Spinal stereotactic body radiotherapy following intralesional curettage with separation surgery for initial or salvage chordoma treatment

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Chordoma is a rare malignant tumor for which en bloc resection with wide margins is advocated as primary treatment. Unfortunately, due to anatomical constraints, en bloc resection to achieve wide or marginal margins is not feasible for many patients as the resulting morbidity would be prohibitive. The objective of this study was to evaluate the efficacy of intralesional curettage and separation surgery followed by spinal stereotactic body radiation therapy (SBRT) in patients with chordomas in the mobile spine.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>The authors performed a retrospective chart review of all patients with chordoma in the mobile spine treated from 2004 to 2016. Patients were identified from a prospectively collected database. Initially 22 patients were identified with mobile spine chordomas. With inclusion criteria of cytoreductive separation surgery followed closely by SBRT and a minimum of 6 months of follow-up imaging, 12 patients were included. Clinical and pathological characteristics of each patient were collected and data were analyzed. Patients were divided into two cohorts—those undergoing intralesional resection followed by SBRT as initial chordoma treatment at Memorial Sloan Kettering Cancer Center (MSKCC) (Cohort 1) and those undergoing salvage treatment following recurrence (Cohort 2). Treatment toxicities were classified according to the Common Terminology Criteria for Adverse Events version 4.03. Overall survival was analyzed using Kaplan-Meier analysis.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>The 12 patients had a median post-SBRT follow-up time of 26 months. Cohort 1 had 5 patients with median post-SBRT follow-up time of 65.9 months and local control rate of 80% at last follow-up. Only one patient had disease progression, at 48.2 months following surgery and SBRT. Cohort 2 had 7 patients who had been treated at other institutions prior to undergoing both surgery and SBRT (salvage therapy) at MSKCC. The local control rate was 57.1% and the median follow-up duration was 10.7 months. One patient required repeat irradiation. Major surgery- and radiation-related complications occurred in 18% and 27% of patients, respectively. Epidural spinal cord compression scores were collected for each patient pre- and postoperatively.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>The combination of surgery and SBRT provides excellent local control following intralesional curettage and separation surgery for chordomas in the mobile spine. Patients who underwent intralesional curettage and spinal SBRT as initial treatment had better disease control than those undergoing salvage therapy. High-dose radiotherapy may offer several biological benefits for tumor control.</jats:p></jats:sec>

Primary Bone Tumor of the Spine—An Evolving Field: What a General Spine Surgeon Should Know

“…39 Although the main application has been in the treatment of metastatic spine disease, spine SBRT is evolving into the management of primary spinal tumors. For spinal chordoma, treatment with high-dose SBRT has been reported with encouraging local tumor control results 40 ; however, it represents a major departure from established practice of protracted radiation delivery with intensity modulated photon radiotherapy or proton particle-based radiation (eg, 78 Gy in 39 fractions). 41 At present the use of spine SBRT remains investigational for chordoma and should be performed on clinical trial.…”

Stereotactic Body Radiation Therapy for Spinal Malignancies

“…Of the patients, 18% had RT-related major complications, including dysphagia, mucositis, and vocal cord paralysis. 84 …”

“…Of the patients, 18% had RT-related major complications, including dysphagia, mucositis, and vocal cord paralysis. 84 Another study included 20 patients with either chordoma or chondrosarcoma, 20% of which were in sacrum and 15% in spine (remainder skull base). They were treated to a median dose of 37.5 Gy in 5 fractions (range 25-40 Gy).…”

Chordoma of the mobile spine and sacrum: clinical management and prognosis

“…Using their technique of a two-stage modified en bloc spondylectomy employing threadwire, a negative margin rate of 94% was achieved (20). New data suggests that en bloc resection may not be necessary if intralesional debulking and separation surgery are followed by stereotactic body radiation (21). Although, this is a single institution study and additional follow up and reproducibility of the results from other centers is needed.…”