This report was commissioned by the IRPA President to provide an assessment of the impact on members of IRPA Associate Societies of the introduction of ICRP recommendations for a reduced dose limit for the lens of the eye. The report summarises current practice and considers possible changes that may be required. Recommendations for further collaboration, clarification and changes to working practices are suggested.

Background: Low 25(OH) vitamin D levels have been associated with several autoimmune diseases and recently with autoimmune thyroiditis (AT). The aim of the study was to investigate the association of AT with low 25(OH) vitamin D levels in the elderly. Methods: One hundred sixty-eight elderly subjects (mean age: 81.6 ± 9.4 years) were enrolled. Serum levels of 25(OH) vitamin D, anti-thyroid peroxidase (TPO-Ab), anti-thyroglobulin (TG-Ab) antibodies, free triiodothyronine (FT3), free thyroxine (FT4) and thyroid stimulating hormone (TSH) were measured. Results: The prevalence of AT was significantly higher in subjects with vitamin D deficiency (25(OH) vitamin D < 20 ng/mL) when compared with subjects with normal 25(OH) vitamin D (25(OH) vitamin D ≥ 20 ng/mL) levels (28% vs. 8%, respectively, p = 0.002). Patients with AT and vitamin D deficiency had a comparable hormonal profile compared to patients with AT and vitamin D sufficiency in terms of TSH (p = 0.39), FT3 (p = 0.30), FT4 (p = 0.31), TG-Ab (0.44) and TPO-Ab (0.35). Interestingly, a significant correlation between 25(OH) vitamin D and TPO-Ab (r = −0.27, p = 0.03) and FT3 (r = 0.35, p = 0.006) has been found in subjects with AT while no correlation was found between 25(OH) vitamin D levels and TG-Ab (r = −0.15, p = 0.25), TSH (r = −0.014, p = 0.09) and FT4 (r = 0.13, p = 0.32). Conclusions: These findings suggest that vitamin D deficiency was significantly associated with AT in the elderly. Therefore, the screening for AT should be suggested in subjects with vitamin D deficiency.

Aims and objectives This study aimed to analyse the key factors that influence the overimaging using X-ray such as selfreferral, defensive medicine and duplicate imaging studies and to emphasize the ethical problem that derives from it. Materials and methods In this study, we focused on the more frequent sources of overdiagnosis such as the total-body CT, proposed in the form of screening in both public and private sector, the choice of the most sensitive test for each pathology such as pulmonary embolism, ultrasound investigations mostly of the thyroid and of the prostate and MR examinations, especially of the musculoskeletal system. Results The direct follow of overdiagnosis and overimaging is the increase in the risk of contrast media infusion, radiant damage, and costs in the worldwide healthcare system. The theme of the costs of overdiagnosis is strongly related to inappropriate or poorly appropriate imaging examination. Conclusions We underline the ethical imperatives of trust and right conduct, because the major ethical problems in radiology emerge in the justification of medical exposures of patients in the practice. A close cooperation and collaboration across all the physicians responsible for patient care in requiring imaging examination is also important, balancing possible ionizing radiation disadvantages and patient benefits in terms of care.

Despite a longstanding recognition that radiological protection is not only a matter of science, but also ethics, ICRP publications have rarely addressed the ethical foundations of the system of radiological protection explicitly. The purpose of this publication is to describe how the Commission has relied on ethical values, either intentionally or indirectly, in developing the system of radiological protection with the objective of presenting a coherent view of how ethics is part of this system. In so doing, it helps to clarify the inherent value judgements made in achieving the aim of the radiological protection system as underlined by the Commission in Publication 103. Although primarily addressed to the radiological protection community, this publication is also intended to address authorities, operators, workers, medical professionals, patients, the public, and its representatives (e.g. NGOs) acting in the interest of the protection of people and the environment. This publication provides the key steps concerning the scientific, ethical, and practical evolutions of the system of radiological protection since the first ICRP publication in 1928. It then describes the four core ethical values underpinning the present system: beneficence/ non-maleficence, prudence, justice, and dignity. It also discusses how these core ethical values relate to the principles of radiological protection, namely justification, optimisation, and limitation. The publication finally addresses key procedural values that are required for the practical implementation of the system, focusing on accountability, transparency, and inclusiveness. The Commission sees this publication as a founding document to be elaborated further in different situations and circumstances.

PET with 18 F-choline ( 18 F-FCH) is used in the diagnosis of prostate cancer and its recurrences. In this work, biodistribution data from a recent study conducted at Skå ne University Hospital Malmö were used for the development of a biokinetic and dosimetric model. Methods: The biodistribution of 18 F-FCH was followed for 10 patients using PET up to 4 h after administration. Activity concentrations in blood and urine samples were also determined. A compartmental model structure was developed, and values of the model parameters were obtained for each single patient and for a reference patient using a population kinetic approach. Radiation doses to the organs were determined using computational (voxel) phantoms for the determination of the S factors. Results: The model structure consists of a central exchange compartment (blood), 2 compartments each for the liver and kidneys, 1 for spleen, 1 for urinary bladder, and 1 generic compartment accounting for the remaining material. The model can successfully describe the individual patients' data. The parameters showing the greatest interindividual variations are the blood volume (the clearance process is rapid, and early blood data are not available for several patients) and the transfer out from liver (the physical half-life of 18 F is too short to follow this long-term process with the necessary accuracy). The organs receiving the highest doses are the kidneys (reference patient, 0.079 mGy/MBq; individual values, 0.033-0.105 mGy/MBq) and the liver (reference patient, 0.062 mGy/MBq; individual values, 0.036-0.082 mGy/MBq). The dose to the urinary bladder wall of the reference patient varies between 0.017 and 0.030 mGy/MBq, depending on the assumptions on bladder voiding. Conclusion: The model gives a satisfactory description of the biodistribution of 18 F-FCH and realistic estimates of the radiation dose received by the patients.