Outcome of FDG-Avid Areas on PET-CT Scans Organized for Investigation of Head and Neck Malignancy

Abstract

Objectives:

Positron emission tomography (PET) scans may highlight areas of increased fludeoxyglucose (FDG) uptake outside the head and neck (HN) region. These may represent a synchronous malignancy or an area of inflammation or infection. Our study aims to investigate the rate of increased FDG uptake PET scans organized for the investigation of head and neck squamous cell carcinoma (HNSCC) and report on the outcome of these FDG-avid areas.

Methods:

A prospective database of PET scans maintained by the West of Scotland PET Centre was reviewed to identify all scans organized by the head and neck teams between January 2008 and December 2011. Areas with high FDG uptake, above the normal limits for different body tissues at which the radiologists advised further investigation, were noted. Case notes were reviewed and relevant head and neck consultants were contacted to identify further investigations and outcome of these “hot spots.”

Results:

Of 299 PET scans during the study period, 40 FDG-avid areas outside the HN and lung were identified, the majority originating in the colon (56%), followed by the prostate and pelvic region. There were 9 confirmed second primary tumors (22.5%), which is a significant proportion of the group, and half of the group had an incidental high standardized uptake value (SUV; negative investigation). Eleven patients were not investigated due to poor health and palliative management.

Conclusions:

All increased SUV areas outside the head and neck region should be investigated to identify a synchronous primary which may determine a patient’s overall management and long-term outcome.