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Purpose To compare skin dose values and their spatial distribution obtained with the radiation dose tracking software with measurements on gafchromic films on phantom and patients. Methods In NEXO[DOSE]® (Bracco, Milan) the distribution of skin dose of interventional radiology procedures is calculated on the surface of a mathematical torso phantom using exposure parameters of each irradiation event from the Radiation Dose Structured Report and additional angiography-specific information (table and mattress attenuation, KAP correction factor and tube position relative to the table). The skin dose map and the peak skin dose (PSD), i.e. the maximum cumulative dose value, are displayed in the software. To test the accuracy of the algorithm we irradiated GAFCHROMIC XR-RV3 films wrapped on a phantom with different test fields using a Philips Integris Allura FD20 angiography. Absolute dose values and geometric accuracy of the phantom dose map calculated by NEXO[DOSE]® were compared with the film. The tool was also clinically tested by placing a film on the patient’s back during interventional embolization procedures at the beam entrance side. Results In the phantom, the geometric accuracy calculated by NEXO[DOSE]® was within 10% (Fig. 1). the cumulative dose was in good agreement for high dose fields ( Table 1 ). PSD agreement was within 15%. During clinical procedures, films confirmed that NEXO[DOSE]® can estimate the dose distribution on the patient’s skin even for more complex irradiation geometries and calculated PSD differs less than 15% from the film value. Conclusions NEXO[DOSE]® provides an estimation of the geometric distribution of skin dose and PSD within 15% and thus it can help in the dosimetric management of the procedures.

Purpose To use NEXO[DOSE], a Radiation Dose Index Monitoring system, to collect and analyse dosimetric data to drive the optimization of the interventional radiology procedure for prostatic artery embolization (PAE). Methods NEXO[DOSE] extracts geometric (primary and secondary angles, table height) and dosimetric (irradiation type, KAP, voltage, filter) parameters from the Radiation Dose Structured Report, and calculates a skin dose map. NEXO[DOSE] separately lists the dose contribution from the acquisition mode and the fluoroscopy. In our institution, the PAE interventional procedure involved high Kerma Area Product (KAP) compared to other angiographic protocols and was associated with high risk of skin lesions. A low dose protocol was introduced and phantom characterization, i.e. entrance dose and image quality (LCD), was assessed on 24 to 30 cm PMMA phantom to better represent the patient geometry, considering that the highest dose contributions came from events with oblique angles. After optimization, patient dose was monitored using KAP and peak skin dose. Results We retrospectively analysed the exposure values of 84 patients, using NEXO[DOSE]. The acquisition dose in PAE is 70% of the total procedure: the first step was the introduction of an acquisition protocol with low entrance detector dose. The frame rate was reduced from 3 to 2 fps, and additional X-ray filtration of 1 mmAl + 0.1 mmCu was added. The fluoroscopy frame rate was also reduced from 15 to 7.5 fps. Entrance dose at the phantom surface was reduced by 49%, while the LCD reduction was 30% for details dimensions from 0.5 to 6 mm. The physicians assessed the loss of image quality to be acceptable. After optimization PAE procedures showed a 60% KAP reduction and a 49% peak skin dose reduction. Conclusions A RDIM software is a useful tool to highlight high dose procedures and to understand what parameters to modify, after a multidisciplinary team discussion.

Purpose To use NEXO[DOSE]; a Radiation Dose Index Monitoring system, to collect and analyse dosimetric data to drive the optimization of interventional radiology procedure for prostatic artery embolization (PAE). Methods NEXO[DOSE] extracts geometric (primary and secondary angles, table height) and dosimetric (irradiation type, KAP, voltage, filter) parameters from the Radiation Dose Structured Report, and calculates a skin dose map. This software separately lists the dose contribution from the acquisition mode and the fluoroscopy: this can help to quantify the contribution of the two acquisition types. We identify in our institution the PAE angiographic procedure as a high dose procedure, with high Kerma Area Product (KAP) compared to other interventional protocols. It was associated with high risk of skin lesions. A low dose protocol was introduced and phantom characterization, i.e. entrance dose and image quality (LCD), was assessed on various thickness of PMMA. It was necessary to use 30 cm of PMMA to better represent the patient geometry, considering that, in this procedure, the highest dose contributions came from events with oblique angles. After optimization, patient dose was monitored using KAP and peak skin dose. Results We retrospectively analysed the exposure values of 84 patients, using NEXO[DOSE]. The acquisition dose in PAE is 70% of the total procedure: the first step was the introduction of an acquisition protocol with low entrance detector dose. The frame rate was reduced from 3 to 2 fps and additional X-ray filtration of 1 mm Al + 0.1 mm Cu was added. The fluoroscopy frame rate was also reduced from 15 to 7.5 fps. In the phantom the entrance dose was reduced by 49% and the LCD reduction was 30% for details dimensions from 0.5 to 6 mm. The physicians assessed the loss of image quality to be acceptable. The clinical procedures had a 60% KAP reduction and a 49% PSD reduction. Conclusion The optimization process of PAE procedure led to a significant reduction of patient dose and a degradation of image quality that was judged satisfactory from physicians. This was the result of a multidisciplinary team work (physicians, technicians and medical physicists).