DS29 Intraoperative marking and photographs to facilitate the optimal planning of adjuvant radiation treatment

Abstract

Surgical excision is curative for most cutaneous squamous cell carcinomas (cSCCs). Mohs micrographic surgery (MMS) can offer superior cure rates, particularly in cases with high-risk features. However, it is not infallible and adjuvant radiotherapy (ART) may be considered in such cases. To maximize the effectiveness of ART, oncologists require information on histological tumour parameters, staging investigations and the immune status of the patient. The precise location and dimensions of the surgical defect must be accurately communicated to maximize efficacy and minimize the toxicity of ART. In many cases, particularly after MMS, reconstruction with flaps displaces the original surgical margins, often producing complex scars and making accurate radiation planning more challenging. This increases the risk of ART not treating or undertreating at-risk areas and causing unnecessary morbidity. A pragmatic solution developed at our tertiary cutaneous oncology unit utilizes intraoperative markings with high-quality photographs to provide accurate information about the surgical defect and its relationship to the reconstructed wound to facilitate accurate ART planning. We will present the biopsy site of a local recurrence of a high-risk cSCC in a 68-year-old immunocompetent man. MMS confirmed a poorly differentiated, infiltrative SCC invading skeletal muscle with perineural invasion of nerves > 0.1 mm (Brigham and Women’s Hospital T3). The resultant defect was 5.5 cm in diameter. A transposition flap was used for reconstruction and a referral for ART was planned. Crosses were marked at points measured 2 cm from the periphery of the defect. Photographs were taken and archived. A postoperative photograph is taken demonstrating displacement of the surgical margins by the flap. When viewed in the context of the original defect it facilitates accurate and effective planning of adjuvant treatment. We highly recommend photographs of the surgical defect and repair with use of peripheral markers in cases of reconstruction by tissue rearrangement to facilitate this process.