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COVID-19 is a multisystemic disease, and hence its potential manifestations on nuclear medicine imaging can extend beyond the lung. Therefore, it is important for the nuclear medicine physician to recognize these manifestations in the clinic. While FDG-PET/CT is not indicated routinely in COVID-19 evaluation, its unique capability to provide a functional and anatomical assessment of the entire body means that it can be a powerful tool to monitor acute, subacute, and long-term effects of COVID-19. Single-photon scintigraphy is routinely used to assess conditions such as pulmonary embolism, cardiac ischemia, and thyroiditis, and COVID-19 may present in these studies. The most common nuclear imaging finding of COVID-19 vaccination to date is hypermetabolic axillary lymphadenopathy. This may pose important diagnostic and management dilemmas in oncologic patients, particularly those with malignancies where the axilla constitutes a lymphatic drainage area. This article aims to summarize the relevant literature published since the beginning of the pandemic on the intersection between COVID-19 and nuclear medicine. • Clinical and imaging manifestations of COVID-19 may occur outside of the respiratory tract and extend beyond the acute phase. • Evidence of inflammation involving any organ system should be carefully sought in patients with known or suspected COVID-19. • The most common nuclear imaging finding of COVID-19 vaccination is hypermetabolic axillary lymphadenopathy. [ABSTRACT FROM AUTHOR]

Objectives: Often peptides used in synthesis of radiopharmaceutical PET tracers are lipophilic and adhere to the walls of container closure systems (CCS) such that costly peptide and product are not fully recoverable after synthesis occurs. This investigation compares a standard United States Pharmacopeia (USP) Type I borosilicate glass CCS to a cyclic polyolefin copolymer Crystal Zenith® (CZ) CCS, for 68Ga-chloride and 68Ga-DOTATOC ([68Ga] Ga-DOTA-d-Phe1-Tyr3-octreotide) retention in the reaction vial after labeling. Methods: 68Gallium labeling of DOTATOC was conducted by adding 68Ga-chloride, 2M HEPES (4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid) or 0.75M sodium acetate, and 1–30µg of DOTATOC into the CZ or glass CCS. The reaction mixture was heated for 15min and cooled to room temperature. The crude reaction mixture was then withdrawn via syringe, for final processing. The CCS was then assayed using a dose calibrator to determine the amount of retained 68Ga-DOTATOC. Statistical significance was assessed using an unpaired Student's t-test. Results: In all experiments (n=72) with various amounts of peptide and different buffering systems, the CZ CCS retained less activity than the glass CCS. Using 2M HEPES and 15µg or 30µg of DOTATOC, the CZ CCS retained approximately 10% less of the labeled DOTATOC compared to the glass CCS (p<0.05). Utilizing either a sodium acetate or a HEPES buffering system with 15µg or 30µg of DOTATOC, the CZ CCS retained approximately 2.5% less of the total reaction activity compared to the glass CCS (p<0.05). Product yield was equivalent in glass and CZ CCS under the same reaction conditions. Both the CZ and glass vials showed no retention of 68Ga-chloride. Conclusion: For applications involving the labeling of peptides such as 68Ga-DOTATOC, the CZ CCS compared to the glass CCS, results in an improved recovery of product. [ABSTRACT FROM AUTHOR]

Imaging strategies that detect early stage esophageal squamous cell carcinoma (ESCC) could improve clinical outcomes, when combined with endoscopic approaches. Periostin is an integrin-binding protein that is important in the tumor microenvironment. We created a fluorescent-labeled antibody that recognizes periostin and binds specifically to ESCC xenograft tumors in mice. In L2-cre;p120ctnLoxP/LoxP mice, which develop squamous cell cancers that resemble human ESCC, we visualized the probe in preneoplastic and neoplastic esophageal lesions using near-infrared fluorescent imaging with upper-gastrointestinal endoscopy. Periostin might be a biomarker of the esophageal tumor microenvironment that can be used to detect preneoplastic lesions. [Copyright &y& Elsevier]

Purpose: Response criteria of glioblastoma after chemoradiation do not account for metabolic changes that occur after treatment. The purpose of this study is to evaluate the utility of positron emission tomography (PET) imaging with C11 methionine (MET) (MET-PET) for detecting changes that occur after chemoradiation therapy and the value of molecular biomarkers for predicting the magnitude of metabolic response.Methods and Materials: Patients with newly diagnosed glioblastoma undergoing standard chemoradiation treatment were enrolled in this prospective imaging study, with MET-PET scan performed within 3 days after surgical resection and again at 4 weeks after completion of chemoradiation. Near contemporaneous contrast-enhanced magnetic resonance imaging was performed within 2 weeks of each MET-PET scan. MET-PET imaging was analyzed for maximum standardized uptake value (SUV), SUVmean, and SUVvolume on a multimodality workstation.Results: A total of 18 patients underwent baseline postoperative MET-PET imaging, 14 of whom underwent postchemoradiation MET-PET imaging. Among those who showed residual MET-avid disease on immediate postoperative MET-PET scans and underwent postchemoradiation MET-PET imaging (n = 10), mean ΔSUVmax was -40% (range -100% to 0%), mean ΔSUVmean was -35% (range -100% to 0%), and mean ΔSUV volume was -64% (range -100% to 0%). The Δtumor/brain reference was -40% (range -100% to 0%) using SUVmax and -35% (range -100% to 0%) using SUVmean. In contrast, none of the T2-weighted images on contrast-enhanced magnetic resonance imaging showed a >25% reduction in abnormal T2/fluid-attenuated inversion recovery signal on visual assessment. ΔSUVmax, ΔSUVmean, and ΔSUVvolume correlated with O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status (P = .01), but not with epidermal growth factor receptor or c-MET amplification status. All patients were IDH-1 wildtype.Conclusions: MET-PET scanning shows a significant decrease in metabolic signal at 1 month after chemoradiation compared with the immediate postoperative period, even when T2/fluid-attenuated inversion recovery changed little. MGMT promoter methylation status further predicts differential metabolic responses. MET-PET may be a useful tool for delineation of radiation targets and assessment of response. [ABSTRACT FROM AUTHOR]

Cancer cells are surrounded by a complex and highly dynamic tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs), a critical component of TME, contribute to cancer cell proliferation as well as metastatic spread. CAFs express a variety of biomarkers, which can be targeted for detection and therapy. Most importantly, CAFs express high levels of fibroblast activation protein (FAP) which contributes to progression of cancer, invasion, metastasis, migration, immunosuppression, and drug resistance. As a consequence, FAP is an attractive theranostic target. In this review, we discuss the latest advancement in targeting FAP in oncology using theranostic biomarkers and imaging modalities such as single-photon emission computed tomography (SPECT), positron emission tomography (PET), computed tomography (CT), fluorescence imaging, and magnetic resonance imaging (MRI). [Display omitted] [ABSTRACT FROM AUTHOR]

SiO 2 -CaO-P 2 O 5 based bioglass (BG) systems constitute a group of materials that have wide applications in bone implants. Chitosan (Cn) is a biocompatible and osteoconductive natural polymer that can promote wound healing. In this study, bioactivity of chitosan/bioglass (CnB) composites as minimally invasive bone regenerative materials was assessed both in vitro and in vivo . Injectability tests and scanning electron microscopy (SEM) results demonstrated the formation of uniform injectable paste-like composites using BG particles and Cn. Fourier transform infrared spectroscopy (FTIR) and SEM images confirmed hydroxyapatite deposition in vitro after incubation in simulated body fluid (SBF). Higher BG content in the composite correlated with increased human osteoblast proliferation. An in vivo study in a rat spinal fusion model confirmed that increasing the amount of BG improved osteoconductivity. Manual palpation, radiographic images and pathological assessments proved that the composites promote bone formation. Based on these data, the synthesized composites have a potential application in orthopedic and reconstructive surgeries as a minimally invasive bone substitute. [ABSTRACT FROM AUTHOR]

Summary: Pancreatic ductal adenocarcinoma (PDAC) is associated with marked fibrosis and stromal myofibroblasts, but their functional contribution remains unknown. Transgenic mice with the ability to delete αSMA+ myofibroblasts in pancreatic cancer were generated. Depletion starting at either noninvasive precursor (pancreatic intraepithelial neoplasia) or the PDAC stage led to invasive, undifferentiated tumors with enhanced hypoxia, epithelial-to-mesenchymal transition, and cancer stem cells, with diminished animal survival. In PDAC patients, fewer myofibroblasts in their tumors also correlated with reduced survival. Suppressed immune surveillance with increased CD4+Foxp3+ Tregs was observed in myofibroblast-depleted mouse tumors. Although myofibroblast-depleted tumors did not respond to gemcitabine, anti-CTLA4 immunotherapy reversed disease acceleration and prolonged animal survival. This study underscores the need for caution in targeting carcinoma-associated fibroblasts in PDAC. [ABSTRACT FROM AUTHOR]