(UroToday.com) The 2022 GU ASCO Annual meeting included a prostate cancer session featuring work from Dr. Tarik Benidir and colleagues presenting results of their study assessing prostate MRI reports and concordance with radical prostatectomy specimens with regards to considerations for focal therapy when describing MRI diagnostic findings. Focal therapy for prostate cancer is becoming an attractive option for men seeking treatments that minimize the morbidity of whole gland therapy. Prostate MRI reports should include lesion location, presence of bilateral extension, and presence of multifocality as these radiographic features are essential in selecting appropriate candidacy. The aim of this study was to evaluate concordance of disease between MRI and final pathology reports.
This study was a retrospective review of pathology reports from radical prostatectomies performed at the Cleveland Clinic between 2019-2021, in patients who also underwent pre-operative prostate MRI. The number and locations of PI-RADS ≥ 3 lesions described in MRI reports were compared against the radical prostatectomy findings and assessed for disease concordance in terms of lesion location, extent (unilateral vs. bilateral extent), and/or the presence of tumor multifocality.
A total of 1,593 patients underwent radical prostatectomy, among which 416 (26.1%) had a preoperative prostate MRI. The majority (65.3%; n = 273/416) of MRI’s reported a single PI-RADS > 3 lesion, 51/416 (12.3%) had negative MRI’s and 22.1% (92/416) described >2 PI-RADS ≥ 3 lesions. A total of 370 MRI reports had detailed descriptions of their MRI and path reports for comparative analysis:
MRI and final path tumor concordance with respect to unifocal extent or multifocality were low (34%). When a single PI-RADS > 3 lesion was described, concordance with final path was 37.6% as compared to 55.6% when >2 lesions were described (p = 0.006). Discordant findings at final path included the presence of tumor multifocality (80.7%) or the extent of a unifocal lesion (19.3%). Lesions crossing the midline were uncommonly reported on MRI (16%). When prostate midline assessment was included in the evaluation of lesion extent, the degree of concordance with final pathology improved from 33.3% to 64.2% (p = 0.038). Predictors of MRI-radical prostatectomy concordance are as follows:
- Higher pathological grade groups (p <0.001)
- Increasing PI-RADS scores (p < 0.001)
- Zone of MRI visible lesion (PZ > TZ, p = 0.013)
- Number of lesions described (>1 vs <=1, p = 0.003)
- Description of lesions crossing the midline (p = 0.025)
- Larger MRI lesions size (<1 cm, 1-2cm, >2cm, p = 0.06)
Dr. Benidir concluded his presentation assessing concordance of MRI and radical prostatectomy specimens with the following take-home messages:
- Prostate MRI reports have a large discordance with radical prostatectomy reports
- Tumor multifocality and/or unifocal disease crossing the midline may not hold significant meaning if the disease is ultimately organ confined and the treatment is aimed at the whole gland
- However, in the context of focal therapy, these findings are of germane importance
- Radiologists are encouraged to consider focal therapy as a treatment strategy when describing MRI findings and acknowledge the importance of tumor multifocality/bilaterality in this context
Presented by: Tarik Benidir, MD, Cleveland Clinic Glickman Urological Institute, Cleveland, OH
Co-Authors: Martin Hofmann, Christopher Weight, Eric A. Klein, Andrei Purysko
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia, @zklaassen_md on Twitter during the 2022 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, Thursday, Feb 17 – Saturday, Feb 19, 2022