50例鼻咽癌局部复发的原因分析

Analysing Causes in 50 Patients with Local Recurrence after Radiotherapy for Nasopharyngeal Carcinoma

本文分析50例鼻咽癌放射治疗后局部复发的原因。首先引起重视的是放疗疗程普遍延长．平均62.1±9.6（46～89）天．仅9例（占18％）在原计划疗程内完成放疗，其余41例（占82％）皆因各种原因中断放疗而延长了疗程。根据肿瘤在放疗后将加速再增殖产生新的肿瘤细胞，疗程赵延长，产生的新肿瘤细胞数越多．越难控制的理论，故认为疗程延长是本组局部复发的重要原因。其次从复发部位的分布看，最多见的是上部（颅底）复发．占60％．其次是后部复发（23％）和前部复发（13％）：放疗前T分期的早晚基本上不影响复发部位的上述分布比例．提示各个部位的复发有其自身的特点。故逐个部位作了分析研究．有针对性的提出了防止复发的措施。最后探讨了复发时间的早晚和T分期的早晚呈负相关的可能原因。

The pnrpose of the study reported here was to investigate whether there were some of close relatlonship between the characterisics of irradiation and local failures in nasopharyngeal carcinoma (NPC). This study showed that the average overall treatment time of irradiation in these patients with locnl failure was 60. 1±9. 6 days (range 47~89 days) . which was much longer than the time planned. This appearance was consitent with the theory that a significant Ioss of local control was observed with prolongation in radiotherapy, because rapidly proliferating turnor underwent consfderahle clonogen repopulation during a lengthy course of irradiation. Accoding to CT fin dings it was found that local failures at the superior aspect, the posterior aspect. and the anterior aspect of the nasopharynx accounted for 60 ％. 23％ and 13 % respectively. This Phenomenon indicated that radiotherilpists should pay more attention to avoiding underdosage and geographic miss of the lesions at the level of the skull bilse as well as the poststyloid space. lastly, that the median times from irradiation to expression of local failures for T1. T2, T3,and T4 lesions of NPC were 38. 27, 12and 9. 5 months respeetively. was found,and their relationstip was dicussed preliminarily.