Pre-op MRI May Prevent ED After Prostate Surgery
Imaging Helps Surgeons Decide If Nerves Can Be Safely Spared During Surgery for Prostate Cancer
WebMD News Archive
Pre-op MRI: Study Details
The UCLA researchers evaluated 104 men who had biopsy-diagnosed prostate cancer. Reiter was the surgeon for all.
Based on the biopsy and other information, "I would say whether the plan was nerve-sparing or non-nerve-sparing surgery," he says.
Then he looked at the results of the MRIs.
For 29 of the 104 men, he changed the plan based on the MRI. ''Sometimes I did a more aggressive surgery," he says, and sometimes less aggressive, sparing some or all of the nerves.
Of the 29 whose plan changed, 17 had nerve-sparing procedures and 12 had the plan changed to non-nerve sparing surgery.
''What we found is, 30% of the time I changed what I was going to do with the neurovascular bundle based on the MRI finding," Reiter tells WebMD.
Then they looked at the positive margin rate, a measure of whether all the cancer was removed, for the entire group (the goal is negative margins). Overall, the positive margin rate was 6.7%, or seven of 104 patients. Only one of those was a man whose MRI results changed the plan to nerve-sparing surgery.
None who had their plan changed to a non-nerve-sparing procedure had positive margins.
According to Reiter, the average positive margin rate is about 20%.
Pre-op MRI: Other Opinions
The study is too small to trigger a change in practice, says Thrasher.
''Most doctors don't use the pre-op MRI because it is not sensitive enough or specific enough," he says.
He says other studies have shown a positive margin rate similar to that found in the UCLA study "and they have not used MRI."
''Based on this study, I am not sure they have proven anything," he says. "I would have to have this confirmed by a much larger, randomized study."
''I don't know if we can say we need routine MRI based on this," says Benjamin Yeh, MD, associate professor of radiology at the University of California, San Francisco, who also reviewed the study results for WebMD.
Although Reiter acknowledges the study sample is small, he says theirs confirms at least one other study that has found success with pre-op MRIs before prostate surgery.
He cautions, however, that the MRI used requires special equipment and expertise by the radiologist performing it.
About 192,280 men in the U.S. get prostate cancer annually, according to estimates from the American Cancer Society.