Pd-103 Seeds For Prostate Cancers
What Patients Should Expect from Iodine-125 Brachytherapy (Seed Implantation for Prostate Cancer)
In order to treat prostate cancer, radioactive Iodine-125 or Palladium-103 seeds are placed directly into the prostate gland, using either after loading needles with a special "gun" or preloaded needles. Both of these seeds give off low-energy x-rays, and the majority of the radioactivity is released within a short period of time. Only each seed irradiates a small volume of prostate tissue, and therefore many seeds have to be placed throughout the prostate to cover the entire gland and the cancer site. Because of the low x-ray radiation energy released, radiation exposure to adjacent normal organs is reduced.
The radioactive seeds treat the entire prostate gland because the microscopic cancer cells may be present at different sites within the gland, even though the biopsy in the general area was negative. The number of seeds implanted into the prostate for treatment depends on the size and shape of the prostate gland. On average, the number, of seeds implanted is approximately 100.
In performing brachytherapy, the doctor places a biplaner ultrasound probe in the rectum to image the prostate. The biplaner ultrasound, along with fluoroscopy, gives a multidimensional view of the prostate on several TV screens. These images are then used to accurately place the needles and to space the seeds in the prostate gland. No surgical incision is required.
Needles are advanced through an area of skin (behind the scrotum and in front of the rectum) into the prostate with the aid of:
(1) a template attached to the ultrasound probe and,
(2) a computer plan designed specifically for the size of the patient's prostate.
Radioactive seeds are then deposited through the needle into the prostate gland. The seeds are permanently placed in the prostate gland. Depending on the radioactive seeds that are selected, they give off radiation for 3 months to a year. Both the probe and needles are removed when the procedure is completed. Cystoscope is done to evaluate the urethra and the bladder and to retrieve any seeds found in the bladder.
