Cytogenetic Effects of Radiotherapy on Peripheral Blood Lymphocytes of Cancer Patients / 대한암학회지

ABSTRACT

PURPOSE: To evaluate the frequency and types of chromosome aberrations induced by ionizing radiation in cancer patients before and after radiotherapy. MATERIALS AND METHODS: Thirty cases with various types of cancers such as rectum, lung, uterine cervix, lymphoma, and etc. were studied. The time of analyses was within 1 month after radiotherapy. The mean total radiation dose was 54 Gy. RESULTS: The incidence of aberrant metaphases prior to radiation treatment was 2.2% and increased significantly after treatment to 29.7% (p<0.001). Also the number of chromosomal aberrations per cell was increased by a factor of 38.5. A comparison of chromosome abnormalities observed before and after treatment indicated that dicentrics, acentrics, derivatives and translocations were increased by a factor of 155.5, 99, 55.5 and 23.8, respectively, after radiation treatment. Breakages were located at all chromosomes except Y chromosome and total number of identifiable breakages was 426 in 900 observed lymphocyte metaphases. Distribution of break points revealed the increase of number of break points in chromosome 1,2,5 and 11q. CONCLUSION: Ionizing radiation produces more asymmetrical than symmetrical chromosome aberrations and more two-break than one-break anomalies in radiation-treated cancer patients.