Superior target volume and organ stability with the use of endorectal balloons in post‐prostatectomy radiotherapy

Introduction We investigated the endorectal balloon ( ERB ) as a method to improve post‐prostatectomy clinical target volume ( CTV ) stability. Methods Seventy cone‐beam CT ( CBCT ) obtained during radiotherapy treatment from seven patients treated with an ERB and 68 CBCT from seven patients treated without an ERB were contoured according to published guidelines. CTV was subdivided into superior and inferior CTV ; whole rectal volume was...