Main Session
Sep
28
PQA 04 - Breast Cancer, Patient Reported Outcomes/QoL/Survivorship, Functional Radiation Medicine, Hematologic Malignancies, Palliative Care, and International/Global Oncology
2878 - Adjuvant Post-Operative Interstitial Brachytherapy Versus Superficial X-Ray for Pediatric Keloids: Which to Choose?
Presenter(s)
Soumya Somani, BA - University of Texas Southwestern Medical Center, Dallas, TX
S. Somani1, G. Gard1, B. Bradshaw2, M. Kozak1, K. V. Albuquerque1, P. Nagarkar3, D. Glass4, M. R. Folkert5, C. A. Derderian3, R. D. Timmerman1, and K. A. Kumar1; 1Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX, 2Stanford, Palo Alto, CA, 3Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, 4Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, 5Department of Radiation Oncology, University of Washington, Seattle, WA
Purpose/Objective(s):
After surgical excision of keloids, the risk of recurrence is high, estimated around 70%. Postoperative radiation substantially reduces this risk to 10–20%; however, its use in pediatric patients is not well-documented due to concerns about long-term toxicities, such as secondary malignancies. While multiple options exist for postoperative radiation, such as high dose rate (HDR) brachytherapy and superficial x-ray, data is limited on comparing outcomes in pediatric patients. Although some data suggests that HDR may offer superior local control in adults, we hypothesize that postoperative superficial x-ray achieves noninferior local control rates compared to HDR brachytherapy with similar toxicity in pediatric patients.Materials/Methods:
We conducted an IRB-approved retrospective review of 85 pediatric and adolescent and young adult patients (up to 25 years old) with 143 keloids. Patients were treated post-operatively with HDR brachytherapy or superficial x-rays. Lesions in the HDR group were treated with a median dose of 12 Gy in 3 fractions (range of 12 – 15 Gy in 3 fractions) using an Ir-192 afterloader. Lesions in the superficial group were treated with median of 18 Gy (range of 12 – 20 Gy) at 0.2 – 0.5 cm depth with 80-150 kVp x-rays. Keloid recurrence was the first date a provider noticed clinical regrowth at the previously treated site. Kaplan-Meier curves were used to estimate 1-year local control rates. Patients were excluded if no follow-up was recorded beyond suture removal at 2 weeks post excision.Results:
Median age was 20 years (IQR: 17 – 22 years), and median keloid size was 3 cm (IQR: 2 – 5 cm). The most common location was the earlobe (56%), pinna (15%), trunk (10%), face (4%), and pubic area (4%). 47 lesions (33%) were treated with HDR brachytherapy, and 96 lesions (67%) were treated with superficial x-rays. With a median follow-up of 7 months (IQR: 3 – 16 months), there were 34 recurrences (24%) out of 143 lesions. At 1-year, the local control rate was 73% (95% CI: 59 – 91%) for lesions treated with HDR versus 86% (CI: 78 – 96%) for those treated with superficial x-rays (p=0.6). Including only recurrences that required further excision (n = 10), the local control rate at 1-year for HDR was 88% (95% CI: 75 – 100%) versus 100% (95% CI: 100 – 100 %) for superficial x-rays (p=0.13). The most common toxicity was skin pigment change, with no long-term toxicities or secondary malignancies observed (though only 14 lesions had > 3-year follow-up).Conclusion:
In our study, we found that postoperative superficial x-rays have similar local control to HDR brachytherapy in pediatric keloids, suggesting that superficial x-rays is an appropriate alternative RT option that may be more accessible and easily to deliver. No long-term toxicities were observed including secondary malignancies, though only a smaller subset had >3-year follow-up and thus further follow-up is warranted.