ABSTRACT
Stereotactic radiosurgery (SRS) is an effective treatment for incompletely resected or recurrent pituitary adenomas characterized by high rates of local control and endocrinological remission. The SRS-associated morbidity is usually considered minimal, but could not be neglected. It is mainly related to new pituitary hormone deficit, and seemingly caused by un-intentional inclusion of the hypothalamus, pituitary stalk and gland in the high-dose irradiation area. We report long-term clinical outcomes of 30 pituitary adenoma patients who received SRS in our institution. Dose was generally prescribed to the 90% isodose line and ranged from 10 to 16 Gy (mean and median 14 Gy). Selection of prescription dose was based on a tumor location and proximity to adjacent radiation-sensitive structures and previous radiotherapy. The length of follow-up varied from 15 to 230 months (mean 102.6 months, median 90 months). Overall, in 28 patients (93%) control of tumor growth was observed during the followup. In 19 patients (63%) tumor size was considered stable after SRS, in 9 patients (30%) tumor reduced in size and in 2 patients (7%) tumor progression was observed. Among 26 patients with functioning pituitary adenomas 17 patients (65,4%) had normalization and 4 patients (15,3%) had improvement of endocrinological function. Persistent hypersecretion was observed in 5 patients (19,3%) with functioning pituitary adenomas. New hypopituitarism after SRS treatment was observed in 4 patients (13.3%). The median maximum dose to hypothalamus, pituitary stalk and pituitary gland was 2.33 Gy (range 0.78-6.22 Gy), 11.20 Gy (range 3.17-15.49 Gy) and 12.83 Gy (range 5.00-15.24 Gy), respectively. SRS allows to effectively control tumor growth in 90-100% of patients and in the great part of patients a relatively rapid endocrinological remission is observed. Doses to the structures of hypothalamic-pituitary axis might have influence on the development of radiation-induced hypopituitarism. Every effort should be made to spare these structures as much as possible.
ABSTRACT
PURPOSE: 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). METHODS AND MATERIAL: 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. RESULTS: 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). CONCLUSION: 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.