Radiat Oncol J.  2023 Mar;41(1):23-31. 10.3857/roj.2022.00521.

Peripheral blood lymphocyte changes after stereotactic ablative body radiotherapy to lung or liver metastases in patients with oligometastatic cancers

• Novikov SN
• Baldueva IA
• Zozulya AY
• Emelyanova NV
• Girdyuk DV
• Arsenyev AI
• Alexandrovna E
• Tyuryaeva EI
• Antipov EIFE
• Girshovich MM
• Kanayev SV

• KMID: 2540751
• DOI: http://doi.org/10.3857/roj.2022.00521

Abstract

Purpose
To perform the analysis of the peripheral blood lymphocyte changes after stereotactic ablative radiotherapy (SABR) in patients with oligometastatic cancers.
Materials and Methods
The dynamics of the immune status in peripheral blood was prospectively evaluated in 46 patients with lung (17 cases) or liver (29 cases) metastases treated by SABR. Flow cytometry of peripheral blood lymphocyte subpopulations was performed before SABR, 3–4 weeks and 6–8 weeks after the end of SABR: 3 fractions of 15–20 Gy or 4 fractions of 13.5 Gy. The number of treated lesions varied from 1 (32 patients) to 2–3 (14 patients).
Results
SABR induced a significant increase of T-lymphocytes (CD3+CD19–) (p = 0.001), T-helper (CD3+CD4+) (p = 0.004), activated cytotoxic T-lymphocytes (CD3+CD8+HLA-DR+) (p = 0.001), activated T-helpers (CD3+CD4+HLA-DR+) (p < 0.001). A significant decrease of T-regulated immune suppressive lymphocytes (CD4+CD25brightCD127low) (p = 0.002) and NKT-cells (CD3+CD16+CD56+) (p = 0.007) was recorded after the SABR. The comparative analysis demonstrated that lower doses of SABR (EQD2Gy(α/β=10) = 93.7–105.7 Gy) induced significant increase of T-lymphocytes, activated cytotoxic T-lymphocytes, and activated CD4+CD25+ T-helpers, while SABR with higher doses (EQD2Gy(α/β=10) = 150 Gy) was not associated with these effects. A more efficient activations of T-lymphocytes (p = 0.010), activated T-helpers (p < 0.001), and cytotoxic T-lymphocytes (p = 0.003) were associated with SABR to a single lesion. A significant increase of T-lymphocytes (p = 0.002), T-helpers (p = 0.003), and activated cytotoxic T-lymphocytes (p = 0.001) was observed after SABR for hepatic metastases in contrast to SABR for lung lesions.
Conclusion
Changes in peripheral blood lymphocytes after SABR could be influenced by the location or the number of irradiated metastasis, and the dose of SABR.

Keyword

Stereotactic ablative radiotherapy; Abscopal; Immune system; Irradiation; Systemic effects