Contact Radiotherapy with a Rectal Brachytherapy Applicator Using 192Ir HDR Sources

Abstract

Radiation boost increases complete response rates for rectal tumors, potentially enabling the omission of surgery. Endoluminal boosting techniques such as 50 kV contact x-ray radiotherapy (CXRT) have the advantage of better targeting small volumes than external beam radiotherapy due to more accurate positioning of the applicator and steeper dose falloff, allowing organ preservation and better toxicity profiles. The widespread use of CXRT devices is restricted due to its high cost and lack of treatment planning tools. Hence, a cost-effective solution was developed by designing a rectal brachytherapy applicator that uses commonly available 192Ir HDR brachytherapy sources to generate dose distributions similar to those generated by CXRT devices. This offers the possibility of integration with currently available treatment planning systems (TPS).