Marginal Recurrence Requiring Salvage Radiotherapy After Stereotactic Body Radiotherapy for Spinal Metastases

Journal Article · Tue May 01 04:00:00 EDT 2012 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/J.IJROBP.2011.05.067· OSTI ID:22056346

Koyfman, Shlomo A; Djemil, Toufik ^[1]; Burdick, Michael J ^[2]; Woody, Neil; Balagamwala, Ehsan H; Reddy, Chandana A ^[1]; Angelov, Lilyana ^[3]; Suh, John H ^[1]

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1. Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States)
2. Department of Radiation Oncology, Tulane Medical Center, New Orleans, Louisiana (United States)
3. Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States)

Introduction: We sought to quantify and identify risk factors associated with margin recurrence (MR) requiring salvage radiotherapy after stereotactic body radiation therapy (SBRT) for spinal metastases. Methods: We retrospectively reviewed patients with spinal metastases who were treated with single-fraction SBRT between 2006 and 2009. Gross tumor was contoured, along with either the entire associated vertebral body(ies) or the posterior elements, and included in the planning target volume. No additional margins were used. MR was defined as recurrent tumor within one vertebral level above or below the treated lesion that required salvage radiotherapy. Only patients who presented for 3-month post-SBRT follow-up were included in the analysis. Fine and Gray competing risk regression models were generated to identify variables associated with higher risks of MR. MR was plotted using cumulative incidence analysis. Results: SBRT was delivered to 208 lesions in 149 patients. Median follow-up was 8.6 months, and median survival was 12.8 months. The median prescribed dose was 14 Gy (10-16 Gy). MR occurred in 26 (12.5%) treated lesions, at a median time of 7.7 months after SBRT. Patients with paraspinal disease at the time of SBRT (20.8% vs. 7.6% of patients; p = 0.02), and those treated with <16 Gy (16.3% vs. 6.3% of patients, p = 0.14) had higher rates of MR. Both variables were associated with significantly higher risk of MR on multivariate analysis. Conclusion: SBRT for spinal metastases results in a low overall rate of MR. The presence of paraspinal disease at the time of SBRT and a dose of <16 Gy were associated with higher risks of MR.

• OSTI ID: 22056346
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 1 Vol. 83; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
HAZARDS
METASTASES
MULTIVARIATE ANALYSIS
NEOPLASMS
PATIENTS
PLANNING
RADIATION DOSES
RADIOTHERAPY