Radiation enteritis and colitis - intestinal damage due to exposure to the body of ionizing radiation.
The incidence of intestinal radiation damage is from 2 to 20% of all cases of radiation therapy for pelvic or abdominal tumors.
Radiation damage to the intestine develops most often in patients receiving radiation therapy for tumors of the pelvis (rectum, uterus, cervical canal, prostate, bladder and testicles) or lymph nodes. The small intestine is more sensitive to radiation than the large intestine, but less exposed to the risk of radiation damage, as it is more mobile than fixed parts of the intestine. The rectum is vulnerable to damage due to its fixed position within the pelvis and close proximity to the site of treatment. The lesion often has a segmental character - rectum or sigmoid colon, a segment of the small intestine.
Risk factors for chronic radiation-induced enteritis and colitis are advanced age, concomitant chemotherapy, the presence of inflammatory bowel disease (IBD), poor radiation equipment, and existing postoperative adhesions. The epithelium of the small and large intestines is especially susceptible to acute radiation damage. As a result of the death of the epithelium of the villi of the small intestine is shortened, the number of dividing cells quickly increases in the crypts. In his own plate signs of inflammation appear in the form of pronounced neutrophilic infiltration. In the colon, inflammation and atrophy of the mucous membrane, as a rule, lead to the development of acute colitis and proctitis. Acute damage after completion of radiotherapy may result in complete restoration of the mucous membrane.
Massive radiation can cause enteritis and colitis after weeks, and even years after the end of radiation therapy. The threshold dose for delayed damage to mucosal tissue is in the range of 40 Gy. It is not associated with acute damage to the mucous membrane, but is caused by radiation damage to small vessels: the development of endarteritis, the formation of microthrombus and the development of intestinal ischemia. This leads to fibrosis, edema of the intestinal wall with the formation of a narrowing, obstruction of the vessels of the mucous membrane with its secondary damage. Radiation enteritis is characterized by slowing of motility with an excessive growth of microbial flora, a decrease in the absorption of bile acids, an increase in intestinal permeability and lactose malabsorption. In severe cases, pseudo-intestinal syndrome may develop. In addition, with radiation enteritis and colitis, strictures and fistulas are often formed.
In case of acute radiation damage to the intestine, edema, hyperemia, and increased vulnerability of the mucous membrane occur. Histological examination reveals an acute inflammatory reaction characterized by cellular, mainly neutrophilic, infiltration and accumulation of eosinophils in crypts.
All layers of the intestinal wall, including the serous membrane, are usually affected. When this occurs, hyalinosis of the vascular wall, thrombi are formed in the arteries and veins, which lead to the development of ischemia or tissue hypoxia, which is manifested by a thickening of the serous membrane, the development of fibrosis of the muscular layer, as well as atrophy and ulceration of the mucous membrane. Radiation enteritis is characterized by the development of hyporegenerative atrophy of the mucous membrane of the small intestine, i.e. atrophy of the integumentary epithelium, the absence of regeneration zones in crypts, a decrease in their depth. With radial colitis, ulcerative-destructive changes occur.
The first symptoms of the disease may appear in the period from 6 months. up to 30 years after the end of radiation therapy, an average of 2 years (80% of patients).
Severe radiation lesions of the intestine are possible only with acute radiation sickness. In these cases, severe diarrhea develops with rapidly progressive impaired absorption syndrome and exudative enteropathy.
The clinical picture of chronic radiation enteritis is due to manifestations of dysbiosis (excessive bacterial growth) of the small intestine and is characterized by such symptoms as:
- macrocytic anemia (B12 deficient),
- convulsions / osteomalacia,
- peripheral neuropathy,
- abdominal pains
- night blindness
- weight loss.
The clinical picture of chronic radiation colitis and proctitis is caused by ulcerative-destructive changes of the mucous membrane and is similar to that of ulcerative and ischemic colitis. Symptoms:
- colic pains in the abdomen or rectum,
- imperative urges
- constipation due to the development of stricture,
- mucus secretion
- blood in the stool or bleeding.
The most severe complications are massive bleeding, the development of pronounced strictures and the formation of fistulas between the colon and other organs, such as the vagina.
The diagnosis of radiation enteritis and colitis is based on a history of radiation exposure. A thorough clinical examination with the exception of other causes usually allows you to make this diagnosis.
Diagnosis of radiation enteritis, in addition to history, implies a complete and consistent visualization of the upper GI tract. Using fluoroscopy of the stomach with inspection of the small intestine or enterography, the extent of the lesion is assessed and the presence of strictures or fistulas is determined. Abdominal CT scan is useful for avoiding metastases, abscesses and fluid accumulation in the abdomen.
H2 respiratory tests using lactose and lactulose as a substrate are used to diagnose lactose intolerance and excessive bacterial growth. The test with 14C or 13C-glycocholate - to determine excess bacterial growth, bile and fat malabsorption. 14C xylose breath test - to verify excess bacterial growth. Serum folate levels may be high due to its synthesis by bacteria.
The main diagnostic method, assessing the severity and extent of radiation colitis is a colonoscopy. The endoscopic picture is usually characterized by various combinations of ulceration, inflammatory changes, atrophy of the mucous membrane, narrowing of the intestinal lumen and telangiectasias. The morphological study of biopsy specimens of the mucous membrane of the colon has no diagnostic value, since the surface changes are nonspecific.
Irrigoscopy verifies the length and location of the stricture and fistula. At the same time, the following changes can be detected: a decrease or absence of haustrations, smoothing of the mucosal surface, ulceration and formation of fistulas in the affected segments of the intestine, narrowing of its lumen.
Radiation enteritis should be differentiated from diseases of the small intestine, which occur with impaired absorption. Differential diagnosis is not difficult, if there is information about previous radiation sickness and radiation. Unlike diseases with primary disorders of absorption (celiac disease, primary lactase deficiency), hyporegenerative atrophy of the mucous membrane of the small intestine is observed with radiation enteritis. For radiation injuries of the colon, differential diagnosis is carried out with IBD, ischemic colitis and tumors.
Standard therapy for the treatment of radiation enteritis and colitis has not been developed. The choice of therapy is based on the nature and severity of the symptoms.
Drug treatment of radiation enteritis is represented by symptomatic therapy, correction of nutritional status and hydration. A low protein diet is recommended for patients with stricture. Treating overgrowth of bacteria can normalize vitamin B12 absorption and anemia. It is necessary to combat diarrhea, to carry out activities aimed at restoring absorption in the small intestine, normalizing intestinal motility, and other therapeutic blocks.
The basis of drug therapy for severe chronic radiation enteritis is complete parenteral nutrition, especially in the presence of an extended stricture and short bowel syndrome. When switching to a normal diet, the following products should be avoided: milk and dairy products, except buttermilk, yogurt and cheese, bran bread and cereals, nuts (including coconut), dried fruits, seeds, fried or fatty foods, fresh fruit and raw vegetables, roasted corn, chips, spices, chocolate, coffee, tea, soft drinks containing caffeine, alcohol. You must take at least 3 liters of fluid per day. Adding nutmeg to the diet reduces GI motility.
In treatment radiation colitis use drugs with anti-inflammatory action. In the case of resistant radiation colitis, hyperbaric oxygenation is used.
Bleeding with radiation proctitis endoscopic argon plasma coagulation is most effectively eliminated. Complications include the formation of rectal ulcers in almost every second patient. These ulcers are usually asymptomatic and do not interfere with re-treatment. No contact method allows rapid treatment of multiple common lesions.
In case of radiation proctitis, accompanied by repeated bleeding, therapy is used aimed at obtaining coagulation tissue necrosis at the site of contact.
Treatment radiation strictures is performed surgically. In the absence of signs of obstruction, it is possible to use individually selected laxatives.
Surgical treatment is associated with great technical difficulties due to the concomitant pronounced adhesions in the abdominal cavity.
Acute radiation damage to the intestine is completely reversible without specific treatment, both macroscopically and histologically. Bowel lesions can regenerate despite continued radiation. If the damage is sufficiently pronounced, it is necessary to stop the treatment, at least for a while.
In chronic radiation proctitis in 70% of patients the disease will be moderate, without the need for blood transfusions, 5% will be severe with the development of complications.
Approximately 1/3 of patients will progress progressively with radiation enteritis and will require surgical intervention.
Prevention of intestinal radiation damage is being developed. The so-called radioprotective drugs may have a protective effect on radiation.
Symptoms and treatment of radiation colitis and enterocolitis
The manifestations of this disease at the same time resembles ulcerative and ischemic colitis. It proceeds quite sharply. The mucous membrane of the body, which is sensitive to ionizing effects, loses vascular pattern, undergoes destructive atrophic changes. Strictures are possible - cicatricial narrowing - and deep ulcers.
Inflammation becomes probable at the slightest excess of 35-40 Gy exposure.
Radiation colitis is treated in approximately the same way as IBD therapy (i.e., NUC and Crohn’s disease).
For the clinical picture of the disease characteristic the following symptoms:
- pain, often localized in the anorectal and left iliac region,
- dyspeptic symptoms (nausea),
- tenesmus - false urge to defecate,
- bleeding from the anus,
- persistent diarrhea,
- weight loss.
In severe cases, dehydration with all its typical symptoms is not excluded.
The patient is prescribed drugs from the following standard list:
In the acute phase, daily intravenous administration of prednisolone or methylprednisolone is advisable for one to two weeks.
The drugs are used in different forms - in the form of rectal suppositories, enemas, tablets.
Treatment should be comprehensive and long.
The prognosis of radiation inflammation of the intestine
If the pathology is diagnosed in a timely manner, and the form of the disease is catarrhal, the outcome is likely to be prosperous.
Launched post-radiation colitis - as, indeed, almost any disease left out - gives complications. One of its most severe consequences is intestinal obstruction.
Intestinal obstruction is the indications for surgery.
Severe ulceration of the intestinal mucosa with colitis sometimes leads to perforation. Also, the progression of the disease can result in fistula formation and necrosis.
Causes of beam colitis
The etiological factor of radiation colitis is radiation exposure, which, as a rule, was obtained in the treatment of diseases of cancer, especially such as:
- prostate cancer,
- kidney tumors
- bladder cancer
- tumors of the female productive system.
Radiation damage to the intestine occurs as a result of exposure to radiation with a dose of at least 40 gray.
Radiation injuries are classified into:
- acute lesion: up to 6 weeks, many changes may be reversible,
- subacute lesion: from 6 weeks to 6 months,
- chronic disease: from 6 months to 20 years, the changes are usually irreversible.
Features - always prior radiation therapy.
The incidence of cancer is higher in the affected part of the intestine, there are three ways of development:
- random coincidence
- radiation-induced carcinogenesis,
- direct germination of cancer of the cervical canal in the intestine.
The intensity of radiation damage is influenced by the following factors:
- individual sensitivity
- the size of the exposure area,
- medical errors
- accompanying illnesses.
There are two phases of pathology development:
- The acute phase, which is characterized by necrotic damage to the mucous membrane,
- late phase, characterized by fibrosis,
- stenotic endarteritis.
Symptoms and clinical manifestations of radiation colitis:
- colitis syndrome (abdominal pain, stool disorders, mucus in the feces, bleeding, tenesmus), dyspepsia may occur.
- acute lesion, in which there are phenomena of erosive hemorrhagic proctitis and often revealed telangiectasia.
- delayed lesion, in which there are strictures, fistulas, atrophy.
Biopsy: non-specific changes.
Radiation colitis treatment
A single system of treatment of radiation colitis does not exist. Tactics of treatment depends on the symptoms of the disease, its nature and severity, the individual characteristics of the patient.
In general, the treatment is:
- anti-inflammatory therapy
- normalization of the absorption of vitamin B12,
- prevention of anemia,
- surgical removal of radiation structures.
- Bleeding is stopped by cauterization with argon.
Food with radiation colitis
A diet for radial colitis should ensure normal intestinal motility and prevent abnormal stool. Plentiful drink (not less than 3 liters per day).
- fried, fatty dishes,
- milk products,
- nuts, chocolate,
- drinks with caffeine and alcohol.
Causes of radiation (radiation) colitis and enteritis
Early radiation damage to the intestine is due to the direct effect of irradiation on the mucous membrane, which leads to the formation of nonspecific inflammation of the mucous and submucous layer (edema, hyperemia, cellular infiltration, hemorrhage), disruption of the parietal digestion process and absorption of food ingredients and water.
Late intestinal radiation injuries are mainly associated with damage to the small arterioles of the submucosal layer (hyalinosis, microvascular thrombosis), which is accompanied by chronic ischemia of the mucous membrane and submucosal layer. As a result of impaired blood supply, mucosal atrophy and reactive fibrosis gradually develop, erosions and ulcers appear, which cause intestinal bleeding. Further progression of the disease can lead to the formation of necrosis and perforation of the intestinal wall, the formation of inter-intestinal fistulas and abscesses.
Symptoms and signs of radiation (radiation) colitis and enteritis
Symptomatology is non-specific and resembles the clinical manifestations of other inflammatory diseases of the small and large intestine. It can pass without a trace.
His first sign is discomfort. Simultaneously, varying intensity of abdominal pain is noted. Erosive-desquamative and especially ulcerative-necrotic changes in the affected areas of the intestine are characterized by the presence in the intestinal discharge of blood. The intensity of blood loss is different. Radial rectitis and rectosigmoiditis are characterized by persistent pain in the left iliac region and in the rectum.
Treatment of radiation (radiation) colitis and enteritis
Drug treatment of radiation injuries of the intestine is carried out by GCS and 5-aminosalicylic acid preparations.
Prednisolone inside is prescribed in an initial dose of 20-30 mg, methylprednisolone (Urbazon) - 28 mg, followed by a decrease in dose.
A number of plants possess antispastic, enveloping, antiseptic action. They are used in the form of infusions separately or in a mixture in the ratio of 1: 1 mint, chamomile, dill, nettle, dandelion, plantain, St. John's wort, celandine, yarrow. Assign half a glass for an hour before meals inside or as microclysters.
Forecast of radiation (radiation) colitis and enteritis
Serious. However, with modern, persistent treatment, 80% of patients can achieve persistent, long-term remission of the disease. Approximately 20% of patients develop complications that require surgery. Lethal outcomes are associated with the occurrence of intestinal perforations, peritonitis, the formation of inter-intestinal fistulas and recurrent massive bleeding.
1. Earlier radiation injury - acute radiation gastritis and enterocolitis.
2. Later radiation injury - chronic radiation gastritis and enterocolitis.
Classification of radiation damage to the intestines (Bardychev MS, Tsyb A.F.)
1. In terms of:
2. By localization:
3. By the nature of the pathological process:
- necrosis of the intestinal wall.
4. Complicated forms:
- rectovaginal, rectovesical fistulae,
- cicatricial intestinal stenosis.
Types of radiation lesions of the rectal mucosa due to radiation therapy for cervical cancer:
2.1 Internal (intrinsic) - limited to the intestinal wall and are the direct result of direct radiation damage to the mucous membrane, which becomes granular, bleeding and eroded. In some cases, the only visual manifestation is mucosal bleeding.
2.2 External (unusual) manifestations of radiation injury - generalized pelvic thrombosis, followed by fibrosis and chronic granulation reaction.
Etiology and pathogenesis
Radiation damage to the intestine is most common in patients undergoing radiation therapy for tumors of the pelvis (uterus, cervical canal, prostate, testicles, rectum, bladder) or lymph nodes.
Compared with the large intestine, the small intestine is more sensitive to radiation, but less at risk of radiation damage. This is due to the fact that the small intestine is more mobile than fixed sections of the intestine. Due to its fixed position within the pelvis and close proximity to the site of radiation exposure, the rectum is vulnerable to damage. Often it has a segmental character - rectum or sigmoid colon, a segment of the small intestine.
Characteristic features of radiation enteritis:
- slowdown of motility,
- excessive growth of microbial flora,
- reducing the absorption of bile acids,
- increase in intestinal permeability, malabsorption. Malabsorption syndrome (malabsorption) - a combination of hypovitaminosis, anemia and hypoproteinemia caused by impaired absorption in the small intestine
Factors and risk groups
1. Cancer patients receiving radiation therapy (especially for older people with concomitant chemotherapy, risk 3% -17%).
2. Persons with gamma-radiation lesions in the dose range from 20 Gy with external, relatively uniform radiation (as one of the clinical forms of acute radiation sickness).
Additional to the main risk factors:
- inflammatory diseases of the pelvic organs,
- concomitant chemotherapy,
- asthenic physique,
- the history of surgical interventions on the abdominal organs or the small pelvis.
Previously intestinal injury
Develops during the first 3 months after irradiation. Clinical manifestations are non-specific and may resemble other inflammatory diseases of the small and large intestines. Earlier radiation damage can pass without a trace.
In the process of radiation therapy or after its completion, the following manifestations are possible:
- loss of appetite,
- weight loss
- diarrhea and abdominal pain.
The severity of symptoms depends on the total dose of radiation, the prevalence and localization of the pathological process.
Late intestinal radiation damage
Develops within 4-12 months after radiation therapy.
The first signs are:
- persistent constipation or frequent loose stools with false desires,
- abdominal pain of varying intensity,
- loss of appetite, constant nausea (in the majority of patients there is a shortage of body weight).
In catarrhal forms of radiation damage to the intestine, an admixture of mucus is present in the feces.
With erosive-desquamative and ulcerative-necrotic changes in the affected areas of the intestine, blood is present in the intestinal discharge. The maximum intensity of blood loss (massive intestinal bleeding) is observed in patients with necrotizing enterocolitis.
Owing to profuse bleeding or long-term detected blood admixture in the feces, patients develop iron deficiency anemia (often severe).
Manifestations of radiation rectitis and rectosigmoiditis:
- persistent pain in the left ileal region and rectum,
- intestinal bleeding, often profuse,
- Tenesmus Tenesmus - false painful urge to defecate, for example, proctitis, dysentery
The clinical picture of chronic radiation colitis and proctitis:
- ulcerative-destructive changes of the mucous membrane,
- manifestations of excessive bacterial growth.
The clinical picture of chronic radiation colitis and proctitis is similar to that in ulcerative and ischemic colitis: it develops in terms from 3 months to 30 years after the end of radiation therapy, in 80% of patients - an average of 2 years.
In about a third of patients, complications require surgical treatment.
1.1 Drug therapy of severe chronic radiation enteritis is based on full parenteral nutrition, especially in the presence of an extended stricture and short bowel syndrome.
1.2 In the transition to a normal diet, it is recommended that a diet similar to that in non-specific ulcerative colitis. It is recommended to exclude milk and dairy products (except yogurt, cheese, buttermilk), bran bread and cereals, nuts (including coconuts), dried fruits, seeds, fried or fatty foods, fresh fruits and raw vegetables, popcorn, chips from the diet. , spices, chocolate, coffee, tea, carbonated drinks, as well as drinks containing caffeine or alcohol.
1.3 You must take at least three liters of fluid per day.
2. Drug treatment
2. 1 Symptomatic therapy:
2.1.1 To eliminate diarrhea caused by bile salts, cholestyramine is prescribed, loperamide is used to reduce stool frequency and improve bile acid absorption.
In the case of resistant radiation colitis, hyperbaric oxygenation is used.
Acute radiation injury of the intestine is completely reversible (macroscopically and histologically) without special treatment. Bowel lesions can regenerate despite continued radiation. If the lesions are sufficiently pronounced, it is necessary to stop treatment, at least for a while.
In chronic radiation proctitis in 70% of patients, the disease proceeds moderately, without the need for blood transfusion, in 5% there is a severe course with the development of complications.
Radiation enteritis with atrophic and erosive-ulcerative changes in the mucous membrane of the small intestine leads to disability and is prognostically unfavorable. The progressing course of radiation enteritis, requiring surgical intervention, is observed in a third of patients.
In order to conduct an endoscopic examination of the intestine, it is necessary to pre-clean the intestine from feces. This is necessary for maximum informativeness and objectivity of the diagnostic method.
2 days before the examination, the patient should exclude from the diet raw vegetables and fruits, herbs, cereals, nuts, berries, legumes, mushrooms, flour products, soft drinks and milk. Allowed to eat lean white fish or poultry without skin, steamed, transparent vegetable broths, fermented milk products, rich biscuits, jelly, non-carbonated drinks, tea. On the day of the survey can be taken in food: broth, boiled water, tea. At a preparatory stage it is necessary to refrain from the use of preparations of iron and absorbent carbon.
In addition to diet, special methods for cleaning the intestines are also needed. The most affordable way is a cleansing enema in combination with taking castor oil. However, enemas have a number of disadvantages: low efficiency, as well as the inconvenience of the method. Therefore, doctors and patients are increasingly giving preference to special medicines, the action of which is aimed at cleansing the intestine from fecal masses. One of these drugs is MOVIPREP ®.As a rule, when taking these drugs you need to take a large amount of water (4 liters).MOVIPREP ®reduces the amount of water consumed to 2 liters, which is a significant advantage of this drug. The preparation contains ascorbate complex, which allows to reduce the consumption of the solution, but at the same time helps to increase stool volume. Polyethylene glycol 3350 (macrogol) increases the volume of fecal masses, which increases intestinal motility. Sodium sulfate has a pronounced osmotic effect, and sodium and potassium chlorides that are part of the drugMOVIPREP ®,maintain normal water and electrolyte balance.
To prepare 1 liter of the solution of the drug should be in a small amount of water to stir the contents of the bags A and B and bring the volume of the solution with water to 1 liter. The solution should be taken within 1-2 hours (1 glass every 15-20 minutes) in the evening before the test. The second liter of solution is prepared in the same way and is taken in the morning of the examination. You can also take immediately 2 liters of the solution of the drug the day before the scheduled examination. To prevent violations of water and electrolyte balance when taking the drugMOVIPREP ®need to drink an additional 1 liter of fluid. It can tea, boiled water, non-carbonated drinks and jelly.
Treatment of radiation colitis
There is no standard therapy for radiation colitis, and the choice of treatment tactics is based on the nature and severity of the symptoms.
Drug treatment is the appointment of anti-inflammatory drugs, in some cases, hyperbaric oxygenation is used (treatment with oxygen under high pressure in the pressure chambers). The most effective method of eliminating bleeding is argon plasma coagulation (cauterization with argon). Treatment of radiation strictures is performed surgically.