Radioactive Seed Implant
Prostate Brachytherapy Questions And Answers:
My doctor said that prostate brachytherapy had been tried in the past and failed. Why is it a better option now?
Any cancer treatment negatively impacts a patient’s quality of life for a period of time. Different treatments do have different “personalities” and recovery periods though. In general, prostate brachytherapy and radical prostatectomy both tend to create more intensive urinary tract side effects and have a longer recovery period, while external beam radiotherapy tends to create both urinary tract and lower bowel side effects, but often less in magnitude and with a faster recovery period. A comparison of all three methods of treatment, using the FACT-P validated quality of life instrument measurement, is illustrated in (FIGURE 20) (7). There is no perfect quality of life instrument but this one does give a reasonable idea as to the typical magnitude and duration of negative quality of life effects following various treatments for prostate cancer.
The first “breakthrough” technology that lead to the resurgence of the brachytherapy procedure was the development of transrectal ultrasound based imaging guidance in the 1980s, allowing the visualization of the needles and seeds within the prostate, such that the seeds could be reliably advanced to a “target” location within the prostate, with an accuracy of 1-2 mm. The second major development was the emergence of dedicated, powerful computers and software programs to allow the precision sculpting of a radiation dose volume within and around the prostate. These computing programs and imaging guidance continue to advance at a rapid rate.
Will I be able to work after a brachytherapy procedure?
Usually, the answer to this question will be yes, though there will be some issues you need to be aware of. The typical patient is able to return to work within a few days after the procedure, and some have even resumed their work duties the very next day. The main issue created by the brachytherapy procedure is one of urinary urgency and frequency, which may be long lasting for some patients. Even so, as long as there are adequate and rapidly accessible rest room facilities, one may usually work through these symptoms. Too, your doctor and nursing team will try very hard to optimize your medicines to minimize the symptoms after the procedure. Rarely, urinary symptoms following the brachytherapy procedure have been severe enough to warrant work disability, but this has not been the usual case. In general, we have found brachytherapy to be one of the more “work friendly” treatment options, because the recovery is usually faster than that after prostatectomy, and the number of office visits is fewer than with external beam radiotherapy.
My doctor said I am not as good candidate for surgery because I am severely overweight. Am I a brachytherapy candidate?
Yes, if you are otherwise a good brachytherapy candidate, obesity does not interfere with the procedure. Our larger patients have had no more difficulty tolerating this procedure than any of our other patients. Brachytherapy may even be the preferred method for treating large or obese patients, because the larger the patient, the more difficult and less accurate becomes external beam radiotherapy targeting, and the more dangerous may become the radical prostatectomy operation. With brachytherapy, we have the confidence that the intended radiation is being delivered to the prostate target, because we deposit the radioactive sources directly into the prostate volume while we watch it on a television screen, regardless of the size of the patient.
Is brachytherapy better than surgery or external beam radiation therapy?
There is no single treatment demonstrated superior to other treatments. They all appear to work well in properly selected patients. Which treatment, if any, is better than the others, remains a matter of speculation. There may be factors about an individual’s case that cause his doctor to recommend one method over the others. In other cases, the patient may be well treated by more than one of these methods, in which case he will need to make his own decision after discussing the options with his doctors, researching, weighing the potential benefit versus side effects and risks of each procedure. The 80% to 87% ten-year PSA-defined disease-free survival rates in intermediate and favorable-risk prostate cancer patients respectively with brachytherapy are encouraging, and compete well with other treatment approaches (1)(2).
Do you ever combine external radiation with brachytherapy?
In the past, like many practitioners, we tended to routinely combine external beam radiotherapy with permanent seed brachytherapy for patients with locally advanced tumors (>=T2b), those with a PSA level >= 10ng/dl and/or those with a pathology Gleason score of >=7. The rationale was that these patients had a higher risk of disease beyond the prostate that would be potentially better treated by the addition of external beam radiotherapy, due to its ability to cover a larger volume. Though many practitioners still do this, in the year 2000 we essentially abandoned this combination for several reasons.
First of all, in spite of the theory espoused above, no convincing literature exists that added external beam radiation improves the cure rate, if the brachytherapy quality is high. There only reference that suggested that external beam radiotherapy improved the outcome when added to brachytherapy (4), studied a cohort of very early brachytherapy patients, treated in the late 1980s, when the technique was far less advanced than today’s technique. This studied patient cohort likely had a frequent occurrence of brachytherapy “cold” spots within the prostate and as a result, it is likely that any apparent benefit caused by the addition of external beam radiotherapy to these patients resulted because the external beam radiotherapy filled in these cold spots with additional radiation. Studies of more contemporary brachytherapy patients specifically found a lack of benefit to external beam radiotherapy added to brachytherapy (3)(5).
Concern number two regarding combined brachytherapy and external beam radiotherapy is the potential increased toxicity and complication rate. The combination of external beam radiation and prostate brachytherapy treats a larger volume of rectum and bladder to high dose than does brachytherapy or external beam radiation alone. This causes more short-term rectal and bladder-related side effects and also increases the short-term bother, fatigue, length and cost of therapy. There may also be a higher risk of delayed rectal bleeding and occasionally, more serious complications with combined therapy.
Third, careful pathology review of resected prostate cancers reveals that for low to intermediate-risk patients, even when their disease spreads beyond the prostate, it is usually still contained within a 5 mm radius of the prostate. This area is normally well within the cancer-lethal radiation zone produced by a properly performed seed implant.
