Utility of Multi-Parametric Quantitative Magnetic Resonance Imaging for Characterization and Radiotherapy Response Assessment in Soft-Tissue Sarcomas and Correlation With Histopathology

Conclusion: Fat fraction on MRI corresponded to fat content on histology and therefore contributes to lesion characterization. Measurement repeatability was excellent for ADC; this parameter increased significantly post-radiotherapy even in disease categorized as stable by size criteria, and corresponded to cellularity on histology. ADC can be utilized for characterizing and assessing response in heterogeneous retroperitoneal sarcomas. Introduction Soft-tissue sarcomas are often highly heterogeneous tumors with variable components that can include cellular tumor, fat, necrosis, and cystic change. In many soft-tissue sarcoma sub-types, post-treatment changes often cannot be described by standard size criteria (response evaluation criteria in solid tumors, RECIST 1.1), as components within responding tumors may not shrink, or may increase in size, after radiotherapy (1, 2). Additionally, where systemic therapies alone are administered in non-resectable disease (3) or where radiotherapy with systemic therapies are used as an alternative to surgery (4), sensitive and reliable non-invasive methods for response assessment are needed. Magnetic resonance imaging (MRI) enables non-invasive assessment of the whole tumor, and a multi-parametric approach can be used to quantify tumor components and assess changes within these components as tumors respond to treatment. Diffusion-weighted MRI (DW-MRI) assessment of tumor cellularity and dynamic contrast-enhanced MRI (DCE-MRI) assess...
Source: Frontiers in Oncology - Category: Cancer & Oncology Source Type: research