Mandal Abhijit, Asthana Anupam Kumar, Aggarwal Lalit Mohon
Department of Radiotherapy and Radiation Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, UP, India.
J Med Phys. 2007 Apr;32(2):68-72. doi: 10.4103/0971-6203.33244.
The purpose of this retrospective study is to report the radiotherapy treatment response of, and complications in, patients with cervical cancer on the basis of cumulative biologic effective dose (BED) and overall treatment time (OTT).Sixty-four (stage II - 35/64; stage III - 29/64) patients of cervical cancer were treated with combination of external beam radiotherapy (EBRT) and low dose rate intracavitary brachytherapy (ICBT). The cumulative BED was calculated at Point A (BED(10)); and bladder, rectal reference points (BED(2,5)) using the linear-quadratic BED equations.The local control (LC) rate and 5-year disease-free survival (DFS) rate in patients of stage II were comparable for BED(10) <84.5 and BED(10) >84.5 but were much higher for BED(10) >84.5 than BED(10) <84.5 (P< 0.01) in stage III patients. In the stage II patients, The LC rate and 5-year DFS rate were comparable for OTT <50 days and for OTT >50 days but were much higher in stage III patients with OTT < 50 than OTT >50 days (P< 0.001). It was also observed that patients who received BED(2.5) <105 had lesser rectal (P< 0.001) and bladder complications than BED(2.5) >105. Higher rectal complication-free survival (CFS(R)) rate, bladder complication-free survival (CFS(B)) rate and all-type late complication-free survival rate were observed in patients who received BED(2.5) < 105 than BED(2.5) >105.A balanced, optimal and justified radiotherapy treatment schedule to deliver higher BED(10) (>84.5) and lower BED(2.5) (< 105) in lesser OTT (< 50 days) is essential in carcinoma cervix to expect a better treatment outcome in all respects.
本回顾性研究的目的是基于累积生物等效剂量（BED）和总治疗时间（OTT），报告宫颈癌患者的放射治疗反应及并发症。64例（II期35例/64例；III期29例/64例）宫颈癌患者接受了外照射放疗（EBRT）和低剂量率腔内近距离放疗（ICBT）联合治疗。使用线性二次BED方程在A点（BED(10)）以及膀胱、直肠参考点（BED(2,5)）计算累积BED。II期患者中，BED(10) <84.5和BED(10) >84.5时局部控制（LC）率和5年无病生存率（DFS）率相当，但在III期患者中，BED(10) >84.5时的LC率和5年DFS率比BED(10) <84.5时高得多（P<0.01）。在II期患者中，OTT <50天和OTT >50天时LC率和5年DFS率相当，但在III期患者中，OTT <50天时的LC率和5年DFS率比OTT >50天时高得多（P<0.001）。还观察到，接受BED(2.5) <105的患者直肠（P<0.001）和膀胱并发症比BED(2.5) >105的患者少。接受BED(2.5) <105的患者比BED(2.5) >105的患者有更高的直肠无并发症生存率（CFS(R)）、膀胱无并发症生存率（CFS(B)）和所有类型晚期无并发症生存率。在宫颈癌中，制定平衡、优化且合理的放疗治疗计划，在较短的OTT（<50天）内给予较高的BED(10)（>84.5）和较低的BED(2.5)（<105），对于在各方面期望获得更好的治疗效果至关重要。
