Higher-energy BPH laser therapy leads to greater PSA drop

Last Updated: 2016-04-04

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - Treating benign prostatic hyperplasia (BPH) with higher-energy lasers may lower prostate-specific antigen (PSA) more, according to new research.

Increasing the energy usage per gram of prostate, up to 7 kilojoules per cubic centimeter (kJ/cc) using photo-selective vaporization of the prostate (PVP), reduced PSA up to 83% at six, 12, and 24 months, but did not affect functional outcomes two years later, the authors reported online March 11 in the British Journal of Urology (BJU) International.

"It is safe to suggest that energy delivery should be maintained above a level of 3 kJ/cc, and that PSA reduction of at least 50% at one year may be associated with good long-term outcomes," they wrote.

"The key finding is that, in order to remove obstructing prostate tissue, certain amounts of energy result in various PSA reductions, which correlate to the treatment. Using more energy did not correlate with more complications," Dr. Kevin C. Zorn, of the University of Montreal in Quebec, Canada, told Reuters Health by phone.

"Treatment failure within two years trended higher in those being treated with less energy. The cutoff we found was that more than 3 kJ/cc related to low or no retreatment at two years," he said.

Dr. Zorn and his colleagues retrospectively reviewed data from 440 patients in their sixties and seventies treated for BPH with Greenlight laser XPS 180W LBO PVP at seven medical centers in North America and Europe.

The researchers stratified patients into four arbitrarily chosen energy density groups according to the intraoperative energy delivered and the prostate volume, which ranged overall from 37 to 100 cc, according to preoperative trans-rectal ultrasound. Group 1 received <3 kJ/cc, group 2 received 3 to 5 kJ/cc, group 3 received 5 to 7 kJ/cc, and group 4 received 7 or more kJ/cc.

At 24 months, PSA dropped 51%, 61%, 79%, and 83% for energy density groups of <3, 3 to 5, 5 to 7 and 7 or more kJ/cc, respectively (p=0.01 or less), even after accounting for baseline confounders.

Energy density was not associated with higher complication rates, including hematuria, stricture, refractory urinary retention, incontinence, urinary tract infection and conversion to transurethral resection of the prostate (TURP). Functional outcomes at two years were comparable between groups (p>0.05 for all) and retreatment rates were similar (p=0.36).

Limitations of the study included non-uniform reporting of complications, unbalanced number of patients in each group, arbitrary energy groupings, and relatively short follow-up.

"The purpose of the study was to try to universalize a minimum energy requirement in order to do good surgery. Our results will help guide new and perhaps intermediate users with a certain benchmark of energy to tailor the treatment to the size of the patient's prostate to ensure better outcomes," Dr. Zorn said.

Dr. Daniel H. Williams IV, of the University of Wisconsin School of Medicine and Public Health in Madison, told Reuters Health by email, "At the root of the surgical treatment of BPH remains the question of how much tissue needs to be removed in order to improve a man's urination."

"This study suggests that, in the short term, it may not be necessary to remove all of the adenoma in order to achieve satisfactory post-operative outcomes, especially in larger prostates," said Dr. Williams, who was not involved in the study. "This study also suggests that postoperative complication rates may not be dependent upon gland size or amount of tissue removed."

"Longer follow-up is needed to truly affect patient care, and it remains unclear if these results can be applied to all practicing urologists. However, these findings add to the growing body of literature that in experienced hands, photoselective vaporization of the prostate remains a safe and effective treatment for BPH with urinary obstruction," he advised.

The authors reported no funding or relevant disclosures.

SOURCE: http://bit.ly/1RXYmwA

BJU Int 2016.