Radiation enteropathy

Radiation enteropathy
Radiation enteropathy
Other names	Radiation enteritis, pelvic radiation disease
Specialty	Gastroenterology, surgery, oncology
Symptoms	Diarrhea, abdominal pain, nausea, vomiting, anorexia and malaise
Complications	Stricture formation, malabsorption
Usual onset	Acute: several weeks after radiation ; Chronic: 8–12 months after radiation

Radiation enteropathy is a

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.^[3]

Signs and symptoms

People who have been treated with

radiotherapy for pelvic and other abdominal cancers frequently develop gastrointestinal symptoms.^[3]^[1]^[2]

These include:

rectal bleeding
diarrhea and steatorrhea
other defecation disorders including fecal urgency and incontinence.
nutritional deficiencies and weight loss

abdominal pain and bloating
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.^{[citation needed}

]

Nausea, vomiting, fatigue, and diarrhea may happen early during the course of radiotherapy. Radiation enteropathy represents the longer-term, chronic effects that 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.[1]

Associated conditions

Small intestinal bacterial overgrowth^[4]
Exocrine pancreatic insufficiency
Bile acid diarrhea
Urinary urgency
Sexual dysfunction

Causes

A large number of people receive abdominal and or pelvic

rectal cancer, anal 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.^[4] 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.^[1] Previous intestinal surgery, obesity, diabetes, tobacco smoking and vascular disorders increase the chances of developing enteropathy.^[1]

Pathology

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.^[1]^[5] It recovers within a few weeks or months.

Long-term effects of radiation

The delayed effects, found 3 months or more after radiation therapy, produce pathology which includes

dysmotility, strictures, malabsorption and bleeding. Problems in the terminal ileum and rectum predominate.^{[citation needed}

]

Diagnosis

Multiple disorders are found in patients with radiation enteropathy, so guidance including an algorithmic approach to their investigation has been developed.

hemorrhoids.^[7]

Prevention

Prevention of radiation injury to the small bowel is a key aim of techniques such as

probiotics have also been studied and reviewed.^[2]^[8]

Treatment

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.

bile acid diarrhea and possibly antibiotics for small intestinal bacterial overgrowth.^[2] Probiotics have all been suggested as another therapeutic avenue.^[10]

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.^[2]

Surgical treatment may be needed for

intestinal obstruction, fistulae, or perforation, which can happen in more severe cases.^[11] These can be fatal if patients present as an emergency, but with improved radiotherapy techniques are now less common.^{[citation needed}

] A systematic review has found there is some promising evidence for non-surgical interventions for late rectal damage, however due to low quality evidence no conclusions could be drawn.[12] Optimal treatment usually produces significant improvements in quality of life.^[3]

Prevalence

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.^[13] 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.^[1]