Oxygen microbubbles improve tumor control after radiotherapy in a rat fibrosarcoma model

摘要

It is well-established that tumor hypoxia negatively impacts treatment outcome for radiation therapy (RT). In particular, tumor cell resistance to radiotherapy is increased 3-fold under anoxic conditions. Hypoxia hinders direct "oxygen radiosensitization" (increased free radical oxidative damage and formation of difficult-to-repair organic peroxides during RT), but also promotes radioresistance through biological HIF-1 complex signaling. Oxygen microbubbles (OMB) have been successfully used as an oxygen-delivery vehicle, improving the efficacy of sonodynamic therapy. Furthermore, the robust oxygen-delivery potential of OMB is demonstrated by their ability to sustain asphyxiated animals for over two hours. Here we assess whether these microbubbles can be used to relieve tumor hypoxia and thereby improve RT outcome.