TY - JOUR
T1 - Patient set-up verification by infrared optical localization and body surface sensing in breast radiation therapy
AU - Spadea, Maria Francesca
AU - Baroni, Guido
AU - Riboldi, Marco
AU - Tagaste, Barbara
AU - Garibaldi, Cristina
AU - Orecchia, Roberto
AU - Pedotti, Antonio
PY - 2006/5
Y1 - 2006/5
N2 - Background and purpose: The aim of the study was to investigate the clinical application of a technique for patient set-up verification in breast cancer radiotherapy, based on the 3D localization of a hybrid configuration of surface control points. Materials and methods: An infrared optical tracker provided the 3D position of two passive markers and 10 laser spots placed around and within the irradiation field on nine patients. A fast iterative constrained minimization procedure was applied to detect and compensate patient set-up errors, through the control points registration with reference data coming from treatment plan (markers reference position, CT-based surface model). Results: The application of the corrective spatial transformation estimated by the registration procedure led to significant improvement of patient set-up. Median value of 3D errors affecting three additional verification markers within the irradiation field decreased from 5.7 to 3.5 mm. Errors variability (25-75%) decreased from 3.2 to 2.1 mm. Laser spots registration on the reference surface model was documented to contribute substantially to set-up errors compensation. Conclusions: Patient set-up verification through a hybrid set of control points and constrained surface minimization algorithm was confirmed to be feasible in clinical practice and to provide valuable information for the improvement of the quality of patient set-up, with minimal requirement of operator-dependant procedures. The technique combines conveniently the advantages of passive markers based methods and surface registration techniques, by featuring immediate and robust estimation of the set-up accuracy from a redundant dataset.
AB - Background and purpose: The aim of the study was to investigate the clinical application of a technique for patient set-up verification in breast cancer radiotherapy, based on the 3D localization of a hybrid configuration of surface control points. Materials and methods: An infrared optical tracker provided the 3D position of two passive markers and 10 laser spots placed around and within the irradiation field on nine patients. A fast iterative constrained minimization procedure was applied to detect and compensate patient set-up errors, through the control points registration with reference data coming from treatment plan (markers reference position, CT-based surface model). Results: The application of the corrective spatial transformation estimated by the registration procedure led to significant improvement of patient set-up. Median value of 3D errors affecting three additional verification markers within the irradiation field decreased from 5.7 to 3.5 mm. Errors variability (25-75%) decreased from 3.2 to 2.1 mm. Laser spots registration on the reference surface model was documented to contribute substantially to set-up errors compensation. Conclusions: Patient set-up verification through a hybrid set of control points and constrained surface minimization algorithm was confirmed to be feasible in clinical practice and to provide valuable information for the improvement of the quality of patient set-up, with minimal requirement of operator-dependant procedures. The technique combines conveniently the advantages of passive markers based methods and surface registration techniques, by featuring immediate and robust estimation of the set-up accuracy from a redundant dataset.
KW - Breast cancer
KW - Infrared localization
KW - Quality assurance
KW - Radiotherapy
KW - Surface registration
UR - http://www.scopus.com/inward/record.url?scp=33745103374&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33745103374&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2006.02.011
DO - 10.1016/j.radonc.2006.02.011
M3 - Article
C2 - 16574263
AN - SCOPUS:33745103374
VL - 79
SP - 170
EP - 178
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
SN - 0167-8140
IS - 2
ER -