Ocena przydatności hepatotropowego środka kontrastowego Teslascan (Mn-DPDP) w wykrywaniu zmian ogniskowych w wątrobie

Background: The purpose of our study was to evaluate the usefulness of the hepatotropic contrast agent Teslascan (Mn-DPDP) in the detection of focal hepatic lesions. Material/Methods: A prospective study was performed in 24 patients (12 men, 12 women) with 82 confirmed focal hepatic lesions, in whom the hepatotropic contrast agent Mn-DPDP (Teslascan) was administered. The examinations were performed on a 1.5T unit (Philips Gyroscan). The sensitivity of hepatic lesions detection were compared in T2W, TSE, T2W STIR, T1W GRE, and T1W GRE sequences, 15-30 minutes after intravenous administration of Mn-DPDP. Results: In T2W TSE sequences 64 focal lesions were detected (sensitivity 78%); in T2W STIR sequences, 70 lesions (sensitivity 85%); in T1W GRE sequences, 65 lesions (sensitivity 79%); in T1W GRE sequences after Mn-DPDP administration, 77 lesions (sensitivity 94%). The combined sensitivity of evaluation using all the sequences obtained before Mn-DPDP administration (T2W TSE, T2W STIR, T1W GRE) was 88%. Conclusions: MR examination with the use of MN-DPDP yielded higher sensitivity in hepatic lesion detection compared to unenhanced T2W TSE, T2W STIR and T1W GRE sequences

Trastuzumab-Modified Gold Nanoparticles Labeled with ²¹¹At as a Prospective Tool for Local Treatment of HER2-Positive Breast Cancer

Highly localized radiotherapy with radionuclides is a commonly used treatment modality for patients with unresectable solid tumors. Herein, we propose a novel α-nanobrachytherapy approach for selective therapy of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. This uses local intratumoral injection of 5-nm-diameter gold nanoparticles (AuNPs) labeled with an α-emitter (211At), modified with polyethylene glycol (PEG) chains and attached to HER2-specific monoclonal antibody (trastuzumab). The size, shape, morphology, and zeta potential of the 5 nm synthesized AuNPs were characterized by TEM (Transmission Electron Microscopy) and DLS (Dynamic Light Scattering) techniques. The gold nanoparticle surface was modified by PEG and subsequently used for antibody immobilization. Utilizing the high affinity of gold for heavy halogens, the bioconjugate was labelled with 211At obtained by α irradiation of the bismuth target. The labeling yield of 211At was greater than 99%. 211At bioconjugates were stable in human serum. Additionally, in vitro biological studies indicated that 211At-AuNP-PEG-trastuzumab exhibited higher affinity and cytotoxicity towards the HER2-overexpressing human ovarian SKOV-3 cell line than unmodified nanoparticles. Confocal and dark field microscopy studies revealed that 211At-AuNP-PEG-trastuzumab was effectively internalized and deposited near the nucleus. These findings show promising potential for the 211At-AuNP-PEG-trastuzumab radiobioconjugate as a perspective therapeutic agent in the treatment of unresectable solid cancers expressing HER2 receptors