Improved imaging-pathology correlation with MR imaging-derived, 3D-printed, patient-specific whole-mount molds of the prostate.

Abstract

44 Background: A critical requirement for imaging-pathology correlation is adequate image registration. Since the prostate is deformable, sectioning the gland in a plane similar to imaging is challenging. To improve the in vivo imaging and ex vivo histology image registration, 3D-printed, patient-specific, MRI-derived molds (PSMs) for whole-mount processing have been proposed. This study compared the anatomical registration of preoperative MRI and prostate whole-mounts obtained with PSMs versus conventional whole-mount sectioning (WMS). Methods: Based on an a priori power analysis, 50 men who underwent 3T prostate MRI followed by radical prostatectomy were included. Two blinded and independent readers (R1, R2) outlined the contours of the gland and of the tumor in the MRI using regions of interest (ROIs). These were compared with the ROIs from the whole-mount histology, the reference standard, using PSMs in the study group (n=25) or conventional WMS in the control group (n=25). The spatial overlap across the MRI and histology data sets was calculated using the Dice similarity coefficient (DSC) for the prostate overall and tumor. Results were compared using Wilcoxon rank sum test. Results: The MRI-histopathology anatomical registration for the prostate gland overall and the tumor were significantly superior with the use of PSMs than with the use of WMS for both readers (Table). Conclusions: The use of PSMs for prostate specimen whole-mount sectioning provides significantly superior anatomical registration of in vivo multiparametric MRI and ex vivo prostate whole-mounts than conventional WMS. The use of PSMs should facilitate the exchange of information across imaging and pathology required for research and patient care. [Table: see text]