High-dose stereotactic radiosurgery for large brainstem metastasis and its recurrence treatment

Background. Breast cancer contributed to 11.8 % of all the oncological diseases detected in Russia in 2020 and to 21.7 % of tumors detected among women. The frequency of brain metastases is estimated at 13–32 %. It is known that HER2 positive and triple negative breast cancers metastasize to the brain more frequently.Aim. To present the case of stereotactic high‑dose irradiation for a large brainstem metastasis from HER2 positive breast cancer and re‑irradiation of the recurrence.Materials and methods. Analysis of the results of stereotactic irradiation for a large brainstem metastasis from HER2 positive breast cancer and re‑irradiation of the recurrence with a local control over five years was performed.Results. The local control after five years did not show any signs of tumor progression or post‑radiation necrosis. The patient’s Karnofsky Performance Status was estimated at 100 points.Conclusions. The case shows the necessity of highly conformal stereotactic dose delivery to the tumor, precise determination of tumor boundaries on high resolution thin slice magnetic resonance imaging, verification of recurrence using metabolic studies and hypofractionated dose delivery. It remains open whether and to what extent target therapy may contribute to local control.