Doses from ionising radiation in paediatric cardiac catheterisations in Norway 1975-2021.

Paediatric patients with congenital heart disease often undergo cardiac catheterisation procedures and are exposed to considerable ionising radiation early in life. This study aimed to develop a method for estimating the dose area product (PKA) from paediatric cardiac catheterisation procedures (1975-1989) at a national centre for paediatric cardiology and to evaluate trends inPKAand exposure parameters until 2021. Data from 2200 catheterisation procedures on 1685 patients (1975-1989) and 4184 procedures on 2139 patients (2000-2021) under 18 years of age were retrospectively collected.PKAvalues were missing for 1975-1989 but available from 2000 onward. The missingPKAwas estimated from air kerma and beam area, based on exposure records and input from clinicians working at that time.PKAtrends were analysed over time and age. There was a 71% reduction in medianPKAfrom the period 1975-1989 (median 6.63 Gy cm2) to 2011-2021 (1.91 Gy cm2). ThePKAincreases significantly (p= 0.0001) with patient age, which was associated with body weight. Approximately 80% of the totalPKAwas from cine acquisition in 1975-1989, while 20% was from fluoroscopy. ThePKAestimate during 1975-1989 was considerably impacted by the assumptions of missing parameters such as tube filtration, focus-to-heart distance, beam area, and number of cine series. The decreasing trend inPKAvalues was attributed to advancements in both technologies and clinical practices. The high contribution of cine acquisition to the total dose during 1975-1989 was due to factors such as a high frame rate, multiple acquisitions, and high tube current. The estimatedPKAvalues for the period 1975-1989 are of importance for the dose reconstruction and risk assessments in the EU epidemiology project Health Effects of Cardiac Fluoroscopy and Modern Radiotherapy in Pediatrics(HARMONIC).