Agreement between Competing Imaging Measures of Response of Hepatocellular Carcinoma to Yttrium-90 Radioembolization

Abstract

Purpose There are currently at least 6 major competing criteria that are used to determine response to 90Y and other liver-directed therapies including: a) RECIST, b) WHO, c) volumetric, d) 2D EASL, e) 3D EASL, f) functional diffusion weighted (DW) MR imaging. Our purpose was to evaluate the agreement between these competing tumor response classification schemes based on quantitative measurements of tumor size, necrosis, and changes in water mobility. Materials/Methods In this retrospective study, 20 HCC patients underwent 90Y radioembolization. The patients’ tumor burden before and 3–6 months after treatment was assessed with MRI. The percent change in size of tumors was used to classify patients into response categories. Kappa and agreement statistics were used to compare the concordance between the different criteria. Results Conventional size criteria (RECIST, WHO, and volumetric) all had a substantial level of agreement (kappa statistics from 0.76 to 0.78) when classifying patients into response categories. However, the conventional size criteria in relation to either 2D or 3D EASL had only slight to moderate concurrence with kappa statistics as low as 0.06. 2D EASL criteria and functional DW MR imaging resulted in the highest response rates, 11/20 (55%) and 15/20 (75%) respectively, while conventional size criteria produced lower response rates. Conclusions Classification of HCC response to 90Y radioembolization was related to which of the competing criteria are used. We recommend that anatomic imaging criteria be used as the primary method to determine response and functional imaging criteria be used as a complementary secondary method.

Which Response Criteria Best Help Predict Survival of Patients with Hepatocellular Carcinoma Following Chemoembolization? A Validation Study of Old and New Models

“…Such responses appear as arterially nonenhanced areas within treated lesions at dynamic CT or MR imaging ( 2 ). Researchers in recent studies have reported that the EASL criteria provide a signifi cant anatomic response and are useful prognosticators of clinical outcomes in HCC patients following chemoembolization or yttrium 90 radioembolization ( 11,18 ). With the EASL guidelines, a bidimensional method is used to estimate tumor load, on the basis of WHO size criteria.…”

Image-Guided Personalized Predictive Dosimetry by Artery-Specific SPECT/CT Partition Modeling for Safe and Effective 90Y Radioembolization

“…Overall response according to the Response Evaluation Criteria in Solid Tumors (version 1.1), the criteria of the World Health Organization, and the 2-dimensional criteria of the European Association for the Study of the Liver were used to evaluate 90 Y radioembolization as a part of comprehensive multimodality therapy for inoperable HCC, without regard to planning target volumes (28,30).…”

Unresectable Hepatocellular Carcinoma: MR Imaging after Intraarterial Therapy. Part II. Response Stratification Using Volumetric Functional Criteria after Intraarterial Therapy

“…Volumetric assessment of tumor anatomy and function by using diffusionweighted MR imaging and enhancement after contrast material administration has been successfully applied in the liver (22,23). Specifically, an increase in apparent diffusion coefficient (ADC) obtained from diffusion-weighted imaging after therapy has been shown to be associated with tissue edema, fibrosis, necrosis, and apoptosis (11,(24)(25)(26)(27). A decrease in contrast enhancement after intraarterial therapy is indicative of disruption of tumor blood supply and has increased substantially.…”