Detecting normal cell radiosensitivity via assay of DNA damage in lymphocytes for individualizing radiotherapy in head and neck cancer patients.
OBJECTIVE
The purpose of this study was to determine whether the distribution of radiosensitivities in normal tissues of head and neck cancer patients, measured using a DNA damage assay on lymphocytes, is likely to provide sufficient discrimination to enable reliable identification of patients with abnormal sensitivities.


METHODS
Radiosensitivity was assessed in 307 lymphocyte samples from unselected head and neck cancer patients and was quantified as the initial number of DNA double-strand breaks (dsb) induced per Gray and per DNA unit (200 Mbp).


RESULTS
The existence of an inter-individual variation in the radiosensitivity parameter is described by the range (0.41--9.38 dsb/Gy/DNA unit) of the values found. We detected 37 patients who developed severe skin reactions during radiotherapy treatment and we compared their radiosensitivity values with the remaining patients treated. Radiosensitivity values of >7.20 dsb/Gy/DNA unit should theoretically correspond to highly radiosensitive patients.


CONCLUSIONS
Our results suggest that initial DNA damage measured on lymphocytes offers an approach to predict the acute response of human normal tissues prior to radiotherapy. .
Wang
Wei-Dong
WD
Department of Oncology, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China. wwdlr@yahoo.com
Chen
Zheng-Tang
ZT
Li
De-Zhi
DZ
Cao
Zheng-Huai
ZH
Pu
Ping
P
Fu
Shang-Zhi
SZ
Chen
Jie
J
Sun
Shi-Liang
SL
Chen
Xiao-Pin
XP
D004249:DNA Damage / Q000528:radiation effects*; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000532:radiotherapy*; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects*; D012372:ROC Curve; D011836:Radiation Tolerance / Q000235:genetics*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity