NONSURGICAL TREATMENTS FOR PROSTATE CANCER: INTERSTITIAL RADIOTHERAPY OR BRACHYTHERAPY

A century ago, Alexander Graham Bell described how a tiny fragment of radium sealed in a glass tube was inserted into a cancerous tumor to kill the tumor.

This early form of radiation therapy, now called interstitial radiotherapy or brachytherapy, has been developed to a point where urologists are impressed with its effectiveness compared to surgery for the treatment of prostate cancer.

For this treatment, die urologist refers the patient to a radiation oncologist—a cancer specialist who uses doses of radiation called "seeds," which are tiny pieces of radioactive material that are implanted permanently or temporarily by needle. Disc-sized capsules of radioactive palladium 103 or iodine 125 are placed inside die prostate to kill adjacent cancer cells. They are usually inserted through the skin directly into the prostate using the perineal approach (through the perineum).

Brachytherapy is done under anesthesia, and it takes about two hours. At considerably less cost than a total prostatectomy, it can be done on an outpatient basis. Usually, there is minor pain, and soreness or discomfort may last for around ten days.

About forty-five seeds are typically used, which are active for three to six months. They are then cast off and digested by the body. They do not emit any radiation outside the tumor that could cause any damage, but they do irradiate both malignant cells and healthy ones. The theory is that the healthy cells will heal while the cancerous ones should not.

As for side effects, brachytherapy carries less chance of difficulty in controlling urination than does surgery. The impotence rate is estimated at around 25 percent.

Dr. Heyoung McBride and Dr. William Homaday, staff members at Iowa Methodist John Stoddard Center, say the procedure has opened a new option for many of their patients. One advantage they cite is that the accuracy allows the seeds to deliver doses of radiation up to three times that of standard radiation, which at those doses would likely damage surrounding organs.

Another proponent of its use is Dr. John Koval, a radiation oncologist who comments that the radiation from the palladium does not spread very far. In fact, one centimeter (four-tenths of an inch) from the seed, the radiation level drops off dramatically, minimizing the effect on neighboring tissue and organs. Dr. Koval further comments that brachytherapy is preferred for those who have early stages of prostate cancer. For those with more advanced stages of the disease, it may be used in conjunction with other types of treatment.

The use of seed implants was initiated at Seattle's Northwest Hospital in 1986. More than 700 physicians around the world were trained in the procedure. They first used only iodine pellets. Soon afterward, a new seed called TheraSeed palladium 103 was introduced, offering a more aggressive attack on tumor cells than the iodine seed. Although longer-term studies are still desirable, the treatment has several advantages over invasive surgery for local tumors. As a one-time outpatient procedure, it's very cost-effective—half of what a radical prostatectomy would cost.

"I hesitate to endorse radioactive seed implantation for men who are good candidates for surgery, simply because there are no results documenting efficiency beyond five years. More research has to be done," counters the University of Michigan Medical School in Ann Arbor's Dr. Joseph E. Oesterling.

Still, the Pacific Northwest Cancer Foundation in 1995 reported a 91 percent success rate in controlling early-onset prostate cancer with seed implantation therapy. In another study, 188 patients with more aggressive prostate cancer were treated with both external-beam radiation therapy and seed implantation. The six-year results show a 78 percent disease-free success rate from prostatic carcinoma.

Bladder and bowel irritation are substantially reduced with the implants compared to external-beam radiation, even though the implants deliver about twice as much radiation to the prostate, according to Dr. Michael Dattoli, a radiation oncologist at University Community Hospital in Tampa, Florida. He has found that incontinence rarely occurs, and impotence occurs in about 5 to 10 percent of men under the age of seventy, similar to external radiation and much better than surgery.

Implanting palladium 103, which is more expensive than iodine 125, costs between $5,000 and $ 11,000 depending on the size of the prostate, Dr. Dattoli said. Surgery, by comparison, costs between $20,000 and $28,000, excluding the recovery period at home.

However, brachytherapy is not for everyone. A disadvantage is cited for patients who had a TURP, as it can make the process less effective or increase the complication rate. The TURP changes the geography of the prostate gland and may interfere with uniform placement of seeds. In one study of 274 prostate cancer patients with brachytherapy at the Northwest Tumor Institute, a forty-month follow-up found incontinence in fourteen of 274 patients. A closer look shows that ninety of these 274 patients had a prior TURP, including all fourteen of those with incontinence. In the other 184 patients without TURPs, none had developed incontinence.

According to Dr. Kent Wallner, a radiation oncologist at Memorial Sloan-Kettering Cancer Center in New York, brachytherapy is not ideal for patients with larger tumors or those whose cancer has spread beyond the prostate capsule. For these patients, external-beam radiation continues to be the treatment of choice. He said that the procedure appears to be most effective for small, localized tumors at stages Al, A2, B1, and B2.

There are side effects, the most common of which is irritation of the urinary tract—a sudden urgency to urinate, burning or irritation, or blood in the urine. The same symptoms may show up during a bowel movement. Problems of infection of the prostate may also develop.

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Men's Health Erectile Dysfunction