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Abstract
The major applications for molecular imaging with PET in clinical practice concern cancer imaging. Undoubtedly, 18F-FDG represents the backbone of nuclear oncology as it remains so far the most widely employed positron emitter compound. The acquired knowledge on cancer features, however, allowed the recognition in the last decades of multiple metabolic or pathogenic pathways within the cancer cells, which stimulated the development of novel radiopharmaceuticals. An endless list of PET tracers, substantially covering all hallmarks of cancer, has entered clinical routine or is being investigated in diagnostic trials. Some of them guard significant clinical applications, whereas others mostly bear a huge potential. This chapter summarizes a selected list of non-FDG PET tracers, described based on their introduction into and impact on clinical practice.
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Wang X, Huo L. Non-18F-Fluorodeoxyglucos PET Tracers in Pediatric Disease. PET Clin 2020; 15:241-251. [DOI: 10.1016/j.cpet.2020.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Porot C, Knapp J, Wang J, Germain S, Camporese D, Seimbille Y, Boulahdour H, Vuitton DA, Gottstein B, Blagosklonov O. Development of a specific tracer for metabolic imaging of alveolar echinococcosis: A preclinical study. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:5587-90. [PMID: 25571261 DOI: 10.1109/embc.2014.6944893] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Positron emission tomography (PET)-computed tomography (CT) using [18F]-fluorodeoxyglucose (FDG) (FDG-PET/CT) is a valuable method for initial staging and follow up of patients with alveolar echinococcosis (AE). However, the cells responsible for FDG uptake have not been clearly identified. The main goal of our study was to evaluate the uptake of PET tracers by the cells involved in the host-parasite reaction around AE lesions as the first step to develop a specific PET tracer that would allow direct assessment of parasite viability in AE. Candidate molecules ([18F]-fluorotyrosine (FET), [18F]-fluorothymidine (FLT), and [18F]-fluorometylcholine (FMC), were compared to FDG by in vitro studies on human leukocytes and parasite vesicles. Our results confirmed that FDG was mainly consumed by immune cells and showed that FLT was the best candidate tracer for parasite metabolism. Indeed, parasite cells exhibited high uptake of FLT. We also performed PET/CT scans in mice infected intraperitoneally with E. multilocularis metacestodes. PET images showed no FDG or FLT uptake in parasitic lesions. This preliminary study assessed the metabolic activity of human leukocytes and AE cells using radiolabeling. Future studies could develop a specific PET tracer for AE lesions to improve lesion detection and echinococcosis treatment in patients. Our results demonstrated that a new animal model is needed for preclinical PET imaging to better mimic human hepatic and/or periparasitic metabolism.
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Wardak M, Schiepers C, Cloughesy TF, Dahlbom M, Phelps ME, Huang SC. ¹⁸F-FLT and ¹⁸F-FDOPA PET kinetics in recurrent brain tumors. Eur J Nucl Med Mol Imaging 2014; 41:1199-209. [PMID: 24604590 DOI: 10.1007/s00259-013-2678-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 12/20/2013] [Indexed: 11/25/2022]
Abstract
PURPOSE In this study, kinetic parameters of the cellular proliferation tracer (18)F-3'-deoxy-3'-fluoro-L-thymidine (FLT) and the amino acid probe 3,4-dihydroxy-6-(18)F-fluoro-L-phenylalanine (FDOPA) were measured before and early after the start of therapy, and were used to predict the overall survival (OS) of patients with recurrent malignant glioma using multiple linear regression (MLR) analysis. METHODS High-grade recurrent brain tumors in 21 patients (11 men and 10 women, age range 26 - 76 years) were investigated. Each patient had three dynamic PET studies with each probe: at baseline and after 2 and 6 weeks from the start of treatment. Treatment consisted of biweekly cycles of bevacizumab (an angiogenesis inhibitor) and irinotecan (a chemotherapeutic agent). For each study, about 3.5 mCi of FLT (or FDOPA) was administered intravenously and dynamic PET images were acquired for 1 h (or 35 min for FDOPA). A total of 126 PET scans were analyzed. A three-compartment, two-tissue model was applied to estimate tumor FLT and FDOPA kinetic rate constants using a metabolite- and partial volume-corrected input function. MLR analysis was used to model OS as a function of FLT and FDOPA kinetic parameters for each of the three studies as well as their relative changes between studies. An exhaustive search of MLR models using three or fewer predictor variables was performed to find the best models. RESULTS Kinetic parameters from FLT were more predictive of OS than those from FDOPA. The three-predictor MLR model derived using information from both probes (adjusted R(2) = 0.83) fitted the OS data better than that derived using information from FDOPA alone (adjusted R(2) = 0.41), but was only marginally different from that derived using information from FLT alone (adjusted R(2) = 0.82). Standardized uptake values (either from FLT alone, FDOPA alone, or both together) gave inferior predictive results (best adjusted R(2) = 0.25). CONCLUSION For recurrent malignant glioma treated with bevacizumab and irinotecan, FLT kinetic parameters obtained early after the start of treatment (absolute values and their associated changes) can provide sufficient information to predict OS with reasonable confidence using MLR. The slight increase in accuracy for predicting OS with a combination of FLT and FDOPA PET information may not warrant the additional acquisition of FDOPA PET for therapy monitoring in patients with recurrent glioma.
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Affiliation(s)
- Mirwais Wardak
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave, Los Angeles, CA, 90095-6948, USA
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Abstract
The major application for PET imaging in clinical practice is represented by cancer imaging and (18)F-FDG is the most widely employed positron emitter compound. However, some diseases cannot be properly evaluated with this tracer and thus there is the necessity to develop more specific compounds. The last decades were a continuous factory for new radiopharmaceuticals leading to an endless list of PET tracers; however, just some of them guard diagnostic relevance in routine medical practice. This chapter describes a selected list of non-FDG PET tracers, basing on their introduction into and impact on clinical practice.
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Affiliation(s)
- Egesta Lopci
- Nuclear Medicine Unit, Humanitas Cancer Center, Rozzano, MI, Italy
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Han D, Yu J, Zhong X, Fu Z, Mu D, Zhang B, Xu G, Yang W, Zhao S. Comparison of the diagnostic value of 3-deoxy-3-18F-fluorothymidine and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in the assessment of regional lymph node in thoracic esophageal squamous cell carcinoma: a pilot study. Dis Esophagus 2012; 25:416-26. [PMID: 21951837 DOI: 10.1111/j.1442-2050.2011.01259.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We used pathological examination as golden standard to determine whether 3-deoxy-3-(18)F-fluorothymidine positron emission tomography/computed tomography (FLT PET/CT) can detect regional lymph node metastasis in untreated thoracic esophageal squamous cell carcinoma and additionally performed (18)F-fluorodeoxyglucose (FDG) PET/CT for direct comparison with that of FLT. Twenty-two patients with thoracic esophageal squamous cell carcinoma underwent dual-tracer PET/CT examinations before surgery. The results of reviewing CT images and side-by-side FDG PET and FLT PET images for the diagnosis of locoregional lymph node metastasis were compared prospectively in relation to pathologic findings. All patients underwent esophagectomy and lymphadenectomy. Pathologic examination confirmed nodes positive for metastasis in 16 patients and 47 of 424 excised nodes. The uptake of FDG (median SUVmax, 5.4; range, 2.4-10.6) in locoregional lymph nodes metastases was significantly higher than that of FLT (median SUVmax, 2.8; range, 1.3-4.6). There were 14 false-positive nodes in FDG PET/CT and only 3 in FLT PET/CT; 8 false-negative nodes in FDG PET/CT, while there were 12 false negative nodes in FLT PET/CT. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FLT PET/CT were 74.47%, 99.20%, 96.46%, 92.11%, and 96.89%, respectively, whereas those of FDG PET/CT were 82.98%, 96.29%, 94.81%, 82.98%, and 96.29%, respectively. P-values were 0.450, 0.014, 0.313, 0.050, and 0.555, respectively. FLT uptake in regional lymph nodes of esophageal carcinoma is significantly lower compared with FDG uptake. FLT PET/CT has fewer false-positive findings and higher specificity compared with FDG PET/CT.
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Affiliation(s)
- D Han
- Departments of Radiation Oncology, Shandong Cancer Hospital and Institute Shandong Province Key Laboratory of Radiation Oncology, Jinan, China
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Soloviev D, Lewis D, Honess D, Aboagye E. [(18)F]FLT: an imaging biomarker of tumour proliferation for assessment of tumour response to treatment. Eur J Cancer 2012; 48:416-24. [PMID: 22209266 DOI: 10.1016/j.ejca.2011.11.035] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 11/27/2011] [Indexed: 01/13/2023]
Abstract
The paradigm of drug development is shifting towards early use of imaging biomarkers as surrogate end-points in clinical trials. Quantitative Imaging in Cancer: Connecting Cellular Processes (QuIC-ConCePT) is an initiative to qualify complementary imaging biomarkers (IB) of proliferation, cell death and tumour heterogeneity as possible tools in early phase clinical trials to help pharmaceutical developers in 'go, no-go' decisions early in the process of drug development. One of the IBs is [(18)F]3'-deoxy-3'-fluorothymidine with Positron Emission Tomography (FLT-PET). We review results of recent clinical trials using FLT-PET for monitoring tumour response to drug treatment and discuss the potential and the possible pitfalls of using this IB as a surrogate end-point in early phase clinical trials for assessing tumour response to drug treatment. From first human trial results it seems that the degree of FLT accumulation in tumours is governed not only by the tumour proliferation rate but also by other factors. Nevertheless FLT-PET could potentially be used as a negative predictor of tumour response to chemotherapy, and hence evaluation of this IB is granted in multi-centre clinical trials.
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Affiliation(s)
- Dmitry Soloviev
- Cancer Research UK, Cambridge Research Institute, Cambridge CB2 0RE, UK.
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Kong FL, Kim EE, Yang DJ. Targeted nuclear imaging of breast cancer: status of radiotracer development and clinical applications. Cancer Biother Radiopharm 2011; 27:105-12. [PMID: 21877909 DOI: 10.1089/cbr.2011.1025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Breast cancer is the most common cancer in women worldwide. Molecular imaging plays an important role in breast cancer diagnosis, staging, and treatment response evaluation. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are the main clinical molecular imaging modalities that are based on the detection of radiotracers. This article discusses the typical radiotracers used for breast cancer imaging by PET and SPECT. In addition, radiotracers that are currently applied for human breast cancer imaging or under clinical trials are also reviewed in compliance with the categories of tumor-specific targets to which they are aimed at.
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Affiliation(s)
- Fan-Lin Kong
- Department of Experimental Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, 77030, USA.
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Lee SJ, Kang HY, Kim SY, Chung JH, Oh SJ, Ryu JS, Kim SB, Kang JS, Park SK, Kim HM, Kim MH, Moon DH. Early assessment of tumor response to JAC106, an anti-tubulin agent, by 3′-deoxy-3′-[18F]fluorothymidine in preclinical tumor models. Eur J Nucl Med Mol Imaging 2011; 38:1436-48. [DOI: 10.1007/s00259-011-1802-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 03/09/2011] [Indexed: 10/18/2022]
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Xu B, Guan Z, Liu C, Wang R, Yin D, Zhang J, Chen Y, Yao S, Shao M, Wang H, Tian J. Can multimodality imaging using 18F-FDG/18F-FLT PET/CT benefit the diagnosis and management of patients with pulmonary lesions? Eur J Nucl Med Mol Imaging 2010; 38:285-92. [DOI: 10.1007/s00259-010-1625-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 09/09/2010] [Indexed: 10/19/2022]
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Sauter AW, Wehrl HF, Kolb A, Judenhofer MS, Pichler BJ. Combined PET/MRI: one step further in multimodality imaging. Trends Mol Med 2010; 16:508-15. [PMID: 20851684 DOI: 10.1016/j.molmed.2010.08.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 08/17/2010] [Accepted: 08/18/2010] [Indexed: 12/11/2022]
Abstract
Given the need for sophisticated in vivo detection techniques to better characterize the cellular and subcellular processes in animals and humans, molecular imaging has become an important discipline. Techniques in molecular imaging have developed from stand alone modalities to multimodality methods. Among these, the combination of positron emission tomography (PET) and computed tomography (CT) is a successful imaging method and has become an important tool in clinical practice. Technological approaches that combine magnetic resonance imaging (MRI) with diffuse optical tomography (DOT), fluorescence tomography (FT) and PET have now been introduced. PET/MRI and the resulting combination of molecular, morphological and functional information will pave the way for a better understanding of physiological and disease mechanisms in preclinical and clinical settings.
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Affiliation(s)
- Alexander W Sauter
- University of Tuebingen, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens-Foundation, Roentgenweg 13, 72076 Tuebingen, Germany
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Michalski MH, Chen X. Molecular imaging in cancer treatment. Eur J Nucl Med Mol Imaging 2010; 38:358-77. [PMID: 20661557 DOI: 10.1007/s00259-010-1569-z] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 07/12/2010] [Indexed: 12/19/2022]
Abstract
The success of cancer therapy can be difficult to predict, as its efficacy is often predicated upon characteristics of the cancer, treatment, and individual that are not fully understood or are difficult to ascertain. Monitoring the response of disease to treatment is therefore essential and has traditionally been characterized by changes in tumor volume. However, in many instances, this singular measure is insufficient for predicting treatment effects on patient survival. Molecular imaging allows repeated in vivo measurement of many critical molecular features of neoplasm, such as metabolism, proliferation, angiogenesis, hypoxia, and apoptosis, which can be employed for monitoring therapeutic response. In this review, we examine the current methods for evaluating response to treatment and provide an overview of emerging PET molecular imaging methods that will help guide future cancer therapies.
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Guo N, Xie J, Manning HC, Deane NG, Ansari MS, Coffey RJ, Gore J, Price RR, Baldwin RM, McIntyre JO. A novel in vitro assay to assess phosphorylation of 3'-[(18)F]fluoro-3'-deoxythymidine. Mol Imaging Biol 2010; 13:257-64. [PMID: 20532643 DOI: 10.1007/s11307-010-0351-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PURPOSE 3'-[(18)F]fluoro-3'-deoxythymidine ([(18)F]FLT) is phosphorylated by thymidine kinase 1 (TK-1), a cell cycle regulated enzyme. Appropriate use of [(18)F]FLT tracer requires validation of the TK-1 activity. Here, we report development of a novel phosphoryl-transfer assay to assess phosphorylation of [(18)F]FLT both in tumor cell lysates and tumor cells. PROCEDURES The intrinsic F-18 radioactivity was used to quantify both substrate and phosphorylated products using a rapid thin layer chromatography method. Phosphorylation kinetics of [(18)F]FLT in SW480 and DiFi tumor cell lysates and cellular uptake were measured. RESULTS The apparent Michaelis-Menten kinetic parameters for [(18)F]FLT are K(m) = 4.8 ± 0.3 μM and V(max) = 7.4 pmol min(-1) per 1 × 10(6) cells with ~2-fold higher TK-1 activity in DiFi versus SW480 lysates. CONCLUSIONS The apparent K (m) of [(18)F]FLT was comparable to the value reported with purified recombinant TK-1. The uptake of [(18)F]FLT by SW480 cells is inhibited by nitrobenzylthioinosine or dipyridamole indicating that uptake is mediated predominantly by the equilibrative nucleoside transporters in these tumor cells.
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Affiliation(s)
- Ning Guo
- Department of Radiology and Radiological Sciences, Vanderbilt University School of Medicine, 1161 21st Avenue South, Nashville, TN 37232, USA.
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Zhang S, Wang X, He Y, Ding R, Liu H, Xu J, Feng M, Li G, Wang M, Peng C, Qi C. (18)F Labeled benzimidazole derivatives as potential radiotracer for positron emission tomography (PET) tumor imaging. Bioorg Med Chem 2010; 18:2394-401. [PMID: 20303769 DOI: 10.1016/j.bmc.2010.02.060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 02/25/2010] [Accepted: 02/26/2010] [Indexed: 10/19/2022]
Abstract
This article reported the synthesis and bioevaluation of two [(18)F] labeled benzimidazole derivatives, 4-(5-(2-[(18)F] fluoro-4-nitrobenzamido)-1-methyl-1H-benzimidazol-2-yl) butanoic acid ([(18)F] FNBMBBA, [(18)F]a1) and 3-(2-fluoroethyl)-7-methyl-2-propyl-3H-benzimidazole-5-carboxylic acid ([(18)F] FEMPBBA, [(18)F]b1) for PET tumor imaging. The preparation [(18)F] FEMPBBA was completed in 1h with overall radiochemical yield of 50-60% (without decay corrected). Biodistribution assay in S180 tumor bearing mice of both compounds were carried out, and the results are both meaningful. [(18)F] FEMPBBA which can be taken as a revision of [(18)F] FNBMBBA got an excellent result, and has significant advantages in some aspects compared with L-[(18)F] FET and [(18)F]-FDG in the same animal model, especially in tumor/brain uptake ratio. The tumor/brain uptake ratio of [(18)F] FEMPBBA gets to 4.81, 7.15, and 9.8 at 30min, 60min and 120min, and is much higher than that of L-[(18)F] FET (2.54, 2.92 and 2.95) and [(18)F]-FDG (0.61, 1.02, 1.33) at the same time point. The tumor/muscle and tumor/blood uptake ratio of [(18)F] FEMPBBA is also higher than that of L-[(18)F] FET at 30min and 60min. This result indicates compound [(18)F] FEMPBBA is a promising radiotracer for PET tumor imaging.
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Affiliation(s)
- Shuting Zhang
- Key laboratory of Radiopharmaceuticals, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
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Yang W, Zhang Y, Fu Z, Yu J, Sun X, Mu D, Han A. Imaging of proliferation with 18F-FLT PET/CT versus 18F-FDG PET/CT in non-small-cell lung cancer. Eur J Nucl Med Mol Imaging 2010; 37:1291-9. [PMID: 20309686 DOI: 10.1007/s00259-010-1412-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Accepted: 02/05/2010] [Indexed: 01/21/2023]
Abstract
PURPOSE To compare the diagnostic efficacies of (18)F-FLT and (18)F-FDG PET/CT in non-small-cell lung cancer (NSCLC), focusing on the correlation between FLT and FDG tumour uptake and tumour cell proliferation as indicated by the cyclin D1 labelling index. METHODS A total of 31 patients with NSCLC underwent FLT and FDG PET/CT scanning followed by surgery. PET/CT images were compared with the pathology. Tumour cell proliferation was assessed by cyclin D1 immunohistochemistry. RESULTS The sensitivities of FLT and FDG PET/CT for the primary lesion were 74% and 94%, respectively (p=0.031). For N staging, 77% patients were correctly staged, 6% overstaged, 16% understaged by FLT, while the values for FDG were 77%, 16% and 6%, respectively. The sensitivity, specificity, accuracy, and positive predictive value with FLT for lymph nodes were 65%, 98%, 93% and 89%, respectively, and 85%, 84%, 84% and 52% with FDG (p<0.01).Tumour SUV of FLT was significantly correlated with the cyclin D1 labelling index (r=0.644; p<0.01), but the SUV of FDG was not significantly correlated (r=0.293; p>0.05). CONCLUSION In terms of N staging, FLT PET/CT resulted in understaging of more patients but overstaging of fewer patients, and for regional lymph nodes showed better specificity, accuracy and positive predictive value than FDG PET/CT in NSCLC. Tumour FLT uptake was correlated with tumour cell proliferation as indicated by the cyclin D1 labelling index, suggesting that further studies are needed to evaluate the use of FLT PET/CT for the assessment of therapy response to anticancer drugs.
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Affiliation(s)
- Wenfeng Yang
- Department of Thoracic Surgery, Shandong Cancer Hospital and Institute, Jinan, 250117, Shandong Province, People's Republic of China
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Molecular PET and PET/CT imaging of tumour cell proliferation using F-18 fluoro-L-thymidine: a comprehensive evaluation. Nucl Med Commun 2010; 30:908-17. [PMID: 19794320 DOI: 10.1097/mnm.0b013e32832ee93b] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Positron emission tomography (PET) using F-18 fluoro-3'-deoxy-3-L-fluorothymidine (FLT) offers noninvasive assessment of cell proliferation in vivo. The most important application refers to the evaluation of tumour proliferative activity, representing a key feature of malignancy. Most data to date suggest that FLT is not a suitable biomarker for staging of cancers. This is because of the rather low fraction of tumour cells that undergo replication at a given time with subsequently relatively low tumour FLT uptake. In addition, generally, the high FLT uptake in liver and bone marrow limits the diagnostic use. We describe the current status on preclinical and clinical applications of FLT-PET including our own experience in brain tumours. The future of FLT-PET probably lies in the evaluation of tumour response to therapy and more importantly, in the prediction of early response in the course of treatment. The level of FLT accumulation in tumours depends on thymidine kinase 1 activity and on the therapy-induced activation of the salvage pathway and expression of nucleoside transporters. Therefore, cytostatic agents that cause arrest of the cell cycle in the S-phase may initially increase FLT uptake rather than reducing the tumour cell accumulation. In addition, agents that block the endogenous thymidine pathway may lead to overactivity of the salvage pathway and increase tumour FLT uptake. In contrast, many therapeutic agents inhibit both pathways and subsequently reduce tumour FLT uptake. Further studies comparing FLT with F-18 fluorodeoxyglucose-PET will be important to determine the complementary advantage of FLT-PET in early cancer therapy response assessment. Further research should be facilitated by simplified synthesis of FLT with improved yields and an increasing commercial availability.
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Choi SJ, Kim SY, Kim SJ, Lee JS, Lee SJ, Park SA, Lee SJ, Yun SC, Im KC, Oh SJ, Kim SW, Kim JS, Ryu JS, Moon DH. Reproducibility of the kinetic analysis of 3′-deoxy-3′-[18F]fluorothymidine positron emission tomography in mouse tumor models. Nucl Med Biol 2009; 36:711-9. [DOI: 10.1016/j.nucmedbio.2009.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 03/27/2009] [Accepted: 06/14/2009] [Indexed: 11/26/2022]
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Tian J, Yang X, Yu L, Chen P, Xin J, Ma L, Feng H, Tan Y, Zhao Z, Wu W. A Multicenter Clinical Trial on the Diagnostic Value of Dual-Tracer PET/CT in Pulmonary Lesions Using 3′-Deoxy-3′-18F-Fluorothymidine and 18F-FDG. J Nucl Med 2008; 49:186-94. [DOI: 10.2967/jnumed.107.044966] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Suehiro M, Vallabhajosula S, Goldsmith SJ, Ballon DJ. Investigation of the role of the base in the synthesis of [18F]FLT. Appl Radiat Isot 2007; 65:1350-8. [DOI: 10.1016/j.apradiso.2007.07.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Revised: 06/04/2007] [Accepted: 07/09/2007] [Indexed: 11/16/2022]
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Abstract
PET is an exquisitely sensitive molecular imaging technique using positron-emitting radioisotopes coupled to specific ligands. Many biological targets of great interest can be imaged with these radiolabelled ligands. This review describes the current status of non-18-fluorodeoxyglucose PET tracers that have a potential clinical effect in oncology. With the help of these tracers, knowledge is being acquired on the molecular characterisation of specific tumours, their biological signature, and postinterventional response. The potential role of these imaging probes for tumour detection and monitoring is progressively being recognised by clinical oncologists, biologists, and pharmacologists.
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Affiliation(s)
- Ashley M Groves
- Institute of Nuclear Medicine, University College London, London, UK.
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Kumar R. Assessment of therapy response in malignant tumours with 18F-fluorothymidine. Eur J Nucl Med Mol Imaging 2007; 34:1334-8. [PMID: 17479261 DOI: 10.1007/s00259-007-0446-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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