顱內放射手術治療時間長短與治療位移誤差之探討

Investigation of Relationship between Intrafractional Displacement and Treatment Time in Intracranial Radiosurgery

林胤均(Yin-Chun Lin) ； 張瑋莉(Wei-Li Cheng) ； 曾漢民(Ham-Min Tseng) ； 成佳憲(Jason Chia-Hsien Cheng) ； 蕭輔仁(Fu-Ren Xiao) ； 陳敞牧(Chang-Mu Chen) ； 張璞曾(Fok-Ching Chong) ； 王駿瑋(Chun-Wei Wang)

《中華放射線技術學雜誌》 34卷3期 (2010/09) Pp. 161-168

https://doi.org/10.30045/CJRT.201009.0002

摘要

隨著體外放射線治療技術的發展愈加精進，放射線治療的精準度也更為重要。本研究針對接受顱內放射手術治療之病患，利用電腦刀的治療中取像設備來增加即時影像的取得及比對頻率，以了解治療中位移誤差變化，並進一步評估治療時間長短對於治療中誤差所造成的影響。在本研究的40筆頭部電腦刀治療紀錄當中，發現開始治療的30分鐘內，在直線軸頭腳(SI)、腹背(AP)方向的治療中誤差會隨著治療時間而增加，且在治療開始的前15分鐘，其平均位移誤差在各直線軸均小於1 mm，但若治療時間超過15分鐘，其SI及AP方向的平均位移誤差將顯著增加為2.63倍及2.81倍。當治療時間大於15分鐘時，在SI、RL、AP方向及三度空間向量上的累積誤差將各有1.5%、2.0%、1.0%、13.5%會超過1 mm。由上述結果可知，若臨床上有執行高精準度體外放射線治療之需要時，當治療時間超過15分鐘時應再額外增加安全邊距，以確保治療之精準度。

關鍵字

電腦刀 ； 立體定位放射手術 ； 治療中誤差 ； 影像導引

並列摘要

As radiotherapy technology advances, the accuracy of radiation delivery becomes more and more important. The goal of this study was to evaluate the displacement changes during intracranial radiosurgery and the impact of treatment time on displacement. Compared with previously published studies, we focused on patients who received intracranial radiosurgery with a real-time image guidance system and greater frequency in image acquisition with CyberKnife. A total of 40 treatment records 3,829 images were included in this study. We analyzed the translation and rotation displacements in the first 30 minutes of treatment with 3-minute intervals. With longer treatment times, larger displacements were observed in the superior-inferior (SI) and anterior-posterior (AP) directions. The mean displacement in all three translation directions was ＜1 mm in the first 15 minutes of treatment. When the treatment time exceeded 15 minutes, the mean of displacement increased to 2.63 times and 2.81 times in SI and AP directions, respectively. The frequencies of displacement beyond 1 mm in the superior-inferior, right-left, anterior-posterior, 3-dimensional directions were 1.5%, 2.0%, 1.0%, and 13.5%, respectively. Based on these observations, a more generous margin is needed when the treatment time exceeds 15 minutes.

並列關鍵字

CyberKnife® ； intrafractional error ； image guidance