LI-RADS Treatment Response Algorithm: Performance and Diagnostic Accuracy With Radiologic-Pathologic Explant Correlation in Patients With SBRT-Treated Hepatocellular Carcinoma

Updates on LI‐RADS Treatment Response Criteria for Hepatocellular Carcinoma: Focusing on MRI

“…23 In this study, decreasing APHE after treatment highly correlated with complete pathologic necrosis, although persistent posttreatment APHE was still seen in 45% of tumors that were completely necrotic on pathology. 23 Interreader agreement was fair (κ = 0.22) for LR-TRA categorization of HCC treated with SBRT. Additionally, LI-RADS TRA was able to predict complete (sensitivity = 71%-86%, specificity = 85%-96%, NPV = 85%-96%) and incomplete tumor necrosis (sensitivity = 88%-96%, specificity = 71%-93%, PPV = 88%-92%, with LR-TR equivocal lesions considered viable).…”

“…To date, there is only one study evaluating the diagnostic performance of the LI‐RADS TRA in assessing HCC viability after SBRT using radiology–pathology concordance 23 . In this study, decreasing APHE after treatment highly correlated with complete pathologic necrosis, although persistent posttreatment APHE was still seen in 45% of tumors that were completely necrotic on pathology 23 .…”

“…5). Emerging data suggest that enhancement and size of the treated lesion should gradually decrease over time if nonprogressing or nonviable, unlike viable tumors in which an increase in enhancement and/or size is imaging biomarkers for progression and should warrant discussion at multidisciplinary conference [21][22][23] (Fig. 6).…”

“…This natural history is different than LR-TR equivocal categorization of lesions treated with nonradiation-based treatment, which frequently progress over time and often require retreatment. [23][24][25][26] This difference is likely a result of the different mechanisms of cell death induced by radiation vs. nonradiation therapies.…”

“…19 One way to distinguish clinically significant viable tumor from expected postradiation changes is to evaluate change and size of APHE over time, specifically, if the area of questionable APHE and washout is new when compared with pretreatment or preceding posttreatment imaging. On MRI, new APHE or increasing intensity of enhancement over time on posttreatment imaging follow-up studies is an important feature suggesting local recurrence and should prompt classification of a lesion as LR-TR viable 11,20,23 (Fig. 6).…”