Killing two birds with one stone: Abscopal effect mechanism and its application prospect in radiotherapy.

Abscopal effects are characterized by the emergence of neoplasms in regions unrelated to the primary radiation therapy site, displaying a gradual attenuation or regression throughout the progression of radiation therapy, which have been of interest to scientists since Mole's proposal in 1953. The incidence of abscopal effects in radiation therapy is intricately linked to the immune system, with both innate and adaptive immune responses playing crucial roles. Biological factors impacting abscopal effects ultimately exert their influence on the intricate workings of the immune system. Although abscopal effects are rarely observed in clinical cases, the underlying mechanism remains uncertain. This article examines the biological and physical factors influencing abscopal effects of radiotherapy. Through a review of preclinical and clinical studies, this article aims to offer a comprehensive understanding of abscopal effects and proposes new avenues for future research in this field. The findings presented in this article serve as a valuable reference for researchers seeking to explore this topic in greater depth.

Gadolinium Oxide Nanoparticles Reinforce the Fractionated Radiotherapy-Induced Immune Response in Tri-Negative Breast Cancer via cGAS-STING Pathway.

Introduction: Radiotherapy is a widely recognized first-line clinical treatment for cancer, but its efficacy may be impeded by the radioresistance of advanced tumors. It is urgent to improve the sensitivity of radioresistant tumors to radiotherapy. In this work, gadolinium oxide nanocrystals (GONs) were utilized as radiosensitizers to enhance the killing effect and reinforce the immune activation of X-ray irradiation on 4T1 breast cancer cells in vitro and in vivo. Methods: 1.0 T small animal MR imaging (MRI) system was employed to trace GONs in vivo, while 225 kVp X-ray irradiation equipment was utilized for investigating the radiosensitization of GONs in 4T1 breast cancer cells in vitro and in vivo. Western blot, quantitative real-time PCR (RT-qPCR), immunohistochemistry, immunofluorescence, clonal survival assay, flow cytometry and reactive oxygen species assay were used to explore the biological mechanism of GON sensitization. Results: GONs exhibited exceptional utility as contrast agents for both in vivo and in vitro MRI imaging. Interestingly, a single dose of 8.0 Gy X-rays together with GONs failed to confer superior therapeutic effects in tumor-bearing mice, while only 3.0 Gy × 3 fractions X-rays combined with GONs exhibited effective tumor growth inhibition. Moreover, fractionated X-ray irradiation with GONs demonstrated a superior capacity to activate the cGAS-STING pathway. Discussion: Fractionated X-ray irradiation in the presence of GONs has demonstrated the most significant activation of the anti-tumor immune response by boosting the cGAS-STING pathway.

LiveObj: Object Semantics-based Viewport Prediction for Live Mobile Virtual Reality Streaming.

Virtual reality (VR) video streaming (a.k.a., 360-degree video streaming) has been gaining popularity recently as a new form of multimedia providing the users with immersive viewing experience. However, the high volume of data for the 360-degree video frames creates significant bandwidth challenges. Research efforts have been made to reduce the bandwidth consumption by predicting and selectively streaming the user's viewports. However, the existing approaches require historical user or video data and cannot be applied to live streaming, the most attractive VR streaming scenario. We develop a live viewport prediction mechanism, namely LiveObj, by detecting the objects in the video based on their semantics. The detected objects are then tracked to infer the user's viewport in real time by employing a reinforcement learning algorithm. Our evaluations based on 48 users watching 10 VR videos demonstrate high prediction accuracy and significant bandwidth savings obtained by LiveObj. Also, LiveObj achieves real-time performance with low processing delays, meeting the requirement of live VR streaming.