Interfractional variation in bladder volume and its impact on cervical cancer radiotherapy: Clinical significance of portable bladder scanner

Luo, Hong; Jin, Fang; Yang, Dan; Wang, Ying; Li, Chao; Guo, Mingfang; Ran, Xueqi; Liu, Xianfeng; Zhou, Qi; Wu, Yongzhong

doi:10.1118/1.4954206

Cited by 21 publications

(27 citation statements)

References 32 publications

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“…As for patients with a non-augmented bladder, the correlation coefficient for volumes measured using scanning and catheterization was 0.981 (P < 0.0001), which is higher than those of previous studies. [12][13] Therefore, our study showed that a bladder scanner offered an accurate and reliable alternative to catheterization for estimating bladder volume in patients with a relatively normal bladder shape, which is consistent with previous studies. 1,7,[8][9] What's more, in concordance with Al-Shaikh's findings, we concluded that the accuracy of urine volume measurement using ultrasonography is affected by bladder modality.…”

Section: Discussionsupporting

confidence: 91%

Effects of bladder shape on accuracy of measurement of bladder volume using portable ultrasound scanner and development of correction method

Zhao

Liu

Gao

et al. 2019

Neurourology and Urodynamics

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Aims To compare the accuracy of using a bladder scanner to measure bladder volume through intermittent catheterization (IC) in patients and to introduce the Bladder Deformation Index (BDI) to develop a correction method. Methods Bladder volume was assessed by a nurse with the scanner. A second nurse catheterized the patient's bladder. A third nurse measured the urine volume in a 500‐mL or 1000‐mL graduated cylinder. Results Sixty one patients were included and 590 pairs of data were obtained. The mean bladder volume measured using a scanner and IC was (332.3 ± 156.1) mL and (339.1 ± 158.8) mL. The mean absolute difference was 30.8 mL. The correlation coefficient was 0.929. Patients were classified into 2 groups depending on whether they had undergone augmentation cystoplasty. The mean absolute difference was 109.2 and 20.4 mL. The correlation coefficient was 0.712 and 0.981. According to the BDI, bladders can be classified into 3 groups. The mean absolute difference was 21.9, 60.4, and 109.4 mL. The correlation coefficient was 0.970, 0.839, and 0.783. The linear regression equations of Grade I and Grade II were Y = 1.11X + 3.1 and Y = 0.76X + 161.5. Conclusions The results showed that bladder shape plays a critical role in accuracy which is inversely associated with BDI. This degree of accuracy is sufficient; especially measurement adjusted using the linear regression equation in patients with high BDI. However, although the preliminary results of the study are promising, a large‐scale prospective study should be needed to address the validation of the data in the future.

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Section: Discussionsupporting

confidence: 91%

Effects of bladder shape on accuracy of measurement of bladder volume using portable ultrasound scanner and development of correction method

Zhao

Liu

Gao

et al. 2019

Neurourology and Urodynamics

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“…This instrument showed a high precision volume readout for standard bladder phantom and actual urine 15 . In this study, we used this US scanner to investigate the BV change and mean urinary inflow rate ( v tot ) in relation to age ( P age ), water consumption ( P wat ), and body mass index ( P bmi ).…”

Section: Discussionmentioning

confidence: 99%

“…James reported that all patients achieved clinically acceptable target coverage while maintaining organ-at-risk dose sparing after weekly re-planning 19 . Recently, Luo found that the mean BV during the course of RT was approximately equal to the initial BV with US-scanner assistance 15 .…”

Section: Discussionmentioning

confidence: 99%

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A parameterized model for mean urinary inflow rate and its preliminary application in radiotherapy for cervical cancer

Jin

Luo

Zhou

et al. 2017

Sci Rep

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Forty-nine patients with stage IIb cervical cancer were included to investigate the changes in bladder volume in response to different approaches to maintaining consistent bladder filling. The impacts of age (P age), water consumption (P wat), and body mass index (BMI, P bmi) on the mean urinary inflow rate (v tot) were analysed. The bladder volume (BV) increased linearly over time. A large variation in v tot among individuals was observed, ranging from 0.19 to 5.13 ml/min. The v tot was correlated with P age (R = −0.53, p = 0.01) and P wat (R = 0.84, p = 0.00), and no correlation between v tot and P bmi was found (p > 0.05). Therefore, v tot could be parameterized using two methods: multivariable linear regression and iterative fitting. There was no statistically significant difference between the two methods. The model accuracy was successfully assessed with several validation tests for patients with good compliance (79.2% of all patients), and the proportion of radiotherapy (RT) fractions with zero wait time (one ultrasound (US) scan) increased from 6.5% to 41.2%. The optimal US scanning number and RT time could be provided using this model. This adaptive RT approach could reduce patient discomfort caused by holding onto urine and reduce technician labour as well as cost.

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“…Some studies have reported that the variation in bladder volume can influence changes in target volume and irradiated dose during pelvic RT. [8,15,16] Consistent results of volume measurement are indispensable to ensure effective and safe advanced-RT techniques. Thus, many studies have investigated accurate and useful tools for the regular measurement of bladder volumes.…”

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confidence: 99%

Simple calculation using anatomical features on pre-treatment verification CT for bladder volume estimation during radiation therapy for rectal cancer

et al. 2020

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Background Despite detailed instruction for full bladder, patients are unable to maintain consistent bladder filling during a 5-week pelvic radiation therapy (RT) course. We investigated the best bladder volume estimation procedure for verifying consistent bladder volume. Methods We reviewed 462 patients who underwent pelvic RT. Biofeedback using a bladder scanner was conducted before simulation and during treatment. Exact bladder volume was calculated by bladder inner wall contour based on CT images (Vctsim). Bladder volume was estimated either by bladder scanner (Vscan) or anatomical features from the presacral promontory to the bladder base and dome in the sagittal plane of CT (Vratio). The feasibility of Vratio was validated using daily megavoltage or kV cone-beam CT before treatment. Results Mean Vctsim was 335.6 ± 147.5 cc. Despite a positive correlation between Vctsim and Vscan (R2 = 0.278) and between Vctsim and Vratio (R2 = 0.424), Vratio yielded more consistent results than Vscan, with a mean percentage error of 26.3 (SD 19.6, p < 0.001). The correlation between Vratio and Vctsim was stronger than that between Vscan and Vctsim (Z-score: − 7.782, p < 0.001). An accuracy of Vratio was consistent in megavoltage or kV cone-beam CT during treatment. In a representative case, we can dichotomize for clinical scenarios with or without bowel displacement, using a ratio of 0.8 resulting in significant changes in bowel volume exposed to low radiation doses. Conclusions Bladder volume estimation using personalized anatomical features based on pre-treatment verification CT images was useful and more accurate than physician-dependent bladder scanners. Trial registration Retrospectively registered.

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Interfractional variation in bladder volume and its impact on cervical cancer radiotherapy: Clinical significance of portable bladder scanner

Abstract: Changes in the BV have an influence on the RT of cervical cancer. A consistent and reproducible BV is acquired by using a portable BS, whereby the target displacement and CTV-to-PTV margin can be both reduced in the SI direction.

Cited by 21 publications

References 32 publications

Effects of bladder shape on accuracy of measurement of bladder volume using portable ultrasound scanner and development of correction method

Effects of bladder shape on accuracy of measurement of bladder volume using portable ultrasound scanner and development of correction method

A parameterized model for mean urinary inflow rate and its preliminary application in radiotherapy for cervical cancer

Simple calculation using anatomical features on pre-treatment verification CT for bladder volume estimation during radiation therapy for rectal cancer

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