This study reported treatment results of 24 patients with ICC treated with respiratory-gated PBT at a dose of 48-83.6 GyRBE in 20-38 fractions. This study reported the 2-year overall survival, progression-free survival, and local tumor control rates were 51%, 26%, and 73%, respectively.

Local tumor control rates were non-inferior to those reported in previous studies using fiducial markers. The authors concluded that respiratory-gated PBT without fiducial markers is an effective and less invasive treatment option for ICC, showing potential for improved local control and tolerable adverse effects.