Brachytherapy, also called seed implantation, is a type of localized internal radiation therapy that is often used to treat prostate cancer. It can also be used to treat head and neck, eye, cervix, and breast cancer. Prostate cancer is treated with interstitial brachytherapy, meaning the radioactive pellets called “seeds” are placed directly inside the tumor. Brachytherapy can be used as the only radiation therapy or in combination with other radiation therapies, such as external beam radiation therapy (EBRT).
Types of Brachytherapy
There are two types of brachytherapy used to treat prostate cancer:
Permanent (Low Dose Rate, or LDR) Brachytherapy
Low dose rate (LDR) brachytherapy is a form of radiation therapy that uses very small radioactive seeds (usually made of iodine-125 or palladium-103) to treat prostate cancer. The seeds, usually around 100, are placed directly into the tumor through small needles inserted between the scrotum and anus. The seeds give off radiation for weeks or months, destroying and preventing the cancer tumor from growing. When the radiation is used up, they stay in place permanently.
Temporary (High Dose Rate, or HDR) Brachytherapy
HDR brachytherapy is not as frequently prescribed as LDR brachytherapy. It delivers a highly-targeted dose of radiation over a short period of time using radioactive pellets usually made of iridium-192 or cesium-137.
Because the seeds will be removed afterwards, hollow needles first place catheters (soft nylon tubes) into the prostate. The seeds are placed into and then removed from the catheters for 5-15 minute intervals in 1-4 different sessions over a 2-day time period. At that point, the catheters are removed.
Who Can Have Brachytherapy?
Brachytherapy is a good option for patients with early-stage prostate cancer or those who are not good candidates for surgery. Men that might have a risk of cancer spreading (metastasis) sometimes combine brachytherapy with other types of radiation therapy like external beam radiation therapy (EBRT).
Men that might not be good candidates for brachytherapy (or who may experience more side effects than others) include patients that:
- have had a transurethral resection of the prostate (TURP)
- have urinary problems
- have an enlarged prostate
What are the Advantages of Brachytherapy?
The biggest advantage of brachytherapy is that it’s a localized minimally invasive treatment. It does not require a large incision like traditional surgery. The radiation is delivered through needles inserted into the prostate. This can result in less damage to the surrounding healthy tissue than other radiation therapy.
Some additional benefits of brachytherapy include:
- Brachytherapy is a highly-targeted treatment that can precisely deliver radiation to the tumor.
- Brachytherapy is a relatively short treatment.
- Brachytherapy is a relatively painless treatment.
- Brachytherapy has a lower risk of side effects than other radiation therapies.
Possible Risks and Side Effects of Brachytherapy
Like all cancer treatments, brachytherapy has risks and side effects. Most of these problems are temporary and go away after treatment is finished. However, some people may have long-term side effects, such as infertility. If your symptoms are severe or unexpected, be sure to speak with your health care provider.
If you receive LDR brachytherapy treatment, your body will contain radioactive material for a time and give off radiation. You may need to stay away from pregnant women and children and hospital staff may keep their distance. Sometimes radiation may trigger airport security and you may want to bring a doctor’s note. You may also be asked to use a condom during sex.
With HDR brachytherapy, because the seeds do not stay in the body, no precautions are needed.
Common urinary problems after brachytherapy include:
- Trouble Urinating – This is usually temporary, and resolves within a few weeks. If you are unable to urinate completely, a condition called urethral stricture, call your doctor right away.
- Burning Sensation – Because radiation irritates the bladder, you might get a burning feeling while urinating.
- Bloody Urine – Having brown or red urine immediately after the treatment is common.
- Incontinence – Incontinence is the leakage of urine. It usually improves within a few weeks, but may persist for a few months but severe incontinence is uncommon.
- Frequent Urination – Frequent urination usually improves within a few weeks, but may persist for a few months.
Fatigue is one of the most common side effects of brachytherapy. It may begin soon after the treatment starts and may last for a few weeks or months.
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Radiation can damage the lymph nodes near the prostate. If this happens, fluid can be retained in the legs and genital area which causes pain and swelling. Physical therapy can help relieve these symptoms.
Brachytherapy of the prostate can irritate the bowels causing a condition called radiation proctitis. Some common bowel problems include:
- rectal pain
Infertility & Sexual Side Effects
Brachytherapy treatment, because it involves the prostate, creates fertility and sexual side effects. Men who receive brachytherapy may experience a decrease in sperm count and fertility. Additionally, some men may experience a decrease in libido and erectile function over time.
What Does Treatment Involve?
Brachytherapy takes place in a hospital or clinic and can be an outpatient procedure or one that requires an overnight stay.
Your Planning Session
The first step to receiving treatment is a brachytherapy planning session, often 1-2 hours long, for you and your doctor to discuss your treatment options and create a treatment plan specifically for you. Some of the topics that will be covered include:
- The type of brachytherapy treatment that is best for you
- The number of radioactive seeds that will be used
- The location of the seeds in your prostate
- How the radiation will be delivered
- What side effects you may experience
- How often you will need to see your doctor
Your doctor will also give you a copy of your treatment plan to take home with you.
Before the Procedure
Your doctor will give you specific instructions on how to prepare for the brachytherapy treatment. You may be asked to stop taking certain medications and to avoid eating or drinking before the procedure.
Placing the Seeds
You will be asked to wear a hospital gown and to lie on your back on a table.
You will either be given an injection that numbs the lower half of the body (called spinal anesthesia) or general anesthesia where you are asleep during the entire procedure.
Imaging tests like MRIs, ultrasounds, and CT scans are done to guide the needles into the proper area, usually in the area between the scrotum and anus. The radioactive pellets will be inserted through the needles and into your prostate.
After the Procedure
You will be able to go home soon after the procedure or you will need to stay overnight depending on your situation, health, and whether or not you are having LDR or HDR brachytherapy or received general anesthesia.
You will be able to resume your normal activities soon after the procedure. You should avoid strenuous activities for a few days. You may have some discharge and experience some pain and swelling in your prostate and in the area where the needles were inserted. These symptoms should improve over time.
Prognosis for patients who receive brachytherapy treatment for prostate cancer is very good. In one study, 97% of patients who received LDR brachytherapy did not see a return of their prostate cancer within a 17-year time period. In a 2020 study, 98.7% of patients reduced their their PSA levels (a prostate cancer marker) to less or equal to 0.2 ng/mL and were disease free after 10 years.
- Radiation Therapy for Prostate Cancer, American Cancer Society
- Brachytherapy to Treat Cancer, National Cancer Institute
- “Low-dose-rate brachytherapy for prostate cancer: outcomes at >10 years of follow-up”, BJUI International, May 2018
- “The effect of radiation on semen quality and fertility in men treated with brachytherapy for early stage prostate cancer”, Journal of Urology, March 2012
- “A Biochemical Definition of Cure After Brachytherapy for Prostate Cancer“, Radiotherapy Oncology, August 2021