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Radiolabeled Nanoparticles for Cancer Diagnosis
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
R. G. Aswathy, D. Sakthi Kumar
Nuclear imaging utilizes radioisotopes for the investigation and examination of the physiological and metabolic effects of the body. In nuclear imaging, radiopharmaceuticals are non-invasively administrated to the patients and the radiation emitted is recorded. The data acquired is used for diagnosis specifically for detecting functional abnormalities and early detection of tumors. The most common types of nuclear imaging methods are based on single photon emission computed tomography (SPECT) and positron emission tomography (PET) (Figure 3.1).
Radionuclide-based Diagnosis and Therapy of Prostate Cancer
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Sven-Erik Strand, Mohamed Altai, Joanna Strand, David Ulmert
Many radiopharmaceuticals have been suggested for diagnosis of PCa by methods that complement clinical and PSA diagnostics. A summary of some of those commonly used radiopharmaceuticals is given below. These radiopharmaceuticals can be divided into three main groups – agents targeting the bone matrix, agents for imaging of metabolism and proliferation, and agents targeting receptors and membrane proteins.
Medical and Biological Applications of Low Energy Accelerators
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
Therapeutic radiopharmaceuticals play a major role in today's nuclear medicine with a positive impact on the diagnosis and treatment of diseases. One area of application is radiation synovectomy (RSV). Previously, RSV agents were often simple colloids. More recently, matrixes labeled with short/medium range beta emitters have been developed. However, the lack of generic and peer-reviewed production, quality control as well as clinical application guidelines and recommendations, are a major concern for their application in patients. The publication (IAEA 2021) presents recommendations and suggestions for production, quality control and quality assurance procedures for its member state laboratories in charge of radiopharmaceutical production, with a focus on the latest RSV agents. It also proposes standard operating procedures for RSV application in patients.
Peptide receptor radionuclide therapy in neuroendocrine neoplasms and related tumors: from fundamentals to personalization and the newer experimental approaches
Published in Expert Review of Precision Medicine and Drug Development, 2023
Radiopharmaceuticals are special type of radioisotope tagged biological molecules (termed as ligands), employed for diagnostic or therapeutic purposes, herein used for the purpose of therapy. The word itself can be spliced to ‘Radionuclide’ and ‘pharmaceutical agent’ where the pharmaceutical molecule (termed as ‘ligand’) which acts as a vehicle binds to the specific target (in this case, the SSTR analogs such as octreotate which target the SSTR receptors on NEN cells) and radionuclides are specific radioactive isotopes (e.g. β-emitter like 177Lu or 90Y) which deliver high energy radiation and irradiate tumor tissue to produce therapeutic effects. The concept of bifunctional chelating agent (BFCA) is also important here, these are special molecules like DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) which possess co-ordinating sites that chelate the metallic radionuclides (177Lu,90Y) and a functional group enabling the attachment to the carrier pharmaceutical agents (SSTR analogs). This assembly is illustrated in Figure 1 which is the typical structure of radiopharmaceuticals used in PRRT. After binding to SSTR receptors which is a type of G protein-coupled receptor, it gets internalized and irradiates intracellular structures including DNA molecules by its attached radioisotope to produce lethal and specific damage. Bystander and abscopal effects related to cellular damage on the adjacent tumor cells have also been postulated.
Radiomics and theranostics with molecular and metabolic probes in prostate cancer: toward a personalized approach
Published in Expert Review of Molecular Diagnostics, 2023
Luca Filippi, Luca Urso, Francesco Bianconi, Barbara Palumbo, Maria Cristina Marzola, Laura Evangelista, Orazio Schillaci
Molecular imaging (MI) is based on the administration of radiopharmaceuticals suitable to assess and measure changes occurring during physiopathological processes by employing radiolabeled molecules, namely, radiopharmaceuticals [12]. Once a radiopharmaceutical has been administered and incorporated into a specific site of the body, an appropriate technology, depending on the physical properties of the emitting radionuclide, is employed for detection. In the case of gamma-emitters, conventional scintigraphy is used, while in the case of positron-emitters, the detection is carried out through hybrid positron emission tomography/computed tomography (PET/CT). The main limitation of MI performed by gamma-emitting tracers is represented by the relatively low spatial resolution of conventional scintigraphy performed either with planar images or by single photon emission computed tomography (SPECT), partially overcome by the introduction of hybrid SPECT/CT devices [13]. In this regard, it has to be underlined that PET/CT shows a superior diagnostic performance in comparison with SPECT/CT, also allowing accurate calculation of relevant quantitative parameters. Furthermore, in last years, the implementation of silicon-photomultipliers (SiPM)-based detectors has further improved PET/CT’s sensitivity and spatial resolution giving rise to the so-called ‘digital PET/CT’ [14,15] and, even more recently, a new type of PET/CT scanners, characterized by long axial field-of-view and exquisite sensitivity, has been introduced in clinical practice with overwhelming results [16].
Prostate-specific membrane antigen-directed imaging and radioguided surgery with single-photon emission computed tomography: state of the art and future outlook
Published in Expert Review of Medical Devices, 2022
Luca Filippi, Barbara Palumbo, Viviana Frantellizzi, Susanna Nuvoli, Giuseppe De Vincentis, Angela Spanu, Orazio Schillaci
Nuclear medicine is based on the administration of radiopharmaceuticals aimed to investigate physio-pathological phenomena at a cellular and molecular level. After radiotracers’ injection and localization in the site of interest, imaging is obtained through the detection of the photons produced during the process of radioactive decay and the interaction with the neighboring tissues. When single-photon emitting tracers are employed, detection is carried out by gamma-camera through planar images and/or SPECT. The main advantage of planar images is their capability to register in real-time radiotracers’ biodistribution through dynamic acquisition, while the main limitation is the low sensitivity since only photons emitted parallel to the collimators (or within a certain angular region, if collimators different from parallel are employed) are allowed to reach the detectors [19]. SPECT is obtained by rotating detectors around the patient, so that it is possible to acquire the activity distribution under multiple angles, namely ‘projections,’ that are then reconstructed into a 3D volume through several software packages. Hybrid SPECT/CT, combining a variable-angle gamma-camera with an X-ray tube, allows an accurate co-registration of functional and anatomical images and also provides attenuation map of the patient [20].