Main Session

Sep 29

PQA 07 - Head and Neck Cancer, Lung Cancer/Thoracic Malignancies, and Nursing and Supportive Care

3584 - Superficial Hypofractionated Radiation Therapy for Nonmelanoma Skin Cancer (NMSC): Comparable Outcomes across Fractionation Schedules

03:45pm - 05:00pm ET

Poster Hall - Exhibit Hall A

Screen: 15

POSTER

Presenter(s)

Jessica Ortega, MD - UC Health, Cincinnati, OH

J. S. Ortega¹, V. Leonardo², W. L. Barrett³, S. Medek³, L. E. Pater², K. P. Redmond², T. D. Struve III¹, H. R. Esslinger¹, and J. R. Kharofa³; ¹Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, ²University of Cincinnati, Cincinnati, OH, ³Department of Radiation Oncology, University of Cincinnati Cancer Center, Cincinnati, OH

Purpose/Objective(s):

Superficial X-ray therapy (SXRT) is an established treatment for nonmelanoma skin cancer (NMSC). Guidelines recommend a range of biologically effective doses, but comparative data for hypofractionated superficial regimens, particularly <10 fractions, are limited and largely derived from brachytherapy series. Shorter regimens may offer improved convenience. We compared local control and toxicity across commonly used hypofractionated SXRT regimens.

Materials/Methods:

Single-institution retrospective cohort study of patients with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) treated with definitive SXRT from 2016–2025. Regimens included 30 Gy/5 fx daily, 40 Gy/10 fx daily, 36 Gy/6 fx twice weekly, and 42 Gy/7 fx twice weekly. The primary endpoint was local recurrence (LR) defined as time from treatment to last follow up or local failure event. Toxicity was graded using CTCAE v6.

Results:

A total of 172 lesions in 75 patients were analyzed with median follow-up of 87 months. Two LR were observed, yielding 2-year local control of 98.8% for all patients with high rates across fractionation schemes (93-100%, table). Both LR occurred in patients treated with 42 Gy/7 fx, without significant difference (p=0.09) compared to other regimens. One local recurrence occurred in each histologic group at 7.57 and 7.67 months for BCC and SCC, respectively (p = 0.80). Grade =2 dermatitis occurred in 20.3% (35/172) of lesions, with no association between fractionation and toxicity (table). Dermatitis rates were 16% (23/143; grade 2=8, grade 3=15) for 2–4 cm cones versus 38.7% (12/31; grade 2=1, grade 3=11) for 6–10 cm cones (p=0.03).

Conclusion:

Hypofractionated SXRT provides excellent local control and favorable toxicity across regimens. Dermatitis was associated with field size rather than dose/fractionation scheme. Given comparable outcomes, regimen selection may be guided by patient preference and logistical considerations.

Fractionation	BED10 (Gy)	N (lesions)	Local Recurrences (n)	Local Control at 2 yrs (%)	Grade =2 Dermatitis (%)
30 Gy in 5 fx daily	48.0	33	0	100.0	28.6
36 Gy in 6 fx 2×/wk	57.6	28	0	100.0	5.7
42 Gy in 7 fx 2×/wk	67.2	46	2	93.3	23.9
40 Gy in 10 fx daily	56.0	65	0	100.0	18.5
Overall	—	172	2	98.4	20.3