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A comparative assessment of prostate positioning guided by three-dimensional ultrasound and cone beam CT.

Li M, Ballhausen H, Hegemann NS, Ganswindt U, Manapov F, Tritschler S, Roosen A, Gratzke C, Reiner M, Belka C - Radiat Oncol (2015)

Bottom Line: Setup errors detected by the different modalities were compared.The discrepancy between 3DUS and seed-match in CBCT was -0.2 ± 2.7 mm laterally, -1.9 ± 2.3 mm longitudinally and 0.0 ± 3.0 mm vertically and significant only in longitudinal direction.Further study of 3DUS for image guidance in a large patient cohort is warranted.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, University Hospital Munich, Ludwig-Maximilians-University, Munich, Germany. minglun.li@med.uni-muenchen.de.

ABSTRACT

Background: The accuracy of the Elekta Clarity™ three-dimensional ultrasound system (3DUS) was assessed for prostate positioning and compared to seed- and bone-based positioning in kilo-voltage cone-beam computed tomography (CBCT) during a definitive radiotherapy.

Methods: The prostate positioning of 6 patients, with fiducial markers implanted into the prostate, was controlled by 3DUS and CBCT. In total, 78 ultrasound scans were performed trans-abdominally and compared to bone-matches and seed-matches in CBCT scans. Setup errors detected by the different modalities were compared. Systematic and random errors were analysed, and optimal setup margins were calculated.

Results: The discrepancy between 3DUS and seed-match in CBCT was -0.2 ± 2.7 mm laterally, -1.9 ± 2.3 mm longitudinally and 0.0 ± 3.0 mm vertically and significant only in longitudinal direction. Using seed-match as reference, systematic errors of 3DUS were 1.3 mm laterally, 0.8 mm longitudinally and 1.4 mm vertically, and random errors were 2.5 mm laterally, 2.3 mm longitudinally, and 2.7 mm vertically. No significant difference could be detected for 3DUS in comparison to bone-match in CBCT.

Conclusions: 3DUS is feasible for image guidance for patients with prostate cancer and appears comparable to CBCT based image guidance in the retrospective study. While 3DUS offers some distinct advantages such as no need of invasive fiducial implantation and avoidance of extra radiation, its disadvantages include the operator dependence of the technique and dependence on sufficient bladder filling. Further study of 3DUS for image guidance in a large patient cohort is warranted.

No MeSH data available.


Related in: MedlinePlus

Elekta Clarity™system for transabdominal 3D ultrasound: mobile bedside workstation (left), free-hand probe with infrared reflectors (middle), and ceiling-mounted stereoscopic infrared camera (right, two arrows).
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Fig1: Elekta Clarity™system for transabdominal 3D ultrasound: mobile bedside workstation (left), free-hand probe with infrared reflectors (middle), and ceiling-mounted stereoscopic infrared camera (right, two arrows).

Mentions: The 3DUS system consisted of two identical Clarity units, one in the room of planning CT, and one in the treatment room. Each Clarity unit consists of a mobile US work-station with touch-screen and a free-hand US probe with 8 infrared reflectors firmly installed on it (Figure 1). Two ceiling-mounted stereoscopic infrared cameras track the US probe and calculates the geometric positions of the scanned structures in US images. For scanning, the US probe was manually placed 5–10 cm supra-pubic on the abdomen with a moderate pressure for a good image quality. Then the US probe is swept from superior to inferior, without translatory movement of the probe, to scan the prostate and bladder from retropubic to the top of bladder. If necessary, the placing position of US probe on the abdomen was changed for a possible complete vision of the bladder and prostate. After that the US probe was removed from patient. Based upon the primary US data, its 3D imaging was secondarily generated and presented in the workstation.Figure 1


A comparative assessment of prostate positioning guided by three-dimensional ultrasound and cone beam CT.

Li M, Ballhausen H, Hegemann NS, Ganswindt U, Manapov F, Tritschler S, Roosen A, Gratzke C, Reiner M, Belka C - Radiat Oncol (2015)

Elekta Clarity™system for transabdominal 3D ultrasound: mobile bedside workstation (left), free-hand probe with infrared reflectors (middle), and ceiling-mounted stereoscopic infrared camera (right, two arrows).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4465303&req=5

Fig1: Elekta Clarity™system for transabdominal 3D ultrasound: mobile bedside workstation (left), free-hand probe with infrared reflectors (middle), and ceiling-mounted stereoscopic infrared camera (right, two arrows).
Mentions: The 3DUS system consisted of two identical Clarity units, one in the room of planning CT, and one in the treatment room. Each Clarity unit consists of a mobile US work-station with touch-screen and a free-hand US probe with 8 infrared reflectors firmly installed on it (Figure 1). Two ceiling-mounted stereoscopic infrared cameras track the US probe and calculates the geometric positions of the scanned structures in US images. For scanning, the US probe was manually placed 5–10 cm supra-pubic on the abdomen with a moderate pressure for a good image quality. Then the US probe is swept from superior to inferior, without translatory movement of the probe, to scan the prostate and bladder from retropubic to the top of bladder. If necessary, the placing position of US probe on the abdomen was changed for a possible complete vision of the bladder and prostate. After that the US probe was removed from patient. Based upon the primary US data, its 3D imaging was secondarily generated and presented in the workstation.Figure 1

Bottom Line: Setup errors detected by the different modalities were compared.The discrepancy between 3DUS and seed-match in CBCT was -0.2 ± 2.7 mm laterally, -1.9 ± 2.3 mm longitudinally and 0.0 ± 3.0 mm vertically and significant only in longitudinal direction.Further study of 3DUS for image guidance in a large patient cohort is warranted.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, University Hospital Munich, Ludwig-Maximilians-University, Munich, Germany. minglun.li@med.uni-muenchen.de.

ABSTRACT

Background: The accuracy of the Elekta Clarity™ three-dimensional ultrasound system (3DUS) was assessed for prostate positioning and compared to seed- and bone-based positioning in kilo-voltage cone-beam computed tomography (CBCT) during a definitive radiotherapy.

Methods: The prostate positioning of 6 patients, with fiducial markers implanted into the prostate, was controlled by 3DUS and CBCT. In total, 78 ultrasound scans were performed trans-abdominally and compared to bone-matches and seed-matches in CBCT scans. Setup errors detected by the different modalities were compared. Systematic and random errors were analysed, and optimal setup margins were calculated.

Results: The discrepancy between 3DUS and seed-match in CBCT was -0.2 ± 2.7 mm laterally, -1.9 ± 2.3 mm longitudinally and 0.0 ± 3.0 mm vertically and significant only in longitudinal direction. Using seed-match as reference, systematic errors of 3DUS were 1.3 mm laterally, 0.8 mm longitudinally and 1.4 mm vertically, and random errors were 2.5 mm laterally, 2.3 mm longitudinally, and 2.7 mm vertically. No significant difference could be detected for 3DUS in comparison to bone-match in CBCT.

Conclusions: 3DUS is feasible for image guidance for patients with prostate cancer and appears comparable to CBCT based image guidance in the retrospective study. While 3DUS offers some distinct advantages such as no need of invasive fiducial implantation and avoidance of extra radiation, its disadvantages include the operator dependence of the technique and dependence on sufficient bladder filling. Further study of 3DUS for image guidance in a large patient cohort is warranted.

No MeSH data available.


Related in: MedlinePlus