OBJECTIVE: To evaluate the agreement in volumes of prostate tumors determined on multiparametric MRI (mpMRI) and histologic assessment, using detailed software-assisted co-registration.
MATERIALS AND METHODS: 37 patients who underwent 3T mpMRI (T2WI, DWI/ADC, DCE) were included. A radiologist traced the borders of suspicious lesions on T2WI and ADC and assigned a suspicion score (SS) from 2-5; a uro-pathologist traced borders of tumors on histopathologic photographs. Software was used to co-register MRI and 3D digital reconstructions of RP specimens and compute imaging and histopathologic volumes. Agreement in volumes between MRI and histology was assessed using Bland-Altman plots and stratified by tumor characteristics.
RESULTS: Among 50 tumors, mean difference and 95% limits of agreement on MRI relative to histology were -32% (-128% to +65%) on T2WI and -47% (-143% to +49%) on ADC. For all tumor subsets, volume under-estimation was more marked on ADC maps (mean difference ranging from -57% to -16%) than T2WI (mean difference ranging from -45% to +2%). 95% limits of agreement were wide for all comparisons, with lower 95% limit ranging between -77% and -143% across assessments. Volume under-estimation was more marked for tumors with Gleason score ≥7 or MRI SS 4 or 5.
CONCLUSION: Volume estimates of PCa using MRI tended to substantially under-estimate histopathologic volumes, with wide variability in extent of under-estimation across cases. These findings have implications for efforts to use MRI to guide risk assessment.
Written by:
Le Nobin J, Orczyk C, Deng FM, Melamed J, Rusinek H, Taneja SS, Rosenkrantz AB. Are you the author?
Division of Urologic Oncology, Department of Urology, New York University Langone Medical Center, New York, NY; Department of Urology, University Hospital of Lille, Lille, France.
Reference: BJU Int. 2014 Mar 27. Epub ahead of print.
doi: 10.1111/bju.12750
PubMed Abstract
PMID: 24673731
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