Chronic Radiation Proctitis: Tricks to Prevent and Treat
Radiation is a common part of prostate cancer treatment. There are two types of radiation therapy: brachytherapy (internal radiation), and external beam radiation. The type of radiation is typically chosen depending on the most appropriate option for the patient’s specific type of disease. There are a variety of side effects that can occur, both during radiation therapy and after. Chronic radiation proctitis is one of them.
What is radiation proctitis?
When radiation is given to areas near the rectum like the prostate, urinary tract, uterus, or cervix, there is always the possibility of radiation injury to other places like the rectum. Rectal inflammation is called proctitis, and sometimes radiation therapy to the prostate can cause proctitis.1 Chronic radiation proctitis (CRP) is a condition that occurs more than 3-6 months after the radiation therapy has ended and is present in approximately 5-20% of cancer patients.2
The likelihood of developing CRP depends on a variety of things: the total radiation therapy (RT) dose, the radiation therapy technique, how much of the rectum was irradiated, and the dose per fraction of the radiation.2 Other factors can also play a role in your likelihood of developing CRP, including diabetes, connective tissue disease or inflammatory bowel disease, smoking cigarettes, and whether you also had chemotherapy.2 Some patient risk factors have been associated with developing CRP, including having diabetes or hemorrhoids; the use of anti-coagulants, hormone therapy, or anti-hypertensive drugs; and a history of pre-radiation abdominal surgery.2
While not everyone getting radiation therapy for prostate cancer will have CRP and not everyone with these risk factors will go on to develop CRP, it’s important to be aware of the increased risk so that you can possibly reduce the likelihood of developing it – or recognize the early signs so that it can be treated sooner.
Signs and symptoms of CRP
Radiation side effects can be either acute or chronic; acute effects occur up to 3 months post-RT, and chronic effects occur usually 3-6 post-RT, or even years later.2 For CRP, the most common symptom is uncommon bleeding that may cause iron-deficiency anemia severe enough to warrant transfusions.2 Patients may also have signs of a bowel obstruction, including constipation, rectal pain, bowel urgency, and fecal incontinence because of overflow.2
If you have similar symptoms and have had radiation for prostate cancer, although CRP may be suspected, an endoscopy should be done to rule out any other conditions that may cause these symptoms, like inflammatory bowel disease, colitis, or a separate malignancy.
How to reduce the risk of CRP
In order to prevent or best reduce the risk of CRP, keeping the rectum out of the irradiation fields is a priority in RT. Using planning constraints helps reduce the amount of radiation to the rectum and decreases the risk of rectal toxicity.2 Genetic associations with CRP are being researched, and it is thought that in the future, screening to identify high-risk patients may be done and thus, additional preventative measures can be taken for those patients to further reduce their risk of developing CRP.2 Different RT techniques and radiation particles are also being studied to see if they carry less toxicity while still maintaining effectiveness. Medications to help reduce the risk of CRP are not widely used because they have not been shown to have any significant benefit.2
There are rectal devices that can be inserted to help shield the rectum from irradiation. Endorectal balloons are inserted into the rectum for each radiation treatment to further distance the dorsal rectal wall from the prostate and hopefully reduce the likelihood of radiation exposure. Rectum spacers can be implanted as tissue filler into perirectal fat to further separate the rectum from the prostate; this is implanted under ultrasound guidance, and then biodegrades within 6 months of insertion.2 The long-term effectiveness of these devices has yet to be determined.
Treatment for CRP
Treatment for CRP is based on the severity of symptoms and the type of CRP. There are 3 main kinds:2
- Inflammation predominant form (I-CRP)
- Bleeding predominant form (B-CRP)
- Mixed form that has features of both I-CRP and B-CRP
There have been no major randomized trials to determine how effective treatment is for CRP, but there have been smaller trials, which have guided treatment to this point. Treatment typically consists of three main options: medical therapies, endoscopic therapies, and surgical intervention.2
Medication is the main treatment for I-CRP, and can be given in pill, suppository, or enema form.1,2 These medications, which include Carafate, Azulfidine, and Flagyl help to control inflammation and reduce bleeding.1 Stool softeners may also be given to help open up any obstructions that may be in the bowel. Those patients with B-CRP should be monitored for anemia and given iron supplements or transfusion if necessary. Antibiotics may eventually be given, along with endoscopic treatment to control the bleeding.2 Other treatments like topical formalin and laser treatment have been used sparingly because of potential adverse risks and availability, but are not generally recommended.
Overall, the natural course of CRP does tend to improve over time without treatment.2
Some patients will have severe CRP, and surgery is a last-resort treatment. It is often only for those patients who have a stricture, permanent bleeding, perforation, or a fistula that has not responded to other treatments.2 Surgical options include excision, diverting stoma, and reconstruction of a coloanal J reservoir.2 There are significant surgical risks with any of these, and the overall post-operative mortality rate is 3 percent.2
CRP is a common and treatable side effect
CRP can be a common side effect of RT for prostate cancer, even months or years after you’ve finished treatment. Talk with your doctor about the risks of developing CRP, and what is done during treatment to help reduce your risk of developing it. If you do eventually experience CRP, although it does typically resolve over time in many cases, there are treatments available that can help reduce your symptoms and improve quality of life while you heal.
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