Patient cohort and specimen octants generation

Data were collected from 11 patients who had TRUS-guided biopsy-proven prostate cancer and elected to have radical prostatectomy received MRI/MRSI prior to their surgical procedure. The average PSA level of these patients was 9.4 (0.5-29.0) ng/mL. After radical prostatectomy, each prostate specimen was fixed in formalin and high-resolution MR images were obtained prior to whole mount sectioning of the prostate. Axial sections (3 mm) from the specimen were made using an in-house prostate slicer. Hematoxylin-eosin (H&E) staining was performed on 50-µm sections from each of the slides. Digital images of both the slice specimens and the pathologic slides were obtained, which were used to match to the MR images. After discarding unusable slices, the remaining 28 slices were subdivided into octants. This resulted in 223 octants (1 octant was not usable). A GS was given to each of the octant by a pathologist. In our data set, GSs range from 0 to 8, with 0 indicating no cancer cell identified, GS ⩽ 6 indicating indolent (slow-growing or nonaggressive), and GS > 6 indicating aggressive cancer. In Figure 1, we show the distribution of GS in our data set.

Gleason score histogram.