Brachytherapy for Prostate Cancer
What is brachytherapy?
Brachytherapy is radiation therapy that is given inside the body. Radioactive material is put either into or near the tumor. The material may be left in your body or taken out. The tissues closest to the radioactive material receive the most radiation. The tissues further away receive less radiation. This often results in less damage to healthy tissues than when external beam radiation is used. Brachytherapy delivers a higher dose of radiation in a shorter period of time than external beam radiation. Brachytherapy is used to treat some cases of prostate cancer.
What are the different types of brachytherapy for prostate cancer?
Brachytherapy is most often used for prostate cancer that has not moved outside of the prostate gland or the area around it. It may be used with traditional (external beam) radiation when the cancer is more advanced to deliver even higher doses of radiation to the prostate.
Prostate cancer can be treated with low dose rate (LDR) brachytherapy or high dose rate (HDR) brachytherapy.
Low Dose Rate (LDR) Brachytherapy Procedure
LDR brachytherapy may also be called seed therapy, seed implantation, or permanent brachytherapy. It is done in the operating room, and you are usually given general anesthesia to put you to sleep. While you are asleep, a temporary urinary catheter is placed to empty your bladder. Thin needles are placed through the perineum skin (the area between the anus and the scrotum) into the prostate, using ultrasound imaging and a template (small grid) to guide them. The radioactive seeds are inserted through the needles and into the prostate. The needles are taken out, leaving the seeds behind, spaced throughout the prostate. The seeds are not taken out and stay in the prostate. The number of seeds depends on the size of the prostate glands but is often around many dozens. The seeds slowly release radiation into the surrounding tissue, over several months, killing the cancer cells.
LDR brachytherapy is done as an outpatient procedure, and you will go home after a short time in the recovery room. Because of the seeds, your provider may tell you to:
- Limit close contact with children and pregnant women.
- Avoid having children sit on your lap for long periods.
- Avoid sexual intercourse for some time.
- Use a condom during sexual intercourse in case a seed is passed in your semen.
There is also a small risk of the seeds getting out of the prostate and moving to somewhere else in the body such as the chest, abdomen, or pelvis. This is extremely rare, and your provider would let you know if the seed needed to be retrieved if it were to move outside the prostate.
High Dose Rate (HDR) Brachytherapy Procedure
High dose rate brachytherapy may be called HDR, remote afterloading brachytherapy, or temporary brachytherapy. This procedure is done in the operating room most often with general anesthesia to put you to sleep. Hollow needles are placed through the perineum skin (the area between the anus and the scrotum), and into the prostate. In some cases, a template (small grid) can be used to help guide the needles. An ultrasound probe is placed in the rectum to make sure the needles are placed correctly.
While you are asleep, a temporary urinary catheter is placed to empty your bladder. Also, while you are asleep, the needles are adjusted and ultrasound images are taken. These images are used to plan your treatment, called ultrasound-based HDR prostate brachytherapy. Your treatment plan will be made to treat the prostate gland and cancer. A CT scan or MRI scan may also be done to help make your treatment plan.
Some clinics may wake you up once the catheter and needles are in place while other clinics may keep you under general anesthesia throughout the entire treatment.
Once the treatment plan is ready to be delivered, the brachytherapy machine is connected to the catheters. The machine automatically pushes the radioactive source into each of the catheters one by one removing it according to the treatment plan. The amount of time the source stays in a position is called the ‘dwell time’. The dwell time is programmed to ensure the planned dose is given to the prostate. It is also designed to ensure other body parts, like the urethra, rectum, and bladder, receive as little radiation as possible.
To prevent exposure to others, no one is allowed in the treatment room while the source is out of the machine and inside the patient. After the treatment, the radioactive source is removed from your body, and you are not radioactive. The needles and urinary catheter are also removed. Depending on your type of prostate cancer, you may have this procedure repeated once more after a 1–2-week break.
Side effects can include pain or swelling in the perineum and burning and hesitancy with urination due to the urinary catheter, which can last up to 2 weeks. Long-term side effects (months to years after treatment) may include:
- Burning with urination.
- Urinary incontinence (not being able to hold your urine).
- Urgent bowel movements.
- Rectal bleeding.
- Erectile dysfunction (not being able to get or maintain an erection).
Choosing Your Treatment
Not all prostate cancers can be treated with brachytherapy. You should talk to your provider about what treatment is best for you. It is important to talk about possible side effects from each treatment, as these can depend on your age and overall health condition. Each treatment has different recovery times as well. These may help you decide which treatment is best for you.
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