MRI grading system helps simplify prostate cancer assessment

A team of national researchers has identified a set of multiparametric MRI-based guidelines and clinical features which can help clinicians easier determine a patient’s risk their prostate cancer will spread, according to a Jan. 22 study published in Radiology.

Extraprostatic extension (EPE) occurs when a tumor extends beyond glands in the prostate and is associated with an increased risk of biochemical recurrence, metastatic disease and lower cancer-specific survival after prostatectomy, wrote first author, Sherif Mehralivand, with University Medical Center in Mainz, Germany, and colleagues.

This new grading system, however, may allow for earlier detection and better treatment for these patients.

“The system adds additional diagnostic value to clinical parameters and provides a graded quantifiable risk assessment of pathologic EPE,” the authors wrote. “It is based on only a few imaging features, making it easy to teach, and it should be relatively easy to implement.”

The team retrospectively analyzed 553 men (mean age of 60) who underwent 3T MRI followed by robotic-assisted laparoscopic radical prostatectomy—125 men had pathologically-confirmed EPE.

They determined EPE visible with MRI, curvilinear contact length greater than 1.5 cm and capsular bulge and irregularity were all the main features associated with a higher risk of EPE. These markers made up their four-point grading system. Grade 0 is no suspicion of pathologic EPE; grade 1 included curvilinear contact length or capsular bulge and irregularity, grade 2 included both features and grade 3 meant MRI-verified EPE or tumor expansion past the prostate.

As the grades went up, so did the detection of pathologic EPE. For grades 1,2 and 3 those rates were 24 percent, 38 percent and 66 percent, respectively.

Additionally, combining clinical features with the MRI-based EPE grading system predicted EPE better than MRI alone (AUC of 0.81 compared to 0.77).