RESPONSE OF CANINE TUMORS TO NONSTANDARD FRACTIONATION

本研究将使用犬中自然发生的鼻癌进行。 目的是评价肿瘤和急性放射反应， 正常组织对非常规分离方案的延迟响应。 有人提出，辐射的加速分馏 治疗剂量可能更有效地控制快速增殖 肿瘤的 也有人建议，减少一些后期正常 组织并发症可以用较小的每部分剂量来实现。 如果 各部分之间的治疗间隔和给药的总时间 总的辐射剂量可以减少，肿瘤将有更少的 重新繁殖和再生的机会。 如果剂量反应曲线 急性和迟发反应正常组织的靶细胞显著 不同的、反应较晚的正常组织可以通过较小的剂量而幸免 而急性反应组织将不会经历 相应减少伤害。 肿瘤被认为是急性 反应组织。 这项研究旨在验证这一理论 并给出剂量反应曲线的一般形状的估计， 肿瘤和急性及迟发反应组织。 可变总剂量将是 给三组患有鼻癌的狗。 每组将 接受不同剂量的每部分，以实现可变的总剂量 剂量 所有照射剂量将在四周的间隔内给予。 将进行分析，以确定肿瘤控制的50%概率， 一年;急性反应的反应水平的概率 组织，特别是眼睛的结构;以及晚期 坏死 这些数据将允许评价剂量大小的影响 肿瘤控制、早期效应和 晚期并发症 将为不同的 使用从三种不同剂量中的每一种获得的数据， 分数组

This study will be done with naturally occurring nasal carcinomas in dogs. The purpose is to evaluate the radiation response of tumor and acute and late responding normal tissues to nonconventional fractionation schemes. It has been proposed that accelerated fractionation of the radiation therapy dose might be more effective for control of rapidly proliferating tumors. It has also been proposed that some reduction in late normal tissue complications could be achieved with smaller doses per fraction. If the intertreatment interval between fractions and the overall time to give a total dose of radiation can be reduced, tumors would have less opportunity for repopulation and regrowth. If the dose response curves of target cells for acute and late responding normal tissues are significantly different, late responding normal tissues may be spared by smaller doses per fraction while acutely responding tissues will not experience a corresponding decrease in injury. Tumors are considered to be acutely responding tissues. The research proposed is designed to test the theory and to give estimates of the general shapes of dose response curves for tumor and acute and late responding tissues. Variable total doses will be given to three groups of dogs with nasal carcinomas. Each group will receive a different size of dose per fraction to achieve the variable total doses. All irradiation doses will be given in an interval of four weeks. Analysis will be done to determine the 50% probability for tumor control at one year; the probability for levels of response of acutely responding tissues, particularly the structures of the eye; and probability for late necrosis. The data will permit evaluation of the effect of size of dose per fraction on total dose required for tumor control, early effects and late complications. Isoeffect curves will be constructed for the various tissues using data obtained from each of the three different dose per fraction groups.