Minimally Invasive Treatments for Localized Prostate Cancer:
The Role of Brachytherapy (or Seed Implants)
Last year in our country 232,090 new patients were diagnosed with prostate cancer —the second most common cancer in the United States. Although many people believe that prostate cancer will not likely be fatal, 30,350 prostate cancer specific deaths occurred in the United States in 2005, and 85 percent of these patients also had bone metastases. Although prostate cancer is often thought of as an old man’s disease, over the past 10 years, a shift towards younger man has been observed by many urologists. As a matter of fact, in my own practice, of the most recent 10 patients diagnosed with prostate cancer 90 percent were younger than 60 years old, 50 percent younger than 55 years old. These statistics reflect the perception that prostate cancer is now epidemic.
In order to decrease the number of cancer deaths due to prostate cancer, more screening and quicker diagnosis have identified this cancer at an earlier stage. The result has been an improvement in the likelihood that these patients can be cured with existing monotherapies such as brachytherapy (seed implant), cryotherapy (freezing), external beam radiation, high frequency ultrasound (HIFU) and radical prostatectomies.
The change in risk stratification among prostate cancer patients from 1989 to 2002 has been dramatic. In 1990, while 30 percent of the patients were considered low-risk patients (likely to respond to monotherapy), 40 percent were considered high-risk patients (those needing multiple therapies to have a chance for a cure). In 2002, while 47 percent were low-risk, only 16 percent were higher-risk. It is our hope that, with 50 percent of our patients newly diagnosed with prostate cancer in the low-risk category, there will be an improvement in the long-term outcome with such less-invasive procedures as brachytherapy, cryotherapy and external beam radiation.
Brachytherapy, or seed implant, is the placement of short lived radioactive seeds within the prostate, allowing the prostate to be treated while surrounding tissues remain safe. Each seed has a one-centimeter radius of influence . It is this small radius of influence that makes seeds locally effective but unlikely to harm people around us. Also, by using a sophisticated computerized system intra-operative, the implant of the seeds can be accurate, highly therapeutic and safe. Typically patients go home the same day without the need for a catheter. Pain medications are often refused by patients in the post-operative course.
Among the various monotherapies, brachytherapy has been gaining popularity because it is an outpatient procedure that allows patients to return to their normal lifestyles more quickly. In fact, many patients have returned to work the day after surgery. Other benefits of brachytherapy are the low incidence of both impotence and incontinence. What’s more, with this treatment younger men ranging in ages from 50 to 60 with normal sexual function have less than a one-percent chance of developing impotence and less than a one-percent chance of becoming incontinent.
Accordingly, brachytherapy has become one of the preferred therapies for the treatment of prostate cancer. The Millennium Research Group reported that as of November 2005 more brachytherapy has been done in our country for the treatment of prostate cancer than radical prostatectomies (the old standard). It has been estimated by the same group that in 2006 approximately 82,000 brachytherapy cases will be done in the US.
Formerly, a major criticism of the use of brachytherapy had been lack of long-term data. However, there are now four major groups from various institutions reporting 10- to 16-year data. Typically the survival data is described as freedom from failure. Failure is described as three consecutive increases in PSA. Mount Sinai has reported that, after 10 years, 96 percent of their patients have had no change in PSA. Another major institution in Seattle and a major pioneer in this type of treatment have quoted that, after 16 years, 86 percent of their patients have had no change in PSA and therefore no progression of cancer. This is now being confirmed throughout the country in a number of highly respected institutions.
In comparison to the brachytherapy data, modern surgical series of radical prostatectomies from such major institutions as Johns Hopkins have reported that, after 10 years, 68 percent of their patients have had no change in PSA, Washington University (65 percent), Baylor College of Medicine (73 percent), and Mayo Clinic (52 percent). This demonstrates that brachytherapy is a good alternative to Radical prostatectomies as far as 16-year outcomes are concerned.
The possible complications seen with brachytherapy are: rare inflammation of the rectum (or proctitis) seen in less than five percent of patients and, as mentioned above, low rates for impotence and incontinence. Indeed, because of its low risk of complications and its great effectiveness in the treatment of prostate cancer, brachytherapy is becoming a very important tool in the treatment of this condition.
Such modalities as brachytherapy are becoming the standard of care, primarily since data collected over that past 16 years are now reassuring us of the long-term effectiveness of the treatment when compared with other single modalities. Finding effective treatments for prostate cancer with minimal complications and offering the possibility for people to return to quality daily living are great benefits of this approach to treatment. This is probably the reason why more brachytherapy has been done in our country since November 2005 than radical prostatectomies.
