Brachytherapy for prostate cancer, which is also called interstitial radiotherapy for prostate cancer, is a cancer treatment which uses ionizing radiation to destroy cancer cells. The radioactive material is placed either directly into the malignant tumor or very close to it, destroying the deoxyribonucleic acid, or DNA, which holds genetic information, such as cell function, division and growth, within the cancer cells. Since the DNA is no longer intact, the malignant cells are unable to divide and reproduce, and as a result, the cancer cells die. The radioactive material is actually specially-treated rice-sized pellets, often referred to as radioactive seeds. For prostate cancer, these seeds are implanted inside the prostate to kill the malignant cells. Since this type of radiation treatment for prostate cancer does not have the same the problems and lengthy treatment time as with external beam radiation. For prostate cancer patients, this treatment option offers the promise of a quick, minimally invasive treatment option with good control of the cancer.
Techniques for implanting radioactive seeds for prostate cancer have improved considerably over the past 20 years. Technology, such as improved ultrasound equipment and 3D imaging computer systems, now enable better visualization of the prostate and more precise placement of radioactive seeds. For prostate cancer patients, this means doctors are able to deliver a high dose of radiation to the prostrate and still minimize exposure to nearby body organs such as the bladder and rectum.
However, the long-term results of brachytherapy for prostate cancer are still yet unknown. Experts do agree that for the ideal candidate, prostate cancer brachytherapy treatment appears to be equivalent to external beam therapy, extending life up to about 7 to 10 years. But beyond that, it is unclear, which raises some concerns for younger men with a long-term expected survival.
Advantages and Disadvantages of Brachytherapy for Prostate Cancer
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Types of Brachytherapy for Prostate Cancer
There are 2 common types of prostate cancer brachytherapy treatment:
Permanent low dose rate (LDR) – Also called a permanent seed implant, this prostate cancer brachytherapy treatment involves the use of radioactive iodine or palladium in the form of seeds, which are implanted in an area of the prostate that is no larger than a centimeter, and are left there indefinitely. Either iodine or palladium is used for each seed. These two seed types are never combined, because mixing them impairs the precise measuring of the radiation. There is actually no outcome difference between the two radiation seed implants. For prostate cancer patients, iodine tends to cause less intense urinary side effects. However, these treatment symptoms last several months longer than palladium, which has more intense, shorter duration of urinary side effects.
Temporary high dose rate (HDR) – Also called high dose rate, or HDR brachytherapy prostate cancer, this prostate cancer brachytherapy treatment requires the use of a different radioactive isotope, usually iridium-192. Temporary brachytherapy is similar to permanent brachytherapy for prostate cancer in that it involves placing radioactive materials in the prostate. The difference is that the radioactive materials are removed from the prostate after specific period of time.
Seed therapy for prostate cancer can be performed using either a permanent implant or a temporary implant, but never both.
Good Candidates for Brachytherapy for Prostate Cancer
Typically, the best candidate for brachytherapy is a prostate cancer patient who has a small prostate tumor that is still confined within the prostate gland and a very low risk of cancer spreading to other parts of his body. If you are a candidate for external beam radiation for prostate cancer or radical prostatectomy, then you may also be a candidate for prostate cancer brachytherapy treatment.
Since the radioactive seeds are not able to deliver radiation to the lymph nodes which drain the prostate, brachytherapy, for some prostate cancer patients, is not a viable option by itself. If it is suspected that cancer has metastasized in the lymph nodes, your doctor may want to do a laparoscopic lymph-node dissection before beginning seed therapy for prostate cancer.
Are You a Good Candidate for Brachytherapy Alone?
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Even if you are not considered an ideal candidate, prostate cancer brachytherapy treatment is still a viable option. Men with Stage 2b and higher prostate cancer and a Gleason score of 7 or higher, or a PSA level greater than 10 ng/ml may be also undergo external beam radiation therapy as well to boost the effects of the brachytherapy. If they meet certain criteria, men who have had a transurethral resection of the prostate may also be able to undergo seed therapy. For prostate cancer patients with large prostates, doctors may have them in a short course of hormone treatment to reduce the size of the gland before undergoing brachytherapy on their prostate cancer.
What to Expect During Brachytherapy
The procedure for seed therapy for prostate cancer is typically done in an outpatient setting. Patients are usually able to leave 2 hours after having the implant. It is rare for hospitalization, although some physicians prefer that their patients stay overnight to be observed.
Before the brachytherapy, prostate cancer patients will have an ultrasound done, which takes approximately 15 to 30 minutes. Ultra sound images are then created to help doctors determine the prostate’s exact size and shape. Also outlining the area where the biopsy indicated cancer helps in treatment planning. Using a 3D treatment planning computer, doctors are able to determine the exact number of radioactive seeds for the prostate cancer, and precisely where the seeds need to be implanted in the prostate gland, in relation to the other nearby critical structures such as the bladder, urethra, and rectum.
On the day of your prostate cancer brachytherapy treatment, typically, you will be asked to arrive about an hour prior to the start of the procedure. You will be advised to have a clear liquid the day before and to refrain from eating after midnight, to minimize gas and allow the doctor to better visualize the prostate.
Brachytherapy prostate cancer patients generally do not experience pain either during or after the procedure because either they are asleep from general anesthesia or were given an epidural anesthesia so that the area just below the waist is anesthetized. Most men who have general anesthesia are up and walking about a half hour after the procedure, while those who have an epidural are usually up and moving around in about 2 to 3 hours after the procedure. Upon your discharge, you will typically given antibiotics, anti-flammatories such as ibuprophen, and alpha-blockers, which are drugs that allow easier urination. Up to weeks after the procedure, up to two weeks, you may have soreness or a dull ache in the perineal area, but it should not require anything more than regular-strength acetaminophen.
Because of advancements in technology and understanding how to better place the radioactive seeds for prostate cancer, complications and side effects for brachytherapy are much less severe today. Incontinence rates are usually less than 1%, and medications for impotence and other aids have been proven to be very effective for men who do experience erectile dysfunction after brachytherapy for their prostate cancer. Here are some treatment symptoms you may experience from prostate cancer brachytherapy treatment:
Side Effects of Radiotherapy for Prostate Cancer
- Urinary retention
- Bowel problems
- Prostatitis
- Urinary problems/changes, including irritation of the urinary tract
- Erectile dysfunction
- Rectal Problems, including rectal irritation
- Migration of seeds outside of the prostate gland and into the urethra
While the long-term benefits of seed therapy for prostate cancer is still being determined, its short-term results of extending a patient’s life 7 to 10 years is essentially equal to other treatment options, including surgery and external beam radiation. For prostate cancer patients, blood loss during brachytherapy implant is minimal, and the pain is negligible, as opposed to surgery and its inherent risks. Also, the seed implant procedure is completed in a single outpatient visit, in which the patient typically walks out after the procedure in 2 hours or less, while the complete procedure for eternal beam radiation takes about 7 weeks. If you are considering brachytherapy as a prostate cancer treatment options, consult with your team of doctors to become more informed of its potential benefits, risks and side effects to make sure that brachytherapy is the right prostate cancer treatment for you.
