Study for high-dose-rate interstitial radiation therapy using remote after-loading technique

组织间放射治疗在头颈部肿瘤尤其是口腔癌的治疗中发挥了重要作用。这种传统的间质治疗的缺点是权衡患者的住院时间和医务人员受到辐射照射可能带来的风险。使用Ir-192的高剂量率后加载技术的使用确保了这一过程不会在植入过程中个人暴露于电离辐射，也不需要患者住院。通过这种远程后加载技术，首先引入刚性引导针或敷贴器(非放射性)，然后插入Ir-192后装源。已开发出几种用于口腔的新型敷贴器。研究了单平面和/或双平面植入时的剂量分布，这种高剂量率的组织间放射治疗的最佳剂量应不同于传统的低剂量率组织间放射治疗，可能的剂量效应系数为1.5~2.0，但需要更多的临床经验。

Interstitial radiation therapy has played an important role in the management of cancer treatment for head and neck cancer, especially for cancer in the oral cavity. Disadvantages by this conventional interstitial therapy is weighted against the hospitalization of the patients and possible risks due to the radiation exposure to the medical staff. The use of high dose-rate after-loading techniques using Ir-192 has assured this procedure without personal exposure to ionizing radiation during the implantation, and without hospitalization of the patients.By this remote after-loading technique, the rigid guide needles or applicators (non-radioactive) are introduced first and subsequently inserting the Ir-192 afterloading sources. Several new applicators for use in the oral cavity has been developed. The dose distribution when using these applicators for single plane implant and/or for double plane implants are studied.Optimum delivery dose by this high dose-rate interstitial therapy should be different from conventional low dose-rate interstitial radiation therapy, with possible dose effect factor 1.5-2.0, although more clinical experience is needed.