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Updated: May 9, 2026

An Automated Microscopic Scoring Method for the γ-H2AX Foci Assay in Human Peripheral Blood Lymphocytes
Published on: December 25, 2021
Residual γH2AX foci predict local tumour control after radiotherapy
Ulrike Koch1, Katharina Höhne, Cläre von Neubeck
1German Cancer Consortium (DKTK), Dresden and German Cancer Research Center (DKFZ), Heidelberg, Germany; Department of Radiation Oncology and OncoRay - National Center for Radiation Research in Oncology, Medical Faculty and University Hospital Carl Gustav Carus, Technische Universität Dresden, Germany.
Purpose:
Evaluation of micromilieu-dependent quantified γH2AX foci as a potential predictive biomarker in well-oxygenated tumour areas in 9 HNSCC xenograft models in vivo.
Materials & Methods:
GammaH2AX foci were quantified in perfused tumour areas 30 min (initial γH2AX foci) and 24 h (residual γH2AX foci) after exposure to a single dose of 4 Gy. The initial and residual normalised γH2AX foci were correlated with TCD50 after single dose irradiation under clamped blood flow (SDclamp) or a fractionated irradiation setting under ambient blood flow (fx).
Results:
A significant negative correlation between initial and residual normalised γH2AX foci and TCD50 SDclamp and TCD50 fx for 9 HNSCC tumour xenograft models in vivo was found. Residual normalised γH2AX foci showed higher intertumoural variability and their correlation with TCD50 was more robust.
Conclusions:
For the first time a significant negative correlation between γH2AX foci and local tumour control after irradiation has been demonstrated. Our results underline the potential of residual γH2AX foci as a predictive biomarker for local tumour control after radiotherapy.

