Globally, prostate cancer is the most commonly diagnosed cancer in men.1 Radiation therapy remains a mainstay in the treatment of this disease. Radiation proctopathy is a common side effect of this treatment modality with an incidence in patients treated with brachytherapy alone estimated to range from 8 to 13%, and up to 21% in combination with other modalities.2 Radiation proctopathy typically presents with diarrhea, mucoid discharge, urgency, tenesmus, and bleeding. Argon plasma coagulation (APC) has become the primary therapeutic modality in the management of radiation injury. It is essential that physicians of all specialties (as well as others who care for these patients) be aware of the multiple complications of this therapy. More severe adverse events, notably rectal ulcers following APC therapy are not uncommon, with an incidence ranging from 3 to 16%.2
A sixty seven year old man with a history of prostate cancer treated with radiation therapy one year prior presented with intermittent rectal bleeding for one and a half months. Colonoscopy revealed a small area near the dentate line characterized by slightly oozing, neovascularized tissue consistent with radiation proctopathy (Image 1). This area was treated with APC with good effect. Biopsies of this area revealed hyperplastic crypts, lamina propria fibrosis, and vascular ectasias compatible with radiation injury. Three months following treatment, the patient developed recurrent rectal bleeding. A flexible sigmoidoscopy revealed a deep, non-bleeding ulcer in the rectum (Image 3). Subsequent computed tomography enterographyand magnetic resonance imaging of the pelvis demonstrated a deep rectal ulcer with abutment of a 1.5 cm peri-prostatic abscess. The patient was followed closely over the next several months, in conjunction with colorectal surgery, with serial imaging and subsequent resolution of the periprostatic abscess and cessation of rectal bleeding.
As more patients with prostate cancer are treated with radiation therapy the incidence of radiation proctopathy is increasing.3,4 Although argon plasma coagulation has been shown to be an effective therapy for this issue, providers must consider and discuss with patients the potential complications of this otherwise effective and generally welltolerated mode of treatment