International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2001
High-dose-rate brachytherapy may be radiobiologically superior to low-dose rate due to slow repair of late-responding normal tissue cells.
Recent analysis of morbidity for patients treated with the continuous hyperfractionated accelerated radiotherapy (CHART) regimen demonstrates that repair half-times for late-reacting normal tissue cells are of the order of 4-5 h, which is considerably longer than previously believed. This would reduce repair of these tissue cells during a course of low-dose rate (LDR) brachytherapy, but have no effect at high-dose-rate (HDR), where there is no repair during, and full repair between fractions, regardless of repair half-time. The effect this has upon radiobiologic comparison of LDR and HDR is the topic of this paper. ⋯ The previously held belief that LDR must be inherently superior radiobiologically to HDR is wrong if the long repair times demonstrated in the recent CHART study are applicable to other late-reacting normal tissues. This could explain why HDR has been so successful in clinical practice, especially for the treatment of cervical cancer, despite previous convictions of radiobiologic inferiority of this modality.
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Int. J. Radiat. Oncol. Biol. Phys. · Jan 2001
The status of radiation oncology training programs and their graduates in 1999.
To keep the profession apprised of current trends in the job market, the American College of Radiology (ACR) studied the employment situation of 1999 radiation oncology graduates and the status and plans of radiation oncology training programs. ⋯ Directors' perceptions of graduates' job prospects remain optimistic, and the employment situation remains the same as in past years, when reported unemployment was approximately 1%-2% or less by six months after graduation.