Improving multiparametric MR-transrectal ultrasound guided fusion prostate biopsies with hyperpolarized 13C pyruvate metabolic imaging: A technical development study
Hsin-Yu Chen, Robert A. Bok, Matthew R. Cooperberg, Hao G. Nguyen, Katsuto Shinohara, Antonio C. Westphalen, Zhen J. Wang, Michael A. Ohliger, Daniel Gebrezgiabhier, Lucas Carvajal, Jeremy W. Gordon, Peder E. Z. Larson, Rahul Aggarwal, John Kurhanewicz, Daniel B. Vigneron
Abstract
Purpose
To develop techniques and establish a workflow using hyperpolarized carbon-13 (13C) MRI and the pyruvate-to-lactate conversion rate (kPL) biomarker to guide MR-transrectal ultrasound fusion prostate biopsies.
Methods
The integrated multiparametric MRI (mpMRI) exam consisted of a 1-min hyperpolarized 13C-pyruvate EPI acquisition added to a conventional prostate mpMRI exam. Maps of kPL values were calculated, uploaded to a picture archiving and communication system and targeting platform, and displayed as color overlays on T2-weighted anatomic images. Abdominal radiologists identified 13C research biopsy targets based on the general recommendation of focal lesions with kPL >0.02(s−1), and created a targeting report for each study. Urologists conducted transrectal ultrasound-guided MR fusion biopsies, including the standard 1H–mpMRI targets as well as 12–14 core systematic biopsies informed by the research 13C-kPL targets. All biopsy results were included in the final pathology report and calculated toward clinical risk.
Results
This study demonstrated the safety and technical feasibility of integrating hyperpolarized 13C metabolic targeting into routine 1H–mpMRI and transrectal ultrasound fusion biopsy workflows, evaluated via 5 men (median age 71 years, prostate-specific antigen 8.4 ng/mL, Cancer of the Prostate Risk Assessment score 2) on active surveillance undergoing integrated scan and subsequent biopsies. No adverse event was reported. Median turnaround time was less than 3 days from scan to 13C-kPL targeting, and scan-to-biopsy time was 2 weeks. Median number of 13C targets was 1 (range: 1–2) per patient, measuring 1.0 cm (range: 0.6–1.9) in diameter, with a median kPL of 0.0319 s−1 (range: 0.0198–0.0410).
Conclusions
This proof-of-concept work demonstrated the safety and feasibility of integrating hyperpolarized 13C MR biomarkers to the standard mpMRI workflow to guide MR-transrectal ultrasound fusion biopsies.