Combined 18F-FDG and 11C-acetate positron emission tomography/computed tomography in staging and treatment decision in patients with hepatocellular carcinoma: A cost-effectiveness analysis.

e16176 Background: Dual-tracer positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose and 11C-acetate is increasingly used in the management of hepatocellular carcinoma (HCC). However, considering the high cost of dual-tracer PET/CT, there is a need to assess its value by considering both the efficacy and cost. Methods: In this retrospective cohort study, 223 dual-tracer PET/CT scans were performed in 206 patients between 2014 and 2020 for tumor staging for radiologically or histologically confirmed HCC. New lesion detection rate, changes in the Barcelona Clinic Liver Cancer (BCLC) classification, and changes in treatment allocation based on dual-tracer PET/CT were evaluated. Validation was performed on a cohort of staging patients from another institution (n = 48). A cost-benefit analysis model was built for the incurred costs and the impact of dual-tracer PET/CT findings on treatment strategy over conventional imaging was studied. Results: Of the 223 patients that underwent dual-tracer PET/CT for staging, new lesions were detected in 33 (14.8%) patients, resulting in BCLC upstaging in 26 (11.6%) and treatment modification in 16 (7.2%) cases. The external staging cohort showed similar findings where dual-tracer PET/CT resulted in 12.5% (6/48) BCLC upstaging and 10.4% (5/48) treatment modifications (concordance-index: 0.85; 95% CI: 0.82-0.88). In subgroup analysis of 200 patients performed for pre-treatment metastatic screening, dual-tracer PET/CT detected extra-hepatic metastasis in 11, 10, and 16 patients, respectively, and led to treatment modifications in all of these patients. Sixteen locoregional therapies (8%) were avoided (8 resections, 3 transplantations, and 5 TACEs), with an estimated cost saving of US$161,665 (US$808 / patient) from the use of dual-tracer PET/CT. Sensitivity analyses suggested that dual-tracer PET/CT is consistently more cost-saving than conventional imaging, irrespective of the changes in the cost of imaging, procedures, and the duration of hospital stay (range: US$112,945-210,385). The cost of PET/CT had the greatest influence on the cost savings. Conclusions: Comparing to conventional imaging, dual-tracer PET/CT improves tumor staging, alters treatment allocation and is cost-saving in patients undergoing pre-treatment metastatic screening. Our results demonstrated that the use of dual-tracer PET/CT provides additional value and improves patient care.