Validation of accuracy in image co-registration with computed tomography and magnetic resonance imaging in Gamma Knife radiosurgery.
The latest version of Leksell GammaPlan (LGP) is equipped with Digital Imaging and Communication in Medicine (DICOM) image-processing functions including image co-registration. Diagnostic magnetic resonance imaging (MRI) taken prior to Gamma Knife treatment is available for virtual treatment pre-planning. On the treatment day, actual dose planning is completed on stereotactic MRI or computed tomography (CT) (with a frame) after co-registration with the diagnostic MRI and in association with the virtual dose distributions. This study assesses the accuracy of image co-registration in a phantom study and evaluates its usefulness in clinical cases. Images of three kinds of phantoms and 11 patients are evaluated. In the phantom study, co-registration errors of the 3D coordinates were measured in overall stereotactic space and compared between stereotactic CT and diagnostic CT, stereotactic MRI and diagnostic MRI, stereotactic CT and diagnostic MRI, and stereotactic MRI and diagnostic MRI co-registered with stereotactic CT. In the clinical study, target contours were compared between stereotactic MRI and diagnostic MRI co-registered with stereotactic CT. The mean errors of coordinates between images were < 1 mm in all measurement areas in both the phantom and clinical patient studies. The co-registration function implemented in LGP has sufficient geometrical accuracy to assure appropriate dose planning in clinical use.
Department of Radiological Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan Nagoya Radiosurgery Center, Nagoya Kyoritsu Hospital, Nagoya, Aichi, Japan hnakazawa@kaikou.or.jp.
Hisato
H
Nakazawa
Department of Radiology and Radiation Oncology, Aichi Medical University, Nagakute, Aichi, Japan.
Yoshimasa
Y
Mori
Department of Radiological Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan.
Masataka
M
Komori
Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan.
Yuta
Y
Shibamoto
Nagoya Radiosurgery Center, Nagoya Kyoritsu Hospital, Nagoya, Aichi, Japan.
Takahiko
T
Tsugawa
Nagoya Radiosurgery Center, Nagoya Kyoritsu Hospital, Nagoya, Aichi, Japan.
Tatsuya
T
Kobayashi
Nagoya Radiosurgery Center, Nagoya Kyoritsu Hospital, Nagoya, Aichi, Japan.
Chisa
C
Hashizume
D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D064847:Multimodal Imaging / Q000295:instrumentation / Q000379:methods*; D009464:Neuroma, Acoustic / Q000175:diagnosis* / Q000601:surgery*; D019047:Phantoms, Imaging; D016634:Radiosurgery / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
co-registration; computed tomography; magnetic resonance imaging; pre-planning; stereotactic radiosurgery