[Fluorine-18]Fluorodeoxyglucose positron emission tomography, DNA ploidy and growth fraction in squamous-cell carcinomas of the head and neck

Background. Positron emission tomography (PET) offers an opportunity to exa mine noninvasively cellular functions with different tracers. [F-18]Fluorod eoxyglucose (FDG) is most commonly used in identifying malignant tumors. Se veral tumor biologic characteristics (tumor cell viability, growth faction, treatment response to radiation, cell membrane dysfunction, recurrence rat e) are suggested to be characterized by [F-18]FDG PET. The aim of this stud y was to assess which other tumor biologic characteristics of squamous-cell carcinoma of the head and neck are correlated with [F-18]FDG PET. Methods: [F-18]FDG PET was performed in 14 patients with squamous-cell carcinomas o f the upper digestive tract (TNM classification T-2-T-4, N-1-N-3). After at tenuation correction, predefined areas of the tumor were semiquantitatively analyzed by the technique of the region of interest and calculated as stan dard uptake values (SUV). Afterwards, 5 biopsies of different tumor regions were obtained during endoscopy in each patient under general anesthesia, a nd a correlation between SUV of [F-18]FDG PET and tumor biologic parameters was attempted. These parameters included: quantitative DNA measurements (i .e. 2c deviation index, 5c exceeding rate), immunohistochemical assessment of growth fraction (i.e. Ki67-MIB-1, PCNA) along with morphological tumor f ront grading. Results: The results revealed a marked variation of prolifera tion and cellular differentiation in various regions of the tumor for all p arameters examined. There was a close correlation between [F-18]FDG uptake and growth fraction (r = 0.83 for Ki67-MIB-1 and r = 0.8 for PCNA). A poor correlation was found between DNA aneuploidy (r = 0.4) or tumor front gradi ng (r = 0.12) and [F-18]FDG uptake. Conclusions: Our results confirm previo us clinical and histologic observations that squamous-cell carcinomas of th e upper digestive tract are heterogeneous tumors. Ki67 antigen, which has b een shown to be of predictive value for proliferation and individual progno sis, correlated with [F-18]FDG uptake. Using [F-18]FDG PET, the main prolif eration centers of inhomogeneous squamous-cell carcinomas could be identifi ed with possible clinical implications for patient management. Copyright (C ) 2001 S. Karger AG, Basel.