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Background: During anthracycline treatment of cancer, there is a lack for biomarkers of cardiotoxicity besides the cardiac dysfunction. The objective of the present study was to compare [18F]FDG and [123I]MIBG (metaiodobenzylguanidine) in a longitudinal study in a doxorubicin-induced cardiotoxicity rat model. Methods: Male Wistar Han rats were intravenously administered 3 times at 10 days' interval with saline or doxorubicin (5 mg/kg). [123I]MIBG SPECT/CT (single photon emission computed tomography-computed tomography) and simultaneous [18F]FDG PET (positron emission tomography)/7 Tesla cardiac MR (magnetic resonance) imaging acquisitions were performed at 24 h interval before first doxorubicin / saline injection and every 2 weeks during 6 weeks. At 6 weeks, the heart tissue was collected for histomorphometry measurements. Results: At week 4, left ventricle (LV) end-diastolic volume was significantly reduced in the doxorubicin group. At week 6, the decreased LV end-diastolic volume was maintained, and LV end-systolic volume was increased resulting in a significant reduction of LV ejection fraction (47 ± 6% vs. 70 ± 3%). At weeks 4 and 6, but not at week 2, myocardial [18F]FDG uptake was decreased compared with the control group (respectively, 4.2 ± 0.5%ID/g and 9.2 ± 0.8%ID/g at week 6). Moreover, [18F]FDG cardiac uptake correlated with cardiac function impairment. In contrast, from week 2, a significant decrease of myocardial [123I]MIBG heart to mediastinum ratio was detected in the doxorubicin group and was maintained at weeks 4 and 6 with a 45.6% decrease at week 6. Conclusion: This longitudinal study precises that after doxorubicin treatment, cardiac [123I]MIBG uptake is significantly reduced as early as 2 weeks followed by the decrease of the LV end-diastolic volume and [18F]FDG uptake at 4 weeks and finally by the increase of LV end-systolic volume and decrease of LV ejection fraction at 6 weeks. Cardiac innervation imaging should thus be considered as an early key feature of anthracycline cardiac toxicity. [ABSTRACT FROM AUTHOR]

Purpose: Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor outcome and limited therapeutic options. Imaging of IPF is limited to high-resolution computed tomography (HRCT) which is often not sufficient for a definite diagnosis and has a limited impact on therapeutic decision and patient management. Hypoxia of the lung is a significant feature of IPF but its role on disease progression remains elusive. Thus, the aim of our study was to evaluate hypoxia imaging with [18F]FMISO as a predictive biomarker of disease progression and therapy efficacy in preclinical models of lung fibrosis in comparison with [18F]FDG. Methods: Eight-week-old C57/BL6 mice received an intratracheal administration of bleomycin (BLM) at day (D) 0 to initiate lung fibrosis. Mice received pirfenidone (300 mg/kg) or nintedanib (60 mg/kg) by daily gavage from D9 to D23. Mice underwent successive PET/CT imaging at several stages of the disease (baseline, D8/D9, D15/D16, D22/D23) with [18F]FDG and [18F]FMISO. Histological determination of the lung expression of HIF-1α and GLUT-1 was performed at D23. Results: We demonstrate that mean lung density on CT as well as [18F]FDG and [18F]FMISO uptakes are upregulated in established lung fibrosis (1.4-, 2.6- and 3.2-fold increase respectively). At early stages, lung areas with [18F]FMISO uptake are still appearing normal on CT scans and correspond to areas which will deteriorate towards fibrotic lesions at later timepoints. Nintedanib and pirfenidone dramatically and rapidly decreased mean lung density on CT as well as [18F]FDG and [18F]FMISO lung uptakes (pirfenidone: 1.2-, 2.9- and 2.6-fold decrease; nintedanib: 1.2-, 2.3- and 2.5-fold decrease respectively). Early [18F]FMISO lung uptake was correlated with aggressive disease progression and better nintedanib efficacy. Conclusion: [18F]FMISO PET imaging is a promising tool to early detect and monitor lung fibrosis progression and therapy efficacy. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is a progressive disease characterized by an excessive collagen deposition ultimately leading to tissue stiffening and functional decline. Beyond IPF, other progressive pulmonary fibrosis are often associated with connective tissue diseases and may develop in ∼18-32% of patients. Therapeutic options are limited to nintedanib and pirfenidone which are only able to reduce fibrosis progression without curing it. The current lack of biomarker to accurately assess and predict disease progression and therapy efficacy for IPF remains a major clinical concern. Methods: In our study, collagen deposition was monitored in bleomycin-induced lung fibrosis in mice by in vivo molecular imaging using a collagen-targeted radiopharmaceutical, [ 68 Ga]Ga-NODAGA-collagelin. Fibrosis progression was also monitored using computed tomography, the gold standard technique to detect lung fibrosis in patients. Results: We demonstrated that the bleomycin-induced increase in collagen lung content can be accurately quantified by [ 68 Ga]Ga-NODAGA-collagelin PET imaging in correlation with disease stage and severity. The lung uptake of [ 68 Ga]Ga-NODAGA-collagelin was mainly found in fibrotic areas of lungs in bleomycin-receiving mice. Most interestingly, [ 68 Ga]Ga-NODAGA-collagelin PET imaging allowed the in vivo non-invasive monitoring of nintedanib efficacy as well as the anti-fibrotic effect of the JAK inhibitor, tofacitinib. Conclusion: Thus, collagen-targeted PET imaging appears as a promising non-invasive tool for staging, monitoring and prediction of disease progression and therapy efficacy towards personalized medicine in IPF., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Neurotensin receptor 1 (NTS 1 ) is involved in the development and progression of numerous cancers, which makes it an interesting target for the development of diagnostic and therapeutic agents. A small molecule NTS 1 antagonist, named [ 177 Lu]Lu-IPN01087, is currently evaluated in phase I/II clinical trials for the targeted therapy of neurotensin receptor-positive cancers. In this study, we synthesized seven compounds based on the structure of NTS 1 antagonists, bearing different chelating agents, and radiolabeled them with gallium-68 for PET imaging. These compounds were evaluated in vitro and in vivo in mice bearing a HT-29 xenograft. The compound [ 68 Ga]Ga-bisNODAGA- 16 showed a promising biodistribution profile with mainly signal in tumor (4.917 ± 0.776%ID/g, 2 h post-injection). Its rapid clearance from healthy tissues led to high tumor-to-organ ratios, resulting in highly contrasted PET images. These results were confirmed on subcutaneous xenografts of AsPC-1 tumor cells, a model of NTS 1 -positive human pancreatic adenocarcinoma.