Custom Made Skin Flap for HDR Treatment of Skin Lesions
Abstract
Purpose
The aim of the current study is the development of a novel custom skin flap (CSF) for HDR treatment of skin lesions, as well as, assess the usability and planning technicalities of our CSF in a clinical setup.
Methods
Our CSF was constructed by acrylic beads easily available online with an outer diameter of 10mm and a 2mm hole, and bronchial catheters 5F from Varian. Each catheter was inserted through the beads of the desired length and a button shape plug was placed on the tip of the catheter to stop the beads removed. For the same cause a thin tape was applied at the other end of the CSF and once the desired shape of the CSF was defined both sides were taped and wrapped with a clear plastic stretch wrap to support its rigidity and preservation of its shape.
Results
A total set of 3 tests were conducted to validate the accuracy of dose delivery and usability of our method on a clinical setup. Firstly, a positioning test confirmed the correct digital reconstruction of the catheters and positional accuracy of the source on a Perma-Doc Phantom (VariSource HDR). The next two tests aim to assess the accuracy of dose delivery for a small treated area (i.e. nasal lesion) and a larger area with irregular L-shape (i.e. shoulder lesion).
Conclusion
Source positioning accuracy was within 1mm as we visually verified for all eight dwell positions from the registered radiographs. Dose delivery verification analysis from the Mapcheck software was based on the ƴ index with (3mm, 3%) criteria and a threshold of 15%. The ƴ rate was 90.6% for the small treatment area and 90.9% for the L-shape area