Novalis Tx radiosurgical platform experience in National Medical Research Centre for Oncology of the Ministry of Health of Russian

Abstract

Purpose of the study . The primary study presents an analysis of the results of stereotactic radiosurgery (SRS) and hypofractionated stereotactic radiotherapy (SRBT) of extra — and intracranial tumors obtained during four years of observation at «National Medical Research Centre for Oncology». Material and methods. The study enrolled 277 patients. 184 patients (66.4%) received SRS, 54 patients (19.5%) received intracranial SRT, 39 patients (14.1%) received extracranial SRBT. Radiation treatment plans were developed with iPlan and Elements planning software, BrainLab. Radiation therapy was performed with Novalis Tx, Varian linear accelerator. Outcome assessment was performed with iPlan and Elements software, BrainLab, by comparing tumor volumes based on brain MRI series for brain tumors (or CT imaging for extracranial pathology) before the treatment and during four-year follow-up. Stereotactic radiosurgical and hypofractive radiotherapy techniques were used. In radiosurgical surgery, radiation therapy was performed with a single high-precision approach of the therapeutic dose to the target for the purpose to reach biological effect in the irradiated volume with minimal impact on the surrounding tissues. Single focal doses (SFD) were selected due to histology, and the dose was prescribed according to the accepted criteria of The International Commission on Radiation Units and Measurements (ICRU) (2010) Report 83. Hypofractionated stereotactic radiotherapy was performed using 2-5 Fractions (FR) with an average range of 3-10 Gy. Results. During the entire period of observation tumor volume and clinical symptoms in patients who received SRS were reported to reduce in 69,8%, to be stable in 19,6%, increased in 9,8%, respectively. For patients, who received intracranial SRT, tumor volume and clinical symptoms were reported to reduce in 59,3%, increased in 21,4%, to be stable in 9,3%. For patients with extracranial tumors, who went SRBT, tumor volume and clinical symptoms were reported to be stable in 58,9%, reduced in 38,5%, increased in 6,7%. Conclusion. The analysis of the obtained data shows the high efficiency of SRS and SRBT methods, which allow to achieve local control over both malignant and benign tumours.