Radiation Proctitis

Radiation proctitis is injury to the rectal mucosa from pelvic radiotherapy (prostate, cervical, rectal, uterine, bladder cancers).

• Acute proctitis occurs in about 75% during or soon after treatment and is self limiting.
• Chronic proctitis affects 5 to 20%, emerging 3 months to years later, from ischaemia, mucosal telangiectasia and fibrosis.
• Risk factors: dose over 70 Gy, brachytherapy, anticoagulation, diabetes, hypertension, HIV, inflammatory bowel disease, prior pelvic surgery, concurrent chemotherapy.
• Complications: bleeding with iron deficiency anaemia, stricture, ulcer, fistula (rectovaginal, rectovesical), incontinence, perforation.

• Rectal bleeding (most common), mucus discharge, tenesmus, urgency, frequency, pain, incontinence.
• Chronic bleeding may cause symptomatic anaemia.
• Fistula presents with passage of air, stool or urine per vagina or per urethra.
• Late symptoms should prompt consideration of recurrence or second malignancy.

• Sigmoidoscopy or colonoscopy: friable mucosa, telangiectasia, pallor, ulceration, stricture. Biopsy is generally avoided in telangiectatic mucosa because of bleeding and poor healing, unless malignancy is suspected.
• Full blood count and ferritin.
• MRI pelvis or CT for stricture, fistula, tumour recurrence.
• Exclude infection, ischaemic colitis, inflammatory bowel disease and recurrent cancer.

• Acute: supportive, loperamide, hydration, topical mesalazine, or hydrocortisone enema/suppository. Short courses of sucralfate enema 3 g in 15 mL twice daily.
• Chronic mild bleeding: sucralfate enema 3 g twice daily for 4 to 8 weeks, metronidazole 400 mg three times daily for 8 weeks, oral sodium butyrate, short chain fatty acid enemas, stool softeners (macrogol), correction of anaemia with oral or IV iron.
• Persistent bleeding: endoscopic argon plasma coagulation (30 to 50 W, 1 to 2 L/min, 2 to 3 sessions, success over 80%). Radiofrequency ablation and cryotherapy are alternatives.
• Formalin 4% topical application (soaked gauze, 5 to 10 minutes) for refractory bleeding, with risk of pain, stricture and necrosis.
• Hyperbaric oxygen (30 to 40 sessions at 2.0 to 2.4 atmospheres, 90 minutes) for refractory disease.
• Strictures: endoscopic dilation. Fistula or intractable disease: diverting colostomy, then resection and reconstruction when healed.
• Stop anticoagulants where safe. Surveillance for secondary malignancy.