palladium seeds

Pd-103 Seeds For Prostate Cancers

What patients should expect from Palladium-103 brachytherapy (seed implantation for prostate cancer)

In order to treat prostate cancer, radioactive Palladium-103 or Iodine-125 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.

About radioactive seed implantation for prostate cancer

Internal radiation therapy, also called Interstitial Radiotherapy or Brachytherapy involves implanting radioactive seeds into the prostate gland to treat cancer.

In selected men, this option offers quick, minimally invasive treatment with good cancer control. Small radioactive rice-sized pellets or “seeds” (Palladium 103 or Iodine 125) are placed directly into the prostate gland and give off a known amount of radioactivity into the surrounding prostate tissue. In this way, radiation is placed as close as possible to the cancerous cells so that the pelvic organs are exposed to less radiation than with external beam radiation.

Seeds are implanted without a surgical incision. They are inserted through the skin of the perineum (just behind the scrotum and in front of the anus) using small pre-loaded needles. General or spinal anesthesia is used. Each seed is carefully placed in a predetermined location and depth. Placement is guided by a template attached to an ultrasound probe and a computer plan is designed specifically for the size of the patient’s prostate. Placement is monitored in real time with ultrasound and fluoroscopy.

The permanent seeds give off radiation continually for an extended period of time. The amount of time that the seeds remain radioactive depends on the dose and what type of radioactive material is used. For example, the half-life of Palladium-103 is 17 days. That means that the prostate receives half of the dose in the first 17 days; then one quarter in the next 17 days. The useful dose will have been delivered in three to four half-lives.

The entire gland gets treated because microscopic cancer cells may be present at different sites in the prostate even though the biopsy in the general area was negative. The seeds irradiate a small volume of tissue so several seeds have to be placed to cover the entire gland. The number of seeds used can range from 40 to 150, depending on the size of the prostate gland.

Potential side effects

Any medical treatment may cause side effects or put you at risk for a more serious and/or permanent complication.

You may experience a few, none, or (very rarely) all of these side effects. Most will disappear or lessen with time. Also, if other types of treatment are given in conjunction with radiation therapy, side effects may be more frequent and/or more severe than if radiation therapy alone had been given.

Probable side effects

  • Fatigue
  • Pelvic discomfort
  • Urinary frequency (feeling the need to urinate frequently Urinary urgency, or feeling the need to urinate right away)

Possible side effects

  • Burning during urination
  • Urinary retention (passing urine, but unable to fully empty the bladder)
  • Urinary obstruction (unable to pass urine)
  • Rectal bleeding
  • Sexual dysfunction
  • Urinary incontinence (unable to control bladder)
  • Bowel incontinence (unable to control bowels)
  • Diarrhea

Rare side effects

  • Rectal injury requiring surgery

Dietary guidelines

Some foods and liquids (acidic food or amino acid groups) can be slightly irritating to the bladder, causing increased urinary frequency, discomfort, and a slower stream.

Generally, it is not necessary to eliminate these foods from the diet, but you may wish to decrease the amount, particularly if you are having a lot of symptoms.

  • Acidic Foods
  • Alcoholic beverages
  • Cranberries and juice
  • Apples/apple juices
  • Grapes/grape juice
  • Guava
  • Cantaloupes
  • Peaches
  • Carbonated beverages
  • Pineapple
  • Chilies/spicy food
  • Plums
  • Citrus fruits and drinks
  • Tea and Coffee including decaf
  • Tomatoes
  • Strawberries
  • Chocolate
  • Vinegar
  • Vitamin B complex

Radioactive Palladium-103 or Iodine-125 seeds are used to treat prostate cancer by placing them directly into the prostate gland, using either after loading needles with a special "gun" or preloaded needles.