Gamma knife radiosurgery compared to whole brain radiation therapy enhances immunity via immunoregulatory molecules in patients with metastatic brain tumours

• Published in: British journal of neurosurgery 2020-12, Vol.34 (6), p.604-610
• Main Authors: Hatiboglu, Mustafa Aziz, Kocyigit, Abdurrahim, Guler, Eray Metin, Nalli, Arife, Akdur, Kerime, Sakarcan, Ayten, Ozek, Erdinc, Uysal, Omer, Mayadagli, Alpaslan
• Format: Article
• Language: English
• Subjects: Brain; Brain cancer; Brain Neoplasms - radiotherapy; Brain Neoplasms - surgery; Cytokines; gamma knife radiosurgery; Humans; Immune system; Immunity; Metastasis; radiation; Radiation therapy; Radiosurgery; Retrospective Studies; Tumors
• ISSN: 0268-8697; 1360-046X
• DOI: 10.1080/02688697.2019.1642445

Background: There is lack of data on the effect of stereotactic radiosurgery in modulation of the immune system for cancer patients with metastatic brain tumours. Therefore, we investigated the change in levels of immunoregulatory molecules after Gamma Knife radiosurgery (GKR) and whole brain radiation therapy (WBRT) in patients with brain metastases. Methods: Peripheral blood samples were collected from 15 patients who received GKR, nine patients who received WBRT for brain metastases and 10 healthy controls. Samples were obtained at three time points such as before, 1h after and 1 week after the index procedure for patients treated with GKR or WBRT. All patients' demographic data and radiosurgical parameters were retrospectively reviewed. We analyzed the change in the levels of T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death ligand-1 (PD-L1), and cytokines such as IL-2, IL-10, IFN-γ, TNF-α after GKR and WBRT using Enzyme-linked immunosorbent assays (ELISA). Results: Baseline level of IFN-γ was found to be lower and that of PD-L1 was higher in the GKR group compared to WBRT group and healthy controls (p