Stereotaxic Radiotherapy and Radiosurgery of Brain Metastases

A.V. Golanov, V.V. Strukalev, T.M. Kotelnikova, I.N. Pronin, M.B. Dolgushin, G.E. Gorlachev, S.R. Ilyalov, A.A. Podoprigora, G.L. Kobyakov, V.A. Loshakov

Burdenko Research Institute of Neurosurgery, Moscow, Russia

 

Different types of stereotaxic radiotherapy (SRT) and radiosurgery (SRS) are standard modern methods of treatment of brain metastases. There were 184 cases, aged 26-76, who were treated at the Institute of Neurosurgery in 2005-2008. The number of procedure was 213 (without taking into account those, carried out with the Gamma-Knife apparatus). Primus and Novalis linear accelerators and the Teragam gamma-apparatus were used. Radiosurgery and radiotherapy were carried out in 63 and 152 cases (61- irradiation of the whole brain, 91 stereotaxic conformal radiotherapy), respectively. Karnofsky index of 70 and more was observed in 172 cases. A source of metastasis was as follows: a mammary gland 64 cases, lungs 40, melanoma 20, a gastrointenstinal tract 16, a kidney 11, others 15. A primary focus was not reveled in 18 cases. MRI with double contrast study was compulsory in planning of irradiation. Metastases volume varied from 0.2 up to 20.6 cm3. A dose, delivered to a target margin in SRS, was 14-32 Gy, depending on tumor volume and localization. A total focal dose in SRT, carried out in a mode of hypofractionation, reached 35 Gy; it was 30 Gy (10 sessions) in irradiation of the whole brain. A follow-up period was 21-928 days. Local control of tumor growth was seen in 60% of cases. Positive dynamics of rentgenologic data in SRS and SRT was observed in 90% and 85% of cases, respectively. Survival was dependent on efficacy of treatment of a primary focus and presence of other distant metastases. Possible use of SRS and SRT in intracranial hypertension and metastases localization in deep-lying and eloquent cerebral structures was demonstrated. It should be noted, that these types of pathology, as well as a tumor size, condition a choice of a fractionation mode.