Purpose: To determine whether treatment response to the Aurora B kinase inhibitor, AZD1152, could be monitored early in the course of therapy by noninvasive [(18)F]-labeled fluoro-2-deoxyglucose, [(18)F]FDG, and/or 3'-deoxy-3'-[(18)F]fluorothymidine, [(18)F]FLT, PET imaging.
Experimental Design: AZD1152-treated and control HCT116 and SW620 xenograft-bearing animals were monitored for tumor size and by [(18)F]FDG, and [(18)F]FLT PET imaging. Additional studies assessed the endogenous and exogenous contributions of thymidine synthesis in the two cell lines.
Results: Both xenografts showed a significant volume-reduction to AZD1152. In contrast, [(18)F]FDG uptake did not demonstrate a treatment response. [(18)F]FLT uptake decreased to less than 20% of control values in AZD1152-treated HCT116 xenografts, whereas [(18)F]FLT uptake was near background levels in both treated and untreated SW620 xenografts. The EC(50) for AZD1152-HQPA was approximately 10 nmol/L in both SW620 and HCT116 cells; in contrast, SW620 cells were much more sensitive to methotrexate (MTX) and 5-Fluorouracil (5FU) than HCT116 cells. Immunoblot analysis demonstrated marginally lower expression of thymidine kinase in SW620 compared with HCT116 cells. The aforementioned results suggest that SW620 xenografts have a higher dependency on the de novo pathway of thymidine utilization than HCT116 xenografts.
Conclusions: AZD1152 treatment showed antitumor efficacy in both colon cancer xenografts. Although [(18)F]FDG PET was inadequate in monitoring treatment response, [(18)F]FLT PET was very effective in monitoring response in HCT116 xenografts, but not in SW620 xenografts. These observations suggest that de novo thymidine synthesis could be a limitation and confounding factor for [(18)F]FLT PET imaging and quantification of tumor proliferation, and this may apply to some clinical studies as well.
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http://dx.doi.org/10.1158/1078-0432.CCR-10-1430 | 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 Neurosurg Case Lessons
July 2024
Department of Neurological Surgery, Kagawa University Faculty of Medicine, Kita-gun, Kagawa, Japan.
Background: There is limited literature on the use of positron emission tomography (PET) for benign tumors originating in the brain ventricles, and the use of multiple tracers for subependymal giant cell astrocytoma (SEGA) has not been reported. The authors compared the PET findings in two SEGA cases with past reports and literature, exploring the distinctive characteristics of SEGA on PET.
Observations: In a 21-year-old female with SEGA, the authors utilized 18F-fluorodeoxyglucose (18F-FDG), 11C-methionine (11C-MET), 18F-fluorothymidine (18F-FLT), 18F-fluoromisonidazole, and 18F-THK5351 tracers.
Nucl Med Mol Imaging
June 2024
Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, Seoul, 03722 Republic of Korea.
Positron emission tomography/computed tomography (PET/CT) has dramatically altered the landscape of noninvasive glioma evaluation, offering complementary insights to those gained through magnetic resonance imaging (MRI). PET/CT scans enable a multifaceted analysis of glioma biology, supporting clinical applications from grading and differential diagnosis to mapping the full extent of tumors and planning subsequent treatments and evaluations. With a broad array of specialized radiotracers, researchers and clinicians can now probe various biological characteristics of gliomas, such as glucose utilization, cellular proliferation, oxygen deficiency, amino acid trafficking, and reactive astrogliosis.
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