Cumulative effective and organ dose estimation and cancer risk assessment in pediatric interventional cardiology patients

Background: Pediatric patients with congenital or acquired heart diseases often undergo repeated interventional cardiology (IC) procedures and multimodal diagnostic examinations throughout their clinical journey. Given the higher radiosensitivity of pediatric tissues and the longer life expectancy, the accurate assessment of the cumulative dosimetric burden and the estimation of the resulting stochastic risk are of fundamental importance in radiation protection. Materials and Methods: A retrospective study was conducted on a cohort of pediatric patients (n = 163) who underwent at least two interventional cardiology procedures at the Padua University Hospital between September 2018 and April 2024. The analysis integrated dosimetric contributions from IC procedures, conventional radiology (RX), Computed Tomography (CT), and Nuclear Medicine (NM). Dosimetric reconstruction was performed using the National Cancer Institute (NCI) software suite: NCIRF for fluoroscopic and radiographic procedures, NCICT for CT examinations, and NCINM for nuclear medicine procedures. The Cumulative Effective Dose (CED) and Cumulative Organ Doses (COD) were calculated for each patient. Subsequently, the radiation-induced cancer risk (Lifetime Attributable Risk, LAR) was estimated by applying and comparing the BEIR VII and ICRP 103 risk models. Results: The study population consisted of 163 patients (54% male, 46% female) with a median age at the first procedure of 3.5 years (IQR: 0.8–10.6 years). The estimated median CED for the cohort was 5.16 mSv (IQR: 1.9–12.4 mSv). Modality-specific analysis identified CT as the dominant contributor to the total dose burden. Eight patients (4.9%) exceeded a CED of 50 mSv, with two surpassing 100 mSv. Organ dose analysis revealed that the lungs and heart wall were the most exposed tissues. Regarding risk assessment, both models showed a strong correlation (R2 > 0.95), although BEIR VII estimates were systematically higher. A limited fraction of the cohort showed a LAR greater than 1%. Conclusions: This study demonstrates that cumulative exposure in complex pediatric cardiac patients can reach significant levels, primarily driven by diagnostic CT imaging rather than fluoroscopy alone. These results underscore the insufficiency of single-procedure assessments and highlight the necessity for personalized optimization strategies and integrated dosimetric monitoring in long-term follow-up.