Non-contrast MRI may enhance early detection of prostate cancer

Results from the PROSA trial published in European Radiology suggest that non-contrast MRI may facilitate early detection of clinically significant prostate cancer (csPCa) and simultaneously lower the occurrence of unnecessary biopsies and detection of clinically insignificant disease.¹

“Performing non-contrast MRI reduces the exam acquisition time and improves operational logistics, lowering costs and side effects. In addition, many of the practical difficulties associated with multi-parametric MRI with contrast medium injection are removed, and this makes the execution of the examination simplified and ideally possible in a greater number of centers.”

Noting the paradox between a reported 40% occurrence of overdiagnosis with a prostate-specific antigen (PSA) testing-only approach to prostate cancer screening and potential cost savings of early disease detection, researchers are currently exploring an alternative approach to prostate cancer screening.

In an ongoing prospective randomized study, researchers are comparing 1 group of 175 men who had biparametric MRI (bpMRI) for prostate cancer screening regardless of PSA values to a group of 173 men in whom bpMRI was reserved only for those who had PSA values greater than 3 ng/mL or 2.5 ng/mL if they had a family history of prostate cancer. Sixty-one men in the second treatment arm had bpMRI, according to the study.

Preliminary results from the study showed that biopsy was recommended for 11.4% (20/175) of the patients in the first treatment arm (bpMRI screening regardless of PSA values) in comparison to 5.2% (9/173) of the second treatment group (reserving bpMRI for patients with elevated PSA values). Out of 10 biopsies performed in the first group, researchers noted six cases of prostate cancer (including four cases of csPCa). Out of six biopsies performed in the second group, the study authors found two cases of clinically insignificant prostate cancer.

The researchers added that 4 of the 6 men diagnosed with the prostate cancer in the first treatment group (including three out of four men who had csPCa) had normal PSA levels.

“These men, without those screening MRIs, probably would not have been diagnosed with prostate cancer at such an early stage,” wrote Valeria Panebianco, MD, who is affiliated with the Department of Radiological Sciences, Oncology and Pathology at Sapienza University in Rome, Italy, and colleagues.¹

The study authors explained that the MRI protocol included high-resolution T2-weighted imaging in axial and coronal planes as well as diffusion-weighted imaging (DWI). The mean MRI scan time in the study was 15 minutes, according to the researchers.

“Performing non-contrast MRI reduces the exam acquisition time and improves operational logistics, lowering costs and side effects,” pointed out Panebianco and colleagues. “In addition, many of the practical difficulties associated with multi-parametric MRI with contrast medium injection are removed, and this makes the execution of the examination simplified and ideally possible in a greater number of centers.”¹

In regard to study limitations, the researchers emphasized that the findings are preliminary data from a single tertiary referral center. They also conceded a low number of prostate cancer occurrences in both arms of the study.

Reference

1. Messina E, La Torre G, Pecoraro M, et al. Design of a magnetic resonance imaging-based screening program for early diagnosis of prostate cancer: preliminary results of a randomized controlled trial-Prostate Cancer Secondary Screening in Sapienza (PROSA) [published online ahead of print August 10, 2023]. Eur Radiol. doi: 10.1007/s00330-023-10019-1