@article {374, title = {Combined stereotactic biopsy and stepping-source interstitial irradiation of unresectable glioblastoma multiforme.}, journal = {J Neurosurg Sci}, year = {2016}, month = {2016 Jan 15}, 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.

}, issn = {0390-5616}, author = {Brehmer, Stefanie and Guthier, Christian V and Clausen, Sven and Schneider, Frank and Schulte, Dirk M and Benker, Matthias and Bludau, Frederic and Glatting, Gerhard and Marx, Alexander and Schmiedek, Peter and Hesser, J{\"u}rgen and Wenz, Frederik and Giordano, Frank A} }