Prediction of Liver Function by Using Magnetic Resonance-based Portal Venous Perfusion Imaging

Abstract

Purpose To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning. Methods and Materials Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model. Results There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT. Conclusions This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which could aid in individualizing therapy, particularly for patients at risk for liver injury after RT.

Synthetic CT for MRI-based liver stereotactic body radiotherapy treatment planning

“…Due to the superior soft tissue contrast, however, magnetic resonance imaging (MRI), long an adjunct to CT-based treatment planning, is being increasingly used as a primary tool through the use of MRI simulators (Devic 2012, Cao et al 2013), Cobalt-60-MR systems (Acharya et al 2016), and emerging integrated MR-Linacs (Lagendijk et al 2008). In order to avoid requiring both CT and MRI imaging studies on each patient and to avoid introducing image registration errors, several groups have proposed methods for MRI only treatment planning by generating CT equivalent images from MRI data (synthetic CT or MRCT) (Beavis et al 1998, Lee et al 2003, Pasquier et al 2006, Johansson et al 2011, Hsu et al 2013).…”

Implementing Radiation Dose-Volume Liver Response in Biomechanical Deformable Image Registration

“…However, assessment and analysis of localized changes in liver function can be hindered by the inability to spatially correlate the subvolumes of tissue within the liver [5, 6]. In addition, significant non-uniform changes in liver volume can compromise the correlation of the dose delivered with the longitudinal changes in the liver function observed in functional imaging.…”

“…In addition, significant non-uniform changes in liver volume can compromise the correlation of the dose delivered with the longitudinal changes in the liver function observed in functional imaging. Accurate correlation of functional imaging with delivered dose could lead to modifications of currently used liver normal tissue complication probability models to better account for the likelihood of spatially localized changes in liver function [5, 6]. …”

Index of convexity: A novel method for assessing liver functional reserve using technetium-99m-galactosyl human serum albumin liver scintigraphy

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