Lung Metastasis? - 1262263

My father was diagnosed and successfully treated for stage iv oropharyngeal cancer in 2007. Cancer had spread to lymph nodes on left side of neck which were all removed. Following treatment he endured multiple surgeries and difficulties due to osteonecrosis of the right mandible which was rebuilt w his leg bone--flap failed and had a pectoral flap done. Following this he has had neck and chest wounds that will not heal. Before treatment in 07 he was 190 lbs-now down to 108 lbs w GI tube as he cannot chew/swallow solids. Wound care noticed infection coming from elsewhere and suspected a new tumor so they ordered a ct. Ct showed mass in right neck suspicious for malignant mass as well as a 3.1x4.2x2.8 cm subpleural noncalcified irregular mass in left pulmonary apex and a 2cm anterior subpleural mass in right lung base. He was referred for a full-body PET w CT attenuation. This showed suspicious changes throughout tongue, SUV 3.93; left lower lobe lung metastasis of 1.6cm with SUV 2.64, and right midsternal lytic metastasis of 2x2.9 cm with SUV 5.8. Obviously we are extremely concerned as the oncologist said lung or sternum metastasis means treatment would be palliative only. So, we were sent to his ENT who said his tongue showed no sign of recurrence whatsoever and who suspects the suspicious sternum area is infection due to the wound issue on his chest and that perhaps the lower left lung area is just inflammation or infection? Just really confused as to why the first CT and the PET/CT are so different and why the oncologist and the ENT would have such different takes on the imaging results..but really would just like to make some sense out of these results. Thank you so very much for your time and consideration.