Portland, the PET is accurate as it measures sugars given off by the reproducing cancer cells, so if it is beyond a microscopic level (ie too small to register), it is very accurate. In fact you are more likely to have a false positive than a false negative. I had a false positive PET due, likely, to the foods I was eating prior to the PET (I was on a limited diet and couldn't avoid the carbs or I wouldn't have been able to eat).