Radiation Therapy

General consideration

In discussing treatment for prostate cancer, it is important to consider patient factors such as age and general performance status as well as tumor factors such as Gleason score, initial serum PSA, and estimated clinical volumes/stage of the tumor. If a patient has less than a 50 percent chance of surviving 10 years, it is difficult to measure the positive effect of treatment. The side effects of different therapies also have to be considered. It is optimal when patients come to a treatment decision based on consultation and input from both surgical and radiation oncology services.

Radical or complete prostatectomy

This is the treatment choice for patients with organ-confined disease and a life expectancy of more than 10 years. Generally, age 70 is used as a relative cutoff for strongly recommending surgery. Using an anatomical retropubic approach, Walsh has shown that the carvernosal nerves that mediate erectile function can be identified and avoided, reducing postoperative erectile dysfunction considerably. This can be done in greater than 50 percent of men under the age of 60 but is less successful in men as they approach and surpass the age of 70. Significant urinary incontinence may be encountered in up to 4 to 8 percent of patients, and bladder neck contractures can occur in 2 to 6 percent of patients. Surgical mortality is less than 0.2 percent but 1 to 2 percent of patients may develop pulmonary emboli. The radical perineal prostatectomy is associated with reduced blood loss as the dorsal venous complex is not divided. It may be the preferred approach in very obese men or in those with a history of abdominal or pelvic surgery where significant retropubic scarring and fibrosis are suspected.

External beam radiation therapy

This is an option for localized prostate cancer and is the treatment of choice for T3 disease. This modality is discussed in greater depth in Chapter 20. In general, it is administered in divided doses ranging from 70 to 80 Gy and is well tolerated. Approximately 3 to 5 percent of patients will experience persistent rectal or bladder symptomatology and greater than 50 percent of patients develop erectile dysfunction within 2 years. Hematuria or hemorrhagic cystitis is a late development in a small percentage of patients. Techniques of conformal therapy have reduced unwanted radiation to the bladder and rectum.

Interstitial brachytherapy

Ultrasound-guided transperineal brachytherapy has become an accepted modality for the treatment of localized prostate cancer using 1251 or 103 Pd radiation sources. Recommended minimum dosing is 144 Gy. Optimal candidates have a serum PSA of less than 10 ng/mL, and a Gleason score of 6 or lower. Many centers utilize short-term neoadjuvant hormonal blockade given the difficulty in treating prostate glands larger than 50 g. Conversely, glands smaller than 20 g are difficult to implant. Short-term complications include urinary retention, urethritis, and irritative voiding symptoms, especially in patients with a history of lower urinary tract obstructive symptoms. Long-term major complications include stricture or contracture development and proctitis. Incontinence is uncommon but averages 20 percent in men with a history of transurethral resection of the prostate. Short-term results (5 years) suggest similar outcomes to surgery or external beam radiation therapy, but long-term data are lacking. Results are not as encouraging for men with tumors of Gleason grade 7 or higher. Newer protocols include combination of brachytherapy and external beam

Cryosurgery

Ablation of cancer by tissue freezing. Performed percutaneously with liquid nitrogen or argon. New techniques employing a greater number of smaller probes associated with less incontinence and/or erectile dysfunction. Pelvic pain persists.

Watchful waiting

Trial of watchful waiting vs. surgery demonstrated 2 fold increase in prostate cancer deaths and 70% increase in metastasis rate in patients observed for 5 years. Overall death rate similar in each group. Appropriate for elderly patients with significant co-morbidity or patients with minimal burden disease conflicted about treatment options.