Fasting before PET scan

This PET was acquired from a male patient suffering from a metastatic disease ,
The first (Upper row) was taken after breakfast but he told the invistigator that he was fasting,
PET scan showed minor tumor activity in mediastinal area while CT showed large masses,
Four days later PET was performed again (the patient was fasting that time) which showed the realistic tumor metabolism and multiple metastasis in lung , liver ......(click the image for larger view).