TITLE:
Distance to Isocenter Directly Affects Margin and Inappropriate Margin Increases the Risk of Local Control Failure in LINAC-Based Single-Isocenter SRS or SRT for Multiple Brain Metastases
AUTHORS:
Junfang Gao
KEYWORDS:
Single-Isocenter Multiple Target, SRS/SRT, AHARA, Winston-Lutz-Gao Test
JOURNAL NAME:
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology,
Vol.11 No.2,
May
24,
2022
ABSTRACT: =In the advancement of single-isocenter multiple target treatment in the
LINAC-based SRS or SRT, the target distance to the isocenter and grouping of multiple
targets are the highly concerned and debatable topics in the SRS/SRT field at
present. Three failure and success cases of local control in our early
practices are presented in this study and it indicated that the target distance
to the isocenter directly affects the margin and an inappropriate margin
increase the risk of local control failure. The GTV expansion margin should be
LINAC-specific and institute-specific. Within the physics and dosimetry scope,
the AHARA (as high as reasonably achievable) principle is the first time
proposed to the radiation oncology field. Radiobiology and tumor response
complexity is beyond this study.