China
Africa
Explore chapters and articles related to this topic
Non-FDG radionuclide imaging and targeted therapies
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Luigi Aloj, Ferdia A Gallagher
The development of new PET probes has provided a rich opportunity for interrogating varying aspects of tumour biology and a range of isotopes have been used to label these probes: each labelling approach has relative strengths and weaknesses. The relatively long half-life of fluorine-18 (18F; 110 min) allows slow metabolic processes to be studied, and these tracers can be generated at a central site and distributed locally for imaging. The use of 18F is often ideal when developing a novel probe, but incorporation of fluorine into a biological molecule can be chemically challenging and the derivative is frequently handled very differently in vivo compared to its unlabelled counterpart. Examples include 18F-labelled sodium fluoride (NaF), 3-deoxy-3-[18F]fluorothymidine (FLT), O-(2-[18F]fluoroethyl)-l-tyrosine (FET), and [18F]-fluoromisonidazole (FMISO); see Table 44.1.
Familial Wilms Tumor and Related Syndromes
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
CT scan of the abdomen is a sensitive technique for confirming the renal origin of the mass, determining bilateral tumors, and identifying cavoatrial thrombus. CT scan of the chest helps identify metastatic lung nodules, which occur in 15% of WT patients. Furthermore, fluorine F 18-fludeoxyglucose (18F-FDG) positron emission tomography (PET)-CT is also useful for detecting bilateral disease.
Other Cyclotron Radionuclides
Published in Frank Helus, Lelio G. Colombetti, Radionuclides Production, 2019
Natural fluorine consists only of 19F, and nonradioactive tracer nuclide does not exist in fluorine. Fluorine-18 (110 m half-life; β+ decay; 0.635 MeV max. β+ energy; no γ-ray; 9.5 × 107Ci/g specific activity in carrier-free state) is the longest-lived radiofluorine, though its life is rather short for many applications in which 18F should first be introduced in an organic compound. The low β+ energy makes this nuclide ideal for the positron-emitter localization measurement.
Utilizing clinical, pathological and radiological information to guide postoperative radiotherapy in prostate cancer
Published in Expert Review of Anticancer Therapy, 2023
Jerusha Padayachee, Simone Chaudhary, Brian Shim, Jonathan so, Remy Lim, Srinivas Raman
Over the last decade, there has been increasing utilization of molecular imaging in guiding cancer therapy through initial staging, assessment of treatment response, and identifying relapse. In the setting of prostate cancer, PET/CT using PSMA tracers radiolabelled with 68-Gallium (68Ga) or 18-Fluorine (18F) has emerged as an important imaging modality. PSMA is a transmembrane glycoprotein that is overexpressed in prostate cancer cells. In normal human prostate, PSMA is localized to the cytoplasm and apical side of the epithelium lining prostatic ducts [76]. With malignant transformation of prostate tissue, PSMA is transferred to the luminal surface of the ducts [76]. To that end, PSMA offers 100–1000 fold increase in expression of prostatic cancer cells compared with normal tissue, making it an ideal molecular imaging target [77]. In addition, PSMA is easily internalized into prostate cancer cells once bound by small radiolabelled molecules such as 68Ga-PSMA-11 and 18F-DCFPyL [78].
Synthetic methodologies and PET imaging applications of fluorine-18 radiotracers: a patent review
Published in Expert Opinion on Therapeutic Patents, 2022
Sridhar Goud Nerella, Ahana Bhattacharya, Pavitra S Thacker, Sanam Tulja
In electrophilic fluorine-18 approach, the 18F-radionuclide is generated by irradiating molecular dioxygen enriched with oxygen-18 ([18O]O2) in a metal target with high energy protons (10 MeV) releases fluorine-18, which gets stuck on metal target walls followed by the addition of a mixture of molecular fluorine and noble-gas (Ne: F = 98:2) with continuous irradiation causes isotopic exchange between fluorine-18 and the molecular fluorine, and finally releases 18F-radionuclide as 18F-F2 fluorine gas in which one atom is radioactive 18F isotope, and another one is stable fluorine atom [12]. Hence, the radiochemical yield is always less than 50%. Since the [18F]F2 fluorine is in gaseous form and can cause radiation exposure and chances of leakage from hot cells. The low molar activity (0.05–0.5 GBq/μmol), and limited automated modules are available due to its drawbacks [13]. The clinically used radiotracers like [18F]FDG, 18F-L-DOPA, and 18F-labeled 5-fluorouracil were synthesized via an electrophilic substitution mechanism (Figure 1) using specific precursors with 18F-F2 isotope gas [14–16].
Aptamer-based technology for radionuclide targeted imaging and therapy: a promising weapon against cancer
Published in Expert Review of Medical Devices, 2020
Luca Filippi, Oreste Bagni, Clara Nervi
The main purpose of nuclear imaging is represented by the detection and the quantification of metabolic and molecular changes due to different pathological conditions in living subjects. This approach entails the administration of radiolabeled probes and the detection of photons produced in the process of radioactive decay and interaction with neighboring tissues. Different modalities of detection can be applied, depending on the type of radionuclide bound to the probe. In case of a gamma-emitting probe, such as the already cited 99mTc, or indium-111 (111In) and iodine-123 (123I), the appropriate technological approach is represented by gamma-camera also through single-photon emission tomography (SPECT) or hybrid SPECT/CT system [19]. On the contrary, positron emission tomography (PET/CT) approach, which is characterized by superior sensitivity, spatial resolution, and quantification capabilities, is applied when molecular probes are labeled with positron emitting radionuclides, such as fluorine-18 (18 F) and gallium-68 (68 Ga).