利用影像導引系統比較兩種腹板對直腸癌放射治療準確性之分析

Comparative Studies of the Reproducibility of Two Belly Board used in Prone-Positioned Radiation Therapy in Rectal Cancer

王喬槿(Chiao-Chin Wang) ； 王嘉儁(Chia-Chun Wang) ； 曾怡瑾(Yi-Chin Tseng)

《台灣應用輻射與同位素雜誌》 10卷4期 (2014/12) Pp. 997-1002

摘要

放射治療時擺位再現性及固定性關係著治療之準確性，因此固定治療姿勢之輔具基於符合人體工學而發展得更多元且完善。擺位之準確性及再現性可利用影像導引系統評估病患於治療時位置固定性及準確性。本研究目的使用像導引系統錐狀射束電腦斷層掃描(Cone beam Computed Tomography，CBCT)評估兩種腹板(腹板1 MedTec®belly board，腹板2 Contoura^(TM) belly board)於直腸癌放射治療位置準確性分析。收集2013年1月至2013年9月總共20位直腸癌病人療程期間CBCT在X、Y、Z三個軸向平均位移誤差。將三軸誤差共分為前、中、後三階段。其研究結果為：1.前期腹板1之X、Y、Z三個軸向的平均位移誤差(Mean ± SD)為：0.27±0.11cm、0.18±0.09cm、0.48±0.20cm；腹板2之X、Y、Z三個軸向的位移平均差為：0.19±0.11cm、0.16±0.05cm、0.18±0.09cm。2.中期腹板1之X、Y、Z三個軸向的平均位移誤差為：0.33±0.18、0.26±0.25cm、0.5±0.24cm；腹板2之X、Y、Z三個軸向的位移平均差為：0.1±0.08cm、0.16±0.23cm、0.46±0.09cm。3.後期腹板1之X、Y、Z三個軸向的平均位移誤差為：0.3±0.14 cm、0.96±0.12cm、0.5±0.24cm腹板2之X、Y、Z 三個軸向的位移平均差為：0.23±0.16cm、0.16±0.09cm、0.36±0.06cm。使用腹板2誤差值相對於腹板1較小，其原因為腹板2海綿鬆軟材質與順著人體型狀的弧度設計對病患而言降低了俯臥時因漲尿壓迫膀胱造成的不舒適，進而提高了位置再現性及準確性。

關鍵字

直腸癌 ； 準確性 ； 錐狀射束電腦斷層掃描 ； 腹板

並列摘要

The accuracy of radiation therapy in rectal cancer is highly related to the reproducibility of body positioning which has been aided by the improvement of more ergonomic immobilization devices. The goal of this work is to use image guiding cone-beam computed tomography (CBCT), to evaluate the patient position between two types of commercial belly board (BB). The two types of BB that we use in our study are MedTec® belly board (BB1), and CIVCO® Contoura^(TM) Belly Board (BB2). Twenty rectal cancer patients using prone-position volumetric modulated arc therapy (VMAT), from January 2013 to September 2013 were enrolled into this study. The evaluation was done by using automatic bony structure alignment and the shifting errors for the X, Y, and Z axes were analyzed. The average shifting errors for the X, Y, and Z axes were 0.27± 0.11cm、0.18±0.09cm、0.48±0.20cm using BB1 and 0.19±0.11cm、0.16±0.05cm、0.18±0.09cm using BB2. The errors were smaller for BB2, probably due to the spongy and body curve fitting interiors of BB2. It can significantly decrease the discomfort of having a full bladder and lying in a prone position, therefore it highly increases the reproducibility and accuracy of radiation therapy.

並列關鍵字

Rectal Cancer ； Accuracy ； Cone-Beam Computed Tomography ； Belly