[Temporary localized alopecia following neuroradiological procedures: 18 cases]

The treatment of cerebral lesions using endovascular radiological procedures is becoming a standard of care. Radiation-induced alopecia, a type of acute radiodermatitis, is a frequent complication. Between 2009 and 2010, a number of patients reported hair loss after embolization of a cerebral arteriovenous malformation at the Neuroradiology Department of the Strasbourg University Hospital. We therefore retrospectively investigated 18 cases to better delineate the circumstances and the risk factors associated with radiation-induced alopecia.

We reviewed the records of 35 patients reporting hair loss among the 347 patients undergoing embolization of cerebral arteriovenous malformations between January 2008 and May 2010. Only patients with photographically documented complete circumscribed alopecia were included. Patients were examined and interviewed by a dermatologist and/or a radiologist at the time of hair loss and at a later point. The cumulative dose of radiation delivered to the skin in the 3 months preceding onset of alopecia, then over the entire period 2008-2010, was calculated. These doses included the diagnostic (angiography) and therapeutic (embolization) procedures.

Definite circumscribed alopecia was noted in 18 patients. Alopecia occurred between two and four weeks after embolization; it was complete and in no cases cicatricial. Complete recovery as attested by examination or photography was observed in 12 patients. The cumulative dose over the preceding three months was between 2.5 Gy and 12.3 Gy (mean: 5 Gy). The total cumulative dose since January 2008 was between 3.2 and 17 Gy (mean: 7 Gy).

We describe a series of 18 patients with radio-induced alopecia occurring after diagnostic and therapeutic procedures for cerebral arteriovenous malformations. This series is particularly interesting because it includes the largest patient sample reported to date with an uncommon large area of alopecia, and also because we were able to calculate the cumulative dose of radiation delivered to the skin. In addition, we underline the importance of the cumulative dose in interventional radiology since radio-induced alopecia probably results from the number of interventional procedures during a given time period. Moreover, analysis of these doses provided us with a new perspective on the radiobiology of the hair growth cycle. Indeed, whereas previously reported data considered alopecia as definitive where doses higher than 7 Gy were delivered, we noticed regrowth of hair with doses of up to 12 Gy.

These observations underline the specific findings of radiation-induced alopecia and underline the importance of the cumulative radiation dose delivered during the 3 months preceding alopecia.