Identification of responders to sorafenib in hepatocellular carcinoma: Is tumour volume measurement the way forward?

Background and aims: Early assessment of hepatocellular carcinoma (HCC) response during sorafenib (SO) treatment is challenging, since tumour necrosis can be inhomogeneous as far as extension and radiological appearance. We retrospectively evaluated prognostic value of different imaging criteria, such as RECIST (Response Evaluation Criteria in Solid Tumours) 1.1, EASL (European Association for the Study of the Liver), modified RECIST (mRECIST), tumour density and volume variations, in the early follow-up of SO treatment. Methods: The study included 22 patients (18 male, mean age 68 years). Two independent radiologists reviewed baseline and 2-months follow-up computed tomography (CT) images to assess response according to RECIST 1.1, mRECIST, EASL, Choi's criteria (decreased tumour density ≥ 15%) and arterial-enhancing tumour volume ratio. Alfa-fetoprotein (AFP) variations were expressed as AFP ratio. This study was exempt from Institutional Review Board (IRB) approval after institutional IRB review. Results: Response criteria and volume measurements were reproducible (k > 0.80). The overall disease control rate was 40.9% by EASL and mRECIST and 27.3% by RECIST 1.1; a ≥15% decrease in tumour density was observed in 9 patients (40.9%). Mean volume ratio was 1.73 ± 2.12; mean AFP ratio was 14 ± 37. One-year overall survival rate was 65.9%. Volume ratio resulted to be the only prognostic factor for survival, with 1-year cumulative survival rates of 90% for volume ratio ≤ 1.1 and 45.4% for volume ratio > 1.1 (P = 0.04). Conclusion: Tumour volume measurements are reproducible and should be considered as an alternative to RECIST, mRECIST and/or EASL since they may provide an early prognostic marker of response in HCC patients treated with SO.