Extra- and intracranial schwannomas treated with fractionated stereotactic irradiation: Results of a retrospective, multicentric study.

PURPOSE: Limited data exist on the role of fractionated stereotactic radiotherapy in the therapeutic strategy for neurinomas, particularly for extracranial locations. The objective of this study was to describe intra- and extracranial schwannomas using stereotactic body radiotherapy.

MATERIALS AND

METHODS

A multicentric, non-interventional study was conducted using retrospectively collected data between January 2007 and September 2021. Patients who received fractionated stereotactic radiotherapy were included. Patient characteristics, data on localization, acute and chronic toxicity, local control, as well as progressive-free survival were collected.

RESULTS

A total of 72 patients were included with 17 being treated with surgery beforehand. Intracranial localizations concerned nerve VIII (36 lesions), but also nerve IV, V, X and mixed nerves (XII). Extracranial localizations could be cervical, thoracic or lumbar. Treatment regimens were mainly delivering 36Gy in nine fractions of 4Gy (23.6 %) and 21Gy in three fractions of 7Gy (48.6 %). The median follow-up was 49.2 months. Local control was 84.8 % at 3 and 81.8 % at 5 years. Localization and dose schedule did not affect local control (P=0.67 and P=0.46 respectively). Besides surgery, no other factors were associated with local control (P=0.01). Two patients (5.0 %) experienced improvement in their hearing symptoms, while 35 (87.5 %) remained stable.

CONCLUSION

Our large multicentre study results add to evidence that fractionated stereotactic radiotherapy is a safe and effective treatment option for managing intracranial schwannomas but also extracranial localizations, including those of larger sizes.