EURADOS intercomparison IC2020ph on whole body dosemeters for photons.

The European Dosimetry Group has been organising international intercomparisons (ICs) for personal dosemeters on a regular basis. The IC announced in 2020 was postponed to the end of 2020 and the beginning of 2021 due to coronavirus (COVID-19) restrictions. The irradiation plan consisted of nine irradiation setups with five different photon radiation qualities (S-Cs, S-Co, N-150, W-60, W-80) and two different angles of irradiation incidence (0o and 60o). A total of 112 monitoring services from 50 countries with 132 dosimetry systems participated. The present work describes and analyses the individual results for the personal dose equivalent quantities Hp(10) and, if submitted, Hp(0.07) for all participating systems. It also presents the organisational details and the difficulties arising from the COVID-19 crisis during the IC. The statistical results showed a satisfactory performance with the medians of all Hp(10) and Hp(0.07) response values very close to unity. However, there are few individual monitoring services with significant large variations.

Scattered Radiation Distribution Utilizing Three Different Cone-Beam Computed Tomography Devices for Maxillofacial Diagnostics: A Research Study.

This study aimed to estimate scattered radiation and its spatial distribution around three cone-beam computed tomography (CBCT) devices, in order to determine potential positions for an operator to stand if they needed to be inside the CBCT room. The following devices were tested: Morita Accuitomo (CBCT1), Newtom Giano HR (CBCT2), Newtom VGi (CBCT3). Scattered radiation measurements were performed using different kVp, mA, and Field of View (FOV) options. An anthropomorphic phantom (NATHANIA) was placed inside the X-ray gantry to simulate clinical conditions. Scattered measurements were taken with the Inovision model 451P Victoreen ionization chamber once placed at fixed distances from each irradiation isocenter, away from the primary beam. A statistically significant (p < 0.001) difference was found in the mean value of the scattered radiation estimations between the CBCT devices. Scattered radiation was reduced with a different rate for each CBCT device as distance was increased. For CBCT1 the reduction was 0.047 µGy, for CBCT2 it was 0.036 µGy, and for CBCT3 it was 0.079 µGy, for every one meter from the X-ray gantry. Therefore, at certain distances from the central X-ray, the scattered radiation was below the critical level of 1 mGy, which is defined by the radiation protection guidelines as the exposure radiation limit of the general population. Consequently, an operator could stay inside the room accompanying the patient being scanned, if necessary.

Prevention of and response to inadvertent exposure of embryo/fetus to ionizing radiation, due to medical exposure of the mother. The Greek regulatory authority initiatives.

Embryo/fetus (E/F) irradiation as a result of medical exposure of the mother should be avoided, unless there are strong clinical indications. Medical practitioners are assigned the primary task and obligation of ensuring overall patient protection and safety in the prescription of and during the delivery of medical exposure. In cases of unintended exposure of embryo/fetus (E/F), the risk analysis and communication is conducted by or under the supervision of medical physicists at local level. National competent authorities can contribute to the prevention, risk analysis and communication of inadvertent E/F exposure to ionizing radiation by recording, analyzing and disseminating the relevant information. Since 2001, Greek Atomic Energy Commission has established a committee with the mandate to provide advice, to keep records, to analyze and disseminate the experience gained in cases of unintended E/F exposure. During the period 2001-2011, the committee was consulted by 269 pregnant women undergone medical exposures. The conclusions from the relevant data analysis, as well as the experience gained are herein presented and discussed.