Radiosurgery and whole brain therapy in the treatment of brainstem metastases

The incidence of brainstem metastasis (BSM) accounts for 1-3% of brain metastases (BM). They are often associated with multiple BM and produce significant neurological symptoms. We retrospectively analyse the results of treatment with stereotactic radiosurgery (SRS).

We included the medical records of 28 patients aged 52.86+/-11.29 years; 17 (60.7%) were women. The most frequent primary tumours were breast (n=11), lung (n=9) and melanoma (n=4). A total of 30 BSM were treated with radiosurgery (SRS) with a linear accelerator (Linac Scalpel, University of Florida). The 3D planning was with image fusion.

The mean time from the diagnosis of the primary tumour to the BM was 3+/-3.35 years; 5 cases were diagnosed simultaneously. Twenty-seven patients (96.4%) received whole brain radiotherapy, 19 before SRS and 8 after. The most usual dose was 30 Gy. Three patients underwent another SRS for other BM. The medium volume of BSM was 1.86+/-2.31 cc. The mean prescribed dose was 1114.33+/-315.6 cGy. The tumour volume did not change significantly with SRS but there was neurological improvement in 13 patients (41.9%). Twenty-four patients (85.7%) died, 22 (78.5%) due to the primary tumour: 12 cases (42.8%) due to progression of BM, 1 case due to progression of BSM and 10 due to local tumour progression or extra-cerebral metastases. Mean survival from diagnosis of BM was 22.8+/-32.4 months and from SRS of BSM, 16.8+/-31.56 months (1 month to 13.54 years).

The combined treatment of SRS and whole brain radiotherapy treatment is effective in the control of BSM (only one patient died due to progression of BSM), improving the neurological symptoms in 41.9% of patients; therefore an early diagnosis and treatment is important. Many patients die due to causes other than the BSM.