Altan F Ahmed1, Naziya Samreen2,3, Joseph R Grajo2, Ivan Zendejas4, Chris L Sistrom2, Amy Collinsworth5, Ashwini Esnakula5, Jehan L Shah2, Roniel Cabrera6, Brian S Geller2, Beau B Toskich2,7. 1. Department of Radiology, University of Florida, 1600 SW Archer Road, Gainesville, FL, 32610, USA. ahmeaf@radiology.ufl.edu. 2. Department of Radiology, University of Florida, 1600 SW Archer Road, Gainesville, FL, 32610, USA. 3. Department of Radiology, Northwestern Memorial Hospital, 676 North St Clair. Ste #800, Chicago, IL, 60611, USA. 4. Department of General Surgery, Intermountain Healthcare, 5121 S Cottonwood Street, Murray, UT, 84107, USA. 5. Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Box 100275, Gainesville, FL, 32610, USA. 6. Department of Gastroenterology, University of Florida, 1600 SW Archer Road, Gainesville, FL, 32610, USA. 7. Department of Radiology, Mayo Clinic, 4500 San Pablo Road, Jacksonville, 32224, FL, USA.
Abstract
PURPOSE: To assess the radiopathologic correlation following Yttrium-90 transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC) using variable radiodosimetry to identify imaging surrogates of histologic response. METHODS: Twelve patients with HCC underwent ablative (≥ 190 Gy) and/or non-ablative (< 190 Gy) TARE delivered in a segmental, lobar, or combined fashion as a surgical neoadjuvant or bridge to transplantation. Both targeted tumor and treatment angiosome were analyzed before and after TARE utilizing hepatocyte-specific contrast-enhanced MRI or contrast-enhanced CT. Responses were graded using EASL and mRECIST criteria. Histologic findings including percent tumor necrosis and adjacent hepatic substrate effects were correlated with imaging features. RESULTS: Complete pathologic necrosis (CPN) was observed in 7/12 tumors post-TARE. Ablative and non-ablative dosing resulted in CPN in 5/6 and 2/6 tumors, respectively. Hyperintensity on T2-weighted imaging, the absence of hepatocyte-specific gadolinium contrast uptake, and plateau or persistent enhancement kinetics in the angiosome correlated with CPN and performed similarly to EASL and mRECIST criteria in predicting CPN. CONCLUSIONS: The absence of hepatocyte-specific contrast uptake, increased signal on T2-weighted sequences, and plateau or persistent enhancement in the angiosome may represent MRI surrogates of CPN following TARE of HCC. These findings correlated with EASL and mRECIST response criteria. Further investigation is needed to determine the role of these findings as possible adjuncts to conventional imaging criteria.
PURPOSE: To assess the radiopathologic correlation following Yttrium-90 transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC) using variable radiodosimetry to identify imaging surrogates of histologic response. METHODS: Twelve patients with HCC underwent ablative (≥ 190 Gy) and/or non-ablative (< 190 Gy) TARE delivered in a segmental, lobar, or combined fashion as a surgical neoadjuvant or bridge to transplantation. Both targeted tumor and treatment angiosome were analyzed before and after TARE utilizing hepatocyte-specific contrast-enhanced MRI or contrast-enhanced CT. Responses were graded using EASL and mRECIST criteria. Histologic findings including percent tumor necrosis and adjacent hepatic substrate effects were correlated with imaging features. RESULTS: Complete pathologic necrosis (CPN) was observed in 7/12 tumors post-TARE. Ablative and non-ablative dosing resulted in CPN in 5/6 and 2/6 tumors, respectively. Hyperintensity on T2-weighted imaging, the absence of hepatocyte-specific gadolinium contrast uptake, and plateau or persistent enhancement kinetics in the angiosome correlated with CPN and performed similarly to EASL and mRECIST criteria in predicting CPN. CONCLUSIONS: The absence of hepatocyte-specific contrast uptake, increased signal on T2-weighted sequences, and plateau or persistent enhancement in the angiosome may represent MRI surrogates of CPN following TARE of HCC. These findings correlated with EASL and mRECIST response criteria. Further investigation is needed to determine the role of these findings as possible adjuncts to conventional imaging criteria.