Xu Zhiyuan, Yang Li, Ma Lingyu, Liu Qin, Chang Amy Ty, Zhou Yong, Zhou Cheng, Kong Feng-Ming, Chen Longhua
Oncology Medical Center, The University of Hong Kong-Shenzhen Hospital, Shenzhen, Guangdong 518053, P.R. China.
Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.
Mol Clin Oncol. 2021 Dec;15(6):258. doi: 10.3892/mco.2021.2420. Epub 2021 Oct 15.
There is no consensus in clinical practice on the optimal bladder volume during brachytherapy. The present study aimed to assess the effect of bladder volume on radiation dose to organs at risk and tumor in cervical cancer during image-guided adaptive brachytherapy and clinical outcome. The retrospective study included patients treated at University of Hong Kong-Shenzhen Hospital between January 2015 and July 2019. Patients with International Federation of Gynecology and Obstetrics (2009) stage IB1-IVB (retroperitoneal lymph nodes metastasis only) cervical cancer treated by external beam radiotherapy with concurrent cisplatin followed by brachytherapy were assessed. A total of 421 brachytherapy insertions were analyzed. Every 83 and 90 cm (cc) increase in bladder volume led to an incremental raise of 1 Gy in bladder wall minimum dose received by the most irradiated 1 and 2 cc volumes (D1 and D2cc) of the bladder wall, respectively. An increase in bladder volume was associated with increased D1 and D2cc of bladder (both P<0.001, respectively) and rectal wall (P=0.150 and P=0.084, respectively), and decreased D1cc (P=0.003) and D2cc (P=0.001) of sigmoid wall, the maximum doses to the most minimally exposed 90 (D90) and 95% (D95) of the high risk-clinical target volume (HR-CTV; D90, P=0.010; D95, P=0.006). Patients with cumulative HR-CTV D90≤89.6 Gy had shorter median overall survival (OS) than those with cumulative HR-CTV D90>89.6 Gy (42.1 months vs. not reached, P=0.001). Patients with grade 2 acute urinary toxicity had significantly higher cumulative bladder wall D2cc than those with acute urinary toxicity<grade 2 (86.7±3.7 vs. 78.5±7.9 Gy; P=0.001). As the bladder volume increased, the dose to the bladder and rectal wall increase and dose to the sigmoid colon wall and HR-CTV decrease based on intracavitary brachytherapy. The higher dose of HR-CTV predicted better OS and the higher dose received by the bladder wall was associated with more grade 2 acute urinary toxicity.
在近距离放射治疗期间，对于最佳膀胱容量，临床实践中尚无共识。本研究旨在评估在图像引导下的适应性近距离放射治疗期间，膀胱容量对宫颈癌中危及器官和肿瘤的辐射剂量以及临床结局的影响。这项回顾性研究纳入了2015年1月至2019年7月在香港大学深圳医院接受治疗的患者。对国际妇产科联盟（2009年）IB1-IVB期（仅腹膜后淋巴结转移）宫颈癌患者进行评估，这些患者先接受外照射放疗联合顺铂同步治疗，随后接受近距离放射治疗。共分析了421次近距离放射治疗植入情况。膀胱容量每增加83和90立方厘米（cc），膀胱壁受照射最多的1立方厘米和2立方厘米体积（D1和D2cc）所接受的膀胱壁最小剂量分别增加1戈瑞（Gy）。膀胱容量增加与膀胱的D1和D2cc增加（均P<0.001）以及直肠壁的D1和D2cc增加（分别为P=0.150和P=0.084）相关，而降结肠壁的D1cc（P=0.003）和D2cc（P=0.001）降低，高危临床靶区（HR-CTV）中暴露最少的90%（D90）和95%（D95）的最大剂量降低（D90，P=0.010；D95，P=0.006）。累积HR-CTV D90≤89.6 Gy的患者中位总生存期（OS）短于累积HR-CTV D90>89.6 Gy的患者（42.1个月对未达到，P=0.001）。2级急性泌尿系统毒性患者的累积膀胱壁D2cc显著高于急性泌尿系统毒性<2级的患者（86.7±3.7对78.5±7.9 Gy；P=0.001）。基于腔内近距离放射治疗，随着膀胱容量增加，膀胱和直肠壁的剂量增加，而降结肠壁和HR-CTV的剂量降低。HR-CTV剂量越高，OS预后越好，膀胱壁接受的剂量越高，2级急性泌尿系统毒性的发生率越高。
