Intratumor Textural Heterogeneity on Pretreatment 18F-FDG PET Images Predicts Response and Survival After Chemoradiotherapy for Hypopharyngeal Cancer

Abstract

Background: Increasing evidence suggests that intratumor heterogeneity of solid tumors characterized by textural features on 18-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) images is associated with response to chemoradiotherapy (CRT) and survival. The current study aimed to determine whether a similar relationship exists in hypopharyngeal squamous cell carcinoma (HPSCC). Methods: This study investigated 27 patients with HPSCC who underwent cisplatin-based induction chemotherapy followed by definitive CRT underwent pretreatment 18F-FDG PET/CT. Standardized uptake value (SUV), metabolic tumor volume (MTV), and textural features (coarseness, busyness, complexity, and contrast) of primary tumors were measured. Patients were classified as nonresponders or responders according to the response evaluation criteria in solid tumors. The capacity of each parameter to classify response was assessed using the Mann–Whitney U test. Cox-proportional hazard models were used to identify variables associated with disease-free survival (DFS) and overall survival (OS). Results: Of 70 patients, 58 (83 %) had complete or partial response after CRT. Responders showed lower maximum SUV (P = 0.037), lower MTV (P = 0.039), lower coarseness (P < 0.001), and busyness (P = 0.015) compared with nonresponders. Multivariate analysis showed that high coarseness (P = 0.001, hazard ratio [HR] 5.65; 95 % confidence interval [CI] 2.12–15.07) and busyness (P = 0.045; HR 2.56; 95 % CI 1.02–6.42) were independently associated with poor DFS, and that high coarseness (P = 0.013; HR 2.48; 95 % CI 1.21–5.09) was independently associated with poor OS. Conclusion: Abnormal coarseness in baseline 18F-FDG PET scans may be useful for predicting response and survival after CRT in HPSCC patients.