|Classification and external resources|
|Specialty||Gastroenterology, Surgery, Oncology|
|ICD-10||K52.0, K62.7and K92.0|
Radiation enteropathy or radiation enteritis is a syndrome that may develop following abdominal or pelvic radiation therapy for cancer. Many affected people are cancer survivors who had treatment for cervical cancer or prostate cancer; it has also been termed pelvic radiation disease with radiation proctitis being one of the principal features.
Signs and symptoms
- rectal bleeding
- diarrhea and steatorrhea
- other defecation disorders including fecal urgency and incontinence.
- nutritional deficiencies and weight loss
- abdominal pain and bloating
- nausea, vomiting and fatigue
Gastrointestinal symptoms are often found together with those in other systems including genitourinary disorders and sexual dysfunction. The burden of symptoms substantially impairs the patients' quality of life.
Nausea, vomiting, fatigue and diarrhea may happen early during the course of radiotherapy. Radiation enteropathy represents the longer-term, chronic effects which may be found after a latent period most commonly of 6 months to 3 years after the end of treatment. In some cases, it does not become a problem for 20-30 years after successful curative therapy.
A large number of people receive abdominal and or pelvic radiotherapy as part of their cancer treatment with 60-80% experiencing gastrointestinal symptoms. This is used in standard therapeutic regimens for cervical cancer, prostate cancer, rectal cancer, lymphoma and other abdominal malignancies. Symptoms can be made worse by the effects of surgery, chemotherapy or other drugs given to treat the cancer. Improved methods of radiotherapy have reduced the exposure of non-involved tissues to radiation, concentrating the effects on the cancer. However, as the parts of the intestine such as the ileum and the rectum are immediately adjacent to the cancers, it is impossible to avoid some radiation effects. Previous intestinal surgery, obesity, diabetes, tobacco smoking and vascular disorders increase the chances of developing enteropathy.
Acute intestinal injury
Early radiation enteropathy is very common during or immediately after the course of radiotherapy. This involves cell death, mucosal inflammation and epithelial barrier dysfunction. This injury is termed mucositis and results in symptoms of nausea, vomiting, fatigue, diarrhea and abdominal pain. It recovers within a few weeks or months.
Long-term effects of radiation
The delayed effects, found 3 months or more after radiation therapy, produces pathology which includes intestinal epithelial mucosal atrophy, vascular sclerosis, and progressive fibrosis of the intestinal wall, among other changes in intestinal neuroendocrine and immune cells and in the gut microbiota. These changes may produce dysmotility, strictures, malabsorption and bleeding. Problems in the terminal ileum and rectum predominate.
Multiple disorders are found in patients with radiation enteropathy, so guidance including an algorithmic approach to their investigation has been developed. This includes a holistic assessment with investigations including endoscopies, breath tests and other nutritional and gastrointestinal tests. Full investigation is important as many cancer survivors of radiation therapy develop other causes for their symptoms such as colonic polyps, diverticular disease or hemorrhoids.
- Small intestinal bacterial overgrowth
- Exocrine pancreatic insufficiency
- Bile acid diarrhea
- Urinary urgency
- Sexual dysfunction
Prevention of radiation injury to the small bowel is a key aim of techniques such as brachytherapy, field size, multiple field arrangements, conformal radiotherapy techniques and intensity-modulated radiotherapy. Medications including ACE inhibitors, statins and probiotics have also been studied and reviewed.
In people presenting with symptoms compatible with radiation enteropathy, the initial step is to identify what is responsible for causing the symptoms. Management is best with a multidisciplinary team including gastroenterologists, nurses, dietitians, surgeons and others.
Medical treatments include the use of hyperbaric oxygen which has beneficial effects in radiation proctitis or anal damage. Nutritional therapies include treatments directed at specific malabsorptive disorders such as low fat diets and vitamin B12 or vitamin D supplements, together with bile acid sequestrants for bile acid diarrhea and possibly antibiotics for small intestinal bacterial overgrowth.
Endoscopic therapies including argon plasma coagulation have been used for bleeding telangiectasia in radiation proctitis and at other intestinal sites, although there is a rick of perforation. Sucralfate enemas have benefits in proctitis.
Surgical treatment may be needed for intestinal obstruction, fistulae, or perforation, which can happen in more severe cases. These can be fatal if patients present as an emergency, but with improved radiotherapy techniques are now less common.
Optimal treatment usually produces significant improvements in quality of life.
An increasing number of people are now surviving cancer, with improved treatments producing cure of the malignancy (cancer survivors). There are now over 14 million such people in the US, and this figure is expected to increase to 18 million by 2022. More than half are survivors of abdominal or pelvic cancers, with about 300,000 people receiving abdominal and pelvic radiation each year. It has been estimated there are 1.6 million people in the US with post-radiation intestinal dysfunction, a greater number than those with inflammatory bowel disease such as Crohn's disease or ulcerative colitis.
- Hauer-Jensen M, Denham JW, Andreyev HJ (2014). "Radiation enteropathy--pathogenesis, treatment and prevention". Nat Rev Gastroenterol Hepatol 11 (8): 470–9. doi:10.1038/nrgastro.2014.46. PMC 4346191. PMID 24686268.
- Stacey R, Green JT (2014). "Radiation-induced small bowel disease: latest developments and clinical guidance". Ther Adv Chronic Dis 5 (1): 15–29. doi:10.1177/2040622313510730. PMC 3871275. PMID 24381725.
- Fuccio L, Guido A, Andreyev HJ (2012). "Management of intestinal complications in patients with pelvic radiation disease". Clin. Gastroenterol. Hepatol. 10 (12): 1326–1334.e4. doi:10.1016/j.cgh.2012.07.017. PMID 22858731.
- Andreyev HJ, Davidson SE, Gillespie C, Allum WH, Swarbrick E (2012). "Practice guidance on the management of acute and chronic gastrointestinal problems arising as a result of treatment for cancer". Gut 61 (2): 179–92. doi:10.1136/gutjnl-2011-300563. PMC 3245898. PMID 22057051.
- Carr KE (2001). "Effects of radiation damage on intestinal morphology". Int. Rev. Cytol. 208: 1–119. PMID 11510566.
- Andreyev HJ, Muls AC, Norton C, Ralph C, Watson L, Shaw C, Lindsay JO (2015). "Guidance: The practical management of the gastrointestinal symptoms of pelvic radiation disease". Frontline Gastroenterol 6 (1): 53–72. doi:10.1136/flgastro-2014-100468. PMC 4283714. PMID 25580207.
- Min M, Chua B, Guttner Y, Abraham N, Aherne NJ, Hoffmann M, McKay MJ, Shakespeare TP (2014). "Is "pelvic radiation disease" always the cause of bowel symptoms following prostate cancer intensity-modulated radiotherapy?". Radiother Oncol 110 (2): 278–83. doi:10.1016/j.radonc.2013.11.012. PMID 24412017.
- Gibson RJ, Keefe DM, Lalla RV, Bateman E, Blijlevens N, Fijlstra M, King EE, Stringer AM, van der Velden WJ, Yazbeck R, Elad S, Bowen JM (2013). "Systematic review of agents for the management of gastrointestinal mucositis in cancer patients". Support Care Cancer 21 (1): 313–26. doi:10.1007/s00520-012-1644-z. PMID 23142924.
- Bennett MH, Feldmeier J, Hampson N, Smee R, Milross C (2012). "Hyperbaric oxygen therapy for late radiation tissue injury". Cochrane Database Syst Rev 5: CD005005. doi:10.1002/14651858.CD005005.pub3. PMID 22592699.
- Denton A, Forbes A, Andreyev J, Maher EJ (2002). "Non surgical interventions for late radiation proctitis in patients who have received radical radiotherapy to the pelvis". Cochrane Database Syst Rev (1): CD003455. doi:10.1002/14651858.CD003455. PMID 11869662.
- Regimbeau JM, Panis Y, Gouzi JL, Fagniez PL (2001). "Operative and long term results after surgery for chronic radiation enteritis". Am. J. Surg. 182 (3): 237–42. PMID 11587684.
- Siegel R, DeSantis C, Virgo K, Stein K, Mariotto A, Smith T, Cooper D, Gansler T, Lerro C, Fedewa S, Lin C, Leach C, Cannady RS, Cho H, Scoppa S, Hachey M, Kirch R, Jemal A, Ward E (2012). "Cancer treatment and survivorship statistics, 2012". CA Cancer J Clin 62 (4): 220–41. doi:10.3322/caac.21149. PMID 22700443.
- Movsas B, Vikram B, Hauer-Jensen M, Moulder JE, Basch E, Brown SL, Kachnic LA, Dicker AP, Coleman CN, Okunieff P (2011). "Decreasing the adverse effects of cancer therapy: National Cancer Institute guidance for the clinical development of radiation injury mitigators". Clin. Cancer Res. 17 (2): 222–8. doi:10.1158/1078-0432.CCR-10-1402. PMID 21047979.