(P036) Patterns of Care and Outcomes of Adjuvant Radiotherapy for Meningiomas: A Surveillance, Epidemiology, and End Results and Medicare-Linked Analysis

Mark J. Amsbaugh, MD, Beatrice Ugiliweneza, PhD, MSPH, Eric Burton, MD, Maxwell Boakye, MD, MPH, MBA, Shiao Woo, MD; University of Louisville

PURPOSE: To identify patterns of care and outcomes of adjuvant radiotherapy for meningiomas in the linked Surveillance, Epidemiology, and End Results (SEER) Medicare data.

MATERIALS AND METHODS: Patients over 66 years of age, diagnosed with meningioma, and treated with a craniotomy in the SEER-Medicare data were included. Patients were grouped according to adjuvant treatment with fractionated radiotherapy (XRT), stereotactic radiosurgery (SRS), or none. Demographic, tumor, treatment, and outcome variables were collected. The Mann-Whitney U-test and chi-square test were used to analyze continuous and categorical variables. Time to event was analyzed with the Kaplan-Meier methods and log-rank test. Multivariate comparisons were conducted with logistic regression and proportional hazard models.

RESULTS: A total of 1,964 patients were included for analysis (1,701 with no adjuvant treatment, 175 with XRT, and 88 with SRS). Patients were less likely to receive adjuvant therapy if they were older than 75 years (odds ratio [OR] = 0.730; 95% confidence interval [CI], 0.548–0.973), female (OR = 0.731; 95% CI, 0.547–0.978), or unmarried (OR = 0.692; 95% CI, 0.515–0.929). Patients were more likely to receive adjuvant treatment for grade II/III tumors (OR = 5.586; 95% CI, 2.135–13.589), tumors over 5 cm (OR = 1.850; 95% CI, 1.332–2.567) or partial resection (OR = 3.230; 95% CI, 2.327–4.484). For those receiving adjuvant therapy, SRS was less likely than XRT in patients diagnosed with grade II/III tumors (OR = 0.061; 95% CI, 0.006–0.655) or a 1-unit increase in Gagne comorbidity score (OR = 0.761; 95% CI, 0.599–0.968). Yearly between 2000 and 2010, 10.65% to 19.77% of patients received adjuvant therapy (7.143%–42.105% of those who received SRS). Although no survival benefit was seen with the addition of adjuvant therapy (P = .1236), the subgroup of patients receiving SRS had better survival compared with those receiving surgery alone (adjusted hazard ratio [aHR] = 0.544; 95% CI, 0.318–0.929). Furthermore, when stratifying patients by degree of resection, those who underwent partial or local resection and did not receive SRS had an increased risk of death compared with those who did (aHR = 1.934; 95% CI, 0.992–3.771).

CONCLUSIONS: Utilization of adjuvant XRT and SRS remained stable between 2000 and 2010. Male sex, young age, marriage, partial resection, grade II/III tumors, and large tumors predicted for use of adjuvant therapy. For all patients, SRS improved survival compared with craniotomy alone. For patients with incomplete resection, SRS improved survival compared with craniotomy alone and adjuvant XRT. Randomized, prospective clinical trials are needed to better define the role of adjuvant XRT or SRS.

Proceedings of the 97th Annual Meeting of the American Radium Society - americanradiumsociety.org