Laser Thermal Ablation for Metastases Failing Radiosurgery: A Multicentered Retrospective Study

Radiosurgical failure following stereotactic radiosurgery for brain metastases can be attributed to tumor regrowth or radiation necrosis. MRI-guided laser thermal ablation (LTA) therapy has emerged as an option for treatment; however, previous literature demonstrates variable results across centers.

To assess the outcomes of LTA in the treatment of metastases failing radiosurgery across multiple centers and to determine if any treatment factors are predictive of outcome.

Clinical data for 30 patients across 4 centers were retrospectively reviewed. Patients were included if they received LTA therapy following radiosurgical failure due to radiation necrosis or tumor regrowth. Demographics, surgical data, and follow-up imaging and clinical information were collected. Linear regression analyses were performed to determine treatment factors that were associated with post-LTA outcome.

The large majority of patients responded favorably to LTA treatment with low complication rates (23%), short length of stay (53% ≤ 2 d) and reductions in perilesional edema (63%). A total of 73.3% of patients stopped steroids and 48% saw improvement of their preoperative symptoms. Patients with better pre-LTA Karnofsky Performance Status had better survival. Patients who had lesions with more perilesional T2 change post-LTA had a better chance of weaning off steroids and obtaining symptomatic relief.

MRI-guided laser thermal ablation therapy serves as a viable alternative to traditional treatment options for metastatic brain lesions failing radiosurgery. Although this study is limited by size and is retrospective, LTA therapy may result in symptomatic improvement and a more prominent reduction in fluid-attenuated inversion-recovery signal for larger lesions.