MSG,
I was with my RO last week, and we were discussing some of these points. HPV can only be detected (at this point) bt testing the actual removed tissue. When my testing was done 5 years ago, the false positives on the actual tissue was up to 20%. It has since improved. He said that there are currently no other acurate ways to test.
All the best,
Rob

6-05, Left Tonsil-T1N2bM0 stageIVA, chemo(Cisplatin), radiation(6660cGy), neck disection, no PEG. HPV negative. (Doc suspects posit)
3-9-09 last of 30 HBO treatments.