Study: Brachytherapy Alone Is Effective

Share this content:

It can yield good outcomes in some men with intermediate-risk prostate cancer.


Patients with intermediate-risk prostate cancer may be effectively treated with brachytherapy without supplemental pelvic radiotherapy, according to new findings.


The role of brachytherapy in treating intermediate-risk prostate cancer has been controversial. It risks undertreating extracapsular and seminal vesicle disease extension, although studies have shown that such most extracapsular extension is within 5 mm of the prostate capsule and could be treated appropriately with high-quality brachytherapy without supplemental pelvic radiotherapy.


Javier F. Torres-Roca, MD, of the H. Lee Moffitt Cancer Center at the University of South Florida in Tampa, and his colleagues examined outcomes of 88 patients with intermediate-risk prostate cancer who were treated with brachytherapy without supplemental pelvic radiotherapy; patients were followed for a minimum of 36 months (median, 57 months).


The researchers defined intermediate-risk prostate cancer as tumors with a Gleason score of 7 and/or PSA level between 10 and 20 ng/mL, and/or clinical stage greater than T2a but less than T3a.


All patients were treated with an iodine-125 transperineal seed implant with a total dose of 160 Gy delivered to the prostate, and 55 patients received pre-brachytherapy short-term androgen blockade. Biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology criteria.


Overall five-year biochemical failure-free survival was 83%, the investigators reported in Urologic Oncology (2006;24:384-390). The five-year biochemical failure-free survival was significantly decreased in patients with perineural invasion (64% vs. 89%).


The use of short-term androgen blockade did not significantly influence the biochemical outcome at five years (90% with no hormonal therapy vs. 85% with hormonal therapy). Markers of low-volume disease (i.e., number of positive cores, percentage of core involved with cancer) were not associated with biochemical failure.


Outcomes were not significantly influenced by Gleason scores 6 vs. 7, primary Gleason grades 3 vs. 4, clinical stage T1 vs. T2, number of positive cores, pretreatment PSA level less than 10 ng/mL vs. 10 ng/mL or greater, or one intermediate risk factor vs. two or more intermediate risk factors.


“The most suitable patients for brachytherapy monotherapy are pro-bably those with T1c disease and either Gleason 7 and PSA less than 10 or Gleason 6 and PSA between 10 and 20 with small volume disease,” Dr. Torres-Roca told Renal & Urology News.


“Before proceeding with brachytherapy monotherapy we would probably recommend an MRI of the prostate with an endorectal coil to rule out any extracapsular or extraprostatic extension.”

You must be a registered member of Renal and Urology News to post a comment.