1. Emerging Applications of Ultrasound-Contrast Agents in Radiation Therapy
- Author
-
Dennis B. Leeper, Mohamed Tantawi, John R. Eisenbrey, Quezia Lacerda, and Margaret A. Wheatley
- Subjects
Acoustics and Ultrasonics ,DNA damage ,medicine.medical_treatment ,Biophysics ,Contrast Media ,Article ,Metastasis ,03 medical and health sciences ,Drug Delivery Systems ,0302 clinical medicine ,Neoplasms ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Ultrasonography ,030304 developmental biology ,0303 health sciences ,Microbubbles ,Radiotherapy ,Radiological and Ultrasound Technology ,Tumor hypoxia ,business.industry ,Sonodynamic therapy ,Ultrasound ,Cancer ,medicine.disease ,Radiation therapy ,030220 oncology & carcinogenesis ,Cancer research ,business ,Contrast-enhanced ultrasound - Abstract
Radiation therapy (RT) causes DNA damage through ionization, leading to double-strand breaks. In addition, it generates reactive oxygen species (ROS), which are toxic to tumor cells and the vasculature. However, hypoxic regions in the tumor have been shown to not only decrease treatment response but also increase the likelihood of recurrence and metastasis. Ultrasound-sensitive micro-bubbles are emerging as a useful diagnostic and therapeutic tool within RT. Contrast-enhanced ultrasound (CEUS) has shown great promise in early prediction of tumor response to RT. Ultrasound-triggered micro-bubble cavitation has also been shown to induce bio-effects that can sensitize angiogenic tumor vessels to RT. Additionally, ultrasound can trigger the release of drugs from micro-bubble carriers via localized micro-bubble destruction. This approach has numerous applications in RT, including targeted oxygen delivery before radiotherapy. Furthermore, micro-bubbles can be used to locally create ROS without radiation. Sonodynamic therapy uses focused ultrasound and a sonosensitizer to selectively produce ROS in the tumor region and has been explored as a treatment option for cancer. This review summarizes emerging applications of ultrasound contrast agents in RT and ROS augmentation.
- Published
- 2021