Radiation enteritis

Introduction to Radiation Enteritis Radiation enteritis is a gastrointestinal complication caused by radiotherapy in pelvic, abdominal, and retroperitoneal malignancies. It can affect the small intestine, colon and rectum, so it is also called radioactive rectum, colon, and small intestine. In the early stage of intestinal mucosal cell renewal is inhibited, after the small arterial wall is swollen, occluded, causing intestinal wall ischemia, mucosal erosion, fibrosis caused by late intestinal wall, narrow or perforated intestinal lumen, abscess formation in the abdominal cavity, fistula and intestinal adhesions, etc. . basic knowledge The proportion of illness: 0.001% Susceptible people: no specific population Mode of infection: non-infectious Complications: intestinal obstruction, rectal vaginal fistula, rectal cancer

Causes of radiation enteritis

Intestinal epithelial cell proliferation is inhibited (45%)

Intestinal mucosal epithelial cells are most sensitive to radiation. The thymidine-labeled thymidine is used for cell renewal observation. It is found that the regeneration of intestinal mucosa is completed by the proliferation of undifferentiated cells located in the crypt of the intestinal gland. These cells lose their ability to divide after differentiation and gradually move to the surface of the intestinal mucosa. Radiation inhibits the proliferation of these cells, causing characteristic acute lesions in the intestinal mucosa. If the radiation dose is not excessive, mucosal damage can be restored 1 to 2 weeks after stopping the radiation therapy. Recent studies have found that the effect of multiple exposures depends on the cell cycle in which the crypt cells are exposed. Cells in the late stage of division are most sensitive to radiation, while cells synthesized in the late stage are more tolerant, at any given time. Only a portion of all proliferating crypt cells are in a certain phase of the cell proliferation cycle, so a single high-dose irradiation only kills a portion of the cells, and after a few days the cells undergo mitosis and return to normal.

Intestinal submucosal artery damage (20%)

The endothelial cells of the small arteries are very sensitive to radiation. High-dose radiation therapy causes the cells to swell, proliferate, and fibrillar, causing occlusive endarteritis and endarteritis. Therefore, intestinal wall ischemia and mucosal erosion and ulceration occur, and bacterial invasion in the intestinal tract further develops the lesion.

Intestinal wall tissue damage (20%)

Intestinal wall tissue caused by edema after extensive continuous irradiation, fibroblast proliferation in all layers of the intestinal wall, connective tissue and smooth muscle showed a transparent change, and finally led to fibrosis, intestinal stenosis, mucosal surface distortion and fracture, so the radiation produced intestine Changes in the path can vary from reversible mucosal structure to chronic fiber thickening, accompanied by ulcerated intestines, and even intestinal obstruction.

Radiation enteritis prevention

Foods that consume more cellulose or are irritating to the intestinal wall should be avoided. Foods with less slag, low fat and less gas production should be eaten. Such as carrots, spinach, etc., both intestines and vitamins. Also pay attention to keeping the anus and perineum clean and wearing loose underwear. In severe cases, radiotherapy can be suspended, and high-dose vitamins and infusions can be used to supplement various intravenous nutrition and use of adrenal cortical hormones and antibiotics to alleviate local inflammatory reactions and promote recovery.

Radiation enteritis complications Complications, intestinal obstruction, rectal vaginal and rectal cancer

Complications caused by radiation enteritis mainly include intestinal stenosis and intestinal obstruction, rectal vaginal fistula, rectal bladder spasm or back to colonic fistula, gastrointestinal ulcers and perforations, and induced knots, rectal cancer.

Radiation enteritis symptoms Common symptoms Nausea bloating diarrhea Low heat weight loss

Generally, the total dose of irradiation below 3000 rad is rarely ill. Symptoms occur when the total amount of intraperitoneal radiotherapy exceeds 4000 rad. If it exceeds 7000 rad, the incidence rate is as high as 36%. Symptoms can occur early in the treatment, shortly after the end of the treatment or months to years after treatment.

Early symptoms

Due to the reaction of the nervous system to radiation, symptoms of the gastrointestinal tract can occur early. It usually appears within 1 to 2 weeks after the start of radiotherapy. Nausea, vomiting, diarrhea, discharge of mucus or bloody stools. Those who are involved in the rectum are accompanied by urgency and weight. Long-lasting blood in the stool can cause iron deficiency anemia. Constipation is rare. Occasionally low heat. Sputum abdominal pain suggests small bowel involvement, sigmoidoscopy can be seen mucosal edema, congestion, severe cases may have erosion or ulceration.

2. Late symptoms

Symptoms that persist in the acute phase or until significant symptoms begin after 6 months to several years after the end of radiotherapy, suggest that the lesion continues and eventually develop fibrosis or stenosis. Symptoms during this period can be as early as half a year after radiotherapy, or 10 years later or even 30 years later, and more related to intestinal wall vasculitis and subsequent lesions.

(1) Colon and proctitis often occur 6 to 18 months after irradiation. Symptoms include diarrhea, blood in the stool, mucus and urgency, thin stools and progressive constipation or abdominal pain suggesting a narrowing of the intestine. Severe lesions and adjacent organs form fistulas, such as rectal vaginal fistula, feces excreted from the vagina; rectum small intestine fistula can appear in the feces mixed with feces, but also peritonitis caused by intestinal perforation, abdominal or pelvic abscess. Intestinal obstruction can occur due to narrowing of the intestine and entanglement of the intestines.

(2) Intestinal inflammation In the small intestine, severe abdominal pain, nausea and vomiting, abdominal distension, and bloody diarrhea occur when severely damaged by radiation. However, the late performance is mainly due to digestive malabsorption, accompanied by intermittent abdominal pain, steatorrhea, weight loss, fatigue, anemia and so on.

Radioactive enteritis examination

The tincture is used to check the small intestine. The lesions are often dominated by the end of the ileum. When the sputum is filled, the lumen is irregularly narrowed and pulled into an angle due to adhesion. The thorn-like shadow is formed, the intestinal wall is thickened, and the distance between the intestines is widened. Intestinal nodular filling filling defects, similar to inflammatory bowel disease, the normal feather-like mucosa of the small intestine disappeared during emptying. In recent years, mesenteric angiography has been helpful to detect small vessel lesions, and early diagnosis of radiation enteritis Differential diagnosis has a certain meaning.

Determination of intestinal absorption function: including stool fat determination, vitamin B12 and D-xylose absorption test.

There are many blood changes, such as the reduction of white blood cells and platelets.

1. Rectal examination: In the acute stage, due to inflammation and inflammation of the anorectal area, it can touch the anal sphincter spasm. The rectal wall becomes thicker and harder. The finger sleeve is blood-stained. Later patients can find rectal ulcer, rectal stenosis or.

2. X-ray examination: in the early stage of radiation enteritis, abdominal plain film can show functional intestinal obstruction, expectorant examination often shows mucosal edema, intestinal fistula dilatation and hypotonia, in the subacute phase, abdominal wall and mesentery can occur edema, edema In severe cases, mucosal folds thicken, straighten, spiked appearance, and can separate the intestinal fistula, barium enema examination, common knot in the acute phase, severe rectum in the rectum, the anterior rectal wall may be isolated Ulcer, if there is diffuse ulcer, knot, rectal wall mucosa can be needle-like (spicula- tions), late chronic radioactive enterocolitis tincture examination showed intestinal mucosal edema, intestinal fistula separation, if further fiber The lumen of the intestine is narrowed, fixed, and tubular, and the expansion of one or several segments of the intestine is poor, and the mucosal texture disappears. This X-ray is very similar to that caused by Crohn's disease or ischemic colonic disease. Intestinal stenosis, due to dysfunction of the function, functional small bowel obstruction can occur. In addition, the X-ray findings of the knot and rectal lesions include intestinal stenosis, straightening and colonic bag disappearance.

3. Colonoscopy: acute phase changes of radiation enteritis, sigmoidoscopy showed colon and rectal mucosal congestion, edema, vascular texture is unclear, and even ulcer formation, mucosal fragility, easy to contact bleeding, in radiation enteritis In the chronic phase, mucosal edema is seen, pale, granular, relatively fragile, and has obvious submucosal telangiectasia. According to the lesions seen, the radiation intestinal mucosal damage is divided into 4 degrees:

I degree: no obvious damage, mild congestion of the rectal mucosa, edema, telangiectasia, easy bleeding, and generally heal itself.

II degree: There is ulceration in the rectal mucosa, and there is a gray-white aponeurosis, necrosis of the mucosa, and sometimes mild stenosis.

III degree: The rectum is severely stenosis due to deep ulcers, and intestinal obstruction occurs. Most of them require colostomy.

IV degree: formation of rectal vaginal fistula or intestinal perforation.

Be careful when performing endoscopy to avoid intestinal perforation or bleeding.

4. Mesenteric artery angiography: small arterial injury with ischemic changes is the pathological basis of radioactive intestinal stenosis. Mesenteric arterioles are often seen on mesenteric arteries.

5. CT scan: can show non-specific changes such as thickening of the peri-rectal fibrous tissue or widening of the anterior tibiofibular space or tumor recurrence.

6. Radionuclide examination: Determination of the absorption rate of radioactive gamma-labeled cholic acid to determine the function of terminal ileum, and the determination of the permeability of macromolecules such as chromium-EDTA has certain value for the diagnosis of acute radiation enteritis, but due to these examinations The specificity is not high, and the clinical application is not extensive.

Diagnostic identification of radiation enteritis

diagnosis

The diagnosis of this disease is generally not difficult. The history of radiotherapy for pelvic, abdominal or retroperitoneal malignant tumors is one of the indispensable conditions for diagnosis. Combined with its clinical manifestations and related examinations, the diagnosis and determination of the nature and location of the lesions can be clearly determined.

Differential diagnosis

Late manifestations of radiation enteritis and recurrence and metastasis of cancer require X-ray barium examination, mesenteric angiography, endoscopy, biopsy for identification, and other diseases such as non-specific ulceration should be considered in differential diagnosis. Colitis, Crohn's disease, intestinal tuberculosis, intestinal lipid metabolism syndrome (Whipple) and the like.

1. Ulcerative colitis has no history of radiation, and pathological examination shows that crypt abscess can be identified.

2. The history of non-radioactive substance exposure in patients with pseudomembranous colitis is more than that before the use of broad-spectrum antibiotics. Generally, symptoms often appear in the process of antibiotic treatment. A few patients can appear after 1 to 10 days of withdrawal, and stool culture is difficult to distinguish. Bacillus.

3. Acute ischemic enteritis occurs mostly in elderly or oral contraceptive women. The clinical manifestations are sudden abdominal pain and blood in the stool. Colonoscopy can detect the congestion, edema, erosion and hemorrhage of the diseased intestinal mucosa, mostly transient. A small number of residual intestinal stenosis.

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