Usefulness of dose intensity/body surface area ratio (DI/BSA ratio; DBR) rather than relative dose intensity in the lenvatinib treatment for hepatocellular carcinoma

Abstract

Relative dose intensity (RDI) is the ratio between the delivered dose intensity and the standard dose. Maintaining high RDI has been shown to improve clinical outcomes in various cancers. The dose of lenvatinib was determined according to patient's weight (12 mg/day for ≥60 kg or 8 mg/day for <60 kg); therefore, RDI could not reflect the actual treatment intensity in some cases. Here, we evaluated the utility of dose intensity/body surface area ratio (DBR). The difference in PFS between patients with high RDI (≥0.67) and low RDI (p = 0.0534) was not significant, whereas patients with high DBR (≥240) showed significantly better PFS than those with low DBR (p < 0.0001). DBR may be more appropriately used in assessing the lenvatinib treatment intensity as compared with RDI.