Brachytherapy & IMRT

Brachytherapy is a minimally invasive form of radiation therapy used to treat prostate cancer.

In a brachytherapy treatment, approximately 70-120 tiny radioactive palladium (Pd-103) "seeds" are placed into the prostate gland under ultrasound guidance. The seeds are about the thickness of a fine pencil's lead and just over 1/8 inch long. Seeds irradiate the cancer from directly within the gland. These tiny sources of radiation are strategically placed inside the gland, allowing for a high dose of radiation directly to the cancer, where you need it the most, with less to the surrounding tissues you'd like to spare. The implanted seeds are small enough that they will not be felt by the patient. Brachytherapy is also called interstitial radiation therapy or seed implant therapy.

Seed implantation is an effective treatment for men with localized prostate cancer. Seed implantation requires no surgical incision and offers men a short recovery time. Brachytherapy is an outpatient procedure. Patients go home the same day as their treatment. Recovery usually takes only a day or two. Additionally, most men return to their normal activities a few days after treatment. Physicians recommend waiting about two weeks before resuming sexual activity.

Patient Evaluation

A number of factors are considered when evaluating patients for brachytherapy:

• The size of the prostate gland
• The amount of tumor in the prostate gland (the stage);
• And measurements of aggressiveness (PSA level and the Gleason score).

All of these elements help to determine evidence of spread beyond the prostate capsule. These factors are very important in helping determine the number of seeds required and whether a short course of external beam radiation is necessary in addition to the seed implant.

The Brachytherapy Procedure

Prostate brachytherapy, like any surgical procedure, requires a careful evaluation of the patient's complete medical history, medications, and allergies. An examination, appropriate blood tests, Chest X-ray and an EKG are completed in advance. Patients are given a laxative to cleanse the bowel the day before the procedure.

The seed placement procedure is performed in a specially-equipped operating room in tandem by the radiation therapist and the urologist. Working closely together, the team uses ultrasound to guide long thin needles through the skin of the perineum (the area between the scrotum and anus) into the gland.

The seeds are then passed through these needles into the prostate - strategically deployed in the gland as the needles are slowly removed. The seeds remain in the prostate, where they are give off radiation for weeks to months to destroy the prostate cancer cells.

For seed placement, the patient is asleep under general anesthesia (occasionally spinal anesthesia is used in patients unable to tolerate a general anesthetic).

On average, the seed placement takes ninety minutes. The urologist will sometimes place a catheter in the bladder to ensure normal urine flow in the event of temporary swelling of the prostate.

Although the internal seeds emit a low energy radiation with trace amounts of radiation leaving the patient's body, all facilities performing brachytherapy recommend patients avoid close contact with children and pregnant women for a short time following seed placement. As the radiation decreases over time, the seeds become inactive and no longer give off radiation. They can be safely left in place indefinitely.

Combined Treatments and Therapies

Brachytherapy and Hormone Therapy

In cases where the prostate is too large for immediate seed placement, brachytherapy is still possible after hormone therapy to shrink the gland. This is normally accomplished by using medications that block production and action of the male hormone testosterone.

• Injectable medications (Lupron or Zoladex) are most typically used with an occasional oral drug added (Casodex or Eulexin).
• After three to six months of therapy, the prostate size is remeasured by ultrasound.
• While on hormone therapy the tumor typically shrinks in size with the rest of the gland.
• Brachytherapy and External Radiation.

Even patients where there is concern that the tumor has extended beyond the capsule surrounding the prostate may still be eligible for brachytherapy. In these cases, brachytherapy is frequently followed by a shortened course of external radiation to treat areas not adequately treated by the seeds. This combined approach allows for many of the benefits of brachytherapy and is associated with fewer side effects than external beam therapy alone. This is because the amount and duration of external therapy is reduced compared to external therapy alone.

For patients who require combined brachytherapy and external beam radiation, there is normally a delay of about six to eight weeks after the seed implants before external radiation is begun.

Risks Of Bbachytherapy

The chances of developing impotence or incontinence with the brachytherapy procedure are less when compared to other treatments. Impotence has been reported by various groups of patients, although most patients receiving brachytherapy have often reported similar levels of potency before their treatment. The risk of impotence does increase with age; impotence after brachytherapy can often be treated with prescription drugs such as Viagra, Cialis, or Levitra.

Side Effects Of Brachytherapy

Brachytherapy may have some minimal side effects, such as a burning sensation during urination or ejaculation and increase in urinary frequency. These symptoms are usually treated supportively and go away rather quickly. In few patients, temporary difficulties with urination may be experienced for a few weeks to a few months after the implant.