Establishing Local Diagnostic Reference Levels in IR Procedures with Dose Management Software.

PURPOSE: To obtain local diagnostic reference levels (DRLs) in diagnostic and therapeutic IR procedures with dose management software to improve radiation protection. MATERIALS AND METHODS: Dose data of various vascular and nonvascular IR procedures performed within 18 months were collected and analyzed with dose management software. To account for different levels of complexity, procedures were subdivided into simple, standard, and difficult procedures as graded by interventional radiologists. Based on these analyses, local DRLs (given as kerma-area product [KAP]) were proposed. Comparison with dose data of others was conducted, and Spearman correlation coefficients were calculated to evaluate relationships between dose metrics. RESULTS: Analysis included 1,403 IR procedures (simple/standard/difficult, n = 346/702/355). Within the same procedure, KAP tended to increase with level of complexity. Overall, very strong correlation between KAP (Gy ∙ cm2) and cumulative air kerma (KA,R; Gy) was observed, and moderate to strong correlation between KAP and time and KA,R and time was observed. For simple procedures, strong correlation was seen between KAP and time and KA,R and time; for standard and difficult procedures, only moderate correlation was seen. Correlation between KAP and time and KA,R and time was strong in nonvascular procedures but only moderate in vascular procedures. CONCLUSIONS: Dose management software can be used to derive local DRLs for various IR procedures, taking into consideration different levels of complexity. Proposed local DRLs can contribute to obtaining detailed national DRLs as part of efforts to improve patients' radiation protection further.

Combined Use of a Patient Dose Monitoring System and a Real-Time Occupational Dose Monitoring System for Fluoroscopically Guided Interventions.

PURPOSE: To determine the effect on patient radiation exposure of the combined use of a patient dose monitoring system and real-time occupational dose monitoring during fluoroscopically guided interventions (FGIs). MATERIALS AND METHODS: Patient radiation exposure, in terms of the kerma area product (KAP; Gy ∙ cm(2)), was measured in period 1 with a patient dose monitoring system, and a real-time occupational dose monitoring system was additionally applied in period 2. Mean/median KAP in 19 different types of FGIs was analyzed in both periods for two experienced interventional radiologists combined as well as individually. Patient dose and occupational dose were correlated, applying Pearson and Spearman correlation coefficients. RESULTS: Although FGIs were similar in numbers and types over both periods, a substantial decrease was found for period 2 in total mean ± SD/median KAP for both operators together (period 1, 47 Gy ∙ cm(2) ± 67/41 Gy ∙ cm(2); period 2, 37 Gy ∙ cm(2) ± 69/34 Gy ∙ cm(2)) as well as for each individual operator (for all, P < .05). Overall, KAP declined considerably in 15 of 19 types of FGIs in period 2. Mean accumulated dose per intervention was 4.6 µSv, and mean dose rate was 0.24 mSv/h. There was a strong positive correlation between patient and occupational dose (r = 0.88). CONCLUSIONS: Combined use of a patient dose monitoring system and a real-time occupational dose monitoring system in FGIs significantly lessens patient and operator doses.

Improving Patient Safety: Implementing Dose Monitoring Software in Fluoroscopically Guided Interventions.

PURPOSE: To assess whether dose monitoring software can be successfully implemented in fluoroscopically guided interventions and to provide dose data based on levels of complexity. MATERIALS AND METHODS: After launching the software (DoseWatch; GE Healthcare Systems, Buc, France), data were collected for 6 months and analyzed by means of kerma-area product (KAP; Gy/cm(2)), cumulative air kerma (KA,R; Gy), and fluoroscopic time (minutes). Data analysis was executed by level of complexity as graded by the operators. Complexity grading was based on factors such as tortuosity and calcification of vessel, variant anatomy, and patient cooperation. RESULTS: The software successfully transferred dose data of 357 fluoroscopically guided procedures. KAP was 0.238-400 Gy/cm(2) with mean, median, and 75th percentile values of 46.0 Gy/cm(2), 163.2 Gy/cm(2), and 541.1 Gy/cm(2) (KA,R, 0.013-4.1 Gy; mean, median, 75th percentile, 0.48 Gy, 0.97 Gy, 3.98 Gy). Highest dose values were seen in transarterial chemoembolization (KAP mean, median, 75th percentile, 229.5 Gy/cm(2), 216.4 Gy/cm(2), 299.9 Gy/cm(2); KA,R mean, median, 75th percentile, 1.9 Gy, 1.2 Gy, 1.7 Gy). Analysis revealed that the level of complexity strongly correlated with KAP (r = 0.88; P < .001) whereas there was no direct correlation of KAP and fluoroscopy time. During the same intervention, KA,R and fluoroscopy time increased with level of complexity, but the correlation was not statistically significant. CONCLUSIONS: Implementation of dose monitoring software in fluoroscopically guided interventions can be successfully accomplished, and it facilitates data comparison.

Off-label use of thoracic aortic endovascular stent grafts to simplify difficult resections and procedures in general thoracic surgery.

OBJECTIVES: Tumour infiltration, or gross infectious involvement of the thoracic aortic wall, poses a significant intraoperative risk for fatal bleeding and therefore could compromise adequate resection or efficient surgical management of pleural infection in a considerable amount of cases. We present 3 successful cases of off-label thoracic aortic endografting to safeguard thoracic aortic wall integrity. METHODS: After all patients received thoracic stent grafts through femoral access into the descending aorta, the first patient underwent a resection of a locally advanced squamous cell carcinoma of the left inferior lobe cT4cN0-1cM0 after neoadjuvant chemoradiation, which had infiltrated the descending aortic wall. The second case was video-assisted thoracoscopic bilateral pleural decortication for empyema with aortic ulcers of the distal thoracic aorta in a patient with pancreatic intrathoracic fistula in a necrotizing pancreatitis. The third patient was operated for a locally advanced squamous cell carcinoma of the left inferior lobe initial stage cT4 cN1-2 cM0 after neoadjuvant chemoradiation, which had broad contact to the descending aorta at the level of thoracic vertebrae 7 and 8 on a circumference of circa 180°. Regional ethics committee approval according the Swiss Federal Human Research Act was obtained according to regulations. RESULTS: Preventive stent graft placement resulted in complication-free resection and significantly minimized the risk of fatal intraoperative bleeding. Patients were thus not exposed to complications associated with aortic cross-clamping, possible prosthetic replacement and extracorporeal circulation techniques. CONCLUSIONS: In carefully selected patient populations, the resection of locally advanced tumours or infectious processes involving the aortic wall can be facilitated by thoracic endovascular aortic repair prior to resection.