Role of Lugolís iodine in identifying the transformation zone for treatment Ė Pre-treatment assessment
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VIA-positive women who are eligible for treatment by ablative methods in a screen-and-treat setting can be further assessed after application of Lugolís iodine before treatment. However, this assessment is not mandatory and should be practised only in settings with a regular supply of Lugolís iodine solution.
Assessment of the size of the lesion:
Assessment of the size of the lesion tends to be more precise after application of Lugolís iodine, because of the strong colour contrast between the normal area and the abnormal area. Lesions that occupy less than 75% of the ectocervix are eligible for treatment by ablation. The presence of bright yellow or mustard yellow abnormal epithelium on a background of brown normal epithelium provides a better approximation of the percentage of the cervix occupied by the abnormal epithelium, and thus helps in correctly selecting cases for ablation.
Assessment of the margins of the lesion:
Sometimes the margins of thin acetowhite lesions are not obvious, and this may give rise to dilemmas in deciding on the area to be treated. In such situations, the colour contrast produced by Lugolís iodine permits easy identification of the margins of the lesions and thereby helps to determine the extent of the area for treatment.
Assessment of the size of the probe for ablative treatment:
Applying Lugolís iodine to the cervix helps in the selection of the appropriate size of the probe for cryotherapy or thermal ablation for treatment of the abnormal area on the cervix. The margins of the lesion are sharply delineated by the colour contrast produced by Lugolís iodine, which isolates the area to be treated. This helps in choosing a suitable size of the probe that will adequately cover the abnormal area.
Assessment of the number of applications of the selected probe:
Sometimes the shapes of lesions are such that they cannot be effectively covered by a single application of the largest cryotherapy probe. Such lesions are best treated by multiple, overlapping applications of a small thermal ablation probe. When performing treatment by multiple applications, delineation of the outer margins of the lesion can become tricky. In such circumstances, the colour contrast produced by Lugolís iodine helps in correctly determining the peripheral margins of the lesions, which can otherwise be missed during treatment.