Ms-18 * Predictors of Response and Adverse Events for Meningiomas Managed With Gamma Knife Radiosurgery
Year: 2014
Type: conference-abstract
Abstract: OBJECTIVE: To identify clinical, radiological, and dosimetric predictors of meningioma response to stereotactic radiosurgery (SRS), and post-SRS adverse radiation events (ARE). METHODS: A retrospective review of the database of meningioma patients treated with SRS between December 2005 and June 2013 at the University Health Network was performed. Seventy-five patients had at least 24 months of clinical and radiological follow-up, and were therefore included in this study. Tumor growth rates were calculated using the Specific Growth Rate (SGR). Tumor control was defined as any volumetric/diametric change less than +10%. Volumetric measurements were made using T1-Gadolinium enhanced 3T MRI scans with ITK-SNAP2.2 software. Univariate statistics were used to identify predictors of post SRS AREs. All statistical analyses were performed using IBM SPSS v20.0. RESULTS: The majority of patients (69.3%) were females and mean age at treatment was 58.6 years. Patients were followed up for a median time of 36.2 months. Twenty-one patients had undergone prior surgical resection. One patient required salvage surgical intervention following SRS. Volumetric tumor control (52%) was inferior to diametric control (92%). Twenty-six patients (34.6%) experienced some form of new-onset complication after SRS: Headache (17.3%), cranial neuropathy (10.6%), speech impairment (2.7%), tremor (2.7%), and ataxia (1.3%). Patients with meningiomas that had a growth rates of more than 10%/year were more likely to have long-term headache after SRS (p = 0.022). Fourteen patients (18.7%) experienced new onset T2 signal change signifying of edema; eight of these patients were symptomatic. Lower Conformity index (1.24 vs. 1.4), and higher treatment-volume ratio (TVR) (0.80 vs. 0.72) were significantly associated with development of edema after SRS (p<0.05, power > 0.8). CONCLUSION: Volume-based reporting of SRS outcomes for meningiomas is more accurate for reporting tumor control. Conformity index and TVR were identified as predictors of edema following radiosurgery.
Source: Neuro-Oncology
Authors: A. Mansouri, S. Larjani, G. Klironomos, G. Zadeh
Institutions: University of Toronto, Toronto Western Hospital
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2322333567