New OPTN/UNOS Classification System for Nodules in Cirrhotic Livers Detected with MR Imaging: Effect on Hepatocellular Carcinoma Detection and Transplantation Allocation

Abstract

Purpose To assess the effect of the new Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) policy on hepatocellular carcinoma (HCC) detection and liver transplant allocation in patients with cirrhosis undergoing dynamic contrast material–enhanced liver magnetic resonance (MR) imaging. Materials and Methods In this HIPAA-compliant institutional review board–approved retrospective study with waiver of informed consent, 247 patients (196 men, 51 women; mean age, 60 years ± 11 [standard deviation]) with liver cirrhosis who underwent evaluation for HCC with MR imaging were identified via database search. Three radiologists independently reviewed images and identified number and size of HCC based on criteria within either the prior or revised policy. Based on these interpretations, priority for liver transplantation for each patient was determined with prior and revised transplantation allocation criteria. HCC detection was compared between sessions by using McNemar tests, and interreader agreement for detection of at least one HCC was assessed by using κ coefficients. Results All three readers detected significantly more 1–2-cm HCCs with the revised policy (readers detected 22, eight, and 20 1–2-cm HCCs) versus the prior policy (no reader detected 1–2-cm HCCs) (P ≤ .031). All readers detected significantly fewer 2–5-cm HCCs with the revised policy (readers detected eight, 13, and 14 2–5-cm HCCs) versus the prior policy (readers detected 24, 21, and 24 2–5-cm HCCs) (P ≤ .027). For all readers, fewer patients met criteria for increased transplantation priority with the revised versus the prior policy (number of patients who received increased priority for the three readers were 4.9% [12 of 247] vs 9.3% [23 of 247]; 5.7% [14 of 247] vs 8.1% [20 of 247]; and 6.9% [17 of 247] vs 8.9% [22 of 247]). Interreader agreement was substantial for the prior policy (κ = 0.607) and almost perfect for the revised policy (κ = 0.813). Conclusion Among cirrhotic patients who underwent evaluation for HCC with MR imaging, the revised OPTN/UNOS policy led to increased detection of 1–2-cm HCCs, decreased detection of 2–5-cm HCCs, and fewer patients who met criteria for increased transplant priority. © RSNA, 2014