Main Session
Sep
27
PQA 02 - Pediatric Cancer, Sarcoma and Cutaneous Tumors, Medical Education & Professional Development, and Health Services Research
2339 - Interstitial and Hybrid HDR vs. PDR Brachytherapy for Non-Melanoma Skin Cancer: Comparative Effectiveness and Toxicity from a Single-Institution Cohort
Presenter(s)
Adam Kluska, MD, PhD - Greater Poland Cancer Center, Poznan, Greater Poland
A. Kluska1, W. Burchardt1,2, F. Oskaldowicz3, A. Swiatlowska3, A. Chichel1, and A. Chyrek1,2; 1Greater Poland Cancer Centre, Poznan, Brachytherapy Department, Poznan, Poland, 2Poznan University of Medical Sciences, Electroradiology Department, Poznan, Poland, 3Poznan University of Medical Sciences, Faculty of Medicine, Poznan, Poland, Poznan, Poland
Purpose/Objective(s):
Non-melanoma skin cancer (NMSC) is the most common malignancy. Both high-dose-rate (HDR) and pulsed-dose-rate (PDR) brachytherapy are used, yet comparative clinical data—particularly for interstitial and hybrid techniques—remain limited. We evaluated treatment outcomes and toxicity of HDR and PDR brachytherapy in a single-institution cohort.Materials/Methods:
We retrospectively analysed 50 lesions in 49 patients treated between 2020 and 2023. The mean age was 75.75 years (range 36–94). Histology included 37 (74%) basal cell carcinoma and 13 (26%) squamous cell carcinoma. Twenty-eight lesions (58%) were primary and 22 (42%) were recurrent after previous surgery. According to AJCC 8th edition, 46% of lesions were T3–T4. Interstitial technique was used in 35 lesions (70%) and hybrid technique in 15 (30%). HDR was delivered in 30 lesions (60%) and PDR in 20 (40%). The median total dose was 40.25 Gy (40–45) for HDR and 49.5 Gy (42.5–60) for PDR. Toxicity was graded using RTOG criteria. Local control was estimated using Kaplan–Meier analysis. Associations between clinical and treatment variables and late toxicity were analysed using univariate analysis.Results:
The mean follow-up was 21.4 months (range 6.4–51.4). Three local recurrences were observed (1 after PDR and 2 after HDR); the Kaplan–Meier 2-year local control rate was 93.6% (95% for PDR vs 93.33% for HDR). Late toxicity grade =3 occurred in 8% of lesions. Higher T stage was significantly associated with increased risk of late toxicity grade =2 (p=0.044), while no significant associations were observed for treatment modality, technique, treatment setting, histology, age, or dosimetric parameters.Conclusion:
Interstitial and hybrid HDR and PDR brachytherapy achieved high local control with acceptable toxicity, including in recurrent and locally advanced tumors. T stage was the main predictor of late toxicity, while no significant differences were observed between HDR and PDR.