Abstract 2543: Dynamic whole-body PET/CT can predict the treatment response to chemoradiotherapy of esophageal cancer patients

Abstract Background: Majority of positron emission tomography-computed tomography (PET/CT) studies are based on static images. However, dynamic whole-body PET-CT (DW-PET/CT) enables quantification of tissue glucose metabolism dynamics. The purpose of this study is to investigate whether DW-PET/CT can predict the treatment response in esophageal squamous cell carcinoma (ESCC) patients treated with chemoradiotherapy (CRT). Methods: Fifty ESCC patients who underwent pretreatment DW-PET/CT were evaluated. DW-PET/CT parameters of the main tumor including Patlak slope (PS, absolute rate of tracer consumption) and Patlak intercept (PI, degree of tracer perfusion in the tumor) were calculated using 4 whole-body PET/CT image series acquired at every 5 minutes from 60 minute after injection of 18F-fluorodeoxyglucose. The maximum standardized uptake value (SUVmax) of the tumor was also measured at 60 minute of the tracer injection. The relationships of these PET derived parameters with treatment response was analyzed. Results: Treatment responders were 34 patients, while non-responders were 16 according to the RECIST criteria. Tumors of responders showed significantly higher SUVmax, PS and PI than non-responders (P=0.03, 0.0003, 0.001, respectively). PS and PI showed a good performance to predict the treatment response with AUC of 0.75 and 0.79, whereas SUVmax showed a poor performance with AUC of 0.69. Tumor contraction rate during CRT showed significant positive correlation with PS and PI (P=0.005, 0.03, respectively). Conclusions: DW-PET/CT might enable pretreatment prediction for the treatment response to CRT in ESCC patients. Citation Format: Yoshihiro Kurata, Moe Iwata, Koichi Hayano, Yasunori Matsumoto, Ryota Otsuka, Akira Nakano, Tadashi Shiraishi, Nobufumi Sekino, Toyozumi Takeshi, Masaya Uesato, Gaku Ohira, Hiisahiro Matsubara. Dynamic whole-body PET/CT can predict the treatment response to chemoradiotherapy of esophageal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2543.