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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

Histograms of absolute positional errors recorded throughout the specified tracking volume of the Aurora® V1 PFG. A) First half (z ∈[–300,–50] mm). B) Second half (z ∈[–550,–300] mm)
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Figure 0007: Histograms of absolute positional errors recorded throughout the specified tracking volume of the Aurora® V1 PFG. A) First half (z ∈[–300,–50] mm). B) Second half (z ∈[–550,–300] mm)

Mentions: The graphs of Figure 6 offer a qualitative appreciation of the measured positional errors of the EMTS at different distances from the PFG. They were however only obtained from a small subset of the 486 measurements made throughout the detection volume. Figure 7 displays histograms of absolute positional errors (3D) for all data points but located in the specified tracking volume of the Aurora® V1 PFG (a cube of 500 × 500 × 500 mm3). Errors associated with the first and second halves of the volume are presented. It can be seen that significantly lower positional errors are measured in the first half of the volume. Mean positional errors are respectively 3.4 mm for the first half, and 26 mm for the second one. The largest errors measured in the second half occur at the farthest distances (z = –550 mm) of the PFG, as also illustrated in Figure 6.


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)

Histograms of absolute positional errors recorded throughout the specified tracking volume of the Aurora® V1 PFG. A) First half (z ∈[–300,–50] mm). B) Second half (z ∈[–550,–300] mm)
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 0007: Histograms of absolute positional errors recorded throughout the specified tracking volume of the Aurora® V1 PFG. A) First half (z ∈[–300,–50] mm). B) Second half (z ∈[–550,–300] mm)
Mentions: The graphs of Figure 6 offer a qualitative appreciation of the measured positional errors of the EMTS at different distances from the PFG. They were however only obtained from a small subset of the 486 measurements made throughout the detection volume. Figure 7 displays histograms of absolute positional errors (3D) for all data points but located in the specified tracking volume of the Aurora® V1 PFG (a cube of 500 × 500 × 500 mm3). Errors associated with the first and second halves of the volume are presented. It can be seen that significantly lower positional errors are measured in the first half of the volume. Mean positional errors are respectively 3.4 mm for the first half, and 26 mm for the second one. The largest errors measured in the second half occur at the farthest distances (z = –550 mm) of the PFG, as also illustrated in Figure 6.

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