Prostate brachytherapy, or seed implantation, is a popular treatment choice in the United States for men with localized prostate cancer. It essentially works by concentrating radiation within the target organ (the prostate in this case) while minimizing radiation to surrounding structures, such as the bladder and rectum.
Advantages of this treatment include its highly effective concentration of radiation and the fact that only one treatment is necessary. Brachytherapy has been a good solution for many patients who cannot take much time away from work or other obligations for surgical recovery or for weeks of trips to the radiation treatment center. The effectiveness (or cure rate) for brachytherapy is similar to the other major treatment options for patients with low-risk prostate cancer.
What is seed implantation?
Seed implantation, otherwise known as “brachytherapy,” refers to the placement of radioactive material into tissues. Prostate brachytherapy refers to utilizing a minimally invasive technique to place radioactive sources (contained within a metallic casing) directly into the prostate. Hollow needles are placed into the prostate in the operating room, and the radioactive seeds are inserted into the prostate through the hollow needles. Ultrasound and computerized treatment planning in the operating room achieve accurate placement of seeds.
The advantage to this approach of delivering radiation is the ability to accurately deliver a high dose of radiation directly into the prostate while minimizing the radiation dose to the nearby tissues and organs. Patients are usually discharged from the hospital within hours of the procedure, and patients return to normal function within several days.
Is seed implantation a new procedure?
Who is a candidate for seed implantation?
How is seed implantation performed?
What happens to the seeds?
Do radiation precautions need to be followed?
The body blocks most of the radioactivity that is produced by the implant. However, some radioactivity may be given off during the time periods listed above. Bodily fluids are never radioactive. The Nuclear Regulatory Commission (NRC) has not recommended radiation precautions for implant patients. Nevertheless, we recommend the following:
- Children should not sit on your lap for more than five minutes a day for two months after an implant.
- Pregnant women should avoid close contact with you for more than a few minutes up to two months after an implant.
What are the side effects/risks?
Ten percent of patients will require a catheter for several days after the implant. Very few patients will need a catheter for an extended period. You may experience blood in the urine, which will resolve on its own. Few, if any patient, develop an infection, as all patients receive antibiotics before the procedure.
The most common side effects are related to urinary symptoms. You will likely experience some degree of urinary frequency and urgency. You may also experience a sensation of burning during urination and the need to get up at night to urinate more frequently. After a palladium implant, urinary symptoms usually last from two weeks to six months, and after an iodine implant, these symptoms can last from two weeks to nine months. There are medications that can help alleviate these symptoms in most cases.
Patients rarely experience rectal irritation or bleeding, and it is rare for an implant to result in damage to the bladder or rectum causing bleeding and/or pain. It is also reported, but unusual, for patients to develop bladder cancer years after radiation to the prostate with seed implant. Impotence has been reported in 15 percent of patients two years after the implant and 40 percent of patients four years after the implant. Patients often experience a "dry ejaculate,” whereby they are able to have a normal-feeling erection and intercourse, but their ejaculation is dry.