Say That Again, Please: They're Going to Put Radiation Where?
It sounds like details from science fiction: cylindrical radioactive pellets smaller than a grain of rice implanted in the groin to eradicate a potentially fatal disease. But the procedure—known as brachytherapy—is less novel than you might think.
Brachytherapy, a type of radiation treatment, has been around for decades and is a safe and effective intervention for early- to intermediate-stage prostate cancer. However, some clinicians are not knowledgeable about brachytherapy, and some medical centers don't even offer it, instead sticking with external beam radiation or surgery for prostate cancer patients.
This means many men may miss out on a highly effective—and sometimes more convenient—form of cancer treatment, which is less scary than it sounds.
What is brachytherapy?
A type of internal radiation delivery targeted at the cancer itself, brachytherapy is used to treat prostate cancer, as well as cancers of the head, neck, cervix, breast and eye.
People often refer to brachytherapy as radiation seeds because these radioactive pellets are implanted in the area where the cancer is located, such as tumors or other malignant growth.
"The benefit of a technique such as brachytherapy is that it's able to deliver very intense and high doses of radiation at a very short distance," said Leester Wu, M.D., director of radiation oncology at Mount Sinai South Nassau in Oceanside, New York. "In fact, that's kind of what its name implies: Brachytherapy is Greek for 'short.' So, basically, that's the idea: to deliver a high dose of radiation from within to the tumor or a site that you're treating."
Brachytherapy can be done as a standalone treatment or in addition to other cancer treatments, such as external beam radiation.
Two types of brachytherapy can be used for prostate cancer, though the purpose of the treatment is always the same: to deliver concentrated doses of radiation to the cancer.
Permanent low dose rate (LDR) brachytherapy
During low dose rate brachytherapy, tiny radiation pellets are inserted into the site of the cancer. These pellets give off high doses of radiation for a few weeks. The radiation isn't permanent, but the seeds stay there for the rest of the man's life and are harmless.
Patients need to take certain precautions in the couple of months following the procedure, including keeping a distance from children and pregnant women to avoid exposing them to radiation. Plus, they should be prepared to show a doctor's note when checking in at the airport, because even low levels of radiation can be detected in security systems.
Temporary high dose rate (HDR) brachytherapy
During high dose rate brachytherapy, which is less commonly conducted, catheters are used to temporarily place radiation seeds inside the groin. The seeds are removed after each treatment, and the catheters are taken out after the final treatment when the series is completed. Prostate cancer patients who receive HDR brachytherapy can have as many as four treatment sessions.
Who's a good candidate for brachytherapy?
Brachytherapy is recommended for patients with localized prostate cancer, typically defined as low-risk and favorable intermediate-risk cases, said Michael Zelefsky, M.D., chief of brachytherapy at the Memorial Sloan Kettering Cancer Center in New York City and a professor of radiation oncology. These are patients who have stage 1 or stage 2 prostate cancer, determined through a prostate biopsy and the Gleason score.
"In general, brachytherapy, which is the placement of radioactive sources into the prostate, has been shown to be a very effective treatment for early stages of prostate cancer," Zelefsky said. "Patients are good candidates for this procedure if they have normal-size prostate glands, who don't have any significant urinary problems, and their disease is otherwise contained in the prostate gland without any evidence of spread."
Brachytherapy is not the right option for men with an enlarged prostate because clinicians may not be able to place the radiation seeds everywhere necessary to effectively treat the cancer. Sometimes, a patient might have hormone therapy to shrink the prostate before undergoing brachytherapy.
Experts agree brachytherapy is as effective as external radiation, so the choice to have brachytherapy often comes down to its availability and the patient's preference.
If you have young children or a partner who is pregnant, or if you spend a lot of time with grandchildren, then LDR brachytherapy may not be the right treatment choice because of the potential for radiation exposure. The decision may also involve lifestyle needs and scheduling.
"Some men don't want to come back and forth for the daily treatment that external radiation requires," said Robert Lee, M.D., a professor of radiation oncology at Duke University in Durham, North Carolina. "And so, to them, brachytherapy is perceived as being more convenient. There are other men who don't want to go to the operating room and don't want to deal with radiation safety precautions that you need."
How is the procedure performed?
LDR brachytherapy is performed in an operating room in an outpatient setting under general anesthesia in the presence of a radiation oncologist, a physicist and a urologist. The doctor uses a sonogram to guide the needles that contain the radiation seeds, which are typically composed of either iodine-125 or palladium-103 isotopes, to where the seeds need to be implanted. Usually, the needles are inserted through the perineum (the area between the anus and the base of the scrotum), and once they are accurately placed, the seeds are released.
Zelefsky said palladium-103 is often preferred due to its shorter half-life: It stays in the body for less than three months and not many safety precautions are needed because the exposure to others is very limited.
"There's now very advanced planning systems that will kind of map out where the seeds should be, and then under that ultrasound guidance, we will deliver them as per the plan," Wu said.
Between 60 and 90 seeds are placed, depending on the size of the patient's prostate gland. The seeds are left inside the prostate, and the needles are removed. The entire procedure generally takes about an hour.
A patient can return home after it's clear there are no serious urinary problems or other complications. A small amount of blood in the urine isn't unusual, but it's not a major issue. It's rare for a patient to experience any pain or require pain medication, because the procedure is conducted under general anesthesia.
With the less common HDR brachytherapy, catheters are placed into the prostate to prepare for one to four short treatments. A machine, which contains radiation seeds on a wire that goes into the catheters, is used to deliver radiation, typically from iridium-192 or cesium-137 isotopes. Each treatment takes about 10 minutes. The seeds are removed when each treatment is finished, and the catheters are left in until after the final treatment is completed.
What are the risks and side effects?
Brachytherapy is relatively safe but, as with any procedure, it carries potential side effects.
"Because the radiation is being delivered from inside out, collateral radiation that expands beyond the edge of the prostate gland is less than other techniques which involve X-ray beams that are aimed from outside in. And so the toxicity potentially to the bladder into the rectum is lower," Wu said.
Patients may experience temporary urinary side effects, including urgency, burning sensation, discomfort and, less commonly, bleeding. However, Wu stressed that these problems tend to subside not long after the treatment.
Temporary bowel issues, including rectal pain and burning, may occur but are generally short-lived.
After HDR brachytherapy, once the catheters are removed, a patient may experience swelling or pain, which should resolve quickly.
In general, brachytherapy is associated with less sexual dysfunction than with other prostate cancer treatment options, Zelefsky said. However, research suggests roughly 25 percent of patients experience erectile dysfunction after brachytherapy.
How to decide if brachytherapy is the best option
Brachytherapy may not be offered by the medical center where a patient is receiving treatment, so it's important to do your own homework to find a practitioner who provides this type of treatment. The American Brachytherapy Society maintains a list of clinicians by state.
Wu recommends finding a doctor who has the time and patience to clearly lay out the pros and cons of all treatments available. This could mean visiting more than one oncology practice.
"Discussions can be quite lengthy because of all the different variables that are out there," Wu said. "Sometimes it can be very paralyzing when patients have all these options that are discussed and they don't know which way to move because, you know, obviously, they don't want to make the wrong choice."
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