Belmonte Beitia, Juan. Pérez García, Victor M.. Bogdanska, Magdalena. Schucht, Philippe. Bodnar, Marek. 

Low grade gliomas (LGGs) are infiltrative and incurable primary brain tumours with typically slow evolution. These tumours usually occur in young and oth- erwise healthy patients, bringing controversies in treatment planning since ag- gressive treatment may lead to undesirable side effects. Thus, for management decisions it is essential to find a method to verify tumours aggressiveness and test their response to standard therapies with the lowest toxicity possible. Here we propose a mathematical model of LGG growth and its response to chemo- therapy which agrees with available medical data. The model predicts, and our clinical data confirms, that the speed of response to chemotherapy is related to both prliferative potency of tumour and its resistance to therapy. Moreover, we provide estimated formula for time of tumour response to therapy, which can be 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 the tumour growth and further prognosis.