The effect of mild temperature hyperthermia on tumour hypoxia and blood perfusion: relevance for radiotherapy, vascular targeting and imaging.

Clinically achievable mild temperature local hyperthermia (<43 degrees C) has been demonstrated to be an effective adjuvant to radiotherapy in pre-clinical and clinical studies. In this article, we briefly review the recent progress in the following areas: (1) the effect of mild temperature hyperthermia (MTH) on tumour hypoxia and blood perfusion as assessed by dual marker immunohistochemistry (IHC); (2) the kinetics of MTH induced changes in tumour hypoxia; (3) the potential role of heat-induced tumour reoxygenation on radio- and chemo-sensitisation; (4) the potential role of MTH in combination with vascular targeting agents (VTAs) on tumour response; and (5) non-invasive detection of changes in tumour oxygenation and blood perfusion. It is shown that MTH, by itself or in combination with VTAs, leads to changes in tumour perfusion and oxygenation with potential for radio- and chemo-sensitisation.