Application of a burn scar assessment tool for the evaluation of visual scarring following immunocryosurgery for facial basal cell carcinoma

Abstract

The therapeutic interventions for basal cell carcinoma (BCC) impact facial cosmesis. Our aim was to assess the aesthetic burden of facial BCC treatment by evaluating the extent of the tumour site visually based on clinical images before and after immunocryosurgery; a minimally invasive combination treatment of topical imiquimod and cryosurgery. A three-item (texture, height, colour) burn scar scale was independently applied by four physicians (two dermatologists and two plastic surgeons) on archival semi-standardized clinical images of facial BCC before and one year after immunocryosurgery. The score assessments were compared using non-parametric statistical tests; internal consistency (reliability) and inter-rater agreement were assessed using Cronbach's α and Gwet's AC2, respectively. Images (before and one year after treatment) of 27 BCCs from 26 patients (15 males) were analysed. The reliability was good (α>0.80) for all items before surgery and for colour after surgery. The inter-rater agreement was acceptable (AC2>0.70) for all items except for height pre-treatment (AC2 = 0.482). Based on averaging of all raters, cosmesis improved significantly after treatment at all tumour sites (p<0.001, Wilcoxon signed ranks test). The main limitations of the study are the inclusion of cases from a single centre and its retrospective nature. The evaluated burn scar scale can be reliably used to compare the extent of the BCC site visually before therapy and after resultant scars have formed. In this way, the impact of therapeutic interventions on cosmesis (from tumour to scar) can be evaluated, particularly for less aggressive facial skin tumours, such as most BCC.