A Comparative Study of 18F-FAPI-42 and 18F-FDG PET/CT for Evaluating Acute Kidney Injury in Cancer Patients.

PURPOSE: Compare the value of imaging using positron 18F-labeled fibroblast activation protein inhibitor-42 (18F-FAPI-42) and 18F-labeled deoxyglucose (18F-FDG) for assessment of AKI. PROCEDURES: This study analyzed cancer patients who received 18F-FAPI-42 and 18F-FDG PET/CT imaging. Eight patients had AKI with bilateral ureteral obstruction (BUO), eight had BUO (CKD1-2) with no acute kidney disease (AKD), and eight had no ureteral obstruction (UO) with normal renal function. The average standardized uptake value (SUVave) of the renal parenchyma (RP-SUVave), the blood pool SUVave (B- SUVave), SUVave in the highest region of the renal collective system (RCS-SUVave), and the highest serum creatinine level (top SCr) were recorded. RESULTS: The 18F-FAPI-42 and 18F-FDG results showed that radiotracer of renal parenchyma was more concentrated in the AKI group than in the other two groups, whereas the RP-SUVave from 18F-FAPI-42 was higher than that from 18F-FDG in the AKI group (all P < 0.05). 18F-FAPI-42 imaging in the AKI group showed uptake by the renal parenchyma with a diffuse increase, but very little radiotracer in the renal collecting system, similar to a "super kidney scan." The renal parenchyma also had an increase of SUVave, with accumulation of radiotracer in the renal collecting system. AKI was more severe when a patient had a "super kidney scan" in both kidneys (P < 0.05). The B-SUVave level was higher in the AKI group than in the other two groups in 18F-FAPI-42 (both P < 0.05). CONCLUSIONS: 18F-FAPI-42 imaging had higher RP-SUVave than 18F-FDG imaging in cancer patients who had BUO with AKI. An increased renal parenchyma uptake in both kidneys and low radiotracer distribution in the collecting system suggest more severe AKI.

Radiosynthesis and biological evaluation of 18F-labeled 4-anilinoquinazoline derivative (18F-FEA-Erlotinib) as a potential EGFR PET agent.

Epidermal growth factor receptor (EGFR) has gained significant attention as a therapeutic target. Several EGFR targeting drugs (Gefitinib and Erlotinib) have been approved by US Food and Drug Administration (FDA) and have received high approval in clinical treatment. Nevertheless, the curative effect of these medicines varied in many solid tumors because of the different levels of expression and mutations of EGFR. Therefore, several PET radiotracers have been developed for the selective treatment of responsive patients who undergo PET/CT imaging for tyrosine kinase inhibitor (TKI) therapy. In this study, a novel fluorine-18 labeled 4-anilinoquinazoline based PET tracer, 1N-(3-(1-(2-18F-fluoroethyl)-1H-1,2,3-triazol-4-yl)phenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine (18F-FEA-Erlotinib), was synthesized and biological evaluation was performed in vitro and in vivo. 18F-FEA-Erlotinib was achieved within 50min with over 88% radiochemical yield (decay corrected RCY), an average specific activity over 50GBq/µmol, and over 99% radiochemical purity. In vitro stability study showed no decomposition of 18F-FEA-Erlotinib after incubated in PBS and FBS for 2h. Cellular uptake and efflux experiment results indicated the specific binding of 18F-FEA-Erlotinib to HCC827 cell line with EGFR exon 19 deletions. In vivo, Biodistribution studies revealed that 18F-FEA-Erlotinib exhibited rapid blood clearance both through hepatobiliary and renal excretion. The tumor uptake of 18F-FEA-Erlotinib in HepG2, HCC827, and A431 tumor xenografts, with different EGFR expression and mutations, was visualized in PET images. Our results demonstrate the feasibility of using 18F-FEA-Erlotinib as a PET tracer for screening EGFR TKIs sensitive patients.

CKD-EPI creatinine-cystatin C glomerular filtration rate estimation equation seems more suitable for Chinese patients with chronic kidney disease than other equations.

BACKGROUND: The aim of this study was to identify the optimal equation that accurately estimates the glomerular filtration rate (GFR) and the chronic kidney disease (CKD) stage in the Chinese population. METHODS: A total of 1296 Chinese patients aged 18-65 years old were enrolled in this study. The estimated GFRs (eGFRs) calculated separately by three Diet in Renal Disease (MDRD) equations and three Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations were compared with the reference GFR (rGFR) measured by the 99Tcm-DTPA renal dynamic imaging method. RESULTS: By Bland-Altman analysis, eGFRcys and eGFRscr_cys performed similarly, showing the tightest limits of agreement among the six equations. They also achieved the first and second highest 30% and 50% accuracies. Using a combination of the serum creatinine and cystatin C levels (eGFRscr_cys) could improve the bias (-0.3 for eGFRscr_cys) of the equation and achieve the highest diagnostic accuracy for renal insufficiency (AUC60, 0.953; P < 0.05, except for eGFR_MDRD). All equations predicted stage 3 CKD with moderate accuracy (49.7-51.4%) and stage 5 CKD with good accuracy (90.2-96.4%). For stage 1 CKD, eGFRcys showed a higher percentage of misclassification than the other equations. All equations seemed to perform poorly at predicting stage 2 and 4 CKD, as compared to the other CKD stages. eGFRscr_cys was the best-performing equation in terms of accurate classification of the CKD stage based on the overall performance (kappa value, 0.423). CONCLUSION: For a Chinese population, the CKD-EPIscr_cys equation seems more suitable for estimating the GFR than the other equations. Each equation had its own advantages in predicting different CKD stages.

Diagnosis and treatment of diffusible Penicillium marneffei in human immunodeficiency virus-negative patients: A challenge for the physician.

Penicillium marneffei infection in human immunodeficiency virus (HIV)-negative patients is addressed far less often. In this article, a small cohort of HIV-negative patients who disseminated P. marneffei infection was included. Sites of infection were found from blood culture, as subcutaneous nodules, or from lymph node biopsy. Fever, rash, swollen lymph nodes, anaemia and weight loss were common characteristics in most infected patients. The signs and symptoms are diverse and create challenges for accurate diagnosis. This paper will assist our understanding of this disease and contribute to an appropriate regime of therapy, thus improving the health of P. marneffei-positive patients.

[Blue rubber bleb nevus syndrome complicated by a ventricular septal defect: a case report].

OBJECTIVE: The co-occurrence of blue rubber bleb nevus syndrome (BRBNS) and ventricular septal defects is rare. Here we present a case of BRBNS in a 15-year-old boy who was born with multiple cavernous hemangiomas and a ventricular septal defect. Examinations revealed the presence of hemangioma lesions in the subcutaneous and mucosal tissues as well as in the cerebrum, nasopharynx, tongue, esophagus, gastric body, sigmoid colon and adrenal gland. Combined imaging modalities played an important role in the diagnosis of hemangioma lesions.

[Radioimmunoimaging of lymphoma in mice with a two-step pretargeting strategy using biotinyled CD45 monoclonal antibody and (188)Re-avidin].

OBJECTIVE: To establish a two-step pretargeting approach to lymphoma radioimmunoimaging in mice using biotinynaled CD45 monoclonal antibody (McAb) and (188)Re-avidin in a tumor-bearing mouse model. METHODS: Six Nod-Scid mice bearing lymphoma cell xenograft were randomized to receive either an intravenous injection of 50 µg/200 µL biotinyled CD45 McAb followed 24 h later by an intraperitoneal injection of 3.7 MBq (50 µg/100 µL) (188)Re-avidin (two-step pretargeting group), or a single intravenous injection of 3.7 MBq (100 µg/100 µL) (188)Re-CD45 McAb (control group). SPECT was performed at 0.5, 1, 6 and 23 h post-injection to characterize (188)Re isotope biodistribution. At 24 h pos-injection, the mice were sacrificed for measurement of radioactivity uptake in the tumor and normal tissues and calculation of the tumor-to-non-tumor (T/NT) ratios. RESULTS: SPECT showed that the two-step pretargeting method resulted in a low radioactivity in the blood pool during the imaging and a concentrated radioactivity in the liver and spleen. The transplanted tumor began to be displayed at 1 h post-injection and was clearly displayed at 1-6 h; the images were clear even at 23 h. With the two-step pretargeting method, the radioactive uptake at 24 h post-injection were (1.34∓0.52)%, (6.77∓2.32)%, and (2.81∓1.25)% in the tumor, kidney and liver, respectively, with low radioactivity levels in other organs and high tumor/blood and tumor/muscle ratios (4.28∓0.82 and 8.00∓0.88, respectively). In the control group, SPECT revealed intense radioactivity in the liver, spleen, and kidneys with obscure display of the tumor; at 20 h, the radioactivity in the blood pool remained high but that in the tumor was low, and the tumor/blood and tumor/muscle ratios at 24 h were only 0.58∓0.06 and 3.21∓0.24, respectively. CONCLUSION: Compared with (188)Re-CD45 McAb, the two-step pretargeting approach exhibits a good specificity in targeting lymphoma with an increased T/NT ratio in mice and allows early tumor display at 1 h post-injection.

[Preparation of (99m)Tc-EDTA-MN and Its Bioimaging in Mouse].

BACKGROUND AND OBJECTIVE: Hypoxia is an important biological characteristics of solid tumor, it is not sensitive to radiotherapy and chemotherapy for which is the presence of hypoxic cell, thus increasing their resistance to conventional radiotherapy and chemotherapy, therefore, the detection of hypoxia degree of tumor tissue is of great significance. The hypoxia imaging of nuclear medicine can reflect the degree of tissue hypoxia, which can selectively retained on the hypoxic cells or tissues, including nitroimidazole and non nitroimidazole; the nitroimidazole is widely and deeply researched as hypoxic celles developer in China and abroad at present. The research about application of radionuclide labelled technique has clinical application value to develop the hypoxia imaging agent EDTA-MN complexes which was labeled. To study the feasibility of (99m)Tc by direct labeling method, the radiochemical properties evaluation of (99m)Tc-EDTA-MN, and observe the distribution characteristics of (99m)Tc radiolabeled EDTA-MN in the xenograft lung cancer nude mice bearing non-small cell lung cancer cell (A549), and provide experimental evidence for its further research and application. METHODS: The radiolabeling of EDTA-MN with (99m)Tc was performed with direct labeling method, respectively, on the reaction dosage (10 mg, 5 mg, 2 mg), stannous chloride dosage (8 mg/mL, 4 mg/mL, 2 mg/mL), mark system pH (2, 4, 5, 6) one by one test, using orthogonal design analysis, to find the optimal labeling conditions. Labelling rate, radiochemical purity, lipid-water partition coefficient and in vitro stability in normal saline (NS) were determined by TLC and HPLC, and the preliminary study on the distribution of (99m)Tc-EDTA-MN in nude mice. RESULTS: The labeling rate of 99mTc-EDTA-MN with the best labeling conditions was (84.11±2.83)%, and the radiochemical purity was higher than 90% by HPLC purification, without any notable decomposition at room temperature over a period of 12 h. The partition coefficient was lgP=-3.05, indicated that this complex was hydrophilic. At 3 h post-injection, the imaging of (99m)Tc-EDTA-MN in nude mice bearing non-small cell lung cancer cell showed that more radioactive gathered in bladder at 0.5 h, the transplanted tumor was clearly imaged at 1 h post-injection, during whole imaging radioactive in other tissues and organs was low. The radioactivity of tumor uptake by using of ROI technology were (88.14±11.59), (123.17±9.06), (98.08±14.40) and (79.87±10.57) at 0.5, 1, 2, 3 h post-injection, and the ratio of T/NT of tumor and liver area were (1.95±0.19), (3.58±0.78), (3.95±0.39) and (5.01±0.28), respectively. (99m)Tc-EDTA-MN could be quickly cleared from the blood in mice primarily through the kidneys, and the radioactivity in other tissues and organs remained low. CONCLUSIONS: (99m)Tc-EDTA-MN can be easily prepared and labeled compound with high labeling rate and stability, it appears to be suitable for further experiments requirement in vivo and in vitro application.