If i've had a ct scan of mu lungs and there was a subpleural nodule found 6mm should i get a pet scan? and could this be cancerous?

Very low probability: Lung cancer is very uncommon in your age group. Also nodules located in a sub pleural location have a even lower probability of being malignant. The guidelines recommend a repeat ct scan in one year. This nodule is too small to be evaluated by pet scan.

No: The chances of you having cancer at your young age (25) are rare. The odds of a solitary 6mm lung nodule being cancer in your age are even rarer. A biopsy would be more appropriate if your physicians thought this was cancer.

Not yet: Given your age, if you are at low risk for cancer (non smoker, no other cancer), you should have another chest ct at 12 months (fleischner society criteria). Also, 6 mm is near the limit of spatial resolution of pet/ct and the scan could give a false negative result. This means that even if it was "hot" on pet, the pet/ct could be negative only because the nodule is so small.

No. Unlikely.: At 26 years of age it is highly unlikely that this very small nodule is a cancer unless you have already had or have cancer. A PET scan is unreliable for nodules smaller than 10mm. A nodule of this size can be safely followed for growth with a repeat CT scan in 6 months. If larger then it should be biopsied if unchanged it should be followed for 2 years and if no change then considered benign.