Unlabelled: Noninvasive in vivo imaging of biologic processes using PET is an important tool in preclinical studies. We observed significant differences in 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) uptake in arthritic ankles and carcinomas between dynamic and static PET measurements when mice breathed oxygen. Thus, we suspected that air or oxygen breathing and the anesthesia protocol might influence (18)F-FLT tracer uptake.
Methods: We injected arthritic, healthy, and CT26 colon carcinoma-bearing mice with (18)F-FLT before static or dynamic small-animal PET measurements. The spontaneously oxygen- or air-breathing mice were kept conscious or anesthetized with ketamine and xylazine during (18)F-FLT uptake before the 10-min static PET measurements. For dynamic PET scans, mice were anesthetized during the entire measurement. (18)F-FLT uptake was reported in percentage injected dose per cubed centimeter by drawing regions of interest around ankles, carcinomas, and muscle tissue. Additionally, venous blood samples were collected before (18)F-FLT injection and after PET measurement to analyze pH, carbon dioxide partial pressure (pCO(2)), and lactate values.
Results: A significantly reduced (18)F-FLT uptake was measured in arthritic ankles and in CT26 colon carcinomas when the mice breathed oxygen and were conscious during tracer uptake, compared with mice that were anesthetized during (18)F-FLT uptake. Breathing air completely abolished this phenomenon. Analysis of blood samples that were obtained from the mice before (18)F-FLT injection and after the PET scan implicated respiratory acidosis that was induced by oxygen breathing and consciousness during tracer uptake. Acidosis was found to be the primary factor responsible for the reduced (18)F-FLT uptake, as reflected by increased pCO(2) and reduced pH and lactate values.
Conclusion: Oxygen-breathing conscious mice sustained respiratory acidosis and, consequently, reduced cell proliferation and (18)F-FLT uptake in arthritic ankles and CT26 colon carcinomas. Thus, we suggest the use of air instead of oxygen breathing for (18)F-FLT PET measurements.
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http://dx.doi.org/10.2967/jnumed.111.101808 | DOI Listing |
Radiol Imaging Cancer
January 2025
From the Stephenson Cancer Center, University of Oklahoma Health Sciences Center, 800 NE 10th St, Oklahoma City, OK 73104 (J.H.C., L.M., S.K.V., Z.H., M.P., J.G., Y.W.); Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY (J.L., J.F.); Department of Biostatistics and Epidemiology, Hudson College of Public Health, The University of Oklahoma, Oklahoma City, Okla (S.K.V., T.G.); Experimental Transplantation and Immunotherapy Branch, National Cancer Institute, National Institutes of Health, Bethesda, Md (C.G.K., R.G.); Department of Biomedical Engineering, University of Central Oklahoma, Edmond, Okla (Z.H.); and Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Emory University, Atlanta, GA (K.M.W.).
Purpose To determine whether fluorine 18 (F) fluorothymidine (FLT) PET imaging alone or combined with Mount Sinai Acute GVHD International Consortium (MAGIC) biomarkers could help identify subclinical gastrointestinal graft versus host disease (GI-GVHD) by day 100 following hematopoietic stem cell transplantation (HSCT). Materials and Methods F-FLT PET imaging was analyzed in a prospective pilot study (ClinicalTrials.gov identifier no.
View Article and Find Full Text PDFEur J Nucl Med Mol Imaging
November 2024
Department of Nuclear Medicine, University of Bern, Bern, Switzerland.
Purpose: Radiomics has revolutionized clinical research by enabling objective measurements of imaging-derived biomarkers. However, the true potential of radiomics necessitates a comprehensive understanding of the biological basis of extracted features to serve as a clinical decision support. In this work, we propose an end-to-end framework for the in silico simulation of [F]FLT PET imaging process in Pancreatic Ductal Adenocarcinoma, accounting for the biological characterization of tissues (including perfusion and fibrosis) on tracer delivery.
View Article and Find Full Text PDFCancer Imaging
August 2024
Department of Radiology and Nuclear Medicine, University Hospital Brno, Jihlavská 20, Brno, 625 00, Czech Republic.
Background: To evaluate and compare the diagnostic power of [F]FLT-PET with ceMRI in patients with brain tumours or other focal lesions.
Methods: 121 patients with suspected brain tumour or those after brain tumour surgery were enroled in this retrospective study (61 females, 60 males, mean age 37.3 years, range 1-80 years).
J Clin Med
May 2024
Department of Investigational Cancer Therapeutics, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
: The inhibitory effects of tyrosine kinase inhibitors (TKIs) on glucose uptake through their binding to human glucose transporter-1 (GLUT-1) have been well documented. Thus, our research aimed to explore the potential impact of various TKIs of GLUT-1 on the standard [F]FDG-PET monitoring of tumor response in patients. : To achieve this, we conducted an analysis on three patients who were undergoing treatment with different TKIs and harbored actionable alterations.
View Article and Find Full Text PDFClin Nucl Med
August 2024
Department of Medical Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek, Amsterdam, The Netherlands.
Purpose: This prospective study evaluates the biodistribution of 18 F-FLT PET in patients with advanced melanoma before and after treatment with BRAF/MEK inhibitors.
Patients And Methods: Eighteen BRAF-positive unresectable stage IIIc or IV melanoma patients referred for 18 F-FLT PET/CT before (BL) and during (D14) BRAF/MEK inhibition were included. 18 F-FLT accumulation in the liver, bone marrow, blood, and muscle was quantified.
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