鼻咽癌后程加速超分割放射治疗失败因素分析

目的分析鼻咽癌后程加速超分割放射治疗后局部和远处失败的因素.方法对无远地转移的178例初治鼻咽低分化鳞癌行后程加速超分割放射治疗.原发灶采用60Co γ射线或6MV X射线,前4周1.2 Gy/次,2次/d,间隔≥6 h,5 d/周,48 Gy后改为1.5 Gy/次,2次/d,5 d/周,共2周.全程总剂量为78 Gy,60分次,6周,其中疗程超过47 d的病例均增加1 d的照射量(1.2 Gy/次或1.5 Gy/次,2次/d).颈部无淋巴结转移者做预防照射,有淋巴结转移者给予根治量照射,均为常规分割放射治疗.结果全组5年总生存率及无瘤生存率分别为72.4%和60.6%,5年鼻咽部及颈部控制率分别为88.9%和83.7%.5年远地转移率25.1%.5年内67例患者失败,其中单纯鼻咽部失败10例,颈部失败13例,远地转移31例,≥2项失败13例.单因素及多因素分析显示T3～T4期、年龄>50岁和颈动脉鞘区肿瘤完全占据是局部控制的不利预后因素.在单因素分析中有淋巴结转移是影响颈部控制率的不利因素,但多因素分析差异未达统计学意义(P>0.05).在影响远地转移的因素中,局部晚期T3～T4期或N2～N3期,男性不论在单因素还是多因素分析均显示有统计学意义.有上述不良预后因素的患者,远地转移明显增加.结论后程加速超分割放射治疗可以提高鼻咽癌患者的5年局部控制率和生存率.T3～T4期和(或)N2～N3期是影响局部控制率和远地转移率的重要不利因素.对局部晚期患者应联合其他全身方法进行治疗.

Cause of failure after late-course accelerated hyperfractionated radiotherapy

Objective To evaluate the factors that predict locoregional failure and distant metastasis after late-course accelerated hyperfractionated radiotherapy (LCAHR) for nasopharyngeal carcinoma (NPC). Methods From December 1995 to March 1998, 178 patients with untreated but diagnosed histologically as poorly differentiated squamous cell carcinoma of nasopharynx were treated by LCAHR. The radiation schedule was as follows: 1.2 Gy/Fx, twice daily, 5 days per week for four weeks, followed by 1.5 Gy, twice daily , 5 days a week in the concluding two weeks, to a total dose of 78 Gy/60Fx/6w. Patients were given additional 1.2 or 1.5 Gy x 2Fx for one day if the treatment time lasted beyond 47 days. Patients without lymph node metastasis were only given radiotherapy prophylactically to the neck only, while radical treatment was delivered to node positive groups. Results The 5-year overall survival and disease-free survival rates were 72.4% and 60.6% . The 5-year distant metastasis rate was 25.1 % . 38% (67/178) of patients developed recurrent disease: 10 at the primary site, 13 in the neck region, 31 at distant site and 13 both in the head-and-neck and distant site. Both univariate and multivariate analyses revealed that T3-T4, older than 50 years and invasion of total cervical arterial area were poor prognostic factors for the primary control. In univariate analysis, positive node was found as an adverse factor that predicted prognosis in cervical control, but the difference was not significant in the multivariate analysis. Local advanced stage (T3-T4 or N2-N3) and being male were significantly associated with high distant metastasis, in both univariate and multivariate analyses. Conclusions LCAHR can improve the 5-year primary control rate and survival rate for NPC. Patients with T3-T4 or N2-N3 disease give poor prognosis. In our study, distant metastasis ,being high, is the common cause of death in NPC. Aggressive treatment may benefit this group of patients.