The Role of 18-Fluoro-2-Deoxy-Glucose Positron Emission Tomography/Computed Tomography as Response and Prognosis Predictive Factor of Concurrent Chemoradiotherapy after Induction Chemotherapy in Head and Neck Squamous Cell Carcinoma: A Prospective Study.

The importance of induction chemotherapy (ICT) followed by concurrent chemoradiotherapy (CCRT) has been re-established in recent years aiming at fewer metastatic sites and better control of the disease. We prospectively studied the possibility of early prediction of overall survival (OS) and progression-free survival (PFS) after 3 cycles of chemotherapy with doxetacel, cisplatin and 5-fluorouracil using 18-fluoro-2-deoxy-glucose positron emission tomography computed tomography (F-FDG PET/CT) in patients with head and neck squamous cell cancer. To our knowledge, this is the first such study. Thirty-five patients were studied. They underwent an F-FDG PET/CT examination twice: a day before ICT and 10⁻14 days after the last cycle of ICT. Tumor-standardized uptake value (SUVmax) and hypermetabolic tumor volume were measured on both scans. The mean age of patients was 56.5 years. Complete responses to CCRT PFS and OS were calculated. : Our results showed that a decrease of ≥30% in the SUVmax value after ICT was a prognostic factor of tumor response to PFS and OS ( = 0.026 and = 0.021). The groups of patients with a SUVmax between 10 and 14.5 in the primary tumor on a pre-ICT F-FDG PET/CT scan had statistically shorter PFS and OS ( = 0.001, = 0.006) when compared with other groups of patients with SUVmax less than 10 or SUVmax more than 14.5. A decrease of less than 55% of hypermetabolic tumor volume of the primary tumor was significantly related to poor prognosis in PFS and OS ( = 0.033, = 0.017). SUVmax and hypermetabolic tumor volume measured on F-FDG PET/CT after ICT might be valuable prognostic tools for predicting OS and PFS and, thus, for the selection of patients with head and neck cancer who will benefit from CCRT.