后程三维适形大分割放疗加化疗治疗局部晚期非小细胞肺癌的临床探讨

 目的　探讨后程三维适形大分割放疗（LCHDRT）加化疗治疗局部晚期非小细胞肺癌（NSCLC）的疗效和患者的耐受性。方法　73 例患者于治疗前4周行常规分割放射治疗40 Gy，照射野包括原发病灶、同侧肺门和纵隔淋巴引流区。后2周主要针对肿瘤局部行LCHDRT，24～30 Gy，4～5 Gy／次，3次／周，肿瘤的α／β＝10 Gy，原发病灶总总生物等效剂量为81.6～93 Gy。≥95 %等剂量线包绕计划靶体积并以此为处方线。锁骨上淋巴结转移者用X线和β线混合治疗65～70 Gy。放疗中第1 周和第5周，采用长春瑞滨（NVB）25 mg／m2，第1、8天静脉推注，顺铂（DDP）30 mg，第1天至第 3天静脉滴注。结果　白细胞减少总发生率为72.6 %（53 ／ 73）； 放射性肺炎发生率为46.6 %（34 ／ 73），29例V20≤25 %患者中，仅5例（17.2 %）发生了1级放射性肺炎，而44例V20＞25 %且≤30 %患者中，共29例 （65.9 %）发生了1～3级放射性肺炎（χ2＝16.63，P＜0.01）。放射性食管炎、恶心、发热、血红蛋白减少和血小板减少等多为1～2级急性反应，经对症处理后，全部患者均能耐受计划治疗。4例年龄超过70岁以上的患者并发了3级急性放射性肺炎。后期放射性损伤以肺纤维化为主，占34.3 %（25／73）。完全缓解率为17.8 %（13／73），部分缓解率为69.9 %（51／73），总有效率为87.7 %（64／73）。1、3、5年局控率分别为82.2 %（60／73）、60.3 %（44／73）、50.7 %（37／73），生存率分别为57.5 %（42／73）、23.3 %（17／73）、13.7 %（10／73）。结论　LCHDRT加化疗治疗局部晚期NSCLC有提高总生存率的趋势，但合理的时间-剂量-分割模式仍需深入探讨。

Late-course high-dose radiotherapy combined with concurrent chemotherapy for locally advanced non-small cell lung cancer

Objective　To evaluate the effect and patient's tolerance on late-course high-dose radiotherapy (LCHDRT) combined with concurrent chemotherapy for locally advanced non-small cell lung cancer(NSCLC). Methods　73 NSCLC patients were entered into this study from May 2000 to May 2006. The treatment regime consisted of conventional radiotherapy first (40 Gy, 20 f, 4 w), followed by LCHDRT (24-30 Gy, 6 f, 2 w, tumor α/β = 10 Gy, BED = 81.6-93 Gy) combined with concurrent chemotherapy. Conventional irradiation field encompassed the primary lesion, hilum of lung and mediastinal lymph drainage region. LCHDRT focused on the primary lesion only, with ≥95 % isodose curve covering the planning target volume (PTV) and the target dose was prescribed to PTV. Supraclavicular metastases lymph node was treated by 6 MV X-ray and electron beam to a total dose of 65-70 Gy. Chemotherapy regime consisted of vinorelbine (25 mg/m2, d1, 8 iv) and cisplatin (30 mg/d, d1-3, iv gtt) in the lst and 5th weeks. Results　Leukopenia and radiation-induced pneumonitis, as shown by the WHO staging system were the most common acute toxicities. In V20≤25 %, 17.2 % (5/29) patients happened radiation-induced pneumonitis only. But in V20 ＞ 25 % and ≤ 30 %, 65.9 % (29/44) happened radiation-induced pneumonitis (χ2 = 16.63, P < 0.01). It showed that patients accompany increment of V20, the happening rate of radiation-induced pneumonits probability was increased. The other acute toxicities such as nausea, fever, radiation-induced esophagitis, hemoglobin decrease and thrombocytopenia were mainly grade 1 or 2. After symptomatic treatment, all patients completed the planned treatment without interruption except 4 patients above 70 old years of grade 3 radiation-induced pneumonitis. Late lung radio-fibrosis was 34.3 % (25/73). Before the end of the second month after treatment, the complete response (CR) and partial response (PR) rates were 17.8 % (13/73) and 69.9 % (51/73), respectively, with CR+PR rate of 87.7 %. The 1-, 3-, 5- year local control and overall survival rates as monitored by the χ2 test method were 82.2 %, 60.3 %, 50.7 % and 57.5 %, 23.3 %, 13.7 %, respectively. Conclusion　LCHDRT combined with concurrent chemotherapy shows a promising results, but the rational time-dose-fraction model still need further observation.