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Comparison of CT-MR Image Registrations of BrainLab Elements MBM SRS and Varian Eclipse

J Li*, Y Yu, H Liu, Thomas Jefferson University, Philadelphia, PA


(Sunday, 7/12/2020)   [Eastern Time (GMT-4)]

Room: AAPM ePoster Library

Purpose: To compare CT-MR image registrations of BrainLab Elements Multiple Brain Mets SRS (Elements MBM SRS) and Varian Eclipse for brain cancer treatment

Methods: CT and MR images of 12 brain patients were used in the study. The slice thickness of CT images was 1.25 mm and the pixel size was 0.8 mm. The slice thickness of MR images was 1 or 1.5 mm and the pixel size was ~1 mm. CT-MR image registrations using BrainLab Elements MBM SRS treatment planning system (V2.0) which has the capability of treating multiple brain metastases with single isocenter, and Varian Eclipse, a popularly used treatment planning system, of the latest version (V15.6), were compared. Automatic registration using similar region of interests (ROIs) were performed in the two systems, respectively. Registration results, i.e., transformations in 6-degree-of-freedom were compared, and the differences were calculated.

Results: The absolute differences in the registration results between the two systems were: 0.1±0.1 (range: 0-0.3) mm, 0.5±0.3 (range: 0.2-0.9) mm, 0.3±0.3 (range: 0-0.9) mm, in the lateral, anterior-posterior, and superior-inferior directions, respectively; and 0.2±0.2 (range: 0-0.8) degree, 0.2±0.2 (range: 0-0.5) degree, and 0.3±0.2 (range: 0-0.7) degree, in the pitch, rotation, and roll directions, respectively.

Conclusion: The differences between the two systems were less than 1 mm in any translational directions and less than 1 degree in any rotational directions. BrainLab Elements MBM SRS and Varian Eclipse provided comparable image registration results.


Radiation Therapy, Image Fusion


IM/TH- Image Registration: Multi-modality registration

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