Authors (including presenting author) :
Li PM(1), Chen HS(1), Ng TM(2), Lam TP(2), Leung PS(1), Tsui PCB(1), Lun KS(1)
Affiliation :
(1) Department of Paediatrics and Adolescent Medicine (Cardiology), Hong Kong Children’s Hospital (2) Department of Radiology, Hong Kong Children’s Hospital
Introduction :
Detrimental effects of ionizing radiation exposure during cardiac catheterization are always of concern to paediatric patients with congenital heart diseases as they may require long and repetitive procedures. In Dec 2017, first phase of radiation reduction exercise based on the principle of “ALARA” (as low as reasonably achievable) was initiated in the Paediatric Cardiac Catheterization Laboratory (PCCL) at Queen Mary’s Hospital (QMH), which mainly involving reduction of frame rate. Since translocation of paediatric cardiology service to Hong Kong Children’s Hospital (HKCH) in Oct 2020, the second phase of radiation reduction exercise has commenced at our Hybrid Cardiac Catheterization Laboratory (HCL). Under this phase, based on the "ALARA" principle, measures including further frame rate and dose reduction, removal of anti-scatter grid with air-gap technique (AGT) for patients with <20kg of body weight were taken in practice.
Objectives :
To assess the effectiveness of radiation dose reduction in the second phase of radiation reduction exercise.
Methodology :
Subjects were patients aged <18 years old in the interventional procedures of (1) patent ductus arteriosus (PDA) device closure and (2) atrial septal defect (ASD) device closure in QMH PCCL (2017-2019) and HKCH HCL (2020-2022). Outcomes were measured by comparisons of dose area product (DAP) between two phases.
Result & Outcome :
All censored procedures were successfully performed. Total 33 and 45 patients had undergone PDA device closure in QMH PCCL (2017-2019) and HKCH HCL (2020-2022) respectively. The mean of DAP in PDA device closure was decreased from 7.62 ± 5.42 Gycm² in PCCL to 1.92 ± 1.90 Gycm² in HCL (p<0.001). In the procedure of ASD device closure, there were 31 patients in PCCL and 46 patients in HCL recruited. The mean of DAP was greatly reduced from 22.34 ± 19.10 Gycm² in PCCL to 4.66 ± 10.41 Gycm² in HCL (p<0.001). The image quality had not been downgraded and there was no significant difference in procedural time after the reduction of frame rate and use of AGT. Conclusion: The enact of the radiation reduction exercise with the principle of “ALARA” and air-gap technique markedly reduced the radiation exposure in the procedures of PDA and ASD device closure on patients aged <18 years old.
