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Purpose: To identify dosimetric predictive factors of facial nerve paralysis for patients with vestibular schwannomas (VS) treated in a single institution with Cyberknife® (CK) hypofractionated stereotactic radiotherapy (SRT)., Methods and Materials: Eighty-eight patients were treated from 2010 to 2020. Different treatment schedules were used over that period, some prescribed to the 80% isodose line (4 × 5 Gy, 3 × 7 Gy, 3 × 8 Gy and 5 × 5 Gy) and one to the 70% isodose line (3 × 7.7 Gy). Local control tumor and facial nerve toxicity were recorded, as well as various dosimetric indicators., Results: Median follow-up 37 months (range, 7-96). Of the 88 stereotactic treatments, 20 patients (23%) developed objectively diagnosed radiation-induced facial nerve paralysis. The 2-year and 5-year local tumor control were respectively 95% and 88%, and the overall 2-year facial nerve preservation was 76%. Prescriptions with a maximum dose point (Dmax) of 33 Gy were at a substantially higher risk of facial paralysis than prescriptions with a Dmax less than or equal to 30 Gy (HR = 4.51, 95% CI = [1.04;19.6], p = 0.045). The 2-years cumulative incidences of facial paralysis were 32% [20%;44%] in the case of a 33 Gy Dmax, against 7% [1%;21%] otherwise. We identified four significative dosimetric predictive factors for radiation-induced facial nerve dysfunction: a GTV minimal dose over 22 Gy (EQD2 = 45.5 Gy, p = 0.019), a GTV mean dose over 29 Gy (EQD2 = 73.5 Gy, HR = 2.84, 95% CI = [1.10;7.36], p = 0.024), a PTV mean dose over 27 Gy (EQD2 = 64.8 Gy, HR = 10.52, 95% CI = [1.39;79.76], p = 0.002) and a PTV maximal dose of 32 Gy (EQD2 = 87.5 Gy,HR = 5.09, 95% CI = [1.17;22.15], p = 0.013)., Conclusion: We identified four dosimetric predictive factors for post-treatment facial paralysis. Increasing the doses of hypofractionated stereotactic radiotherapy for vestibular schwannomas leads to higher facial nerve toxicity and may lead to lower local control rates than other published series. Our three-hypofractionated regimens may have also played a role in these results., (Copyright © 2023 Elsevier B.V. All rights reserved.)

We evaluated efficacy and tolerance of hypofractionated stereotactic radiation treatment (hFSRT) in the management of intracranial meningiomas. Between December 2008 and June 2016, 126 patients with 136 intracranial meningiomas were treated with robotic hFSRT. hFSRT was performed as primary irradiation and as a salvage option for the local recurrence after prior radiotherapy. The median prescription dose was 25 Gy (12-40) with a median number of fractions of 5 (3-10). After a median follow-up of 20.3 months (range 1-77 months), the 24-months local control (LC) rate was 81% in the primary hFSRT group and 39% after hFSRT in the re-irradiation group (p=0.002). The clinical control rate of symptoms in the overall population was 95% (95% CI: 89-98%). Progression-free survival (PFS) in the overall population at 24 months was 70% (95% CI: 60%-79%). In the primary hFSRT group, PFS was significantly lower with the most hypofractionated schedules of 21-23 Gy in 3 fractions vs. 25-40 Gy in 5-10 fractions: 62% vs. 92% (p = 0.0006). The incidence of radionecrosis at 24 months was significantly lower in the primary hFSRT group, at 2% vs. 20% in the re-irradiation hFSRT group (p = 0.002).

Cerebral arteriovenous malformations (AVMs) are rare vascular lesions potentially responsible for substantial neurological morbidity and mortality. Over the past four decades, radiosurgery has become a valid therapeutic option for many patients with small intracranial AVMs, but reports describing the use of robotic stereotactic radiosurgery (SRS) are rare. The purposes of this study are to describe the efficacy and toxicity of robotic SRS for AVMs and to review the literature. The reports of 48 consecutive patients treated with SRS were reviewed. A total dose of 18 Gy in a single fraction was prescribed to the 70% isodose line. Efficacy (i.e., total obliteration of the AVM) and toxicity were analyzed. Literature search was performed on Embase and PubMed for the terms "Radiosurgery and AVMs", "Cyberknife and AVMs" and "Radiation therapy and AVMs." The median follow-up was 41 months. The median AVM volume was 2.62 cm 3 . The incidence of obliteration was 59% at 3 years. Regarding toxicity, 92% of patients remained symptom-free, 66% developed radiogenic edema on MRI, and none developed radionecrosis. Forty-one patients (85%) had embolization prior to SRS. Our study was incorporated in an exhaustive review of 25 trials categorized by SRS technique. In this review, the median follow-up was 60 months. The median nidus volume was 2 cm 3 . The median overall obliteration rate for SRS was 68% (range 36 to 92). The median embolization rate prior to SRS was 31% (range 8.23 to 90). Compared to other studies, tolerability was excellent and the obliteration rate was acceptable but probably affected by the high embolization rate prior to radiosurgery. Our study suggests that a higher dose is feasible. A larger cohort with a longer follow-up period will be needed to confirm the safety and effectiveness, and subsequently validate different prognosis and predictive scores with this treatment modality to maximize the benefits of this technology for selected patients in the long term.

Purpose: Fractionated stereotactic radiotherapy (FSR) is a recognized treatment for vestibular schwannomas (VS). This study's aim is to present clinical outcomes and local control (LC) results for patients with VS treated with FSR using the Cyberknife® (CK) in 2 French cancer centers., Methods: Patients treated with FSR for VS between 2007 and 2012 were retrospectively analyzed. Local control was determined using follow-up MRI. The hearing preservation (HP) rate was determined by analyzing pretreatment and posttreatment audiograms., Results: Forty patients were treated for VS with the CK in both centers. The mean maximal VS dimension was 18.3 mm (range 3-30). The median follow-up was 36 months and the LC was 97% at 3 years of follow-up and 89% after 5 years. The HP rate was 83% and no facial nerve impairment was reported., Conclusions: Our results in terms of LC and HP rate are congruent with similar studies that use the CK to treat VS. It appears that the CK is safe and efficient in VS management even for large lesions. Further studies with larger cohorts are warranted.

Stereotactic radiotherapy is a very high precision procedure, which has been limited to radiosurgery for a long time. Technological improvements allowed the development of radiotherapy in stereotactic conditions, leading to a lot of innovations. Previously indicated for cerebral pathologies, this procedure is now developed for extracerebral locations. In paediatrics, stereotactic radiotherapy is still limited, delivered precociously, due to the possibility of long-term late effects that needs to be addressed. This review reports the different useful conditions, technical evolutions, and the current validated paediatric indications, with differences from adults, and future directions., (Copyright © 2012 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.)

Stereotactical radiotherapy is a very high precision procedure, limited to radiosurgery since a long time. Technologic progress permitted to develop radiotherapy in stereotactical conditions, leading to a lot of innovations. Previously indicated for cerebral pathologies, this procedure is now developed for extracerebral locations. In pediatrics, stereotactical radiotherapy is still limited, delivered precociously, due to the possibility of long-term late effects that needs to be to addressed. This review reports the different useful conditions, technical evolutions, and the current validated pediatric indications, with differences from adults, and future directions. Current state of pediatric stereotactical radiotherapy used in France is presented.

Abstract: Stereotactical radiotherapy is a very high precision procedure, limited to radiosurgery since a long time. Technologic progress permitted to develop radiotherapy in stereotactical conditions, leading to a lot of innovations. Previously indicated for cerebral pathologies, this procedure is now developed for extracerebral locations. In pediatrics, stereotactical radiotherapy is still limited, delivered precociously, due to the possibility of long-term late effects that needs to be to addressed. This review reports the different useful conditions, technical evolutions, and the current validated pediatric indications, with differences from adults, and future directions. Current state of pediatric stereotactical radiotherapy used in France is presented. [Copyright &y& Elsevier]

Abstract: Stereotactic radiotherapy is a very high precision procedure, which has been limited to radiosurgery for a long time. Technological improvements allowed the development of radiotherapy in stereotactic conditions, leading to a lot of innovations. Previously indicated for cerebral pathologies, this procedure is now developed for extracerebral locations. In paediatrics, stereotactic radiotherapy is still limited, delivered precociously, due to the possibility of long-term late effects that needs to be addressed. This review reports the different useful conditions, technical evolutions, and the current validated paediatric indications, with differences from adults, and future directions. [Copyright &y& Elsevier]