[⁶⁸Ga]Ga-PSMA-11 is a prostate-specific membrane antigen (PSMA)-targeting radiopharmaceutical based on lysine-urea-glutamic acid derivatives. This study aimed to identify the cause of the irregular decrease in the radiosynthesis yield of [⁶⁸Ga]Ga-PSMA-11 and to suggest a solution. An irregular decrease in production yield occurred during the synthesis of [⁶⁸Ga]Ga-PSMA-11 using a cassette-based automatic synthesizer. Although the reagents used in synthesizing [⁶⁸Ga]Ga-PSMA-11 were replaced with new products, the irregular decrease in radiosynthesis yield continued. In addition, cassettes, equipment, and operating programs used in the cassette-based automatic synthesizer operated normally. On the other hand, when eluting with 0.6 N hydrochloric acid(HCl), leakage was found at the outlet line connection site of the ⁶⁸Ge/⁶⁸Ga generator. The ⁶⁸Ge/⁶⁸Ga generator was eluted with 0.6 N HCl two to four hours before synthesis to remove impurities and improve the synthetic yield reduction. No further irregular yield reduction occurred after using this method. In the event of an irregular decrease in the radiolabeling yield, the pretreatment method developed in this study would help produce [⁶⁸Ga]Ga-PSMA-11 injections with a stable labeling yield.

Boron neutron capture therapy (BNCT) represents a cutting-edge approach in cancer treatment, offering a promising avenue to enhance cure rates for patients resistant to conventional therapies. A critical factor for successful BNCT is the development of boron drugs with exceptional tumor selectivity. In this study, we synthesized a novel benzothiazole derivative, potassium (4-(benzo[d]thiazol-2-yl)-2,6-difluorophenyl) trifluoroborate (B13), incorporating boron and fluorine. Following its synthesis, we radiolabeled the drug with ¹⁸F via a ¹⁹F/¹⁸F isotope exchange reaction, producing ¹⁸F-B13 with good radiochemical purity and yield. Notably, the radiotracer demonstrated significant uptake in U87MG tumors, as evidenced by PET imaging. Biodistribution analysis revealed a substantial accumulation of boron (4 ppm) in U87MG tumors 1h post-intravenous injection. Moreover, it showcased significant tumor/muscle ratios (2.04) 2 h post-injection. While the tumor selectivity of B13 did not meet the stringent standards for BNCT, its potential as a BNCT tracer remains promising. Notably, the tumor/muscle ratio remained elevated up to two hours post-injection, suggesting future avenues for optimization and clinical translation.

Purpose: The objective of this study was to evaluate the estimated radiochemical yield (RCY) and quality of routine [¹⁸F]FDG production over two years (2022 and 2023) at Mongolia's first cyclotron facility, utilizing the MINItrace Qilin cyclotron (GE Healthcare, 9.6 MeV) and FASTLab 2 radiosynthesizer (GE Healthcare). Methods: [¹⁸F]Fluoride was generated using a MINItrace Qilin cyclotron, producing up to 2 Ci of radioactivity per run, 2-3 runs per week. The [¹⁸F]FDG production was carried out using the FASTLab 2 radiosynthesizer utilizing FDG Duo and Single Citrate cassettes through nucleophilic radiofluorination of mannose triflate followed by basic hydrolysis. Quality Controls, including radiochemical purity, radionuclidic purity and identity, chemical purity, residual solvents, assay for radioactivity, bacterial endotoxins, and sterility, were performed in accordance with United States Pharmacopeia (USP) standards using bSCAN TLC Scanner, Captus-3000 MCA, Scion-456 GC, and Endosafe nexgen-PTS. Facility design and operation were managed in accordance with International Atomic Energy Agency guidelines to ensure GMP compliance. Results: All quality control tests met the USP requirements, ensuring safe injections for patients. The RCY were within acceptable ranges. The RCY of the FASTLab 2 Duo cassette was consistently higher than that of the Single Citrate cassette throughout the study period. The RCY for both cassettes were gradually decreased over time, with no significant correlation between cyclotron maintenance and subsequent RCY. Conclusions: Further investigation is needed to identify factors contributing to the decreasing radiochemical yield.

Prostate cancer (PCa) is the second most frequent cancer. Prostate specific membrane antigen (PSMA) is an effective target for the detection, staging and monitor the response of therapy in the management of PCa. In this study, we aimed to develop a ¹⁸F-labeled PSMA-PET tracer ([¹⁸F]AlF-ND-GUL) and test its feasibility for targeting PCa. A variety of labeling conditions was tested for optimization to achieve maximum radiolabeling efficiency. To test the imaging capacity of [¹⁸F]AlF-ND-GUL, in vivo PET/MR images were performed in 22Rv1 tumor bearing BALB/c nude mice after injection of radiotracer. Optimized labeling condition was to dissolve 300 nmol of precursor (ND-GUL) in buffer (pH 4, 0.1 M, NaOAc-HOAc) and react with [¹⁸F]AlF at 110℃ for 30 min. The [¹⁸F]AlF-ND-GUL maintained stability of >85% over 4 h. In-vivo molecular PET/MR imaging study results clearly showed high tumor uptake of [¹⁸F]AlF-ND-GUL over time. In conclusion, we optimized [¹⁸F]AlF-ND-GUL labeling conditions for PCa diagnosis and confirmed PSMA specific binding in vivo.

Targeted alpha therapy (TAT) harnesses the potent cytotoxicity of alpha particles emitted by radioisotopes to selectively eradicate cancer cells while minimizing damage to surrounding healthy tissues. Developing radiopharmaceutical for TAT, alpha particle imaging devices are used to identify distribution and behavior of the radiopharmaceutical in body, to evaluate efficacy and safety of the radiopharmaceutical. This paper explores the challenges and advancements in alpha particle imaging devices for TAT. Researchers are turning to innovative alpha particle imaging devices capable of directly detecting alpha particles to achieve higher spatial resolution and accuracy in mapping radioisotope distribution within organs. This review surveys the landscape of alpha particle imaging devices developed worldwide, including scintillator based-, semiconductor based-, and gas detector based systems. Their underlying principles, unique features, and strategies for enhancing performance are examined. By shedding light on the state-of-the-art technologies supporting advancements in TAT research, this review aims to introduce the ongoing efforts to refine the vision on biodistribution of radiopharmaceuticals for TAT.

Iodine contributes a major chunk of radioactive waste due to its broad spectrum of unstable isotopes. The environmental dissemination of these isotopes stems from nuclear reactors, the nuclear medicine industry, and nuclear calamities. Owing to the harmful effects of radioiodine on human health, many materials have been tested to remove iodine from wastewater streams. Among these materials, nanoparticles have shown significant ability because of their nanosized effects, high specific surface area, and ability to carry multiple functional groups. This paper, therefore, aims to review the nanoparticles that have shown sufficient adsorption for iodine in aqueous media. The manuscript seeks to elucidate the rationale for selecting specific nanomaterials and expound upon the underlying mechanisms governing the adsorption rate. It also discusses the necessary conditions for optimizing adsorption rates and the inherent limitations of these nanomaterials.

Boron neutron capture therapy (BNCT) stands at the forefront of cancer treatment, offering a pioneering approach to enhance the rate of recovery for patients who show noncompliance to conventional therapies. The ¹⁸F labeling of BNCT tracers signifies a groundbreaking leap in molecular imaging. Hence, the aim of this brief review is to outline the radiofluorination strategies utilized for BNCT tracers. Radiofluorination of L-BPA, a ligand of L-type amino acids, can be carried out via electrophilic as well as nucleophilic substitution reactions. It's solubility can be elevated by complexing it with fructose to form BPA-fructose complex, followed by radiolabeling with ¹⁸F. In addition to electrophilic and nucleophilic radiofluorination, we have briefly presented the radiofluoro exchange method, which is applicable for amino acids having trifluoroborate groups, i.e., FBY (fluoroboronotyrosine), featuring both imaging and therapeutic functionalities. Furthermore, this review offers an inclusive array of radiofluorination strategies employed for other BNCT tracers, including o-carborane and fenbufen boronopinacol.

Recent advances in disease understanding have led to the discovery of new molecular targets and biomarkers. Therapeutic antibodies targeting specific molecules have been successful in the development of antibody-drug conjugates (ADCs) due to their proven clinical effectiveness and manageable toxicity. Antibody-radionuclide conjugates (ARCs), which use radionuclides instead of drugs, also show promise for their potential therapeutic effects in radioimmunotherapy. Identifying these biomarkers before treatment is increasingly important, leading to personalized medicine. Immuno-positron emission tomography (PET) using radiolabeled monoclonal antibodies is promising for non-invasively assessing target expression and distribution. It can provide valuable information for risk assessment, diagnosis, treatment selection, and evaluation of treatment response. This review discusses recent developments in ADC and ARC and aims to explore opportunities for the simultaneous progress of these drugs.

Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by the SARS-CoV-2 coronavirus, which had been identified in Wuhan, China, in December 2019. COVID-19 is a serious threat to human health and spread worldwide. World Health Organization (WHO) has declared the COVID-19 pandemic. It is important that vaccines and therapeutics are developed to control COVID-19. Among these, vaccines using COVID-19 mRNA platforms have various advantages, including a short development cycle, an easy industrialization, a simple production process, flexibility for new variants, and the capacity to induce better immune responses. This review summarizes the structure and characteristics of coronaviruses and introduces the use of non-clinical pharmacokinetic evaluation with C-14 in mRNA vaccine development. The in vitro stability of C-14 labeled mRNA carrier ([¹⁴C]mRNA carrier) was evaluated and found to be stable for up to 144 hours in rat serum. The [¹⁴C]mRNA carrier was distributed mostly to the administration site in rats, but slowly distributed to other organs after 48 hours. Most of the [¹⁴C]mRNA carrier remained in the administered muscle and was slowly excreted from the body through urine after 72 hours. There was no statistical difference in the distribution and excretion after intramuscular administration of the [¹⁴C]mRNA carrier to male and female rats. Through this paper, it is expected to contribute to the development of drug carriers through various studies using C-14.

Peptide-based radiopharmaceuticals have brought significant advancements in the diagnosis and treatment of various cancers, serving as a powerful tool in nuclear medicine. These radiopharmaceuticals utilize the high specificity of peptides for certain cell receptors, such as the prostate-specific membrane antigen in prostate cancer and somatostatin receptors in neuroendocrine tumors. This review paper aims to describe the clinical benefits of peptide-based radiopharmaceuticals, emphasizing their high target affinity, improved imaging quality, and therapeutic efficacy. By integrating ongoing research and clinical trial data, the innovative impact of peptide-based radiopharmaceuticals in nuclear medicine is highlighted.

Relative biological effectiveness (RBE) plays an important role in relating physical dose to cell-killing biological dose. The calculation of the RBE is an important basic task in realization of radionuclide therapy using ⁶⁴Cu. In this study, the method of calculating the RBE of emitted particles from ⁶⁴Cu is presented using Monte Carlo simulation. U-87 MG cell model is designed to perform Monte Carlo simulation. The Geant4 simulation tool kit was used to simulate the secondary particles for transport into media. The specific energy in the cell nucleus and the domain was estimated. The Microdosimetric Kinetic model (MK model) is used to estimate RBE. The method presented in this study may be helpful to estimate biological dose in treatment with ⁶⁴Cu.