Journal Article

Diffusion weighted and dynamic contrast enhanced MRI as an imaging biomarker for stereotactic ablative body radiotherapy

Reynolds, Hayley M, Lau, Eddie, Siva, Shankar, Kron, Tomas, Chander, Sarat, Parameswaran, Bimal K, Finnegan, Mary E, Shaw, Mark, Roettger, Diana

2018

Overview

To explore the utility of diffusion and perfusion changes in primary renal cell carcinoma (RCC) after stereotactic ablative body radiotherapy (SABR) as an early biomarker of treatment response, using diffusion weighted (DWI) and dynamic contrast enhanced (DCE) MRI. Twelve patients were eligible for DWI analysis, and a subset of ten patients for DCE MRI analysis. DCE MRI from the second follow-up MRI scan showed correlations between the change in percentage voxels with washout contrast enhancement behaviour and the change in tumour volume ([rho] = 0.84, p = 0.004 at 12 month CT, [rho] = 0.81, p = 0.02 at 24 month CT, and [rho] = 0.89, p = 0.001 at last follow-up CT). The change in mean initial rate of enhancement and mean Ktrans at the second follow-up MRI scan were positively correlated with percent tumour volume change at the 12 month CT onwards ([rho] = 0.65, p = 0.05 and [rho] = 0.66, p = 0.04 at 12 month CT respectively). Changes in ADC kurtosis from histogram analysis at the first follow-up MRI scan also showed positive correlations with the percentage tumour volume change ([rho] = 0.66, p = 0.02 at 12 month CT, [rho] = 0.69, p = 0.02 at last follow-up CT), but these results are possibly confounded by inflammation. DWI and DCE MRI parameters show potential as early response biomarkers after SABR for primary RCC. Further prospective validation using larger patient cohorts is warranted.

• Publisher: Public Library of Science
• Subject: Care and treatment / Diagnosis / Magnetic resonance imaging / Radiosurgery / Renal cell carcinoma