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SU‐E‐J‐76: Clinical Use of a Real‐Time Surface Image‐Guided Positioning and Tracking System in Proton Therapy
Author(s) -
Hsi W,
Kang Y,
Ding X,
Mascia A,
Ramirez E,
Zheng Y,
Zeidan O
Publication year - 2012
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.4734911
Subject(s) - proton therapy , image guided radiation therapy , nuclear medicine , image registration , medicine , tracking (education) , proton , biomedical engineering , perpendicular , rotation (mathematics) , medical imaging , computer science , radiation therapy , physics , artificial intelligence , radiology , mathematics , image (mathematics) , geometry , psychology , pedagogy , quantum mechanics
Topic of interest: Clinical applications of AlignRT 3‐cameras real‐time surface image‐guided positioning system (IGPS) for positioning patients to reduce the number of X‐ray images and tracking intra‐fractional movements in proton therapy.Purposes: To position patients and track the intra‐fractional movements, the AlignRT system was implemented in proton incline‐beam‐line (IBL) at Procure Oklahoma‐City center. Methods: The AlignRT3c system was configured near perpendicular to the gantry rotation for accommodating the X‐ray IGPS. To evaluate positioning accuracy, more than 10 surfaces of each patient for ten patients with intracranial tumors were acquired after patients positioned by X‐ray IGPS. Displacements between acquired surfaces and the reference surface taken at 1st day of treatment were examined. Intra‐fractional movements with respiratory was studied with gated surface that allows setting the reference surface for patient at exhale during breathing. Intra‐fractional movements due to respiratory were monitored on 10 sections of each patient for three patients with thoracic tumors. Results: Accuracy of positioning patient is 2.0 mm at both anterior‐posterior and lateral directions, and is 3.5 mm in superior‐inferior (SI) direction by aligning the surfaces of masks. Observed larger displacements along SI direction can be due to patient's movements within the mask. Periodical displacements within 5 mm compared to its reference were seen for the three patients with thorax tumors. However, 10 mm sharp displacements with a few seconds were observed when patient moved the body. Conclusions: We have implemented the first AlignRT3c IGPS for proton therapy for positioning patients within 2.0 mm, and successfully tracked intra‐fractional respiratory motion during treatment after positioning patient.