radiotherapy dosage

..This method estimates the beam intensity in one single step and the computation time is extremely fast and can be finished in less than one minute using a regular PC...

..The benefit of protons is only achieved if a scanning beam is used in which the doses are 10 times lower than with IMRT...

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..For clinical cases, the calculation time is typically 5 minutes for a 1 x 1 mm2 interpolated resolution on an 800 MHz Pentium 4 for a 14.1 x 15.2 cm2 radiographic film...

..035 g cm(-3)), enhanced for the most energetic beam. For denser, and more clinical, densities a better agreement among the sophisticated algorithms with respect to MC was observed...

..Respiratory motion management is also appropriate when the procedure will increase normal tissue sparing. Respiratory motion management involves further resources, education and the development of and adherence to QA procedures...

..Only the radiation dose was a significant factor for predicting an objective response. The results of this study showed that 3D-CRT can theoretically be used for treating primary HCC...

..To determine the maximum tolerated dose of single fraction radiosurgery in patients with recurrent previously irradiated primary brain tumors and brain metastases...

..The dosimetry audit goals were to verify the plan delivery in participating centres, ascertain what tolerances were suitable for head and neck IMRT trials and develop an IMRT credentialing program...

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..To perform a qualitative and quantitative comparison of different treatment planning methods used in different centres for MRI-based brachytherapy (BT) of cervical cancer...

..The authors assessed risk of hypothyroidism in breast cancer patients who were receiving RT to a supraclavicular field, which typically includes a portion of thyroid...

..To test, in a prospective Phase I/II trial, a partial breast irradiation technique using a 103Pd permanent breast seed implant (PBSI) realized in a single 1-h procedure under sedation and local freezing...

..This would allow a reduction in the duration and cost of the development of new treatments...

..Treatment outcomes for stage III and IV oropharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy without prior surgical resection were reviewed...

..We aimed to assess whether stereotactic radiosurgery provided any therapeutic benefit in a randomised multi-institutional trial directed by the Radiation Therapy Oncology Group (RTOG)...

..The purpose of this study was to compare point doses to 3D dose volume parameters for tumour and organs at risk (OARs), and to evaluate the improvement of dose parameters with MR image guided adaptive brachytherapy (IGABT)...

..To investigate the value of dose-volume histogram (DVH) parameters for predicting local control in magnetic resonance (MR) image-guided brachytherapy (IGBT) for patients with cervical cancer...

..To assess radiobiological restrictions and tolerance doses as well as other toxic effects derived from repeated applications of single-fraction high dose rate irradiation of small liver volumes in clinical practice...

..We studied planning and delivery in patients who underwent RapidArc for locally advanced head-and-neck cancer (HNC)...

..To evaluate the regional relapse rate in the elective neck using intensity-modulated radiotherapy (IMRT) for head-and-neck cancer...

..In this study we sought to determine the threshold dose for local control of occult micrometastases in patients undergoing CT (computed tomography)-guided brachytherapy of colorectal liver metastases...

..To determine local tumor control after CT-guided brachytherapy at various dose levels and the prognostic impact of extensive cytoreduction in colorectal liver metastases...

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..Additional follow-up will be needed to assess the long-term effects of these larger fraction sizes on normal-tissue sequelae and the impact of this fractionation schedule on treatment efficacy...

..CONCLUSIONS: Adjuvant chemotherapy has a significant survival benefit in patients with resected pancreatic cancer, whereas adjuvant chemoradiotherapy has a deleterious effect on survival...

..Alternative CQA and PQA procedures are discussed. The literature is reviewed and discussed with special respect to quality assurance in IMRT of prostate cancer patients...

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..This study reports the systematic development of our concept applied in clinical routine...

..The protocol employed stringent dosimetric guidelines in the treatment of locally advanced head-and-neck squamous cell carcinomas (HNSCC) with radiotherapy alone using IMRT and the simultaneous integrated boost (SIB) technique...

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..It is FDA approved for liver metastases secondary to colorectal carcinoma and is under investigation for treatment of other liver malignancies, such as hepatocellular carcinoma and neuroendocrine malignancies...

..To describe a new intensity-modulated radiotherapy (IMRT) technique using helical tomotherapy for whole abdominal irradiation (WAI) in patients with advanced ovarian cancer...

..However, there were controversies regarding the applicability of the results to patients in endemic regions. This study aims to confirm the findings of the 00-99 Trial and its applicability to patients with endemic NPC...

..We now evaluate whether IMRT has resulted in improved outcomes for a larger cohort of patients with longer follow-up...

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..To evaluate the impact of marker-based position verification, using daily imaging and an off-line correction protocol, by calculating the delivered dose to prostate, rectum and bladder...

..In parallel, radiation therapy philosophy must evolve, and the aim of treatment should be to deliver the minimal effective radiation therapy rather than the maximal tolerable dose...

..The analysis was designed to identify the optimal radiation technique for patients with malignant glioma...

..To review the experience with and evaluate the treatment plan for helical tomotherapy for the treatment of oropharyngeal cancer...

..To report on the planning procedure, quality control, and clinical implementation of intensity-modulated arc therapy (IMAT) delivering a simultaneous integrated boost (SIB) in patients with primary irresectable cervix carcinoma...

..In this paper, we present a comprehensive analysis of the updated clinical data to derive a self-consistent set of parameters for the linear-quadratic (LQ) model...

..This report, while not prescribing specific procedures, provides the framework and guidance to allow clinical radiation oncology physicists to make judicious decisions in implementing a safe and efficient IMRT program in their clinics...

..The determination of gamma throughout the measured dose distribution provides a presentation that quantitatively indicates the calculation accuracy. Examples of a 6 MV beam penumbra are used to illustrate the gamma index...

..To determine the feasibility and toxicity of delivering stereotactic radiosurgery to patients with locally advanced pancreatic cancer...

..The pattern of recurrence suggests that careful escalation of the dose to targets judged to be at highest risk may improve tumor control...

..To quantify the relative peripheral photon doses (PD) to healthy tissues outside the treated region for different IMRT technologies and linac head designs...

..Because xerostomia and dysphagia are the main causes of decreased quality of life after radiotherapy for head and neck cancer, the prevention of these two complications will form the focus of this review...

..The developed procedure is applicable to a wide range of accelerators, and has an acceptable accuracy and processing time...

..In order to assess potential effects of a dose escalation in certain sub-volumes based on choline PET imaging a mathematical dose-response model was developed...

..a lower dose of IMRT combined with high-dose-rate (HDR) brachytherapy to increase the biologically effective dose of IMRT...

..These characteristics include the accelerator source distribution and multileaf collimator (MLC) geometry...

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..To evaluate the predictive value of dose-volume histogram (DVH) parameters for late side effects of the rectum, sigmoid colon, and bladder in image-guided brachytherapy for cervix cancer patients...

..These data provide useful information for assessing alterations to beam models in the planning system. IMRT is enhanced by the addition of statistical process control to traditional quality control procedures...

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..In this report, doses to normal tissue from IMRT and our previous conformal sequential boost technique are compared...

..The redistribution of dose improved tumor control probability by factors between 1.03 and 4.27 for a range of model tumors...

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..1843A>G, c.562-14A>G, c.722C>T), Rad51 (c.-3429G>C, c.-3392G>T), Lig4 (c.26C>T, c.1704T>C), Ku70 (c.-1310C>G), and Ku80 (c.2110-2408G>A) and the occurrence of acute reactions after radiotherapy...

..The methodology in defining appropriate tolerances, described in this article, is based on an interpretation of IMRT QA results from IMRT plans deemed safe to deliver...

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..EUD may be considered as a robust and simple parameter correlated with the risk of late rectal bleeding...

..Calculations were performed for prostates of different edema magnitudes and durations, and for tumour cells of different repair rates and repopulation rates...

..The offline dose compensation technique allows further margin reduction and can complement the online guidance by compensating for uncertainties that cannot be reduced online, thereby increasing the confidence in IGRT delivery...

..The design provides a representative but reproducible system for QA in the prostate radiotherapy process, from CT scan to treatment. Setup errors are not eliminated, but minimised and estimated...

..Quality control of TomoTherapy patients was reduced to a total of approximately 25 min per patient...

..To compare dosimetrically four different techniques of accelerated partial breast irradiation (APBI) in the same patient...

..To study the impact on nodal coverage and dose to fixed organs at risk when using daily fiducial localization of the prostate to deliver intensity-modulated radiotherapy (IMRT)...

..However, the degradation was not significant for the three-phase sequential boost prostate IMRT technique and for the margin sizes used in our institution...

..The findings of this study suggest that the clinical results of lung SBRT trials should be carefully evaluated in comparison with the actual dose given to patients...

..However, if the irradiated portion of the rectum is empty, NDVH is a good surrogate for DWH...

..We conclude that LO-IMRT with gEUD cost functions could allow dose escalation in pancreas tumors with concomitant reduction in doses to organs at risk as compared with traditional 3DCRT...

..The purpose of this study was to quantitatively assess the impact of this CTV reduction on the expected rectal and bladder dose sparing...

..Over a patient population, the variation in rectal dose is reduced by increasing the number of pre-treatment CT scans...

..This article describes several of the new treatments along with the effects of radiation on the cells and tissues. Technological advances and research will continue to result in improvements in the field...

..Dose distributions produced with carbon ions, however, are more sensitive to setup errors, which have to be considered during treatment...

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..This indicates that the proposed hybrid physico-biological method can be used for the generation of clinically acceptable plans...

..These results show that this detector can be used for 2D dosimetry of x-ray photon beams, supplying a good spatial resolution and sensibly reducing the time spent in dosimetric verification of complex radiation fields...

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..The goal of this work is to evaluate the dosimetric characteristics of a new 2D diode array (MapCheck from Sun Nuclear Corporation, Melbourne, Florida) and assess the role it can play in routine IMRT QA...

..To develop a real-time, image-guided intraoperative high-dose-rate brachytherapy system...

..The application of the algorithm using a test case, a prostate and a head and neck tumour case is shown. The results are compared with MO inverse planning using a gradient-based optimization algorithm...

..This method provides an important understanding of actual delivered doses and has the potential to provide quantitative information to use as a guide for adaptive radiation treatments...

..Finally, the role of radiation protectors is beginning to be addressed. It is hoped that these advances will eliminate toxicity associated with radiotherapy and increase cure rates...

..This investigation is being expanded using sequential PET images to model tumor regression and compare brachytherapy and AGIMRT throughout the course of therapy...

..Treatment of childhood low-grade gliomas is a challenging issue owing to their low incidence and the lack of consensus about "optimal" treatment approach...

..The biochemical control rates are between 80 and 90%. Toxicity consists of urine retention and proctitis, occurring in 10-20% of the patients...

..The results of the latter two methods have only been discussed briefly, as they yielded the same conclusions as the NG method...

..5%) is very good: the dose difference at isocenter is 2.1% (1 standard deviation) for a "Prostate" site and 2.9% (1 standard deviation) for the "Head and Neck" site...

..The planning time was significantly reduced as well. This technique is an effective means of optimizing individualized treatment plans...

..We show an example with a prostate implant and compare results obtained by variance and dose-volume histogram (DVH) based objectives...

..7 and 6.3 Gy for uniform doses. We conclude that estimation of alpha/beta without taking into account dose heterogeneity and inter-patient variation may underestimate the actual value alpha/beta...

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..The enhanced control over the final plan may greatly facilitate the IMRT treatment planning process...

..To illustrate the feasibility of DAO applied to IMAT, several cases are presented, including a cylindrical phantom, a head and neck patient and a prostate patient...

..Further escalation of the EUD is possible when the homogeneity constrained is relaxed, but the relative benefit of beam-fringe sharpening then decreases...

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..Lowering radiation dose by an equivalent factor may produce lower radiation toxicity with similar efficacy, while preserving the option of subsequent retreatment(s) with thermoradiotherapy in order to further extend patient survival...

..The simultaneous property of these algorithms is ideally suited to parallel computing technologies...

..The development, testing and validation of such predictive algorithms will improve patient care by reducing the incidence of lung injury and facilitate "safe" dose escalation for intrathoracic cancers. ..

..They will be made publicly available via the Internet. The overall impact of this work will be to facilitate significant reduction in thoracic radiotherapy-induced injury via accurate prediction. ..

..This will allow clinics around the country to take advantage of the computational accuracy of this state-of-the-art clinical tool. ..

..The primary objective of this project is to develop a new method to consider the effects of edema in radiation dosimetry and treatment planning so that the efficacy of this therapy can be optimized for each patient. ..

..The primary objective of this project is to develop a new method to consider the effects of edema in radiation dosimetry and treatment planning so that the efficacy of this therapy can be optimized for each patient. ..

..We expect the results of our analyses to play an important role in furthering the development of conformal techniques in RT of the prostate and other pelvic sites. ..

..Standardized clinical and data collection procedures will be employed, and standardized forms will be used in all centers. Central training and certification of all study staff will be required. ..

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..The work described in this application is intended to develop and evaluate such an approach. ..

..It will allow obtaining medical images with exquisite resolution, increased depth of field and a greater depth of penetration, and lead to new capabilities for improved diagnostic imaging and disease management. ..

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..In the future, we expect that the lower-risk treatments will result in fewer second cancers and this will translate into longer, higher-quality lives for survivors of childhood cancer (presently 270,000 persons in the United States). ..

..Our goal is to pave the way for a strategy in the future that will allow administration of effective therapy, improve safety, and preserve the esophagus in some patients. ..

..abstract_text> ..

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..This information will lead to algorithms that accurately predict the risk of cardiopulmonary injury, facilitate the design of "safer" 3D dose distributions, and thus improve patient care. ..

..This approach could be used to select patients for individualized therapy using targeted sensitizing agents based on the proposed preclinical studies. ..

..Furthermore, shorter treatment planning times will reduce the overall cost. ..

..This approach could be used to select patients for individualized therapy using targeted sensitizing agents based on the proposed preclinical studies. ..

..The work described in this application is intended to develop and evaluate such an approach. ..

..They will be made publicly available via the Internet. The overall impact of this work will be to facilitate significant reduction in thoracic radiotherapy-induced injury via accurate prediction. ..

..This information will lead to algorithms that accurately predict the risk of cardiopulmonary injury, facilitate the design of "safer" 3D dose distributions, and thus improve patient care. ..

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..3. To explore whether wine in combination with megestrol acetate alters the hormonal milieu that modulates appetite. We will specifically look for alterations of circulating leptin, ghrelin, and neuropeptide y. ..

..This K23 grant application will serve as a springboard to allow her to delve into the pathophysiology of this syndrome and to develop into an independent clinical investigator. ..

..These two pilot studies will allow us to lay the groundwork for such larger trials. Our ultimate goal is to help cancer patients who suffer from anorexia. ..

..The ultimate goal of the proposed studies is to improve the prognosis of patient with this fatal disease. ..

..MV-NIS, given by vein, should kill myeloma cells. Using simple scans, we should be able to track where MV-NIS goes in the body. ..

..This approach could be used to select patients for individualized therapy using targeted sensitizing agents based on the proposed preclinical studies. ..

..MV-NIS, given by vein, should kill myeloma cells. Using simple scans, we should be able to track where MV-NIS goes in the body. ..

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..If the promise of these techniques is fulfilled, clinicians will have a new powerful tool for management of peripheral vascular disease, based on fundamental pathophysiology. ..

..29, Medical Physics Publishing, Madison, Wl. ..

..The proposed approach to modulate tumor hypoxia will avoid possible complications and toxicity arising due to oral or injections of drugs. If successful, this approach potentially could be immediately extended for clinical applications. ..

..MV-NIS, given by vein, should kill myeloma cells. Using simple scans, we should be able to track where MV-NIS goes in the body. ..

..Finally, effects of tissue heterogeneity and self-shielding effects of catheters and stents for photons and beta particles will also be investigated. ..

..abstract_text> ..

..A Petri-dish-like micro SEC will be developed for the determination of doses at the interface of high Z materials and tissues with capability of measuring doses averaged over layers of about 10 pm thickness. ..

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..The goals of the project are to develop tools for the optimization of dose distributions produced within a target volume and uniformity of dose along and around a blood vessel. ..

..The research plan will attempt to exploit the many unique features of the SEC, namely its reusability, high sensitivity and LET discrimination. ..

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