Radiosurgical treatment of metastases of renal cell carcinoma on the apparatus "Gamma-knife"
Nikitin D.I., Zubatkina I.S., Ivanov P.I.

Clinic of Radiosurgery, Stereotactic Radiotherapy and General Oncology of the Medical Institute named after Sergei Berezin, St. Petersburg

The aim: to study the results of radiosurgical treatment on the apparatus «Gamma-knife» of patients with metastases of renal cell carcinoma in the brain, to analyze the factors affecting the effectiveness of treatment and the life expectancy of patients.
Patients and methods: from 2009 to 2016, patients with metastases of renal cell carcinoma in the brain who underwent radiosurgical treatment with the Gamma Knife apparatus (Leksell Gamma Knife, Elekta AB, Sweden) with controlled tumor dynamics by MRI imaging and survival time. The study included 101 patients, follow-up data and the results of the control magnetic resonance imaging of these patients were fully available for study. The patients' life expectancy, local control and the appearance of new metastases in the brain after the radiosurgical treatment were studied using the technique of analyzing censored data with the construction of the Kaplan-Mayer probability function. A comparison of life expectancy in groups of patients was carried out using a nonparametric log rank test.
Results: the evaluation of the results of radiosurgery treatment was carried out on the basis of control MR studies using the Gamma-Plan Follow-up program. Local control was achieved in 95% of cases. The emergence of new metastases in the brain was noted in 45% of patients, the median time to detect new metastatic foci in the brain was 10.4 months. Analysis of life expectancy after radiosurgical treatment revealed a median of 13.8 months: in RPA I, 24.9; RPA II - 16.5; RPA III - 4.7 months.
Conclusion: the obtained data showed a high level of local control of metastasis of renal cell carcinoma in the brain after radiosurgical treatment, which, together with the development of methods of systemic therapy, opens the prospect of increasing the life expectancy of patients. Given the radioresistance of metastasis of renal cell carcinoma to radiation therapy and a high rate of relapse after total brain radiation, radiosurgical treatment can be considered a method of choice for the treatment of this group of patients.

Key words: renal cell cancer, metastases to the brain, «Gamma Knife», radiosurgery, local control, life expectancy, RPA-classes
For citation: Nikitin D.I., Zubatkina I.S., Ivanov P.I. Radiosurgical treatment of metastases of renal cell carcinoma on the apparatus «Gamma-knife» // RMJ. 2017. № 16. P. 1164–1168.