Phase II Clinical Trial of Separation Surgery Followed by Stereotactic Body Radiotherapy for Metastatic Epidural Spinal Cord Compression

Abstract

Stereotactic body radiotherapy (SBRT) is a postoperative treatment option for spinal metastases. As data on surgery with SBRT are limited to retrospective studies, this single-center, single-arm, phase II study prospectively evaluated the outcomes of separation surgery and SBRT for metastatic epidural spinal cord compression (MESCC).Patients with symptomatic MESCC from solid carcinoma were enrolled. Protocol treatments comprised separation surgery and spine SBRT. Surgical procedures were performed via the posterior approach, with decompression and a fixation procedure. The prescribed dose for spine SBRT was 24 Gy in two fractions. The primary endpoint was the 12-month local failure (LF) rate. Secondary endpoints were ambulatory functions and adverse effects.Thirty-three patients were registered during November 2017-October 2019. All patients satisfied the inclusion criteria, and all but one completed the protocol treatment. Twenty-three patients (70%) had radioresistant lesions. The Bilsky grade at registration was 1c, 2, and 3 in 4, 8, and 21 patients, respectively. The median follow-up duration after registration was 15 (range 3-35) months. Ninety percent of patients (26/29) had Bilsky grade 1 or less disease at 3 months after protocol treatments. The 12-month LF rate was 13%. Twenty patients could walk normally or with a cane 12 months after registration. Radiation-induced myelopathy, radiculopathy, and vertebral compression fracture were observed in 0, 1, and 6 patients, respectively.Separation surgery with SBRT for MESCC was effective in decompression and long-term local control. These findings warrant larger randomized controlled trials to compare SBRT with conventional radiotherapy.