Introduction: Open surgery followed by radiation is standard of care for unstable spine metastasis. Post-radiation vertebral-compression-fractures (VCF) range from 11-39%. As radiation is palliative due to systemic tumor burden, pain and quality of life improvement is paramount. Kyphoplasty intraoperative radiation therapy (Kypho-iORT) is a minimally invasive procedure to radiate metastasis from within vertebral bodies, preventing VCF while providing immediate pain relief in potentially unstable spines.
Methods: This is a prospective phase I/II clinical trial to assess safety and efficacy of Kypho-iORT for potentially unstable spinal metastasis in improving pain and functional status and maintaining local control. Pain scores were assessed with the numerical rating pain scale (NRPS), functional status with brief pain inventory (BPI), local control and VCF with CT/MRI.
Patients with symptomatic metastasis underwent intraoperative electron-accelerated radiation followed by kyphoplasty. Tumors were limited to vertebral body with SINS scores 7-12. Intraoperative CT was used to delineate tumor volume, confirm transpedicular access to tumor, and conform 10Gy from source to tumor periphery.
Results: 13 levels in 9 patients were treated. Mean age 51.3years. Mean SINS score 9.18±1.99. No patients experience neurological deterioration. Mean local-progression-free-survival was 8.3months. After 3months, one patient with metastatic colon adenocarcinoma cancer suffered local progression. Mean VCF-free-survival 8.4months, with asymptomatic VCF in 1 patient at 6 months.
NPRS scores decreased from preoperative (6.55±2.54) to 1week (3.00±2.57; p=0.002), 3months (3.25±2.87; p=0.007), 6months (2.00±2.12; p=0.002) and trend toward improvement at 9months (2.00±1.73; p=0.083). Functional status improved with reduced mean BPI at 3months (54.90±9.29 vs 37.6±19.98; p=0.037), 6months (32.0±18.49; p=0.073), and 9months (25.67±5.77; p=0.034). Narcotic reduced in 4/7 patients. 3/7 were medication free.
Conclusions: Kypho-IORT is a safe option for potentially unstable spinal metastases. Pain and function significantly improve, enhancing quality of life. Local control and reduction in VCF can be obtained. Long-term follow-up is necessary to further evaluate efficacy.
Patient Care: 1. Patients with metastatic disease may be candidates for MIS surgery for administration of radiation and kyphoplasty in one setting with immediate sustained improvement in pain and functional status.
Learning Objectives: 1. Identify alternative treatment for potentially unstable spinal metastatic lesions.
2. Understand need for quality of life improve in patients with metastatic disease.