To describe the outcome of radiation lobectomy (RL) after double vein embolization (portal vein embolization + hepatic vein embolization) for patients with insufficient future liver remnant growth.

All patients with insufficient FLR function (as determined by hepatobiliary scintigraphy (HIDA); < 2.7%/min/m2) after double vein embolization who underwent RL between 2020 and 2023 were selected. Follow-up consisted of toxicity graded according to the Common Terminology Criteria for Adverse Events v. 5.0 criteria, HIDA and computed tomography imaging at 1–2-month intervals to assess treatment effect and resectability. Postoperative complications were graded according to the Clavien–Dindo system.

Five patients with colorectal liver metastases were selected. After RL, 4/5 patients had sufficient FLR function. Overall, the median volumetric and functional increase of the FLR was 47.5% (range 5.8–102.8%) and 66.7% (range 0–233.3%), respectively, and within a median of 81 days. No severe toxicities were reported after adjunct RL. Two patients did not undergo surgery due to disease progression. Three patients underwent surgery. The postoperative stay was complicated by persistent bile leakage in one patient and respiratory insufficiency in another. There was no 90-day mortality.

RL was safely employed in adjunct to double vein embolization to induce a further increase in the FLR volume and function.