Clinical evaluation of kit based Tc-99m-HYNIC-RGD2 for imaging angiogenesis in breast carcinoma patients

Abstract

Background Radiolabeled RGD peptide can be used for noninvasive in vivo imaging of αvβ3 integrin receptors leading to early detection of tumor cells and hence improving the clinical outcomes. In the present study single vial kit based HYNIC RGD2 was radiolabeled with Tc-99m and evaluated in patients with breast carcinoma. Methods Radiolabeling was performed via bifunctional chelator method. Tc-99m 1110–2960 MBq (30–80 mCi) was added to the HYNIC-RGD2 vial. The reaction mixture was heated for 20 minutes at 100°C. After performing the quality checks, whole-body planar imaging was performed in 20 patients at 2–2.5 h post i.v. injection of 555–740 MBq (15–20 mCi) of the radiotracer. Results Radiolabeling yield of ≥98% was observed in all the formulations. Quality control tests indicated the suitability of radiopharmaceutical for intravenous administration. Physiological uptake of Tc-99m HYNIC-RGD2 was observed in the nasopharynx, salivary glands, liver, spleen, and intestine. Good uptake of radiotracer was observed in breast lesions of 18 patients. Two patients were observed to be negative. Increased uptake was also seen in metastatic sites in two patients and in lymph nodes in three patients. Scintigraphy findings were in corroboration with pathological observations. Conclusion The single vial cold kit based radiolabeling of Tc-99m HYNIC-RGD2 is facile leading to its easy availability. Tc-99m HYNIC-RGD2 is a promising radiopharmaceutical which can be used for the molecular imaging of angiogenesis in breast carcinoma patients.

Monte Carlo‐derived 99mTc uptake quantification with commercial planar MBI: Tumor and breast activity concentrations

“…1,18 A PubMed search of "molecular breast imaging technetium-99 m" manuscripts published since 2020 reveals on-going in vitro, pre-clinical, and even some initial human trials using 99m Tc-labelled antibodies and affibodies, gold and silicon nanoparticles, and peptides and proteins to visualize, for example, general breast tumors, [19][20][21] human epidermal growth factor receptor 2 and folate receptor expression in breast tumors, [22][23][24][25][26] epithelial cell adhesion molecules expression in triple negative breast cancers, 27 and even angiogenesis via α v β 3 -integrin receptor targets. 28,29 Thanks to improvements in MBI system sensitivity and resolution, largely due to the optimization of the detector and collimator design, 18 MBI with proper quantification techniques may be uniquely positioned to become an alternative modality to whole-body SPECT/CT to image these new 99m Tc-labelled tracers.…”

“…Looking beyond 99m Tc‐sestamibi, the only radiotracer routinely used for clinical MBI preferentially localized in mitochondria of malignant cancer cells but also localized in varying levels within benign breast tissues, there are many new 99m Tc‐labelled radiotracers are actively under development and are being designed to more specifically target and even differentiate breast cancers 1,18 . A PubMed search of “molecular breast imaging technetium‐99 m” manuscripts published since 2020 reveals on‐going in vitro, pre‐clinical, and even some initial human trials using 99m Tc‐labelled antibodies and affibodies, gold and silicon nanoparticles, and peptides and proteins to visualize, for example, general breast tumors, 19–21 human epidermal growth factor receptor 2 and folate receptor expression in breast tumors, 22–26 epithelial cell adhesion molecules expression in triple negative breast cancers, 27 and even angiogenesis via α v β 3 ‐integrin receptor targets 28,29 . Thanks to improvements in MBI system sensitivity and resolution, largely due to the optimization of the detector and collimator design, 18 MBI with proper quantification techniques may be uniquely positioned to become an alternative modality to whole‐body SPECT/CT to image these new 99m Tc‐labelled tracers.…”