Objective: Human papillomavirus (HPV) has been usually associated with gynaecological cancers; however, recent studies have shown that this virus plays an important role in head and neck cancer. The aim of this study was to correlate PET/CT parameters in HPV-positive (HPV) and HPV-negative (HPV) patients using three tracers showing glucose metabolism, proliferation and hypoxia.
Patients and methods: Thirty-six patients (10 females and 26 males) with newly diagnosed head and neck cancer were enroled to this retrospective study. All patients underwent a series of three PET/CT scans with fluorine-18-fluorodeoxyglucose (F-FDG), fluorine-18-fluorothymidine (F-FLT) and fluorine-18-fluoromisonidazole (F-FMISO). Scans were performed on separate days, within a time-frame of 2 weeks. We compared several PET/CT parameters grading tumour biology including maximum standardized uptake value (SUV), total lesion glycolysis, totalSUV and heterogeneity between HPV and HPV patients. For statistical analysis, t-test and Mann-Whitney test were used and the materiality level of P values less than 0.05 were considered significant.
Results: Patient with HPV showed higher SUV values than patients with HPV in F-FLT images (6.34±2.5 vs. 5.99±3.6) and F-FMISO images (1.66±0.33 vs. 1.62±1.28) and lower values in F-FDG images (9.99±3.85 vs. 10.28±2.44). However, analyzing total lesion glycolysis values in all tracers, HPV patients showed higher values than HPV patients [F-FDG (92.21±102.9 vs. 70.83±74.27), F-FMISO (30.75±30.1 vs. 25.13±31.34) and F-FLT (138.71±132.9 vs. 109.61±92.7)].
Conclusion: In our preliminary and limited study, we did not observe statistically significant differences in tumour metabolism, proliferation and hypoxia between the HPV and HPVpatients. However HPV patients tend to have higher proliferation status and more pronounced hypoxia with lower glucose metabolism.