[F]fluorodeoxyglucose and [F]fluorocholine PET-CT for staging optimisation and treatment modification in hepatocellular carcinoma (PET-HCC01): a prospective multicentre study.

Background: The role of PET-CT with [F]fluorodeoxyglucose ([F]FDG) and [F]fluorocholine ([F]FCH) in staging hepatocellular carcinoma and treatment decisions has, to our knowledge, never been prospectively assessed.

Methods: We conducted a multicentre prospective study (PET-HCC01) in nine hospitals in France, including patients aged 18 years or older with a first diagnosis of hepatocellular carcinoma classified as Barcelona Clinic Liver Cancer (BCLC) classification A to C (without metastasis). At study inclusion, patients underwent contrast-enhanced liver MRI and liver, chest, and pelvis CT scans. Patients subsequently underwent [F]FCH and [F]FDG PET-CT. A first tumour staging and treatment decision was recorded by the multidisciplinary tumour board at each centre using morphological imaging, blind to the results of the PET-CTs. After the results of the PET-CTs were revealed, a second tumour staging and treatment decision was recorded. The primary endpoint was the proportion of patients whose treatment was modified by PET-CTs. Analyses were done in the intention-to-image population, consisting of all patients who had undergone at least one PET-CT and were discussed by the multidisciplinary tumour board. This study was registered with ClinicalTrials.gov, NCT04391348.

Findings: Between July 20, 2020, and April 27, 2023, 230 patients were enrolled. Among the 215 patients included in the intention-to-image population, the median age was 66·0 years (IQR 60·0-71·5), 193 (90%) were male, and 155 (73%) had cirrhosis. Hepatocellular carcinoma was classified as BCLC stage A in 140 (65%) patients, B in 48 (22%), and C without metastasis in 27 (13%) on the basis of morphological imaging. Potential new lesions were identified in 19 (9%) patients by PET-CT (eight by both tracers, six by [F]FCH only, and five by [F]FDG only) and in six of these patients, follow-up confirmed the diagnosis of hepatocellular carcinoma (one lesion in the adrenal gland, two in bones, two in the lymph node, and one intrahepatic). PET-CT modified BCLC stage in ten patients: disease stage for two patients moved from BCLC A to B, from BCLC A to C for two patients, from BCLC B to C for two patients, and from BCLC C without metastasis to BCLC C with metastasis for four patients. Planned treatment was modified for four patients (2% [95% CI 1-5]), below the prespecified threshold of clinical significance (10%).

Interpretation: [F]FDG and [F]FCH-PET-CTs should not be systematically performed for staging a first diagnosis of hepatocellular carcinoma, as they modified treatment decisions only in a minority of patients.

Funding: Programme Hospitalier de Recherche Clinique Inter-regional-PHRC-I2018 (Ministère de la Santé).