SESAME: A TOOL FOR NUMERICAL DOSIMETRIC RECONSTRUCTION OF PATIENTS OVEREXPOSURES IN INTERVENTIONAL RADIOLOGY.

Radiation overexposure accidents are rare but can have severe health consequences. Evaluating the dose received by the patient is a crucial step in the medical management. For that purpose, for more than 15 years, IRSN has been developing an in-house tool named SESAME for the numerical reconstruction of radiological accidents due to external sources. Recently, two new functionalities were implemented in SESAME to allow accurate reconstructions of interventional radiology (IR) overexposures. The experimental validation of SESAME for the reconstruction of overexposures in IR is presented. First, an anthropomorphic dummy equipped with dosemeters was irradiated following conditions similar to a fluoroscopically guided interventional procedure. Then the procedure was simulated using SESAME. Finally measured doses were compared to calculated doses. Even with a limited amount of data available, SESAME can provide valuable dose information for the medical team in charge of the patient, such as skin dose mapping and dose distribution in depth.

EYE LENS RADIATION EXPOSURE OF WORKERS DURING MEDICAL INTERVENTIONAL PROCEDURES AND SURGERY.

To evaluates the eye-lens radiation exposure of workers during medical interventional procedures and surgery in a military hospital as well as of the equine veterinarians. The measures represent the exposure in a normal workload schedule of ninety randomly selected workers over a 3-month period, extrapolated to 1 year. The eye-lens dosemeters were placed near the eye closest to the radiation source (Carinou, E., Ferrari, P., Bjelac, O. C., Gingaume, M., Merce, M. S. and O'Connor, U. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H p (3) monitoring. A 2015 review. J. Radiol. Prot. 2015;35(3): R17-R34). Three models of eye-lens dosemeters (Dosilab, Landauer and IRSN) were assessed in term of ergonomics. The annual estimation of eye-lens doses did not reach the annual dose limit of 20 mSv revised by the ICRP, ranged from 0.00 to 18.12 mSv with a mean of 0.96 ± 2.28 mSv. However, these results cannot be representative of a heavy workload or incident situations for which radiation exposure to the eye-lens could exceed this limit. The IRSN dosemeter model was considered the most convenient.

DosiKit, a New Portable Immunoassay for Fast External Irradiation Biodosimetry.

DosiKit is a new field-radiation biodosimetry immunoassay for rapid triage of individuals exposed to external total-body irradiation. Here, we report on the validation of this immunoassay in human blood cell extracts 0.5 h after in vitro exposure to 137Cs gamma rays, using γ-H2AX analysis. First, calibration curves were established for five donors at doses ranging from 0 to 10 Gy and dose rates ranging from ∼0.8 to ∼3 Gy/min. The calibration curves, together with a γ-H2AX peptide scale, enabled the definition of inter-experimental correction factors. Using previously calculated correction factors, blind dose estimations were performed at 0.5 h postirradiation, and DosiKit performance was compared against concomitant dicentric chromosome assay (DCA), the current gold standard for external irradiation biodosimetry. A prototype was then assembled and field tested. We show that, despite significant inter-individual variations, DosiKit can estimate total-body irradiation doses from 0.5 to 10 Gy with a strong linear dose-dependent signal and can be used to classify potentially exposed individuals into three dose ranges: below 2 Gy, between 2 and 5 Gy and above 5 Gy. The entire protocol can be performed in 45 min, from sampling to dose estimation, with a new patient triaged every 10 min. While DCA enables precise measurement of doses below 5 Gy, it is a long and difficult method. In contrast, DosiKit is a quick test that can be performed directly in the field by operational staff with minimal training, and is relevant for early field triage and identification of individuals most likely to experience acute radiation syndrome. These findings suggest that DosiKit and DCA are complementary and should be combined for triage in a mass scale event. While the proof-of-concept reported here validates the use of DosiKit at 0.5 h postirradiation, further studies are needed to calibrate and evaluate the performance of the DosiKit assay at longer times after irradiation.

Is there still a benefit to operate appendiceal abscess on board French nuclear submarines?

Appendicular abscess occurred in 14.2% of patients presenting acute appendicitis. Management of these patients remains controversial, ranging from an emergency appendectomy to a nonoperative treatment. On board French nuclear submarines, the usual treatment for all cases of appendiceal masses, including both appendicitis and appendiceal abscess, is an appendectomy. In the past 5 years, the introduction of ultrasonography (US) on board has enabled the diagnosis of appendiceal abscess with a high rate of accuracy, and the latest studies show that nonoperative treatment is an alternative approach. This nonsurgical treatment, based on intravenous administration of antibiotics, is successful in about 93% of the patients. Failure of nonsurgical treatment is a reliable indication of percutaneous drainage. The proportion of adult patients who need percutaneous drainage of abscesses is about 27%. A successful primary nonoperative treatment may or may not be followed by interval appendectomy at the conclusion of the patrol. Nonsurgical treatment is associated with a significantly lower morbidity than surgery. Considering that the on-board surgical facility is limited, nonsurgical treatment appears to be the best approach for treating a sailor with an appendiceal abscess during a submarine patrol mission.