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

Cardiac catheterization real-time dynamic radiation dose measurement to estimate lifetime attributable risk of cancer

Cardiac catheterization procedure is the gold standard to diagnose and treat cardiovascular disease. However, radiation safety and cancer risk remain major concerns. This study aimed to real-time dynamic radiation dose measurement to estimate lifetime attributable risk (LAR) of cancer incidence and mortality in operators. Coronary angiography (CA) with percutaneous coronary intervention (PCI), CA, and others (radiofrequency ablation, pacemaker and defibrillator implantation) procedures with different beam directions, were undertaken on x-ray angiography system. A real-time electronic personal dosimeter (EPD) system was used to measure the radiation dose of staff during all procedures. We followed the Biological Effects of Ionizing Radiation (BEIR) VII report to estimate the LAR of all cancer incidence and mortality. Primary operators received radiation dose in CA with PCI, CA, and others procedures were 59.33 ± 95.03 μSv, 39.81 ± 103.85 μSv, and 21.92 ± 37.04 μSv, respectively. As to the assistant operators were 30.03 ± 55.67 μSv, 14.67 ± 14.88 μSv, and 4 μSv, respectively. LAR of all cancer incidences for staffs aged from 18 to 65 are varied from 0.40% for males to 1.50% for females. LAR of all cancer mortality for staffs aged from 18 to 65 are varied from 0.22% for males to 0.83% for females. Our study provided an easy, real-time and dynamic radiation dose measurement to estimate LAR of cancer for staff during the cardiac catheterization procedures. The LAR for all cancer incidence is about twice that for cancer mortality. Although the radiation doses of staff are lower during each procedure, the increased years of service leads to greater radiation risk to the staff.

Neurointerventionalist and Patient Radiation Doses in Endovascular Treatment of Acute Ischemic Stroke

PURPOSE

To evaluate the patient and the neurointerventionalist radiation dose levels during endovascular treatment of acute ischemic stroke, and to analyze factors affecting doses.

MATERIALS AND METHODS

From October 2017 to January 2019, we prospectively collected patient radiation data and neurointerventionalist data from real-time dosimetry from all consecutive thrombectomies. Multivariate analysis was performed to analyze patient total dose area product (DAP) and neurointerventionalist dose variability in terms of clinical characteristics and the technical parameters of thrombectomies. Local dose reference levels (RL) were derived as the 75th percentile of the patient dose distributions.

RESULTS

A total of 179 patients were treated during the study period and included in this study. Local dose RL for thrombectomy was derived for total DAP to 34 Gy cm², cumulative air kerma of 242 mGy and fluoroscopy time of 12 min. The mean neurointerventionalist dose for thrombectomy was 7.7 ± 7.4 µSv. Height (P = 0.018), weight (P = 0.004), body mass index (P = 0.015), puncture to recanalisation (P < 0.001), fluoro time (P < 0.001), number of passes (P < 0.001), thrombolysis in cerebral infarction 2b/3 recanalisation (P = 0.034) and aspiration thrombectomy (P < 0.001) were independent factors affecting patient total DAP, whereas baseline National Institutes of Health Stroke Scale (P = 0.043), puncture to recanalisation (P = 0.003), fluoroscopy time (P = 0.009) and number of passes (P = 0.009) were factors affecting the neurointerventionalist dose.

CONCLUSION

New reference patient doses lower than those in previously published studies were defined. However, the operator's doses were higher than those in the only available study reporting on operator's dose during cerebral interventions.

Monitoring and Follow-Up of High Radiation Dose Cases in Interventional Radiology

RATIONALE AND OBJECTIVES

To assess the implementation of radiation dose monitoring software, create a process for clinical follow-up and documentation of high-dose cases, and quantify the number of patient reported radiation-induced tissue reactions in fluoroscopically guided interventional radiology (IR) and neuro-interventional radiology (NIR) procedures.

MATERIALS AND METHODS

Web-based radiation dose monitoring software was installed at our institution and a process to flag all procedures with reference point air kerma (K_a,r) > 5000 mGy was implemented. The entrance skin dose was estimated and formal reports generated, allowing for physician-initiated clinical follow-up. To evaluate our process, we reviewed all IR and NIR procedures performed at our hospital over a 1-year period. For all procedures with K_a,r > 5000 mGy, retrospective medical chart review was performed to evaluate for patient reported tissue reactions.

RESULTS

Three thousand five hundred eighty-two procedures were performed over the 1-year period. The software successfully transferred dose data on 3363 (93.9%) procedures. One thousand three hundred ninety-three (368 IR and 1025 NIR) procedures were further analyzed after excluding 2189 IR procedures with K_a,r < 2000 mGy. Ten of 368 (2.7%) IR and 52 of 1025 (5.1%) NIR procedures exceeded estimated skin doses of 5000 mGy. All 10 IR cases were abdominal/pelvic trauma angiograms with/without embolization; there were no reported tissue reactions. Of 52 NIR cases, 49 were interventions and 3 were diagnostic angiograms. Five of 49 (10.2%) NIR patients reported skin/hair injuries, all of which were temporary.

CONCLUSION

Software monitoring and documentation of radiation dose in interventional procedures can be successfully implemented. Radiation-induced tissue reactions are relatively uncommon.

A Phantom Menace to Medical Personnel During Endovascular Treatment of Cerebral Aneurysms: Real-Time Measurement of Radiation Exposure During Procedures

BACKGROUND

The number of endovascular treatment procedures performed for cerebral aneurysms has markedly increased. However, little is known about the annual effective radiation dose to medical staff in neurointervention fields. We performed a retrospective observational study to investigate the real-time radiation dose to surgeons, nurses, anesthesiologists, and radiologic technologists during endovascular treatment of intracranial aneurysms.

METHODS

We measured the real-time radiation doses for 2 weeks using standard and reinforced protection, during which 28 procedures were performed, including 23 coil embolizations for unruptured intracranial aneurysms. Four procedures were excluded because of an inadequately equipped sensor, which resulted in inappropriate data collection. The procedure time was defined from intubation to extubation. Five RaySafe i2 detectors were installed at the chest level of the operator, attending nurse, radiologic technologist, and anesthesiologist and just inside the front door of the hybrid operating room.

RESULTS

The median doses per session with standard protection to the operator, attending nurse, anesthesiologist, and radiologic technologist were 11.16, 2.60, 4.76, and 1.93 μSv, respectively. The dose to the operator, attending nurse, and anesthesiologist had decreased to 6.63, 0.39, and 1.52 μSv under reinforced protection, respectively. However, the session dose for the radiologic technologist had increased to 3.12 μSv.

CONCLUSIONS

We confirmed the differences in the amount of radiation exposure for different roles. An additional lead screen, which provided more effective protection on the operator side, was proved effective for attenuating radiation exposure during endovascular treatment. All personnel involved in the hybrid operating room were exposed to acceptable effective doses.

Personalized Feedback on Staff Dose in Fluoroscopy-Guided Interventions: A New Era in Radiation Dose Monitoring

PURPOSE

Radiation safety and protection are a key component of fluoroscopy-guided interventions. We hypothesize that providing weekly personal dose feedback will increase radiation awareness and ultimately will lead to optimized behavior. Therefore, we designed and implemented a personalized feedback of procedure and personal doses for medical staff involved in fluoroscopy-guided interventions.

MATERIALS AND METHODS

Medical staff (physicians and technicians, n = 27) involved in fluoroscopy-guided interventions were equipped with electronic personal dose meters (PDMs). Procedure dose data including the dose area product and effective doses from PDMs were prospectively monitored for each consecutive procedure over an 8-month period (n = 1082). A personalized feedback form was designed displaying for each staff individually the personal dose per procedure, as well as relative and cumulative doses. This study consisted of two phases: (1) 1-5th months: Staff did not receive feedback (n = 701) and (2) 6-8th months: Staff received weekly individual dose feedback (n = 381). An anonymous evaluation was performed on the feedback and occupational dose.

RESULTS

Personalized feedback was scored valuable by 76% of the staff and increased radiation dose awareness for 71%. 57 and 52% reported an increased feeling of occupational safety and changing their behavior because of personalized feedback, respectively. For technicians, the normalized dose was significantly lower in the feedback phase compared to the prefeedback phase: [median (IQR) normalized dose (phase 1) 0.12 (0.04-0.50) µSv/Gy cm2 versus (phase 2) 0.08 (0.02-0.24) µSv/Gy cm2, p = 0.002].

CONCLUSION

Personalized dose feedback increases radiation awareness and safety and can be provided to staff involved in fluoroscopy-guided interventions.

Radiation Exposure during Neurointerventional Procedures in Modern Biplane Angiographic Systems: A Single-Site Experience

Background and Purpose

Per the ALARA principle, reducing the dose delivered to both patients and staff must be a priority for endovascular therapists, who should monitor their own practice. We evaluated patient exposure to radiation during common neurointerventions performed with a recent flat-panel detector angiographic system and compared our results with those of recently published studies.

Methods

All consecutive patients who underwent a diagnostic cerebral angiography or intervention on 2 modern flat-panel detector angiographic biplane systems (Innova IGS 630, GE Healthcare, Chalfont St Giles, UK) from February to November 2015 were retrospectively analyzed. Dose-area product (DAP), cumulative air kerma (CAK) per plane, fluoroscopy time (FT), and total number of digital subtraction angiography (DSA) frames were collected, reported as median (interquartile range), and compared with the previously published literature.

Results

A total of 755 consecutive cases were assessed in our institution during the study period, including 398 diagnostic cerebral angiographies and 357 interventions. The DAP (Gy × cm²), fontal and lateral CAK (Gy), FT (min), and total number of DSA frames were as follows: 43 (33-60), 0.26 (0.19-0.33), 0.09 (0.07-0.13), 5.6 (4.2-7.5), and 245 (193-314) for diagnostic cerebral angiographies, and 66 (41-110), 0.46 (0.25-0.80), 0.18 (0.10-0.30), 18.3 (9.1-30.2), and 281 (184-427) for interventions.

Conclusion

Our diagnostic cerebral angiography group had a lower median and was in the 75th percentile of DAP and FT when compared with the published literature. For interventions, both DAP and number of DSA frames were significantly lower than the values reported in the literature, despite a higher FT. Subgroup analysis by procedure type also revealed a lower or comparable DAP.

The use of intravenous tPA for the treatment of severe frostbite

OBJECTIVE

tPA and anticoagulation for treatment of severe frostbite have been reported suggesting differences in imaging techniques, route of tPA administration and management of patients after tPA infusion. This is a report of our results following a protocol of Tc-99m scanning, intravenous tPA administration, followed by either systemic anticoagulation or antiplatelet therapy.

METHODS

Patients admitted to our burn center between February 13, 2015 and February 13, 2016 for frostbite who met inclusion criteria were treated with Tc-99m scan and intravenous tPA followed by systemic anticoagulation or antiplatelet therapy. Inclusion criteria included rewarming had not started more than 24h prior to the scan and no contraindications to the use of tPA.

RESULTS

Fifteen patients met inclusion criteria and 12 were treated according to the protocol. Nine received scans with 2 showing normal perfusion. Seven displayed perfusion defects and received intravenous tPA. Five recovered fully after tPA. Two who showed improved but abnormal scans after tPA experienced bleeding complications necessitating stopping heparin/Coumadin. Those two went on to partial amputation of digits.

CONCLUSION

The use of intra-arterial or intravenous tPA along with angiography or Tc-99m scanning followed by systemic anticoagulation or antiplatelet therapy may be beneficial to patients suffering frostbite.