Figure 4
From: Antiproton induced DNA damage: proton like in flight, carbon-ion like near rest
Long-range annihilation particles have RBE similar to X-rays.
(a) Antiproton-nucleon annihilation produces a number of long range particles such gamma rays, neutrons and positive, negative and neutral pions. (b) γ-H2AX foci were scored in cells positioned directly in the beam at the mid-point of the SOBP (solid black circle) and in an adjacent flask at either 28 or 42 mm from the centre of the beam (0 mm). A significant increase in DNA damage was only observed at 1 h after exposure when the in-beam target received 5.56 Gy. P = 0.026 when compared to mock irradiated control by student's T test. Foci were scored in 200 nuclei per sample. (c) Cells were positioned adjacent to in beam samples (approximately 35 mm from the centre of the beam) and were reseeded at clonal density post irradiation in parallel with directly irradiated cells. The dose at 35 mm from the beam centre is estimated to be <10% of the dose at the centre of the beam.
