title: Biodosimetry of heavy ions by interphase chromosome painting.
abstract: We report measurements of chromosomal aberrations in peripheral blood lymphocytes from cancer patients undergoing radiotherapy treatment. Patients with cervix or esophageal cancer were treated with 10 MV X-rays produced at a LINAC accelerator, or high-energy carbon ions produced at the HIMAC accelerator at the National Institute for Radiological Sciences (NIRS) in Chiba. Blood samples were obtained before, during, and after the radiation treatment. Chromosomes were prematurely condensed by incubation in calyculin A. Aberrations in chromosomes 2 and 4 were scored after fluorescence in situ hybridization with whole-chromosome probes. Pre-treatment samples were exposed in vitro to X-rays, individual dose-response curves for the induction of chromosomal aberrations were determined, and used as calibration curves to calculate the effective whole-body dose absorbed during the treatment. This calculated dose, based on the calibration curve relative to the induction of reciprocal exchanges, has a sharp increase after the first few fractions of the treatment, then saturates at high doses. Although carbon ions are 2-3 times more effective than X-rays in tumor sterilization, the effective dose was similar to that of X-ray treatment. However, the frequency of complex-type chromosomal exchanges was much higher for patients treated with carbon ions than X-ray.
authors.affiliation: National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Durante
authors.forename: T
authors.initials: T
authors.lastname: Kawata
authors.forename: T
authors.initials: T
authors.lastname: Nakano
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Tsujii
mesh_terms: D000368:Aged; D002247:Carbon Isotopes; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy; D002453:Cell Cycle / Q000528:radiation effects; D002869:Chromosome Aberrations; D020223:Chromosome Painting; D002889:Chromosomes, Human, Pair 2; D002894:Chromosomes, Human, Pair 4; D004307:Dose-Response Relationship, Radiation; D004938:Esophageal Neoplasms / Q000532:radiotherapy; D005260:Female; D020450:Heavy Ions; D006801:Humans; D007399:Interphase; D008214:Lymphocytes / Q000166:cytology; D008297:Male; D008875:Middle Aged; D010315:Particle Accelerators; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011882:Radiotherapy, High-Energy; D012062:Relative Biological Effectiveness; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy; D014965:X-Rays
chemical_list: D002247:Carbon Isotopes