In:
Journal of Neurosurgery: Spine, Journal of Neurosurgery Publishing Group (JNSPG), Vol. 34, No. 2 ( 2021-02), p. 267-276
Abstract:
This study evaluated a large cohort of patients treated with stereotactic body radiation therapy for spinal metastases and investigated predictive factors for local control, local progression-free survival (LPFS), overall survival, and pain response between the different spinal regions. METHODS The study was undertaken via retrospective review at a single institution. Patients with a tumor metastatic to the spine were included, while patients with benign tumors or primary spinal cord cancers were excluded. Statistical analysis involved univariate analysis, Cox proportional hazards analysis, the Kaplan-Meier method, and machine learning techniques (decision-tree analysis). RESULTS A total of 165 patients with 190 distinct lesions met all inclusion criteria for the study. Lesions were distributed throughout the cervical (19%), thoracic (43%), lumbar (19%), and sacral (18%) spines. The most common treatment regimen was 24 Gy in 3 fractions (44%). Via the Kaplan-Meier method, the 24-month local control was 80%. Sacral spine lesions demonstrated decreased local control (p = 0.01) and LPFS (p 〈 0.005) compared with those of the thoracolumbar spine. The cervical spine cases had improved local control (p 〈 0.005) and LPFS (p 〈 0.005) compared with the sacral spine and trended toward improvement relative to the thoracolumbar spine. The 36-month local control rates for cervical, thoracolumbar, and sacral tumors were 86%, 73%, and 44%, respectively. Comparably, the 36-month LPFS rates for cervical, thoracolumbar, and sacral tumors were 85%, 67%, and 35%, respectively. A planning target volume (PTV) 〉 50 cm 3 was also predictive of local failure (p = 0.04). Fewer cervical spine cases had disease with PTV 〉 50 cm 3 than the thoracolumbar (p = 5.87 × 10 −8 ) and sacral (p = 3.9 × 10 −3 ) cases. Using decision-tree analysis, the highest-fidelity models for predicting pain-free status and local failure demonstrated the first splits as being cervical and sacral location, respectively. CONCLUSIONS This study presents a novel risk stratification for local failure and LPFS by spinal region. Patients with metastases to the sacral spine may have decreased local control due to increased PTV, especially with a PTV of 〉 50 cm 3 . Multidisciplinary care should be emphasized in these patients, and both surgical intervention and radiotherapy should be strongly considered.
Type of Medium:
Online Resource
ISSN:
1547-5654
DOI:
10.3171/2020.6.SPINE20861
Language:
Unknown
Publisher:
Journal of Neurosurgery Publishing Group (JNSPG)
Publication Date:
2021
Permalink