TUMOR KINETICS IN HEAD AND NECK CANCER

有新的临床和实验室证据，其中大部分是在 头颈部癌症，即肿瘤克隆性增殖 细胞在放射治疗损害局部控制，是一个重要的 肿瘤治疗抗性的机制。 最近的研究表明， 用这些药物治疗前肿瘤电位倍增时间 治疗内增殖率。 因此，可能的是， 预处理测定电位倍增时间可预测 在治疗过程中特定肿瘤的再生能力。 那么， 将允许选择加速的放射治疗过程， 具有高增殖潜力的肿瘤子集， 耐受的，传统的分割方案，用于肿瘤， 扩散率。 这项研究的主要目的是确定 是否知道治疗前肿瘤潜能倍增时间 将允许选择最有可能受益的患者子集 改变分馏时间表。 溴脱氧尿苷/延迟活检技术的改进将 用于确定人头部肿瘤的预处理动力学 和颈 细胞动力学参数将包括DNA标记 指数、DNA合成期长度和潜在加倍 时间 次要参数包括DNA指数和S期 分数 研究的患者人群将来自RTOG方案 90-03，一项随机试验，总招募目标为648例患者 比较了两个加速的，一个传统的， III期患者超分割放射治疗方案， 头颈部鳞状细胞癌。 之间的相关性 预处理动力学和局部区域控制和生存将是 研究了 分馏时间表对这些的影响 还将研究相关性。

There is emerging clinical and laboratory evidence, much of it in cancers of the head and neck, that proliferation of tumor clonogenic cells during radiotherapy impairs local control and is an important mechanism of tumor therapeutic resistance. Recent studies have linked the pretreatment tumor potential doubling time with these intra-treatment proliferation rates. Thus, it is possible that a pretreatment determination of the potential doubling time might predict a given tumor's ability to repopulate during treatment. This, then, would allow selection of an accelerated course of radiotherapy for that subset of tumors with a high proliferative potential, leaving better tolerated, conventional fractionation schemes for tumors with lower proliferation rates. This study's primary purpose is to determine whether knowledge of the pretreatment tumor potential doubling time will allow selection of a subset of patients most likely to benefit from altered fractionation schedules. Modifications of the bromodeoxyuridine/delayed-biopsy technique will be used to determine pretreatment kinetics in human tumors of the head and neck. Cell kinetic parameters will include the DNA labelling index, length of the DNA synthetic phase and the potential doubling time. Secondary parameters will include the DNA index and S phase fraction. The patient population studied will be from RTOG protocol 90-03, a randomized trial with a total accrual goal of 648 patients that compares two accelerated, one conventional and one hyperfractionated radiotherapy schedule in patients with stage Ill and IV squamous cell carcinoma of the head and neck. Correlations between pretreatment kinetics and localregional control and survival will be investigated. The impact of fractionation schedule upon these correlations will also be studied.