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• Cardiologists in catheterization procedures can receive high eye-lens equivalent doses. • Individual eye-lens dosimetry is recommended for highly exposed workers. • Accurate uncertainty assessment is needed in eye-lens dosimetry. To perform a multi-centre survey on the eye lens equivalent dose absorbed by primary interventionalist during catheterization procedures, using a personal dosimeter placed close to the eye lens. 15 different cardiologists working in 3 different centers, for a total of 5 operating rooms were enrolled. All of them were provided with a single thermoluminescent dosimeter positioned on the inner side of the temples of eyeglasses. The dose monitoring, performed on a two-months basis, started in 2016 and is still running. All dose measurements were performed by a ISO 17025 standard accredited dosimetry service thus providing certified uncertainties as well. Correlation of eye lens and wrist dose with KAP was also investigated. A total number of 101 eye lens measurements were performed. Annual eye lens dose estimation was obtained for all 15 surgeons (mean, mode, range, standard deviation: 10.8, 8, 4.9–27.3, 5.6 mSv, respectively). Uncertainties on annual eye lens dose estimations ranged between 10% and 20%. No significant correlation was found between eye lens dose and KAP. Cardiologists involved in catheterization procedures may receive annual eye lens doses close to the ICRP 118 dose limit and thus individual monitoring with a dedicated dosimeter should be carried out. Uncertainty assessment play a relevant role in eye lens equivalent dose estimation to ensure not to exceed dose limit. [ABSTRACT FROM AUTHOR]

Purpose A retrospective analysis of VMAT treatments delivered in our center since 2015 has been performed by studying the correlation between the results of pretreatment dosimetric evaluation and different parameters related to the complexity of the treatment plans. Districts considered for this study included Head & Neck, Pelvis and Prostate. Methods 3D pretreatment dose verification has been performed by OCTAVIUS 4D (PTW) with matrix 729 on a Linac Elekta Synergy Agility. Analysis of volumetric 3D gamma has been done by using thresholds of 3%, 3mm and 10%. The treatment plans have been created with the TPS Pinnacle 9.10; since 2016, the autoplanning module was also considered. The complexity of each plan has been evaluated by a complexity index [1] and the number of MU. Within- and across- districts analysis has been performed by Receiver operating characteristic (ROC) curves. Results For both complexity index and number of MU, our analysis identified a set of district-specific threshold values able to predict the success of pretreatment dosimetric evaluation (3D gamma > 90%). Conclusions Our analysis (for our configuration: Elekta Agility, Pinnacle 9.10 with autoplanning module, OCTAVIUS 4D with 729 matrix) suggests that, especially for Head&Neck and Pelvi, it’s possible to predict the quality of a treatment plan on the basis of the corresponding complexity index and the number of MU. If validated prospectively, this analysis suggests the possibility to evaluate the quality of the plan before performing its 3D dose verification. [ABSTRACT FROM AUTHOR]

Purpose The immediate consequence of the new equivalent dose limit for the lens of the eye was a change in the international basic safety standards (BSS) and in the European BSS and the adoption of new limit. For the Catheter Laboratory Procedure, available literature mentions a poor correlation between chest dose measurements and eye lens doses. Aim of the study is to evaluate, if there is any, the correlation between clinical and technical parameters and operator lens dose. Methods Operators, who have used ceiling suspended screen, were monitored throughout thermoluminescence dosimeters (TLDs). The accredited laboratory pass EURADOS intercomparison on Eye Lens in 2016, using TLD calibrated in Hp(0.07), therefore also Hp(0.07) dosimeters are suitable for this application. Chest TLD dosimeter were placed under the lead apron at chest level, hand TLD on the bracelet and the lens TLD was positioned under the shielded glasses. Patient dose values (kerma area product), clinical and technical parameters, as number and type of procedures, were recorded and analyzed. Results The lens dose for main operator in Catheterization Lab of the first 3 centres enrolled are reported. As expected, hands dose depends on the type of procedure performed. Despite this, it is possible to find a weak correlation between the hands dose and the total number of procedures performed by the operator. The chest dose seems to be a completely unrelated parameter with the lens dose. The lens dose does not correlate with the parameters analyzed. Conclusions Lens dose monitor is an extremely complex features. The position of the dosimeter, the type of procedure, the operator experience, and also clinical condition of the patient strongly affect that parameter. Chest and bracelet dosimeters appear not to be adequate for efficient lens dose monitoring. [ABSTRACT FROM AUTHOR]