Efficacy of PDD-guided tumor excision combined with photodynamic therapy in high-risk basal cell carcinoma

• PDD-guided excision achieved a higher negative margin rate with fewer frozen sections, enhancing surgical precision. • Adjunctive PDT may help eliminate subclinical residual tumor cells beyond histologically clear margins. • The combined approach resulted in superior cosmetic outcomes and higher patient satisfaction. Basal cell carcinoma (BCC) is the most common non-pigmented cutaneous malignancy. Photodynamic diagnosis (PDD) can distinguish tumor tissues from normal tissues by visible fluorescence. Photodynamic therapy (PDT) is widely used in the treatment of non-melanoma skin tumors. This study aims to illustrate the efficacy and safety of PDD-guided tumor excision combined with ALA-PDT in patients with BCC. A retrospective cohort study was conducted on 19 patients diagnosed with high-risk BCC, who were grouped based on the actual treatment they had received in clinical practice: the PDD group (n=9) and the non-PDD group (n=10). Patients were not randomized. The PDD group were treated with PDD-guided tumor excision, and the non-PDD group were treated with wide local excision (WLE). Both groups underwent frozen section analysis, and PDT was performed intraoperatively or postoperatively as an adjunctive therapy to target potential subclinical residual tumor cells. Clinical outcomes were analyzed, including efficacy, aesthetic outcome, patient satisfaction, and quality of life. The negative rate of tumor margins in PDD group was 95.3%, compared to 75.5% in the non-PDD group. PDD group needed fewer times of frozen section analysis and observed better cosmetic outcomes and superior patient satisfaction. PDD can reveal tumor margins in high-risk BCC to guide the extent of surgical resection. The combination of PDD-guided tumor resection with PDT demonstrates high safety and efficacy in the treatment of BCC, particularly in managing potential subclinical residual disease. However, it still needs to be verified in studies with larger sample sizes and longer follow-up periods.