Asymptomatic radiation-induced telangiectasia in children after cranial irradiation: frequency, latency, and dose relation.

PURPOSE

To determine the frequency, dose relation, and latency of radiation-induced telangiectasias in children after cranial irradiation.

MATERIALS AND METHODS

The authors identified 90 children who had undergone cranial irradiation between 1981 and 2001 and undergone magnetic resonance (MR) imaging with follow-up for at least 6 months. Patients were assigned to low-dose (LD) and high-dose (HD) groups. All 24 children in the LD group received a radiation dose of 18.0 or 19.8 Gy. The 66 patients in the HD group received a dose of 32.0 Gy or greater. Telangiectasias were defined as small low-signal-intensity foci on intermediate- or T2-weighted MR images. For the patients who underwent serial MR imaging, the first depicted appearance of each telangiectatic lesion was recorded. Statistical analyses were performed.

RESULTS

Telangiectasias in at least one area were observed in 18 (20%) patients. The frequency of telangiectasia was 13% (three of 24 patients) in the LD group as compared with 23% (15 of 66 patients) in the HD group; this difference was not significant (P =.22, Fisher exact test). In 12 patients (one from LD and 11 from HD group) who underwent serial MR imaging follow-up for up to 10 years (mean, 8.1 years), a total of 31 lesions were detected. Twelve (39%) of these lesions were detected by the 3rd year, and 21 (68%) were evident by the 5th year. Six (50%) of the 12 patients who underwent serial MR imaging had telangiectatic foci after 5 years.

CONCLUSION

Radiation-induced telangiectasia appears to occur in at least 20% of children who undergo cranial irradiation. In this small series, higher radiation dose was not significantly associated with higher frequency of telangiectasia, although there was a trend in this direction.