The Role of Adjuvant Radiation in the Management of Solitary Fibrous Tumors of the Central Nervous System: A National Cancer Database Analysis of 155 Patients

Solitary fibrous tumors (SFT) are a rare neoplasm of mesenchymal origin. There is limited evidence on the epidemiology, treatment, and outcomes of SFT in the central nervous system (CNS). The National Cancer Database (NCDB) was queried for patients diagnosed with an SFT in the CNS as their only tumor diagnosis between 2003 and 2011. The final cohort included 155 patients who received surgery and had adequate information for analysis. Descriptive statistics, logistic regression, and Kaplan-Meier survival analyses were performed. Significance was calculated using a t-test, Fisher's exact test, chi-square, log-rank test, or Cox model. Twenty-three patients (15%) underwent both surgery and adjuvant radiation while 132 (85%) underwent surgery alone. The treatment groups had comparable demographics and tumor size; median age 53 (range 25-80) and 11 females (48%) in the surgery and adjuvant radiation group, compared to 55 (20-89) and 71(54%) in the surgery alone group, respectively. Radiotherapy methods included conventional and stereotactic dose and fractionations schemes. Information on margin status and re-resection rates was not available. No variables were significantly associated with receipt of adjuvant radiation. In single (p = 0.78) and multivariable (p = 0.86) survival analyses, the addition of adjuvant radiation did not significantly affect overall survival. Five-year overall survival was 88% with surgery alone versus 93% with adjuvant radiation. SFTs are rare neoplasms, especially in the CNS. Our study did not demonstrate an overall survival benefit for adjuvant radiation. The role of adjuvant radiation is still unclear and warrants further investigation.