Stereotactic Body Radiotherapy for Spinal Oligometastases With or Without Simultaneous Integrated Boost: Results From...

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Spinal bone metastases are common, and while radiotherapy is established for symptomatic relief, data on ablative treatments like SBRT are limited.
• Oligometastatic disease, characterized by a limited number of metastatic sites, presents a unique treatment challenge.
• Evaluating novel radiotherapy techniques for spinal oligometastases is crucial for improving patient outcomes.

Purpose of the Study:

• To assess the efficacy and toxicity of stereotactic body radiotherapy (SBRT) for spinal oligometastases.
• To identify factors influencing treatment outcomes, including the use of simultaneous integrated boost (SIB).
• To compare outcomes across different patient histologies.

Main Methods:

• A retrospective analysis of spinal oligometastatic patients treated with SBRT between 2018 and 2023.
• Standardized contouring and treatment planning, with SIB administered to macroscopic disease when feasible.
• Primary endpoint: local progression-free survival (LPFS); Secondary endpoints: toxicity, distant progression-free survival (DPFS), and overall survival (OS).

Main Results:

• 152 spinal oligometastases in 120 patients were treated with a median dose of 24 Gy in 3 fractions.
• One- and 2-year LPFS rates were 92.1% and 90%, respectively.
• SIB significantly improved 2-year LPFS (P=0.037), and prostate cancer patients demonstrated better PMFS and DPFS.

Conclusions:

• Spinal SBRT is an effective treatment modality for spinal oligometastases.
• The administration of a dose boost (SIB) is safe and significantly improves LPFS.
• Prostate cancer patients with spinal oligometastases exhibit more favorable survival outcomes compared to other histologies.