Planning radical prostatectomies without first performing biopsies may be possible for well-selected patients, with surgeons able to use just radiographic scans as guidance.

Researchers at the Technical University of Munich School of Medicine make this claim in a new study that utilized images from multiparametric magnetic resonance imaging (mpMR) of the prostate and prostate-specific membrane antigen positron emission tomography (PSMA-PET). They suggest that such an approach may help patients avoid invasive prostate biopsies, which are often uncomfortable, costly and come with potential risks.

They tested their technique on 25 men with Grade Group 2 or higher prostate cancer on postoperative pathology. On a per-patient basis, sensitivity and positive predictive value for identifying prostate cancer were 100% with both modalities, according to Renal and Urology News.

“Results of the current retrospective case series were promising and showed that, in patients with a high suspicion of [prostate cancer] in mpMR and PSMA-PET, avoidance of prostate biopsy prior to RP might represent a valid option in well-counseled, selected patients,” wrote Dr. Valentin Meissner, of the Technical University of Munich School of Medicine, in a statement.

While successful, the authors acknowledge that the small sample size and retrospective nature of the study limits its validity. They add that the technique should not be seen as a standard procedure right now and that a prospective evaluation within an ethically approved clinical trial is required.

Dr. Sanoj Punnen, associate professor and vice chair of research in the department of urology at the Miller School of Medicine at the University of Miami, says that MR readings can also vary, and false positives are a possibility to consider. “The biopsy provides more information about the true grade and extent of tumor within the prostate, and without this we could underestimate or overestimate the burden of cancer, which could lead to misguided management.”

Dr. Michael Leapman, clinical program leader of the Prostate & Urologic Cancers Program at the Yale Cancer Center, adds that the findings should be read with caution, “as the consequences of exposing even one patient without cancer to prostatectomy is substantial, regardless of how they are counseled. Moreover, widespread use of PSMA-PET and prostate MR raises questions about long-term cost effectiveness and sustainability.”

A recent study in Canada found that performing MR before targeted biopsies was at least as effective as the standard ultrasound-guided transrectal approach for detecting cancers. It also helped spare a large percentage of patients with slowly progressing cancers who did not require unnecessary biopsies by 55%. Those who did undergo biopsies also required significantly fewer samples to be taken, thereby reducing recovery time and the prevalence of common adverse events.

The findings for the study here were published in European Urology.