Neuroendocrine tumors are a quite rare category of tumors, corresponding to about the 0.5% of total malignant tumors. They origin from neuroendocrine system’s cell, which are widely diffused in the organism. In the last decades, the number of diagnosed NET registered a significant increase partly due to the improvement on imaging technologies, including Computed Tomography and Positron Emission Tomography. The thesis is focused on PET images analysis related to 68Ga-DOTATOC radiopharmaceutical, a recetptor tracer analogous to somatostain. The aim of the elaborate consists in the extraction of textural parameters from PET images, in the evaluation of their robustness, and the identification, among them, those that are more related to Ki67.