Premature chromosome condensation associated with fluorescence in situ hybridisation detects cytogenetic abnormalities after a CT scan: evaluaton of the low-dose effect.
The purpose of this study was to assess the cytogenetic effects of the X ray irradiation used during a CT scan in order to estimate the mean absorbed dose in circulating lymphocytes. Chromosomal aberrations were scored in blood lymphocytes of ten patients undergoing CT scans, by applying fluorescence in situ hybridisation (FISH) to metaphase cells and premature chromosome condensation (PCC) with chromosomes 1, 3 and 4 painting probes immediately after exposure. This generated a dosimetric index that reflects the dose to the circulating lymphocytes. By using PCC a significant increase in the frequency of chromosomal fragment was observed immediately after a CT scan. However, no significant increase in chromosomal aberration was detected in metaphase cells. The mean dosimetric index immediately after exposure was 0.057 Gy (95% CI: 0.052-0.082 Gy). This dosimetric index depends essentially on the size of the examined and exposed blood volumes. This dose is in close agreement with the dose length product (DLP) (Gy cm) (R = 0.80). It should be kept in mind when justifying requests for diagnostic CT scan especially in young patients. The presence of chromosomal fragments after a CT scan indicated the cytogenetic effect of a low dose. PCC associated with chromosome painting is a method for detecting the cytogenetic effect of a low dose immediately after exposure.
M'kacher
R
R
Department of Medicine, UPRES EA 27-10 Institut Gustave Roussy, 94805 Villejuif, France.
Violot
D
D
Aubert
B
B
Girinsky
T
T
Dossou
J
J
Béron-Gaillard
N
N
Carde
P
P
Parmentier
C
C
D000328:Adult; D000818:Animals; D001769:Blood / Q000528:radiation effects; D016466:CHO Cells / Q000528:radiation effects; D002277:Carcinoma / Q000000981:diagnostic imaging; D002869:Chromosome Aberrations; D019457:Chromosome Breakage; D020223:Chromosome Painting; D002875:Chromosomes / Q000528:radiation effects; D002877:Chromosomes, Human / Q000528:radiation effects*; D002878:Chromosomes, Human, Pair 1 / Q000528:radiation effects / Q000648:ultrastructure; D002893:Chromosomes, Human, Pair 3 / Q000528:radiation effects / Q000648:ultrastructure; D002894:Chromosomes, Human, Pair 4 / Q000528:radiation effects / Q000648:ultrastructure; D006224:Cricetinae; D003412:Cricetulus; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging; D006801:Humans; D007399:Interphase; D008214:Lymphocytes / Q000528:radiation effects* / Q000648:ultrastructure; D008297:Male; D008677:Metaphase; D008875:Middle Aged; D008938:Mitosis / Q000528:radiation effects; D019047:Phantoms, Imaging; D011874:Radiometry / Q000295:instrumentation; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000009:adverse effects*; D014178:Translocation, Genetic; D014571:Urologic Neoplasms / Q000000981:diagnostic imaging