MRI Plus Systematic Sampling Ups First-Time Prostate-Biopsy Hits

In biopsy-naive men, combining MRI with systematic sampling of the imaged lesions increases detection of clinically significant prostate cancer, according to California-based researchers.

As Dr. Leonard S. Marks told Reuters Health by email, “One must do both MRI-targeted and template-systematic biopsies together to maximally find cancer. Either method alone will miss a fair number of the cancers.”

In a paper online June 12 in JAMA Surgery, Dr. Marks and colleagues at the University of California, Los Angeles, observe that “the optimal method for use of MRI-guided biopsy is not yet clear.”

To investigate, the researchers studied 300 patients, of whom 248 had MRI-visible lesions and the remaining 52 had negative MRI results.

At the same sitting, those with visible lesions underwent both systematic (12 cores) and targeted biopsy (six cores). There were three procedures: a systematic biopsy, an MRI-lesion biopsy targeted by cognitive fusion and thirdly an MRI-lesion biopsy targeted by software fusion. Those with no MRI-visible lesions underwent a 12-core systematic biopsy.

Combining systematic and targeted biopsy results gave an overall cancer-detection rate (CDR) of 70%. This varied from 47% when using cognitive fusion biopsy alone, to approximately 60% when using systematic biopsy or either fusion method alone.

Systemic sampling in the group with no MRI-visible lesions gave a CDR of 15%.

“Discordance of tumor locations suggests that the different biopsy methods detect different tumors,” say the researchers. “Thus, combining targeting and systematic sampling provide greatest sensitivity for detection of clinically significant prostate cancer.”

Dr. Marks added, “MRI before biopsy is important to guide the biopsy and estimate risk of a serious cancer. MRI should be employed even before a man’s first prostate biopsy.”

Moreover, he said, there is “No need to wait and see if conventional biopsy shows the cancer, then use targeted biopsy as a backup.”

In an accompanying editorial, Drs. Ahmad Shabsigh and Cheryl T. Lee of Ohio State University Wexner Medical Center, in Columbus, note that the study shows that “relying on targeted biopsy alone is suboptimal” and “if the urologist does not have a fusion machine, cognitive biopsy is still essential.”

Dr. Lee added in an email to Reuters Health that the research addresses “an important issue about the role of traditional systematic prostate biopsy in the era of MRI-guided sampling. This important study affirms the importance of MRI-guided biopsy in the detection of clinically significant prostate cancer but also demonstrates additional value in the concomitant use of systematic biopsy.” – Med Scape