Radiation Therapy:

Radiation therapy may be used as an initial treatment for localized prostate cancer. It may also be used as treatment for cancer that has not been fully removed or has recurred after surgery. In advanced cancer, radiation therapy is used to shrink the size of the tumor and relieve symptoms.

Radiation therapy used to be reserved for older men (over age 70) with locally advanced prostate cancer who had a life expectancy of 15 years or less. However, it is now being used more frequently in younger and healthier men.

The two main radiation treatments for prostate cancer are:

• External beam radiation
• Brachytherapy (internal radiation)

Both treatments have generally equal success rates. In some cases, both techniques may be used in high-risk patients.

External Beam Radiation

In external beam radiation therapy, a doctor focuses a beam of radiation directly on the tumor for 35 3-minute treatments given 5 times a week over 7 weeks. 3-D conformal techniques use computers and a three-dimensional image of the prostate to target the tumor precisely, using high-dose radiation beams. It poses a lower risk for inflammation.

Patients considering external beam radiation should be aware that higher radiation doses may reduce the risk for cancer recurrence and improve survival outcome.

Brachytherapy

Brachytherapy is a technique that implants radioactive "seeds" directly into the prostate. Implants can be temporary or permanent. Temporary implants are usually accompanied by external beam radiation. This procedure requires more skill than external beam radiation therapy. Even with experienced doctors, the distribution of radioactive seeds may be uneven, increasing the risk for insufficient doses. In addition, in some cases the seeds can migrate through the bloodstream to other parts of the body.

It is common for PSA levels to temporarily rise, or "bounce," following seed implantation. This effect is not necessarily a sign of cancer recurrence.

Brachytherapy is mainly used for men who have early stage prostate cancer that is relatively slow growing. It is also used in combination with external beam radiation to treat intermediate-risk localized prostate cancer. Poorer candidates for brachytherapy include men who have had transurethral resection of the prostate (TURP) and patients with advanced cancer, high-grade tumors, or very enlarged prostate glands.

Complications from Radiation

Fatigue is a common side effect for several months following radiation therapy. Other complications include:

Gastrointestinal and Bowel Complications. Complications in the gastrointestinal tract are common. Short-term effects include nausea and loss of appetite. Diarrhea is a very common side effect and can last for the duration of therapy. It is usually treated with Lomotil. It usually goes away eventually, but a few patients have diarrhea flare-ups for years afterwards.

Urinary Problems. Many patients experience a need for frequent urination shortly after radiation therapy, and urgency persists longterm for about some patients.

Erectile Dysfunction. Unlike surgery, erectile dysfunction does not usually occur immediately following radiation therapy. However, the risk for this complication increases after a year or more. External beam radiation may be better at preserving sexual function than brachytherapy. Drug therapies for erectile dysfunction may help. [For more information, see In-Depth Report #15: Erectile dysfunction.]

Adjuvant and Salvage Radiation

Radiation may help select patients who still show detectable levels of PSA after surgery (generally 2 ng/mL or less). It may even be useful years after surgery if PSA levels rise.

Depending on timing, radiation after treatment failure is referred to as either:

• Adjuvant radiation is radiation therapy performed within 6 months after radical prostatectomy. One area of controversy is whether to use adjuvant radiation after surgery on patients whose PSA levels are very low or undetectable but who have other test results that indicate the cancer is likely to spread. Patients with adverse findings and low PSA have to weigh the potential complications of radiation therapy against the odds of recurrence without it.
• Salvage radiation is radiation therapy more than 6 months after surgery. Some studies suggest that salvage radiation could be more beneficial than previously thought, even for men with aggressive prostate cancer.

Cryosurgery (Cryoablation)

Cryosurgery is an alternative to standard prostatectomy for men with localized prostate cancer who do not want or who are not appropriate candidates for radical prostatectomy. It is also an alternative to radiation therapy. The goal of cryosurgery is destruction of the entire prostate gland and possibly surrounding tissue. Steel probes are inserted through the skin between the anus and the rectum and into the prostate. Liquid nitrogen is pumped through the probes to freeze all prostate cells, both healthy and cancerous. For success, cryosurgery requires a uniformly frozen area. The dead cells are absorbed and eliminated by the body.

Cryosurgery is typically a 2-hour outpatient procedure, although some patients may need to stay in the hospital overnight. Cryosurgery may also be used as a salvage procedure for patients who have undergone radiation therapy and have had cancer recurrence detected early.

Nearly all patients experience erectile dysfunction after cryosurgery, and urinary incontinence is also common. Other complications of cryosurgery include urinary retention, swelling, and fistula formation. Incontinence and fistulas tend to occur more when cryosurgery is used as a salvage procedure than when it is used as a primary procedure.

This therapy is still considered experimental by some doctors, and there are no long-term data to compare its effectiveness with standard prostatectomy. For this reason, cryosurgery is generally not considered as a first-line initial treatment.