A method for determining resection margins in basal cell carcin oma of the skin

Purpose of the study. To investigate the feasibility of applying a method of visual diagnosis of basal cell carcinoma (BCC) under ultraviolet (UV) light using Photoditazine for determining tumor margins in clinical practice. Patients and Methods. The study was conducted at the Department of Reconstructive and Plastic Surgery and Oncology, National Medical Research Center for Oncology. Sixty patients (men and women) with cytologically verified stage I–II BCC were included. Among them, 30 patients (15 men and 15 women) presented with a superficial growth pattern, and 30 patients (15 men and 15 women) with a solid growth pattern. In all cases, Photoditazine gel-penetrant was applied topically to the tumor surface and the surrounding area (1.5–2 cm) for 30 minutes. The gel was then removed with a gauze swab moistened with distilled water. Under UV light in a dark room, a characteristic fuchsia fluorescence of the tumor and a pale or dark-red halo around the lesion were observed. This enabled assessment of the tumor spread into adjacent tissues that initially appeared visually unaffected. Results. The study yielded the following findings: in 33 patients, the peritumoral area showed no fluorescence, whereas in 27 patients, zones of enhanced fluorescence ("hot spots") were detected around the tumor. These areas exhibited a round or irregular shape and were characterized by an intense dark-red fluorescence surrounding the tumor focus. Extensive "hot spots" indicated active adsorption of the photosensitizer in the area, which may result from altered hormonal and metabolic properties of the peritumoral skin. In cases where extensive peritumoral fluorescence was identified, the area should be included within the resection field as a potentially high-risk zone for subsequent recurrence. Conclusion. The proposed method is simple to use, does not require expensive equipment or systemic administration of the photosensitizer, and therefore avoids patient inconvenience and precautionary restrictions. Detection of peritumoral fluorescence enables accurate determination of true tumor margins and facilitates subsequent surgical excision with an optimal margin from the visible edge of the lesion. These advantages support the recommendation of this method for broad implementation in routine practice of specialized medical institutions.