目的：電腦刀是一種影像導引式立體定位放射手術系統。本研究的主要目的為確認影像導引系統
的準確性、機械手臂的準確性及劑量的準確性，以確保臨床治療品質。同時量測劑量參數作為臨
床治療計劃的依據。
材料與方法：電腦刀是由一個機械手臂及兩組 kV 的 X –ray 影像系統所組成的影像導引立體定位放射手術系統。對於機械手臂之準確性的確認，係依照原廠提供的 Isopost 之紅外線來測試機械手臂的每個照射位置在不同的 SAD 距離下是否與等中心點吻合。影像導引系統（Target LocatingSystem）的測試是將系統分成 6 維頭顱追蹤模組（6D Skull Tracking Mode）與 6 維顱外標記追蹤模組（6D Fiducial Tracking Mode），以假體來確認影像導引系統的準確性。至於整體電腦刀系統（包括電腦治療計劃系統、機械手臂、影像導引 系統、加速器的所有劑量輸出）則以 End-to-End 測試方法來確認其準確度。
結果：機械手臂在不同的 SAD 距離下，所有照射點誤差都小於 0.5 mm；至於影像導引系統無
論是 6 維頭顱追蹤模組（6D Skull Tracking Mode）或是 6 維顱外標記追蹤模組（6D Fiducial Tracking Mode）下的誤差皆小於 1 mm（包含平移軸及旋轉軸）。最後整體電腦刀系統的評估在使用 end-to-end 測試後其誤差值皆小於 1 mm。
結論：電腦刀系統可提供立體定位放射手術更精確的治療位置，同時透過影像導引的方式可確保
病人在治療過程中的移動誤差落在可接受的範圍內。

Purpose : To assure the accuracy of image-guided system, robotic arm, and dosimetry for Cyberknife unit and to prepared it for the clinical use.
Method and Materials : Cyberknife is consisted of one robotic arm with a 6MV Linac and one image guided system with two-sets of X-ray units. It is one of the dedicated equipment for stereotactic radiosurgery. The accuracy of the robotic arm was tested to verify the agreement between the arm
positions and the isocenters at various SAD using the Isopost system provided by the manufacture.
The accuracy of the Target Locating System (TLS) was tested by both 6D skull tracking mode and 6D fiducial tracking mode using a special phantom. As for the whole Cyberknife system, we applied “Endto-End” method, using anthropomorphic phantom and Gafchromic film, to verify its accuracy.
Results : The agreement of robotic arm positions and isocenters at various SAD were within 0.5 mm which is within the tolerance of the manufacture suggested value. For the test results of Target Locating System, the errors (including translation and rotation) are less than 0.5 mm for both tracking modes.
The end-to-end test results for the entire Cyberknife system are all better than 1 mm.
Conclusions : From the results of our Acceptance Tests and Commissioning, the Cyberknife could be used in clinic for radiosurgery procedures. The image-guided function for the unit makes it an accurate and effective radiation treatment modality for radiosurgery.