Limits...
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

View Article: PubMed Central - PubMed

ABSTRACT

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.

No MeSH data available.


Bladder volumes outlined in the focal system exceeding the V50 < 50 Gy planning dose constraint.7 (V50 < 50 Gy: 50% of bladder volume to receive < 50 Gy).
© Copyright Policy - creativeCommonsBy-nc-nd
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5016618&req=5

jmrs162-fig-0001: Bladder volumes outlined in the focal system exceeding the V50 < 50 Gy planning dose constraint.7 (V50 < 50 Gy: 50% of bladder volume to receive < 50 Gy).

Mentions: In order to determine an appropriate bladder volume range that would satisfy planning constraints, 524 bladder volumes were retrospectively analysed from prostate planning assessment data in our electronic medical record system (Mosaiq™, Elekta Pty Ltd., North Sydney, Australia) collected across three departments between November 2008 and November 2011. Bladder volumes ranged from 41 mL to 1526 mL, with a mean volume of 321 mL (SD 190 mL). An analysis of the bladder volume versus the number of patients exceeding the V50 < 50 Gy bladder planning constraint8 used in our institute showed an inverse relationship with larger bladder volumes increasingly meeting treatment criteria (Fig. 1). With a target bladder volume of 250–350 mL, the chances of exceeding the V50 < 50 Gy bladder constraint was <5%. Based on these observations this was selected as the target bladder volume range for subsequent work in evaluating and developing the protocol for use of the bladder scanner.


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
Bladder volumes outlined in the focal system exceeding the V50 < 50 Gy planning dose constraint.7 (V50 < 50 Gy: 50% of bladder volume to receive < 50 Gy).
© Copyright Policy - creativeCommonsBy-nc-nd
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5016618&req=5

jmrs162-fig-0001: Bladder volumes outlined in the focal system exceeding the V50 < 50 Gy planning dose constraint.7 (V50 < 50 Gy: 50% of bladder volume to receive < 50 Gy).
Mentions: In order to determine an appropriate bladder volume range that would satisfy planning constraints, 524 bladder volumes were retrospectively analysed from prostate planning assessment data in our electronic medical record system (Mosaiq™, Elekta Pty Ltd., North Sydney, Australia) collected across three departments between November 2008 and November 2011. Bladder volumes ranged from 41 mL to 1526 mL, with a mean volume of 321 mL (SD 190 mL). An analysis of the bladder volume versus the number of patients exceeding the V50 < 50 Gy bladder planning constraint8 used in our institute showed an inverse relationship with larger bladder volumes increasingly meeting treatment criteria (Fig. 1). With a target bladder volume of 250–350 mL, the chances of exceeding the V50 < 50 Gy bladder constraint was <5%. Based on these observations this was selected as the target bladder volume range for subsequent work in evaluating and developing the protocol for use of the bladder scanner.

View Article: PubMed Central - PubMed

ABSTRACT

Introduction: Evidence of variations in bladder filling effecting prostate stability and therefore treatment and side&#8208;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&ndash;350 mL was adopted as &lsquo;ideal&rsquo; 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&reg;). A revised bladder preparation protocol was utilised by a bladder scan group (BS) and a non&#8208;BS group followed the standard departmental bladder preparation protocol. Time and volume data for the BS group (n = 17) were compared with the non&#8208;BS group (n = 17).

Results: The BS cohort had a CT bladder volume range of 221&ndash;588 mL; mean 379 mL, SD 125 mL. The non&#8208;BS group had a larger range: 184&ndash;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&ndash;420 mL; mean 251 mL; SD 91 mL; P &lt; 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&#8208;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&#8208;BS group was 75%; difference 17.7% (P &lt; 0.0001).

Conclusion: The BS is a useful tool for achieving consistent, appropriately sized bladder volumes in prostate cancer patients.

No MeSH data available.