol were found to have microscopically involved nodes on permanent section. 277 patients had completed the entire treatment protocol and had at least 2 years follow-up with DRE and serial serum PSAs. All patients were evaluated for morbidity using the standard RTOG morbidity scales. The bNED survival was determined using Kaplan-Meier methods with a non-rising PSA value of < 1.0 used as an indicator of disease control. All patients received 30 Gy in 50 hrs. to the implant volume, followed in two weeks by 34.2 Gy external beam (19 fx/ 25 days). The median follow up for the group is 55 months. Results: Morbidity: 69.2% of the patients experienced no reportable morbidity. Urinary morbidity was usually transient and mild (Grade 1 or 2 in 9.7%). 4.9 % experienced grade 3 urinary complaints (6.6% stress incontinence) and the incidence of grade 4 urinary complaints was 0.6%. Urinary complications were 2.5 times more common in patients who had previously undergone a TURP. Rectal complications were mild or moderate in 10.5% and usually consisted of asymptomatic rectal bleeding (6.9%). Severe rectal ulcer requiring temporary colostomy occurred in 1.4% and always healed after colostomy. Other morbidity consisted of mild, self-limited edema (2.1%). One patient had persistent edema post treatment, and there was one death from a CVA perioperatively (0.3%). 75% of patients who were potent prior to treatment maintained useful sexual function post

Leaflet manual of external beam radiation therapy for hepatocellular carcinoma: a review of the indications, evidences, and clinical trials

Directory of Open Access Journals (Sweden)

Rim CH

2018-05-01

Full Text Available Chai Hong Rim, Won Sup Yoon Department of Radiation Oncology, Ansan Hospital, Korea University Medical College, Ansan, Republic of Korea Abstract: The use of external beam radiation therapy (EBRT in the treatment of hepatocellular carcinoma (HCC, which was rarely performed due to liver toxicity with a previous technique, has increased. Palliation of portal vein thrombosis, supplementation for insufficient transarterial chemoembolization, and provision of new curative opportunities using stereotactic body radiotherapy are the potential indications for use of EBRT. The mechanism of EBRT treatment, with its radiobiological and physical perspectives, differs from those of conventional medical treatment or surgery. Therefore, understanding the effects of EBRT may be unfamiliar to physicians other than radiation oncologists, especially in the field of HCC, where EBRT has recently begun to be applied. The first objective of this review was to concisely explain the indications for use of EBRT for HCC for all physicians treating HCC. Therefore, this review focuses on the therapeutic outcomes rather than the detailed biological and physical background. We also reviewed recent clinical trials that may extend the indications for use of EBRT. Finally, we reviewed the current clinical practice guidelines for the treatment of HCC and discuss the current recommendations and future perspectives. Keywords: hepatocellular carcinoma, liver neoplasm, external beam radiotherapy, stereotactic body radiotherapy, clinical trials, sorafenib, guidelines

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

Energy Technology Data Exchange (ETDEWEB)

Dickie, Colleen I., E-mail: Colleen.dickie@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); Griffin, Anthony M. [Division of Orthopaedic Surgery, University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto (Canada); University of Toronto, Toronto (Canada); Parent, Amy L. [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); Chung, Peter W.M.; Catton, Charles N. [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); University of Toronto, Toronto (Canada); Svensson, Jon [AngliaRuskin University, Cambridge (United Kingdom); Ferguson, Peter C.; Wunder, Jay S.; Bell, Robert S. [Division of Orthopaedic Surgery, University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto (Canada); University of Toronto, Toronto (Canada); Sharpe, Michael B.; O' Sullivan, Brian [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); University of Toronto, Toronto (Canada)

2012-03-15

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Intraoperative electron beam radiation therapy (IOEBRT) for carcinoma of the exocrine pancreas

International Nuclear Information System (INIS)

Dobelbower, R.R. Jr.; Konski, A.A.; Merrick, H.W. III; Bronn, D.G.; Schifeling, D.; Kamen, C.

1991-01-01

The abdominal cavities of 50 patients were explored in a specially constructed intraoperative radiotherapy operating amphitheater at the Medical College of Ohio. Twenty-six patients were treated with intraoperative and postoperative precision high dose external beam therapy, 12 with intraoperative irradiation but no external beam therapy, and 12 with palliative surgery alone. All but two patients completed the postoperative external beam radiation therapy as initially prescribed. The median survival time for patients treated with palliative surgery alone was 4 months, and that for patients treated with intraoperative radiotherapy without external beam therapy was 3.5 months. Patients undergoing intraoperative irradiation and external beam radiation therapy had a median survival time of 10.5 months. Four patients died within 30 days of surgery and two patients died of gastrointestinal hemorrhage 5 months posttreatment

Acute skin toxicity-related, out-of-pocket expenses in patients with breast cancer treated with external beam radiotherapy: a descriptive, exploratory study.

Science.gov (United States)

Schnur, Julie B; Graff Zivin, Joshua; Mattson, David M K; Green, Sheryl; Jandorf, Lina H; Wernicke, A Gabriella; Montgomery, Guy H

2012-12-01

Acute skin toxicity is one of the most common side effects of breast cancer radiotherapy. To date, no one has estimated the nonmedical out-of-pocket expenses associated with this side effect. The primary aim of the present descriptive, exploratory study was to assess the feasibility of a newly developed skin toxicity costs questionnaire. The secondary aims were to: (1) estimate nonmedical out-of-pocket costs, (2) examine the nature of the costs, (3) explore potential background predictors of costs, and (4) explore the relationship between patient-reported dermatologic quality of life and expenditures. A total of 50 patients (mean age = 54.88, Stage 0-III) undergoing external beam radiotherapy completed a demographics/medical history questionnaire as well as a seven-item Skin Toxicity Costs (STC) questionnaire and the Skindex-16 in week 5 of treatment. Mean skin toxicity costs were $131.64 (standard error [SE] = $23.68). Most frequently incurred expenditures were new undergarments and products to manage toxicity. Education was a significant unique predictor of spending, with more educated women spending more money. Greater functioning impairment was associated with greater costs. The STC proved to be a practical, brief measure which successfully indicated specific areas of patient expenditures and need. Results reveal the nonmedical, out-of-pocket costs associated with acute skin toxicity in the context of breast cancer radiotherapy. To our knowledge, this study is the first to quantify individual costs associated with this treatment side effect, as well as the first to present a scale specifically designed to assess such costs. In future research, the STC could be used as an outcome variable in skin toxicity prevention and control research, as a behavioral indicator of symptom burden, or as part of a needs assessment.

Results of three-dimensional conformal radiotherapy and thalidomide for advanced hepatocellular carcinoma

International Nuclear Information System (INIS)

Hsu, Wei-Chung; Chung, Na-Na; Wang, Po-Ming; Ying, Kung-Shih; Shin, Jeng-Shiann; Chao, Che-Jen; Lin, Gau-De; Chan, Sue-Ching; Ting, Lai-Lei

2006-01-01

The purpose of this study was to evaluate the effectiveness of three-dimensional conformal radiotherapy and thalidomide in the treatment of advanced hepatocellular carcinoma. Between 1999 and 2003, 121 patients (mean age, 54.4±12.4 years; range, 20-81 years) with advanced hepatocellular carcinoma received three-dimensional conformal radiotherapy and thalidomide. Radiation was delivered in 1.5 Gy fractions twice daily for 5 days a week, for a total dose of 45-75 Gy. Mean treatment volume was 429.52±408.50 cm 3 (range, 26.89-2284.82 cm 3 ). Thalidomide was given concomitantly: 200 mg/day in 109 patients, 300 mg/day in 8 patients and 400 mg/day in 4 patients. Treatment responses, survival rates and factors affecting survival were analyzed. Treatment responses were observed in 61% of the patients. Liver cirrhosis (P=0.001) and tumor size (P=0.001) significantly affected the tumor responses. Overall survival at 6, 12 and 24 months was 84.8, 60.0 and 44.6%, respectively. On univariate analysis, liver cirrhosis (P=0.003), Karnofsky performance status (P=0.007), tumor size (P<0.001), portal vein tumor thrombosis (P<0.001) and alpha-fetoprotein level (P=0.003) were shown to significantly affect survival. On multivariate analysis, only thrombosis (P=0.039) and alpha-fetoprotein level (P=0.006) were shown to be factors affecting survival. Three-dimensional conformal radiotherapy with thalidomide seems to be effective in the treatment of advanced hepatocellular carcinoma. (author)

Defining a dose-response relationship for prostate external beam radiotherapy

International Nuclear Information System (INIS)

Trada, Yuvnik; Plank, Ash; Martin, Jarad

2013-01-01

We aimed to quantify a relationship between radiotherapy dose and freedom from biochemical failure (FFBF) in low- and intermediate-risk prostate cancer. To reduce confounding we used data with a standardised end–point, mature follow-up, low competing risk of metastatic failure, conventional fractionation and separate reporting for outcomes with hormonal therapy (HT). A systematic review of the literature was carried out. Studies that reported the use of radiotherapy alone in 1.8–2Gy fractions in low- and intermediate-risk prostate cancer were included. The primary end–point was Phoenix definition 5-year FFBF. A logistic regression was used to quantify the dose–response relationship. Data from eight studies with 3037 patients met the inclusion criteria. The data from 810 low-risk patients and 2245 intermediate-risk patients were analysed. A strong association between radiotherapy dose and FFBF was found in low- and intermediate-risk patients managed with radiotherapy alone. In low-risk patients not treated with HT the dose required to achieve 50% biochemical tumour control (TCD 50 ) is 52.0 Gy and the slope of the dose–response curve at TCD 50 (γ 50 ) is 2.1%/Gy. At 78Gy this represented a FFBF of 90.3%. In intermediate-risk patients not treated with HT the TCD 50 is 64.7Gy and γ 50 is 3.2%/Gy. At 78 Gy this translated into a FFBF of 84.3%. HT had a small effect for low-risk patients and an inconsistent effect for intermediate-risk men. A strong association was found between radiation dose and biochemical outcome in both low- and intermediate-risk patients. Standardised reporting of results from future studies will make future analyses more robust.

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.)

Beam-beam effects under the influence of external noise

International Nuclear Information System (INIS)

Ohmi, K

2014-01-01

Fast external noise, which gives fluctuation into the beam orbit, is discussed in connection with beam-beam effects. Phase noise from crab cavities and detection devices (position monitor) and kicker noise from the bunch by bunch feedback system are the sources. Beam-beam collisions with fast orbit fluctuations with turn by turn or multi-turn correlations, cause emittance growth and luminosity degradation. We discuss the tolerance of the noise amplitude for LHC and HL-LHC

Nasopharynx carcinoma treatment: from the conventional radiotherapy to the conformal radiotherapy with intensity modulation; Traitement du carcinome du nasopharynx: de la radiotherapie conventionnelle a la radiotherapie conformationnelle avec modulation d'intensite

Energy Technology Data Exchange (ETDEWEB)

Mokaouim, K.; Grehange, G.; Truc, G.; Peingnaux, K.; Martin, E.; Zanetta, S.; Bruchon, Y.; Bonnetain, F.; Maingon, P. [Centre Georges-Francois Leclerc, 21 - Dijon (France)

2009-10-15

The objective of this study was to evaluate retrospectively the impact of factors linked to the radiotherapy realisation on the local and locoregional control, the global survival, the survival without disease of patients suffering of naso-pharynx carcinoma. Conclusion: the patients suffering of a nasopharynx carcinoma treated by irradiation associated to chemotherapy have an improved global survival and an improved survival without disease. The conformal radiotherapy with or without modulated intensity reduce the risk of serous otitis, trismus and xerostomia at long term. It seems necessary to realize multi centric studies with a longer period of follow up before asserting the advantages of the I.M.R.T. in comparison to the classical and conformal technique in the treatment of naso-pharynx carcinomas. (N.C.)

Low morbidity following 9,000-rad intracavitary endocurietherapy (ECT) using the Kumar cervical applicator and external-beam radiotherapy (EXRT) in the management of carcinoma of the uterine cervix

International Nuclear Information System (INIS)

Kumar, P.P.; Good, R.R.; Scott, J.C.; Jones, E.O.; Lynch, G.; McCaul, G.F.

1988-01-01

The Kumar Cervical Applicator minimizes patient discomfort and improves patient mobility while reducing the tendency of the applicator to rotate during the 40 to 50 hours of uterine intracavitary endocurietherapy. Patients with previously untreated invasive carcinoma of the uterine cervix, F.I.G.O. stages IB-IVA, were treated with two Kumar intracavitary endocurietherapy (ECT) applications of 2,500 rad each to point ''A,'' and 4,000 rad external-beam radiotherapy (EXRT) to midplane, for a total dose of 9,000 rad. The major complication rate was 2.7 %, and the local control rate was 85 % (22/26 patients) for stage I and II, and 91 % (10/11 patients) for stage III and IVA. (author)

Microplanar beams for radiotherapy

International Nuclear Information System (INIS)

Company, F.Z.; Allen, B.J.

1996-01-01

Recent advances in synchrotron generated X-ray beams with high fluence rate permit the investigation of the application of an array of closely spaced, parallel or converging microbeams in radiotherapy. The proposed technique takes advantage of the hypothesised repair mechanism of capillary cells between alternate microbeam zones, which replaces the lethally irradiated endothelial cells. In this study using the Monte Carlo method, the lateral and depth dose of a single planar microbeam of 100 keV in a tissue/lung/tissue phantom is investigated. Poster 195. (author)

WE-G-BRE-06: New Potential for Enhancing External Beam Radiotherapy for Lung Cancer Using FDA-Approved Concentrations of Cisplatin Or Carboplatin Nanoparticles Administered Via Inhalation

International Nuclear Information System (INIS)

Hao, Y; Altundal, Y; Sajo, E; Detappe, A; Makrigiorgos, G; Berbeco, R; Ngwa, W

2014-01-01

Purpose: This study investigates, for the first time, the dose enhancement to lung tumors due to cisplatin nanoparticles (CNPs) and carboplatin nanoparticles (CBNPs) administered via inhalation route (IR) during external beam radiotherapy. Methods: Using Monte Carlo generated 6 MV energy fluence spectra, a previously employed analytic method was used to estimate dose enhancement to lung tumor due to radiation-induced photoelectrons from CNPs administered via IR in comparison to intravenous (IV) administration. Previous studies have indicated about 5% of FDA-approved cisplatin concentrations reach the lung tumor via IV. Meanwhile recent experimental studies indicate that 3.5–14.6 times higher concentrations of CNPs can reach the lung tumors by IR compared to IV. Taking these into account, the dose enhancement factor (DEF) defined as the ratio of the dose with and without CNPs was calculated for field size of 10 cm × 10 cm (sweeping gap), for a range of tumor depths and tumor sizes. Similar calculations were done for CBNPs. Results: For IR with 3.5 times higher concentrations than IV, and 2 cm diameter tumor, clinically significant DEF values of 1.19–1.30 were obtained for CNPs at 3–10 cm depth, respectively, in comparison to 1.06–1.09 for IV. For CBNPs, DEF values of 1.26–1.41 were obtained in comparison to 1.07–1.12 for IV. For IR with 14.6 times higher concentrations, higher DEF values were obtained e.g. 1.81–2.27 for CNPs. DEF increased with increasing field size or decreasing tumor size. Conclusions: Our preliminary results indicate that major dose enhancement to lung tumors can be achieved using CNPs/CBNPs administered via IR, in contrast to IV administration during external beam radiotherapy. These findings highlight a potential new approach for radiation boosting to lung tumors using CNPs/CBNPs administered via IR. This would, especially, be applicable during concomitant chemoradiotherapy, potentially allowing for dose enhancement while

Practical recommendations for breathing-adapted radiotherapy; Bonnes pratiques pour la radiotherapie asservie a la respiration

Energy Technology Data Exchange (ETDEWEB)

Simon, L.; Giraud, P.; Rosenwald, J.C. [Institut Curie, Dept. d' Oncologie-radiotherapie, 75 - Paris (France); Dumas, J.L.; Lorchel, F. [CHU de Besancon, Hopital Jean-Minjoz, Service Radiotherapie, 25 - Besancon (France); Marre, D. [Institut Claudius-Regaud, Dept. des Radiations, 31 - Toulouse (France); Dupont, S. [Hopital Europeen Georges-Pompidou, Service d' Oncoradiotherapie, 75 - Paris (France); Varmenot, N. [Centre Henri-Becquerel, UnitE de Physique Medicale, 76 - Rouen (France); Ginestet, C. [Centre Leon-Berard, Dept. de Radiotherapie, 69 - Lyon (France); Caron, J. [Institut Bergonie, Dept. de Radiotherapie, 33 - Bordeaux (France); Marchesi, V. [Centre Alexis-Vautrin, Dept. de Radiotherapie, 54 - Vandoeuvre-les-Nancy (France); Ferreira, I. [Institut Gustave-Roussy, Dept. d' Oncologie Radiotherapie, 94 - Villejuif (France); Garcia, R. [Institut Sainte-Catherine, Service de Radiotherapie, 84 - Avignon (France)

2007-06-15

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience. (authors)

Assessment of radiotherapy photon beams: A practical and low cost methodology

International Nuclear Information System (INIS)

Reis, C.Q.M.; Nicolucci, P.

2017-01-01

Dosimetric properties of radiation beams used in radiotherapy are directly related to the energy spectrum produced by the treatment unit. Therefore, the development of methodologies to evaluate in a simple and accurate way the spectra of clinical beams can help establishing the quality control of the treatment. The purpose of this study is to present a practical and low cost methodology for determining primary spectra of radiotherapy photon beams from transmission measurements in attenuators of aluminum and using the method of the inverse Laplace transform. Monte Carlo simulation with PENELOPE code was used in order to evaluate and validate the reconstructed spectra by the calculation of dosimetric parameters that characterize the beam. Percentage depth dose values simulated with a 6 MV reconstructed spectrum shows maximum difference of 4.4% when compared to values measured at the corresponding clinical beam. For a 10 MV beam that difference was around 4.2%. Results obtained in this study confirm the adequacy of the proposed methodology for assessing primary photon beams produced by clinical accelerators. - Highlights: • Primary spectra of radiotherapy photon beams are determined from transmission measurements. • Monte Carlo calculations are used to evaluate the method of the inverse Laplace transform. • The proposed methodology is practical and of low cost for clinical purposes. • Results are in fair agreement with literature and clinical data.

External beam radiotherapy facilities in Ukraine. Trends and challenges

International Nuclear Information System (INIS)

Starenkiy, V.P.; Petrichenko, O.O.; Averyanova, L.O.

2017-01-01

The most important aspects of technological support of the radiation therapy of Ukraine are considered in accordance with the requirements of the IAEA. The reasons that influence the availability of radiotherapy for cancer patients in Ukraine are analyzed taking into account the experience of Grigoriev Institute for Medical Radiology of the National Academy of Medical Sciences of Ukraine.

125I implants as an adjuvant to surgery and external beam radiotherapy in the management of locally advanced head and neck cancer

International Nuclear Information System (INIS)

Martinez, A.; Goffinet, D.R.; Fee, W.; Goode, R.; Cox, R.S.

1983-01-01

125 I seeds either individually placed or inserted into absorbable Vicryl suture carriers were utilized in conjunction with surgery and external beam radiotherapy in an attempt to increase local control rates in patients with advanced oropharyngeal and laryngopharyngeal cancers (T3-T4, N2-N3), massive cervical lymphadenopathy (N3) and an unknown primary site and locally recurrent head and neck cancers. Forty-eight patients were treated with 55 implants. The carotid artery was implanted in 15 patients, while seven patients had seeds inserted into the base of the skull region, and another three patients had implants near cranial nerves. Eighteen of the 48 patients were treated for cure. The actuarial survival at five years in this subgroup was 50%. The overall local control in the head and neck area was 58%. In this group no patients to date have had a local failure in the implanted volume. Seventeen patients with comparable stage of disease treated prior to 1974 with curative intent without 125 I implants were analyzed retrospectively for comparison with the implanted patients. The actuarial survival of these patients was 18% and the overall head and neck control was 21%. These differences are statistically significant at a P value of 0.01 and 0.007, respectively. Seventeen patients received implants for local recurrence. The local control in the head and neck area was 50%; however, the 2.5 year actuarial survival was only 17%. The complication rate was 11% (six of 55 implants). The improved survival, the high local control, and the minimal complication rates in this series makes the intraoperative implantation of 125 I seeds and effective adjunctive treatment to surgery and external beam irradiation

Conformity index: A review

International Nuclear Information System (INIS)

Feuvret, Loic; Noel, Georges; Mazeron, Jean-Jacques; Bey, Pierre

2006-01-01

We present a critical analysis of the conformity indices described in the literature and an evaluation of their field of application. Three-dimensional conformal radiotherapy, with or without intensity modulation, is based on medical imaging techniques, three-dimensional dosimetry software, compression accessories, and verification procedures. It consists of delineating target volumes and critical healthy tissues to select the best combination of beams. This approach allows better adaptation of the isodose to the tumor volume, while limiting irradiation of healthy tissues. Tools must be developed to evaluate the quality of proposed treatment plans. Dosimetry software provides the dose distribution in each CT section and dose-volume histograms without really indicating the degree of conformity. The conformity index is a complementary tool that attributes a score to a treatment plan or that can compare several treatment plans for the same patient. The future of conformal index in everyday practice therefore remains unclear

External beam radiation for retinoblastoma: Results, patterns of failure, and a proposal for treatment guidelines

International Nuclear Information System (INIS)

Hernandez, J. Carlos; Brady, Luther W.; Shields, Jerry A.; Shields, Carol L.; Potter, Patrick de; Karlsson, Ulf L.; Markoe, Arnold M.; Amendola, Beatriz E.; Singh, Arun

1996-01-01

Purpose: To analyze treatment results and patterns of failure following external beam radiation for retinoblastoma and propose treatment guidelines according to specific clinical variables. Methods and Materials: We analyzed 27 patients (34 eyes) with retinoblastoma who received external beam radiation as initial treatment at Hahnemann University Hospital from October 1980 to December 1991 and have been followed for at least 1 year. Of the 34 eyes, 14 were Groups I-II (Reese-Ellsworth classification), 7 were Group III, and 13 were Groups IV-V. Doses ranged from 34.5-49.5 Gy (mean 44.3 Gy, median 45 Gy) in 1.5-2.0 Gy fractions generally delivered through anterior and lateral wedged pair fields. Results: At a mean follow up of 35.2 months (range 12-93 months), local tumor control was obtained in 44% (15 out of 34) of eyes with external beam radiation alone. Salvage therapy (plaque brachytherapy, cryotherapy, and/or photocoagulation) controlled an additional 10 eyes (29.5%), so that overall ocular survival has been 73.5%. Local tumor control with external beam radiotherapy alone was obtained in 78.5% (11 out of 14) of eyes in Groups I-II, but in only 20% (4 out of 20) of eyes in Groups III-V. A total of 67 existing tumors were identified prior to treatment in the 34 treated eyes and local control with external beam radiation alone was obtained in 87% (46 out of 53) of tumors measuring 15 mm or less and in 50% (7 out of 14) of tumors measuring more than 15 mm. When analyzing patterns of failure in the 19 eyes that relapsed, a total of 28 failure sites were identified and consisted of progression of vitreous seeds in seven instances (25% of failure sites) recurrences from previously existing tumors in 10 instances (36% of failure sites) and development of new tumors in previously uninvolved retina in 11 instances (39% of failure sites). Conclusions: 1) We find that external beam radiation to a dose of 45 Gy in fractions of 1.5 to 2.0 Gy provides adequate tumor control

Tolerance and efficacy of conformal radiotherapy for hepatocellular carcinoma in cirrhotic patients. Results of the French RTF1 phase 2 trial; Tolerance et efficacite de la radiotherapie de conformation en cas de carcinome hepatocellulaire chez le patient cirrhotique. Resultats de l'essai de phase II RTF1

Energy Technology Data Exchange (ETDEWEB)

Mornex, F.; Girard, N.; Wautot, V.; Khodri, M. [Centre Hospitalier Lyon-Sud, Dept. de Radiotherapie-Oncologie, 69 - Pierre-Benite (France); Merle, P.; Kubas, A.; Trepo, C. [Hopital de l' Hotel-Dieu, Service d' hepatogastroenterologie, 69 - Lyon (France); Beziat, C. [Hopital de l' Hotel-Dieu, Dept. de Radiologie, 69 - Lyon (France)

2005-11-15

Purpose. - While some patients presenting with hepatocellular carcinoma (HCC) benefit from curative therapies (transplantation, surgery, percutaneous ablation), others are only candidates for palliative options such as chemo-embolization or symptomatic care. Although conventional external-beam radiotherapy of the liver is regarded as little efficient and potentially toxic in cirrhotic patients, 3-dimensional conformal radiotherapy (CRT), by decreasing the amount of normal liver included in the radiation portal, allows dose escalation to occur without increasing the risk of radiation-induced hepatitis. This trial was designed to assess the efficacy and tolerance of CRT for small-size HCC in cirrhotic patients. Patients and methods. - Prospective phase II trial including stage A/B cirrhotic patients with small-size HCC not suitable for curative treatments; CRT consisted in a standard fractionation radiation, with a total dose of 66 Gy. Results. - Twenty-seven patients were included, 15 of whom had previously been treated for HCC; mean age was 68. Among the 23 assessable patients, 18 (78%) presented with complete response, 3 (13%) with partial response, and 2 with no response. Acute complications occurred in 24 patients, and were mainly acceptable (grade 1/2: 22 patients, grade 3/4: 11 patients, 4 (15%) of whom had clinical and/or hematological toxicities). Only 2 (9%) grade 3/4 clinical and/or hematological late toxicities are reported. Conclusion. - CRT is a non-invasive curative technique highly suitable for small-size HCC in cirrhotic patients; further investigations are needed to compare it to the other available treatments, and to integrate it into the curative therapeutic algorithm of HCC. (author)

External radiation therapy in early stage prostate cancer

International Nuclear Information System (INIS)

Sandler, Howard M.

1996-01-01

Optimal therapy for adenocarcinoma of the prostate is controversial. Numerous options are available, however, comparison of results is difficult in view of the insufficiency of phase III randomized trials comparing alternative treatment strategies. These options include such strategies as no curative therapy (so-called watchful waiting), radiotherapy (external and/or internal), cryotherapy, or radical prostatectomy. Clearly, a broad spectrum of clinical approaches. When reported experiences involving radiation therapy and radical prostatectomy are compared, surgical patients tend to be younger, of earlier stage, of higher performance status, and have lower pre-therapy PSA. These prognostic factors influence the probability of disease control, and since patient selection can have a profound impact on results reporting, these issues need to be carefully controlled. A review of patients who are potentially candidates for surgery at the University of Michigan treated with conformal therapy external beam treatment, indicates that these relatively early patients are doing well. These issues will be elaborated upon further during the presentation

Anal wall sparing effect of an endorectal balloon in 3D conformal and intensity-modulated prostate radiotherapy.

NARCIS (Netherlands)

Smeenk, R.J.; Lin, E.N.J.T. van; Kollenburg, P. van; Kunze-Busch, M.C.; Kaanders, J.H.A.M.

2009-01-01

BACKGROUND AND PURPOSE: To investigate the anal wall (Awall) sparing effect of an endorectal balloon (ERB) in 3D conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) for prostate cancer. MATERIALS AND METHODS: In 24 patients with localized prostate carcinoma, two planning

Proton external beam in the TANDAR Accelerator; Haz externo de protones en el acelerador TANDAR

Energy Technology Data Exchange (ETDEWEB)

Rey, R; Schuff, J A; Perez de la Hoz, A.; Debray, M E; Hojman, D; Kreiner, A J; Kesque, J M; Saint-Martin, G; Oppezzo, O; Bernaola, O A; Molinari, B L; Duran, H A; Policastro, L; Palmieri, M; Ibanez, J; Stoliar, P; Mazal, A; Caraballo, M E; Burlon, A; Cardona, M A; Vazquez, M E; Salfity, M F; Ozafran, M J; Naab, F; Levinton, G; Davidson, M; Buhler, M [Departamento de Fisica, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, C.P. 1650 San Martin, Buenos Aires (Argentina)

1999-12-31

An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm{sup 2} approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

Proton external beam in the TANDAR Accelerator; Haz externo de protones en el acelerador TANDAR

Energy Technology Data Exchange (ETDEWEB)

Rey, R.; Schuff, J.A.; Perez de la Hoz, A.; Debray, M.E.; Hojman, D.; Kreiner, A.J.; Kesque, J.M.; Saint-Martin, G.; Oppezzo, O.; Bernaola, O.A.; Molinari, B.L.; Duran, H.A.; Policastro, L.; Palmieri, M.; Ibanez, J.; Stoliar, P.; Mazal, A.; Caraballo, M.E.; Burlon, A.; Cardona, M.A.; Vazquez, M.E.; Salfity, M.F.; Ozafran, M.J.; Naab, F.; Levinton, G.; Davidson, M.; Buhler, M. [Departamento de Fisica, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, C.P. 1650 San Martin, Buenos Aires (Argentina)

1998-12-31

An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm{sup 2} approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

Indications for quality assurance in conformal radiotherapy in Italy; Indicazioni per l'Assicurazione di Qualita nella radioterapia ad intensita modulata

Energy Technology Data Exchange (ETDEWEB)

Banci Buonamici, F [Servizio Ospedaliero Dipartimentale Fisica Medica, Azienda Ospedaliera Careggi, Firenze (Italy); DE Angelis, C; Rosi, A; Tabocchini, M A [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita, Roma (Italy); Iotti, C [Radioterapia Oncologica, Arcispedale di Santa Maria Nuova, Reggio Emilia (Italy); Olmi, P [Dipartimento di Radioterapia, Istituto Nazionale per lo studio e la cura dei Tumori, Milano (Italy)

2008-07-01

Intensity-Modulated Radiation Therapy (IMRT) is an advanced and promising technique of external beam irradiation. IMRT is able to conform the dose distribution to the 3D tumour shape also for complex geometries, preserving surrounding normal tissues and reducing the probability of side effects. IMRT is a time consuming and complex technique and its use demands high level quality assurance. It is, therefore, very important to define conditions for its utilization. Professionals of Radiotherapy Centres, with experience in the IMRT use, have constituted a multidisciplinary working group with the aim of developing indications in this field. Purpose of the present document is to highlight relevant aspects of the technique, but also to underline the high complexity of the technique, whose implementation requires extreme attention of the staff of Radiotherapy Centres involved. [Italian] La Radioterapia ad Intensita Modulata (Intensity Modulated Radiation Therapy, IMRT) rappresenta una delle piu avanzate e promettenti tecniche di radioterapia oncologica. La possibilita di adattare la distribuzione della dose terapeutica alla geometria, anche molto complessa, di una massa tumorale consente di salvaguardare in modo ottimale i tessuti sani adiacenti riducendo quindi la probabilita di complicanze. L'IMRT e una tecnica di difficile esecuzione, dispendiosa per tempo impiegato e richiede particolare precisione. E quindi fondamentale cercare di definire in quali situazioni puo essere appropriato il suo impiego. Per questo si e costituito un gruppo di lavoro che ha visto coinvolti, con un approccio multidisciplinare, i Centri Italiani di Radioterapia con maggior esperienza nell'uso di questa tecnica. Questo documento si e posto come obiettivo quello di delineare le peculiarita della tecnica e di evidenziare come la sua elevata complessita esiga il massimo rigore nella sua implementazione.

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

simulated internal motion shifts. Dose increases for adjacent organs at risk were rare. D 33 of the rectum and D 20 of the bladder were increased by more than 5% of the prescription dose in 9 and 1 instances of the 3600 sampled internal motion shifts, respectively. D mean of the right femoral head increased by more than 5% of the prescription dose in 651 (18%) internal motion shifts, predominantly due to the projection of the lateral beams through the femoral head for anterior prostate motion. However, D 2 was not increased by more than 5% for any of the internal motion shifts. These data demonstrate the robustness of the proposed dynamic compensation strategy for correction of internal motion in conformal prostate radiotherapy, with minimal deviation from the original treatment plans even for errors exceeding those commonly encountered in the clinic. The compensation strategy could be performed automatically with appropriate enhancements to available delivery software