2721 - Dermoscopic Evaluation of Radiation-Induced Dermatitis In Breast Cancer Patients Receiving Adjuvant Radiotherapy

Purpose/Objective(s): Radiation-induced dermatitis (RID) is the most common acute toxicity of radiotherapy in breast cancer patients and is typically assessed using clinical grading systems such as RTOG criteria, which rely on visible skin changes. Subclinical alterations may occur earlier and remain undetected. Dermoscopy is a non-invasive imaging modality capable of visualizing microscopic skin changes. We hypothesized that dermoscopy can detect early subclinical radiation-induced skin changes and that dermoscopic findings correlate with clinical RTOG grading. This study aimed to characterize dermoscopic features of RID and evaluate their association with clinical severity.

Materials/Methods: In this prospective observational study, 10 postoperative breast cancer patients receiving adjuvant radiotherapy were enrolled. Five underwent breast-conserving surgery and five modified radical mastectomy. Radiotherapy consisted of 40 Gy in 15 fractions over 3 weeks, with an additional tumor bed boost of 10 Gy in 4 fractions for breast-conserving cases. Baseline dermoscopic assessment was performed prior to treatment, followed by weekly dermoscopic and clinical evaluations during radiotherapy. Both polarized and non-polarized dermoscopy were used. Dermoscopic features were recorded and correlated with weekly RTOG acute toxicity grades using chi-square testing.

Results: At clinically normal skin (Grade 0), dermoscopy demonstrated early changes including diffuse pigmentation network (64%), perifollicular pigmentation (42%), and erythema in over half of patients. At Grade 1, pigmentation network was present in 100%, perifollicular pigmentation in 95%, and erythema in 76%. Grade 2 showed universal presence of pigmentation, perifollicular pigmentation, and erythema, indicating progression. Grade 3 demonstrated necrosis in 100% of cases along with persistent pigmentation and erythema; necrosis was exclusive to Grade 3. Significant associations were observed between dermoscopic findings and RTOG grade, including scaling (?²=313, p<0.001), pigmentation network (?²=119, p<0.001), perifollicular pigmentation (?²=169, p<0.001), and erythema (?²=229, p<0.001). Dermoscopic abnormalities consistently preceded or accompanied clinical changes.

Conclusion: Dermoscopy detects early subclinical skin alterations during radiotherapy and shows strong correlation with clinical RTOG grading. This modality may serve as a sensitive complementary tool for monitoring RID, enabling earlier identification and intervention. Incorporation of dermoscopic assessment into routine practice could improve toxicity monitoring, guide supportive care, and inform development of refined grading approaches in future research.