EXTH-03. A Novel Porcine Model of Laser Interstitial Thermal Therapy for Metastatic Epidural Spinal Cord Compression

INTRODUCTION Spinal metastases from prevalent cancers—such as breast, prostate, and lung—affect over 100,000 patients annually. Metastatic epidural spinal cord compression (MESCC) is a severe complication that can lead to significant neurological deficits and requires urgent intervention. Although stereotactic radiation therapy effectively controls spinal metastases, MESCC often necessitates “separation surgery” to physically distance the tumor from the spinal cord to prevent radiation-induced injury. However, separation surgery is invasive, prolongs hospitalization, interrupts systemic therapy, and delays radiation. Laser Interstitial Thermal Therapy (LITT) presents a minimally invasive alternative, but its clinical adoption is limited by challenges in MRI thermography and precise laser fiber placement in the spine. Here, we introduce a novel porcine model of MESCC to address these limitations. METHODS We established a porcine xenograft spine tumor model by implanting human breast cancer (HCC70) or osteosarcoma (143B) cells into the vertebral bodies of immunosuppressed Yucatan mini pigs. Tumor progression was monitored using serial CT and MRI. For LITT, commercial laser fibers were percutaneously placed under image guidance. To improve real-time MRI thermography during ablation, we developed motion compensation techniques that eliminate the need for breath holding, and we compared MRI-derived tissue damage estimates with histopathological findings. RESULTS The model demonstrated consistent, radiographically evident tumor growth. Breath-holding during thermography introduced significant noise and caused unreliable tissue damage estimates, whereas multi-baseline and reference-less algorithms substantially reduced motion artifacts. Discrepancies between MRI damage estimates and histopathology highlight the necessity for further validation of MRI thermography in the spine. DISCUSSION LITT is a promising, minimally invasive alternative to separation surgery for MESCC. Its successful clinical translation depends on the development of robust, motion-compensated MRI thermography algorithms and the absolute validation of MRI-based damage assessments. Our porcine model offers an ideal platform for overcoming these challenges.