Radiation induced early nuclear changes in cytologic brush specimens from the upper aerodigestive tract.

Objective: To evaluate the feasibility of DNA image cytometry to assess radiation induced early nuclear changes in cytologic smears from the upper aerodigestive tract.

Methods: 100 cytologic brush specimens from 50 postoperatively irradiated patients with upper aerodigestive tract carcinoma were examined Smears were taken from clinically inconspicuous mucosa from the former tumor site and from a control region (contralateral side). Cellular DNA was quantified using the CAS 200 image analysis system on Feulgen stained slides. DNA histograms were evaluated using the coefficient of variation (CV), the DNA index (DI), the 2c deviation index (2cDI) and the 2.5c exceeding rate (2.5cER).

Results: All specimens from the control region were diploid. Forty-six smears from the former tumor region were diploid and in four cases non-diploid cells were found. Single cells with a DNA content exceeding 5c ('5c exceeding events'), were identified in three non-diploid and six diploid smears from the former tumor region.

Conclusion: DNA analysis is a useful tool in detecting early nuclear changes preceding morphologic changes.