Statement of the Italian Association of Medical Physics (AIFM) task group on radiation dose monitoring systems.

The evaluation of radiation burden in vivo is crucial in modern radiology as stated also in the European Directive 2013/59/Euratom-Basic Safety Standard. Although radiation dose monitoring can impact the justification and optimization of radiological procedure, as well as effective patient communication, standardization of radiation monitoring software is far to be achieved. Toward this goal, the Italian Association of Medical Physics (AIFM) published a report describing the state of the art and standard guidelines in radiation dose monitoring system quality assurance. This article reports the AIFM statement about radiation dose monitoring systems (RDMSs) summarizing the different critical points of the systems related to Medical Physicist Expert (MPE) activities before, during, and after their clinical implementation. In particular, the article describes the general aspects of radiation dose data management, radiation dose monitoring systems, data integrity, and data responsibilities. Furthermore, the acceptance tests that need to be implemented and the most relevant dosimetric data for each radiological modalities are reported under the MPE responsibility.

A single phantom, a single statistical method for low-contrast detectability assessment.

PURPOSE: The assessment of low-contrast-details is a part of the quality control (QC) program in digital radiology. It generally consists of evaluating the threshold contrast (Cth) detectability details for different-sized inserts, appropriately located in dedicated QC test tools. This work aims to propose a simplified method, based on a statistical model approach for threshold contrast estimation, suitable for different modalities in digital radiology. METHODS: A home-madelow-contrast phantom, made of a central aluminium insert with a step-wedge, was assembled and tested. The reliability and robustness of the method were investigated for Mammography, Digital Radiography, Fluoroscopy and Angiography. Imageswere analysed using our dedicated software developed on Matlab®. TheCth is expressed in the same unit (mmAl) for all studied modalities. RESULTS: This method allows the collection of Cthinformation from different modalities and equipment by different vendors, and it could be used to define typical values. Results are summarized in detail. For 0.5 diameter detail, Cthresults are in the range of: 0.018-0.023 mmAl for 2D mammography and 0.26-0.34 mmAl DR images. For angiographic images, for 2.5 mm diameter detail, the Cths median values are 0.55, 0.4, 0.06, 0.12 mmAl for low dose fluoroscopy, coronary fluorography, cerebral and abdominal DSA, respectively. CONCLUSIONS: The statistical method proposed in this study gives a simple approach for Low-Contrast-Details assessment, and the typical values proposed can be implemented in a QA program for digital radiology modalities.

Abdominal Aorta Angiosarcoma after Endovascular Aneurysm Repair.

Primary tumors originating within the wall of the arteries are rare and they frequently manifest late, making effective treatment a challenge. We describe here a case of Abdominal Aorta AngioSarcoma masqueraded as an infected EndoVascular Aortic Repair. The knowledge of this pathology from vascular surgeons and radiologist is crucial, because a prompt diagnosis and treatment can improve the prognosis.

Provision of Italian diagnostic reference levels for diagnostic and interventional radiology.

OBJECTIVES: The diagnostic reference level (DRL) is a useful tool for the optimisation of medical exposures. Thus, a Working Party coordinated by the Italian National Institute of Health and the National Workers Compensation Authority has been formed to provide Italian DRLs, for both diagnostic and interventional procedures, to be used as appropriate for the implementation of the 2013/59 European Directive into the national regulation. MATERIALS AND METHODS: The multidisciplinary Working Party was formed by professionals involved in diagnostic and interventional radiology medical exposures and started from a critical revision of both the literature and the results of previous Italian surveys. The procedures were divided into five sections for adult (projection radiography, mammography, diagnostic fluoroscopy, CT and interventional radiology) and two sections for paediatric patients (projection radiography and CT). The provided DRL values have been identified for "normal" adult patients and for age-classes of paediatric patients. RESULTS: Some of the DRL values provided by the Working Party are reported in this study as an example, divided by adult/paediatric patients, radiological technique and examination: specifically, DRLs for new radiological practices and new dose quantities as DRLs metric were introduced. The median value (rather than the mean) for each procedure, derived from a sample of patients, has to be compared with the corresponding DRL value, and dosimetric data related to a minimum number of patients should be collected for each examination. CONCLUSIONS: The approach to the definition and use of DRLs through guidelines of national Authorities in collaboration with scientific Associations should simplify the periodical updating and could be useful for keeping the optimisation of medical exposures faithful to the development of radiological practice.

Patient dose in angiographic interventional procedures: A multicentre study in Italy.

PURPOSE: The Council Directive 2013/59/EURATOM considers interventional radiology to be a special practice involving high doses of radiation and requiring strict monitoring to ensure the best quality assurance programs. This work reports the early experience of managing dose data from patients undergoing angiography in a multicentre study. MATERIALS AND METHODS: The study was based on a survey of about 15,200 sample procedures performed in 21 Italian hospitals centres involved on a voluntary basis. The survey concerned the collection of data related to different interventional radiology procedures: interventional cardiology, radiology, neuroradiology, vascular surgery, urology, endoscopy and pain therapy from a C-Arm and fixed units. The analysis included 11 types of procedures and for each procedure, air-kerma, kerma-area product and fluoroscopy time were collected. RESULTS: The duration and dose values of fluoroscopic exposure for each procedure is strongly dependent on individual clinical circumstances including the complexity of the procedure; the observed distribution of patient doses was very wide, even for a specified protocol. The median values of the parameters were compared with the diagnostic reference levels (DRL) proposed for some procedures in Italy (ISTISAN) or internationally. This work proposes local DRL values for three procedures. CONCLUSION: This first data collection serves to take stock of the situation on patient's dosimetry in several sectors and is the starting point for obtaining and updating DRL recalling that these levels are dependent on experience and technology available.

Patient dose during carotid artery stenting with embolic-protection devices: evaluation with radiochromic films and related diagnostic reference levels according to factors influencing the procedure.

PURPOSE: To measure the maximum entrance skin dose (MESD) on patients undergoing carotid artery stenting (CAS) using embolic-protection devices, to analyze the dependence of dose and exposure parameters on anatomical, clinical, and technical factors affecting the procedure complexity, to obtain some local diagnostic reference levels (DRLs), and to evaluate whether overcoming DRLs is related to procedure complexity. MATERIALS AND METHODS: MESD were evaluated with radiochromic films in 31 patients (mean age 72 ± 7 years). Five of 33 (15 %) procedures used proximal EPD, and 28 of 33 (85 %) procedures used distal EPD. Local DRLs were derived from the recorded exposure parameters in 93 patients (65 men and 28 women, mean age 73 ± 9 years) undergoing 96 CAS with proximal (33 %) or distal (67 %) EPD. Four bilateral lesions were included. RESULTS: MESD values (mean 0.96 ± 0.42 Gy) were <2 Gy without relevant dependence on procedure complexity. Local DRL values for kerma area product (KAP), fluoroscopy time (FT), and number of frames (NFR) were 269 Gy cm(2), 28 minutes, and 251, respectively. Only simultaneous bilateral treatment was associated with KAP (odds ratio [OR] 10.14, 95 % confidence interval [CI] 1-102.7, p < 0.05) and NFR overexposures (OR 10.8, 95 % CI 1.1-109.5, p < 0.05). Type I aortic arch decreased the risk of FT overexposure (OR 0.4, 95 % CI 0.1-0.9, p = 0.042), and stenosis ≥ 90 % increased the risk of NFR overexposure (OR 2.8, 95 % CI 1.1-7.4, p = 0.040). At multivariable analysis, stenosis ≥ 90 % (OR 2.8, 95 % CI 1.1-7.4, p = 0.040) and bilateral treatment (OR 10.8, 95 % CI 1.1-109.5, p = 0.027) were associated with overexposure for two or more parameters. CONCLUSION: Skin doses are not problematic in CAS with EPD because these procedures rarely lead to doses >2 Gy.

Neuroembolization may expose patients to radiation doses previously linked to tumor induction.

OBJECTIVE: Epidemiological studies indicate a link between low-dose irradiation (<10,000 mGy) to the head and the local occurrence of tumors after decades of delay. Comparable radiation doses can be reached during neuro-endovascular procedures (NEP), but the incidence of similar exposures has not been completely delineated. We compared the levels of radiation to the head measured during NEP to those reported for patients developing radiation-induced cancers. METHODS: In our prospective study we determined the cumulative maximum entrance skin doses (MESD) and the incidence of epilation in 107 consecutive patients submitted to NEP between 2003 and 2007. We also extensively searched the literature and compared our results with the data we found. RESULTS: The cumulative MESD due to NEP was above 3,000 mGy (range 3,101-5,421 mGy) in 18 patients. In 22 we observed partial epilation within 10 weeks from the initial NEP. Sixty cases of epilation after NEP have been previously reported in the literature. The average of the reported MESD was 4,241 mGy (range 2,000-6,640 mGy). CONCLUSION: Physical dosimetry and the incidence of partial epilation indicate that about one fifth of the patients submitted to NEP received radiation doses comparable to those linked to the occurrence of tumors. The potential risks of developing tumors after a long delay, when compared to the immediate benefits of endovascular treatment of aneurysm and arteriovenous malformations (AVM) of the brain, do not counterindicate NEP, but increased awareness of the risk should help physicians and patients to make a fully informed decision when other treatments are available.

Radiochromic films for improved evaluation of patient dose in liver interventions.

PURPOSE: To investigate a method for evaluation of the maximum skin dose (MSD) of radiation in patients undergoing interventional radiology procedures in the liver. MATERIALS AND METHODS: Transarterial chemoembolization, transarterial embolization, portal vein embolization, and biliary interventions were the procedures considered in this study. Ninety procedures in 70 patients were studied. The complexity of the biliary interventions was taken into account during the analysis. The MSD was measured with use of GAF chromic XR type R films, whereas the dose-area product (DAP) was measured by a transmission chamber. RESULTS: The MSD was measured in a group of 19 patients. The coefficient of the interpolation line between the skin dose and the DAP (0.0051 cm(-2)) was determined. An approximated value of MSD from the DAP for the remaining 71 procedures was estimated by means of an interpolation line. The mean MSD in the endovascular procedures was 4.4 Gy; for the three different levels of complexity of the biliary procedures, the mean MSDs were 0.4, 1.2, and 3 Gy, respectively. CONCLUSIONS: Radiochromic films are an easy-to-use and efficient method for measuring skin entrance radiation dose and have the advantage of providing information on the MSD as well as the distribution of radiation to the skin. In light of these results, the authors suggest recording the dose for biliary and endovascular procedures as indicated by the International Commission on Radiological Protection and the United States Food and Drug Administration.