International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · May 2003
Clinical TrialTolerance of organs at risk in small-volume, hypofractionated, image-guided radiotherapy for primary and metastatic lung cancers.
To determine the organ at risk and the maximum tolerated dose (MTD) of radiation that could be delivered to lung cancer using small-volume, image-guided radiotherapy (IGRT) using hypofractionated, coplanar, and noncoplanar multiple fields. ⋯ Small-volume IGRT using 60 Gy in eight fractions is highly effective for the local control of lung tumors, but MTD has not been determined in this study. The organs at risk are extrapleural organs such as the esophagus and internal chest wall/visceral pleura rather than the pulmonary parenchyma in the present protocol setting. Consideration of the uncertainty in the contouring of normal structures is critically important, as is uncertainty in setup of patients and internal organ in the high-dose hypofractionated IGRT.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2003
Comparative StudySequencing radiotherapy for soft tissue sarcoma when re-resection is planned.
To evaluate whether disease outcome for localized soft-tissue sarcoma (STS) excised before referral to a specialist center and there re-resected was influenced by the timing of radiation therapy (XRT)-before or after re-resection. ⋯ Patients who present after total but oncologically inadequate excision of STS can receive approximately 50 Gy before re-resection or approximately 60 Gy after re-resection, with approximately equivalent, satisfactory local control and overall disease outcome. Decisions as to the most appropriate treatment sequence for any individual patient can be made regardless of considerations as to the effectiveness of one sequence compared with the other.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2003
Prediction of the benefits from dose-escalated hypofractionated intensity-modulated radiotherapy for prostate cancer.
To estimate the benefits of dose escalation in hypofractionated intensity-modulated radiotherapy (IMRT) for prostate cancer, using radiobiologic modeling and incorporating positional uncertainties of organs. ⋯ Dose escalation to the prostate using IMRT to deliver daily doses of 3 Gy was predicted to significantly increase tumor control without increasing late rectal complications, and currently this prediction is being tested in a clinical trial.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2003
The relationship between local dose and loss of function for irradiated lung.
To determine the relationship between the local radiation dose and the decrease in lung function associated with thoracic irradiation. ⋯ The decrease in pulmonary diffusion capacity correlates with the local dose to irradiated lung. Amifostine significantly reduces the loss in DL(CO). A local dose-loss relationship for normalized DL(CO) can be extracted from DVH data. This relationship allows an estimate of the loss of function associated with a radiation treatment plan. Different plans can thus be compared without resort to an empiric DVH reduction algorithm. The very low (13 Gy) threshold for deterioration of DL(CO) suggests that it is better to treat a little normal lung to a high dose than to treat a lot to a low dose.
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Int. J. Radiat. Oncol. Biol. Phys. · May 2003
Comparative StudyPreliminary evaluation of low-grade toxicity with conformal radiation therapy for prostate cancer on RTOG 9406 dose levels I and II.
To evaluate the rates of low-grade late effects in patients treated for prostate cancer on Radiation Therapy Oncology Group (RTOG) 9406. ⋯ Morbidity of 3D-CRT in the treatment of prostate cancer is low. It is important to continue to closely examine late effects in patients treated in RTOG 9406. The primary objective of dose escalation without an increase rate of >/= Grade 3 sequelae has been achieved. However, the reduction in Grade 3 complications may have resulted in a higher incidence of Grade 1 or 2 late effects. Because Grade 2 late effects may have a significant impact on a patient's quality of life, it is important to reduce these complications as much as possible. Clinical trials should use quality-of-life measures to determine that trade-offs between severity and rates of toxicity are acceptable to patients.