Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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Outcome analyses for patients with gastroenteropancreatic neuroendocrine tumors (GEP NET) after peptide receptor radionuclide therapy (PRRT) are still limited, especially with regard to the impact of the Ki-67 index. Using a single-center analysis, we aimed to establish predictors of survival. ⋯ The results of this study demonstrated the favorable response and long-term outcome of patients with G1/G2 GEP NET after PRRT. Independent predictors of survival were the Ki-67 index, the patient's performance status (Karnofsky performance scale score), the tumor burden, and the baseline neuron-specific enolase level. Even patients with a Ki-67 index of greater than 10% seemed to benefit from PRRT, with a good response and a notable long-term outcome. We present the first evidence, to our knowledge, that even in patients with metastatic disease the distinction between G1 and G2-in particular, between G1 (Ki-67 index of 1%-2%) and low-range G2 (Ki-67 index of 3%-10%)-provides prognostic stratification.
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Antimicrobial peptides such as ubiquicidin (UBI) are believed to differentiate between mammalian and bacterial or fungal cells. (99m)Tc-UBI29-41 was previously tested for detecting infection in humans using SPECT. For the present study, the UBI fragment UBI29-41 (TGRAKRRMQYNRR) was conjugated to 1,4,7-triazacyclononane-triacetic acid (NOTA), radiolabeled with (68)Ga, and investigated in a rabbit infection model. ⋯ (68)Ga-NOTA-UBI29-41 was strongly localized in bacteria-infected areas and minimally detected in a sterile inflammation area in rabbit muscles. The findings propose this compound to be an excellent first-line PET/CT tracer to allow the distinguishing of infection from inflammation.