The Carl Zeiss INTRABEAM system is a mobile compact miniature x-rays device which delivers treatment by various techniques; including intraoperative, interstitial, intra-cavity, and surface treatments. The main purpose of the study was to observe dose homogeneity in surface applicator overlapping and non-overlapping region using 3D printed bolus in INTRABEAM System for skin cancer treatment. Dose uniformity plays a crucial role between overlapping and non-overlapping region of applicator during dose delivery in skin cancer. The different thickness, shape (concave, convex) and filament densities of ABS (Acrylonitrile Butadiene Styrene) were made to form main body parts of bolus for surface applicator of diameter 4 cm in Carl Zeiss INTRABEAM system with the help of German RepRap 3D printer. Concave and Convex part refer to the structures similar to the cross section of concave and convex lens respectively. GafChromic eBT films which were irradiated with 50 kV x-ray with surface applicator in presence of bolus. After that films were scanned with an EPSON® Expression 10000 XL/Pro flatbed scanner and dose profile were plotted with ImageJ Software, from which dose homogeneity was determined. The dose profiles were plotted for the different combination (filament density) of concave and convex parts of bolus (printed from 3D printer) with thickness 5 mm, 6 mm, 7 mm, 8 mm, 9 mm and 10 mm. From the plotted profiles, the maximum flat profile was seen in the bolus with thickness 10 mm and combination of concave filament density 45% and convex filament density 100%.The dose homogeneity is better achieved for the INTRABEAM system Surface applicator at overlapping and non-overlapping region by using homemade bolus with appropriate combination (filament density) of concave and convex parts of bolus comparative to the other methods. The aim of the research is to provide a better method for the treatment of the localized skin cancer of the size >4 cm.
Rajan Prajapati, Golam Abu Zakaria, Hasin Anupama Azhari