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Strahlentherapie und Onkologie

, Volume 188, Issue 12, pp 1080–1084 | Cite as

Clinical evaluation of a commercial surface-imaging system for patient positioning in radiotherapy

  • F. StielerEmail author
  • F. Wenz
  • D. Scherrer
  • M. Bernhardt
  • F. Lohr
Original article

Abstract

Background

Laser scanning-based patient surface positioning and surveillance may complement image-guided radiotherapy (IGRT) as a nonradiation-based approach. We investigated the performance of an optical system compared to standard kilovoltage cone-beam computed tomography (CBCT) and its potential to reduce the number of daily CBCTs.

Patients and methods

We analyzed the patient positioning of 153 treatment fractions in 21 patients applied to three different treatment regions. Patients were first scanned with CBCT, shifted to the optimal isocenter position, and an optical scan was performed to verify the matching in relation to CBCT.

Results

For the head-and-neck region, the lateral/longitudinal/vertical/rotational/roll and pitch shift was 0.9 ± 1.8 mm/−2.7± 3.8 mm/−0.8± 3.6 mm/0.0± 1.1°/−0.5± 2.1°/0.2± 1.6°. For the thorax, the lateral/longitudinal/vertical/roll and pitch shift was −1.2± 3.6 mm/0.8± 5.1 mm/0.8± 4.3 mm/0.6± 1.4°/0.1± 0.9°/0.3± 1.0°. For the pelvis, the respective values were −2.5± 4.1 mm/4.6± 7.3 mm/−5.1± 7.4 mm/0.3± 1.1°/-0.5± 1.0°/0.3± 2.1°. In total, the recorded disagreement was −1.0± 3.6 mm/1.0± 6.3 mm/−1.8± 5.9 mm/0.3± 1.2°/−0.3± 1.5°/0.2± 1.7°.

Conclusion

This analysis showed good agreement between the optical scanner approach and CBCT. The optical system holds potential to ensure precise patient positioning and reduced CBCT frequency in tumor locations with fixed relation to surface structures.

Keywords

Image-guided radiotherapy Optical surface laser scanner Cone-beam computed tomography Patient positioning Tumor location 

Klinische Bewertung eines kommerziellen Oberflächenbildgebungssystems zur Patientenpositionierung bei Strahlentherapie

Zusammenfassung

Einleitung

Die Abtastung der Patientenoberfläche mittels Laser zur Positionierung hat das Potenzial, die bildgesteuerte Strahlentherapie zu ergänzen. Wir untersuchten die Leistung eines optischen Systems im Vergleich zur normalen digitalen Volumentomographie („kV cone beam computed tomography“, CBCT) und deren Potenzial, die Zahl der notwendigen Positionierungscomputertomographien zu reduzieren.

Material und Methoden

Wir untersuchten die Patientenpositionierung bei 153 Fraktionen an 21 Patienten (drei verschiedene Bestrahlungsregionen). Die Patienten wurden zuerst mit der CBCT positioniert und danach mit dem optischen System gescannt, um die Abweichung zur CBCT zu erfassen.

Ergebnisse

Für die Kopf-Hals-Region betrugen die Abweichungen in lateraler/longitudinaler/vertikaler/rotationaler/rollender/kippender Richtung 0,9± 1,8 mm/−2,7± 3,8 mm/-0,8± 3,6 mm/0,0± 1,1°/−0,5± 2,1°/0,2± 1,6°. Für die Thoraxregion betrug die laterale/longitudinale/vertikale/rotationale/rollende/kippende Abweichung −1,2± 3,6 mm/0,8± 5,1 mm/0,8± 4,3 mm/0,6 ± 1,4°/0,1 ± 0,9°/0,3 ± 1,0°. Für die Beckenregion waren die entsprechenden Abweichungen −2,5 ± 4,1 mm/4,6 ± 7,3 mm/−5,1 ± 7,4 mm/0,3 ± 1,1°/−0,5 ± 1,0°/0,3 ± 2,1°. Die Abweichung über alle Fraktionen betrug −1,0 ± 3,6 mm/1,0 ± 6,3 mm/−1,8 ± 5,9 mm/0,3 ± 1,2°/−0,3 ± 1,5°/0,2 ± 1,7°.

Fazit

Die Analyse zeigte eine gute Übereinstimmung zwischen dem optischen System und der CBCT. Das optische System hat das Potenzial zur präzisen Patientenpositionierung mit verminderter Anzahl von CBCT-Aufnahmen bei Tumorlokalisationen mit fester Relation zur Patientenoberfläche.

Schlüsselwörter

Bildgesteuerte Strahlentherapie Optischer Oberflächenscanner Digitale Volumentomographie Patientenpositionierung Tumorlokalisationen 

Notes

Acknowledgments

This work was supported within the framework of a Research Cooperation Agreement between the Department of Radiation Oncology, Mannheim University Medical Center, and C-Rad (Sweden).

Conflict of interest

On behalf of all authors, the corresponding author states the following: Research agreements with C-Rad and Elekta Inc. regarding image guidance and patient positioning are in place.

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Copyright information

© Urban & Vogel 2012

Authors and Affiliations

  • F. Stieler
    • 1
    Email author
  • F. Wenz
    • 1
  • D. Scherrer
    • 1
  • M. Bernhardt
    • 1
  • F. Lohr
    • 1
  1. 1.Department of Radiation Therapy and Radiation OncologyUniversity Medical Center Mannheim, University of HeidelbergMannheimGermany

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