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 LID and I I 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. (C) RSNA, 2003.