Abstract
Background
The use of optical surface positioning to support or replace X-ray-based image-guided radiotherapy (IGRT) may reduce patient exposure to extra dose. In specifically designed phantom tests, we analyzed the potential of a new scanning device preclinically. The system’s clinical performance was evaluated in comparison to cone-beam computed tomography (CBCT) in a prospective study.
Materials and methods
We first evaluated the scanning performance in terms of accuracy and reproducibility using phantom tests. An institutional review board (IRB)-approved clinical evaluation encompassing 224 fractions in 13 patients treated in three different regions (head and neck, thorax, pelvis) was then performed. Patients were first positioned using CBCT and then scanned with the CatalystTM (C-RAD, Uppsala, Sweden) optical system to define the resulting difference vector.
Results
Individual system settings are necessary for different scanning conditions. Reproducibility tests with phantoms showed a mean difference of 0.25 ± 0.21 cm. Accuracy tests showed a mean difference of less than 0.52 ± 0.41 cm. Considering all patients, clinical data showed residual target position differences between CatalystTM (surface-driven) and CBCT (target-driven) systems within 0.07 ± 0.28 cm/− 0.13 ± 0.40 cm/0.15 ± 0.36 cm/0.11 ± 1.57°/− 0.43 ± 1.68/− 0.10 ± 1.67° (lateral/longitudinal/vertical/rotation/roll/pitch).
Conclusion
Scanning quality depends on the color and shape of the scanned surface. Upon prospective clinical evaluation, excellent agreement between target- and contour driven positioning was observed. CatalystTM may reduce CBCT scan frequency in patients where tumor location is fixed relative to the surface.
Zusammenfassung
Hintergrund
Die optische Oberflächenpositionierung zur Unterstützung oder zum Ersatz von röntgenstrahlenbasierender IGRT kann die Strahlenbelastung des Patienten reduzieren. In speziellen Phantomtest wurde das Potential eines neuen Systems untersucht und das klinische Potential im Vergleich zur Cone-Beam-Computertomographie (CBCT) in einer prospektiven Studie evaluiert.
Materialien und Methoden
Wir evaluierten das Potential des Systems bezüglich Genauigkeit und Reproduzierbarkeit in Phantomtests und analysierten eine durch die IRB genehmigte Studie, welche 224 Fraktionen aus 13 Patienten in 3 unterschiedlichen Regionen umfasste (Kopf-Hals, Thorax und Abdomen). Die Patienten wurden zuerst mit CBCT positioniert und anschließend mit dem optischen System CatalystTM (C-RAD, Uppsala, Schweden) gescannt, um den Unterschied zu ermitteln.
Ergebnisse
Individuelle Systemeinstellungen sind für unterschiedliche Abtastbedingungen notwendig. Die Reproduzierbarkeitstests anhand Phantomen zeigten eine mittlere Abweichung von 0,25 ± 0,21 cm. Genauigkeitsanalysen ergaben eine mittlere Abweichung von weniger als 0,52 ± 0,41 cm. Die klinischen Ergebnisse wiesen eine Abweichung von CatalystTM (oberflächenbasiert) zu CBCT (zielvolumenbasiert) über alle Patienten von 0,07 ± 0,28 cm/− 0,13 ± 0,40 cm/0,15 ± 0,36 cm/0,11 ± 1,57°/− 0,43 ± 1,68/− 0,10 ± 1,67° (lateral/longitudinal/vertikal/Rotation/Rollen/Kippen) auf.
Schlussfolgerung
Die Abtastqualität hängt von Farbe und Kontur der Oberfläche ab. Die Auswertung der klinischen Studie zeigte hervorragende Übereinstimmung zwischen zielvolumen- und oberflächenbasierter Positionierung. CatalystTM ermöglicht eine Reduzierung der CBCT-Anzahl bei Patienten mit fester Tumoroberflächenrelation.
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References
Walter C et al (2007) Phantom and in-vivo measurements of dose exposure by image-guided radiotherapy (IGRT): MV portal images vs. kV portal images vs. cone-beam CT. Radiother Oncol 85(3):418–423
Amer A et al (2007) Imaging doses from the Elekta Synergy X-ray cone beam CT system. Br J Radiol 80(954):476–482
Guckenberger M et al (2012) Motion compensation in radiotherapy. Crit Rev Biomed Eng 40(3):187–197
Pallotta S et al (2012) A phantom evaluation of Sentinel(™), a commercial laser/camera surface imaging system for patient setup verification in radiotherapy. Med Phys 39(2):706–712
Stieler F et al (2012) Clinical evaluation of a commercial surface-imaging system for patient positioning in radiotherapy. Strahlenther Onkol 188(12):1080–1084
Gopan O, Wu Q (2012) Evaluation of the accuracy of a 3D surface imaging system for patient setup in head and neck cancer radiotherapy. Int J Radiat Oncol Biol Phys 84(2):547–552
Moser T et al (2012) Clinical evaluation of a laser surface scanning system in 120 patients for improving daily setup accuracy in fractionated radiation therapy. Int J Radiat Oncol Biol Phys 85(3):846–853
Pallotta S et al (2013) Accuracy of a 3D lasercamera surface imaging system for setup verification of the pelvic and thoracic regions in radiotherapy treatments. Med Phys 40(1):011710
Kauweloa KI et al (2012) GateCT surface tracking system for respiratory signal reconstruction in 4DCT imaging. Med Phys 39(1):492–502
Wolff D et al (2009) Volumetric modulated arc therapy (VMAT) vs. serial tomotherapy, step-and-shoot IMRT and 3D-conformal RT for treatment of prostate cancer. Radiother Oncol 93(2):226–233
Stieler F et al (2011) A comparison of several modulated radiotherapy techniques for head and neck cancer and dosimetric validation of VMAT. Radiother Oncol 101(3):388–393
Hansen EK et al (2006) Repeat CT imaging and replanning during the course of IMRT for head-and-neck cancer. Int J Radiat Oncol Biol Phys 64(2):355–362
Ho KF et al (2012) Monitoring dosimetric impact of weight loss with kilovoltage (kV) cone beam CT (CBCT) during parotid-sparing IMRT and concurrent chemotherapy. Int J Radiat Oncol Biol Phys 82(3):e375–e382
Giraud P et al (2003) Respiration-gated radiotherapy: current techniques and potential benefits. Cancer Radiother 7(Suppl 1):15s–25s
Herk M van et al (2000) The probability of correct target dosage: dose-population histograms for deriving treatment margins in radiotherapy. Int J Radiat Oncol Biol Phys 47(4):1121–1135
Financial support
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).
Compliance with ethical guidelines
Conflict of interest. F. Stieler, F. Wenz, M. Shi and F. Lohr state that there are no conflicts of interest.
All studies on humans described in the present manuscript were carried out with the approval of the responsible ethics committee and in accordance with national law and the Helsinki Declaration of 1975 (in its current, revised form). Informed consent was obtained from all patients included in studies.
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Stieler, F., Wenz, F., Shi, M. et al. A novel surface imaging system for patient positioning and surveillance during radiotherapy. Strahlenther Onkol 189, 938–944 (2013). https://doi.org/10.1007/s00066-013-0441-z
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DOI: https://doi.org/10.1007/s00066-013-0441-z
Keywords
- Cone-bean computed tomography
- Image-guided radiotherapy
- Head and neck cancer
- Linear accelerator
- Target volume