[¹⁸F]fluorodeoxyglucose and [¹⁸F]fluorocholine PET-CT for staging optimisation and treatment modification in...

The role of PET-CT with [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) and [¹⁸F]fluorocholine ([¹⁸F]FCH) in staging hepatocellular carcinoma and treatment decisions has, to our knowledge, never been prospectively assessed.

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 [¹⁸F]FCH and [¹⁸F]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.

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 [¹⁸F]FCH only, and five by [¹⁸F]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%).

[¹⁸F]FDG and [¹⁸F]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.

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