International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2006
Radiation therapy for Ewing's sarcoma: results from Memorial Sloan-Kettering in the modern era.
To evaluate the outcomes of patients with Ewing's sarcoma family of tumors (ESFT) treated with modern radiotherapy techniques with MRI along with optimal chemotherapy. ⋯ In this unfavorable cohort of ESFT patients, radiation therapy was an effective modality for local control, especially for patients without metastases. The presence of metastases at diagnosis is a predictive factor not only for death but also for local failure.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2006
PSA kinetics after prostate brachytherapy: PSA bounce phenomenon and its implications for PSA doubling time.
To analyze prostate-specific antigen (PSA) kinetics in patients treated with prostate brachytherapy (PI) with a minimum of 5 years of PSA follow-up. ⋯ Patients experiencing a PSA bounce are more likely to be younger and will have a better bRFS. The PSADT cannot differentiate a PSA bounce from bF. The time to the initial PSA rise after nadir is an excellent discriminator of bF from PSA bounce. The time of the PSA rise after nadir occurs far sooner for a PSA bounce than for bF. This factor should be considered when assessing a patient with a rising PSA level after PI before a patient is administered salvage therapy.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2006
Repeat CT imaging and replanning during the course of IMRT for head-and-neck cancer.
Many patients with head-and-neck (H&N) cancer have tumor shrinkage and/or weight loss during the course of radiotherapy. We conducted this retrospective study to determine the dosimetric effects of repeat computed tomography (CT) imaging and replanning during the course of intensity-modulated radiotherapy (IMRT) on both normal tissues and target volumes. ⋯ Repeat CT imaging and replanning during the course of IMRT for selected patients with H&N cancer is essential to identify dosimetric changes and to ensure adequate doses to target volumes and safe doses to normal tissues. Future prospective studies with larger sample sizes will help to determine criteria for repeat CT imaging and IMRT replanning for H&N cancer patients undergoing radiotherapy.
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Int. J. Radiat. Oncol. Biol. Phys. · Feb 2006
Radiobiologic effect of intermittent radiation exposure in murine tumors.
In stereotactic irradiation using a linear accelerator, the effect of radiation may be reduced during intermittent exposures owing to recovery from sublethal damage in tumor cells. After our previous in vitro study suggesting this phenomenon, we investigated the issue in murine tumors. ⋯ The results of the present in vivo studies were different from those of our in vitro studies in which cell survival increased significantly when a few minutes or longer intervals were posed between fractions. This suggests that recovery from sublethal damage in vivo may be counterbalanced by other phenomena such as reoxygenation that sensitizes tumor cells to subsequent irradiation.