Radiofrequency ablation for hepatocellular carcinoma: Clinical value of ultrasound–ultrasound overlay fusion for optimal ablation and local controllability. Issue 1 (9th August 2019) - Minami, Yasunori
Abstract : Aim: To retrospectively investigate the potential benefit of ultrasound–ultrasound (US‐US) overlay fusion guidance for local controllability of radiofrequency ablation (RFA) in the treatment of hepatocellular carcinoma (HCC). Methods: Patients ( n = 101) with 121 HCCs (mean ± SD, 1.8 ± 0.7 cm) who underwent RFA guided by US‐US overlay fusion were included in the retrospective study. By overlaying pre/postoperative US, the tumor image could be projected onto the ablative hyperechoic zone. The ablative margin could thereby be evaluated three‐dimensionally during the RFA procedure. As a control group, all 325 patients with 453 HCCs who underwent conventional RFA during the same study period were selected. Results: The total number of RF needle insertions per tumor for ablation was significantly more in the US overlay fusion group (mean 1.9 vs. 1.2; P < 0.01). The technical success rates of ablation after a single session were 100% (101/101) and 96.6% (314/325) for the US overlay fusion group and the control group, respectively. For early assessment of RFA response, 5‐mm safety margins were achieved in 89.3% (108/121) and 47.0% (213/453) of nodules in the US overlay fusion group and the control group, respectively ( P < 0.01). During the follow‐up period (median 19 months), the 2‐year local tumor progression rates were 0.8% (1/121) and 6.0% (27/453) in the US overlay fusion group and the control group, respectively ( P = 0.022, log–rank test). Conclusions: US‐US overlay fusion guidance can be highly effective for safety margin achievement in RFA for HCC, providing a lower risk of local tumor progression.