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Introduction Ionising radiation needs to be precisely evaluated since CT scan is the main radiological examination today. Biological effects caused by radiation are estimated with computational methods as it’s not possible to measure the real doses delivered directly to a specific organ. The DOSITRACE software is a Dose Archiving and Communication System (DACS) based on a new calculation method which allows a more reliable estimation of organ doses. The aim of this study was to compare our results with the results given by the VIRTUALDOSE [1] software using the Monte-Carlo method. Methods CTDIvol, current and rotation time for each acquisition were used to calculate organ doses (ICPR). Four CT protocols (abdomen-pelvis, chest-abdomen-pelvis, chest and thorax) were used with three different CT scans. Thirty patients were selected for each protocol. In total, CT scan exams were analysed and our results were compared with the ones obtained with the VIRTUALDOSE software. Results There was only a 20% difference in the estimation of organ doses between the VIRTUALDOSE and DOSITRACE software’s results which is not statistically significant. Conclusions We demonstrated that DOSITRACE is a reliable software in order to calculate organ doses.

Contexte L’utilisation des rayonnements ionisants est indispensable dans le domaine medical. Toutefois, ces rayonnements peuvent presenter un risque pour le patient ainsi que les professionnels de sante. Selon le rapport de l’ASN sur l’etat de la surete nucleaire et de la radioprotection en France en 2015 « 525 ESR ont ete enregistres dont 220 ont concerne la radiotherapie ou la curietherapie, 123 la medecine nucleaire, 100 la scanographie et 22 la radiologie interventionnelle ». Les guides 11 et 16 de l’ASN decrivent le processus de gestion des risques a mettre en place dans les etablissements de sante, base sur le retour d’experience a travers la declaration et l’analyse des evenements significatifs enregistres. Methode La RMP (Risk Management Platform) est utilisee en routine clinique dans les services de radiotherapie et de medecine nucleaire du groupe SENY. Le processus de gestion des risques est integre a la pratique clinique, selon deux methodes. Une methode preventive, grâce a l’outil AMDEC, permettant d’identifier les potentiels modes de defaillance, d’analyser leurs causes et leurs consequences. Les risques les plus importants sont identifies grâce au calcul de leur criticite. Afin de reduire ces risques, des plans d’action sont mis en place. La comparaison de la criticite residuelle a celle esperee permet de confirmer l’efficacite du plan d’action mis en place. Au niveau du Groupe SENY, une mise a jour de l’AMDEC se fait tous les ans. Une methode corrective, basee sur le retour d’experience et la mise en place de CREx (comite de retour d’experience), se base sur les declarations de tous les evenements precurseurs ou indesirables survenus dans les services. La criticite est aussi calculee pour chaque evenement et les plus critiques sont analyses en etudiant la chronologie des faits, les causes et les consequences de ces evenements. Cette analyse est assistee par un outil statistique. Des actions correctives et preventives sont determinees lors des reunions CREx mensuelles avant d’etre mises en place. Conclusion Notre retour d’experience lie a l’utilisation de la plateforme RMP en routine clinique au niveau du Groupe SENY, nous a permis d’assurer une conformite aux guides no 11 et 16 de l’ASN, une gestion des risques en temps reel, une assistance de nos professionnels de sante dans les demarches administratives, declaratives et reglementaires, ainsi qu’une amelioration continue de la qualite et la securite des soins.

Introduction To reduce exposure to the workers in interventional radiology, Collective Protection Equipment (CPE) are used (low lead curtains and their vertical extension, ceiling suspended screen …). For the same purpose, radio-attenuator soft screens (RADPAD®) have been developed. The objective of this study is to evaluate the influence of the CPE and the RADPAD® on the operator’s dosimetry in coronary angiography; we also measured patient’s skin-dose without and with the utilization of the RADPAD®. Methods Firstly, the interventional radiology equipment has been positioned at the tube incidence LAO 0°. The dose at different heights along the operator’s body (50, 75, 100, 125, 150 and 175 cm) was measured without the use of any CPE, and then by adding them successively (low curtains, vertical extension of the low curtains, ceiling suspended screens and then the radio-attenuator screen RADPAD®). Secondly, the skin dose of a phantom placed on the patient’s table was measured at three different distances from the ceiling screen, with and without RADPAD® at a tube voltage of 68 kVp in LAO 0° and then at 125 kVp in LAO 0° and LAO 30°. Results The use of the three CPE shows an attenuation of the radiation dose by 76% at the height of 175 cm along the operator’s body, it increases by 3.8% when using the RADPAD®. At low voltage, the use of the RADPAD® increases patient’s dose by 13% in the region near the ceiling screen. However, it attenuates the dose by 85.5% at 26 cm form this latter. At high voltage, the dose decreases at all of the three measure points; the effect of the RADPAD® varies depending on the distance from the screen and the tube angle. Conclusions Collective Protection Equipment are effective to decrease operator’s exposure in coronary angiography. The RADPAD® allows a significant reduction of the patient’s dose far the ceiling screen.

Introduction The department of interventional cardiology of Hopital Prive La Louviere describes the use of the DOSITRACE software for analyzing and optimizing radiation doses delivered to patients for five years. Methods 12874 procedures in the department of interventional cardiology with a Siemens Axiom Artis C-arm were collected with DOSITRACE software (from 2011 to 2016). Patient dose and examination parameters were recorded. The most common procedures are coronary angiography and coronary angiography without VG. The most radiative procedures are the coronary dilatation and CTO. Two alert levels are considered in function of risk. For weakly irradiating procedures: level 1 is twice the NRI (interventional Reference level), level 2 is four times the NRI. For highly irradiating procedures: level 1 is 300 Gy.cm2, level 2 is 600 Gy.cm2 (threshold at which deterministic effects would begin to appear). Alerts are studied over the five year evaluation period. Results The use of a DACS allows to reduce the interventional reference level. The NRI declined by 28.4% for the coronary angiography without VG and by 50.9% for the CTO. Conclusions This is the conclusion text. The use of DOSITRACE demonstrates decreased alerts, the dose optimization and risk reduction.

Introduction The aim of the study is to estimate, before intervention, the radiation dose that will be delivered to the patient during a recanalization of Chronic Total Occlusion (CTO). Relevant clinical indicators should be selected to predict, at best, the risk of deterministic effects and improve patient care. Methods 103 CTO procedures were performed in a department of interventional cardiology with a Siemens Artis Zee C-arm giving Air Kerma. The peak skin dose was measured for each intervention, using radiochromic films. Patient parameters, such as gender, age weight and height were recorded. The complexity index (J-CTO score) which is specific to each intervention, was determined by the cardiologist. A correlation study has clarified the impact of these indicators on the dose. A predictive model of the dose to the patient was found. Results Of the 103 patients studied, 5 were excluded from the study for clinical reasons, 2 others because radiochromic films were outside of the exposure field. Finally, 96 2D dose maps were used for the study. The factors showing the highest correlation with the peak skin dose are patient diameter and J-CTO score. The prediction model is therefore based on these two parameters. The comparison between the predicted skin dose and measured skin dose showed an average difference of 0.85 ± 0.55 Gy for doses less than 6 Gy. The average difference between Air-Kerma and peak skin dose is about 1.66 Gy ± 1.16 Gy. Conclusions An initial estimate of the skin dose to the patient is given prior to the start of the intervention. This indication helps the cardiologist to work effectively and safely. This predicted dose is more accurate than the estimate provided by the air-kerma.

Purpose/objective : We tried to reduce the number of local recurrences after surgery and external beam irradiation (EBI) in carcinoma of the oral cavity, when margins were positive or close. Material and methods : From 1980 to 1992, we treated 97 cases of carcinomas of the oral cavity by postoperative brachytherapy. Surgery was combined with EBI + brachytherapy in 51 cases and with brachytherapy alone in 46 cases. We treated 29 T1, 34 T2, 30 T3T4 and four Tx (73% were N0 at first examination and 23% had positive nodes). The type of surgery is analysed. Brachytherapy was performed in one or two planes along the surgical scar. If the mandibular rim was resected, especially when the tongue or the remaining floor were sutured to the internal face of the inferior lip or to the buccal mucosa, the bridge technique was used. To decrease the dose to the inferior part of the mandible, the bridge was modified thanks to experimental dosimetry. Results : At 5 years, the local control (LC) is 89%, the locoregional control (LRC) 82%, the specific survival (SS) 74% and the overall survival (OS) 67%. Complications : We noted 19% of grade 1 (minor), 12% of grade 2 (moderate) and 6% of grade 3 (major) complications. Conclusion : Compared with the results of the literature, we think that postoperative brachytherapy can improve classical radiosurgical results in selected cases with a risk of local recurrence.

Introduction This study aims at identifying the high-dose procedures in a cardiology department and to find correlation factors to predict the risk of occurrence of deterministic effects in terms of relevant indicators. Materials and methods A working group composed of medical physicists, interventional cardiologists and Radiation Safety Officer was created. DOSITRACE platform, allowing automated data collection and historical patient dosimetry was installed. A couple of approaches have been implemented: a risk management approach that is oriented toward a prevention-based perspective and another risk management approach that is oriented toward a curative-based perspective. Results The use of DOSITRACE in clinical routine has enabled us to identify the recanalization of Chronic Total Occlusion (CTO) as the one which may deliver the highest patient radiation dose. Subsequently, the working group has become interested in this procedure to figure out the factors that determine the escalation of the radiation dose delivered to the patient. The results are as follows: ● An average reduction of 15% of the radiation dose delivered to the patient through a process of optimization of the dose was obtained. ● A correlation between the BMI, the beam angulation and patient radiation dose was found. ● For the procedure for recanalization of CTO, an increase in dose in terms of the complexity factor J-CTO score was highlighted: Score = [0, 1, 2, 3, 4]: Average Dose Area Product (DAP) = [152,160,244,299,418 Gy cm2]. In parallel, the group has worked on the equivalent dose effect of the entrance skin doses delivered for the repeated interventions in order to predict the occurrence of deterministic effects due to cumulative dose. A method, published by the team Balter et al. in 2010 was implemented in DOSITRACE. For the case of the repeated recanalization of CTO, we have implemented an innovative predictive risk method depending on the J-CTO score and BMI. A radiochromic film dosimetry was implemented in a systematic manner for CTO procedures to measure precisely the maximum skin dose delivered to the patient (Peak Skin Dose PSD), a real risk indicator. Conclusion This project has enabled us to identify the high-dose procedures and to implement methods to predict the risk of deterministic effects occurring, both based on the cumulating PSD for the repeated recanalization of CTO interventions, and the J-CTO Score.