RESUMO
PURPOSE: The aim of this retrospective study was to evaluate the use of [68Ga]Ga-PSMA PET/CT in therapy response assessment (TRA) of mCRPC patients treated with [177Lu]Lu-PSMA-617 and its correlation with overall survival (OS). METHODS: Thirty-nine patients were included in the study. Patient-/lesion-based early and late response assessment (ERA/LRA) was defined as PET2 (after two therapy cycles) vs. PET1 (before the first cycle) (n = 29) and end of treatment PET vs. PET1 (n = 17), respectively. PET-based response (PET parameters; modified (m) PERCIST/EORTC), biochemical response (ΔPSA; category-based) and category-based clinical response (CRA) was tested for correlation/agreement. PET-based TRA was correlated with OS. RESULTS: A significant correlation/agreement was shown between PET parameters and CRA as well as biochemical response in LRA of all lesions and between mPERCIST-based and category-based PSA response assessment in LRA (bone lesion-based, P = 0.045, κ = 0.184). At ERA, OS was significantly higher in CR/PR/SD compared to progressive disease applying mPERCIST/EORTC criteria (P = 0.0024). CONCLUSION: In [177Lu]Lu-PSMA-617-treated mCRPC patients OS of the group of CR/PR/SD was significantly higher compared to the progressive disease group (mPERCIST/EORTC) in ERA. Therefore, [68Ga]Ga-PSMA PET might serve as a complementary diagnostic tool for TRA offering prognostic value regarding OS.
Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia ComputadorizadaRESUMO
Angiogenesis plays a central role in the healing process following acute myocardial infarction. The PET tracer [68Ga]-NODAGA-RGD, which is a ligand for the αvß3 integrin, has been investigated for imaging angiogenesis in the process of healing myocardium in both animal and clinical studies. It´s value as a prognostic marker of functional outcome remains unclear. Therefore, the aim of this work was to establish [68Ga]-NODAGA-RGD for imaging angiogenesis in the murine infarct model and evaluate the tracer as a predictor for cardiac remodeling in the context of cardiac stem cell therapy. [68Ga]-NODAGA-RGD PET performed seven days after left anterior descending coronary artery (LAD) occlusion in 129S6 mice showed intense tracer accumulation within the infarct region. The specificity was shown in a sub-group of animals by application of the competitive inhibitor cilengitide prior to tracer injection in a subgroup of animals. Myocardial infarction (MI) significantly reduced cardiac function and resulted in pronounced left ventricular remodeling after three weeks, as measured by cardiac MRI in a separate group. Cardiac induced cells (CiC) that were derived from mESC injected intramyocardially in the therapy group significantly improved left ventricular ejection fraction (LVEF). Surprisingly, CiC transplantation resulted in significantly lower tracer accumulation seven days after MI induction. Accordingly, we successfully established the PET tracer [68Ga]-NODAGA-RGD for the assessment of αvß3 integrin expression in the healing process after MI in the mouse model. Yet, our results indicate that the mere extent of angiogenesis following MI does not serve as a sufficient prognostic marker for functional outcome.