Organ Movements and Dose Exposures in Teletherapy of Prostate Cancer using a Rectal Balloon

Abstract

The application of a rectal balloon in teletherapy of localized prostate cancer leads to significantly changed dose exposition of organs at risk. The decreased dose exposure of the posterior rectal wall and the rectal mucosa is opposed by the higher organ dose of the anterior rectal wall. It has to be shown weather documented organ dose exposure is associated with short and long-term consequences.

Reduced rectal toxicity with ultrasound-based image guided radiotherapy using BAT™ (B-mode acquisition and targeting system) for prostate cancer

“…Image guidance corrects this systematic difference between planned and treated rectum DVH while not changing dose to the tumor, thus reducing rectal toxicity but not further improving PSA control. Especially dose to the posterior rectal wall is reduced, which is similarly reported when endorectal balloons are used [6,7]. Wertz et al analyzed in a theoretic model the dosimetric consequences of positioning correction with BAT.…”

A strategy for the use of image-guided radiotherapy (IGRT) on linear accelerators and its impact on treatment margins for prostate cancer patients

“…To compensate for that in terms of further PTV reduction, methods of daily tracking of the prostate's position prior to treatment by sonography [11] and gold seed markers [15,21,22,25,26] have been investigated. Another attempt is to immobilize the prostate during treatment by rectal balloons [4].…”

Can the Rectum Balloon Minimize Rectal Toxicity During Irradiation Therapy of Prostate Cancer?

“…Besides stu lloon a dose reduction at the posterior rectum wall is opposed to a higher dose fraction at the anterior rectum wall [38].…”