The diagnostic value of positron emission tomography (PET) with radiolabelled fluorodeoxyglucose (F-18-FDG) in head and neck cancer

Positron emission tomography (PET) scanning has recently been introduced in to clinical practice but its usefulness in the management of head and neck cancer is not well defined. The aim of this prospective preliminary study w as to examine the clinical value of fluorodeoxyglucose (FDG) - PET in patie nts with head and neck cancer treated by radiotherapy with surgery in reser ve by (i) relating quantitative uptake of isotope to tumour type and histol ogical grade and (ii) comparing the imaging findings of PET and magnetic re sonance imaging (MRI) in post-radiotherapy assessment of tumour response. T wenty-one patients had pre-treatment PET and MRI scans and these were repea ted four and eight months after treatment if there was no clinical relapse. Pre-treatment uptake of FDG using tumour to cerebellar ratio parameters wa s significantly related to the histological grade of squamous cancer (p = 0 .04) but not to tumour type. Discordance of post-treatment PET/MRI findings in one case indicates a possible role for PET in the early detection of tu mour recurrence. Other potential uses of PET scanning in the management of head and neck cancer are discussed.