Improving laser-induced thermotherapy of liver metastases – Effects of arterial microembolization and complete blood flow occlusion

Introduction A prerequisite for an oncologically curative application of laser-induced thermotherapy (LITT) of liver metastases is complete tumor destruction. This increased effectiveness was achieved experimentally by combining LITT with interrupted hepatic perfusion. The aim of this study was to evaluate whether an interventional selective arterial microembolization might be as effective as complete blood flow occlusion using an open Pringleʹs maneuver. Patients and methods We included patients with unresectable colorectal liver metastases. LITT was performed without interrupted hepatic perfusion (control group) compared to LITT in combination with interrupted perfusion either by embolization of intraarterial degradable starch microspheres (DSM) (percutaneous access) or by complete hepatic inflow occlusion (Pringleʹs maneuver; open access). Online monitoring was performed using intraoperative ultrasound or MRI. Volumetric techniques were used to assess metastases and postinterventional lesions. Results Fifty-six patients with 104 metastases (control group (25), DSM (37), and Pringle (42)) were treated. The preinterventional tumor volumes were significantly smaller than the postinterventional lesion volumes (control group: 9.8 vs. 25.3 cm3; DSM: 9.5 vs. 65.4 cm3; Pringle: 12.9 vs. 76.5 cm3). The morbidity rate was 21.4% without treatment-related mortalities. After 6 months follow-up, tumor recurrence was diagnosed in 6 patients (control group (4), LITT with DSM (1), and Pringle (1)). Conclusions Combinig LITT with blood flow occlusion leads to a significant increase in lesion size. The application of DSM offers a safe and effective alternative to the open access with Pringleʹs maneuver. Compared to LITT-monotherapy, this modality achieves significantly larger thermal lesions with the need of fewer applications.