Can Patients With Neonatal Digestive Diseases Be Protected From Unnecessary Radiation?
The authors chose a specific group of patients with EA who could be considered one of the highest risk groups for neonatal irradiation. Indeed, due to the complexity of their surgical repair and the high prevalence of complications (ie, esophageal stricture, leak, recurrent fistula, tracheomalacia, gastroesophageal reflux) children with EA undergo substantial numbers of imaging studies for diagnostic and therapeutic procedures (2). The authors show that these patients are exposed to a significant increase in irradiation and conclude that this leads to a 130-fold increase in their risk of developing cancer later in life. This is a clear warning, but to be definitive a much longer follow-up is needed.
Controversial data on this topic have been published previously. In their article, Puch-Kapst et al (3) showed that neonatal intensive care unit-treated very-low-birth-weight infants had lower radiation exposure compared to annual natural background radiation levels. Baird et al (4) showed that neonates with necrotizing enterocolitis are exposed to significant amounts of radiation, that this is attributable to disease surveillance, and that their median cumulative lifetime mortality risk from cancer is therefore increased by an average of 4.3. Sources of radiation include conventional x-ray (eg, plain radiography, opacification) and computed tomography (CT) scan. Although not assessed in the study by Yousef and Baird, the level of pediatric radiation exposure from CT scans also remains a matter of debate (5,6).
As acknowledged by the authors, there are limitations to their study (as there are with most of those previously published). The first limitation is the study's retrospective nature, which led them to include excessive radiation exposure due to use of older equipment that is greatly reduced by modern equipment. The second limitation is the relatively short duration of follow-up and lack of data confirming the long-term health consequences of irradiation. There is currently no evidence for increased cancer risk in the EA population, aside from concern about esophageal cancer (of which there have been 8 cases reported in patients with EA); furthermore, this is not a classic cancer due to irradiation (ie, it is predominantly brain cancer and leukemia), but is instead caused by severe gastroesophageal reflux disease, esophageal dysmotility or lesion (2).
Indeed, it is currently impossible to predict whether an individual will experience the consequences of radiation (6). Another problem is related to the calculation of risk. Authors usually choose previously published radiation data or data supplied by the International Commission on Radiologic Protection as references for studies, because it has been shown that estimating radiation exposure and cancer risk may be inexact (6).