TY  - JOUR
A1  - Diamantopoulos, Stefanos
A1  - Milickovic, Natasa
A1  - Butt, Saeed
A1  - Katsilieri, Zaira
A1  - Kefala, Vasiliki
A1  - Zogal, Pawel
A1  - Sakas, George
A1  - Baltas, Dimos
T1  - Effect of using different U/S probe Standoff materials in image geometry for interventional procedures : the example of prostate
T2  - Journal of contemporary brachytherapy
N2  - PURPOSE: This study investigates the distortion of geometry of catheters and anatomy in acquired U/S images, caused by utilizing various stand-off materials for covering a transrectal bi-planar ultrasound probe in HDR and LDR prostate brachytherapy, biopsy and other interventional procedures. Furthermore, an evaluation of currently established water-bath based quality assurance (QA) procedures is presented.
MATERIAL AND METHODS: Image acquisitions of an ultrasound QA setup were carried out at 5 MHz and 7 MHz. The U/S probe was covered by EA 4015 Silicone Standoff kit, or UA0059 Endocavity balloon filled either with water or one of the following: 40 ml of Endosgel(®), Instillagel(®), Ultraschall gel or Space OAR™ gel. The differences between images were recorded. Consequently, the dosimetric impact of the observed image distortion was investigated, using a tissue equivalent ultrasound prostate phantom - Model number 053 (CIRS Inc., Norfolk, VA, USA).
RESULTS: By using the EA 4015 Silicone Standoff kit in normal water with sound speed of 1525 m/s, a 3 mm needle shift was observed. The expansion of objects appeared in radial direction. The shift deforms also the PTV (prostate in our case) and other organs at risk (OARs) in the same way leading to overestimation of volume and underestimation of the dose. On the other hand, Instillagel(®) and Space OAR™ "shrinks" objects in an ultrasound image for 0.65 mm and 0.40 mm, respectively.
CONCLUSIONS: The use of EA 4015 Silicone Standoff kit for image acquisition, leads to erroneous contouring of PTV and OARs and reconstruction and placement of catheters, which results to incorrect dose calculation during prostate brachytherapy. Moreover, the reliability of QA procedures lies mostly in the right temperature of the water used for accurate simulation of real conditions of transrectal ultrasound imaging.
KW  - ultrasound
KW  - needle displacement
KW  - image distortion
KW  - prostate brachytherapy
Y1  - 2011
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/31716
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-317169
SN  - 2081-2841
SN  - 1689-832X
N1  - Copyright © 2011 Termedia This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License, permitting all non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
VL  - 3
IS  - 4
SP  - 209
EP  - 219
PB  - Termedia
CY  - Poznan
ER  -