Primary Stereotactic Body Radiotherapy for Spinal Bone Metastases From Lung Adenocarcinoma

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Spinal bone metastases (SBM) from lung adenocarcinoma (ADC) present significant treatment challenges.
• Stereotactic body radiotherapy (SBRT) is an emerging primary treatment modality for SBM.
• Predictive factors for treatment outcomes in SBM require further investigation.

Purpose of the Study:

• To evaluate the efficacy of primary SBRT using the CyberKnife System for lung ADC-originating SBM.
• To identify clinical and genetic factors influencing local control (LC) and local progression (LP) after SBRT.
• To correlate survival outcomes with treatment response.

Main Methods:

• Retrospective analysis of 99 adult patients with lung ADC and SBM treated with primary SBRT (CyberKnife) between 2012 and 2023.
• Assessment of local control (LC) rates, local progression (LP) occurrence, and survival.
• Evaluation of the revised Tokuhashi score (rTS), Spinal Instability Neoplastic Score (SINS), osteolytic destruction, pain, PD-L1 expression, and EGFR mutations as predictive factors.

Main Results:

• A 90.7% one-year LC rate was observed for SBM from lung ADC treated with primary SBRT.
• Median time to local progression was 10.0 months; poor prognosis (rTS) and spinal instability (SINS) were associated with increased LP.
• Osteolytic bone destructions and pain significantly correlated with LP; genetic factors (PD-L1, EGFR) did not significantly impact LC.

Conclusions:

• Primary SBRT, particularly with the CyberKnife System, demonstrates high efficacy in achieving local control for lung ADC SBM.
• Clinical factors like spinal instability and osteolytic lesions are crucial predictors of treatment failure.
• Achieving local control with SBRT is associated with significantly improved patient survival.