A Patient Dose-Reduction Technique for Neuroendovascular Image-Guided Interventions: Image-Quality Comparison Study

Practical dosimetry procedure of air kerma for kilovoltage X-ray imaging in radiation oncology using a 0.6-cc cylindrical ionization chamber with a cobalt absorbed dose-to-water calibration coefficient

In this study, we implemented a practical dosimetry procedure of air kerma for kilovoltage X-ray beams using a 0.6-cc cylindrical ionization chamber, and validated the procedure with the accuracy of the measurements using the 0.6-cc chamber compared to the measurements using a 6-cc chamber and a semiconductor device. In addition, the kerma area products (KAPs) were compared with the dose reference levels of radiology. A modified air kerma formalism using a 0.6-cc cylindrical ionization chamber air kerma formalism with a cobalt absorbed dose-to-water calibration coefficient was implemented. Validation of the formalism showed good agreement between the 0.6-cc chamber and the 6-cc chamber (< 5%), and between the 0.6-cc chamber and the semiconductor device (< 2%) in the 60-120 kV range. The KAPs for four RO machines had difference factors of 0.04-15.4 and 0.01-4.1 from their median and maximum dose reference levels in radiology, respectively.

How should radiation exposure be handled in fluoroscopy-guided endoscopic procedures in the field of gastroenterology?

Fluoroscopy-guided endoscopic procedures (FGEPs) are rapidly gaining popularity in the field of gastroenterology. Radiation is a well-known health hazard. Gastroenterologists who perform FGEPs are required to protect themselves, patients, as well as nurses and radiologists engaged in examinations from radiation exposure. To achieve this, all gastroenterologists must first understand and adhere to the International Commission on Radiological Protection Publication. In particular, it is necessary to understand the three principles of radiation protection (Justification, Optimization, and Dose Limits), the As Low As Reasonably Achievable principle, and the Diagnostic Reference Levels (DRLs) according to them. This review will mainly explain the three principles of radiation exposure protection, DRLs, and occupational radiological protection in interventional procedures while introducing related findings. Gastroenterologists must gain knowledge of radiation exposure protection and keep it updated.

Establishment of national diagnostic reference levels for percutaneous coronary interventions (PCIs) in Thailand

PURPOSE

To establish national diagnostic reference levels (DRLs) for percutaneous coronary intervention (PCI) in Thailand for lesions of different complexity.

METHODS

Radiation dose quantity as kerma-area-product (KAP) and cumulative air-kerma at reference point (CAK) from 76 catheterization labs in 38 hospitals in PCI registry of Thailand was transferred online to central data management. Sixteen months data (May 2018 to August 2019) was analyzed. We also investigated role of different factors that influence radiation dose the most.

RESULTS

Analysis of 22,737 PCIs resulted in national DRLs for PCI of 91.3 Gy.cm² (KAP) and 1360 mGy (CAK). The NDRLs for KAP for type C, B2, B1 and A lesions were 106.8, 82.6, 67.9, and 45.3 Gy.cm² respectively and for CAK, 1705, 1247, 962, and 790 mGy respectively. Thus, as compared to lesion A, lesion C had more than double the dose and B2 had nearly 1.6 times and B1 had 1.2 times CAK. Our DRL values are lower than other Asian countries like Japan and Korea and are in the middle range of Western countries. University hospital had significantly higher dose than private or public hospital possibly because of higher load of complex procedures in university hospitals and trainees performing the procedures. Transradial approach showed lower doses than transfemoral approach.

CONCLUSIONS

This large multi-centric study established DRLs for PCIs which can act as reference for future studies. A hallmark of our study is establishment of reference levels for coronary lesions classified as per ACC/AHA and thus for different complexities.

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.