International Atomic Energy Agency Radiation risks in paedriatic

International Atomic Energy Agency Radiation risks in paedriatic interventional cardiology L 10 Lecture 10: Radiation risks in paediatric interventional cardiology

Educational Objective 1. Unique considerations in paediatric patients having bearing on patient dose 2. How can dose be managed in paediatric patients Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 2

Unique Considerations for Radiation Exposure in Children • • • There are two unique considerations in children: • • Children are considerably more sensitive to radiation than adults Children also have a longer life expectancy, resulting in a larger window of opportunity for expressing radiation damage. As an example, compared with a 40 -year old, the same radiation dose given to a neonate is several times more likely to produce a cancer over the child's lifetime. Great attention to not optimised procedures in CT examinations: • • the same exposure parameters used for a child an adult will result in larger doses to the child there is no need for these larger doses to children. Currently, adjustments are not frequently made in the exposure parameters Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 3

Unique Considerations for Radiation Exposure in Children CT as a Diagnostic Tool It will address the following issues: • CT as a diagnostic tool • Unique considerations for radiation • Radiation risks from CT in children: a public health issue • Immediate strategies to minimize CT radiation exposure to children Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 4

Risk probability for stochastic effects as a function of age at exposure Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 5

Epidemiology evidences (I) Ionizing radiation and cancer risk: evidence from epidemiology Ron E. Radiat Res. 1998 Nov; 150(5 Suppl): S 30 -41 • …. . For all solid cancers combined, cancers of the thyroid, breast and lung, and leukemia, risk estimates are fairly precise, and associations have been found at relatively low doses (<0. 2 Gy). • Associations between radiation and cancers of the salivary glands, stomach, colon, bladder, ovary, central nervous system and skin have also been reported, but the relationships are not as well quantified. …. . Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 6

Epidemiology evidences (II) Radiation-induced skin cancer in humans Shore RE. Med Pediatr Oncol. 2001 May; 36(5): 549 -54 • . . . The Japanese atomic bomb study indicates that doses of radiation under about 1 Gy confer less risk per unit dose than higher doses do. • … skin cancer risk is greater from radiation exposure at young ages than at older ages…. . . • … available evidence indicates that the excess risk of skin cancer lasts for 45 years or more following irradiation … Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 7

Epidemiology evidences (III) • Cancer risks from medical radiation Ron E. Health Phys. 2003 Jul; 85(1): 47 -59 • Because doses from diagnostic examinations typically are low, they are difficult to study using epidemiological methods, unless multiple examinations are performed… • An excess risk of breast cancer has been reported among women: • with tuberculosis who had multiple chest fluoroscopies • scoliosis patients who had frequent diagnostic x rays during late childhood and adolescence. Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 8

Frequency of cardiac intervention in pediatrics Spanish Registry on Cardiac Catheterization and Coronary Interventions. (1990 -2002)] Data from 101 centers … 6 carried out only pediatric procedures. … a total increase of 5. 1% in comparison to 2001. • The population-adjusted rate: • 2, 053 coronary angiograms per million inhabitants • 850 coronary interventions per million inhabitants • Coronary interventions increased by 11% in comparison to • • • 2001 Stenting accounted for 91. 7% of all procedures Direct stenting was done in 13 768 procedures (43. 2%). Multivessel percutaneous in 9, 830 patients (28%), and ad hoc interventions in 26, 341 patients (76%). … and the slight increase in pediatric interventions (3. 7%). Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 9

Indications for interventions in pediatric cardiology • • Interventional catheterization in pediatric cardiology: tools and indications Boudjemline Y. , Arch Pediatr. 2004 Mar; 11(3): 276 -84. During the last decade, a remarkable number of transcatheter methods were developed: • • • balloon dilatation to treat vascular or valvular obstructive lesions, intravascular stents to manage obstructive lesions that cannot be satisfactorily balloon-dilated, transcatheter closure of atrial septal defects, patent ductus arteriosus, and ventricular septal defect. More recently, pulmonary valve replacement has become possible through a percutaneous technique Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 10

Indications for interventions in pediatric cardiology Future of interventional cardiology in pediatrics Levi DS, Alejos JC, Moore JW. Curr Opin Cardiol. 2003 Mar; 18(2): 79 -90. • A trend toward use of less invasive, non-surgical approaches to the treatment of congenital heart disease has developed • Additionally, fetal catheter-based interventions are being developed for the treatment of severe congenital heart disease in utero • Trend toward catheter-mediated treatment is certain to continue, care must be taken to regulate safely the introduction of novel techniques and devices into clinical use Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 11

Radiation Exposure to Children during various interventions (I) • • • Procedure No. patients Fluoroscopy time (min) Cine time (sec) Total cumulative skin dose (m. Gy) PDA 8 10. 1 ± 1. 8 11. 5± 1. 8 97± 25 PBV 5 19. 3 ± 2. 3 10. 9± 2. 3 86± 32 Amplatzer 14 23. 5 ± 2. 1 19. 9± 3. 3 102± 34 DC 12 13. 2 ± 1. 5 18. 7± 1. 5 108± 21 DC=diagnostic catheterization, PDA=Coil occlusion of the patent ductus arteriosus, PBV=pulmonary balloon valvuloplasty Coil occlusion of the patent ductus arteriosus (PDA) as well as other more complex pediatric interventions has raised concern regarding radiation exposure No correlation between fluoroscopy time and measured entrance dose Strongest correlation cumulative dose vs. patient weight and BSA J. Donald Moore, David Shim, John Sweet, Kristopher L. Arheart and Robert H. Beekman III, Catheterization and Cardiovascular Interventions 47: 449– 454 (1999) David Shim, Thomas R. Kimball, Erik C. Michelfelder, Lisa Koons, RN and Robert H. Beekman, Catheterization and Cardiovascular Interventions 51: 451– 454 (2000) Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 12

Radiation Exposure to Children during various interventions (II) • Cumulative skin dose is well correlated with patient size and not with fluoroscopy time Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 13

Radiation Exposure to Children during various interventions (III) Comparison of surface entrance doses of radiation. A: Present study (Amplatzer atrial septal defect closure). B: Moore et al. [6] (patent ductus coil occlusion). C: Moore et al. [6] (pulmonary valvuloplasty). D: Wu et al. [8] (pulmonary valvuloplasty). E: Park et al. [10] (arhythmia ablation). F: Rosenthal et al. [11] (arhythmia ablation). Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 14

Occupational exposure in pediatric interventions • Although pediatric cardiologists have • been performing cardiac catheterizations in infants and children for over 30 years, data regarding their occupational exposure are sparse Radiation exposure during arrhythmia ablation procedures in children, as measured by fluoroscopy duration, has been shown to be comparable to adults Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 15

Summary • Increased radiation risks for pediatric patients • Evidence of increased number of pediatric • • • interventional procedures Radiation doses can be high Very few dosimetric studies Radiological technique must be optimised and tailored to small body sizes: • Re-consider the need of antiscatter grid (doserate x 2) • Avoid electronic magnifications • Use collimations (reduce imparted energy, organ and • effective dose) Image intensifier close to patient skin Radiation Protection in Cardiology Lecture 10: Radiation risks in paediatric interventional cardiology 16