PACM-06 LASER INTERSTITIAL THERMAL THERAPY IN A PORCINE SPINE TUMOR MODEL DEMONSTRATES A PROMISING ALTERNATIVE TO SEPARATION SURGERY FOR METASTATIC EPIDURAL SPINAL CORD COMPRESSION
Armin Tavakkoli, Beverly Petusseau, David Hunter, Linton EvansAbstract
Introduction
Spinal metastases from breast, prostate, and lung cacners 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 five (n = 5) immunosuppressed Yucatan mini pigs. Tumor progression was monitored using serial CT and MRI. For LITT, commercial laser fibers were percutaneously placed, and image-guided methods for accurate placement and securement using existing spine surgery tools were compared. 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. The refined fiber placement workflow showed excellent targeting accuracy. As expected, breathing during ablation introduced significant thermography noise and caused unreliable tissue damage estimates, but multi-phase reference and referenceless thermography algorithms substantially reduced these motion artifacts. Discrepancies between MRI damage estimates and histopathology highlight the necessity for further validation of MRI thermography in the spine.
Conclusions
LITT is a promising, minimally invasive alternative to separation surgery for MESCC, and our porcine model offers an ideal platform for overcoming challenges associated with its clinical adoption.