Purpose

This prospective phase 3 randomized trial was designed to test whether ultra high single-dose radiation therapy (24 Gy SDRT) improves local control of oligometastatic lesions compared to a standard hypofractionated stereotactic body radiation therapy regimen (3 × 9 Gy SBRT). The secondary endpoint was to assess the associated toxicity and the impact of ablation on clinical patterns of metastatic progression.

Methods and materials

Between November 2010 and September 2015, 117 patients with 154 oligometastatic lesions (≤5/patient) were randomized in a 1:1 ratio to receive 24 Gy SDRT or 3 × 9 Gy SBRT. Local control within the irradiated field and the state of metastatic spread were assessed by periodic whole-body positron emission tomography/computed tomography and/or magnetic resonance imaging. Median follow-up was 52 months.

Results

A total of 59 patients with 77 lesions were randomized to 24 Gy SDRT and 58 patients with 77 lesions to 3 × 9 Gy SBRT. The cumulative incidence of local recurrence for SDRT-treated lesions was 2.7% (95% confidence interval [CI], 0%-6.5%) and 5.8% (95% CI, 0.2%-11.5%) at years 2 and 3, respectively, compared with 9.1% (95% CI, 2.6%-15.6%) and 22% (95% CI, 11.9%-32.1%) for SBRT-treated lesions (P = .0048). The 2- and 3-year cumulative incidences of distant metastatic progression in the SDRT patients were 5.3% (95% CI, 0%-11.1%), compared with 10.7% (95% CI, 2.5%-18.8%) and 22.5% (95% CI, 11.1%-33.9%), respectively, for the SBRT patients (P = .010). No differences in toxicity were observed.

Conclusions

The study confirms SDRT as a superior ablative treatment, indicating that effective ablation of oligometastatic lesions is associated with significant mitigation of distant metastatic progression.

Study Type Retrospective cohort. Introduction The treatment of rare neoplastic conditions is challenging, especially because studies providing high levels of evidence are often lacking. Such is the case with primary tumors of the spine (PTS), which have a low incidence, are pathologically heterogeneous, and have diverse treatment approaches.1 Despite these difficulties, appropriate evidence-based care of these complex patients is imperative. Failure to follow validated oncologic principles may lead to unnecessary mortality and profound morbidity. Objective With the aim of offering patients the most appropriate treatment based on the best available evidence, a novel scientific model was developed and employed. This article outlines this model, which has not only provided significant evidence guiding treatment of this rare condition, but we believe is readily transferrable to other similarly rare conditions. Methods A four-stage approach was employed. (1) Planning: Data from large volume centers were reviewed together with results from a feasibility questionnaire to provide insight into epidemiology, patient volumes, tumor pathology, treatment modalities, and outcomes. (2) Recruitment: Centers with sufficient volume and valid data were enrolled and provided with the necessary infrastructure. This included study coordinators and a secure, Web-based database (REDCap, Vanderbilt University, Nashville, Tennessee, United States) to capture international data from six modules comprising: demographic, clinical, diagnostic, therapeutic, local recurrence, perioperative morbidity fields, and a cross-sectional survey to update survival information. The AOSpine Knowledge Forum Tumor designed these modules and provided funding. Each center received institutional ethics approval. (3) Retrospective stage: Prospectively collected data from all recruited centers were reviewed and analyzed retrospectively. (4) Prospective stage: Following interim analysis, prospective data collection has been implemented. In addition, a PTS bio-bank network has been created to link clinical data with tumor pathology and molecular analysis. Results It took 18 months to implement stages 1 to 3 of this model and stage 4 is ongoing. A total of 1,495 tumor cases were captured and diagnosed as one of the 18 primary spine tumor subtypes listed (Fig. 1). The most prevalent diagnosis was chordoma (n = 344, 23%). There were 674 females and 821 males with a mean age of 43 ± 19 years at the time of surgery. Surgical treatment was performed between 1981 and 2012. The survival at 5 and 10 years postsurgery was 71.9 and 53.3%, respectively, with a median survival of 13 years postsurgery (Fig. 2). Conclusions To date, this is the largest international collection of PTS. This novel scientific model has not only aggregated a large amount of PTS data, but has also established an international collaborative network of spine oncology centers. The access to large volumes of clinical and bio-bank data will generate further research to guide and enhance the clinical management of PTS. This novel scientific model could be of similar tremendous value if applied to other rare neoplastic conditions.

Background:Approximately 40% of metastatic cancer patients will develop spinal metastases. The current report provides recommendations for standardization of metrics used for spinal oncology patient population description and outcome assessment beyond local control endpoints on behalf of the SPIne response assessment in Neuro-Oncology (SPINO) group. Methods:The SPINO group survey was conducted in order to determine the preferences for utilization of clinician-based and patient-reported outcome measures for description of patients with spinal metastases. Subsequently, ClinicalTrials.gov registry was searched for spinal oncology clinical trials, and measures for patient description and outcome reporting were identified for each trial. These two searches were used to identify currently used descriptors and instruments. A literature search was performed focusing on the measures identified in the survey and clinical trial search in order to assess their validity in the metastatic spinal tumor patient population. References for this manuscript were identified through PubMed and Medline searches. Results:Published literature, expert survey, and ongoing clinical trials were used to synthesize recommendations for instruments for reporting of spinal stability, epidural tumor extension, neurological and functional status, and symptom severity. Conclusions:Accurate description of patient population and therapy effects requires a combination of clinician-based and patient-reported outcome measures. The current report provides international consensus recommendations for the systematic reporting of patient- and clinician-reported measures required to develop trials applicable to surgery for spinal metastases and postoperative spine stereotactic body radiotherapy (SBRT).