Biocomputing: numerical simulation of glioblastoma growth and comparison with conventional irradiation margins.
OBJECTIVE
Estimation of glioblastoma (GBM) growth patterns is of tremendous value in determining tumour margins for radiotherapy. We have previously developed a numerical simulation model for the pattern of spread of glioblastoma tumours. This model involved the creation of a digital atlas of the brain with elasticity and resistance-to-invasion values for specific brain structures and also included probable direction of tumour spread as estimated by Diffusion Tensor Imaging (DTI). The current study is aimed at comparing the outcome of such simulation with conventional irradiation margins currently in use.


METHODS
Actual patient data were used to simulate the direction of microscopic extension, using a variety of margin-, proliferation- and diffusion-rate scenarios to generate growth patterns, which were then compared with current standard radiotherapy margins.


RESULTS
Our patient growth pattern simulations showed microscopic invasion beyond irradiation margins for both combinations of high-diffusion/low-proliferation and low-diffusion/high-proliferation rate scenarios. The model also indicated that some healthy brain tissue that was projected to be safe from recurrence fell inside treatment margins.


CONCLUSIONS
These results may explain the current inadequacy of our treatment techniques in preventing locoregional recurrences of GBM.
Département de Radiothérapie, Centre Antoine, Nice, France. pierre-yves.bondiau@cal.nice.fnclcc.fr
Pierre-Yves
PY
Bondiau
Ender
E
Konukoglu
Olivier
O
Clatz
Herve
H
Delingette
Marc
M
Frenay
Philippe
P
Paquis
D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000532:radiotherapy; D049109:Cell Proliferation / Q000528:radiation effects; D004058:Diffusion; D005909:Glioblastoma / Q000175:diagnosis / Q000473:pathology* / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008954:Models, Biological; D009361:Neoplasm Invasiveness; D047368:Tumor Burden