Postoperative re-irradiation using stereotactic body radiotherapy for metastatic epidural spinal cord compression

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>This study aimed to clarify the outcomes of postoperative re-irradiation using stereotactic body radiotherapy (SBRT) for metastatic epidural spinal cord compression (MESCC) in the authors’ institution and to identify factors correlated with local control.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Cases in which patients with previously irradiated MESCC underwent decompression surgery followed by spine SBRT as re-irradiation between April 2013 and May 2017 were retrospectively reviewed. The surgical procedures were mainly performed by the posterior approach and included decompression and fixation. The prescribed dose for spine SBRT was 24 Gy in 2 fractions. The primary outcome was local control, which was defined as elimination, shrinkage, or no change of the tumor on CT or MRI obtained approximately every 3 months after SBRT. In addition, various patient-, treatment-, and tumor-specific factors were evaluated to determine their predictive value for local control.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>Twenty-eight cases were identified in the authors’ institutional databases as meeting the inclusion criteria. The histology of the primary disease was thyroid cancer in 7 cases, lung cancer in 6, renal cancer in 3, colorectal cancer in 3, and other cancers in 9. The most common previous radiation dose was 30 Gy in 10 fractions (15 cases). The mean interval since the most recent irradiation was 16 months (range 5–132 months). The median duration of follow-up after SBRT was 13 months (range 4–38 months). The 1-year local control rate was 70%. In the analysis of factors related to local control, Bilsky grade, number of vertebral levels in the treatment target, the interval between the latest radiotherapy and SBRT, recursive partitioning analysis (RPA), the prognostic index for spinal metastases (PRISM), and the revised Tokuhashi score were not significantly correlated with local control. The favorable group classified by the Rades prognostic score achieved a significantly higher 1-year local control rate than the unfavorable group (1-year local control rate: 100% vs 33%; p &lt; 0.01). Radiation-induced myelopathy and vertebral compression fracture were observed in 1 and 3 patients, respectively. No other grade 3 or greater toxicities were encountered.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>The results indicate that spine SBRT as postoperative re-irradiation was effective, and it was especially useful for patients classified as having a good survival prognosis according to the Rades score.</jats:p></jats:sec>

Separation surgery for metastatic epidural spinal cord compression: A qualitative review

“…Recently, Redmond et al reported results from the first prospective study analyzing post-operative SBRT (30 Gy in 5 fractions), showing 1-year LC of 91.4% [59] . Notably, Ito et al analyzed a retrospective series of 28 patients previously treated with cEBRT, who underwent surgery and subsequent re-irradiation with SBRT (24 Gy in 2 fractions), reporting 1-year LC of 70%, showing SBRT feasibility even for re-irradiation [60] .…”

Stereotactic Radiosurgery for Postoperative Spine Malignancy: A Systematic Review and International Stereotactic Radiosurgery Society Practice Guidelines

“…A total of 461 patients and 499 segments treated across 12 studies were included in this analysis. [14][15][16][17][18][19][20][21][22][23][24][25] Surgical techniques were heterogenous, and a description of technique used per study is outlined in Table 2. Seven studies were retrospective by design, two were prospective observational and three were prospective phase I/II clinical trials.…”

“…The median time interval between surgery and SBRT was reported by five of the included studies and ranged from 14 days to 45 days. [14][15][16]21,22 Two studies reported the mean time as 14 days and 44 days, and a further two investigators treated patients within 2 months and 4 months, respectively. 19,20,23,24 The two studies that reported a median and mean time of 14 days were investigations of MIS and percutaneous treatment of vertebral body tumors, respectively.…”

Improvement of Metastatic Spinal Cord Compression After Decompression Surgery and Radiotherapy in a Patient Initially Treated for Rectal Cancer

“…Regarding dose fractionation in radiotherapy, while single irradiation is said to maintain motor function and bladder function at the same level as multiple irradiations, some reports indicate that higher doses provide a higher local control rate. In recent years, stereotactic radiotherapy (SRT) is also being used [5,12]. Moulding HD et al studied 21 patients who underwent SRT after spinal decompression and fixation and reported that 24 Gy/1 fraction controlled the tumor regardless of the tumor's radiation sensitivity [5].…”