Postoperative Edge (RapidArc) Stereotactic Body Radiotherapy for Spinal Metastases

Prognostic Study of Postoperative Edge (RapidArc) Stereotactic Body Radiotherapy for Spinal Metastases From Solid Tumors

This study observes the effectiveness of high-precision radiation therapy using the Edge system after surgery for patients with spinal metastases. Spinal metastases can press on the spinal cord and cause pain, weakness, or paralysis. This treatment uses higher doses of radiation in fewer sessions (hypofractionated stereotactic body radiotherapy) delivered precisely by the Edge machine to target remaining tumor cells while protecting the spinal cord. The study aims to see if this approach improves local tumor control, improves neurological function, shortens treatment duration, and improves quality of life in these patients. The study is observational, meaning patients receive standard care, and data is collected to evaluate the outcomes.

This is a single-center, prospective, observational cohort study conducted at Tianjin Medical University Cancer Institute and Hospital to evaluate the clinical outcomes of postoperative Edge (RapidArc) Stereotactic Body Radiotherapy (SBRT) in patients with spinal metastases from solid tumors. A total of 50 patients with postoperative metastatic epidural spinal cord compression (MESCC) will be enrolled. The treatment protocol prescribes a total dose of 35 Gy in 5 fractions (7 Gy per fraction) delivered using the Edge system. The Edge system features sub-millimeter precision, six-dimensional dynamic positioning, and optical surface monitoring (OSMS), which allows for a steep dose gradient, high biological effective dose (BED), and maximal spinal cord protection. The study will evaluate local control rate (LC) and neurological improvement (Frankel score) at 3 months as the primary outcome. Secondary outcomes include 1-year and 2-year LC, neurological deterioration-free survival (NDFS), overall survival (OS), and quality of life (EORTC QLQ-C30). Adverse events including acute radiation myelitis and esophagitis will be monitored. Data will be analyzed using SPSS 27.0 and R 4.3.2, with survival curves generated via the Kaplan-Meier method and Cox regression models used for prognostic factor analysis.

Inclusion Criteria:

1. Age 18 to 80 years, any sex.
2. Karnofsky Performance Status (KPS) >= 60 or ECOG Performance Status <= 2.
3. Confirmed spinal metastases from solid tumors by pathology or imaging (MRI/CT).
4. Postoperative imaging confirming residual epidural spinal cord compression (MESCC) requiring adjuvant radiotherapy.
5. Number of lesions <= 5, and maximum diameter of a single lesion <= 5 cm.
6. Interval between surgery and radiotherapy <= 4 weeks.
7. Signed informed consent and willingness to participate in the study.

Exclusion Criteria:

1. Uncontrolled primary tumor (e.g., extensive metastasis or progressive disease).
2. Concurrent brain metastases or other active malignancies.
3. Pathological fracture or severe spinal instability requiring emergency surgical intervention.
4. Prior cumulative spinal cord radiation dose exceeding the tolerance threshold (e.g., previous spinal cord Dmax >= 45 Gy).
5. Contraindications to radiotherapy (e.g., severe cardiopulmonary dysfunction, coagulation disorders).
6. Severe postoperative complications (e.g., infection, poor wound healing) requiring delayed radiotherapy.
7. Incomplete or unreliable medical records from external hospitals.
8. Pregnant or lactating women.