Use of a prospective cohort study in the development of a bladder scanning protocol to assist in bladder filling consistency for prostate cancer patients receiving radiation therapy

• Published in: Journal of medical radiation sciences Vol. 63; no. 3; pp. 179 - 185
• Main Authors: Cramp, Leah, Connors, Vanessa, Wood, Maree, Westhuyzen, Justin, McKay, Michael, Greenham, Stuart
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.09.2016; John Wiley & Sons, Inc; John Wiley and Sons Inc
• Subjects: Aged; Bladder; Cancer therapies; Case-Control Studies; Cohort analysis; Cohort Studies; Diagnostic imaging; Feasibility studies; Health risk assessment; Humans; Male; Medical diagnosis; Medical records; Middle Aged; Original; Patients; Planning; Prospective Studies; prostate; Prostate cancer; Prostatic Neoplasms - diagnostic imaging; Prostatic Neoplasms - radiotherapy; Radiation therapy; radiotherapy; Radiotherapy, Intensity-Modulated - adverse effects; Scanners; Simulation; Ultrasonic imaging; ultrasonography; Ultrasonography - instrumentation; Ultrasonography - methods; urinary bladder; Urinary Bladder - diagnostic imaging; Urinary Bladder - radiation effects; radiotherapy; Diagnostic imaging; prostate; ultrasonography; urinary bladder
• ISSN: 2051-3895; 2051-3909
• DOI: 10.1002/jmrs.162

Introduction Evidence of variations in bladder filling effecting prostate stability and therefore treatment and side‐effects is well established with intensity modulated radiation therapy (IMRT). This study aimed to increase bladder volume reproducibility for prostate radiation therapy by implementing a bladder scanning (BS) protocol that could assist patients' bladder filling at computed tomography (CT) simulation and treatment. Methods Based on a retrospective review of 524 prostate cancer patients, a bladder volume of 250–350 mL was adopted as ‘ideal’ for achieving planning dose constraints. A prospective cohort study was conducted to assess the clinical utility of measuring patients' bladder volumes at CT simulation using an ultrasound bladder scanner (Verathon 9400 BladderScan®). A revised bladder preparation protocol was utilised by a bladder scan group (BS) and a non‐BS group followed the standard departmental bladder preparation protocol. Time and volume data for the BS group (n = 17) were compared with the non‐BS group (n = 17). Results The BS cohort had a CT bladder volume range of 221–588 mL; mean 379 mL, SD 125 mL. The non‐BS group had a larger range: 184–757 mL; mean 373 mL, SD 160 mL (P = 0.9171). There was a positive correlation between CT volume and BS volume in the BS group (r = 0.797; P = 0.0002) although BS volumes were smaller: range 160–420 mL; mean 251 mL; SD 91 mL; P < 0.0001). The maximum bladder volume receiving 50 Gy (V50) from the BS group was 46.4%, mean 24.5%. The maximum bladder V50 from the non‐BS group was 50.9%, mean 27.3% (P = 0.5178). Treatment data from weekly cone beam CT scans were also compared over 6 weeks. They were assessed as being a pass if bladder and bowel requirements were acceptable. The BS group proceeded to treatment on the basis of a pass 92.7% of the time, whereas the pass rate for non‐BS group was 75%; difference 17.7% (P < 0.0001). Conclusion The BS is a useful tool for achieving consistent, appropriately sized bladder volumes in prostate cancer patients. This study aimed to increase bladder filling reproducibility for prostate radiation therapy patients by implementing a method of assessing patients' bladder volume at computed tomography (CT) simulation, using an ultrasound bladder scanner (Verathon 9400 BladderScan). Results found that the routine use of the Bladder Scanner has increased scheduled treatment efficiency and potentially improved patient care.