Applications of Low Energy Megavoltage X-ray Beams in Cancer Radiotherapy
Ying Zhang
Department of Biomedical Engineering, Tianjin University, Tianjin, China and Department of Therapeutic Radiology, Yale University, New Haven, CT, USA.
Yuanming Feng
Department of Biomedical Engineering, Tianjin University, Tianjin, China.
Jun Deng *
Department of Therapeutic Radiology, Yale University, New Haven, CT, USA.
*Author to whom correspondence should be addressed.
Abstract
A review on the applications of low energy megavoltage (MV) X-ray beams (1-4 MV) in cancer radiotherapy is presented. Firstly, the physical characteristics of low energy megavoltage X-ray beams are reviewed in terms of penumbra, dose fall-off, exit dose, dose to bone, penetration power, skin dose and image quality. Secondly, the therapeutic applications of low energy megavoltage X-rays in cancer radiotherapy are further stratified and discussed based on X-ray energy levels. Thirdly, a systematic review of imaging applications of low energy megavoltage X-ray beams in image-guided radiation therapy (IGRT) and megavoltage fan beam computed tomography (MVFBCT) is provided. Finally, we summarize the latest development of low energy megavoltage X-ray beams in cancer radiotherapy and cancer imaging during the past twenty years. With their intrinsic physical characteristics, it is feasible to achieve personalized radiotherapy and personalized imaging protocols for individual patient. However, further technological developments and more clinical data would be needed to fully exploit the potentials of low energy megavoltage X-ray beams in the personalized radiotherapeutic management of cancers.
Keywords: Low energy megavoltage X-rays, cancer radiotherapy, cancer imaging, personalized radiotherapy, personalized imaging protocols.