Applicazione della tecnica perfusione MRI nella valutazione del grado di malignità dei gliomi cerebrali

In the cerebral gliomas clinical practice, correct grading is really important. Establishing the correct lesion’s malignancy degree has relevant clinical implications, in terms of outcome and therapeutic strategies. Histopathologicalogical evaluation of cerebral gliomas sometime is difficult because of the impossibility of surgery or sampling mistakes, and imaging study with Magnetic Resonance provides morphological important information, but not so reliable for malignancy. During last years, there has been a considerable development of advanced RM techniques, which completes anatomy information, providing precious indications about the functionality of the investigated lesions. Perfusion represents the direct measure of the microvascularization of a tissue and can be used as a marker of imaging to estimate the tumor angiogenesis and the degree of malignancy. Our work aimed at evaluating the role of MR perfusion in establishing the correct grade of cerebral gliomas: we analysed perfusion maps of 22 patients affected by low grade or high grade gliomas, with or without histological confirmation, and after that we compared among tumor degrees II, III, IV and between simplified grade (low grade gliomas and high grade gliomas) with the main parameters of perfusion CBV (Cerbral Blood Volume) e CBF (Cerebral Blood Flow). A positive correlation has been found out between the two parameters and between the parameters and the cancer degree and this means that the bigger the degree of malignancy, the greater the perfusion is. This agrees with the histological datum that shows that the more consistent the vascularization, the more malignant the lesion is. It has been possible distinguishing between high grade gliomas and low grade gliomas throw the perfusion parameters, but it has not been possible to make a distinction between II/III and III/IV, because of the low number of patients suffering from grade III gliomas. Therefore, perfusion MR study might represent a useful instrument for the differential diagnosis between HGG and LGG, with relevant implications in the follow-up too. It’s still necessary to evaluate the discriminating power of the technique in the intermediate grade tumor.