Bladder filling variation during radiation treatment of prostate cancer: can the use of a bladder ultrasound scanner and biofeedback optimize bladder filling?
OBJECTIVE
To investigate the use of a bladder ultrasound scanner in achieving a better reproducible bladder filling during irradiation of pelvic tumors, specifically prostate cancer.


METHODS
First, the accuracy of the bladder ultrasound scanner relative to computed tomography was validated in a group of 26 patients. Next, daily bladder volume variation was evaluated in a group of 18 patients. Another 16 patients participated in a biofeedback protocol, aiming at a more constant bladder volume. The last objective was to study correlations between prostate motion and bladder filling, by using electronic portal imaging device data on implanted gold markers.


RESULTS
A strong correlation between bladder scanner volume and computed tomography volume (r = 0.95) was found. Daily bladder volume variation was very high (1 SD = 47.2%). Bladder filling and daily variation did not significantly differ between the control and the feedback group (47.2% and 40.1%, respectively). Furthermore, no linear correlations between bladder volume variation and prostate motion were found.


CONCLUSIONS
This study shows large variations in daily bladder volume. The use of a biofeedback protocol yields little reduction in bladder volume variation. Even so, the bladder scanner is an easy to use and accurate tool to register these variations.
Stam
Marcel R
MR
Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. m.stam@rther.umcn.nl
van Lin
Emile N J Th
EN
van der Vight
Lisette P
LP
Kaanders
Johannes H A M
JH
Visser
Andries G
AG
D001676:Biofeedback, Psychology / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement; D011467:Prostate; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D014463:Ultrasonography; D001743:Urinary Bladder / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D016526:Workload