Ascending to the Next Level

Recent studies indicate new considerations for prostate brachytherapy

Because prostate cancer and its treatment options involve the most intimate of male-related issues—erectile and urinary function—they generate a great deal of investigative scrutiny. From the physician's point of view, a prescribed treatment can be life changing, with both benefits and drawbacks for the male subject. More importantly, treatment can be lifesaving.

Treatment approaches, however, continue to raise questions, especially for physicians. Consider just one treatment innovation: brachytherapy. When is its application most appropriate? And why? Who is best served, younger or older patients? What about dose rate? At what measureable point does dose rate prove most effective or considerably debilitating, ie, toxic?

Meanwhile, clinical researchers analyze treatments and technology developers create new innovations. Those types of efforts have raised another interesting question: Would the combining of treatment approaches result in an even more powerfully positive impact?

Recent research addresses some of the above questions and has added to the existing body of knowledge. One of the most recent studies is also one of the most compelling.

Significant Trial The Androgen Suppression Combined With Elective Nodal and Dose Escalated Radiation Therapy (ASCENDE-RT) trial is a historic study. It represents a first-ever comparison between usage of low dose rate prostate brachytherapy (LDR-PB) and traditional usage of dose-escalated external beam radiation therapy (DE-EBRT). Specifically, the researchers applied the comparison in the treatment of intermediate- and high-risk patients. The results validate a new treatment concept: Both patient sets can be better served from additional application of a more-specific brachytherapy approach. Benefits could be substantial and include a longer-term, biochemical progression-free survival. For prostate cancer patients, that translates into less emotional stress related to erectile issues.

In the past, patients demonstrating an intermediate or high risk for prostate cancer were often guided toward radical prostatectomy. This surgical procedure, while effective, resulted in substantial impairment of urinary continence and erectile function. This led to consideration and/or application of regimens that involved active monitoring, hormonal treatment, or hormonal manipulation.

Eventually, brachytherapy entered into this evolving treatment territory. This much more attractive option involved the implantation of comparatively miniscule radioactive "seeds" directly into the prostate. This approach would soon be deemed an effective treatment with minimal side effects, particularly for low-risk prostate cancer patients.

In the meantime, intensity-modulated radiation therapy (IMRT) began to loom large. Indeed, its application—combined with specific dose-application considerations—may eventually supplant brachytherapy, at least in some cases. Circa the late 1990s and early 2000s, this resulted in a reconsideration of offering brachytherapy.

David Beyer, MD, FASTRO, medical director of the Cancer Centers of Northern Arizona in Sedona and immediate past chair of the ASTRO board of directors, says, "We were very excited about the promise of IMRT. What made it so attractive was that it allowed for dose escalation. Oncologists and urologists—I include myself—thought that dose escalation with IMRT alone was good enough."

Data made available via ASCENDE-RT led to another reconsideration.

"The data show that the decision to do less brachytherapy and more IMRT was wrong," Beyer says.