A practical mathematical model for glioblastomas (brain tumours), which 
incorporates the two key parameters of tumour growth, namely the cancer cell 
diffusion and the cell proliferation rate, has been shown to be clinically 
useful and predictive. Previous studies explain why multifocal recurrence is 
inevitable and show how various treatment scenarios have been incorporated in 
the model. In most tumours, it is not known when the cancer started. Based on 
patient in vivo parameters, obtained from two brain scans, it is shown how to 
estimate the time, after initial detection, when the tumour started. This is an 
input of potential importance in any future controlled clinical study of any 
connection between cell phone radiation and brain tumour incidence. It is also 
used to estimate more accurately survival times from detection. Finally, based 
on patient parameters, the solution of the model equation of the tumour growth 
helps to explain why certain patients live longer than others after similar 
treatment protocols specifically surgical resection (removal) and irradiation.