In vivo radiobiological characterization of proton beam at the National Cancer Center in Korea: effect of the Chk2 mutation.

Purpose: The relative biological effectiveness (RBE) in the presence or absence of CHK2 was estimated at the Korean National Cancer Center Proton Therapy Center (NCCPTC).

Methods And Materials: The proton beam was fixed at 210 MeV with 6-cm spread-out Bragg peaks (SOBPs) because this is expected to be the most frequently used clinical setting. X-rays were obtained using a 6-MV conventional linear accelerator.

Relative biologic effectiveness determination in mouse intestine for scanning proton beam at Paul Scherrer Institute, Switzerland. Influence of motion.

Purpose: To determine the relative biologic effectiveness (RBE) of the Paul Scherrer Institute (PSI) scanning proton beam in reference conditions and to evaluate the influence of intestine motion on the proton dose homogeneity.

Methods And Materials: First, RBE was determined for crypt regeneration in mice after irradiation in a single fraction. Irradiation was performed at the middle of a 7-cm spread out Bragg peak (SOBP; reference position), as well as in the proximal part of the plateau and at the distal end of the SOBP.