Y. R. Wuu1,2, R. Chan3,4, H. Zhang3,4, B. Gui1,2, M. Rob5, J. Antone3,4, A. Wint3,4, L. Lo4,6, D. M. Sciubba4,6, and M. Ghaly1,2; 1Northwell, Lake Success, NY, 2Department of Radiation Medicine, Northwell, Lake Success, NY, 3Northwell, Department of Radiation Medicine, Lake Success, NY, 4Northwell, New Hyde Park, NY, 5NYIT College of Osteopathic Medicine, Glen Cove, NY, 6Northwell, Department of Neurosurgery, New Hyde Park, NY
Purpose/Objective(s):High-grade epidural spinal cord compression (ESCC) results in significant neurological deficits, compromising quality of life. There are two surgical approaches prior to post-operative stereotactic body radiotherapy (SBRT): Separation surgery (SS) vs. Corpectomy with Subtotal Tumor Resection (C+STR). Both approaches are equally effective in symptomatic management; however, C+STR allows for proper gross tumor separation, which allows delivery of higher therapeutic radiation doses while respecting spinal cord tolerance and provides durable long-term control, regardless of tumor histology. This study aimed to compare dosimetry data and outcomes between SS and C+STR for patients with high-grade ESCC. Materials/
Methods: Patients with high-grade ESCC spine metastasis who underwent surgical decompression and adjuvant SBRT were reviewed between 2012 to 2022. Baseline characteristics (i.e., age, gender, hospital length stay, histology) and dosimetry data were collected. Conformity index (CI) was calculated based on the Paddick CI equation. The primary endpoint was time to local progression based on post-treatment MRI. Patients who received prior radiation to the same vertebral level were excluded. T-test and Fisher’s exact test were used to evaluate the baseline characteristics and dosimetric data between the two groups. Kaplan Meier analysis was used to evaluate local control (LC). All analyses were performed in SAS OnDemand for Academics. Results: A total of 25 patients met the inclusion criteria—15 managed with SS and SBRT (S+SBRT); 10 had Corpectomy/STR and SBRT (C+SBRT). Both groups showed significant postoperative improvements in neurological status with a mean hospital stay of 10 vs 12 days (p = 0.31) in the (S+SBRT) and (C+SBRT) cohorts, respectively. Baseline characteristics were matched between groups. Mean Gross Tumor Volume (mGTV) coverage with higher radiation doses were significantly higher in (C+SBRT) vs. (S+SBRT): mGTV V100%, mGTV V95%, and mGTV V90% were 90% vs. 71% (p = 0.038), 94% vs. 77% (p = 0.046), and 96% vs. 80.0% (p = 0.044), respectively. CI was also statistically significantly higher in the (C+SBRT) group (0.97 vs. 0.89, p = 0.043). Mean follow-up time for (S+SBRT) and (C+SBRT) were 27.8 and 23.8 months, respectively. The (C+SBRT) cohort had a positive trend toward increased durable long-term control vs (S+SBRT), 54 vs. 10 months (p = 0.09). 6/15 patients in the (S+SBRT) cohort had local recurrence vs. 2/10 in the (C+SBRT) cohort. There was no difference in overall survival. Conclusion: This dosimetric analysis suggests complete epidural decompression with corpectomy in good performance status patients with high-grade ESCC may improve LC. This approach allows for optimum tumor coverage with higher radiation doses, which is important for long-term outcomes. Further studies are necessary to confirm these findings.
