Displaying publications 1 - 20 of 110 in total

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  1. May IJ, Nowak AK, Francis RJ, Ebert MA, Dhaliwal SS
    J Med Imaging Radiat Oncol, 2024 Feb;68(1):57-66.
    PMID: 37898984 DOI: 10.1111/1754-9485.13592
    INTRODUCTION: Malignant pleural mesothelioma is difficult to prognosticate. F18-Fluorodeoxyglucose positron emission tomography (FDG PET) shows promise for response assessment but is confounded by talc pleurodesis. F18-Fluorothymidine (FLT) PET is an alternative tracer specific for proliferation. We compared the prognostic value of FDG and FLT PET and determined the influence of talc pleurodesis on these parameters.

    METHODS: Overall, 29 prospectively recruited patients had FLT PET, FDG PET and CT-scans performed prior to and post one chemotherapy cycle; 10 had prior talc pleurodesis. Patients were followed for overall survival. CT response was assessed using mRECIST. Radiomic features were extracted using the MiM software platform. Changes in maximum SUV (SUVmax), mean SUV (SUVmean), FDG total lesion glycolysis (TLG), FLT total lesion proliferation (TLP) and metabolic tumour volume (MTV) after one chemotherapy cycle.

    RESULTS: Cox univariate analysis demonstrated FDG PET radiomics were confounded by talc pleurodesis, and that percentage change in FLT MTV was predictive of overall survival. Cox multivariate analysis showed a 10% increase in FLT tumour volume corresponded with 9.5% worsened odds for overall survival (P = 0.028, HR = 1.095, 95% CI [1.010, 1.187]). No other variables were significant on multivariate analysis.

    CONCLUSION: This is the first prospective study showing the statistical significance of FLT PET tumour volumes for measuring mesothelioma treatment response. FLT may be better than FDG for monitoring mesothelioma treatment response, which could help optimise mesothelioma treatment regimes.

    Matched MeSH terms: Positron-Emission Tomography/methods; Positron Emission Tomography Computed Tomography/methods
  2. Robson RE, Brunger MJ, Buckman SJ, Garcia G, Petrović ZLj, White RD
    Sci Rep, 2015 Aug 06;5:12674.
    PMID: 26246002 DOI: 10.1038/srep12674
    The kinetic theory of non-relativistic positrons in an idealized positron emission tomography PET environment is developed by solving the Boltzmann equation, allowing for coherent and incoherent elastic, inelastic, ionizing and annihilating collisions through positronium formation. An analytic expression is obtained for the positronium formation rate, as a function of distance from a spherical source, in terms of the solutions of the general kinetic eigenvalue problem. Numerical estimates of the positron range - a fundamental limitation on the accuracy of PET, are given for positrons in a model of liquid water, a surrogate for human tissue. Comparisons are made with the 'gas-phase' assumption used in current models in which coherent scattering is suppressed. Our results show that this assumption leads to an error of the order of a factor of approximately 2, emphasizing the need to accurately account for the structure of the medium in PET simulations.
    Matched MeSH terms: Positron-Emission Tomography/methods*
  3. Mahmud MH, Nordin AJ, Ahmad Saad FF, Azman AZ
    Quant Imaging Med Surg, 2015 Oct;5(5):700-7.
    PMID: 26682140 DOI: 10.3978/j.issn.2223-4292.2015.05.02
    Increased metabolic activity of fluorodeoxyglucose (FDG) in tissue is not only resulting of pathological uptake, but due to physiological uptake as well. This study aimed to determine the impacts of biological and procedural factors on FDG uptake of liver in whole body positron emission tomography/computed tomography (PET/CT) imaging.
    Matched MeSH terms: Positron-Emission Tomography; Positron Emission Tomography Computed Tomography
  4. Joshi SC, Pant I, Hamzah F, Kumar G, Shukla AN
    Indian J Cancer, 2008 12 30;45(4):137-41.
    PMID: 19112200
    Positron emission tomography (PET) has emerged as an important diagnostic tool in the management of lung cancers. Although PET is sensitive in detection of lung cancer, but FDG (2-deoxy-2- 18 fluro-D-glucose) is not tumor specific and may accumulate in a variety of nonmalignant conditions occasionally giving false positive result. Addition of CT to PET improves specificity foremost, but also sensitivity in tumor imaging. Thus, PET/CT fusion images are a more accurate test than either of its individual components and are probably also better than side-by-side viewing of images from both modalities. PET/CT fusion images are useful in differentiating between malignant and benign disease, fibrosis and recurrence, staging and in changing patient management to more appropriate therapy. With analysis and discussion it appears that PET/ CT fusion images have the potential to dramatically improve our ability to manage the patients with lung cancer and is contributing to our understanding of cancer cell biology and in development of new therapies.
    Matched MeSH terms: Positron-Emission Tomography/methods*; Positron-Emission Tomography/trends
  5. Ahmad Sarji S
    Biomed Imaging Interv J, 2006 Oct;2(4):e59.
    PMID: 21614339 MyJurnal DOI: 10.2349/biij.2.4.e59
    Many potential pitfalls and artefacts have been described in PET imaging that uses F-18 fluorodeoxyglucose (FDG). Normal uptake of FDG occurs in many sites of the body and may cause confusion in interpretation particularly in oncology imaging. Clinical correlation, awareness of the areas of normal uptake of FDG in the body and knowledge of variation in uptake as well as benign processes that are FDG avid are necessary to avoid potential pitfalls in image interpretation. In this context, optimum preparation of patients for their scans can be instituted in an attempt to reduce the problem. Many of the problems and pitfalls associated with areas of normal uptake of FDG can be solved by using PET CT imaging. PET CT imaging has the ability to correctly attribute FDG activity to a structurally normal organ on CT. However, the development of combined PET CT scanners also comes with its own specific problems related to the combined PET CT technique. These include misregistration artefacts due to respiration and the presence of high density substances which may lead to artefactual overestimation of activity if CT data are used for attenuation correction.
    Matched MeSH terms: Positron-Emission Tomography; Positron Emission Tomography Computed Tomography
  6. Ren X, Nur Salihin Yusoff M, Hartini Mohd Taib N, Zhang L, Wang K
    Eur J Radiol, 2024 Jan;170:111274.
    PMID: 38147764 DOI: 10.1016/j.ejrad.2023.111274
    PURPOSE: The goal of this study was to evaluate the effectiveness of two diagnostic methods, 68Ga-PSMA-11 PET/CT and mpMRI, in detecting primary prostate cancer without limitations on the Gleason score.

    METHODS: We conducted a comprehensive literature review, searching databases such as PubMed, Embase, and Web of Science until June 2023. Our objective was to identify studies that compared the efficacy of 68Ga-PSMA-11 PET/CT and mpMRI in detecting primary prostate cancer. To determine heterogeneity, the I2 statistic was used. Meta-regression analysis and leave-one-out sensitivity analysis were conducted to identify potential sources of heterogeneity.

    RESULTS: Initially, 1286 publications were found, but after careful evaluation, only 16 studies involving 1227 patients were analyzed thoroughly. The results showed that the 68Ga-PSMA-11 PET/CT method had a pooled sensitivity and specificity of 0.87 (95 % CI: 0.80-0.92) and 0.80 (95 % CI: 0.69-0.89), respectively, for diagnosing prostatic cancer. Similarly, the values for mpMRI were determined as 0.84 (95 % CI: 0.75-0.92) and 0.74 (95 % CI: 0.61-0.86), respectively. There were no significant differences in diagnostic effectiveness observed when comparing two primary prostate cancer methodologies (pooled sensitivity P = 0.62, pooled specificity P = 0.50). Despite this, the funnel plots showed symmetry and the Egger test results (P values > 0.05) suggested there was no publication bias.

    CONCLUSIONS: After an extensive meta-analysis, it was found that both 68Ga-PSMA-11 PET/CT and mpMRI demonstrate similar diagnostic effectiveness in detecting primary prostate cancer. Future larger prospective studies are warranted to investigate this issue further.

    Matched MeSH terms: Positron Emission Tomography Computed Tomography/methods
  7. Chan K, Ghani DAM, Teoh J, Brodie A, Gan C, Foley C, et al.
    Urol Oncol, 2024 Dec;42(12):421-428.
    PMID: 39299895 DOI: 10.1016/j.urolonc.2024.08.019
    Conventionally, transrectal ultrasound guided prostate biopsy (TRUS-Bx) was the main technique used for the diagnosis of prostate cancer since it was first described in 1989 [1]. However, the PROMIS trial showed that this random, nontargeted approach could miss up to 18% of clinically significant cancer (csPCa) [2]. Furthermore, risk of sepsis post TRUS-Bx can be as high as 2.4% [3]. Understanding the demerits of TR-biopsy have led to the introduction of transperineal prostate biopsy (TP-Bx). The incorporation of mpMRI revolutionized prostate cancer diagnostics, allowing visualization of areas likely to harbor csPCa whilst permitting some men to avoid an immediate biopsy. Furthermore, the advent of prostate specific membrane antigen-positron emission tomography (PSMA-PET) is highly promising, because of its role in primary diagnosis of prostate cancer and its higher diagnostic accuracy over conventional imaging in detecting nodal and metastatic lesions. Our narrative review provides an overview on prostate biopsy techniques and an update on prostate imaging, with particular focus on PSMA-PET.
    Matched MeSH terms: Positron-Emission Tomography/methods
  8. Rukiah A. Latiff, Akmal Sabaruddin, Norfadilah Mat Nor
    MyJurnal
    Thyroid and gonads are radiosensitive organs which requires radiation shield to reduce the dose received. However,
    radiation shielding is not widely used in radionuclide imaging because it is heavy, uncomfortable and can cause pain
    in the spine. Therefore, a research was carried out to determine the ability of thyroid and gonad radiation shield
    which is thinner and lighter in reducing radiation dose. A study was conducted in Hospital Putrajaya to determine
    the radiation dose received by the thyroid and gonads during a complete Positron Emission Tomography-Computed
    Tomography (PET-CT) procedure with and without radiation shield. A total of six male staffs have been chosen as subject
    and data from 33 complete PET-CT procedures have been collected. For every PET-CT procedure, the subject’s thyroid
    and gonad were shielded using 0.5-mm thick radiation shielded, model Mavig 615 (USA) and Shielding International
    (USA) respectively. Thermal luminescent dosimeter (TLD) chips were used as radiation dose detector. The average 18FFDG radioactivity administered to the patient was 387 MBq and the average scan time is 9.224 ± 1.797 minutes. The
    results showed that the mean equivalent dose received by the thyroid with and without shielding were 0.080 ± 0.033
    mSv and 0.078 ± 0.039 mSv respectively. The mean equivalent dose received by gonad with and without shielding
    were 0.059 ± 0.040 mSv and 0.061 ± 0.030 mSv respectively. Radiation shield with 0.5 mm thickness is unable to
    reduce radiation dose received by the thyroid (p = 0.76) and gonads (p = 0.79) because it is too thin to resist the
    high-energy radiation during PET-CT procedures. Thyroid receive higher radiation dose of 0.016 m Sv compared to
    the gonads (p < 0.05) because the thyroid’s position is more exposed to radiation sources which are 18F-FDG during
    radiopharmaceutical preparation and patients after administered with 18F-FDG during PET-CT procedure.
    Keywords: equivalent dose, radiation shield, TLD
    Matched MeSH terms: Positron-Emission Tomography
  9. Thientunyakit T, Sethanandha C, Muangpaisan W, Minoshima S
    Med J Malaysia, 2021 07;76(4):493-501.
    PMID: 34305110
    INTRODUCTION: The aim of this study is to use 3D-SSP and a population-comparable normal database to investigate the associations between amyloid deposition detected by 18Fflorbetapir PET and neurocognitive performance of participants with mild cognitive impairment (MCI) and Alzheimer's disease (AD).

    MATERIALS AND METHODS: 18F-florbetapir PET and 18F-FDG PET imaging was prospectively performed on 78 subjects (20 cognitively healthy controls [HC], 27 MCI patients, and 31 AD patients) within 6 weeks of their neurocognitive assessments. The PET datasets from 19 HCs were used to create an NBD. The 3D-SSP analysis and Z-score mapping of 18F-florbetapir accumulations in the brain were further staged based on their accumulation patterns. Global and regional standard uptake value ratios (SUVRs) of 18Fflorbetapir were calculated using the cerebellar cortex as the normalised region. The relationships between the 18Fflorbetapir PET results, the clinical diagnoses and Thai Mini- Mental State Examination (TMSE) scores were determined.

    RESULTS: There was high agreement between the visual assessment results and the semiquantitative analysis (κ = 0.793 and 0.845). The stages of amyloid deposition were consistent with neurocognitive status across participants. Significantly higher SUVRs were found in AD than MCI and HC. Visual assessment and stage were not significantly correlated with TMSE scores. A significant negative correlation between the SUVRs and TMSE scores was partially demonstrated in MCI and AD, but not HC.

    CONCLUSIONS: 3D-SSP analysis of 18F-florbetapir PET provides special patterns and intensity of beta amyloid accumulation semi-quantitatively that are associated with the diagnosis and neurocognitive performances in MCI and AD patients.

    Matched MeSH terms: Positron-Emission Tomography
  10. Tan HY, Wong YH, Kasbollah A, Md Shah MN, Perkins AC, Yeong CH
    Nucl Med Commun, 2023 Apr 01;44(4):227-243.
    PMID: 36808108 DOI: 10.1097/MNM.0000000000001665
    Personalised cancer treatment is of growing importance and can be achieved via targeted radionuclide therapy. Radionuclides with theranostic properties are proving to be clinically effective and are widely used because diagnostic imaging and therapy can be accomplished using a single formulation that avoids additional procedures and unnecessary radiation burden to the patient. For diagnostic imaging, single photon emission computed tomography (SPECT) or positron emission tomography (PET) is used to obtain functional information noninvasively by detecting the gamma (γ) rays emitted from the radionuclide. For therapeutics, high linear energy transfer (LET) radiations such as alpha (α), beta (β - ) or Auger electrons are used to kill cancerous cells in close proximity, whereas sparing the normal tissues surrounding the malignant tumour cells. One of the most important factors that lead to the sustainable development of nuclear medicine is the availability of functional radiopharmaceuticals. Nuclear research reactors play a vital role in the production of medical radionuclides for incorporation into clinical radiopharmaceuticals. The disruption of medical radionuclide supplies in recent years has highlighted the importance of ongoing research reactor operation. This article reviews the current status of operational nuclear research reactors in the Asia-Pacific region that have the potential for medical radionuclide production. It also discusses the different types of nuclear research reactors, their operating power, and the effects of thermal neutron flux in producing desirable radionuclides with high specific activity for clinical applications.
    Matched MeSH terms: Positron-Emission Tomography
  11. Dureja S, McDonnell M, Van Genechten D, Bouvier C, Kolarova T, O'Toole D, et al.
    J Neuroendocrinol, 2023 Jun;35(6):e13310.
    PMID: 37351944 DOI: 10.1111/jne.13310
    SCAN, an online survey, measured access to diagnosis, treatments and monitoring of neuroendocrine tumor (NET) patients globally. Between September and November 2019, NET patients and healthcare professionals (HCPs) completed an online, semi-standardized survey with 54 patient questions and 33 HCP questions. A total of 2359 patients with NETs and 436 HCPs responded. Misdiagnosis was common (44% [1043/2359]). Mean time to diagnosis was 4.8 years (standard deviation [SD], 6.2). Compared with global figures (60% [1407/2359]), the availability of 68 Ga-DOTA positron emission tomography (PET)/computed tomography (CT) was significantly lower in Asia (45% [126/280]) and higher in Oceania (86% [171/200]). HCPs reported that 68 Ga-DOTA PET/CT was free/affordable to fewer patients in Emerging and Developing Economies (EDE) than Advanced Economies (AE; 17% [26/150] and 59% [84/142], respectively). Compared with global data (52% [1234/2359]), patient-reported availability of peptide receptor radionuclide therapy (PRRT) was significantly lower in Asia (31% [88/280]) and higher in Oceania (61% [122/200]). Significant differences were observed in average annual NET specialist costs between AE and EDE ($1081 and $2915, respectively). Compared with AE, patients in EDE traveled further for NET specialists (1032 [SD, 1578] and 181 [SD, 496] km, respectively). Patients and HCPs both recommended referral to HCPs that were more knowledgeable in the field of NETs and had better access to NET experts/specialist centers. National care pathways, enhancing HCP NET knowledge and ensuring effective diagnostics and access to appropriate treatments are crucial to improving patient survival and NET care worldwide.
    Matched MeSH terms: Positron Emission Tomography Computed Tomography
  12. Fathinul Fikri A, Lau W
    Biomed Imaging Interv J, 2010 10 01;6(4):e37.
    PMID: 21611073 DOI: 10.2349/biij.6.4.e37
    An incidental finding of an intense focus of (18)F-Fluorodeoxyglucose (FDG) pulmonary uptake on positron emission tomography (PET) without detectable lesions on computed tomography (CT) is highly suggestive of FDG microembolus. Its microscopic nature means it is undetectable on CT. It is an artefact attributable to (18)F-FDG-tracer contamination at the injection site. This paper reports a case of a 61 year-old lady with a past history of breast carcinoma, in whom follow-up PET/CT images demonstrated an incidental intense FDG pulmonary abnormality. A follow-up PET/CT seven months later demonstrated complete resolution of the abnormality.
    Matched MeSH terms: Positron-Emission Tomography; Positron Emission Tomography Computed Tomography
  13. Tooyama I, Yanagisawa D, Taguchi H, Kato T, Hirao K, Shirai N, et al.
    Ageing Res Rev, 2016 09;30:85-94.
    PMID: 26772439 DOI: 10.1016/j.arr.2015.12.008
    The formation of senile plaques followed by the deposition of amyloid-β is the earliest pathological change in Alzheimer's disease. Thus, the detection of senile plaques remains the most important early diagnostic indicator of Alzheimer's disease. Amyloid imaging is a noninvasive technique for visualizing senile plaques in the brains of Alzheimer's patients using positron emission tomography (PET) or magnetic resonance imaging (MRI). Because fluorine-19 ((19)F) displays an intense nuclear magnetic resonance signal and is almost non-existent in the body, targets are detected with a higher signal-to-noise ratio using appropriate fluorinated contrast agents. The recent introduction of high-field MRI allows us to detect amyloid depositions in the brain of living mouse using (19)F-MRI. So far, at least three probes have been reported to detect amyloid deposition in the brain of transgenic mouse models of Alzheimer's disease; (E,E)-1-fluoro-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (FSB), 1,7-bis(4'-hydroxy-3'-trifluoromethoxyphenyl)-4-methoxycarbonylethyl-1,6-heptadiene3,5-dione (FMeC1, Shiga-Y5) and 6-(3',6',9',15',18',21'-heptaoxa-23',23',23'-trifluorotricosanyloxy)-2-(4'-dimethylaminostyryl)benzoxazole (XP7, Shiga-X22). This review presents the recent advances in amyloid imaging using (19)F-MRI, including our own studies.
    Matched MeSH terms: Positron-Emission Tomography/methods*
  14. Ahmad Saad FF, Zakaria MH, Appanna B
    J Int Med Res, 2018 Aug;46(8):3138-3148.
    PMID: 29781364 DOI: 10.1177/0300060518773019
    Objectives 18F-choline is a useful tracer for detecting tumours with high lipogenesis. Knowledge of its biodistribution pattern is essential to recognise physiological variants. The aim of this study was to describe the physiologic distribution of 18F-choline and pitfalls in patients with breast cancer. Methods Twenty-one consecutive patients with breast cancer (10 premenopausal and 11 postmenopausal women; mean age, 52.82 ± 10.71 years) underwent 18F-choline positron emission tomography (PET)/computed tomography (CT) for staging. Whole-body PET/CT was acquired after 40 minutes of 18F-choline uptake. Acquired PET images were measured semiquantitatively. Results All patients showed pitfalls unrelated to breast cancer. These findings were predominantly caused by physiological glandular uptake in the liver, spleen, pancreas, bowels, axial skeleton (85%-100%), inflammation and benign changes (4.76%), appendicular skeleton (4.76%-19.049%), and site contamination (61.9%). In <1%, a concomitant metastatic neoplasm was found. The breast showed higher physiological uptake in premenopausal compared with postmenopausal woman (18F-choline maximum standardised uptake values [g/dL] of the right breast = 2.04 ± 0.404 vs 1.59 ± 0.97 and left breast = 2.00 ± 0.56 vs 1.93 ± 1.28, respectively). Conclusion 18F-choline uptake was higher in premenopausal women. Physiological 18F-choline uptake was observed in many sites, representing possible pathologies.
    Matched MeSH terms: Positron Emission Tomography Computed Tomography*
  15. Mohd Fahmi Shukur Ramli, Fadzilah Hamzah, Muhamad Zabidi Ahmad
    MyJurnal
    Positron Emission Tomography-Computed Tomography (PET-CT) was introduced over four decades ago as an imaging tool to evaluate functional and anatomical aspects of disease such as malignancy. Besides pathological uptake, PET-CT also shows physiological uptake, especially in the gastrointestinal system, thus impacting diagnostic accuracy in these cases. There are many conditions that can attribute to increasing physiological uptake in PET-CT including microbial activity and drugs. Therefore, certain anti-spasmodic agents have been introduced to help reduce physiological uptake during scanning such as Hyoscine-n-butylbromide (Buscopan). This study aims to establish its effectiveness in reducing physiological bowel uptake on 18F-FDG PET-CT scan. Methods: 133 subjects were recruited in random for this study and divided into hyoscine (68 subjects) and control groups (65 subjects), respectively. Subjects in control group not given any anti-spasmodic medications and both groups received intravenous 18F-FDG according to body weight. PET-CT scan and images were interpreted by experienced nuclear medicine physician who scored the images according to the degree of bowel uptake and difficulty of image interpretation. Results: There were no statistical difference in bowel uptake based on SUV mean of the bowel and bowel-to-liver ratio between hyoscine and control groups. Conclusion: There was no significant effect of Hyoscine-n-butylbromide in reducing physiological bowel uptake in PET-CT scan.
    Matched MeSH terms: Positron-Emission Tomography; Positron Emission Tomography Computed Tomography
  16. Abdul Aziz AF, Mohamed AR, Murugesu S, Siti Zarina AH, Lee BN
    Med J Malaysia, 2021 07;76(4):502-509.
    PMID: 34305111
    BACKGROUND: Scalp video electroencephalography monitoring (VEM) and brain MRI sometime fail to identify the epileptogenic focus (EF) in patients with drug resistant epilepsy (DRE). 18F-FDG PET/CT has been shown to improve the detection of EF in patients but is not widely used in Malaysia. Thus, the objective of this study was to identify whether 18F-FDG PET/CT conferred an added benefit in the pre-surgical evaluation of DRE.

    METHODS: Retrospective review of 119 consecutive paediatric patients referred for 18F-FDG-PET/CT at the Department of Nuclear Medicine of the National Cancer Institute, Putrajaya. All had DRE and underwent evaluation at the Paediatric Institute, Hospital Kuala Lumpur. Visually detected areas of 18F-FDG-PET/CT hypometabolism were correlated with clinical, MRI and VEM findings.

    RESULTS: Hypometabolism was detected in 102/119 (86%) 18FFDG- PET/CT scans. The pattern of hypometabolism in 73 patients with normal MRI was focal unilobar in 16/73 (22%), multilobar unilateral in 8/73 (11%), bilateral in 27/73 (37%) and global in 5/73 (7%) of patients; whilst 17/73 (23%) showed normal metabolism. In 46 patients with lesions on MRI, 18F-FDG-PET/CT showed concordant localisation and lateralization of the EF in 30/46 (65%) patients, and bilateral or widespread hypometabolism in the rest. Addition of 18FFDG PET/CT impacted decision making in 66/119 (55%) of patients; 24/73 with non-lesional and 30/46 patients with lesional epilepsies were recommended for surgery or further surgical work up, whilst surgery was not recommended in 11/46 patients with lesional epilepsy due to bilateral or widespread hypometabolism. 25 patients subsequently underwent epilepsy surgery, with 16/25 becoming seizure free following surgery.

    CONCLUSION: 18F-FDG-PET/CT has an added benefit for the localization and lateralization of EF, particularly in patients with normal or inconclusive MRI.

    Matched MeSH terms: Positron Emission Tomography Computed Tomography*
  17. Hassan H, Othman MF, Abdul Razak HR, Zakaria ZA, Ahmad Saad FF, Osman MA, et al.
    Molecules, 2022 Nov 17;27(22).
    PMID: 36432069 DOI: 10.3390/molecules27227969
    [18F]sodium fluoride ([18F]NaF) is recognised to be superior to [99mTc]-methyl diphosphate ([99mTc]Tc-MDP) and 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) in bone imaging. However, there is concern that [18F]NaF uptake is not cancer-specific, leading to a higher number of false-positive interpretations. Therefore, in this work, [18F]AlF-NOTA-pamidronic acid was prepared, optimised, and tested for its in vitro uptake. NOTA-pamidronic acid was prepared by an N-Hydroxysuccinimide (NHS) ester strategy and validated by liquid chromatography-mass spectrometry analysis (LC-MS/MS). Radiolabeling of [18F]AlF-NOTA-pamidronic acid was optimised, and it was ensured that all quality control analysis requirements for the radiopharmaceuticals were met prior to the in vitro cell uptake studies. NOTA-pamidronic acid was successfully prepared and radiolabeled with 18F. The radiolabel was prepared in a 1:1 molar ratio of aluminium chloride (AlCl3) to NOTA-pamidronic acid and heated at 100 °C for 15 min in the presence of 50% ethanol (v/v), which proved to be optimal. The preliminary in vitro results of the binding of the hydroxyapatite showed that [18F]AlF-NOTA-pamidronic acid was as sensitive as [18F]sodium fluoride ([18F]NaF). Normal human osteoblast cell lines (hFOB 1.19) and human osteosarcoma cell lines (Saos-2) were used for the in vitro cellular uptake studies. It was found that [18F]NaF was higher in both cell lines, but [18F]AlF-NOTA-pamidronic acid showed promising cellular uptake in Saos-2. The preliminary results suggest that further preclinical studies of [18F]AlF-NOTA-pamidronic acid are needed before it is transferred to clinical research.
    Matched MeSH terms: Positron-Emission Tomography/methods
  18. Subha ST, Bakri MA, Salleh H, Doi M, Nordin AJ
    Iran J Otorhinolaryngol, 2018 Jan;30(96):49-54.
    PMID: 29387664
    Introduction: Papillary thyroid carcinoma (PTC) constitutes 75-85% of all thyroid cancers. PTC usually presents as a subtle, commonly slow-growing, painless thyroid mass or a solitary nodule in the neck. This presentation of a cystic neck lump, without the presence of a thyroid nodule, may imitate the course of a benign disease, thus delaying diagnosis and proper treatment.

    Case Report: Three cases that had been initially presented as a cystic neck lesion in which a benign etiology was considered primarily were compiled in this study. PTC was only diagnosed after surgical excision of these cystic neck lesions in the first two cases, and after performing fine needle aspiration cytology (FNAC) and an 18fluorine-fluorodeoxyglucose positron emission tomography computed tomography (18F-FDG-PET CT) scan in the latter case.

    Conclusion: PTC can sometimes present as a cystic neck mass; a presentation which is usually related to a benign lesion. This case series emphasizes that patients who appear to have a solitary cystic neck mass must be treated with a high index of clinical suspicion. Although not a first-line imaging modality, 18F-FDG-PET can be extremely useful in assessing patients with a cystic neck lesion, where diagnosis is still uncertain after standard investigations such as ultrasonography and FNAC have been performed.

    Matched MeSH terms: Positron-Emission Tomography; Positron Emission Tomography Computed Tomography
  19. Sethu Thakachy Subha, Fathinul Fikri Ahmad Saad, Abdul Jalil Nordin, Saraiza Abu Bakar
    MyJurnal
    This study sought to prospectively evaluate the influence of contrasted fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDGPET/CT) in the staging of and impact on the management plan for treatment in patients with nasopharyngeal carcinoma (NPC). A total of 14 histologically proven NPC patients (mean age: 44.64±4.01years) were included in the study. These patients underwent contrasted Computed Tomography (CT) as well as 18F-FDGPET/CT imaging. Staging was based on the 7th edition of the American Joint Committee on Cancer Tumor Node Metastases (AJCCTNM) recommendations.The oncologist was asked to prospectively assign a treatment plan for all patients being evaluated by CT and 18F-FDGPET/CT. The treatment plans were compared with the incremental information supplied by the FDG-PET/CT. The maximum standardised uptake value (SUVmax) and the widest dimension of the primary tumour, cervical lymph nodes size and the distant metastatic lesions were quantified on the co-registered PET/CT images by two experienced nuclear radiologists. The contrasted 18F-FDGPET/CT changed the management intent in nine patients (64.7%). A univariate analysis showed that there were significant correlations between SUVmax and the size of the metastatic
    lymph nodes (R2 =0.0761, p
    Matched MeSH terms: Positron-Emission Tomography; Positron Emission Tomography Computed Tomography
  20. Fallahpoor M, Chakraborty S, Pradhan B, Faust O, Barua PD, Chegeni H, et al.
    Comput Methods Programs Biomed, 2024 Jan;243:107880.
    PMID: 37924769 DOI: 10.1016/j.cmpb.2023.107880
    Positron emission tomography/computed tomography (PET/CT) is increasingly used in oncology, neurology, cardiology, and emerging medical fields. The success stems from the cohesive information that hybrid PET/CT imaging offers, surpassing the capabilities of individual modalities when used in isolation for different malignancies. However, manual image interpretation requires extensive disease-specific knowledge, and it is a time-consuming aspect of physicians' daily routines. Deep learning algorithms, akin to a practitioner during training, extract knowledge from images to facilitate the diagnosis process by detecting symptoms and enhancing images. This acquired knowledge aids in supporting the diagnosis process through symptom detection and image enhancement. The available review papers on PET/CT imaging have a drawback as they either included additional modalities or examined various types of AI applications. However, there has been a lack of comprehensive investigation specifically focused on the highly specific use of AI, and deep learning, on PET/CT images. This review aims to fill that gap by investigating the characteristics of approaches used in papers that employed deep learning for PET/CT imaging. Within the review, we identified 99 studies published between 2017 and 2022 that applied deep learning to PET/CT images. We also identified the best pre-processing algorithms and the most effective deep learning models reported for PET/CT while highlighting the current limitations. Our review underscores the potential of deep learning (DL) in PET/CT imaging, with successful applications in lesion detection, tumor segmentation, and disease classification in both sinogram and image spaces. Common and specific pre-processing techniques are also discussed. DL algorithms excel at extracting meaningful features, and enhancing accuracy and efficiency in diagnosis. However, limitations arise from the scarcity of annotated datasets and challenges in explainability and uncertainty. Recent DL models, such as attention-based models, generative models, multi-modal models, graph convolutional networks, and transformers, are promising for improving PET/CT studies. Additionally, radiomics has garnered attention for tumor classification and predicting patient outcomes. Ongoing research is crucial to explore new applications and improve the accuracy of DL models in this rapidly evolving field.
    Matched MeSH terms: Positron-Emission Tomography; Positron Emission Tomography Computed Tomography
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