Patient positioning in radiotherapy based on surface imaging using time of flight cameras

To evaluate the patient positioning accuracy in radiotherapy using a stereo-time of flight (ToF)-camera system.

A system using two ToF cameras was used to scan the surface of the patients in order to position them daily on the treatment couch. The obtained point clouds were registered to (a) detect translations applied to the table (intrafraction motion) and (b) predict the displacement to be applied in order to place the patient in its reference position (interfraction motion). The measures provided by this system were compared to the effectively applied translations. The authors analyzed 150 fractions including lung, pelvis/prostate, and head and neck cancer patients.

The authors obtained small absolute errors for displacement detection: 0.8 ± 0.7, 0.8 ± 0.7, and 0.7 ± 0.6 mm along the vertical, longitudinal, and lateral axes, respectively, and 0.8 ± 0.7 mm for the total norm displacement. Lung cancer patients presented the largest errors with a respective mean of 1.1 ± 0.9, 0.9 ± 0.9, and 0.8 ± 0.7 mm.

The proposed stereo-ToF system allows for sufficient accuracy and faster patient repositioning in radiotherapy. Its capability to track the complete patient surface in real time could allow, in the future, not only for an accurate positioning but also a real time tracking of any patient intrafraction motion (translation, involuntary, and breathing).

Medical physics. 2016 Aug [Epub]

M Gilles, H Fayad, P Miglierini, J F Clement, S Scheib, L Cozzi, J Bert, N Boussion, U Schick, O Pradier, D Visvikis

INSERM, UMR 1101, LaTIM, Brest 29609, France., INSERM, UMR 1101, LaTIM, Brest 29609, France., Academic Radiotherapy Department, CHRU Morvan, Brest 29200, France., INSERM, UMR 1101, LaTIM, Brest 29609, France., Varian Medical Systems Imaging Laboratory GmbH, Baden-Daettwil 5405, Switzerland., Radiotherapy and Radiosurgery Department, Instituto Clinico Humanitas, Rozzano 20089, Italy., INSERM, UMR 1101, LaTIM, Brest 29609, France., INSERM, UMR 1101, LaTIM, Brest 29609, France and Academic Radiotherapy Department, CHRU Morvan, Brest 29200, France., INSERM, UMR 1101, LaTIM, Brest 29609, France and Academic Radiotherapy Department, CHRU Morvan, Brest 29200, France., INSERM, UMR 1101, LaTIM, Brest 29609, France and Academic Radiotherapy Department, CHRU Morvan, Brest 29200, France., INSERM, UMR 1101, LaTIM, Brest 29609, France.

E-Newsletters

Newsletter subscription

Free Daily and Weekly newsletters offered by content of interest

The fields of GU Oncology and Urology are rapidly advancing. Sign up today for articles, videos, conference highlights and abstracts from peer-review publications by disease and condition delivered to your inbox and read on the go.

Subscribe