Dose Computation of Keloids in Brachytherapy: Tg-43 or Model-Based-Dose-Calculation?

Abstract

To evaluate the safety and cosmetic results (cosmetic outcomes and toxicity) of a novel (shortened) fractionation scheme using custom made surface molds for treatment of non-melanoma skin cancer (NMSC) with High Dose Rate (HDR) Brachytherapy. Materials and Methods: This is a retrospective review of our experience with 38 patients (42 non-melanoma skin cancers) treated between February 2003 and December 2014 with HDR Brachytherapy. There were 22 males and 16 females with ages ranging from 37 to 101 years. A shortened HDR fractionated schedule of 10 fractions with 4.85 Gy or 5 Gy each given twice weekly in 5 weeks was used. The tumor dose was equivalent to the conventional external beam radiation therapy (EBRT), usually given in 30 fractions of 2 Gy/day. Individually designed applicators were used in all patients; the size and shape of these varied according to the characteristics of the tumor and its location. Cosmesis was rated as excellent, good, fair or poor using a standardized cosmesis scale (RTOG) as reported by Cox et al. and acute and late toxicity were rated using Criteria for Adverse Events (CTCAEv4). Results: The follow-up period ranged from 4 to 152 months (median 85 months). Local control was 95% with two patients (5%) developing recurrent disease at the follow up time. Good to excellent cosmetic results were achieved in all patients. Conclusions: Brachytherapy is a safe and efficacious treatment option in the management of skin cancer patients. It may be especially useful to treat irregularly shaped lesions and at locations that are difficult to access. Based on this experience, the use of HDR brachytherapy delivered with custom made skin applicators may prove to be especially advantageous for patients with NMSC in anatomical locations where surgery could be mutilating. It is also a viable option for treating older patients and those with busy schedules, in whom the alternative would be several weeks of conventional EBRT.