Stereotactic radiotherapy for large vestibular schwannomas: Volume change following single fraction versus hypofractionated approaches
Michael Huo, Heath Foley, Mark Pinkham, Mihir Shanker, Anne Bernard, Michael Jenkins, Sarah Olson, Bruce Hall, Trevor Watkins, Catherine Jones and Matthew Foote
Hypofractionated stereotactic radiotherapy is a treatment option for large vestibular schwannomas supported by an increasing evidence. A single-institution retrospective review of large (>3.5cc) vestibular schwannomas treated with hypofractionated stereotactic radiotherapy and single-session radiosurgery was conducted. Using serial follow up scans, a volumetric analysis of tumor volume change over time was performed. Vestibular schwannomas treated with hypofractionated stereotactic radiotherapy appeared to reduce in volume significantly faster than those treated with single-session radiosurgery. Cystic lesions reduced in volume faster than solid lesions. There was no significant difference in the rates of radiological and symptomatic oedema, nor subsequent dexamethasone requirement between the two treatment modalities.
Keywords: Vestibular schwannoma, acoustic neuroma, radiosurgery, radiotherapy, stereotactic, Gamma Knife