Original Article Vestibular Schwannoma Hypofractionated Stereotactic Radiation Therapy in Five Fractions

Aim: To retrospectively analyse the long-term results of hypofractionated stereotactic radiation therapy (HSRT) applied in five fractions for vestibularMaterials and methods: One hundred and thirty-four patients with vestibular schwannomas underwent medical treatment of HSRT. The median follow-up time interval was 54 months (range 6-121 months). All patients had a prescribed dose of 22 Gy in five fractions to D90. Restaging was carried out by thin-slice contrast-enhanced T1 magnetic resonance imaging. Progression was defined as 2 mm post-treatment tumour enlargement. Progression or death for any reason was counted as an event in progression-free survival rates. Acute toxicity was defined as adverse events occurring within 3 months of HSRT; long-termResults: In 74/128 patients who had >6 months of follow-up (54%), the HSRT resulted in a partial or a complete response. The mean time interval for response in 50% of these was 4 years, whereas in 49 patients (38%) vestibular schwannomas failed to show any response, resulting in stable disease. Five of 128 patients (4%) showed marked progressive vestibular schwannomas after treatment in the first 3 years; two of them received conventionally fractionated radiation therapy. Local control at 3, 5 and 7 years was 96%, 95% and 94%, respectively. Seven were lost to follow-up. The median planning target volume was 2.1 ml (range 0.78-8.66). The 3- and 5-year progression-free survival rates were 95% and 94%, respectively. Seven patients reported a marked deterioration in hearing ability. Post-radiation therapy magnetic resonance imaging showed variability in oedema collection, but no patient suffered from radio-necrosis. Grade 2 temporaryConclusion: Delivering HSRT in five fractions for vestibular schwannoma appears safe and efficient, combining both efficiency and short treatment time while (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of The Royal College of Radiologists. This is an open access article under the CC BY license (http://

Automated summary

A retrospective analysis was conducted on the long-term results of hypofractionated stereotactic radiation therapy (HSRT) for vestibular schwannomas. The majority of patients showed a positive response to HSRT, while around 38% of patients had stable disease without any response. The local control rates at 3, 5, and 7 years were 96%, 95%, and 94% respectively. Temporary grade 2 toxicity was observed in some patients, but no cases of radiation necrosis were reported.