Adding whole-body PET-FDG to the pre-therapeutic conventional staging of head and neck squamous cell carcinoma improved the TNM [tumor, node and metastasis] classification of the disease and altered the management of 13.7 percent of patients, according to a study published in the February issue of the Journal of Clinical Oncology.
Max Lonneux, MD, from the departments of nuclear medicine, head and neck surgery, radiation oncology and maxillofacial surgery, Cliniques Universitaires Saint-Luc in Brussels, and colleagues included his 233 patients in this multicenter, prospective study with newly diagnosed and untreated head and neck squamous cell carcinoma.
Researchers first determined the TNM stage and therapeutic decision based on the conventional work-up (including physical exam, CT/MRI of the head and neck region, and thoracic CT) and sealed in envelope. They then performed whole-body PET-FDG, and subsequently wrote TNM stage and therapeutic decision in a sealed envelope.
The investigators also recorded changes in TNM stages and in patient management as a result of PET-FDG imaging. Clinical outcome and histopathology were used as gold standards to validate the TNM stage. Conventional and PET stages were compared using the McNemar test.
According to the authors, conventional and PET stages were discordant in 43 percent of the patients. PET proved to be accurate in 47 patients and inaccurate in 13 patients. TNM status was left unconfirmed in 40 patients because no therapeutic change was expected from the stage difference.
The researchers found that conventional plus PET TNM classification (envelope two) was significantly more accurate than conventional classification (envelope one, McNemar test). PET-FDG altered the therapeutic plan in 13.7 percent of the 233 patients.
“Our results support the implementation of PET-FDG imaging in the routine imaging work-up of head and neck squamous cell carcinoma," Lonneux and colleagues concluded.