Preoperative Magnetic Resonance Imaging of Prostate Cancer Predicts Pathologic Stage, Improves Outcomes
NEW YORK, May 1, 2009 — Presurgical magnetic resonance imaging (MRI) is an accurate modality for staging of prostate cancer and assessing capsular involvement, according to results of 2 studies presented at the American Roentgen Ray Society Annual Meeting in Boston.
"Preop[erative] MRI prior to prostatectomy may help improve surgical outcomes by improving oncologic outcome while minimizing side effects," presenter Dr Timothy McClure told Reuters Health.
Together with Dr Steven Raman et al at the University of California, Los Angeles, Dr McClure reviewed MRI and final pathology reports of 119 patients referred for prostate MRI prior to radical prostatectomy.
"At our institution, prostate MRI is used predominately for three roles: evaluation of men considering active surveillance, evaluation for men with a history of negative prostate needle biopsies with elevated PSA [prostate-specific antigen], and evaluation of men undergoing robotic assisted laparoscopic prostatectomy (RALP)," Dr McClure explained. "The purpose of our study was to see how accurate prostate MRI was."
According to their meeting abstract, MRI had a sensitivity of 75% and specificity of 95% for differentiating between T2 and T3 disease. Corresponding values for microscopic and/or macroscopic extracapsular extension were 71% and 86%.
"Having this knowledge should help in decision making, particularly in men contemplating radiation therapy versus surgery," the radiologist said.
In a second study, Dr McClure's group examined the benefits of MRI performed prior to RALP for guiding surgical decision making, because imaging is accurate for detecting extracapsular extension.
"The benefits of RALP are limited by loss of tactile feedback during surgery," they noted. Their goal was to see whether predetermined surgical plans with respect to resection or sparing of 38 neurovascular bundles (NVBs) in 19 men were changed following MRI.
MRI changed the plan in 10 patients. "Of patients for whom the plan was changed, 60% underwent more aggressive NBV sparing surgical technique and 40% had more conservative NVB surgical technique," the study authors reported in their meeting abstract. The rate of positive margins was 2.5%.
The team concluded that preoperative MRI "helps the urologic surgeon compensate for the lack of tactile feedback to optimize the nerve sparing technique without compromising oncological outcome."
Source: Reuters Health Information
