Efficacy of Portable Bladder Ultrasound in Reducing CBCT Frequency During Pelvic Radiotherapy

OBJECTIVE
The aim of this study was to investigate the effect of the use of bladder ultrasonography (USG) on time and workforce efficiency in patients with prostate, bladder, cervix, endometrium and rectal cancer undergoing curative pelvic radiotherapy (RT) in a radiation oncology clinic.
METHODS
The study included 142 patients who underwent pelvic RT. The prospective study group (n=71) underwent bladder USG, while the other patients included in the study (n=71) who received standard treatment were designated as the retrospective historical control group. All patients underwent planning tomography (CT), set-up verification was performed with cone beam computed tomography (CBCT) in the first 3 fractions and then evaluated with CBCT once a week. All analyses were performed using IBM SPSS Statistics Version 25 package program. A value of P<0.05 was determined as the significance level.
RESULTS
Patients who did not undergo USG underwent 846 CBCTs and patients who underwent USG underwent 809 CBCTs. Although not significant, fewer CBCTs were performed in the USG group. When patients with prostate cancer were analyzed; 37 patients with prostate cancer who did not undergo USG had a total of 476 CBCTs at the end of treatment. In 37 patients with prostate cancer who underwent USG, a total of 427 CBCTs were performed. The difference between these two groups was statistically significant (p=0.009).
CONCLUSION
In patients undergoing pelvic RT, both pre-planning CT and pre-treatment USG were used to determine bladder fullness.

Keywords: Cone beam computed tomography; pelvic neoplasms; radiotherapy; urinary bladder; ultrasonography.