Patients who receive an intermediate score of the Prostate Imaging Reporting and Data System (PI-RADS) scale, or PIRADS 3, have a substantial chance of developing clinically significant prostate cancer, new research shows.
However, PI-RADS v2 doesn’t provide guidelines to aid in clinical decision-making for patients with intermediate scores, making it more difficult to develop a timely plan for care, said Fatima Salah, MD, a clinical fellow at Brigham and Women’s Hospital in Boston, and colleagues in her RSNA 2020 session, “Understanding Prostate MR PI-RADS 3: A Longitudinal Study.”
“Those patients are more challenging,” Dr. Salah said. “PI-RADS 3 is a common category but it’s problematic because there are no specific guidelines for what the next steps should be.”
PI-RADS is used to standardize interpretation of prostate MRI, improve early diagnosis and treatment and reduce unnecessary biopsies. In the PI-RADS scale, each lesion is assigned a score from 1 to 5 indicating the likelihood of clinically significant cancer.
PI-RADS 1: clinically significant cancer is highly unlikely to be present; PI-RADS 2: clinically significant cancer is unlikely to be present, PI-RADS 3: intermediate the presence of clinically significant cancer is equivocal; PI-RADS 4: clinically significant cancer is likely to be present; PI-RADS 5: clinically significant cancer is highly likely to be present.
Typically, when a patient receives a PI-RADS 3 rating the next step is to speak with the person’s doctor about other risk factors and evaluate possible next steps. But that can vary from patient to patient.
“Practice variability can create confusion, diagnosis delay or unnecessary procedures,” Dr. Salah said.
PI-RADS 3 Patients Require Plan for Care Management
Dr. Salah and colleagues sought to determine the incidence of clinically significant prostate cancer in men with a PI-RADS v2 assessment category 3 based on their prostate multiparametric MRI.
The team examined all prostate MRIs exams at Brigham and Women’s Hospital performed between 2014 and 2019 with a PI-RADS 3 score. Out of 3,238 MRI exams, 423 patients had a PI-RADS 3 score.
The retrospective study found that 292 men with a PI-RADS 3 underwent 713 procedures. Of those patients, 90% had a biopsy, 8% had a prostatectomy and 2% underwent a transurethral resection.
Of the 292 patients with available follow up pathology and medical reports, 26% were diagnosed with clinically significant prostate cancer, 51% had non-clinically significant prostate cancer and 23% had no prostate cancer.
Results also showed that the mean time from MRI to diagnosis in the patients who were determined to have clinically significant prostate cancer was nine months.
“These patients are ending up with clinically significant prostate cancer not in five or 10 years, but in a short time,” Dr. Salah said. “This means that perhaps we should be more aggressive in their care management.”
Based on these findings, Dr. Salah would like to work with other radiologists to develop a plan for managing the care of patients at Brigham and Women’s Hospital who receive a PI-RADS 3 score.
“We hope to emphasize that we need to work on guidelines for PI-RADS 3 patients specifically to standardize their care,” Dr. Salah said.
For More Information
View the RSNA 2020 session Understanding Prostate MR PI-RADS 3: A Longitudinal Study — SSGU07 at RSNA2020.RSNA.org.