Dose-volume analysis of predictors for acute anal toxicity after radiotherapy in prostate cancer patients

• Published in: Radiation oncology (London, England) Vol. 14; no. 1; p. 174
• Main Authors: Peng, Xingsi, Zhou, Sha, Liu, Shiliang, Li, Jibin, Huang, Sijuan, Jiang, Xiaobo, Lin, Maosheng, Huang, Shaomin, Lin, Chengguang, Qian, Chaonan, Liu, Mengzhong, He, Liru
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 10-10-2019; BioMed Central; BMC
• Subjects: Acute anal toxicity; Aged; Anal Canal - pathology; Anal Canal - radiation effects; Cancer patients; Cancer research; Care and treatment; Health aspects; Hemorrhoid; Hemorrhoids; Hemorrhoids - diagnosis; Hemorrhoids - etiology; Humans; Male; Predictive Value of Tests; Prostate cancer; Prostatic Neoplasms - pathology; Prostatic Neoplasms - radiotherapy; Radiation Injuries - diagnosis; Radiation Injuries - etiology; Radiotherapy; Radiotherapy Dosage; Radiotherapy, Conformal - adverse effects; Retrospective Studies; ROC Curve; Toxicity; China; Hemorrhoid; Radiotherapy; Acute anal toxicity; Prostate cancer
• ISSN: 1748-717X; 1748-717X
• DOI: 10.1186/s13014-019-1374-1

This study aimed to evaluate the clinical and dosimetric factors predictive of acute anal toxicity (AAT) after radiotherapy in prostate cancer (PCa) patients with or without hemorrhoids.
We analyzed data from 347 PCa patients (248 cases treated from July 2013 to November 2017 for training cohort and 99 cases treated in 2018 for validation cohort) treated with pelvic radiotherapy at a single institution. Anal canal dose-volume histogram was used to determine the prescribed dose. Univariate and multivariate analyses were used to evaluate the risk of AAT as a function of clinical and dosimetric factors.
Totally, 39.5% (98/248) and 31.3% (31/99) of the PCa patients developed AAT in training and validation cohorts, respectively. The incidence of AAT was much higher in patients with hemorrhoids than in those without hemorrhoids in both training and validation cohorts. Hemorrhoids and volume received more than 20 Gy (V20) were valuated as independent factors for predicting AAT in training cohort. Similar results were also observed in our validation cohort. The combination of hemorrhoids and high anal canal V20 (> 74.93% as determined by ROC curves) showed the highest specificity and positive predictive values for predicting AAT in both training and validation cohorts.
AAT occurs commonly in PCa patients with hemorrhoids during and after pelvic radiotherapy. Hemorrhoids and anal canal V20 are independent predictors of AAT. These factors should be carefully considered during treatment planning to minimize the incidence of AAT.