High-risk factors and predictive models for hemorrhagic chronic radiation proctitis

Abstract

Background Hemorrhagic chronic radiation proctitis (CRP) is the most common and stubborn complication after pelvic radiation therapy. Understanding the high-risk factors, exploring a method to predict it, and then formulating a reasonable radiotherapy plan are the keys to preventing hemorrhagic CRP. The aim of this study was to retrospectively identify potential risk factors for hemorrhagic CRP and establish a nomogram to predict the onset of hemorrhagic CRP. Methods In this retrospective study, we considered patients who received pelvic radiotherapy for cervical carcinoma from March 2014 to December 2021 at Chongqing University Cancer Hospital (Chongqing, China). Logistic regression analysis was performed to determine the factors and then a nomogram model was established. To evaluate the performance of the model, metrics such as the area under the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis were used. Results A total of 221 patients were included.125 patients diagnosed with hemorrhagic CRP by colonoscopy. The median time of diagnosis of hemorrhagic CRP was 14.45 months after pelvic radiotherapy. Age (≥ 54 years old), weight (< 52 kg) and total radiation dose (≥ 72 Gy) were identified as risk factors and then a nomogram was established to predict the onset of hemorrhagic CRP. The area under the ROC curve (AUC) values of the nomogram were 0.741 and 0.74 in the training and the validation cohort, respectively. To investigate the clinical utility of the model,decision curves and clinical impact curves were further performed. The results showed that the model was beneficial over a wide probability range from 0.25 to 0.85. and 0.74 in the training and the validation set, respectively. Conclusion In this study, we constructed and developed a nomogram for hemorrhagic CRP. The calibration curves, ROC curve analysis, and decision curves showed that the nomogram was reliable for clinical application. It may provide some evidence for radiologist to make a reasonable radiotherapy plan to preventing hemorrhagic CRP. Trial registration retrospectively registered.