Stereotactic Body Radiation Therapy (SBRT): Side Effects & Risks

Stereotactic body radiation therapy (SBRT) is a type of advanced radiation therapy that is used to treat certain types of cancers, including prostate cancer. 

In SBRT radiation therapy, radiation is delivered in a very concentrated form over a short duration of time (often days and not weeks).

SBRT is believed to work by targeting the DNA of tumor cells, potentially inhibiting their growth and causing tumor shrinkage.

It is used to treat localized prostate cancer when the tumor has not metastasized or spread to nearby organs.

Stereotactic radiation therapy is a type of outpatient treatment. The treatment is usually completed in five sessions over one or two weeks.

Keep reading to learn more about stereotactic body radiation therapy, including the possible side effects of SBRT and how to prepare for the procedure.

What are the Side Effects of Stereotactic Body Radiation Therapy?

Some of the common side effects of stereotactic body radiation therapy are:

1) Urinary Changes

One of the side effects of giving SBRT to the pelvic area is that it can irritate the healthy tissues of the urinary tract and bladder. 

Due to this, you can experience symptoms of:

• Urinary frequency, especially during the night
• Urinary urgency
• Difficulty urinating
• Pain during urination  

2) Bowel Changes

You may develop mild bowel changes. Some of the most common bowel changes due to SBRT include:

• Soft stool
• Increased gas
• Increased bloating
• Increased urgency

Rare side effects of SBRT include frequent or loose stools and aggravation of hemorrhoids.

3) Fatigue

You may develop extreme tiredness for the initial few days after getting SBRT. The feeling of fatigue and tiredness improves after the SBRT radiation therapy is over.

4) Skin Changes

The skin at the treatment area may become:

• Dry
• Irritated
• Itchy

Your doctor can give you a moisturizer or cream to apply to the affected area.

Possible Complications of SBRT

Some of the possible complications of SBRT are:

• Urethritis (inflammation of the urethra)
• Urinary incontinence
• Urinary obstruction
• Weakened bones, which can break easily
• Swelling of legs and arms (lymphedema)
• A new cancerous lesion

How to Prepare for Stereotactic Body Radiation Therapy

Food and Medicines

You will be asked not to drink or eat anything two to three hours before your treatment.

You should talk to your doctor about whether to take your regular medications the morning or night before the procedure. 

Clothing and Other Personal Items

You should wear loose and comfortable clothing.

You should not wear the following during the treatment:

• Contact lenses
• Eyeglasses
• Wigs
• Dentures

Medical Devices

You should tell your doctor if any medical device is present in your body. These may include an artificial heart valve, a pacemaker, stents, neurostimulators, or aneurysm clips.

How to Prepare the Urinary Bladder

• You should empty your bladder an hour before SBRT treatment.
• Then, drink two cups (16 ounces) of clear liquid (water). Finish drinking the fluid half an hour before the treatment.
• Hold your urine until after the SBRT treatment. If you have any trouble holding the urine, talk to your doctor.

How to Prepare the Bowels

• Ideally, you should pass stool within four hours before SBRT radiation treatment.
• If your bowel movements are regular, you don’t require anything to do differently.
• If your bowel movements are not regular, you should not make any changes in your diet or take any laxatives unless recommended by your doctor.
• Your doctor may recommend using an enema in case you have stool in your rectum.

What to Expect During SBRT for Prostate Cancer

SBRT is an outpatient radiation therapy procedure. 

Each SBRT session can take up to one hour. During the SBRT session, the treatment machine focuses radiation beams on the target tissue. 

The target tissue gets a very high dosage of radiation that causes the tumor to shrink. With time, the blood vessels of the tumor close, shutting down its blood supply.

Before the SBRT Procedure

The steps that the healthcare team undertakes before the SBRT procedure are:

Positioning

This involves finding the best position in which to give the treatment. During treatment, you have to remain still, and the doctor may use devices to keep you still and comfortable at the same time.

Marking

This involves marking the target area for treatment. Often, doctors will use tattoos on your skin to mark the area for repeated SBRT treatments.

Imaging

After you are positioned, the doctor will perform imaging scans to get information regarding the tumor, including its size, shape, and location.

During the SBRT Procedure

The procedure is not painful and does not require any anesthesia or painkillers. If you feel nervous or anxious during treatment, your doctor may give you medicine to relax.

After the SBRT Procedure

• After the SBRT procedure, you can drink and eat.
• You can go back to your home the same day after the procedure.
• You can get back to your regular activities usually within one or two days after the SBRT procedure.

Tips for Recovering from SBRT

Tips to Manage Urinary Side Effects

• Limit your fluid intake after six p.m.
• Stay hydrated by drinking plenty of fluids so that your urine remains light yellow to clear.
• Avoid drinks and foods that may irritate your urinary bladder, including alcohol, caffeine, citrus, and spicy foods.
• If you have a decreased or weak urinary stream or difficulty urinating, your healthcare provider may recommend medication to manage the symptoms.

Tips to Manage Bowel Changes

• Eat slowly and chew your food well
• Don’t skip meals
• Don’t drink fluids using a straw
• Do regular gentle physical activity; for example, walking
• Stay hydrated by drinking lots of fluids
• If you develop greater than three or four stools per day or watery stools, inform your doctor.

Tips to Manage Fatigue

• Engage in regular gentle exercise; for example, walking
• Maintain a healthy weight by consuming a well-balanced and nutritious diet
• Take rest or naps throughout the day

Stereotactic Body Radiation Therapy and Fertility

You can be sexually active while getting SBRT radiation therapy unless instructed otherwise by your doctor. 

But, if your partner or you can have children, you should use birth control methods (condoms, etc.) to prevent the occurrence of pregnancy during SBRT treatment. 

If pregnancy occurs during treatment, let your doctor know immediately.

Supplements and Nutrition During SBRT Treatment

It is very important to maintain adequate nutrition during SBRT treatment. Eat a well-balanced and nutritious diet to maintain your energy and strength. Do not try to lose weight while getting treatment.

It’s advised not to consume more than the recommended dietary allowance (RDA) for antioxidant supplements during SBRT treatment, as excessive intake may impact its effectiveness.

The RDA of the antioxidants is mentioned on the supplement bottle’s label. You can also talk to your doctor about this. It is good to eat antioxidant-rich foods.

Conclusion

• Stereotactic body radiation therapy is a kind of radiation therapy that uses LINAC (linear accelerator) to deliver a high dose of radiation to the target area. 
• The radiation beam is focused on small tumors that are present in close association with sensitive areas. It minimizes the risk of radiation to normal tissue.
• It can be used in place of surgery to treat small, isolated tumors in the prostate.

Explore More

What’s The Difference Between Stereotactic Radiation vs Radiosurgery?