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Purpose Medical Physics Department (MPD) of APSS Trento has written a proposal for technical requirements of X-ray Personal Protective Equipment (PPE) (aprons, skirts, thyroid collars and accessories), concerning a tender and a full service contract, including cleaning and quality controls (QCs). Methods and materials Concerning a tender, PPEs must comply with laws and regulations [1] , [2] , [3] , [4] , [5] . They must be accompanied by a declaration of lack of lead, latex and PVC (or the phthalates percentage). The supplier must provide a sampling of PPE in various sizes to test the fit, an attenuating sampling material (0.25, 0.35 and 0.50 mmPbeq) in order to perform transmission measurements at the voltages of interest (range of 50–150 kV), products and methods for cleaning. All PPEs must be accompanied by a data sheet and informative documents that report all the technical features, chemical composition, usage method, storage, cleaning, inspections frequency and requirements for disposal. In addition, the full service contract must include: -providing conditions; -cleaning/disinfection methods; -QC by the supplier (tactile and visual controls, functionality controls, X-ray assessments, evaluation of the permanence of the attenuation features); -the replacement mode; -the PPEs traceability; -storing in a database all the PPE data, QCs results and images, cleaning and replacement data. Results After two years of experience, the quality assurance for PPEs is performed through a full service contract supplying about 300 new PPEs and ensuring cleaning and quality controls. Conclusion MDP is responsible of management and quality assurance for X-ray radiation protection PPEs (about 700 units).This technical and organizational proposal approach guarantees an adequate quality standard of PPEs management.

Purpose Report the experience of Medical Physics Department of APSS Trento in coordinating the assessments and radioactive radon gas mitigations of medical clinics, complying with laws [1] , [2] . Methods and materials 42 measurement points were chosen in the workplaces at the lower floors (undergrounds, basements, ground floors) of the various buildings that were representative of the most critical situations with respect to aeration. Radon concentrations have been measured for one year through all workplaces using passive detectors, i.e. electrets giving integrated values, and also during Radon mitigation, using active detector, i.e. a Lucas scintillation cell monitor, allowing temporary monitoring. For each worker the effective dose was estimated applying the conversion factor 3·10−9 Sv·m3/Bq ·h [2] . Based on Radon concentration measurements and effective dose estimations, an evaluation of Radon mitigation has been undertaken (Fig. 1), adopting organizational or structural approach. Results The exceeding of the action levels [2] have been found only at medical clinics of Pinzolo and Levico, in terms of both concentration and effective dose. At Pinzolo a Radon concentration of 1745 Bq/m3 was measured, while at Levico it was found to be 1216 Bq/m3. Two different remedial actions were adopted. At Pinzolo an organizational approach was undertaken. Workers were transferred to another workplace at ground floor with a formwork for ventilated foundation, where the Radon concentration was 160 Bq/m3. Instead at Levico, considering also additional measurements in other places of the same building, an active soil depressurization through mechanical ventilation has been realized, leading to a Radon concentration less than 110 Bq/m3. The optimization of ventilation system was done using active dosimeters. Conclusion Although Radon mitigation is a challenging task, the adopted solutions proved to be effective.

Dose assessment in computed tomography is nowadays based on indicators such as the weighted computed tomography dose index (CTDIw) and the volume-weighted computed tomography dose index (CTDIvol), both measured only on single-axial scans. The aim of this study is to extend the set of CT protocols suitable in CTDIvol,w evaluation and therefore to perform measurements directly on clinical CT scans. With this purpose, the present work follows the methodology proposed by the American Association of Physicists in Medicine in the Report No. 111 and focuses on the central cumulative dose DL(0), which predicts CTDIvol,w values for scan length equal to 100 mm. All measurements performed with ion chamber and gafchromic films suggest that it is possible to achieve accurate CTDIvol,w values without selecting single-axial scans tailored to dosimetry. Therefore, it is not always necessary to split dosimetric and clinical CT scanner set-up.