Accuracy and repeatability of prostate volume measurements by transrectal ultrasound

Eri, Lars M.; Thomassen, H; Brennhovd, Bjørn; Håheim, Lise Lund

doi:10.1038/sj.pcan.4500568

Cited by 88 publications

(76 citation statements)

References 13 publications

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“…As demonstrated by Rodriguez et al ( 24 ), there commonly used ( 13,(15)(16)(17). While the ellipsoid formula is used as a practical clinical protocol for time-effi cient PV estimation, it can yield substantial inaccuracies with two-dimensional transrectal US ( 11,18 ).…”

Section: Reference Standardmentioning

confidence: 99%

Automated Computer-derived Prostate Volumes from MR Imaging Data: Comparison with Radiologist-derived MR Imaging and Pathologic Specimen Volumes

Bulman¹,

Tóth²,

Patel

et al. 2012

Radiology

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Purpose:To compare prostate gland volume (PV) estimation of automated computer-generated multifeature active shape models (MFAs) performed with 3-T magnetic resonance (MR) imaging with that of other methods of PV assessment, with pathologic specimens as the reference standard. Materials and Methods:All subjects provided written informed consent for this HIPAA-compliant and institutional review board-approved study. Freshly weighed prostatectomy specimens from 91 patients (mean age, 59 years; range, 42-84 years) served as the reference standard. PVs were manually calculated by two independent readers from MR images by using the standard ellipsoid formula. Planimetry PV was calculated from gland areas generated by two independent investigators by using manually drawn regions of interest.Computer-automated assessment of PV with an MFA was determined by the aggregate computer-calculated prostate area over the range of axial T2-weighted prostate MR images. Linear regression, linear mixed-effects models, concordance correlation coeffi cients, and Bland-Altman limits of agreement were used to compare volume estimation methods. Results:MFA-derived PVs had the best correlation with pathologic specimen PVs (slope, 0.888). Planimetry derived volumes produced slopes of 0.864 and 0.804 for two independent readers when compared with specimen PVs. Ellipsoid formula-derived PVs had slopes closest to one when compared with planimetry PVs. Manual MR imaging and MFA PV estimates had high concordance correlation coefficients with pathologic specimens. Conclusion:MFAs with axial T2-weighted MR imaging provided an automated and effi cient tool with which to assess PV. Both MFAs and MR imaging planimetry require adjustments for optimized PV accuracy when compared with prostatectomy specimens.q RSNA, 2012

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Section: Reference Standardmentioning

confidence: 99%

Automated Computer-derived Prostate Volumes from MR Imaging Data: Comparison with Radiologist-derived MR Imaging and Pathologic Specimen Volumes

Bulman¹,

Tóth²,

Patel

et al. 2012

Radiology

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“…The inferior–superior direction is indicated by letter Z. In the X‐Y plane, the resolutions of the fiducial marker center locations were generated according to the resolution of grid template, which is 5 mm, while interval along the Z direction was determined by the size of the fiducial markers and the average‐sized prostate 12, 13. Total of 40 different fiducial marker implant patterns for four fiducial marker combinations were studied.…”

Section: Methodsmentioning

confidence: 99%

Recommendation of fiducial marker implantation for better target tracking using MV imager in prostate radiotherapy

Kilian-Meneghin

Kumaraswamy

2018

J Applied Clin Med Phys

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PurposeThe aim of this study was to develop a model that optimizes the fiducial marker locations in the prostate to increase detectability of the markers in the projected EPID images during VMAT treatments.Methods and MaterialsThe fiducial marker tracking capability for each arc was evaluated through a proposed formula. The output of the formula, a detectability score, was calculated with the in‐house developed software written in MATLAB (The Mathworks, Inc., Natick, MA, USA). Three unique weighting factors were added to penalize the detectability score. The detectability scores of four different patterns containing 40 combinations of simulated fiducial marker locations were evaluated with 101 previously treated prostate treatment plans (containing 202 individual arcs). The results were analyzed for each pattern group and each marker separation distance on the transverse plane.ResultsThe maximum detectability of the markers occurred when they were placed between 10 and 15 mm from the center of the prostate in the transverse plane and 6–13 mm in the superior–inferior direction. The detectability decreased when the markers were placed beyond 20 mm in both directions.ConclusionsThe fiducial marker‐based detectability score can be used to predict the real‐time tracking capability. Suggestions for optimal insertion locations were given to improve prostate motion management using MV imaging.

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“…Theoretically the volume is calculated by prolate ellipsoidal size formula [17] .The volume of the prostate was calculated by using TRUS. The height of the prostate is more precisely determined by using transaxial than mid sagittal scanning [18].Simple formula determined prostate volume (Prolate ellipsoid & prolate spheroid), based on prostate diameters, the results provide only marginally inferior to planimetry, which are preferable because they are simpler to perform in the clinic and are associated with less inconvenience for patient [11].…”

Section: Volume Of Prostatementioning

confidence: 99%

“…The electronic stopping powers were calculated by using Bethe-Bloch model, which have showed good agreement with the TRIM results with 0.99 correlation factor. Many studies were done for calculating the volume of prostate, some of them show that, the common shapes of human prostate are: prolate ellipsoid or prolate spheroid [11] Objective…”

Section: Notably Light (Linac For Image Guided Hadrons Therapy) Is Dmentioning

confidence: 99%

Theoretical Analysis of Proton Therapy for Prostate Cancer

Ibrahim¹

2017

DJPS

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The dependence of high proton energies has been investigated for proton therapy, which are governed by essential physical factors such as ion ranges and stopping powers. In addition, the volume of prostate is another variable factor varies according to human age and types of tumor.The aim of this theoretical study is about bombardment the prostate tumor by normal incidence protons from Medical Cyclotron at room temperature and energy ranges 60-250 MeV. It was studied by means of calculating Stopping Powers, 3D Ion ranges (longitudinal, lateral and radial) and the total target damage as a function of proton energies, which are calculated by TRIM computer code. The electronic stopping powers were calculated by Bethe-Bloch model, which have showed good coincidence with the TRIM results with 0.99 correlation factor. The ionization process is predominated through track of protons in tissues of the prostate, which yields a steep increase in total stopping power with penetration distance leading to the Bragg peak close to the end of range of the proton beams. The skewness and kurtosis are calculated, the negative sign of skewness for all spectra indicated that left tail (towards the surface of incidence protons) is larger than right (away from the surface) leading to reduce side effects to the neighboring normal tissues. The positive value of kurtosis means that the spectra are peaked.This indicates that the precise dose localization is delivered to the tissues. Proton therapy offers the benefit of specified dose localization and has favorable dose-depth distributions, compared with photon beam radiotherapy. The angular distribution of protons with different energies are studied to reach the tumor in any position in prostate, it is noticed that at angle of 45 degree, there is equidimensional ion ranges. The total target damage increases with proton energies with values (0.58 -1.7) KeV/ion for ranges energy (60 -250) MeV respectively. In order to reach the tumor, the proton beam direction could be changed in definite steps or turned on and off very quickly.Volumes of the different shapes of prostates change according to age and kinds of the tumor, which are prolate ellipsoid, prolate spheroid, or spherical shape. This leads to select the precise proton energy to prevent the spread of radiation outside the prostate.This theoretical study can be considered as a tool and an indication to determine the precise proton energy required for prostate cancer treatment to minimize the side effects. Proton therapy is a promising technology as a result of the rapid development of nuclear accelerators.

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Accuracy and repeatability of prostate volume measurements by transrectal ultrasound

Cited by 88 publications

References 13 publications

Automated Computer-derived Prostate Volumes from MR Imaging Data: Comparison with Radiologist-derived MR Imaging and Pathologic Specimen Volumes

Automated Computer-derived Prostate Volumes from MR Imaging Data: Comparison with Radiologist-derived MR Imaging and Pathologic Specimen Volumes

Recommendation of fiducial marker implantation for better target tracking using MV imager in prostate radiotherapy

Theoretical Analysis of Proton Therapy for Prostate Cancer

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