On the other hand, Kang et al and Jang et al reported favorable results
with 60 Gy in three fractions of X-ray SBRT for HCC
[23, 24]. While the optimal dose to HCC in X-ray SBRT is
not established, 60 Gy in four fractions can be applied in
clinical settings. Therefore, we think that 60 Gy in four
fractions of X-ray SBRT could be candidate to compare
against of 60 Gy(RBE) in four fractions of C-ion RT for
this dosimetric comparative study. Second, this was a
mono-institutional study, and thus policy of the planner
could have produced some subjective bias. Treatment
plans for each modality were made by staff members of
varying experience levels who were blinded to each other.
Both of the planners were also blinded to the clinical
results of C-ion RT to reduce bias as much as possible.