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Performance and suitability assessment of a real-time 3D electromagnetic needle tracking system for interstitial brachytherapy.

Boutaleb S, Racine E, Fillion O, Bonillas A, Hautvast G, Binnekamp D, Beaulieu L - J Contemp Brachytherapy (2015)

Bottom Line: Position errors of less than 1 mm were recorded with all components except with a metallic arm support, which induced a mean absolute error of approximately 1.4 mm when located 10 cm away from the needle sensor.The Aurora(®) V1 PFG EMTS possesses a great potential for real-time treatment assistance in general interstitial brachytherapy.In view of our experimental results, we however recommend that the needle axis remains as parallel as possible to the generator surface during treatment and that the tracking zone be restricted to the first 30 cm from the generator surface.

View Article: PubMed Central - PubMed

Affiliation: Département de Radio-Oncologie et Centre de Recherche du CHU de Québec, Québec, Canada ; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Canada.

ABSTRACT

Purpose: Accurate insertion and overall needle positioning are key requirements for effective brachytherapy treatments. This work aims at demonstrating the accuracy performance and the suitability of the Aurora(®) V1 Planar Field Generator (PFG) electromagnetic tracking system (EMTS) for real-time treatment assistance in interstitial brachytherapy procedures.

Material and methods: The system's performance was characterized in two distinct studies. First, in an environment free of EM disturbance, the boundaries of the detection volume of the EMTS were characterized and a tracking error analysis was performed. Secondly, a distortion analysis was conducted as a means of assessing the tracking accuracy performance of the system in the presence of potential EM disturbance generated by the proximity of standard brachytherapy components.

Results: The tracking accuracy experiments showed that positional errors were typically 2 ± 1 mm in a zone restricted to the first 30 cm of the detection volume. However, at the edges of the detection volume, sensor position errors of up to 16 mm were recorded. On the other hand, orientation errors remained low at ± 2° for most of the measurements. The EM distortion analysis showed that the presence of typical brachytherapy components in vicinity of the EMTS had little influence on tracking accuracy. Position errors of less than 1 mm were recorded with all components except with a metallic arm support, which induced a mean absolute error of approximately 1.4 mm when located 10 cm away from the needle sensor.

Conclusions: The Aurora(®) V1 PFG EMTS possesses a great potential for real-time treatment assistance in general interstitial brachytherapy. In view of our experimental results, we however recommend that the needle axis remains as parallel as possible to the generator surface during treatment and that the tracking zone be restricted to the first 30 cm from the generator surface.

No MeSH data available.


Related in: MedlinePlus

Publications report using polycarbonate support used in the orientation accuracy analysis. The support contains machined holes with predefined orientations (± 1°)
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Figure 0004: Publications report using polycarbonate support used in the orientation accuracy analysis. The support contains machined holes with predefined orientations (± 1°)

Mentions: The orientation error analysis was performed from three distinct experiments. First, an analysis was performed from the measurements used in the position error analysis (since orientation was also recorded). In this case, the needle was held perpendicularly to the generator surface and measurements were taken as described in the previous paragraph. The tracking angle about the y axis (Qy) was recorded and compared to its ideal nil value. Secondly, orientations errors were characterized for three specific needle configurations with respect to the field generator surface: Perpendicular (0°), parallel + (+90°), and parallel (–90°) (Figure 3B). These angles are measured in the yz plane of the system with respect to the generator surface. In this experiment, measurements were taken at every tracking displacement of 25 mm along the z axis of the generator from z = –50 mm to z = –575 mm (with x = y = 0). Finally, orientation error measurements were made with a specially machined PMMA support, which allowed to impose up to 10 predefined needle orientations (Figure 4). The measurements were taken with the needle located at z = –55 mm on the system's central axis.


Performance and suitability assessment of a real-time 3D electromagnetic needle tracking system for interstitial brachytherapy.

Boutaleb S, Racine E, Fillion O, Bonillas A, Hautvast G, Binnekamp D, Beaulieu L - J Contemp Brachytherapy (2015)

Publications report using polycarbonate support used in the orientation accuracy analysis. The support contains machined holes with predefined orientations (± 1°)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643737&req=5

Figure 0004: Publications report using polycarbonate support used in the orientation accuracy analysis. The support contains machined holes with predefined orientations (± 1°)
Mentions: The orientation error analysis was performed from three distinct experiments. First, an analysis was performed from the measurements used in the position error analysis (since orientation was also recorded). In this case, the needle was held perpendicularly to the generator surface and measurements were taken as described in the previous paragraph. The tracking angle about the y axis (Qy) was recorded and compared to its ideal nil value. Secondly, orientations errors were characterized for three specific needle configurations with respect to the field generator surface: Perpendicular (0°), parallel + (+90°), and parallel (–90°) (Figure 3B). These angles are measured in the yz plane of the system with respect to the generator surface. In this experiment, measurements were taken at every tracking displacement of 25 mm along the z axis of the generator from z = –50 mm to z = –575 mm (with x = y = 0). Finally, orientation error measurements were made with a specially machined PMMA support, which allowed to impose up to 10 predefined needle orientations (Figure 4). The measurements were taken with the needle located at z = –55 mm on the system's central axis.

Bottom Line: Position errors of less than 1 mm were recorded with all components except with a metallic arm support, which induced a mean absolute error of approximately 1.4 mm when located 10 cm away from the needle sensor.The Aurora(®) V1 PFG EMTS possesses a great potential for real-time treatment assistance in general interstitial brachytherapy.In view of our experimental results, we however recommend that the needle axis remains as parallel as possible to the generator surface during treatment and that the tracking zone be restricted to the first 30 cm from the generator surface.

View Article: PubMed Central - PubMed

Affiliation: Département de Radio-Oncologie et Centre de Recherche du CHU de Québec, Québec, Canada ; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, Canada.

ABSTRACT

Purpose: Accurate insertion and overall needle positioning are key requirements for effective brachytherapy treatments. This work aims at demonstrating the accuracy performance and the suitability of the Aurora(®) V1 Planar Field Generator (PFG) electromagnetic tracking system (EMTS) for real-time treatment assistance in interstitial brachytherapy procedures.

Material and methods: The system's performance was characterized in two distinct studies. First, in an environment free of EM disturbance, the boundaries of the detection volume of the EMTS were characterized and a tracking error analysis was performed. Secondly, a distortion analysis was conducted as a means of assessing the tracking accuracy performance of the system in the presence of potential EM disturbance generated by the proximity of standard brachytherapy components.

Results: The tracking accuracy experiments showed that positional errors were typically 2 ± 1 mm in a zone restricted to the first 30 cm of the detection volume. However, at the edges of the detection volume, sensor position errors of up to 16 mm were recorded. On the other hand, orientation errors remained low at ± 2° for most of the measurements. The EM distortion analysis showed that the presence of typical brachytherapy components in vicinity of the EMTS had little influence on tracking accuracy. Position errors of less than 1 mm were recorded with all components except with a metallic arm support, which induced a mean absolute error of approximately 1.4 mm when located 10 cm away from the needle sensor.

Conclusions: The Aurora(®) V1 PFG EMTS possesses a great potential for real-time treatment assistance in general interstitial brachytherapy. In view of our experimental results, we however recommend that the needle axis remains as parallel as possible to the generator surface during treatment and that the tracking zone be restricted to the first 30 cm from the generator surface.

No MeSH data available.


Related in: MedlinePlus