Corrigendum: Radioactivity and space range of ultra-low-activity for in vivo off-line PET verification of proton and carbon ion beam-a phantom study - Fuquan Zhang; Fuquan Zhang; Fuquan Zhang; Fuquan Zhang; Junyu Zhang; Junyu Zhang; Junyu Zhang; Junyu Zhang; Yan Lu; Yixiangzi Sheng; Yun Sun; Jiangang Zhang; et al. (Frontiers Media S.A., 2024)