Redox Status of the Blood of Patients with Metastatic Brain Lesion During Different Options of Radiotherapeutic Treatment

Abstract

Purpose: A comparative study of the content of lipid peroxidation (LPO) products and the activity of the main antioxidant enzymes in the blood plasma of patients with brain metastases (BM) under various radiotherapeutic treatment options.Material and methods: The study included 37 patients with BM. Three groups of patients were formed: Control group (12 patients), in which stereotactic radiotherapy with a single focal dose of 6 Gy to a total dose of 30 Gy was performed on the place of the removed metastasis; Main group No. 1 (6 patients) — after a session of preoperative radiosurgery with a dose of 10-15 Gy, the metastatic focus was removed after 24 hours; Main group No. 2 (19 patients) — staged radiosurgery (SRS) was carried out in 3 stages with a dose of 10 Gy with an interval between sessions of 14 days (total dose of 30 Gy). In the blood plasma of 37 patients, the content of malondialdehyde (MDA), diene conjugates (DC), and the activity of superoxide dismutase and catalase were determined by standard spectrophotometric methods. The comparison group included 21 people without cancer (donors). Statistical processing of the results was carried out using the Statistica 10.0 program. using Student’s t-test and nonparametric Mann–Whitney test.Results: Before treatment, the MDA content was increased in all patients, on average by 83.5 % (p = 0.00025) relative to the donor group; in the majority, DC was also increased (by 60.4 %, p = 0.0498). After removal of the metastatic lesion in patients in the Control and Main group No. 1, the level of LPO products remained elevated. And only in the Main Group No. 2, already before the 3rd session of SRS, a decrease in the level of MDA was observed in patients with a removed primary lesion, as well as normalization of DC in all patients and restoration of the coordinated work of antioxidant enzymes. An increase in MDA content with reduced catalase activity in patients with an unremoved primary lesion at the stages of SRS may reflect the mechanism of tumor cell reduction under the influence of increased production of free radicals during long-term radiation exposure.Conclusions: The use of SRS, in contrast to other radiotherapy options, helps to normalize the redox status of the blood of patients with metastatic brain lesions. Analysis of the data obtained suggests greater effectiveness of SRS in patients with a removed primary lesion.