不同鼻咽癌调强放疗剂量分割模式的近期疗效分析

Short-term curative effect of different dose fractionation patterns of intensity-modulated radiotherapy on nasopharyngeal carcinoma

目的 探讨不同鼻咽癌调强放疗剂量分割模式的近期疗效和不良反应。 方法 选取2011 年6 月- 2013 年3 月我科收治的98 例鼻咽癌患者。应用螺旋断层治疗技术，改变了传统剂量分割模式，具体处方剂量为：鼻咽部原发肿瘤（pGTV nx ） 及可见的转移淋巴结（pGTV nd ） 67.5 Gy/30 F ，高危临床靶区（CTV 1 ） 60 Gy/30 F ，低危临床靶区（CTV 2 ） 54 Gy/30 F ，5 次/ 周。根据RECIST 1.0 版实体肿瘤疗效评价标准评价近期疗效，参照RTOG/EORTC 标准，在治疗结束时和治疗结束后一个月评价急性反应。根据LQ 放射生物模型计算改变剂量分割模式的生物等效剂量（biological effective dose，BED）。 结果 随访1 -22 个月，中位随访12 个月。鼻咽部原发灶和颈部转移淋巴结消退率分别为90.8% 和93.9%。皮肤、黏膜、唾液腺、咽食管1 - 2 级急性反应发生率分别92.8%、89.8%、96.9%、98%，3 - 4 级急性反应发生率分别为4.1%、7.1%、0%、2%。对于肿瘤组织，本组单次2.25 Gy，总剂量67.5 Gy，照射30 次/40 d 即67.5 Gy（30×2.25 Gy） 剂量分割模式的BED 为62.9 Gy，等效于单次2 Gy，总剂量72 Gy。对于正常组织晚期反应，等效于单次2 Gy，总剂量70 Gy。 结论 改变调强放疗剂量分割模式治疗鼻咽癌的近期疗效较好，不良反应较轻，患者可耐受，同时缩短了总治疗时间，相应地减轻了患者的经济负担。远期疗效有待进一步观察。

Objective To study the short-term curative effect of different dose fractionation patterns of intensity-modulated radiotherapy （IMRT） on nasopharyngeal carcinoma （NPC） and its adverse reactions. Methods Ninety-eight NPC patients admitted to our departments from June 2011 to March 2013 were included in this study. The patients underwent helical tomotherapy with modified dose fractionation patterns at the dose of 67.5 Gy/30 F for pGTV nx and pGTV nd , at the dose of 60 Gy/30 F for CTV 1 , and at the dose of 54 Gy/30 F for CTV 2 , 5 F a week. The short-term curative effect was assessed according to the RECIST 1.0 criteria and the acute reactions were assessed according to the RTOG/EORTC criteria at the end of and 1 month after radiotherapy, respectively. Biological equivalent dose （BED） of the modified dose fraction patterns was calculated according to the LQ radiobiological model. Results The patients were followed up for 1-22 months （median 12 months）. The remission rate of nasopharyngeal primary lesions and positive lymph nodes was 90.8% and 93.9 %, respectively. The incidence of grades 1-2 acute reactions in skin, mucosa, salivary gland and pharynx-esophagus was 92.8%, 89.8%, 96.9% and 98%, respectively. The incidence of grades 3-4 acute reactions in skin, mucosa, salivary gland and pharynx-esophagus was 4.1%, 7.1%, 0% and 2%, respectively. The single fraction was 2.25 Gy, the total dose was 67.5 Gy （30 F/40 d）, the BED of the modified dose fraction patterns was 62.9 Gy, the single BED was 2.5 Gy, and the total BED was 72 Gy for tumor tissue. The single BED was 2 Gy and the total BED was 70 Gy for advanced reactions in normal tissue. Conclusion The short-term curative effect of modified dose fractionation patterns of intensity-modulated radiotherapy on NPC is rather good with few adverse reactions and a shorter total treatment time which thus decreases the economic cost of patients. However, its long-term curative effect is yet to be further observed.