Article

Prostate Volume Measurement by TRUS Using Heights Obtained by Transaxial and Midsagittal Scaning: Comparison with Specimen Volume Following Radical Prostatectomy

Department of Radiology, University of Ulsan College of Medicine, Seoul, Korea.
Korean Journal of Radiology (Impact Factor: 1.81). 06/2000; 1(2):110-3. DOI: 10.3348/kjr.2000.1.2.110
Source: PubMed

ABSTRACT The purpose of this study was to determine, when measuring prostate volume by TRUS, whether height is more accurately determined by transaxial or midsagittal scanning.
Sixteen patients who between March 1995 and March 1998 underwent both preoperative TRUS and radical prostatectomy for prostate cancer were included in this study. Using prolate ellipse volume calculation (height x length x width x pi/6), TRUS prostate volume was determined, and was compared with the measured volume of the specimen.
Prostate volume measured by TRUS, regardless of whether height was determined transaxially or midsagittally, correlated closely with real specimen volume. When height was measured in one of these planes, a paired t test revealed no significant difference between TRUS prostate volume and real specimen volume (p =.411 and p =.740, respectively), nor were there significant differences between the findings of transaxial and midsagittal scanning (p =.570). A paired sample test, however, indicated that TRUS prostate volumes determined transaxially showed a higher correlation coefficient (0.833) and a lower standard deviation (9.04) than those determined midsagittally (0.714 and 11.48, respectively).
Prostate volume measured by TRUS closely correlates with real prostate volume. Furthermore, we suggest that when measuring prostate volume in this way, height is more accurately determined by transaxial than by midsagittal scanning.

Download full-text

Full-text

Available from: Sung Bin Park, Apr 07, 2015
0 Followers
 · 
85 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: "In this thesis, we propose a novel algorithm for detecting needles and their corresponding implanted radioactive seed locations in the prostate. The seed localization process is carried out efficiently using separable Gaussian filters in a probabilistic Gibbs random field framework. An approximation of the needle path through the prostate volume is obtained using a polynomial fit. The seeds are then detected and assigned to their corresponding needles by calculating local maxima of the voronoi region around the needle position. In our experiments, we were able to successfully localize over 85% of the implanted seeds. Furthermore, as a regular part of a brachytherapy cancer treatment, patient's prostate is scanned using a trans-rectal ultrasound probe, its boundary is manually outlined, and its volume is estimated for dosimetry purposes. In this thesis, we also propose a novel semi-automatic segmentation algorithm for prostate boundary detection that requires a reduced amount of radiologist's input, and thus speeds up the surgical procedure. Saved time can be used to re-scan the prostate during the operation and accordingly adjust the treatment plan. The proposed segmentation algorithm utilizes texture differences between ultrasound images of the prostate tissue and the surrounding tissues. It is carried out in the polar coordinate system and it uses three-dimensional data correlation to improve the smoothness and reliability of the segmentation. Test results show that the boundary segmentation obtained from the algorithm can reduce manual input by the factor of 3, without significantly affecting the accuracy of the segmentation (i.e. semi-automatically estimated prostate volume is within 90% of the original estimate)"--Abstract. Typescript. Thesis (M.S.)--Rochester Institute of Technology, 2006. Includes bibliographical references (leaves 48-51).
  • [Show abstract] [Hide abstract]
    ABSTRACT: A preliminary study to investigate the intra-observer and inter-observer variability of measurements of vestibular schwannoma volume using an area-tracing and linear dimension measurement method. Prospective blinded measurements by two observers (one a consultant and one a sub-specialty trainee in neuroradiology). Ambulatory patients with known vestibular schwannoma attending a tertiary referral centre. Participants: Twenty-three patients with 26 vestibular schwannomas aged 29-80 years old. Quantification of the variability in measured volume due to intra- and inter-observer measurement differences, expressed as reliability coefficients within which 95% of repeated measurements are calculated to lie from each other in relative percentage terms. For the linear measurement method, intraobserver variability was calculated to have a reliability coefficient of 65% and for interobserver variability this was 155%. For the area tracing method, the corresponding coefficients were 26% for intraobserver variability and 44% for interobserver variability. Volume measurements in vestibular schwannoma are variable even when the measurements are made by the same observer on identical images. The area tracing method, commonly regarded as the gold standard, is less variable than a linear method but still introduces more variability than commonly realized (for 95% of patients, repeated measurements by the same observer lie within around 25% of each other). Manual area tracing is not widely used in practice because it is time consuming and reliable automated methods are eagerly awaited.
    Clinical otolaryngology: official journal of ENT-UK; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery 05/2006; 31(2):123-9. DOI:10.1111/j.1749-4486.2006.01161.x · 2.27 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To compare the differences in prostate volume assessed by computerized tomography (CT), step-section transrectal ultrasound (TRUS-step), and TRUS with ellipsoid-formula volume calculation (TRUS-ellipsoid). Thirty-one patients with localized prostate cancer treated with combined external conformal radiotherapy and high dose rate brachytherapy, who had prostate volumes evaluated using CT, TRUS-step and TRUS-ellipsoid according to our clinical routine for dose planning. The measurements were collected retrospectively based on actual dose-plans. The prostate volume was on average 34 cc (range 18-60 cc) according to CT, 28 cc (range 12-57 cc) and 24 cc (range 13-44 cc) according to TRUS-step and TRUS-ellipsoid, respectively. The differences between the lengths measured were most pronounced with a mean length of 4.5 cm (range 3.0-6.0 cm) defined by CT as compared to 3.6 cm (range 3.0-5.0 cm) and 3.6 cm (range 2.8-5.0 cm) when defined by TRUS-step and TRUS-ellipsoid, respectively. CT defined volumes are 30% larger than volumes defined with TRUS-step. This is probably due to uncertainty in defining the apex of the prostate and thereby the length of the prostate using CT. When defining target in radiotherapy, it is important to be aware of the differences in volumes depending on the technique used.
    Radiotherapy and Oncology 12/2006; 81(2):179-83. DOI:10.1016/j.radonc.2006.10.003 · 4.86 Impact Factor
Show more