International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 1999
Investigation of hypersensitivity to fractionated low-dose radiation exposure.
Hypersensitivity to cell killing of exponentially growing cells exposed to X-rays and gamma rays has been reported for doses below about 0.5 Gy. The reported results have been interpreted to suggest that a dose of 0.5 Gy or less is not sufficient to trigger an inducible repair mechanism. The purpose of this study was to examine this suggested hypersensitivity after multiple low doses (0.3 Gy) of gamma rays where a) the effect would be expected to be significantly magnified, and b) the effect might be of clinical relevance. ⋯ These experiments were specifically designed to magnify and probe possible clinical implications of proposed "low-dose hypersensitivity" effects, in which significant deviations at low doses from the LQ model have been suggested. In fact, the results at low doses per fraction were consistent with LQ predictions based on higher dose per fraction data. This finding is in agreement with the well-documented utility of the LQ approach in estimating isoeffect doses for alternative fractionation schemes, and for brachytherapy.
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Int. J. Radiat. Oncol. Biol. Phys. · Aug 1999
Mature results of a pilot study of pelvic radiotherapy with concurrent continuous infusion intra-arterial 5-FU for stage IIIB-IVA squamous cell carcinoma of the cervix.
To evaluate the long-term results of continuous infusion intra-arterial 5-fluorouracil (CI IA 5-FU) given with concurrent pelvic radiotherapy (RT) for FIGO stage IIIB-IVA carcinoma of the cervix. ⋯ While this series is small, the fact that 4 patients with massive Stage IIIB tumors survived after a total radiation dose of only 50 Gy suggests that RT with CI IA 5-FU deserves further study. Modifications in dose, technique, and route of administration should reduce toxicity, and the addition of intracavitary RT should improve the local effectiveness of combined treatment.