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Background The long-term outcomes of CyberKnife-based hypofractionated stereotactic radiotherapy (SRT) for intra/ extracranial non-vestibular schwannomas (nVS) need to be accumulated. Method Patients who received SRT by CyberKnife for nVS from 2010 to 2019 were retrospectively reviewed. Results A total of 45 patients with nVS were identified. The mean age was 53 (± 18) years old, and 23 patients (51%) were female. Twenty-nine patients (64%) had previous procedures. As for the tumor extension, 22 (49%) nVS were classified as primary intracranial, five (11%) were classified as intra/ extracranial (dumbbell shape), and 18 (40%) were classified as primary extracranial. The median prescribed dose, covering 95% of the planning target volume, was 21 (IQR 21 – 25) Gy, and the median target volume was 7 (IQR 3.6-13.1) cm3. The local control rate of nVS for patients without neurofibromatosis type 2 (NF2) was 100%. Old age (OR 0.92, p-value 0.03) and previous surgery (OR 0.02, p-value 0.02) were significant risk factors for no symptomatic improvement. The progression-free survival was 74 (±33) months clinically and 69 (IQR 36 – 94) months radiologically. During follow-up, two cases (4%) with NF2 resulted in treatment failure, 13 cases (41%) resulted in transient tumor expansion (TTE), 10 (22%) suffered from transient adverse radiation effect (ARE), and two (4%) resulted in permanent ARE. Conclusions Hypofractionated SRT for head, neck, and spine nVS was an effective treatment regardless of tumor extension relative to the cranium. Although the risk of permanent ARE was low, some patients experienced transient clinical worsening due to TTE.

Few reports exist demonstrating the effects of CyberKnife radiotherapy (CKRT) on the central skull base meningiomas (CSMs). Retrospective analysis of 113 patients were performed. The median age was 62 (IQR 50 – 72) years old, and 78 patients (69%) were female. Upfront CKRT was performed in 41 (36%), where 17 (15%) patients were asymptomatic. The other CKRT was for postoperative adjuvant therapy in 32 (28%), and for the recurrent or relapsed tumors in 40 (35%) patients. Previous operation was done in 74 patients (66%). Among the available pathology in 46 patients, 37 (80%) were WHO grade I, 8 (17%) were grade II, and 1 (2%) were grade III. The median prescribed dose covered 95% of the planning target volume was 2500 (IQR 2100 – 2500) cGy and the median target volume was 9.5 (IQR 3.9 – 16.9) cm3. The median PFS was 48 (IQR 23 – 73) months and 84% and 78% were free of tumor progression at five, and 10 years respectively. The median follow-up was 49 (IQR 28 – 83) months. PFS was better in grade I than grade II (p = 0.02). No other baseline factors including the history of previous operation was associated with PD or PFS. Adverse events of radiation therapy were radiation- induced optic neuropathy (0.9%), and cerebral edema (4.4%). Asymptomatic cavernous carotid stenosis was found in three (2.7%), five (4.4%) underwent ventriculoperitoneal shunt placement for normal pressure hydrocephalus, and five (4.4%) died. CKRT is useful for the management of CSMs with low rate of adverse events.

IntroductionTo analyze the long-term follow-up data of CyberKnife treatment (CKT) for head and neck paragangliomas (HNPGs). MethodsPatients who received CKT to HNPGs from 2010 to 2019 were retrospectively reviewed. ResultsA total of 34 HNPGs from 29 patients were identified. The mean age was 50 (± 16) years old, and 15 patients (52%) were female. Previous operation was done in 15 patients (55%). Four cases (14%) were functional in hormone production. According to Fisch classification, one case (3%) was B, 12 (42%) were C, 14 (48%) were D, and two cases (7%) were out of classification. The median prescribed dose covered 95% of the planning target volume was 2500 (IQR 2100 – 2600) cGy and the median target volume was 10 (IQR 5.8 – 21.3) cm3. The local control rate was 97%. The median progression-free survival was 66 (IQR 27.5 – 95.0) months and 93.8%, and 91.7% were free of tumor progression at five, and seven years respectively. During the follow-up, one case (3%) resulted in permanent facial nerve palsy (CTCAE 1, House-Brackmann grade II), and another case (3%) resulted in asymptomatic cerebellar radiation necrosis. Univariate and multivariate analysis showed no previous surgical history (OR 10.3, 95% CI 1.5 – 69.3, p = 0.02) was a positive predictor of symptom improvement. We devised a treatment flow-chart based on our finding. ConclusionsCKT for HNPGs was an effective treatment with little side effect over the long term and should be considered the first-line therapy for symptomatic nonfunctional HNPGs for better symptom control.