Unresectable Hepatocellular Carcinoma: MR Imaging after Intraarterial Therapy. Part I. Identification and Validation of Volumetric Functional Response Criteria

Abstract

Purpose:To identify and validate the optimal thresholds for volumetric functional MR imaging response criteria to predict overall survival after intraarterial treatment (IAT) in patients with unresectable hepatocellular carcinoma (HCC). Materials and Methods:Institutional review board approval and waiver of informed consent were obtained. A total of 143 patients who had undergone MR imaging before and 3-4 weeks after the first cycle of IAT were included. MR imaging analysis of one representative HCC index lesion was performed with proprietary software after initial treatment. Subjects were randomly divided into training (n = 114 [79.7%]) and validation (n = 29 [20.3%]) data sets. Uni-and multivariate Cox models were used to determine the best cutoffs, as well as survival differences, between response groups in the validation data set. Results:Optimal cutoffs in the training data set were 23% increase in apparent diffusion coefficient (ADC) and 65% decrease in volumetric enhancement in the portal venous phase (VE). Subsequently, 25% increase in ADC and 65% decrease in VE were used to stratify patients in the validation data set.Comparison of ADC responders (n = 12 [58.6%]) with nonresponders (n = 17 [34.5%]) showed significant differences in survival (25th percentile survival, 11.2 vs 4.9 months, respectively; P = .008), as did VE responders (n = 9 [31.0%]) compared with nonresponders (n = 20 [69.0%]; 25th percentile survival, 11.5 vs 5.1 months, respectively; P = .01). Stratification of patients with a combination of the criteria resulted in significant differences in survival between patients with lesions that fulfilled both criteria (n = 6 [20.7%]; too few cases to determine 25th percentile), one criterion (n = 9 [31.0%]; 25th percentile survival, 6.0 months), and neither criterion (n = 14 [48.3%]; 25th percentile survival, 5.1 months; P = .01). The association between the two criteria and overall survival remained significant in a multivariate analysis that included age, sex, Barcelona Clinic for Liver Cancer stage, and number of follow-up treatments. Conclusion:After IAT for unresectable HCC, patients can be stratified into significantly different survival categories based on responder versus nonresponder status according to MR imaging ADC and VE cutoffs.q RSNA, 2013

Quantitative volumetric functional MR imaging: an imaging biomarker of early treatment response in hypo-vascular liver metastasis patients after yttrium-90 transarterial radioembolization

“…The presented data by Chapiro et al [29] provided multilayer proof of the precision of 3D quantitative perfusion and diffusion-weighted MR imaging when correlated with pathologic examination as a standard of Ref. [14][15][16]. Our data demonstrated that volumetric analysis of functional MR imaging during the hepatic arterial and portal venous phase is superior because it There were several limitations to this study.…”

“…On the contrary, anatomic metrics did not show any significant change in the responders or non-responders after therapy. Our results suggest that these potential novel functional MRI techniques can stratify patients as responders and non-responders early (1 month) after TARE, even before changes in tumor size and/or morphologic characteristics occur [16,25].…”

“…Diffusion-weighted imaging (DWI) and the quantifiable apparent diffusion coefficient (ADC) detect motion of water within tumor tissues, which has been useful in tumor detection, characterization, and in monitoring response to treatment [11][12][13]. Previous studies have demonstrated that volumetric functional MR imaging can help in accurately assessing tumor response after loco-regional therapy (LRT) in patients with HCC, neuroendocrine liver metastases (NELM), and islet cell liver metastases (ICLM) [14][15][16]. The objective of this study was to assess the value of quantitative volumetric biomarkers to evaluate early (1 month) response after 90 Y-radioembolization in hypo-vascular liver metastasis, and compare those metrics to current metrics including RECIST, mRECIST, and EASL.…”

Multimodality 3D tumor segmentation in HCC patients treated with TACE

“…Importantly, volumetric techniques were shown to have a strong influence on how tumor response is classified and in some studies, the classification of patients as responders or nonresponders was shown to differ between 3D and non-3D techniques in up to one-third of the analyzed cases (12,13). Furthermore, 3D quantitative techniques have been repeatedly shown as beneficial in identifying tumor response more accurately, primarily because they include the whole tumor tissue into the analysis (14,15) . For assessment of radiological response after TACE, 3D volumetric measurement has a strong clinical impact to be able to accurately measure what part of the lesion is necrotic and viable(16).…”

Can volumetric ADC measurement help predict response to Y90 radioembolization in HCC?

“…By imaging, partial response to therapy was defined from baseline as a ‡30% reduction for the maximal diameter in the transverse plane according to the RECIST criteria; as a ‡30% reduction for the maximal diameter of tumor enhancing portions in the transverse plane according to mRECIST criteria and as a reduction ‡65% of the tumor volume (volumetric transformation of RECIST criteria) [1,2,16]. Complete response was defined as the absence of visible tumor (for RECIST and Volume criteria) or the absence of enhancing tumor portions (for mRECIST).…”