Dose-Tracking Software: A Retrospective Analysis of Dosimetric Data in CT Procedures.

ABSTRACT: The increasing use of ionizing radiation in healthcare is causing growing alarm about radiation protection of patients and the doses they receive during procedures. Radiation dose assessment for patients in radiodiagnostic procedures is the subject of interest in view of the recent Italian D.Lgs 31 July 2020, n. 101 (Decreto Legislativo 31 luglio 2020, n. 101) and one of its most important focuses is the prescription to provide patient exposure information as an integral part of the examination report. Dose monitoring systems are therefore essential for the collection of the dosimetric data. In order to analyse potential and critical issues of these software, different systems, adopted at the Antonio Cardarelli Hospital in Naples, were employed. Data extracted from the DoseWatch software (GE Healthcare) and Gray Detector (EL.CO. S.r.l. Healthcare Solutions, Italy) and relating to several protocols adopted for computed tomography (CT), were retrospectively analysed for the purpose of identifying critical issues in the data acquisition and recording phase, comparing with Italian nationwide diagnostic reference levels (DRLs), as provided for in regulatory provisions for radiation safety. Multiphase examinations were also included in this study. Once the distributions of volumetric CT Dose Index (CTDIvol) and dose-length product (DLP) were determined for each acquisition phase and total DLP (DLPtot) for each examination, the 25th, 50th and 75th percentiles were calculated for each distribution and then compared with the relevant Italian nationwide DRLs. In addition, to improve protocol optimization and dose reduction the magnitude of the CT acquisition settings chosen in each procedure was evaluated. In conclusion, these systems allow accurate analysis of radiation dose according to equipment and protocol over time. For the application of optimization measures, a constant use of the dose tracking software is required, which can be translated into actions on scan parameters and prospective data analysis.

CHARACTERIZATION OF A SMALL FOV PORTABLE GC: MediPROBE.

In this work, we evaluated the performance of the prototype SFOV MediPROBE developed at the University of Naples Federico II through the protocol proposed by (Bhatia B.S., Bugby S.L., Lees J.E., Perkins A.C. A scheme for assessing the performance characteristics of a small field of-view gamma cameras. Physica. Medica., 31 (1), pp. 98-103. (2015) doi: 10.1016/j.ejmp.2014.08.004). We extensively investigated a new device configuration where the pinhole collimator was placed outside the housing of the probe, in order to increase the system spatial resolution, and the pixel size was doubled, in order to reduce the charge sharing effect. The experimental measurements show that the spatial resolution is enhanced by only about 10%, but the sensitivity decreases strongly. Therefore, the trade-off between these two features does not seem to be advantageous. In addition, our experiments suggest that the charge sharing effect is not completely canceled. Despite these results, the features of this device appear suitable for intraoperative surgical survey. We aim to use this device in the clinical practice for the intraoperative imaging of lymph nodes, breast, thyroid and parathyroid tumors.

Predelivery uterine arteries embolization in patients affected by placental implant anomalies.

PURPOSE: The aim of this study is to report on a single center experience of managing patients affected by placenta previa major and/or accretism by embolizing uterine arteries immediately before the cesarean delivery to reduce blood loss and secondary the rate of hysterectomies. MATERIALS AND METHODS: Sixty-nine patients have been prospectively enrolled. Inclusion criteria were radiological diagnosis of placenta anomalies and risk factors for peri/postpartum hemorrhage. The delivery was electively scheduled between the 35th week and the 36th week of pregnancy. The embolization procedure was performed in the gynecological operating room with a mobile C-arm by injecting calibrated microparticles 500-700 µm. A contrast-enhanced MRI was acquired in a subgroup of 10 patients 6 months after the delivery to evaluate the uterine wall status. RESULTS: Hysterectomy had been performed in 43.5%; 52.2% did not require blood transfusions; 1.2 blood units per patient had been meanly transfused. The mean fluoroscopy beam-on time was 195 s per patient. The mean uterine dose was 26.75 mGy. No pH anomalies were measured from the umbilical cord blood; the Apgar score at 5 min was ≥8. The analysis of the neuro-developmental milestones showed normal cognitive development in all children at 6 months. The uterine wall enhancement evaluated with contrast-enhanced MRI 6 months after the embolization procedure showed preserved myometrial perfusion without area of necrosis. CONCLUSIONS: In this series of patients, the predelivery uterine arteries' embolization was a safe and effective procedure; this may represent a technical alternative that interventional radiologists can consider when facing this challenging scenario.