Precision transarterial chemoembolization in hepatocellular carcinoma: patient selection, standardized techniques, and quantitative evaluation.

Transarterial chemoembolization (TACE) plays a critical role in the treatment of hepatocellular carcinoma (HCC), yet variability in its performance leads to inconsistent prognostic outcomes, with objective response rates (ORRs) ranging from below 10% to over 60% for intermediate HCC. Published evidence and recommendations emphasize that TACE should be executed with precise targeting and accessibility to superselective catheterization. To enhance quality control and standardize TACE procedures, the concept of "precision TACE" is introduced by an international expert panel of International Society of Multidisciplinary Interventional Oncology (ISMIO), emphasizing the inclusion of standardized angiography, superselective catheterization and embolization, appropriate selection of embolic agents, determination of optimal embolization endpoints, and evaluation for efficacy immediately post-TACE. Precision TACE is divided into superior precision TACE (SP-TACE) and moderate precision TACE (MP-TACE). SP-TACE aims at achieving complete response (CR) or close to CR for all treated intrahepatic lesions in one session, while minimizing damage to normal liver tissue as much as possible. For SP-TACE, ideal candidates are intermediate HCCs with moderate intrahepatic tumor burden (maximum diameters of lesions no more than 5 cm, possibly up to 7 cm, with less than 5 intrahepatic lesions) and early HCCs who are unable or unwilling to receive curative approaches. MP-TACE aims at achieving partial response (PR) or stable disease (SD) for treated intrahepatic lesions with one or repeated sessions of TACE. For MP-TACE, ideal candidates are intermediate HCCs with high intrahepatic tumor burden and locally-advanced HCCs (with vascular invasion). Besides, precision TACE combined with other therapies such as ablation, systemic therapies, and hepatic resection, is discussed. Lastly, a scoring system for quantifying the precision of TACE is proposed to evaluate its effectiveness.