Patient dose estimation in CT guided biopsy procedures

• Main Author: Σιώμου, Ευαγγελία
• Other Authors: Siomou, Evangelia
• Language: English
• Published: 2023
• Subjects: Typical Diagnostic Reference Levels (DRLs); Computed tomography (CT); Διαγνωστικά επίπεδα αναφοράς (ΔΕΑ); Δόσεις ακτινοβολίας

This study reports the establishment of Typical Diagnostic Reference Levels (DRLs) values and the estimation of patients' doses during computed tomography (CT)- guided biopsy procedures. To determine the doses received by patients, effective dose (ED), entrance skin dose (ESD), and size-specific dose estimate (SSDE) were calculated using conversion factors derived from the literature. Research’s sample was taken from “Attikon” University Hospital. Five categories of CT-guided percutaneous needle biopsies were analyzed, including iliac bone biopsies (n=48), liver biopsies (n=57), lung biopsies (n=57), mediastinum biopsies (n=33), and para-aortic tissue biopsies (n=31). A total of 226 CT-guided biopsies performed from January 2017 to October 2022 by a single interventional radiologist were reviewed, and all technical and dosimetric parameters were retrospectively collected for analysis using DICOM data. Typical values of DRLs were calculated as the median values of the distributions. DRL values were proposed for the CTDIvol for the five categories of CT-guided biopsy procedures. DRLs in terms of CTDIvol were 9.7 mGy for Iliac bone, 8.9 mGy for liver, 8.8 mGy for lung, 7.9 mGy for mediastinal mass and 9 mGy for para-aortic lymph nodes biopsy procedures for helical mode acquisitions. For biopsy scans, DRL values were found to be 7.3 mGy, 7.7 mGy, 5.6 mGy, 5.6 mGy and 7.4 mGy respevtively. Typical DLRs were established as per the latest International Commission on Radiological Protection report 135 definition for five categories of CT-guided biopsy procedures without use of fluoroscopy. Helical scans across the entire anatomical region greatly affect radiation dose compared to biopsy acquisitions.