[18F]-DPA-714 PET/CT (Positron Emission Tomography/Computerized Tomography) in Triple Negative Breast Cancers

The purpose of this study is to evaluate the correlation of inflammation assessed by M1/M2 macrophage polarization determined by tumor immunohistochemistry analysis and \[18F\] DPA-714 PET imaging by using qualitative and image texture analysis in patients with triple negative breast cancer.

Patients receive pre-therapeutic diffusion-weighted breast MRI (Magnetic resonance imaging) and 18FDG (fluorodeoxyglucose) PET/CT (Positron Emission Tomography/Computerized Tomography) scan within 30 days before enrollment.

\[18F\] DPA-714 PET/CT scan is performed before surgery. About 3 MBq/Kg of \[18F\] DPA-714 are injected intravenously, two acquisition sequences are performed following injection and 60 minutes after injection in order to evaluate early and late tumor uptake of \[18F\] DPA-714.

Surgery is scheduled after \[18F\] DPA-714 PET/CT scan. Tissue samples from breast surgery are used to assess M1 and M2 macrophages expression and to perform tumor molecular subtyping by Immunohistochemical analysis. Tumor Autoradiography with the TSPO (18 kDa Translocator Protein) ligand \[18F\]DPA-714 will be also assessed on tumor tissue.

A blood sample is performed before \[18F\] DPA-714 PET/CT scan in order to assess the genotyping of TSPO (18 kDa Translocator Protein) gene.

\[18F\]-DPA-714 PET/CT scan

Drug: [18F]-DPA-714

\[18F\]-DPA-714

Plazo: 2 months

Intratumoral macrophages were quantified by immunohistochemistry on surgical tumor specimens. CD68-positive cells were used to quantify the total macrophage population (M1 and M2 macrophages), whereas CD163-positive cells were used to identify M2-polarized macrophages. The percentage of M2 macrophages was calculated as the proportion of CD163-positive cells among all CD68-positive macrophages.

Results are presented as the number of participants whose tumors showed a predominance of M2-polarized macrophages.

Plazo: 2 months

The correlation between the percentage of CD163-positive M2 macrophages (determined by immunohistochemistry) and tumor SUVmax on \[18F\]DPA-714 PET/CT was assessed using Spearman's rank correlation coefficient.

Plazo: 2 months

The correlation between intratumoral CD68-positive macrophage infiltration (assessed by immunohistochemistry) and tumor SUVmax on \[18F\]DPA-714 PET/CT was evaluated using Spearman's rank correlation coefficient.

Plazo: 2 months

Tumor uptake patterns were classified as above, equal to, or below muscular background and are presented descriptively according to TSPO genotype (HAB, MAB, LAB). No formal statistical analysis was performed because of the limited sample size.

Plazo: 1 month

Early tumor uptake was assessed using dynamic PET/CT time-activity curves (TACs). Results are presented as the slope of tracer accumulation derived from tumor TACs. Tumors were classified relative to the contralateral pectoral muscle as above muscular, equal to muscular, or below muscular background.

Plazo: 1 month

Primary tumor detection was assessed qualitatively using \[18F\]-DPA-714 PET/CT, 18F-FDG PET/CT, and diffusion-weighted breast MRI. Results are presented as the number of participants in whom the primary tumor was identified by each imaging modality.

Plazo: 1 month

Number of patients with adverse events and serious adverse event after \[18F\]-DPA-714 administration

Plazo: 1 month

Late tumor uptake was assessed during the plateau phase of dynamic \[18F\]-DPA-714 PET/CT time-activity curves (TACs). Tumors were classified relative to the contralateral pectoral muscle as above muscular, equal to muscular, or below muscular background. Results are presented as median SUVmean values and ranges for each uptake pattern.

Pilot Feasibility Study: Inflammation and Presence of M2 Macrophages Explorations With[18F]-DPA-714 PET/CT in Triple Negative Breast Cancers