Carotid atherosclerotic disease following childhood scalp irradiation

During the first half of the 20th century, scalp irradiation was a standard treatment for children suffering from Tinea Capitis. These children are now more than 50 years old, reaching the age when manifestations of atherosclerosis are common. We investigated the possible association between childhood low dose scalp irradiation and development of carotid atherosclerosis in adulthood.

The study included 145 individuals treated by irradiation in their childhood, and 150 matched control subjects with no history of irradiation. The occurrence of stroke was disregarded during the inclusion. B-mode ultrasound imaging and US Doppler were used to measure carotid, femoral (distant from the radiated area) and intima media thickness (IMT). Blood lipids and homocysteine were also evaluated.

No significant differences in the baseline patients' characteristics were observed. There were no differences in incidence of femoral IMT or prevalence of femoral stenosis between the groups. However, in the carotid of the irradiated group, a significantly elevated IMT and significantly increased prevalence of carotid stenosis were observed (p<0.001). In the irradiated group, 30.3% and 39.3% had stenosis in the right or left carotid arteries, compared to 12.7% and 16% in controls(p<0.001), adjusted OR=5.36[CI:2.78-10.33]. More participants in the irradiated group had experienced ischemic stroke: 13 patients (9%) from the irradiated group vs. 3 patients(2%) from the non-exposed group, p=0.01.

Childhood scalp irradiation is a significant and thus far underestimated risk factor for adult carotid atherosclerosis disease. Physicians should be aware of the existence of such high risk populations.