Spine Stereotactic Radiosurgery Provides Pain Relief and Durable Local Tumor Control for Lung Cancer Spine Metastases

Introduction: Lung cancer is the most common primary malignancy to metastasize to the spine, frequently leading to intractable pain, neurological deficit, and mechanical instability. This single-institution study is one of the largest to examine the safety, efficacy, and long-term outcomes following stereotactic radiosurgery (SRS) for lung cancer spinal metastases.

Methods: A prospectively collected database of patients with lung cancer spinal metastases treated at a single institution from 2003-2023 was analyzed. The primary outcome was local control (LC). Secondary outcomes included pain improvement, overall survival (OS), and adverse radiation effects (AREs). Cox proportional hazard analyses were performed to identify relationships between relevant clinical parameters and outcomes.

Results: One hundred twenty-two patients with 167 lesions were identified. Twenty-two lesions (13%) previously underwent open resection, and 131 lesions (78%) had prior external beam radiotherapy. The median single-fraction dose for 145 lesions was 16 Gy (range: 12-20). Multi-fractionated treatments for 22 lesions utilized doses of 18-30 Gy in 2-5 fractions. Median follow-up for the cohort was 4 months (range: 1-133). Local progression occurred in 15 lesions (9%) at a median of 5 months (range: 1-11). Rates of LC were 88%, 75%, and 75% at 6 months, 1 year, and 2 years, respectively. No individual prognostic variables were associated with LC. Pain outcomes improved or remained stable for 106 lesions (77%). Local progression (p < 0.01, HR: 5.2, 95% CI: 1.5-18.3) was associated with the progression of pain. Rates of OS were 45%, 22%, and 8% at 6 months, 1 year, and 2 years, respectively. Karnofsky Performance Score > 80 (p = 0.03, HR: 1.8, 95% CI: 1.1-3.0) was associated with superior OS. Twenty-nine AREs (17%), including 12 vertebral compression fractures (7%), were observed.

Conclusion : In a large cohort of patients with spinal lung metastases, radiosurgery was demonstrated to be safe and effective for both LC and pain relief.