PURPOSE: In vitro irradiated blood samples from prostate cancer patients showing late normal tissue damage were examined for lymphocyte response by measuring chromosomal aberrations and proliferation rate.
METHODS AND MATERIALS: Patients were selected from a randomized trial evaluating the optimal timing of dose-escalated radiation and short-course androgen deprivation therapy. Of 438 patients, 3% experienced grade 3 late radiation proctitis and were considered to be radiosensitive. Blood samples were taken from 10 of these patients along with 20 matched samples from patients with grade 0 proctitis. The samples were irradiated at 6 Gy and, along with control samples, were analyzed for dicentric chromosomes and excess fragments per cell. Cells in first and second metaphase were also enumerated to determine the lymphocyte proliferation rate.
RESULTS: At 6 Gy, there were statistically significant differences between the radiosensitive and control cohorts for 3 endpoints: the mean number of dicentric chromosomes per cell (3.26 ± 0.31, 2.91 ± 0.32; P=.0258), the mean number of excess fragments per cell (2.27 ± 0.23, 1.43 ± 0.37; P< .0001), and the proportion of cells in second metaphase (0.27 ± 0.10, 0.46 ± 0.09; P=.0007).
CONCLUSIONS: These results may be a valuable indicator for identifying radiosensitive patients and for tailoring radiation therapy.
Written by:
Beaton LA, Ferrarotto C, Marro L, Samiee S, Malone S, Grimes S, Malone K, Wilkins RC. Are you the author?
Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, ON, Canada.
Reference: Int J Radiat Oncol Biol Phys. 2012 Nov 14. pii: S0360-3016(12)03634-6.
doi: 10.1016/j.ijrobp.2012.09.026
PubMed Abstract
PMID: 23158059
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