Proton versus photon adjuvant radiotherapy: a multicenter comparative evaluation of recurrence following spinal chordoma resection.

OBJECTIVE: Chordomas are rare tumors of the skull base and spine believed to arise from the vestiges of the embryonic notochord. These tumors are locally aggressive and frequently recur following resection and adjuvant radiotherapy. Proton therapy has been introduced as a tissue-sparing option because of the higher level of precision that proton-beam techniques offer compared with traditional photon radiotherapy. This study aimed to compare recurrence in patients with chordomas receiving proton versus photon radiotherapy following resection by applying tree-based machine learning models. METHODS: The clinical records of all patients treated with resection followed by adjuvant proton or photon radiotherapy for chordoma at Mayo Clinic were reviewed. Patient demographics, type of surgery and radiotherapy, tumor recurrence, and other variables were extracted. Decision tree classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS: Fifty-three patients with a mean ± SD age of 55.2 ± 13.4 years receiving surgery and adjuvant proton or photon therapy to treat chordoma were identified; most patients were male. Gross-total resection was achieved in 54.7% of cases. Proton therapy was the most common adjuvant radiotherapy (84.9%), followed by conventional or external-beam radiation therapy (9.4%) and stereotactic radiosurgery (5.7%). Patients receiving proton therapy exhibited a 40% likelihood of having recurrence, significantly lower than the 88% likelihood observed in those treated with nonproton therapy. This was confirmed on logistic regression analysis adjusted for extent of tumor resection and tumor location, which revealed that proton adjuvant radiotherapy was associated with a decreased risk of recurrence (OR 0.1, 95% CI 0.01-0.71; p = 0.047) compared with photon therapy. The decision tree algorithm predicted recurrence with an accuracy of 90% (95% CI 55.5%-99.8%), with the lowest risk of recurrence observed in patients receiving gross-total resection with adjuvant proton therapy (23%). CONCLUSIONS: Following resection, adjuvant proton therapy was associated with a lower risk of chordoma recurrence compared with photon therapy. The described machine learning models were able to predict tumor progression based on the extent of tumor resection and adjuvant radiotherapy modality used.

Immunohistochemical markers predicting long-term recurrence following clival and spinal chordoma resection: a multicenter study.

OBJECTIVE: Chordomas are rare tumors from notochordal remnants and account for 1%-4% of all primary bone malignancies, often arising from the clivus and sacrum. Despite margin-negative resection and postoperative radiotherapy, chordomas often recur. Further, immunohistochemical (IHC) markers have not been assessed as predictive of chordoma recurrence. The authors aimed to identify the IHC markers that are predictive of postoperative long-term (≥ 1 year) chordoma recurrence by using trained multiple tree-based machine learning (ML) algorithms. METHODS: The authors reviewed the records of patients who had undergone treatment for clival and spinal chordomas between January 2017 and June 2021 across the Mayo Clinic enterprise (Minnesota, Florida, and Arizona). Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient record. Decision tree and random forest classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS: One hundred fifty-one patients diagnosed and treated for chordomas were identified: 58 chordomas of the clivus, 48 chordomas of the mobile spine, and 45 chordomas sacrococcygeal in origin. Patients diagnosed with cervical chordomas were the oldest among all groups (58 ± 14 years, p = 0.009). Most patients were male (n = 91, 60.3%) and White (n = 139, 92.1%). Most patients underwent resection with or without radiation therapy (n = 129, 85.4%). Subtotal resection followed by radiation therapy (n = 51, 33.8%) was the most common treatment modality, followed by gross-total resection then radiation therapy (n = 43, 28.5%). Multivariate analysis showed that S100 and pan-cytokeratin are more likely to predict the increase in the risk of postoperative recurrence (OR 3.67, 95% CI 1.09-12.42, p= 0.03; and OR 3.74, 95% CI 0.05-2.21, p = 0.02, respectively). In the decision tree analysis, a clinical follow-up > 1897 days was found in 37% of encounters and a 90% chance of being classified for recurrence (accuracy = 77%). Random forest analysis (n = 500 trees) showed that patient age, type of surgical treatment, location of tumor, S100, pan-cytokeratin, and EMA are the factors predicting long-term recurrence. CONCLUSIONS: The IHC and clinicopathological variables combined with tree-based ML tools successfully demonstrated a high capacity to identify recurrence patterns with an accuracy of 77%. S100, pan-cytokeratin, and EMA were the IHC drivers of recurrence. This shows the power of ML algorithms in analyzing and predicting outcomes of rare conditions of a small sample size.

Impact of tumor-associated syrinx on outcomes following resection of primary ependymomas of the spinal cord.

PURPOSE: To interrogate the association of tumor-associated syrinxes with postoperative neurological and oncological outcomes in patients surgically treated for WHO grade 2 spinal ependymomas. METHODS: Adults treated for primary spinal intramedullary ependymomas between 2000 and 2020 were identified and data were gathered on preoperative neurological exam, radiographic characteristics, operative details, and postoperative neurological outcome. Neurological status was graded on the modified McCormick Scale (MMS). Neurological worsening immediately postoperatively and at last follow-up were defined by ≥ 1 MMS grade deterioration. Decision-tree analyses were also performed to identify independent predictors of new neurological deficits. RESULTS: Seventy patients were identified; mean age 45.4 ± 12.7; 60% male. Forty-eight patients (68.6%) had tumor-associated syrinxes, were more common among males (68.8%) and cervical lesions (68.8 vs. 31.8%; P = 0.005). Postoperatively patients with syrinxes had better MMS (P = 0.035) and were less likely to require a gait aid (39.6 vs. 81.8; P = 0.002). This latter difference persisted to last follow-up (22.9 vs. 59.1%; P = 0.006). On decision-tree analysis the strongest predictors of long-term neurological worsening were advanced age (≥ 63 years) and worse baseline neurological function. Worsened neurological status in the immediate postoperative period was best predicted by thoracic localization, the presence of a hemosiderin cap, and longer craniocaudal extension. CONCLUSION: For spinal ependymomas, tumor-associated syrinxes may portend decreased risk for immediate postoperative neurologic deficits but do not predict long-term neurological outcomes (MMS) or odds of successful gross total resection. Thoracic localization appears to best predict new immediate postoperative deficits, and worse baseline neurological function and advanced age best predict long-term deficits.

Focused versus conventional radiotherapy in spinal oncology: is there any difference in fusion rates and pseudoarthrosis?

INTRODUCTION: Radiotherapy is considered standard of care for adjuvant peri-operative treatment of many spinal tumors, including those with instrumented fusion. Unfortunately, radiation treatment has been linked to increased risk of pseudoarthrosis. Newer focused radiotherapy strategies with enhanced conformality could offer improved fusion rates for these patients, but this has not been confirmed. METHODS: We performed a retrospective analysis of patients at three tertiary care academic institutions with primary and secondary spinal malignancies that underwent resection, instrumented fusion, and peri-operative radiotherapy. Two board certified neuro-radiologists used the Lenke fusion score to grade fusion status at 6 and 12-months after surgery. Secondary outcomes included clinical pseudoarthrosis, wound complications, the effect of radiation timing and radiobiological dose delivered, the use of photons versus protons, tumor type, tumor location, and use of autograft on fusion outcomes. RESULTS: After review of 1252 spinal tumor patients, there were 60 patients with at least 6 months follow-up that were included in our analyses. Twenty-five of these patients received focused radiotherapy, 20 patients received conventional radiotherapy, and 15 patients were treated with protons. There was no significant difference between the groups for covariates such as smoking status, obesity, diabetes, intraoperative use of autograft, and use of peri-operative chemotherapy. There was a significantly higher rate of fusion for patients treated with focused radiotherapy compared to those treated with conventional radiotherapy at 6-months (64.0% versus 30.0%, Odds ratio: 4.15, p = 0.036) and 12-months (80.0% versus 42.1%, OR: 5.50, p = 0.022). There was a significantly higher rate of clinical pseudoarthrosis in the conventional radiotherapy cohort compared to patients in the focused radiotherapy cohort (19.1% versus 0%, p = 0.037). There was no difference in fusion outcomes for any of the secondary outcomes except for use of autograft. The use of intra-operative autograft was associated with an improved fusion at 12-months (66.7% versus 37.5%, OR: 3.33, p = 0.043). CONCLUSION: Focused radiotherapy may be associated with an improved rate of fusion and clinical pseudoarthrosis when compared to conventional radiation delivery strategies in patients with spinal tumors. Use of autograft at the time of surgery may be associated with improved 12-month fusion rates. Further large-scale prospective and randomized controlled studies are needed to better stratify the effects of radiation delivery modality in these patients.

Assessment of neurosurgical resident milestone evaluation reporting and feedback processes.

OBJECTIVE: Structured performance evaluations are important for the professional development and personal growth of resident learners. This process is formalized by the Accreditation Council for Graduate Medical Education milestones assessment system. The primary aim of this study was to understand the current feedback delivery mechanism by exploring the culture of feedback, the mechanics of delivery, and the evaluation of the feedback itself. METHODS: Face-to-face interviews were conducted with 10 neurosurgery residents exploring their perceptions of summative feedback. Coded data were analyzed qualitatively for overriding themes using the matrix framework method. A priori themes of definition of feedback, feedback delivery, and impact of feedback were combined with de novo themes discovered during analysis. RESULTS: Trainees prioritized formative over summative feedback. Summative and milestone feedback were criticized as being vague, misaligned with practice, and often perceived as erroneous. Barriers to implementation of summative feedback included perceived veracity of feedback, high interrater variability, and the inconstant adoption of a developmental progression model. Gender bias was noted in degree of feedback provided and language used. CONCLUSIONS: Trainee perception of feedback provided multiple areas of improvement. This paper can serve as a baseline to study improvements in the milestone feedback process and optimize learning.

Clinical characteristics and management differences for grade II and III spinal meningiomas.

PURPOSE: The majority of spinal meningiomas are grade I tumors, as defined by World Health Organization (WHO) classification making atypical (grade II) or anaplastic (grade III) tumors extremely rare lesions to encounter in clinical practice. Here, we present our institutional experience of management of grade II and III spinal meningiomas. METHODS: Following IRB approval, we queried all available institutional electronic medical records for patients undergoing surgical resection of pathology-proven spinal meningiomas, with further review of patients with grade II and III. Variables of interest included age, sex, histological type, tumor size, symptoms at baseline, treatment characteristics, symptom resolution at the last follow-up, recurrence, NF-2 status, concurrent intracranial meningioma, and mortality. Kaplan Meier curves were constructed to study time to progression/recurrence. RESULTS: A total of 188 patients undergoing surgical resection of spinal meningioma between 1988 and 2018 were identified. Among those, 172 (91.5%) patients had grade I meningioma and 16 (8.5%) patients had high grade meningiomas [grade II (15) and III (1)]. Over a median (IQR) follow-up of 8.0 years (5.1-13.0), mortality and recurrence rates were 18.8% (n = 3) and 47.1% (n = 8), respectively. In univariate analysis, adjuvant radiotherapy and thoracic segment involvement were associated with lower rates of recurrence while male sex was associated with a higher rate of recurrence. CONCLUSIONS: Results showed variations in clinical outcomes for patients with high grade spinal meningiomas, especially the recurrence. Adjuvant radiotherapy and thoracic segment involvement was associated with lower rates of recurrence while recurrence ocurred at a higher rate in males.

Cervical chordomas: multicenter case series and meta-analysis.

BACKGROUND: En bloc spondylectomy is the gold standard for surgical resection of sacral chordomas (CHO), but the effect of extent of resection on recurrence and survival in patients with CHO of the cervical spine remains elusive. METHODS: MEDLINE, Embase, Scopus, and Cochrane were systematically reviewed. Patients with cervical CHO treated at three tertiary-care academic institutions were reviewed for inclusion. We performed an individual participant data meta-analysis to assess the overall survival (OS) and progression free survival (PFS) after en bloc-gross total resection (GTR) and intralesional-GTR compared to subtotal resection (STR). We then performed an intention-to-treat analysis including all patients with attempted en bloc resection in the en bloc group, regardless of the surgical margins. RESULTS: There was a total of 13 series including 161 patients with cervical CHO, including our current series of 22 patients. GTR (en bloc-GTR + intralesional-GTR) was associated with a significant decrease in the risk of local progression (pooled hazard ratio (PHR) = 0.22; 95% CI 0.08-0.59; p = 0.003) and risk of death (PHR 0.31; 95%; CI 0.12-0.83; p = 0.020). A meta-regression analyses determined that intralesional-GTR improved PFS (PHR 0.35; 95% CI 0.16-0.76; p = 0.009) as well as OS (PHR 0.25; 95% CI 0.08-0.79; p = 0.019) when compared to STR. En bloc-GTR was associated with a significant reduction in the risk of local progression (PHR 0.06; 95% CI 0.01-0.77; p = 0.030), but not a decreased OS (PHR 0.50; 95% CI 0.19-1.27; p = 0.145). Our intention-to-treat analyses revealed a near significant improvement in OS for the en bloc group (PHR: 0.15; 95% CI 0.02-1.22; p = 0.054), and nearly identical improvement in PFS. Radiation data was not available for the studies included in the meta-analysis. CONCLUSION: This is the first and only meta-analysis of patients with cervical CHO. We found that both en bloc-GTR and intralesional-GTR resulted in improved local tumor control when compared to STR.

Surgical treatment of primary mobile spine chordoma.

BACKGROUND AND OBJECTIVES: Chordomas of the mobile spine (C1-L5) are rare malignant tumors. The purpose of this study was to review the outcome of surgical treatment for patients with primary mobile spine chordomas. METHODS: The oncologic outcomes and survival of 26 patients undergoing surgical resection for a primary mobile spine chordoma were assessed over a 25-year period. The mean follow-up was 12 ± 6 years. RESULTS: The 2-, 5-, and 10-year disease-free survivals were 95%, 61%, and 55%. The local recurrence-free survival was improved in patients receiving en bloc resection with negative margins (83% vs. 35%, p = 0.02) and similar in patients receiving adjuvant radiation therapy (43% vs. 45%, p = 0.30) at 10 years. Debulking of the tumor (hazard ratio [HR] = 6.41, p = 0.01) and a local recurrence (HR = 9.52, p = 0.005) were associated with death due to disease. Complications occurred in 19 (73%) patients, leading to reoperation in 9 (35%) patients; this rate was similar in intralesional and en bloc procedures. CONCLUSION: Surgical resection of mobile spine chordomas is associated with a high rate of complications; however, en bloc resection can provide a hope for cure and appears to confer better oncologic outcomes for these tumors without an increase in complications compared to lesser resections.

International trends in grant and fellowship funding awarded to women in neurosurgery.

OBJECTIVE: Metric tracking of grant funding over time for academic neurosurgeons sorted by gender informs the current climate of career development internationally for women in neurosurgery. METHODS: Multivariate linear trend analysis of grant funding awarded to neurosurgeons in the NIH and World Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) was performed. Traveling fellowships for international neurosurgery residents sponsored by the AANS and Congress of Neurological Surgeons (CNS) were also analyzed. RESULTS: Within the US, funding awarded to female neurosurgeons has remained static from 2009 to 2019 after adjusting for inflation and overall trends in NIH funding (ß = -$0.3 million per year, p = 0.16). Internationally, female neurosurgeons represented 21.7% (n = 5) of project leads for World RePORTER grants. Traveling fellowships are also an important building block for young international female neurosurgeons, of which 7.4% (n = 2) of AANS international traveling fellowships and 19.4% (n = 7) of AANS/CNS pediatrics international traveling fellowships are women. CONCLUSIONS: Over the past decade, funding has increased in neurosurgery without a concordant increase in funding awarded to women. Recognition of this trend is essential to focus efforts on research and career development opportunities for women in neurosurgery. Worldwide, female neurosurgeons head one-fifth of the funded project leads and constitute a minority of international traveling fellowships awarded by organized neurosurgery.

Feasibility of achieving planned surgical margins in primary spine tumor: a PTRON study.

OBJECTIVE: Oncological resection of primary spine tumors is associated with lower recurrence rates. However, even in the most experienced hands, the execution of a meticulously drafted plan sometimes fails. The objectives of this study were to determine how successful surgical teams are at achieving planned surgical margins and how successful surgeons are in intraoperatively assessing tumor margins. The secondary objective was to identify factors associated with successful execution of planned resection. METHODS: The Primary Tumor Research and Outcomes Network (PTRON) is a multicenter international prospective registry for the management of primary tumors of the spine. Using this registry, the authors compared 1) the planned surgical margin and 2) the intraoperative assessment of the margin by the surgeon with the postoperative assessment of the margin by the pathologist. Univariate analysis was used to assess whether factors such as histology, size, location, previous radiotherapy, and revision surgery were associated with successful execution of the planned margins. RESULTS: Three hundred patients were included. The surgical plan was successfully achieved in 224 (74.7%) patients. The surgeon correctly assessed the intraoperative margins, as reported in the final assessment by the pathologist, in 239 (79.7%) patients. On univariate analysis, no factor had a statistically significant influence on successful achievement of planned margins. CONCLUSIONS: In high-volume cancer centers around the world, planned surgical margins can be achieved in approximately 75% of cases. The morbidity of the proposed intervention must be balanced with the expected success rate in order to optimize patient management and surgical decision-making.

Association of neurologic deficits with surgical outcomes and health-related quality of life after treatment for metastatic epidural spinal cord compression.

BACKGROUND: A critical knowledge gap exists regarding the impact of neurologic deficits on surgical outcomes and health-related quality of life (HRQOL) for patients surgically treated for metastatic epidural spinal cord compression (MESCC). METHODS: This prospective, multicenter and international study analyzed the impact of the neurologic status on functional status, HRQOL, and postoperative survival. The collected data included the patient demographics, overall survival, American Spinal Injury Association (ASIA) impairment scale, Spinal Instability Neoplastic Score, treatment details and complications and HRQOL measures, including version 2 of the 36-Item Short Form Health Survey (SF-36v2) and version 2.0 of the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0). RESULTS: A total of 239 patients surgically treated for spinal metastases were included. Six weeks after treatment, 99 of the 108 patients with a preoperative ASIA grade of E remained stable, 8 deteriorated to ASIA D, and 1 deteriorated to ASIA A. Of 55 patients with ASIA D, 27 improved to ASIA E, 27 remained stable and 1 deteriorated to ASIA C. Of 11 patients with ASIA A to C, 2 improved to ASIA E, 4 improved to ASIA D, and 5 remained stable. At the 6- and 12-week follow-up, better ASIA scores were associated with better scores on multiple SF-36v2 and SOSGOQ items. Postoperatively, patients with ASIA grades of A to D were more likely to have urinary tract infections and wound complications. Patients with a baseline ASIA grade of E or D survived significantly longer. CONCLUSIONS: Patients with neurologic deficits due to MESCC have worse HRQOL and decreased overall survival. Nevertheless, surgery can result in stabilization or improvement of neurologic function which may translate into better HRQOL. Postoperative care and follow-up are challenging for patients with neurologic deficits because they experience more complications.

Survival, local control, and health-related quality of life in patients with oligometastatic and polymetastatic spinal tumors: A multicenter, international study.

BACKGROUND: The treatment of oligometastatic (≤5 metastases) spinal disease has trended toward ablative therapies, yet to the authors' knowledge little is known regarding the prognosis of patients presenting with oligometastatic spinal disease and the value of this approach. The objective of the current study was to compare the survival and clinical outcomes of patients with cancer with oligometastatic spinal disease with those of patients with polymetastatic (>5 metastases) disease. METHODS: The current study was an international, multicenter, prospective study. Patients who were admitted to a participating spine center with a diagnosis of spinal metastases and who underwent surgical intervention and/or radiotherapy between August 2013 and May 2017 were included. Data collected included demographics, overall survival, local control, and treatment information including surgical, radiotherapy, and systemic therapy details. Health-related quality of life (HRQOL) measures included the EuroQOL 5 dimensions 3-level questionnaire (EQ-5D-3L), the 36-Item Short Form Health Survey (SF-36v2), and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ). RESULTS: Of the 393 patients included in the current study, 215 presented with oligometastatic disease and 178 presented with polymetastatic disease. A significant survival advantage of 90.1% versus 77.3% at 3 months and 77.0% versus 65.1% at 6 months from the time of treatment was found for patients presenting with oligometastatic disease compared with those with polymetastatic disease. It is important to note that both groups experienced significant improvements in multiple HRQOL measures at 6 months after treatment, with no differences in these outcome measures noted between the 2 groups. CONCLUSIONS: The treatment of oligometastatic disease appears to offer a significant survival advantage compared with polymetastatic disease, regardless of treatment choice. HRQOL measures were found to improve in both groups, demonstrating a palliative benefit for all treated patients.

Patient satisfaction with treatment outcomes after surgery and/or radiotherapy for spinal metastases.

BACKGROUND: Patient satisfaction is infrequently investigated despite its importance in assessing efficacy and patient comprehension. The purpose of this study was to investigate patient satisfaction with treatment outcomes after surgery and/or radiotherapy for spinal metastases and to evaluate how health-related quality of life (HRQOL) is related to patient satisfaction. METHODS: Patients with spinal metastases treated with surgery and/or radiotherapy were enrolled in a prospective, international, observational study. Demographic, histologic, treatment, and HRQOL data were collected. HRQOL was evaluated with the Numeric Rating Scale pain score, the 3-level version of the EuroQol 5-Dimension (EQ-5D-3L) instrument, and the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ2.0). Patient satisfaction was derived from the SOSGOQ2.0 at 6, 12, and 26 weeks after treatment. Patients were classified as satisfied, neutral, or dissatisfied. RESULTS: Twelve weeks after treatment, 183 of the surgically treated patients (84%) were satisfied, and only 11 (5%) were dissatisfied; in contrast, 101 of the patients treated with radiotherapy alone (77%) were satisfied, and only 7 (5%) were dissatisfied. Significant improvements in pain, physical function, mental health, social function, leg function, and EQ-5D were associated with satisfaction after surgery. Satisfaction after radiotherapy was associated with significant improvements in pain, mental health, and overall SOSGOQ2.0 scores. Dissatisfaction after treatment was associated with lower baseline values for leg strength and lower social functioning scores for surgically treated patients and with lower social functioning scores and being single for patients treated with radiotherapy. CONCLUSIONS: High levels of satisfaction with treatment outcomes are observed after surgery and/or radiotherapy for spinal metastases. Posttreatment satisfaction is associated with significant improvements in pain and different dimensions of HRQOL.

Subependymoma involving multiple spinal cord levels: A clinicopathological case series with chromosomal microarray analysis.

Subependymomas of the spinal cord are rare, do not often involve multiple levels, and very rarely recur. Here, we present a series of spinal cord subependymomas with a detailed description of the clinical, radiological and pathological features, and characterization by chromosomal microarray analysis. Briefly, the four patients included two men and two women, between the ages of 22 and 48 years. The most common presenting symptoms were neck and arm pain with upper extremity weakness. By imaging, the tumors were found to involve multiple spinal levels, including cervical/ cervico-thoracic (three patients) and thoracic (one patient), were all eccentric, and had minimal to no post-contrast enhancement. Two patients underwent gross total resection, one had a sub-total resection, and one underwent biopsy alone with a decompressive laminectomy. Follow up ranged from 6 months to 22 years. One patient (case 4) had recurrence 15 years following gross total resection and chromosomal microarray analysis revealed deletions on the long arm of chromosome 6. Our limited series suggests that spinal cord subependymomas can rarely recur, even following gross total resection, suggesting a possible role for long-term surveillance for these rare tumors.

Psychometric evaluation and adaptation of the Spine Oncology Study Group Outcomes Questionnaire to evaluate health-related quality of life in patients with spinal metastases.

BACKGROUND: The Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ) was developed as the first spine oncology-specific health-related quality of life (HRQOL) measure. This study evaluated the psychometric properties and clinical validity of the SOSGOQ in a diverse cohort of patients with spinal metastases. METHODS: An international, multicenter, prospective observational cohort study including patients with spinal metastases who underwent surgery and/or radiotherapy was conducted by the AOSpine Knowledge Forum Tumor. Demographic, tumor, and treatment data were collected. HRQOL was evaluated using the SOSGOQ and Medical Outcomes Study Questionnaire Short Form 36 Health Survey (SF-36) at baseline and fixed follow-up times. Construct validity was assessed using multitrait scaling analyses, confirmatory factor analyses, and correlation with the SF-36 and NRS pain score. Test-retest reliability was assessed in a subgroup of patients between 12 weeks after treatment and the retest 4 to 9 days later. RESULTS: A total of 238 patients were enrolled at 9 centers across North America; 153 of these patients had HRQOL data available at 12 weeks after treatment. Multitrait scaling analyses and confirmatory factor analyses resulted in a refined version of the SOSGOQ with 4 domains and 4 single items. The revised SOSGOQ (SOSGOQ2.0) demonstrated strong correlations with SF-36 and the ability to discriminate between clinically distinct patient groups. Reliability of the SOSGOQ2.0 was demonstrated to be good, with an intraclass correlation coefficient ranging from 0.58 to 0.92 for the different domains. CONCLUSIONS: The SOSGOQ2.0 is a reliable and valid measure with which to evaluate HRQOL in patients with spinal metastases. It is recommended to use the SOSGOQ2.0 together with a generic HRQOL outcome measure to comprehensively assess HRQOL and increase sensitivity and specificity. Cancer 2018;124:1828-38. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.