ESTRO 2025 - Abstract Book

S304

Brachytherapy – Head & neck, skin, eye

ESTRO 2025

3235

Digital Poster Novel indexed thermoplastic skin mould design for surface brachytherapy in extremities Kirstie Caravani, Neil Campbell, Kim Kite, Lynsey Hamlett Radiation Oncology, Sunshine Coast University Hospital, Sunshine Coast, Australia

Purpose/Objective: Non-melanoma skin cancer (NMSC) is the most frequently diagnosed cancer in Australia but is not reportable by law to cancer registries [1]. It is reported that Australia has the highest incidence of NMSC in the world [2]. Actinic keratosis (AK) may develop into SCC and there is a prevalence of cases in Australia [3]. Some patients present to our hospital with large superficial NMSC and AK extending around the curvature of extremities and are typically treated with contact brachytherapy or external beam radiotherapy. In this study, we present a novel indexed thermoplastic skin mould design. Material/Methods: All surface moulds are created in-house with thermoplastic bolus and Freiburg Flap (Elekta, Veenendaal, Netherlands). The bolus consists of one layer of Tailorsplint (Rolyan, Patterson Medical, Warrenville, IL) adjacent to the skin surface and at least one layer of Aquaplast Original (Rolyan, Patterson Medical, Warrenville, IL) thermoplastic materials. The thickness of the Aquaplast is varied to allow for improved dose coverage depending on the width of the treatment area. When treating extensive NMSC with or without AK, two shells are created and Freiburg Flap is attached using nylon screws (Figure 1). Additional nylon screws are used to create an indexation point between both halves. Hook and loop straps are attached to edges of both halves to secure the surface mould to the patient. Figures 1 and 2 present examples of this novel custom mould for surface brachytherapy.

Figure 1. Patient with an arm mould during treatment.