Multiparametric MRI to evaluate the anti-inflammatory effect of a non-steroideal drug in the tumoral development of a glioma rat model

Trabajo presentado en el ESMRMB 38th Annual Scientific Meeting, celebrado en modalidad virtual del 07 al 09 de octubre de 2021.[Introduction]: Glioblastoma multiforme (GBM) is the most aggressive manifestation of brain tumors [1]. The prognosis and survival remain poor and tumors generally recur after standard surgery and co-adjuvant radio-chemotherapy [2]. Many studies have been done with GBM models, identifying magnetic resonance imaging (MRI) parameters to be used as non-invasive surrogate biomarkers of this pathology [3], which are able to determine the therapeutic response during the initial stages of treatment or even before. Anti-inflammatory (AI) agents have been studied as anti-tumoral drugs [4] and tested in GBM models with promising results [5]. Furthermore, the modulation of inflammation in GBM by AIs may improve responses to current treatments [6] [7]. In this study we aimed to assess the MRI tumor features evolution in GBM-bearing rats treated with a non-steroidal AI to investigate its impact on the evolution and treatment of the disease. [Methods]: GBM was induced in Sprague-Dawley rats by intracranial injection of C6 cells [8]. Animals were subcutaneously (s.c). injected with the AI drug Meloxicam (2 mg/kg) or saline (control) during 15 days, starting the treatment 5 days after tumor cell injection. MRI evaluations were carried out in a 7T system until day 27 post-cell injection (or until end-point criteria). Tumor volume was followed-up with Gd-T1W images at different time points. Multiparametric MRI studies with magnetization transfer, diffusion-weighted, T2W, T2*W and dynamic contrast enhancement images were acquired at an early and an advanced tumor stage. Parametric maps were generated with home-made software developed with Matlab. [Results]: So far, we have observed lower MTR% and axial diffusivity (AD) values in the tumor area of treated rats compared with control rats at the advanced tumor stage (Fig. 1), while fractional anisotropy (FA) values were higher in the peritumoral region. [Discussion]: These results could suggest that treated animals presented a greater structural integrity of the tumor tissue, which means the absence of characteristic necrosis of a developing cancer, while in the peritumoral region there was not so much accumulation of cells that would occur in an proliferation process, pointing Meloxicam as potential candidate therapy against GBM