Current Radiopharmaceuticals - Volume 18, Issue 1, 2025

The reproductive organ, housing spermatogonial stem cells (SSCs), undergoes ongoing division impacted by the irradiation dosage and exposure duration. Within the male reproductive organ, germ stem cells (spermatogonia) and somatic cells (Sertoli and Leydig cells) are present. Lower doses of ionizing (>4-6 Gy) and non-ionizing radiation (radiofrequency and microwave range 900 MHz - 2.45 GHz) may cause sperm-related issues, while higher doses (15 Gy) may affect Leydig cells and testosterone production. Response to radiation varies with age and pubescence. Spermatogonial stem cells, crucial for regenerating the spermatogenic lineage, express molecular markers like Estrogen receptor, FSH (Follicular Stimulating Hormone) receptor, TLR-4 (Toll-like Receptor-4), TLR-5 (Toll-like Receptor-5), FGF2 (Fibroblast Growth Factor-2), KIT (Receptor Tyrosine Kinase), AT-1 (Angiotensin II Type-1 Receptor), LXRs-γ (Liver X Receptor-γ), TNF-β (Tumor Necrosis Factor-β), and PCNA (Proliferating Cell Nuclear Antigen), influencing stem cell activity in testes.

This study aimed to review the various available radioprotective agents and their efficacy in targeting the male reproductive system from the available literature.

Various radioprotective herbal/synthetic/microbial/metallic extracts/formulations/
drugs [Septilin, Silymarin, Organic Turmeric, Oestrogen, Melatonin, Febuxostat, SQGD (Semiquinone glucoside derivative), Rapamycin, Entolimod, Zinc, Selenium, etc.] have been investigated up to exposure, but owing to effectiveness issues, they are unable to fulfil the aim to the fullest of restoring male fertility and normal testosterone levels during such eventuality.

Further study is needed to optimize these tactics and fill knowledge gaps. Also, the effective components of herbal, synthetic drugs, etc., should be isolated and tested up to clinical levels, paving the way for successful radioprotection and radiomitigation strategies in the male reproductive system.

In this study, [⁶⁴Cu]Cu-NODAGA-RGD-BBN was prepared and its preclinical assessments were evaluated for PET imaging of GRPR overexpressing tumors.

NODAGA-RGD-BBN heterodimer peptide was successfully labeled with cyclotron-produced copper-64 at optimized conditions. The radiochemical purity of the radiotracer was checked by HPLC and RTLC methods. The stability of the radiolabeled compound was assessed in PBS (4°C) and in human blood serum (37°C). Binding affinity and internalization of [⁶⁴Cu]Cu-NODAGA-RGD-BBN were studied on PC3, LNCaP, and CHO cell lines. The biodistribution of the radiotracer was evaluated in normal and tumor-bearing mice.

[⁶⁴Cu]Cu-NODAGA-RGD-BBN was prepared with radiochemical purity >99 ± 0.7% (HPLC/ITLC) and specific activity of 18.5 ± 2.2 TBq/mmol. The radiotracer showed high stability in PBS (95 ± 1.05%) and in human blood serum (96 ± 1.24%) and, high affinity to the GRP expressing tumor cells. [⁶⁴Cu]Cu-NODAGA-RGD-BBN showed hydrophilic (log p = -1.14) and agonistic nature. The biodistribution and imaging studies demonstrated high uptake at the tumor site at all intervals post-injection and 3-4 h post-injection can be considered an appropriate time of imaging.

The results indicated that [⁶⁴Cu]Cu-NODAGA-RGD-BBN radiolabeled heterodimer peptide can be considered as a high-potential agent for PET imaging of GRPR-overexpressing tumors.

Radiopharmaceuticals are radioactive compounds used for diagnostic or therapeutic purposes which are most often administered intravenously. Adverse events that may induce both adverse reactions and drug-to-drug interactions with changes in expected biodistribution, potentially affecting patient safety and diagnostic accuracy. Adverse reactions are relatively rare due to the small doses and under-reporting is the norm. The aim of this study is to increase awareness of the need to report in order to create protocols for the management of such adverse events among professionals in a Nuclear Medicine Department.

A reporting system was established a decade ago through an electronic form to enhance adverse event registration. The radiopharmacist collects data for further communication with National Health authorities and develops an annual report with recommendations on the management of these adverse events.

A total of 128 reports were collected, including 65 cases of extravasations, 18 adverse reactions, and 45 drug interactions. Over the years, reporting has been increasing, adverse reactions occurred at a higher incidence than reported in the literature, and each anomalous biodistribution was analysed for possible drug interaction. The annual reports have been used to develop a local guideline for the management of adverse reactions and recommendations for discontinuation of treatment to avoid interactions with radiopharmaceuticals.

The recognition of adverse events associated with radiopharmaceuticals is increasing, underlining the need for vigilant reporting and improved management strategies. An efficient reporting system promotes awareness of possible interactions between radiopharmaceuticals and other medicines and their potential adverse reactions to enhance patient safety.

Evidence of inappropriate overuse and underuse of medical procedures has been documented in modern healthcare systems around the world. Excessive use of health services can contribute to a rapid increase in healthcare costs and harm the patient physically and psychologically; conversely, underuse can lead to the inability to provide effective treatments when clinically indicated.

The study's aim is twofold: a) to measure the appropriateness of PET prescription in a cohort of patients, offering empirical evidence of overuse of health care services; b) to evaluate how the overuse of PET could affect public health expenditure and, consequently, the system's financial sustainability.

In this observational study, we have analyzed prospectively and retrospectively health patient records who underwent 18F-FDG PET/TC scan at the Nuclear Medicine Department of the University Hospital Mater Domini in Catanzaro (Italy) from 29/09/2022 to 10/02/2023. Patients’ diagnostic questions have been defined as appropriate, not completely appropriate and completely inappropriate according to the 18F-FDG PET/CT recommendations defined by the “Conditions of Supply and Indications of Prescriptive Appropriateness of Italian NHS (National Health Systems)” published in the Official Gazette no. 15 of 20 January 2016 (Decree 9 December 2015) and by the AIMN (Italian Association of Nuclear Medicine) guidelines.

We gathered data from 500 oncological patients (242 males and 258 females). The results show that 423/500 of patients' prescriptions were appropriate, while 77/500 of patients' prescriptions were completely inappropriate (63/77) or not completely appropriate (14/77).

Analysis showed a not complete adherence to national guidelines and no shared decision-making approach.

Traditional cell-based radiobiological methods are inadequate for assessing the toxicity of ionizing radiation exposure in relation to the microstructure of the extracellular matrix. Organotypic tissue slices preserve the spatial organization observed in vivo, making the tissue easily accessible for visualization and staining. This study aims to explore the use of fluorescence microscopy of physiologically relevant 3D tissue cultures to assess the effects of ionizing radiation.

Organotypic tissue slices were obtained by vibratome, and their mechanical properties were studied. Slices were exposed by two ionizing radiation sources; electron beams (80 Gy and 4 Gy), and soft gamma irradiation (80 Gy and 4 Gy). Two tissue culture protocols were used: the standard (37°C), and hypothermic (30°C) conditions. A qualitative analysis of cell viability in organotypic tissue slices was performed using fluorescent dyes and standard laser confocal microscopy.

Biological dosimetry is represented by differentially stained 200-μm thick organotypic tissue sections related to living and dead cells and cell metabolic activity.

Our results underscore the ability of fluorescence laser scanning confocal microscopy to rapidly assess the radiobiological effects of ionizing radiation in vitro on 3D organotypic tissue slices.

Alveolar rhabdomyosarcoma (ARMS) predominantly affects adolescents aged 10-15 years and is distinguished by its high aggressiveness and adverse prognosis compared with other sarcomas. It exhibits a pronounced tendency for lymphatic and hematogenous metastases at early stages. ARMS commonly manifests in the limbs and genitourinary system, with occurrences in the head and neck region being relatively uncommon. The role of CT, MRI, and 18F-FDG positron emission tomography combined with computed tomography (PET/CT) in the diagnostic process of ARMS is yet to be fully established.

We report the case of a 49-year-old woman who presented with hematological nasal discharge for one month. CT imaging revealed a soft tissue mass in the left nasal cavity. MRI demonstrated a marginally hypo- to isointense signal on T1-weighted images, a hyperintense signal on T2-weighted images, and heterogeneous enhancement post-contrast. ¹⁸F-FDG PET/CT identified a hypermetabolic lesion located within the left nasal cavity. Surgical intervention entailed the excision of the left intranasal mass and the skull base lesion. Postoperative pathological analysis indicated ARMS.

Sinus ARMS is notably malignant and associated with a dismal prognosis. Accurate diagnosis depends on histopathological and immunohistochemical evaluation, complemented by genetic analysis for specific chromosomal translocations and fusion genes. Imaging techniques, including CT, MRI, and PET/CT, are crucial for assessing lesion extent and metastasis, supporting disease diagnosis, informing treatment choices, facilitating surgical planning, and monitoring response to therapy.