Radiation proctocolitis

Background

Injury to the colon following radiation therapy most commonly affecting the sigmoid colon and rectum.
Acute ( up to three months), Chronic ( 3 months to years later)
Results in majority from radiation to the lower abdomen and pelvis as in the cases of cancers of the rectum, colon, gonads, uterus, bladder, and prostate.

Clinical Features

Uncomplicated

Diarrhea
Urgency
Mucus discharge
Tenesmus
Bleeding is more common in chronic radiation proctitis than acute radiation proctitis

Complicated

Radiation injury extending to genitourinary system
- urethral stenosis
- Cystitis
- Ureteral scarring
Radiation injury extending to small bowel
- Small bowel obstruction
- Small intestine bacterial overgrowth
- Fistulae

Differential Diagnosis

Ulcerative colitis
Crohns disease
Inflammatory Bowel Disease
CMV Colitis
Infectious/parasitic enterocolitis
Diversion colitis
Ischemic colitis
Diverticular colitis
Chronis graft-versus-host diease

Evaluation

Labs
- Stool C.diff toxin along with routine stool cultures
- Specific testing for E.coli 0157:H7
- Ova and Parasite assay including giardia
- CBC, electrolytes, albumin, ESR, CRP

Endoscopy and biopsy
- Nonspecific findings
- Pallor, friability, ulcerations, bleeding
- Telangiectatic with bleeding
- Avoid biopsy unless malignancy is suspected as facilitate fistula/non healing wound formation

Imaging
- CT if obstructive symptoms are present
- MRI if suspicion is high for radiation-induced fistulae

Management

Acute

Generally self-limited
approximately 20% of patients will need to lengthen time intervals between radiation therapy to recover
Hydration, steroids, +/- 5-aminosalicylate enema.

Chronic

Non-invasive
- Anti-inflammatories
- Sucralfate enema
- short-chain fatty acids
- Hyperbaric O2
- Antioxidants: Vitamin A, E, C.
Invasive
- Endoscopic treatment with ablation therapy : Topical formalin, Laser, Argon plasma coagulation
- Surgical resection last resort

Disposition

Treat outpatient
Severe cases that are candidates for surgery should be admitted

External Links

References

Vanneste BGL, Van De Voorde L, de Ridder RJ, Van Limbergen EJ, Lambin P, van Lin EN. Chronic radiation proctitis: tricks to prevent and treat. International Journal of Colorectal Disease. 2015;30:1293-1303. doi:10.1007/s00384-015-2289-4.

Authors: