International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2004
Multicenter Study Comparative StudyPatterns of radiotherapy practice for patients with carcinoma of the uterine cervix: a patterns of care study.
To determine the influence of research findings and evolving technology on the practice of radiotherapy in patients with carcinoma of the cervix. ⋯ The sharp increase in the use of chemotherapy in 1999 suggested rapid application of the results from randomized trials. However, considerable heterogeneity in practice patterns remains, particularly in the use of brachytherapy. The practice at small facilities appears to differ significantly from that at larger facilities in several respects, with a statistically significantly larger proportion of treatments at small facilities failing to meet current guidelines for optimal treatment.
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To investigate and compare the biologically effective doses, equivalent doses in 2-Gy fractions, log tumor cells killed, and late effects that can be estimated for the large fractions in short overall times that are now being delivered in various clinically used schedules in several countries for the treatment of cancer in human lungs, liver, and kidney. ⋯ Such large doses can apparently be given, with suitable precautions and experience. Ongoing clinical trials from an increasing number of centers will be reporting the results of tumor control and complications from this new modality of biologically higher doses.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2004
Development of methods for beam angle optimization for IMRT using an accelerated exhaustive search strategy.
The purpose of this article is to explore the use of the accelerated exhaustive search strategy for developing and validating methods for optimizing beam orientations for intensity-modulated radiation therapy (IMRT). Combining beam-angle optimization (BAO) with intensity distribution optimization is expected to improve the quality of IMRT treatment plans. However, BAO is one of the most difficult problems to solve adequately because of the huge hyperspace of possible beam configurations (e.g., selecting 7 of 36 uniformly spaced coplanar beams would require the intercomparison of 8,347,680 IMRT plans). ⋯ Exhaustive search with fast IMRT algorithms provides a novel and realistic approach to study the characteristics of IMRT dose distributions as a function of beam angles and to design practical BAO strategies for IMRT planning.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2004
Defining a radiotherapy target with positron emission tomography.
F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is now considered the most accurate clinical staging study for non-small-cell lung cancer (NSCLC) and is also important in the staging of multiple other malignancies. Gross tumor volume (GTV) definition for radiotherapy, however, is typically based entirely on computed tomographic data. We performed a series of phantom studies to determine an accurate and uniformly applicable method for defining a GTV with FDG-PET. ⋯ An FDG-PET-based GTV can be systematically defined using a threshold SUV according to the regressive function described above. The threshold SUV for defining the target is strongly dependent on the mean target SUV of the target, and can be uniquely determined through the proposed iteration process.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2004
Comparative StudyHigh-dose-rate brachytherapy alone versus whole breast radiotherapy with or without tumor bed boost after breast-conserving surgery: seven-year results of a comparative study.
To report the 7-year results of a prospective study of accelerated partial breast irradiation (APBI) using interstitial high-dose-rate brachytherapy and compare the treatment results with those achieved by standard, whole breast radiotherapy (WBRT), with or without a tumor bed boost (TBB). ⋯ Accelerated partial breast irradiation using interstitial high-dose-rate implants, with proper patient selection and quality assurance, yields similar 7-year results to those achieved with standard breast-conserving therapy. APBI does not increase the risk of elsewhere breast failures.