不同能量X线全盆外照射对宫颈癌患者腹盆部皮肤萎缩和皮下组织纤维化的影响

Effect on dermal atrophy and subcutaneous fibrose caused by different high energy X-ray during external beam radiotherapy for cervical cancer patients

目的观察不同能量X线全盆外照射加^252Cf中子腔内照射治疗宫颈癌对5年总体生存率、局部控制率、早晚期并发症发生率，特别是腹盆部皮肤萎缩、皮下组织纤维化等晚期放射反应的影响。方法选择1999年1月至2002年11月115例未曾接受过任何治疗的临床分期为Ⅱ～Ⅳ期宫颈癌患者作为研究对象。治疗方案：所有患者均采用6-MV或8-MV的X线全盆外照射加^252Cf中子后装的治疗方式，其中使用6-MV加速器照射70例（6-MV组），使用8-MV加速器照射45例（8-MV组）。宫旁A点总剂量29～49Gy（1次／周，7～11Gy／次，共进行3～4次，治疗间歇穿插全盆外照射）。全盆外照射采用前后对穿野常规照射。对穿野照射20～36Gy后，盆腔野中央屏蔽挡铅4cm，继续照射至44～52Gy。全盆外照射及^252Cf中子腔内照射后，如患者宫旁仍有肿瘤侵犯，宫旁小野补量8～12Gy。所有患者均随访5年以上。观察所有患者的5年总体生存率、局部控制率、早晚期并发症发生情况，重点观察腹盆部皮肤萎缩和皮下组织纤维化等晚期放射反应及分级。结果全部患者5年总体生存率、局部控制率分别为79．2％（91／115）、82．6％（95／115），其中6-MV组患者的5年总体生存率、局部控制率分别为75．7％（53／70）、77．1％（54／70），低于8-MV组（84．4％（38／45）、88．8％（40／45）]，但两组差异无统计学意义（P〉0．05）。全部患者大于G2级的晚期放射性膀胱炎发生率为3．5％（4／115），其中6-MV组为4．3％（3／70），高于8-MV组[2．2％（1／45）]，但两组差异无统计学意义（P〉0．05）。大于G2级晚期放射性直肠炎发生率为6．96％（8／115），其中6-MV组为8．6％（6／70），高于8-MV组[4．4％（2／45）]，但两组差异无统计学意义（P〉0．05）。皮肤早期反应较重的主要是侵犯阴道下1／3的Ⅲ期患者，6-MV组稍重。皮肤晚期反应中，6-MV组G2级皮下组织纤维化发生率为44．3％（31／70），明显高于8-MV组[6．7％（3／45）]，差异有统计学意义（P〈0．01）。皮肤片状萎缩等于G2级放射反应的发生率为35．6％（25／70），明显高于8-MV组[4．4％（2／45）]，差异有统计学意义（P〈0．01）。结论虽然6-MV和8-MV两组患者外照射后的5年总体生存率、局部控制率、晚期放射性膀胱和直肠炎发生率均没有明显差别，但8-MV组5年总体生存率、局部控制率均高于6-MV组，晚期放射性膀胱和直肠炎发生率低于6MV组。特别是8-MV组患者腹盆部皮肤萎缩和皮下组织纤维化发生率明显低于6-MV组，所以盆腔外照射应使用8-MV以上的高能X线。

Objective To observe the outcome,late complication rate in bladder, rectum and skin of the combination californium- 252 brachytherapy and external beam radiotherapy（EBRT） with different high energy X-ray during advanced cervical cancer treat- ment. Methods From January 1999 to December 2002,115 cervical cancer patients who had not any treatment were staged into Ⅱ a - Ⅳa：20,45,22,18,10 respectively, by the standard of FIGO. Cf-252 brachytherapy and EBRT were implemented in all patients. Cf-252 brachytherapy was delivered with 8 - 11Gy/fraction/week, the total dose of reference point A was 29 - 49 Gy in 3 - 4fractions. The whole pelvises were irradiated with 6-MV or 8-MV X-ray,200 cGy/fraction,4 times per week. The total dose of external beam radiotherapy was 44 to 72Gy（the middle of whole pelvic field was blocked for 4cm width after 20-36Gy）. The Kaplan Meier method was used to calculate 5 years overall survival rate,local control rate and late complication rate in bladder, rectum and skin. All patients were followed up for more than 5 years. Results The 5 years overall, local control rate for all patients were 79.2%（91/115）and 82. 6% （95/115） respectively. But they were not significantly different for 8-MV group[84. 4% （38/45）, 88.8%（40/45）] and 6-MV group[75.7%（53/70）,77. 1%（54/70）,P〉0.05]. The late complication rate was 3.5%（4/115） for cystitis, but they were not significantly different for 8-MV group[2.2 % （1/45）] and 6-MV group[4.3 % （3/70）, P〉0.05]. The late complication rate was 6.96 % （8/115） for proctitis, but they were also not significantly different for 8-MV group[4.4 % （2/45）] and 6-MV group[8.6%（6/70） ,P〉0.05]. The late complication rate for subcutaneous fibrose were 44.3%（31/70）in 6-MV group and 6.7 %（3/45） respectively. The late complication rates for dermal atrophy were 35.6 % （25 / 70） in 6-MV group and 4.4 % （2/45） respectively. All of them were significantly different （P〈0.01）. Conclusion Although it was no significant difference for the 5 years overall survival rate,local control rate and late complication rate in bladder and rectum between 6-MV and 8-MV group,8-MV group was higher than 6-MV group for the 5 years overall survival rate,local control rate. Moreover, 8-MV group was lower than 6-MV group for late complication rate in bladder and rectum. Especially for subcutaneous fibrose in skin, they were significantly difference. It should use more than 8-MV X-ray during EBRT due to above mentioned reseasons.