Permanent Interstitial Brachytherapy for the Management of Carcinoma of the Prostate Gland, Gregory S. Merrick, MD, Kent E. Wallner, MD, and Wayne M. Butler, PhD, The Journal of Urology, 2003;May;169:1643-1652.
|Type of Study||Review of published literature.|
|Purpose||To summarize literature about permanent prostate brachytherapy including biochemical outcomes, quality of life parameters and areas of controversy.|
|Number of Patients||Not applicable.|
|Type of Patients||Varies by study.|
|Length of Time Patients Were Followed||Varies by study; up to 10 years.|
|Results and/or Conclusions||
In a review of current published literature, the authors examined numerous brachytherapy issues including outcomes, quality of life and areas of controversy. The review resulted in the following conclusions.
OUTCOMES RELATED TO RISK FACTORS: Brachytherapy can be effective for patients with low-, intermediate- and high-risk features.
“Using various planning and intraoperative techniques, the majority of the brachytherapy literature demonstrates durable biochemical outcomes (cure rates) for patients with low, intermediate and high risk features.”
Cited survival rates (biochemical disease-free survival) included:
|•||87-96% after five to 10 years for low-risk patients (Gleason score of 6 or less, PSA of 10 or less and T1c/T2a staging according to 1997 American Joint Committee on Cancer (AJCC) criteria).|
|•||82% after nine years for intermediate-risk patients (Gleason score of 7 or greater, PSA of 10 or greater, or stage T2b according to 1997 AJCC criteria). For hormone naïve patients treated with brachytherapy and supplemental external beam radiation therapy, a 6-year rate of survival of 97% has been reported.|
|•||76% after five years for high-risk patients (with two or three certain risk factors including Gleason score of 7 or greater, PSA of 10 or more and/or stage T2b or greater according to 1997 AJCC criteria) receiving supplemental external beam radiation therapy, followed by a Pd-103 boost. For hormone naïve patients, an 80% rate has been reported after six years for patients with certain characteristics.|
|•||Not all studies of intermediate- and high-risk cases have shown favorable results.|
“Although not all patients are good candidates for brachytherapy, to our knowledge a reliable set of pretreatment criteria to predict implant-related morbidity is not available. Most alleged contraindications to brachytherapy have been propagated with little or no supporting data.”
|•||AGE: Brachytherapy can be an effective treatment regardless of the patient’s age. “There has been a reluctance to recommend brachytherapy for younger patients… Outstanding biochemical outcomes with a plateau on the PSA control curve have been reported for hormone naïve patients who undergo brachytherapy who are 62 years or younger.”|
|•||PROSTATE SIZE: Brachytherapy can be an effective treatment for patients with large prostate glands, who are often counseled not to receive this type of treatment.|
|•||“Contrary to popular perception, groups have reported that appropriately selected patients with a large prostate can be implanted with acceptable morbidity.”|
Debunking Additional Myths:
In addition to young patient age and large prostate size, alleged contraindications to brachytherapy — generally not supported by clinical findings — include pubic arch interference, chronic prostatitis, transurethral resection of the prostate, obesity, inflammatory bowel disease and adverse pathological features such as high Gleason score, perineural invasion and percent positive biopsies.
QUALITY OF LIFE ISSUES (short-term side effects and long-term complications)
|•||“Although a reliable set of pretreatment criteria to predict implant related morbidity is not available, severe urinary and rectal morbidity is rare.”|
|•||“After brachytherapy almost all patients have some degree of urinary irritative/obstructive symptomatology with acute urinary retention in 2% to 22%.” (NOTE: According to principal author Dr. Merrick, this figure now ranges from 2% to 32% and drops to less than 2% after five days.) Drugs are used to alleviate these symptoms and the timing may substantially influence their effect.|
|•||There is a 5% to 12% risk of urethral strictures up to five years post-treatment, easily managed by dilatation.|
|•||Rectal complications consist primarily of mild proctitis which usually resolves spontaneously.|
|•||Long-term bowel dysfunction is relatively uncommon, although preliminary results of a randomized trial indicate I-125 implants result in greater rectal morbidity.|
|•||Results of studies regarding impotence after brachytherapy vary. In one study, when those who maintain potency are combined with those who take medication to restore erectile dysfunction, 92% of men are able to maintain erectile function six years following brachytherapy. “Erectile dysfunction has been reported in 6% to 90% of patients who undergo brachytherapy,” the journal article noted. However, it also indicated most patients with brachytherapy-induced erectile dysfunction respond favorably to sidenafil (medication). “The reported wide ranges of erectile dysfunction likely reflect the differences in follow-up, patient selection and the mode of data collection. In the only brachytherapy series using a patient administered, validated quality of life instrument, 52% of patients who underwent monotherapy brachytherapy maintained erectile function at 6 years.” The strongest predictor of erectile dysfunction is the patient’s functional level before implantation.|
PHYSICIAN EXPERTISE IS IMPORTANT
“It has become increasingly apparent that the efficacy and morbidity depend on implant quality.”
Principal Investigator: Gregory S. Merrick, M.D., Schiffler Cancer Center, Wheeling, W.V.