Funding for this research was provided by:
The National Key Research and Development Program of China (2017YFC0108603)
Science and Technology Commission of Shanghai Municipality (19411951000)
Article History
Received: 23 May 2020
Accepted: 6 December 2020
First Online: 10 December 2020
Ethics approval and consent to participate
: As a retrospective study, the work was approved by the Shanghai Proton and Heavy Ion Center Institutional Review Board.
: Not applicable.
: The authors declare that they have no competing interests.