Clinical Outcome and Risk Factors of Chronic Radiation Proctitis Following Pelvic Radiation Therapy

Background/Aim: Pelvic radiation therapy (RT) is a common treatment for malignancies, including gynecological, genitourinary, and lower gastrointestinal tract cancers. However, chronic radiation proctitis (RP) is an unavoidable side effect, and its clinical presentation varies from asymptomatic to potentially life-threatening. This study evaluated the clinical characteristics and risk factors of chronic RP. Patients and Methods: Patients with chronic RP (212) following RT for various pelvic cancers between January 2015 and December 2021 were enrolled. Clinical characteristics of RP were analyzed retrospectively. Severity was graded according to the Radiation Therapy Oncology Group (RTOG) modified rectal toxicity score and Vienna rectoscopy score (VRS), and risk factors were statistically analyzed. Results: The most common pelvic cancer observed was cervical cancer. The patients received three-dimensional conformal RT (3D-CRT), intensity-modulated RT, or a combination of 3D-CRT and intracavitary RT (ICR). Rectal bleeding occurred in 70 (33.0%) patients. Previous abdominopelvic surgery and total radiation dose significantly correlated with the RTOG score and VRS. Previous abdominopelvic surgery, ICR, and total radiation dose were associated with chronic hemorrhagic RP. All patients with chronic hemorrhagic RP were treated with argon plasma coagulation (APC). 91.4% of cases required 1-3 APC sessions to resolve the bleeding, with a mean of 1.7 sessions. Conclusion: Our results showed that previous abdominopelvic surgery and total radiation dose were significant risk factors related to chronic RP, while total radiation dose was related to chronic hemorrhagic RP. We also showed that APC was effective and safe for chronic hemorrhagic RP.