The Taipei Integrated Score System, introduced by Hsu et al. in 2010, stems from a study of 2030 HCC patients undergoing diverse treatments in Taiwan. It incorporates total tumor volume (TTV) as a tumor burden surrogate, combined with cirrhosis-related models (Child-Pugh grade, MELD, MELDNa, MELD-Na) to form the TTV-based staging system. TTV is categorized into four groups (< 50 cm3, 50-250 cm3, 250-500 cm3, > 500 cm3), assigned single-digit values (0-3), yielding 12 models. Patients are categorized into seven groups (0-6). TTV-Child-Pugh grade-AFP model exhibits optimal prognostic value, surpassing current staging systems (CLIP, BCLC, JIS, Tokyo) and excelling in non-curative treatment cases.

Although the TTV-based system offers utility and reliability from a comprehensive cohort, concerns arise. TTV estimation assumes spherical tumors, potentially leading to inaccuracies with infiltrative or numerous tumors. Also, this system is built on a cohort with predominant HBV infection (55%), necessitating external validation in Western populations.