Hydrogenated oxide material-based hyperthermia and radiotherapy: A new treatment option for esophageal squamous carcinoma.

Abstract

e16127 Background: Radiotherapy (RT) is the mainstay of esophageal squamous carcinoma (ESCC) treatment, and hyperthemia could exert synergistic effects to refractory diseases. Hydrogenated oxide material (HMO) is a newly developed photothermal agent, featured by selectively targeting tumors, high photothermal conversion efficiency under 1064 nm near-infared (NIR) illumination and safe degradation. This study aims at investigating the combination effects of HMO-based hyperthermia and RT in ESCC. Methods: mEC25 murine ESCC cells were cultured and treated with RT alone (prescribed cumulative dose of 10Gy), HMO-based hyperthermia (incubated with 100ug/ml HMO for 20min and irradiated with 1064nm NIR continuously for 15min) or combination therapy (RT followed by HMO-based hyperthermia). FLIR-One was applied to monitor temperature alterations in HMO-based hyperthermia. Flow cytometry was performed to detect apoptosis rates 24h after treatment. Results: The temperature was increased by 21.3[19.8-23.7]℃ after NIR irradiation. The apoptosis rates were 19.4%[19.4%, 19.5%], 43.8%[43.6%, 44.0%] and 61.4%[58.5%, 61.8%] in RT alone, HMO-based hyperthermia and combination therapy group respectively. Considerably low apoptosis rates were observed in HMO-incubation and NIR-irradiation only groups, which was 6.2% and 6.6% respectively, similar to that of treatment-naive cells. Conclusions: The combination of HMO-based hyperthermia and RT provided a promising treatment modality for ESCC, while its effects in rodent models and potentials in clinical practice merit further investigations.