title: Antiproton induced DNA damage: proton like in flight, carbon-ion like near rest.
abstract: Biological validation of new radiotherapy modalities is essential to understand their therapeutic potential. Antiprotons have been proposed for cancer therapy due to enhanced dose deposition provided by antiproton-nucleon annihilation. We assessed cellular DNA damage and relative biological effectiveness (RBE) of a clinically relevant antiproton beam. Despite a modest LET (~19 keV/μm), antiproton spread out Bragg peak (SOBP) irradiation caused significant residual γ-H2AX foci compared to X-ray, proton and antiproton plateau irradiation. RBE of ~1.48 in the SOBP and ~1 in the plateau were measured and used for a qualitative effective dose curve comparison with proton and carbon-ions. Foci in the antiproton SOBP were larger and more structured compared to X-rays, protons and carbon-ions. This is likely due to overlapping particle tracks near the annihilation vertex, creating spatially correlated DNA lesions. No biological effects were observed at 28-42 mm away from the primary beam suggesting minimal risk from long-range secondary particles.
authors: Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, UK. j.kavanagh@qub.ac.uk
authors: J N
authors: JN
authors: Kavanagh
authors: F J
authors: FJ
authors: Currell
authors: D J
authors: DJ
authors: Timson
authors: K I
authors: KI
authors: Savage
authors: D J
authors: DJ
authors: Richard
authors: S J
authors: SJ
authors: McMahon
authors: O
authors: O
authors: Hartley
authors: G A P
authors: GA
authors: Cirrone
authors: F
authors: F
authors: Romano
authors: K M
authors: KM
authors: Prise
authors: N
authors: N
authors: Bassler
authors: M H
authors: MH
authors: Holzscheiter
authors: G
authors: G
authors: Schettino
mesh_terms: D002244:Carbon / Q000737:chemistry* / Q000494:pharmacology; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D004249:DNA Damage; D006801:Humans; D007477:Ions / Q000494:pharmacology; D011522:Protons; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D012062:Relative Biological Effectiveness; D014965:X-Rays
chemical_list: D007477:Ions; D011522:Protons; D002244:Carbon
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