We examined the usefulness of a double-staining method using iodine solutions of different concentrations for the excision of T1, T2 squamous cell carcinomas （SCCs） of the tongue. We studied 127 patients who were given a diagnosis of T1, T2 SCCs of the tongue at Maxillofacial Surgery, Tokyo Medical and Dental University from 2000 through 2010. The patients were classified into 2 groups. One group, consisting of 89 cases, underwent staining once with 3% iodine solution （single-staining group: Group I）. The other group, consisting of 38 cases, underwent staining with 3% iodine solution and then with 5% iodine solution （double-staining group: Group II）. The excision margin of the lesion was designed to be about 10 mm outside of the border of the unstained areas （USAs） and stained areas （SAs）. Then the lesion was excised. In addition, the borders of the SAs and USAs were examined, and any recurrence after excision was noted. The type of lesion, type of epithelial dysplasia at the surgical margin, and recurrence rate were compared between the two groups. Local recurrence and the presence of epithelial dysplasia at the surgical margin in SCCs cases were seen in 12/127 cases （9.4%） and 58/127 cases （45.7%）, respectively. The numbers of the surgical marginpositive cases were 47/89 cases （52.8%） in Group I and 11/38 （28.9%） in Group II. The rate of SCC recurrence was significantly lower in Group II than in Group I （p=0.01）. The number of cases with local recurrence was 12/89 （13.5%） in Group I, but 0/38 （0%） in Group II. These results suggest that the double-iodine-staining method indicated the border of epithelial dysplasia more clearly than the single-staining method. Therefore,the double-iodine-staining method is useful for determining the excision margin of SCCs of the tongue.
