30 M. Alvarez et al.: Radioprotection 2025, 60( 1), 28 – 36
limb arteriography; Head and / or neck angiography; Coronary angiography( diagnostic); Pelvic vein embolization; Thoracic angiography of pulmonary artery or aorta; Abdominal angiography or aortography and Transjugular intrahepatic portosystemic shunt placement.
The LDRLs were established at the third quartile( Q3) for the values of K, KAP, T, and N. The median was determined to showcase the Typical Dose Values, in accordance with the guidelines recommended in ICRP 135. Even though dosimetric data typically do not follow a normal distribution, mean values were also computed due to their frequent reference in ICRP 135. For the statistical analysis of each variable, the Python library Numpy was employed for its data analysis capabilities.
2.3 Determination of effective dose and conversion factor
Fig. 2. Flowchart representing the operation of the software for extracting quantities from the reports provided by the Artis Zee Ceiling equipment.( I) The first step is to determine the evaluation period for the procedures.( II) The reports provided by the equipment are extracted, added to the program’ s image base and additional information is removed from the DICOM header associated with the procedure.( III) The Pytesseract library, in Python, is used to transcribe the data into the report. Information provided in the DICOM header, such as procedure name or patient ID, was extracted.( IV) The information extracted is reviewed by the authors.( V) The verified data is added to the database.
2.1 Inclusion and exclusion criteria
When patients underwent multiple procedures on the same day, identified by the same record in the PACS system( such as two arteriography procedures on the lower limbs for the same patient), the dosimetric data from these procedures were aggregated and considered as a single procedure. During the validation phase, the OCR-generated data were scrutinized, and any entries with data inconsistencies were eliminated, resulting in 8 exclusions. Consequently, 1334 entries were deemed valid and successfully extracted by the algorithm, achieving a data extraction accuracy rate of 95 %.
2.2 Data analysis
Procedures were grouped according to the most relevant classification as: Coronary percutaneous transluminal angioplasty, stent placement, or radiofrequency ablation; Lower
With the LDRLs obtained, the PCXMC 2.0 software was used to calculate the Effective Dose( E) in patients, considering the weighting factors of the ICRP103 available in the Monte Carlo software. This software allows for detailed customization of projection angles, additional filtration, and focusdetector distance. We used the PCXMC Rotation feature to simulate the various projections and accurately calculate the Effective Dose. Monte Carlo beam simulation and projections were matched with the protocol used in the routine and are specified in Table 1, including C-arm projections for each procedure type.
The kV values and additional filtration were determined using the median values from our clinical data. The standard dose and the most used Field of View( FOV) were selected for the simulations. These scenarios were established by analysing the reports provided by the equipment, which detailed the kV values and the percentage contributions of each projection to the total KAP. These projections include adult cardiac catheterization, bile drainage, catheter implant and lower limb arteriography.
All equipment underwent rigorous quality control procedures in accordance with Brazilian regulatory standards for fluoroscopy protocols. The tolerance for the percentage difference between displayed values and measured values for Air Kerma and KAP is 20 % This ensures the accuracy and reliability of the dose measurements used in our study( Ministério da Saude, 2021).
In each simulation, the median values for kVp and added filtration were utilized. The most frequently used projection and field of view( FOV) settings were also applied. The stories of one million photons were applied, focus-detector distance of 120 centimetres, focus-skin distance of 80 cm. The simulated patient is 178.2 cm tall, 73.2 kg, and 30 years old. The ratio between the E values and the 3rd quartile value for K were used to calculate the conversion factor( Cf), as described by equation( 1): cf ¼ E K; ð1Þ
where E is in mSv, K is measured in mGy, and Cf in Sv / Gy. Subsequently, the results were compared with previous studies carried out for dose surveys in interventional radiology procedures.