Chia-An Wu, Huai-Che Yang, Yong-Sin Hu, Hsiu-Mei Wu, Chung-Jung Lin, Chao-Bao Luo, Wan-Yuo Guo, Cheng-Chia Lee, Kang-Du Liu and Wen-Yuh Chung
Gamma Knife surgery (GKS) obliterates 65%–87% of cavernous sinus dural arteriovenous fistulas (CSDAVFs). However, the hemodynamic effect on GKS outcomes is relatively unknown. The authors thus used the classification scheme developed by Suh et al. to explore this effect.
The authors retrospectively (1993–2016) included 123 patients with CSDAVFs who received GKS alone at the institute and classified them as proliferative type (PT; n = 23), restrictive type (RT; n = 61), or late restrictive type (LRT; n = 39) after analyzing their pre-GKS angiography images. Treatment parameters, the presence of numerous arterial feeders, and venous drainage numbers were compared across the CSDAVF types. Patients’ follow-up MR images were evaluated for the presence of complete obliteration. A Kaplan-Meier analysis was conducted to determine the correlation between CSDAVF types and outcomes.
The 36-month probability of complete obliteration was 74.3% for all patients, with no significant differences across types (p = 0.56). PT had the largest radiation volume (6.5 cm3, p < 0.001), the most isocenters (5, p = 0.015) and venous drainage routes (3, p < 0.001), and the lowest peripheral dose (16.6 Gy, p = 0.011) and isodose level coverage (64.3%, p = 0.006). CSDAVFs presenting with ocular patterns were less likely to be completely obliterated (hazard ratio 0.531, p = 0.009). After adjustment for age, CSDAVFs with more venous drainage routes were less likely to be completely obliterated (hazard ratio 0.784, p = 0.039).
GKS is an equally effective treatment option for all 3 CSDAVF types. Furthermore, the number of venous drainage routes may help in predicting treatment outcomes and making therapeutic decisions.
Cheng-Chia Lee, Sanford P. C. Hsu, Chung-Jung Lin, Hsiu-Mei Wu, Yu-Wei Chen, Yung-Hung Luo, Chi-Lu Chiang, Yong-Sin Hu, Wen-Yuh Chung, Cheng-Ying Shiau, Wan-Yuo Guo, David Hung-Chi Pan and Huai-Che Yang
The presence of epidermal growth factor receptor (EGFR) mutations in non–small cell lung cancer (NSCLC) has been associated with elevated radiosensitivity in vitro. However, results from clinical studies on radiosensitivity in cases of NSCLC with EGFR mutations are inconclusive. This paper presents a retrospective analysis of patients with NSCLC who underwent regular follow-up imaging after radiotherapy for brain metastases (BMs). The authors also investigated the influence of EGFR mutations on the efficacy of Gamma Knife radiosurgery (GKRS).
This study included 264 patients (1069 BMs) who underwent GKRS treatment and for whom EGFR mutation status, demographics, performance status, and tumor characteristics were available. Radiological images were obtained at 3 months after GKRS and at 3-month intervals thereafter. Kaplan-Meier plots and Cox regression analysis were used to correlate EGFR mutation status and other clinical features with tumor control and overall survival.
The tumor control rates and overall 12-month survival rates were 87.8% and 65.5%, respectively. Tumor control rates in the EGFR mutant group versus the EGFR wild-type group were 90.5% versus 79.4% at 12 months and 75.0% versus 24.5% at 24 months. During the 2-year follow-up period after SRS, the intracranial response rate in the EGFR mutant group was approximately 3-fold higher than that in the wild-type group (p < 0.001). Cox regression multivariate analysis identified EGFR mutation status, extracranial metastasis, primary tumor control, and prescribed margin dose as predictors of tumor control (p = 0.004, p < 0.001, p = 0.004, and p = 0.026, respectively). Treatment with a combination of GKRS and tyrosine kinase inhibitors (TKIs) was the most important predictor of overall survival (p < 0.001).
The current study demonstrated that, among patients with NSCLC-BMs, EGFR mutations were independent prognostic factors of tumor control. It was also determined that a combination of GKRS and TKI had the most pronounced effect on prolonging survival after SRS. In select patient groups, treatment with SRS in conjunction with EGFR-TKIs provided effective tumor control for NSCLC-BMs.