Prospective Validation of An Inpatient Metastatic Spine Neoplasm Score To Assess the Optimal Radiation Therapy Intervention Modality.

Objectives: Metastatic spine disease is typically treated with conventional external beam radiation therapy (EBRT) or stereotactic body radiation therapy (SBRT). Recently, an inpatient metastatic spine score evaluated retrospectively produced promising results in selecting patients with prognoses favorable enough to benefit from the durability advantages of SBRT over EBRT, with scores of 0 to 3 warranting recommendation of SBRT over EBRT compared with scores of 4 to 7 yielding median survival <90 days. This study represents a prospective evaluation of this algorithm to further assess its potential utility.

Methods: From July to November 2023, 11 spine metastases referred for inpatient radiation oncology consultation were prospectively assessed according to the inpatient metastatic spine score: scores of 0 to 3 were recommended for SBRT, and 4 to 7 for EBRT or no radiation therapy. The timeframe from consultation to death/hospice was correlated with the cumulative score.

Results: The median age was 68.5 years. Patients with a score of 0 to 3 (n=5) had a median survival of 278 days, compared with scores of 4 to 7 (n=6) having a median survival of 37.5 days; this difference was statistically significant (P=0.0146).

Conclusions: Prospective validation of the inpatient metastatic spine score reveals the prognosis of patients with scores of 4 to 7 have median survival too brief to benefit from the durability advantages of SBRT over EBRT, while scores of 0 to 3 have a prognosis long enough to benefit from SBRT. These results concur with previous retrospective evaluation, and indicate that the inpatient metastatic spine score is a reliable tool for determining which inpatients with spine metastases are appropriate for SBRT over EBRT.