Modified Radiation Lobectomy Strategy of Radioembolization for Right-Sided Unresectable Primary Liver Tumors

Purpose To assess the safety and effectiveness of using modified radiation lobectomy (mRL) to treat primary hepatic tumors located in the right hepatic lobe (segments V-VIII) and determine future liver remnant (FLR) hypertrophy. Methods A retrospective review was performed at a single institution to include 19 consecutive patients (7 Female, 12 Male) who underwent single-session mRL for right sided primary hepatic tumors: 15 received segmentectomy plus lobectomy (segmental dose >190 Gy and lobar dose >80 Gy); 4 were treated with the double-segmental approach (dominant segments >190 Gy and non-dominant segments > 80 Gy). Treated tumors included 13 hepatocellular carcinoma (HCC), 4 cholangiocarcinoma (CCA), and 2 mixed-type HCC-CCA with a median dominant tumor size of 5.3 cm (Interquartile range [IQR]: 3.7-7.3cm). FLR of the left hepatic lobe was measured at baseline, T1 (4-8 weeks), T2 (2-4 months), T3 (4-6 months), and T4 (9-12 months). Results Objective tumor response and tumor control were achieved in 17/19 (89.5%) and 18/19 (94.7%) patients, respectively. FLR hypertrophy was observed at T1 (median 47.8%, p=0.0245), T2 (median 48.4%, p=0.0120), T3 (median 50.4%, p=0.0147), and T4 (median 59.1%, p=0.00023). Non-cirrhotic patients demonstrated greater hypertrophy by 6-month (median 55.8% vs 47.2%, p=0.0310). One patient developed a grade 3 adverse event (ascites requiring paracentesis) at 1-month follow-up. Grade 2 or above serum toxicities are associated with worse baseline Child-Pugh Score, serum albumin, and total bilirubin (p<0.05). Among 7 patients who underwent neoadjuvant mRL, two underwent resection and one received liver transplant. Conclusion mRL appears safe and effective for treatment of right-sided primary hepatic tumors with the benefit of promoting FLR hypertrophy.