Prognostic value of metabolic tumor volume in recurrent and/or metastatic head and neck squamous cell carcinoma treated with platinum-based chemotherapy

Abstract

Background: The standard first‐line treatment for recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC) is platinum‐based chemotherapy, while the predictor of survival has yet to be established, except for tumor human papillomavirus (HPV) status. The present study aimed to evaluate the usefulness of metabolic tumor volume (MTV) measured on FDG‐PET/CT in predicting survival of patients with R/M HNSCC after platinum‐based chemotherapy. Methods: Patients with R/M HNSCC treated with platinum‐based chemotherapy as first‐line treatment following FDG‐PET/CT between 2006 and 2017 at Osaka University Medical School Hospital and Osaka International Cancer Institute were eligible. Exclusion criteria were nasopharyngeal carcinoma, >60 days duration between FDG‐PET/CT and chemotherapy initiation. FDG‐PET/CT data were transferred into the workstation in the DICOM format. A total amount of MTV in the whole body was measured using a SUV‐based automated contouring program (PETSTAT Viewer Ver. 2.2), with the SUV threshold being 2.5. Tumor HPV status was determined by p16 immunohistochemistry. The risk of death was assessed by Cox proportional hazard model. Results: One hundred and four patients met the criteria. The median follow‐up duration of surviving patients was 13.1 months (range, 3.2‐79.6). The median MTV was 21.9ml (range, 0.0‐1118.7). The risk of death increased by 1.03 fold (95% confidence interval, 1.02‐1.04; P<0.0001) for every 10‐ml increment of MTV, independently of tumor HPV status. The median overall survival was 15.3 months in patients with MTV larger than the median and 9.2 months in patients with MTV equal to or smaller than the median. Conclusions: MTV is a useful predictor of survival in patients with R/M HNSCC after platinum‐based chemotherapy. MTV needs to be considered in allocation for randomized clinical trials.