Noninvasive evaluation of PD-L1 expression in non-small cell lung cancer by immunoPET imaging using an acylating agent-modified antibody fragment.

Purpose: The aim of this study was to explore an effective I labeling strategy and improve the signal-to-noise ratio when evaluating the expression of PD-L1 using an I-iodinated durvalumab (durva) F(ab') fragment.

Methods: The prepared durva F(ab') fragments were incubated with N-succinimidyl-3-(4-hydroxyphenyl) propionate (SHPP); after purification, the HPP-durva F(ab') was iodinated using Iodo-Gen method. After the radiochemical purity, stability, and specific activities were determined, the binding affinities of probes prepared using different labeling strategies were compared in vitro.

A personal acquisition time regimen of Ga-DOTATATE total-body PET/CT in patients with neuroendocrine tumor (NET): a feasibility study.

Background: The injection activity of tracer, acquisition time, patient-specific photon attenuation, and large body mass, can influence on image quality. Fixed acquisition time and body mass related injection activity in clinical practice results in a large difference in image quality. Thus, this study proposes a patient-specific acquisition time regimen of  Ga-DOTATATE total-body positron emission tomography-computed tomography (PET/CT) to counteract the influence of body mass (BM, kg) on image quality, and acquire an acceptable and constant image of patients with neuroendocrine tumors (NETs).

P2X7 receptor-specific radioligand F-FTTM for atherosclerotic plaque PET imaging.

Purpose: P2X7 receptors have been considered as a promising biomarker for vulnerable atherosclerotic plaques, which are highly expressed by that instability-associated factors such as macrophages. Thus, we aim to investigate the feasibility of using specific P2X7-targeted F-labeled tracer F-FTTM ((2-chloro-3-[F]fluorophenyl)[1,4,6,7-tetrahydro-1-(2-pyrimidinyl)-5H-1,2,3-triazolo[4,5-c]pyridin-5-yl]methanone) for PET study of vulnerable atherosclerotic plaques identification.

Method: The radioligand F-FTTM was achieved based on the copper-mediated radiofluorination of arylstannane.

Dynamic monitoring of active calcification in atherosclerosis by F-NaF PET imaging.

The objective was to dynamically monitor the progression of atherosclerotic plaques in ApoE mice with F-NaF PET imaging. The ApoE mice were used to develop atherosclerosis models, and the C57BL/6 J mice were used as control. F-NaF PET was performed when the mice were 12, 20, and 30 weeks of age.

A Pretargeted Imaging Strategy for EGFR-Positive Colorectal Carcinoma via Modulation of Tz-Radioligand Pharmacokinetics.

Purpose: Previously, we successfully developed a pretargeted imaging strategy (atezolizumab-TCO/[Tc]HYNIC-PEG-Tz) for evaluating programmed cell death ligand-1 (PD-L1) expression in xenograft mice. However, the surplus unclicked [Tc]HYNIC-PEG-Tz is cleared somewhat sluggishly through the intestines, which is not ideal for colorectal cancer (CRC) imaging. To shift the excretion of the Tz-radioligand to the renal system, we developed a novel Tz-radioligand by adding a polypeptide linker between HYNIC and PEG.

A Pretargeted Imaging Strategy for Immune Checkpoint Ligand PD-L1 Expression in Tumor Based on Bioorthogonal Diels-Alder Click Chemistry.

Purpose: The use of antibodies as tracers requires labeling with isotopes with long half-lives due to their slow pharmacokinetics, which creates prohibitively high radiation dose to non-target organs. Pretargeted methodology could avoid the high radiation exposure due to the slow pharmacokinetics of antibodies. In this investigation, we reported the development of a novel pretargeted single photon emission computed tomography (SPECT) imaging strategy (atezolizumab-TCO/[99mTc]HYNIC-PEG11-Tz) for evaluating immune checkpoint ligand PD-L1 expression in tumor based on bioorthogonal Diels-Alder click chemistry.

Correction to: SPECT/CT imaging of apoptosis in aortic aneurysm with radiolabeled duramycin.

The original version of this article unfortunately contains errors in Figure 4. An incorrect Figure 4D is published which is actually a repetition of Figure 2C (i.e.

SPECT/CT imaging of apoptosis in aortic aneurysm with radiolabeled duramycin.

The objective of this research was to estimate whether a duramycin probe can be used for apoptosis imaging in patients with aortic aneurysm (AA). Vascular smooth muscle cell (SMC) apoptosis has an important influence on AA development. Thus, non-invasive imaging of SMC apoptosis may be able to evaluate AA progress and risk stratification.

P2X7 PET Radioligand F-PTTP for Differentiation of Lung Tumor from Inflammation.

Site-specific imaging agents play a key role in tumor targeting, but only a few agents are currently available for inflammation targeting. Since the P2X7 receptor (P2X7R) is a promising molecular target for inflammation, we evaluated the potential value of the F-labeled tracer F-PTTP (5-{[2-Chloro-3-(trifluoromethyl)phenyl]carbonyl}-1-pyrimidin-2-yl-4,5,6,7-tetrahydro-1H-[1,2,3]triazolo[4,5-c]pyridin) for targeting P2X7Rs and thus differentiating inflammation from tumors. The radioligand F-PTTP was achieved by a 1-step F-trifluoromethylation reaction.

A Comparison of [Tc]Duramycin and [Tc]Annexin V in SPECT/CT Imaging Atherosclerotic Plaques.

Purpose: Apoptosis is a key factor in unstable plaques. The aim of this study is to evaluate the utility of visualizing atherosclerotic plaques with radiolabeled duramycin and Annexin V.

Procedures: ApoE mice were fed with a high-fat diet to develop atherosclerosis, C57 mice as a control.

Tc-labeled bevacizumab for detecting atherosclerotic plaque linked to plaque neovascularization and monitoring antiangiogenic effects of atorvastatin treatment in ApoE mice.

Atherosclerotic neovascularization plays a significant role in plaque instability as it provides additional lipids and inflammatory mediators to lesions, and resulting in intraplaque hemorrhage. Vascular endothelial growth factor-A (VEGF-A) is considered the predominant proangiogenic factor in angiogenesis. Bevacizumab, a humanized monoclonal antibody, specifically binds to all VEGF-A isoforms with high affinity.

Re-188 Enhances the Inhibitory Effect of Bevacizumab in Non-Small-Cell Lung Cancer.

The malignant behaviors of solid tumors such as growth, infiltration and metastasis are mainly nourished by tumor neovascularization. Thus, anti-angiogenic therapy is key to controlling tumor progression. Bevacizumab, a humanized anti-vascular endothelial growth factor (VEGF) antibody, plus chemotherapy or biological therapy can prolong survival for cancer patients, but treatment-related mortality is a concern.