| Radiation proctitis | |
|---|---|
| Other names | Radiation proctopathy, Radiation associated vascular ectasias (RAVE) |
 | |
| Endoscopic image of radiation associated vascular ectasias (RAVE) before and after therapy withargon plasma coagulation. | |
| Specialty | Gastroenterology  |
| Symptoms | Pelvic pain,tenesmus, diarrhea, urgency,hematochezia |
| Complications | Anemia,perforation, fistulae |
| Types | Acute (<3 months after radiation) and Chronic (>3 months after radiation) |
| Causes | Pelvic radiation for cancer |
| Diagnostic method | Colonoscopy orflexible sigmoidoscopy |
| Differential diagnosis | Infectious proctitis, inflammatory bowel disease |
| Treatment | Endoscopy withargon plasma coagulation, bipolar electrocautery,radiofrequency ablation |
Radiation proctitis orradiation proctopathy is a condition characterized by damage to the rectum after exposure tox-rays or otherionizing radiation as a part ofradiation therapy.[1] Radiation proctopathy may occur as acute inflammation called"acute radiation proctitis" (and the relatedradiation colitis) or with chronic changes characterized byradiation associated vascular ectasiae (RAVE) and chronic radiation proctopathy.[2][1] Radiation proctitis most commonly occurs after pelvic radiation treatment forcancers such ascervical cancer,prostate cancer,bladder cancer, andrectal cancer. RAVE and chronic radiation proctopathy involves the lowerintestine, primarily thesigmoid colon and the rectum, and was previously called chronic radiation proctitis,pelvic radiation disease andradiation enteropathy.[3]
Acute radiation proctopathy often causes pelvic pain, diarrhea,fecal urgency, and the urge to defecate despite having an empty colon (tenesmus).[4]Hematochezia andfecal incontinence may occur, but are less common.[4] Chronic radiation damage to the rectum (>3 months) may cause rectal bleeding, incontinence, or a change in bowel habits. Severe cases may lead torectal stricture oranorectal fistula formation, orsecondary malignancy.[5][4] Chronic radiation proctopathy can present at a median time of 8-12 months following radiation therapy.[4]
Acute radiation proctopathy occurs due to direct damage of the lining (epithelium) of the colon.[1] Rectal biopsies of acute radiation proctopathy show superficial depletion of epithelial cells and acute inflammatory cells located in the lamina propria.[4] By contrast, rectal biopsies of RAVE and chronic radiation proctopathy demonstrates ischemic endarteritis of the submucosal arterioles, submucosal fibrosis, and neovascularization.[4]
Where chronic radiation proctopathy or RAVE is suspected, a thorough evaluation of symptoms is essential. Evaluation should include an assessment of risk factors for alternate causes of proctitis, such asC. difficile colitis,NSAID use, and travel history.[6] Symptoms such as diarrhea and painful defecation need to be systematically investigated and the underlying causes each carefully treated.[7] Testing for parasitic infections (amebiasis,giardiasis) and sexually transmitted infections (Neisseria gonorrhoeae andherpes simplex virus) should be considered.[6] The location of radiation treatment is important, as radiation directed at regions of the body other than the pelvis (eg brain, chest, etc) shouldnot prompt consideration of radiation proctopathy.[6]
Endoscopy is the mainstay of diagnosis for radiation damage to the rectum, with eithercolonoscopy orflexible sigmoidoscopy. RAVE is usually recognized by the macroscopic appearances on endoscopy characterized by vascular ectasias.[8] Mucosal biopsy may aid in ruling out alternate causes of proctitis, but is not routinely necessary and may increase the risk of fistulae development.[6]Telangiectasias are characteristic and prone to bleeding.[3] Additional endoscopic findings may include pallor (pale appearance), edema, and friability of the mucosa.
Radiation proctitis can occur a few weeks after treatment, or after several months or years:
Several methods have been studied in attempts to lessen the effects of radiation proctitis. Acute radiation proctitis usually resolves without treatment after several months. When treatment is necessary, symptoms often improve with hydration, anti-diarrheal agents, and discontinuation of radiation.[4]Butyrateenemas may also be effective.[9][10]
In contrast, RAVE and chronic radiation proctopathy usually is not self-limited and often requires additional therapies.[4] These includesucralfate,hyperbaric oxygen therapy,corticosteroids,metronidazole,argon plasma coagulation,radiofrequency ablation andformalin irrigation.[1][3][11] The average number of treatment sessions with argon plasma coagulation to achieve control of bleeding ranges from 1 to 2.7 sessions.[4]
In rare cases that do not respond to medical therapy and endoscopic treatment, surgery may be required. Overall, less than 10 percent of individuals with radiation proctopathy require surgery.[4] In addition, complications such as obstruction and fistulae may requiresurgery.
Up to 30 percent of individuals who receive pelvic radiation therapy for cancer may develop radiation proctopathy.[4]