Background: High-grade gliomas with a widespread infiltration beyond the lesion detectable on diagnostic images are increasingly treated with Gamma Knife™ Radiosurgery (GKRS). The aim of this study was to assess the cell infiltration impact on the GKRS outcome for invasive gliomas.
Materials and methods: Tumor cell distribution was predicted using a novel algorithm whose computations are iterated until they reach an agreement with histopathology results. Treatment plans with different combinations of dose prescription (20 Gy at 50%-20% isodose) and targets [Gross Tumour Volume (GTV), zone 1 with 100%-60% of the GTV cell density and zone 2 with 60%-0% of the GTV cell density] were evaluated using standard conformity indexes (CI) and radiobiological parameters.
Results: Considerable differences in terms of tumor control probability were found between plans having similar CI but different targets.
Conclusion: To account for tumor cell infiltration outside the target is of key importance in GKRS and a radiobiological evaluation should accompany well-established CI.
Keywords: Gamma Knife; glioma; modelling; tumor cell infiltration.
Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.