Radiation-induced Alopecia Following Stereotactic Radiosurgery for Calvarial or Scalp Tumors: A Single Institution Experience

Introduction: Alopecia is an undesirable side effect often experienced by patients undergoing stereotactic radiosurgery (SRS) to the calvarium or scalp. Although radiation-induced alopecia may affect patients’ quality of life, there are no published studies.

Methods: We retrospectively reviewed the clinical and radiological outcomes of patients with calvarial or scalp lesions who underwent CyberKnife SRS at our institute since January 2014. A total of 20 patients (median age 66 years, range: 17-80) with a total of 30 lesions (range: 1–6 per patient, 29 calvarial lesions, and 1 scalp lesion) underwent SRS. Eighteen patients had metastatic tumors, and two patients had meningioma invading the calvarium. SRS was delivered as a single fraction for 8 lesions, and hypofractionated for another 22 lesions (3 fractions for 12 lesions and 5 fractions for 10 lesions). The median follow-up was 8 months (range: 1-57).

Results: Among 30 lesions, 11 lesions showed temporary alopecia, and 19 lesions had no hair loss at all. There was no permanent alopecia. Lesions with temporary alopecia compared to the lesions with no alopecia presented statistically significant higher mean radiation dose per fraction for the lesion (13.6 vs. 9.2Gy), mean dose per fraction to the overlying scalp (7.4 vs 3.7Gy) and mean dose to the overlying scalp per scalp volume (2.1 vs 0.6Gy). Patients with a mean radiation dose per fraction to the overlying scalp higher than 6 Gy showed 81 times higher odds of having temporary alopecia than the patients with one lower than 6 Gy. None of the patients presented other adverse radiation effects, such as scalp irritation or necrosis. The 1-year local tumor control rate for lesions was 93.3%.

Conclusion : SRS is an effective and safe treatment modality for patients with calvarial or scalp mass. Hypofractionation can be helpful in preventing temporary alopecia for SRS treatment of the calvarial or scalp mass.