Predictive value of 4’-[methyl-11C]-thiothymidine PET volumetric parameters for local control in p16-negative oropharyngeal, hypopharyngeal, and supraglottic squamous cell carcinoma

Abstract

Purpose: We investigated the potential of baseline 4′-[methyl-11C]-thiothymidine ([ 11C]4DST) PET for predicting loco-regional control with head and neck squamous cell carcinoma (HNSCC). Methods: A retrospective analysis was performed using volumetric parameters, such as SUVmax, proliferative tumor volume (PTV), and total legion proliferation (TLP), of pretreatment [11C]4DST PET for 91 patients with HNSCC with primary lesions in the oral cavity, hypopharynx, supraglottis, and oropharynx. As for the oropharynx, p16-negative cases were included. PTV and TLP were calculated for primary lesions and metastatic lymph nodes combined. We examined the association among the parameters and recurrence-free survival (RFS) and whether case selection focused on biological characteristics improved the accuracy of prognosis prediction. Results: The area under the curve (AUCs) using PTV and TLP for the oropharyngeal/hypopharyngeal/supraglottis groups were high (0.91 and 0.87, respectively), whereas that of SUVmax was 0.66 (p < 0.01). On the other hand, the oral group had lower AUCs for PTV and TLP at 0.72 and 0.77. When all cases were examined, the AUC values using PTV and TLP were 0.84 and 0.83, respectively. Conclusion: Baseline [11C]4DST PET/CT volume-based parameters can provide important prognostic information with p16-negative oropharyngeal, hypopharyngeal, and supraglottic cancer patients.