Pathophysiology, Natural History and Approaches to Treatment and Prevention of Radiation Proctitis

Abstract

Chronic radiation proctitis (CRP), characterized by increased frequency and urgency of defecation, fecal incontinence and rectal bleeding, is an under-estimated cause of morbidity after pelvic irradiation for urological and gynecological malignant diseases. Despite improvements in radiotherapy technology, 90% of patients have persistent long term symptoms and 50% of all patients report impairment of quality of life after pelvic radiotherapy. Research by an Australian group of clinician scientists, including prospective, longitudinal and retrospective studies as well as a randomized trial of two current approaches used for the treatment of haemorrhagic radiation proctitis over a time span exceeding two decades, have provided important insights into the prevalence, pathophysiology natural history and treatment of CRP. The findings have important implications for the management and amelioration if not prevention of CRP. Data from 4 selected studies conducted by the Australian group, each characterizing changes in anorectal function and anal sphincteric morphology, are first presented. This is followed by discussion of how the findings have led to the development of more rational therapeutic interventions for CRP and how novel approaches designed to reduce the prevalence of CRP when combined could lead to its elimination in the foreseeable future.