International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Concurrent chemotherapy and reduced-dose cranial spinal irradiation followed by conformal posterior fossa tumor bed boost for average-risk medulloblastoma: efficacy and patterns of failure.
To review the efficacy and patterns of failure in average-risk medulloblastoma patients treated with concurrent chemotherapy and reduced-dose cranial spinal irradiation and a conformal tumor bed boost. ⋯ The treatment of average-risk medulloblastoma with chemotherapy, reduced-dose cranial spinal irradiation, and a conformal tumor bed boost results in survival rates and local control rates comparable to those in contemporary studies. A reduction in the amount of posterior fossa treated to the high dose is possible. These results need to be corroborated in a large, cooperative group study.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Dosimetric correlates for acute esophagitis in patients treated with radiotherapy for lung carcinoma.
Acute esophagitis is a common complication of radiotherapy (RT) for non-small-cell carcinoma of the lung. Previous reports have related esophagitis to dosimetric parameters such as the length of the irradiated esophagus, maximal dose, or volume of the organ treated beyond a threshold dose. However, when using oblique beams, a portion of the esophageal circumference may be outside the treated field, resulting in partial esophageal irradiation. Therefore, our aim was to determine whether the irradiated esophageal surface area and/or esophageal volume are predictive of acute esophagitis in relation to other clinical and treatment-related factors. ⋯ The esophageal surface area receiving > or =55 Gy, the esophageal volume receiving > or =60 Gy, and the use of concurrent chemotherapy were the most statistically significant predictive factors for early esophagitis. Adequate dosimetric coverage of the planning target volume remains the goal of RT planning. High values of A(55) and/or V(60) are indicative of the development of acute esophagitis and may indicate a need to explore alternative RT planning options.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Evaluation of the influence of breathing on the movement and modeling of lung tumors.
Respiration causes movement and potential shape change in lung tumors that are not fully appreciated using conventional free-breathing CT models for radiotherapy planning. Although target expansion has the potential to ensure proper tumor coverage in the face of motion on a free-breathing CT scan, large variations in how individual patients' tumors move may make such expansions difficult to uniformly define. In addition, excessive expansion may result in the unnecessary inclusion of normal lung in the treated volume. This study was designed to evaluate the influence of breathing movement on tumors and to assess the validity of the free-breathing CT scan for target delineation in the lung. ⋯ Traditional methods of expanding the GTV to CTV by 1 cm are less than ideal. This method tends to include more normal lung than necessary and may lead to marginal miss. Interpatient tumor movement variations further prohibit defining a simple rule for nonuniform expansion that would minimize the volume of normal lung in the target. Although the development of target volumes by combining information from breath-hold CT scans at inhale and exhale states shows some promise in minimizing excess lung irradiated while maintaining adequate tumor coverage, further tests of breathing reproducibility need to be performed to provide a confident baseline for defining target expansions by this technique.
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Randomized Controlled Trial Clinical TrialImpact of volume and location of irradiated rectum wall on rectal blood loss after radiotherapy of prostate cancer.
To identify dose-volume parameters related to late rectal bleeding after radiotherapy for prostate cancer. ⋯ For any rectal bleeding within 3 years, an overall incidence of 33% was observed for patients treated to 66 Gy. For this endpoint, a volume-effect relation was found for DVH parameters of the relative rectal wall volume. This relationship appeared to be most significant for the rectum without the anal region and for the higher dose levels (50-60 Gy).
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Int. J. Radiat. Oncol. Biol. Phys. · Mar 2004
Randomized Controlled Trial Clinical TrialImpact of radiotherapy parameters on outcome in the International Society of Paediatric Oncology/United Kingdom Children's Cancer Study Group PNET-3 study of preradiotherapy chemotherapy for M0-M1 medulloblastoma.
To analyze the impact of radiotherapy (RT) parameters on outcome in a randomized study of pre-RT chemotherapy for M0-M1 medulloblastoma. ⋯ The results of this study have confirmed the importance of the duration of RT for medulloblastoma. Also, attention to detail when planning RT is important, as illustrated in the case of PF field placement.