{Reference Type}: Journal Article
{Title}: Pilot Feasibility Study: 18 F-DPA-714 PET/CT Macrophage Imaging in Triple-Negative Breast Cancers (EITHICS).
{Author}: Rousseau C;Metz R;Kerdraon O;Ouldamer L;Boiffard F;Renaudeau K;Ferrer L;Vercouillie J;Doutriaux-Dumoulin I;Mouton A;Le Thiec M;Morel A;Rusu D;Santiago-Ribeiro MJ;Campion L;Arlicot N;Kraeber-Bodéré F;
{Journal}: Clin Nucl Med
{Volume}: 49
{Issue}: 8
{Year}: 2024 Aug 1
{Factor}: 10.782
{DOI}: 10.1097/RLU.0000000000005338
{Abstract}: <B>UNASSIGNED: </B>Tumor-associated macrophages are targets of interest in triple-negative breast cancer (TNBC). The translocator protein 18 kDa (TSPO) is a sensitive marker for macrophages and holds potential relevance in TNBC stratification. This pilot prospective study (EITHICS, NCT04320030) aimed to assess the potential of TSPO PET/CT imaging using 18 F-DPA-714 in primary TNBC, compared with immunohistochemistry, autoradiography, and TSPO polymorphism.<BR><B>METHODS: </B>Thirteen TNBC patients were included. They underwent TSPO genotyping (HAB, MAB, LAB), 18 F-FDG PET/CT, and breast MRI. Semiquantitative PET parameters were computed. VOIs were defined on the tumor lesion, healthy breast tissue, and pectoral muscle to obtain SUV, tumor-to-background ratio (TBR), and time-activity curves (TACs). Additionally, immunohistochemistry, 3 H-DPA-714, and 3 H-PK-11195 autoradiography were conducted.<BR><B>RESULTS: </B>The majority of TNBC tumors (11/13, 84%) had a preponderance of M2-polarized macrophages with a median proportion of 82% (range, 44%-94%). 18 F-DPA-714 PET/CT clearly identified TNBC tumors with an excellent TBR. Three distinct patterns of 18 F-DPA-714 TACs were identified, categorized as "above muscular," "equal to muscular," and "below muscular" with reference to the muscular background. For the "above muscular" group (2 HAB and 2 MAB), "equal muscular" group (3 HAB, 3 MAB, and 1 LAB), and "below muscular" group (1 LAB and 1 MAB), tumor TACs showed a 18 F-DPA-714 accumulation slope of 1.35, 0.62, and 0.22, respectively, and a median SUV mean of 4.02 (2.09-5.31), 1.66 (0.93-3.07), and 0.61 (0.43-1.02).<BR><B>CONCLUSIONS: </B>This study successfully demonstrated TNBC tumor targeting by 18 F-DPA-714 with an excellent TBR, allowing to stratify 3 patterns of uptake potentially influenced by the TSPO polymorphism status. Further studies in larger populations should be performed to evaluate the prognostic value of this new biomarker.