Comparison of Prostate Volume Measured by Endorectal Coil MRI to Prostate Specimen Volume and Mass After Radical Prostatectomy

Mazaheri, Yousef; Goldman, Debra A.; Paolo, Pier Luigi Di; Akın, Oğuz; Hricak, Hedvig

doi:10.1016/j.acra.2015.01.003

Cited by 23 publications

(27 citation statements)

References 30 publications

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“…Since the specific gravity of prostate tissue and water are nearly identical (1.05 gm to 1.0 ml) 13 , weight and volume have traditionally been used interchangeably in the literature, introducing mild inaccuracies when comparing image volumes to pathologic weights in larger glands. Some investigators use this number as a correction factor for comparing weight to volume 9,46 . This assumption fails to take into account that it is likely that there is a spectrum of density values in larger prostates with different proportions of stromal, glandular, and malignant tissues 13 .…”

Section: Discussionmentioning

confidence: 99%

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy

Wasserman

Niendorf

Spilseth

2020

Sci Rep

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To review the anatomic basis of prostate boundary selection on T2-weighted magnetic resonance imaging (MRI). To introduce an alternative 3D ellipsoid measuring technique that maximizes precision, report the intra-and inter-observer reliability, and to advocate it's use for research involving multiple observers. We demonstrate prostate boundary anatomy using gross pathology and MRI examples. This provides background for selecting key boundary marks when measuring prostate volume. An alternative ellipsoid volume method is then proposed using these boundaries in an attempt to improve inter-observer precision. An IRB approved retrospective study of 140 patients with elevated serum prostate specific antigen levels and/or abnormal digital rectal examinations was done with T2-weighted MRI applying a new (Biproximate) technique. Measurements were made by 2 examiners, correlated with each other for inter-observer precision and correlated with an expert observer for accuracy. Correlation statistics, linear regression analysis, and tests of means were applied using p ≤ 0.05 as the threshold for significance. Inter-observer correlation (precision) was 0.95 between observers. Correlation between these observers and the expert (accuracy) was 0.94 and 0.97 respectively. Intraobserver correlation for the expert was 0.98. Means for inter-rater reliability and accuracy were all the same (p = 0.001). We conclude that using more precise reproducible landmarks with biproximate technique, precision and accuracy of total prostate volume is found to be demonstrated.

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Section: Discussionmentioning

confidence: 99%

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy

Wasserman

Niendorf

Spilseth

2020

Sci Rep

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“…Since the specific gravity of prostate tissue and water are nearly identical (1.05 gm to 1.0 ml) [46], weight and volume have traditionally been used interchangeably in the literature, introducing mild inaccuracies when comparing image volumes to pathologic weights in larger glands. Some investigators use this number as a correction factor for comparing weight to volume [9,47]. This assumption fails to take into account that it is likely that there is a spectrum of density values in larger prostates with different proportions of stromal, glandular, and malignant tissues [46].…”

Section: Discussionmentioning

confidence: 99%

“…The specimen may include the attached seminal vesicles, vas deferens and surrounding soft tissues in many studies [48]. In some, the seminal vesicles and vas deferens are physically removed before weighing [49,14,9], and in others the estimated mean volume of the seminal vesicles, as determined from the medical literature, is subtracted from the total weight of the prostate and accessory structures [15,47]. Changes in prostate size due to drying or fixation complicate comparisons in cadaver studies [49,50].…”

Section: Discussionmentioning

confidence: 99%

“…The former requires significant boundary adjustments by an expert reader who still must ultimately understand the anatomy and landmarks we have described. At present, these techniques are thought by most to be too labor intensive for speedy clinical use [9, 47,51]. Fully automatic unsupervised computerized assisted programs are under study, but performance compared with simpler methods is less well understood [44].…”

Section: Discussionmentioning

confidence: 99%

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Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy

Wasserman

Niendorf

Spilseth

2019

Preprint

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Purpose: To review the anatomic basis of prostate boundary selection on T2weighted magnetic resonance imaging (MRI). To introduce an alternative 3D ellipsoid measuring technique that maximizes precision, report the intra-and inter-observer reliability, and to advocate it's use for research involving multiple observers.Methods: A demonstration of prostate boundary anatomy using gross pathology and MRI examples provides background for selection of key boundary marks when measuring prostate volume. An alternative ellipsoid volume method is illustrated. An IRB approved retrospective study of 140 patients with elevated serum prostate specific antigen levels and/or abnormal digital rectal examinations was done with T2weighted MRI applying the new (Biproximate) technique. Measurements were made by 2 examiners, correlated with each other for interobserver precision and with an expert observer for accuracy. Correlation statistics, linear regression analysis, and tests of means were applied using p≤0.05 as the threshold for significance.Results: Inter-observer correlation (precision) was 0.95 between observers.Correlation between these observers and the expert (accuracy) was 0.94 and 0.97 respectively. Intra-observer correlation for the expert was 0.98. Means for inter-rater reliability and accuracy were all the same (p=0.001).Conclusions: Anatomic foundations for the boundaries of the prostate are reviewed.Precision and accuracy of total prostate volume using an alternative method is reported and found to be reproducible.TRUS overestimates post-operative small specimen size and underestimates large prostates [15,16]. However other investigators using MRI EVF volumetrics report overestimation compared to specimen volume (corrected for density of 1.05 gm/cc) [9].There are scant studies of inter-observer reliability for the measurement of total prostatic volume using standard methods [10,11,17]. TRUS intra-rater reliability using the ellipsoid formula was examined in one study and was 0.93 [12]. Bangma, et al. [18] compared TRUS step-section planigraphy with several geometric multiplane models and found the prolate ellipsoid to be comparable (r=0.89). Early application of MRI using the EVF showed acceptable precision and accuracy in one small study [6].The purpose of this study is three-fold. We review detailed anatomy required to more confidently find measurement boundaries. We introduce a new multiplane EVF approach to make these measurements using MRI, and report results of inter-rater and intrarater reliability with this technique. Materials and Methods Patient Selection"This study was approved by our institutional Internal Review Board and Ethics Committee (protocol number 00003941) with a waiver of informed consent". 140 patients were selected from a population of men undergoing MRI because of abnormal PSA, digital rectal examination or both. Ages ranged from 41-76 (mean, 64 years). They were selected by the senior radiologist (NFW) with over 40 years of experience who acted as administrator/expert. All MRI lobar cl...

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“…Although widely used, there is little data on its accuracy. In endorectal coil MRI, both at 1.5-and 3-Tesla, it has been shown that the ellipsoid formula gives good estimates of prostate volume [6,7] . Yet with the availability of surface coils for 3-Tesla MRI with their higher patient acceptance, there is a need to re-address this issue, especially since the prostate gland is no longer indented by an endorectal device having a different shape compared to endorectal ultrasound or MRI.…”

Section: Introductionmentioning

confidence: 99%

Is the Ellipsoid Formula the New Standard for 3-Tesla MRI Prostate Volume Calculation without Endorectal Coil?

Haas

Günzel²,

Miller³

et al. 2016

Urol Int

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Prostate volume in multiparametric MRI (mpMRI) is of clinical importance. For 3-Tesla mpMRI without endorectal coil, there is no distinctive standard for volume calculation. We tested the accuracy of the ellipsoid formula with planimetric volume measurements as reference and investigated the correlation of gland volume and cancer detection rate on MRI/ultrasound (MRI/US) fusion-guided biopsy. One hundred forty-three patients with findings on 3-Tesla mpMRI suspicious of cancer and subsequent MRI/US fusion-guided targeted biopsy and additional systematic biopsy were analyzed. T2-weighted images were used for measuring the prostate diameters and for planimetric volume measurement by a segmentation software. Planimetric and calculated prostate volumes were compared with clinical data. The median prostate volume was 48.1 ml (interquartile range (IQR) 36.9-62.1 ml). Volume calculated by the ellipsoid formula showed a strong concordance with planimetric volume, with a tendency to underestimate prostate volume (median volume 43.1 ml (IQR 31.2-58.8 ml); r = 0.903, p < 0.001). There was a moderate, significant inverse correlation of prostate volume to a positive biopsy result (r = -0.24, p = 0.004). The ellipsoid formula gives sufficient approximation of prostate volume on 3-Tesla mpMRI without endorectal coil. It allows a fast, valid volume calculation in prostate MRI datasets.

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Comparison of Prostate Volume Measured by Endorectal Coil MRI to Prostate Specimen Volume and Mass After Radical Prostatectomy

Cited by 23 publications

References 30 publications

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy

Is the Ellipsoid Formula the New Standard for 3-Tesla MRI Prostate Volume Calculation without Endorectal Coil?

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