Long-Term Outcomes of Image-Guided Superficial Radiation Therapy for Stage I–II Nonmelanoma Skin Cancer: A Real-World Retrospective Cohort Study
Year: 2026
Type: article
Abstract: Image-guided superficial radiation therapy (IGSRT) is increasingly utilized for the treatment of nonmelanoma skin cancer (NMSC). Although prior studies, including extensive multi-institutional cohorts, have reported local control rates exceeding 99% for early-stage basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) treated with IGSRT, data on long-term efficacy and adverse reactions remain limited. This study aims to evaluate the long-term efficacy and safety of IGSRT for stage I–II BCCs and SCCs. This retrospective cohort study analyzed outcomes from stage I–II BCC and SCC tumors treated with IGSRT per the Ladd–Yu protocol between 2016 and 2023. The primary aim was to assess freedom from recurrence (FFR), via Kaplan–Meier (KM) survival analysis at 2 and 5 years. The secondary aim was to compare the Radiation Therapy Oncology Group (RTOG) toxicity scores of three IGSRT dosing protocols: 3 fractions/week, 4 fractions/week, and 5 fractions/week. A total of 10,248 patients with 13,357 lesions were included in this study (8729 BCCs and 4628 SCCs). The Kaplan–Meier estimated FFR was 99.7% and 99.6% for stage I and stage II lesions, respectively (n = 8485 NMSCs). Similarly, 5-year FFR for stage I and II lesions were both 99.7% (n = 2427 NMSCs). There were 3697 patients (36.1%) lost to follow-up at 2 years and 2942 (61.5%) lost to follow-up at 5 years. No statistically significant differences in FFR were observed between stages (P > 0.05) within histologic type (i.e., BCC or SCC). Most lesions (97.5%) developed mild RTOG toxicities (RTOG 0–2), while 2.5% developed severe toxicities (RTOG 3–4). NMSCs had statistically similar probability of severe toxicities, regardless of the number of radiation fractions/week (P > 0.05). Patients with tumors of the head or neck had reduced risk of severe toxicities (P = 0.004) while patients with stage II tumors were more likely to experience severe toxicities (P < 0.001). These findings confirm the durable long-term control of NMSC treated with IGSRT following the Ladd–Yu protocol inclusive of high-resolution dermal ultrasound, with predominantly mild adverse reactions. These data support the use of IGSRT as a primary treatment of stage I and II NMSC lesions. Nonmelanoma skin cancers (NMSC) are the most common cancers worldwide. These cancers are especially common in older adults and are becoming more frequent as the population ages. In the USA, more than 5 million new cases are diagnosed each year. Although surgery is commonly used to treat NMSC, image-guided superficial radiation therapy (IGSRT) is an effective nonsurgical treatment option. IGSRT uses ultrasound imaging to help direct radiation precisely at the cancer while minimizing damage to nearby healthy skin. This study was conducted by researchers in the USA using patient data collected from several dermatology practices across the country. We studied the largest group of patients treated with IGSRT reported to date. We focused specifically on basal cell and squamous cell carcinomas, which have a higher risk of recurrence than very superficial tumors confined to the top layer of the skin (in situ). We aimed to evaluate how well IGSRT works over the long term and how safe it is in real-world clinical practice. We reviewed outcomes from more than 13,000 skin cancer lesions treated between 2016 and 2023. We found that fewer than 1% of treated cancers returned within 5 years after treatment. In addition, more than 97% of patients experienced either no side effects or only mild, temporary skin irritation. We conclude that IGSRT is a safe and effective treatment option for patients with NMSC and provides an important alternative to surgery.
Source: Dermatology and Therapy
Institutions: Rosalind Franklin University of Medicine and Science, Jesse Brown VA Medical Center, University of South Dakota, Case Western Reserve University, Emory University, Rutgers, The State University of New Jersey, Weill Cornell Medicine, University of North Texas Health Science Center, Baylor Scott & White Health
Language: English
Subfield: Dermatology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $7,400
OpenAlex ID: W7225649262