Open AccessUse 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
Author(s) -
Cramp Leah,
Connors Vanessa,
Wood Maree,
Westhuyzen Justin,
McKay Michael,
Greenham Stuart
Publication year - 2016
Publication title -
journal of medical radiation sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 18
eISSN - 2051-3909
pISSN - 2051-3895
DOI - 10.1002/jmrs.162
Subject(s) - medicine , urology , prostate , bladder cancer , prostate cancer , radiation therapy , prospective cohort study , nuclear medicine , reproducibility , radiology , surgery , cancer , statistics , mathematics
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.