Residual γH2AX foci predict local tumour control after radiotherapy

Radiother Oncol. 2013 Sep;108(3):434-9. doi: 10.1016/j.radonc.2013.06.022. Epub 2013 Jul 25.


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.

Keywords: Biomarker; DNA repair; Local tumour control; Radiotherapy; Tumour micromilieu; γH2AX.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Squamous Cell / pathology
  • Carcinoma, Squamous Cell / radiotherapy*
  • Cell Line, Tumor
  • Head and Neck Neoplasms / pathology
  • Head and Neck Neoplasms / radiotherapy*
  • Histones / analysis*
  • Humans
  • Mice
  • Squamous Cell Carcinoma of Head and Neck


  • H2AX protein, human
  • Histones