Purpose: Superselective conventional transarterial chemoembolization (ss‑cTACE) guided by angiography–multidetector CT (AMDCT) improves feeder detection but can broaden the treated territory and compromise hepatic reserve. We asked whether restricting the embolized area to < 1 Couinaud sector‑equivalent is associated with better prognosis in treatment‑naïve hepatocellular carcinoma (HCC). Our primary estimand was the covariate‑adjusted hazard ratio (HR) comparing extended (≥ 1 sector‑equivalent) vs limited (< 1 sector‑equivalent) embolization. Patients and Methods: We conducted a single‑center retrospective cohort including 195 consecutive patients with newly diagnosed HCC who underwent initial ss‑cTACE/AMDCT (2010‑10‑01 to 2023‑08‑31; median age 75 years). Post‑procedural imaging classified patients as Group L (< 1 sector‑equivalent; n=136) or Group E (≥ 1; n=59). Endpoints were progression‑free survival (PFS) and overall survival (OS); liver‑related death was modeled with cause‑specific hazards. Multivariable Cox models were prespecified as primary, with propensity‑score overlap weighting as a complementary sensitivity analysis; short‑term hepatic safety was assessed by post‑TACE ALBI within 1 month. Results: Compared with Group L, Group E showed shorter PFS (median 7 vs 12 months; aHR 1.7, 95% CI 1.1– 2.5; p =.01) and OS (median 21 vs 33 months; aHR 2.1, 95% CI 1.2– 3.5; p =.003). Short‑term hepatic safety did not differ: the post‑TACE ALBI score assessed within 1 month was similar between groups (− 2.1 ± 0.4 vs − 2.0 ± 0.4; p =.16). In Group L, liver‑related survival exceeded OS (113 vs 57 months; p =.01). Adjusted analyses confirmed embolization extent as an independent prognostic factor beyond stage, tumor burden, location, and liver function (PFS aHR 1.7; OS aHR 2.1). Among Group L decedents, HBV/HCV was independently associated with liver‑related death (OR 6.9, 95% CI 1.8– 34; p =0.009). Conclusion: During initial ss‑cTACE/AMDCT, restricting embolization to < 1 sector‑equivalent was associated with longer PFS/OS and fewer liver‑related deaths, supporting treatment planning that minimizes ischemic parenchymal injury, particularly in older or vulnerable patients. Plain Language Summary: Transarterial chemoembolization (TACE) treats liver cancer (HCC) by blocking blood flow to the tumor. Using a combined angiography–CT system (AMDCT), doctors can find very small feeding arteries and target them precisely. However, when many tiny branches are involved, the treated area can unintentionally become wide and may harm healthy liver tissue. We reviewed 195 patients who received their first TACE at our hospital. After treatment, we grouped patients by how much of the liver was embolized: less than one anatomical sector (limited) or one sector or more (extended). Patients in the limited group lived longer without needing further treatment and lived longer overall than those in the extended group. They also had fewer deaths caused by liver problems, suggesting that preserving liver reserve is crucial for long‑term outcomes. These findings were confirmed using additional statistical checks designed to make fairer comparisons between the two groups. Importantly, short‑term liver function measured about a month after TACE was not worse in the limited group. What does this mean? For many patients—especially older adults or those with fragile liver function—planning TACE to keep the treated area as small as reasonably possible may lower the chance of liver‑related complications and help patients live longer. These results support careful, territory‑sparing strategies when technically feasible. Keywords: hepatocellular carcinoma, transarterial chemoembolization, angiography–MDCT, embolization extent, survival, propensity score, cause-specific hazard
Okumura et al. (Sun,) studied this question.