Tumor tissue often outgrows its oxygen supply and cellular metabolism declines to a lower level. Poorly metabolizing tumor tissue is well known to be highly resistant to radiation – as witnessed by the frequent relapses suffered by cancer patients after receiving conventional treatment.
Tumor hypoxia (oxygen deprivation) inhibits radiation therapy: hypoxic cancerous tumor cells are 2 to 3 times less susceptible to radiation than oxygenated tumor cells.
For decades, cancer researchers have been searching for an agent that will safely re-oxygenate tumor tissue, increasing metabolic activity within the cells and causing a corresponding increase in the tumor killing power of radiation therapy. Until now, despite the expenditure of billions of research dollars, the search for a new drug that can safely and effectively “sensitize” cancerous cells to radiation therapy has been unsuccessful.