Combined stereotactic biopsy and stepping-source interstitial irradiation of unresectable glioblastoma multiforme.

TitleCombined stereotactic biopsy and stepping-source interstitial irradiation of unresectable glioblastoma multiforme.
Publication TypeJournal Article
Year of Publication2016
AuthorsBrehmer, S, Guthier, CV, Clausen, S, Schneider, F, Schulte, DM, Benker, M, Bludau, F, Glatting, G, Marx, A, Schmiedek, P, Hesser, J, Wenz, F, Giordano, FA
JournalJ Neurosurg Sci
Date Published2016 Jan 15
ISSN0390-5616
Abstract

Patients diagnosed with glioblastoma multiforme receiving stereotactic biopsy only either due to tumor localization or impaired clinical status face a devastating prognosis with very short survival times. One strategy to provide an initial cytoreductive and palliative therapy at the time of the stereotactic biopsy is interstitial irradiation through the pre-defined trajectory of the biopsy channel. We designed a novel treatment planning system and evaluated the treatment potential of a fixed-source and a stepping-source algorithm for interstitial radiosurgery on non-spherical glioblastoma in direct adjacency to risk structures. Using both setups, we show that radiation doses delivered to 100% of the gross tumor volume shifts from sub-therapeutic (10-12 Gy) to sterilizing single doses (25-30 Gy) when using the stepping source algorithm due to improved sparing of organs-at-risk. Specifically, the maximum doses at the brain stem were 100% of the PTV dose when a fixed central source and 38% when a stepping-source algorithm was used. We also demonstrated precision of intracranial target points and stability of superficial and deep trajectories using both a phantom and a body donor study. Our setup now for the first time provides a basis for a clinical proof-of-concept trial and may widen palliation options for patients with limited life expectancy that should not undergo time-consuming therapies.

Alternate JournalJ Neurosurg Sci
Citation Key374