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Objective Myocardial fibrosis is a potential mechanism of light-chain myocardial amyloidosis(AL-CA). This research aimed at exploring the correlation between multiparameter cardiac magnetic resonance (CMR) and myocardial fibrosis by relating the CMR myocardial tissue characteristics, the morphological and the functional parameters with gallium-68-labeledfibroblast activation protein inhibitor 04 positron emission tomography (68Ga-FAPI PET). Methods We gave the patients diagnosed with AL-CA in Peking Union Medical College Hospital from August to December 2021 the examinations of CMR and 68Ga-FAPI PET/CT. We recorded and analyzed the information on clinical manifestations and examinations of the patients. Results A total of 23 patients with AL-CA were included, 15 (65.2%)of which were male and the mean age was 58.3±6.5 years. Patients with high 68Ga-FAPI-04 uptake had shown growth in myocardial extracellular volume (ECV), significantly higher than those in the negative group (P=0.047). In addition, patients' myocardial ECV was positively correlated with myocardial FAPI uptake (r=0.628, P=0.001;r=0.727, P < 0.001;r=0.661, P=0.001). Patients in the positive group showd reduced left ventricular (LV) ejection fraction (EF)(P < 0.001).LVEF (r=-0.798, P < 0.001;r=-0.794, P < 0.001; r=-0.795, P < 0.001) and right ventricular (RV)EF (r=-0.735, P < 0.001;r=-0.739, P < 0.001;r=- 0.684, P < 0.001) showd negatively correlated with myocardial FAPI uptake, LV circumferential strain (r=0.668, P < 0.001;r=0.708, P < 0.001;r=0.705, P < 0.001), LV longitudinal strain (r=0.629, P=0.001;r=0.635, P=0.001; r=0.597, P=0.003), and RV longitudinal strain (r=0.575, P=0.004; r=0.792, P < 0.001;r=0.673, P < 0.001) were negatively correlated with myocardial FAPI uptake. Conclusions FAPI-related fibroblast activation is concurrent with CMR-related abnormal myocardial interstitial characteristics that leads to the decreased function of the myocardial movement. Patients with increased FAPI uptake present with increased ECV, decreased EF, and decreased strain with morphological abnormalities.
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Objective:To investigate the capability of 18F-FDG PET/CT imaging in monitoring combined immunotherapy response and detecting immune related adverse events (irAEs) in patients with advanced hepatobiliary carcinoma. Methods:From August 2018 to July 2019, 21 patients (14 males, 7 females, age (58.5±10.0) years) with advanced hepatobiliary carcinoma routinely underwent 66 18F-FDG PET/CT examinations in Peking Union Medical College Hospital. SUV max, the occurrence time and symptoms of irAEs were obtained and analyzed. Therapy response (complete metabolic response (CMR), partial metabolic response (PMR), stable metabolic disease (SMD), progressive metabolic disease (PMD)) was evaluated according to PET response criteria in solid tumors (PERCIST). Results:(1) Clinical results. Twenty-two irAEs occurred in 16 patients, while were not found in 5 patients. Six organs were involved, including thyroiditis(8), colitis(5), pneumonitis(4), rash(2), hepatitis(2), myositis and fasciitis(1). The appearance time of each irAEs were (103.0±58.0), (141.6±103.5), 34.0(6.0, 308.8), 9 and 117, 62 and 67, and 87 d after therapy, respectively. PET/CT detected all pneumonitis and myositis and fasciitis, but no rash and hepatitis were found. For colitis and thyroiditis, PET/CT detected 4 and 6 times respectively. (2) PET/CT signs of irAEs. Except thyroiditis, all irAEs lesions exhibited exudative changes in CT and high-avidity in PET. SUV max of the lesions were 9.0(7.9, 17.6) (colitis), 7.1±3.2 (thyroiditis), 5.3 and 8.6 (pneumonitis), 4.1 (myositis and fasciitis), respectively. (3) Therapy assessment. Among 21 patients, there were 7 for PMR, 9 for SMD, 5 for PMD, which were 7, 8, 1 in patients with irAEs and 0, 1, 4 in patients without irAEs. Conclusions:Patients with advanced hepatobiliary carcinoma can benefit from combined immunotherapy. 18F-FDG PET/CT can be used to evaluate the efficacy of immunotherapy by detecting the changes of tumor lesions and the occurrence of irAEs simultaneously. However, it is necessary to use CT to distinguish tumor progression from irAEs.
ABSTRACT
Systematic light chain (AL) amyloidosis is the most common forms of amyloidosis, which manifests as multiple organ system involvement, rapid progress, dire prognosis, difficult therapy and high mortality. Many patients may miss the optimal treatment as a result of not being diagnosed timely. Therefore, early diagnosis and assessment of involved extent of AL are clinical focuses. Related clinical studies have demonstrated that nuclear medicine imaging can be non-invasive in detecting amyloid deposits. It can not only early assess the extent and distribution of amyloid deposits in systemic AL amyloidosis, but also offer the indications for risk stratification, treatment response monitoring and prognosis assessment of the patients, especially for positron amyloidosis-specific tracers, which may have great prospects in the future. This review summarizes the application of nuclear medicine imaging in the systematic AL amyloidosis.
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Immune checkpoint inhibitors (ICIs) have shown significant efficacy in clinical trials and applications of various malignant tumors, and have been approved for clinical application in China. ICIs can cause immune-related adverse events (irAEs), which may affect any organs. Early identification and appropriate treatment can improve patient outcome. 18F-FDG PET/CT is capable of early detection of irAEs and provides effective clinical guidance. This article reviews the clinical application of 18F-FDG PET/CT in detecting irAEs, including typical imaging findings and research progress.
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Objective:To investigate the application of different imaging methods of 99Tc m-pyrophosphate (PYP) in the diagnosis and pathological classification of cardiac amyloidosis (CA). Methods:A total of 31 patients (22 males, 9 females, age 21-81(57.2±13.4) years) with suspected CA who underwent 99Tc m-PYP dual-phase scintigraphy (early-phase: 1 h, delay-phase: 2-3 h) and SPECT/CT (1 h) between December 2018 and December 2019 in Peking Union Medical College Hospital were retrospectively included. Taking clinical diagnosis as the standard, the results of visual score (≥2, positive) and semi-quantitative values (heart to contralateral lung (H/CL)≥1.5, positive) of 99Tc m-PYP uptake in dual-phase scintigraphy and SPECT/CT imaging were analyzed. One-way analysis of variance and Bonferroni test were used to analyze the data. Results:Among 31 patients with suspected CA, 15 were clinically diagnosed as CA (5 patients with transthyretin-related CA (ATTR-CA) and 10 patients with light chain CA (AL-CA)) and 16 were diagnosed as non-CA. All 5 patients with ATTR-CA had positive dual-phase scintigraphy and SPECT/CT imaging results. Three out of 10 patients with AL-CA had positive early-phase scintigraphy whereas negative delay-phase scintigraphy and SPECT/CT imaging results. Sixteen patients who were clinically diagnosed as non-CA had negative dual-phase scintigraphy and SPECT/CT imaging results. The sensitivity (5/5), specificity (10/10), positive predictive value (5/5), negative predictive value (10/10) and accuracy (15/15) of delay-phase scintigraphy and SPECT/CT imaging were the same. Among 31 patients, 16 patients carried transthyretin-related (TTR) gene mutation, and 4 of them who clinically diagnosed as variant ATTR (ATTRv) had positive image findings while 12 of them who not clinically diagnosed as CA had negative image findings. There were significant differences in H/CL between ATTR-CA group and AL-CA group in early-phase (2.11±0.24 vs 1.31±0.07) and delay-phase (2.02±0.19 vs 1.30±0.05; F values: 75.41 and 87.15, Bonferroni test, both P<0.01). Conclusions:99Tc m-PYP delay-phase scintigraphy and SPECT/CT have high diagnostic efficiencies in ATTR-CA, helping to determine the pathological classification of CA; while early-phase scintigraphy has false positive results. Moreover, 99Tc m-PYP imaging is helpful to detect CA in patients with TTR gene mutation.
ABSTRACT
Transthyretin-related amyloid cardiomyopathy (ATTR-CM) is a disease caused by the depo-sition of insoluble amyloid fibers formed by the misfolding of transthyretin precursor protein in the intercellular space of cardiomyocytes. This lesion may lead to myocardial dysfunction, cogestive heart failure, and death.When diagnosed earlier, the patient can be treated with drugs as soon as possible to intervene in the progress of the disease, so as to effectively improve the patient's prognosis.99mtechnetium-pyrophosphate (99Tcm-PYP)single-photon emission computed tomography (SPECT) has been widely used in the imaging examination of cardiac amyloidosis (CA) in recent years. While achieving early non-invasive diagnosis, accurate pathological classification can be obtained through Perugini visual score analysis, semi-quantitative analysis of heart to contralateral lung (H/CL) ratio, and SPECT image analysis. This article presents the application, methods, and the precautions of 99Tcm-PYPSPECT in the diagnosis of ATTR-CM, aiming to provide clinical reference for the application of this technology.
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Objective:To prepare 68Ga-fibroblast activation protein inhibitor (FAPI)-04, and evaluate its biodistribution and imaging characteristics in animals and healthy volunteers, in order to investigate the clinical translation potential. Methods:68Ga-FAPI-04 was synthesized by a manual method and its radiolabeling yield, radiochemical purity, and stability ( in vivo and in vitro) were analyzed. ICR mice ( n=16) were scarified at 5, 30, 60 and 120 min postinjection of 68Ga-FAPI-04 (1.11 MBq) to measure radioactive counts in main organs. The dynamic mircoPET imaging was acquired for 60 min on 3 ICR mice, and tumor imaging capabilities were examined with nude mice bearing HepG2 tumors. Furthermore, 2 healthy volunteers (1 male with age of 64 years, 1 female with age of 56 years) were recruited for the investigation of probe biodistribution in humans. A serial whole-body dynamic PET/CT scan was performed immediately following injection. Results:68Ga-FAPI-04 was synthesized within 20 min with the radiochemical yield of (68.7±4.0)% (decay corrected). The radiochemical purities of 68Ga-FAPI-04 were over 99% and the products were stable for 180 min in vitro and for 90 min in blood. 68Ga-FAPI-04 was mainly cleared through urinary tracts, while other organs only showed mild tracer accumulation. MicroPET imaging showed high uptake of 68Ga-FAPI-04 in the tumor tissue of mice, and the ratio of tumor/liver was 2.14±0.01 (35 min). The PET/CT imaging results of healthy volunteers revealed 68Ga-FAPI-04 could be quickly cleared. Conclusion:68Ga-FAPI-04 has many advantages for PET imaging, such as easy labeling, good stability, quick clearance and low background signals in the liver, which can be used as an attractive PET tracer for detection hepatocellular carcinoma.