Analysis on the Variation of Respiratory organ motion and a Preliminary Feasibility Study for a Voice Coaching Technique to Improve the Reproducibility of Respiratory Cycle between Tteatiments

呼吸器官運動之變異性分析及呼吸導引技術之可行性研究

李必忍(James C. Li) ； 劉文山(Wen-Shan Liu) ； 郭祥吉(Hsiang-Chi Kuo) ； 陳理妙(Li-Miao Chen) ； 黃英強(David Huang) ； 徐啟徫(Chi-Wei Hsu) ； 張席昌(His-Chang Chang)

《放射治療與腫瘤學》 9卷1期 (2002/03) Pp. 1-12

https://doi.org/10.6316/TRO/200209(1)1

摘要

目的：放射治療的進步允許腫瘤劑量的提昇，從而促進更高的腫瘤控制率，然而其複雜性也需相對的嚴格控制器官運動造成之不確定度。器官運動造成之不確定度主要可分為（一）體內器官運動形成電腦斷層影像之假影；（二）器官運動影響治療中之劑量分布；（三）器官運動影響分次治療間之劑量。對橫隔膜上下之腫瘤，呼吸是影響體內器官運動之主要因素。為了進一步瞭解呼吸造成器官運動之大小，本文探討（一）自由呼吸與閉氣呼吸腫瘤與重要器官之形狀大小差異；（二）呼吸器官在頭尾方向之位移大小；（三）研究以呼吸導引技術改善治療間呼吸週期與器官運動之變異。材料與方法：本實驗資料來源為西元2001年3月至10月間於本院從事胸腹部放射治療之病患，使用材料與方法包括螺旋式電腦斷層掃瞄機各取兩組影像及運用立即式呼吸同步透視影像觀察體內器官運動。結果與討論：本分析顯示自由呼吸影像與閉氣影像差別甚大。橫隔膜在頭尾方向之位移可達15.5±3.5 mm，胰臟則有13.7±2.4 mm。本實驗顯示呼吸導引技術可改善某些呼吸不穩定患者之呼吸週期，從而能有效的尋求進一步控制其體內呼吸器官運動，至於某些病患其呼吸原本即已規律者，呼吸導引對其反而不利。

關鍵字

治療中 ； 治療間 ； 呼吸器官運動

並列摘要

Purpose: New advances in radiotherapy technology enable us to attain higher dose delivery to tumor region, resulting in greater tumor control probability, with this sophistication there is more demand to control the uncertainties contributed by organ motion. The organ motion related uncertainties can be mainly classified into three main categories: (I) the blurring of planning images due to internal organ motion during CT scan acquisition; (II) intrafractional organ motion that affect the dose distribution within a single treatment delivery; (III) interfractional organ motion that affect the dose distribution between treatments. For patients with supradiagphragmatic and infradiagphragmatic tumor, respiration is a major factor that causes the displacement of the internal organ. For further under standing the magnitude of the respiratory organ motion, we endeavor to investigate: (I) the geometrical differences in spatial displacement of the tumor and critical organ while in free breathing status and breath holding status; (II) measures the magnitude of the respiratory organ motion in the cranio-caudal direction; (III) makes a preliminary feasibility study of the coaching breathing technique to improve the reproducibility of the respiratory cycle and hence reduce the variation of organ motion in between treatment. Results and Methods: The data were collected between March 2001 to October 2001in our department from subjects undergoing radiation therapy of the thoracic and abdominal regions using our spiral CT and real time Respiratory Gating system to measure and analyze the variation of respiratory organ motion. A voice coaching technique is designed to improve the consistency of the respiration cycles. Results and Conclusions: Our analysis shows a significant variation of tumor and organ geometry between free breathing and breath holding state. The cranio-caudal displacement are 15.5±3.5 mm for diaphragm and 13.7±2.4 mm for pancreas, respectively. For patients in our study, coaching technique may improve the reproducibility for those patient whose breathing cycles is not consistent within intrafraction treatment, but not for those with consistent cycles.

並列關鍵字

Intrafraction ； Interfraction ； Respiratory organ motion