Sandy
The tempol stuff is published in 2005. They describing a mouse model so I doubt that this is ready for human consumption.

The patent is interesting....
supposing (!!) that this works the problem is that you would have to apply the enzyme, arginase to the structure to be protected.
They apparently did work on cell lines in the patent..... Not exactly an organism.

More interesting is a real paper(s) where they describe inhibition of proliferation of cancer cells by the same agent (2007) (liver cancer). So I doubt that either of these are on the menu (or approved) for H&N cancer.

M