Combining Prostate MRI with Blood Test Can Avoid Unnecessary Prostate Biopsies

By MedImaging International staff writers
Posted on 01 Apr 2024

Image: Unnecessary prostate biopsies can be avoided by combining MRI of the prostate findings with PSA density (Photo courtesy of 123RF)

Prostate cancer ranks as the second most prevalent cancer among men globally. For a long time, researchers have acknowledged that not every instance of prostate cancer poses a danger that warrants immediate treatment or even a biopsy. Clinically significant prostate cancer (csPCa) is identified as cancer with a higher likelihood of becoming life-threatening, characterized by cells that appear more aggressive or cancer found outside of the prostate gland. Differentiating which cancers necessitate treatment without conducting a biopsy presents a challenge. Traditional biopsies are required to assess the aggressiveness of cancer cells, yet these procedures can be uncomfortable, invasive, and costly. Now, new research suggests that combining an MRI of the prostate with a blood test could effectively identify clinically significant prostate cancers.

Investigators from Brigham and Women’s Hospital (Boston, MA, USA) have suggested that unnecessary prostate biopsies can be avoided by combining MRI findings with prostate-specific antigen (PSA) density measurements. This novel diagnostic strategy aims to minimize the harm and healthcare costs associated with prostate biopsies. The study explored a new methodology that correlates MRI-based prostate imaging reporting and data system (PI-RADS) scores with PSA density (PSAD) to identify cancers likely to be clinically significant without biopsy data. PI-RADS assesses prostate lesions on a scale from 1 (unlikely to be clinically significant) to 5 (high likelihood of being clinically significant). PSAD is calculated by dividing the PSA level by the volume of the prostate, as determined via MRI.

Building on earlier research conducted exclusively at Brigham Women's Hospital, which suggested that PI-RADS and PSAD thresholds could eliminate the need for biopsies in up to half of the cases, the recent study analyzed data from 72 published studies encompassing over 36,000 men with prostate cancer. This analysis aimed to validate whether the initial findings could be generalized across a broader population. Results indicated that prostate biopsies might be redundant for patients with PI-RADS scores below 4 and PSAD less than 0.10 ng/ml2. Utilizing specific PI-RADS and PSAD thresholds, it was determined that 50% of biopsies could be omitted, risking the miss of only 5% of clinically significant cancers, or alternatively, skip 30% of biopsies and miss just 3% of such cancers. The research team plans to develop an easy-to-use patient-level scoring system that would enable urologists to more accurately evaluate the need for a biopsy.

"In the workup of men suspected of having prostate cancer, prostate MRI findings combined with PSA density measurement can help doctors decide which patients to biopsy," said senior author Ramin Khorasani, MD, MPH, Radiology Vice Chair for Quality and Safety at Brigham and Women’s Hospital and Mass General Brigham and Philip H. Cook Professor of Radiology at Harvard Medical School. "With this new analysis, we looked to see how MRI can help urologists decide which patients to biopsy and which patients may not need aggressive diagnosis and treatment."

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Brigham and Women’s Hospital