  Low grade gliomas (LGGs) are infiltrative and incurable primary brain tumours
with typically slow evolution. These tumours usually occur in young and
otherwise healthy patients, bringing controversies in treatment planning since
aggressive treatment may lead to undesirable side effects. Thus, for management
decisions it would be valuable to obtain early estimates of LGG growth
potential. Here we propose a simple mathematical model of LGG growth and its
response to chemotherapy which allows the growth of LGGs to be described in
real patients. The model predicts, and our clinical data confirms, that the
speed of response to chemotherapy is related to tumour aggressiveness.
Moreover, we provide a formula for the time to radiological progression, which
can be possibly used as a measure of tumour aggressiveness. Finally, we suggest
that the response to a few chemotherapy cycles upon diagnosis might be used to
predict tumour growth and to guide therapeutical actions on the basis of the
findings.
