基于4DCT探讨部分乳腺外照射术腔位移与体内外标记位移相关性

Correlations between displacements of GTV, surgical clips, and skin markers in external-beam partial breast irradiation：a study based on 4DCT

目的 基于自由呼吸状态下4DCT探讨结合金属夹和血清肿所勾画术腔靶区位移与术腔金属夹及体表金属标记位移的相关性.方法 在15例乳腺癌患者4DCT的10个时相图像上基于金属夹和血清肿结合勾画术腔靶区并定义为GTV,分别标记选定金属夹及体表金属标记,测定GTV、选定金属夹及体表标记三维方向位移并Pearson法分析位移相关性.结果 前后方向GTV位移与最近胸壁层金属夹位移呈正相关（r=0.643,P=0.013）,上下方向GTV位移与最下层金属夹及前胸壁体表标记位移均呈正相关（r =0.857、0.643,P=0.002、0.013）.左右、前后方向同体侧体表标记位移与最外侧金属夹位移呈正相关（r=0.757、0.697,P=0.001、0.025）,而上下方向两者呈负相关（r=-0.647,P=0.043）.前后方向前胸壁体表标记与最近胸壁侧金属夹位移呈正相关（r=0.738,P=0.015）.结论 基于金属夹和血清肿结合所勾画术腔GTV位移与术腔各边界金属夹及体表金属标记位移的关联性需个体化对待,术腔各边界金属夹与体表金属标记位移的关联性也需个体化对待.

Objective To investigate the correlations between the displacements of surgical clips,skin markers and the gross tumor volume （GTV） delineated by surgical clip and seroma based on fourdimensional computed tomography （4DCT） during normal breathing.Methods On each of the 10 respiratory phases of 4DCT with 15 patients of breast cancer,the surgical cavity,which was defined as GTV and formed by both surgical clips and seroma,all surgical clips in the cavity,and skin markers on the skin were delineated by the same radiation oncologist.The center displacements of GTV,selected boundary surgical clips and skin markers in the left-right （LR）,anterior-posterior （AP）,and superior-inferior （SI） directions were recorded and analyzed by Pearson method.Results In the AP direction,there was a positive correlation between the displacements of the GTV and the inner clip （r =0.643,P =O.013）.In the SI direction,the displacement of GTV was positively correlated with those of the lower clip and the skin marker at anterior body midline （r =0.857 and 0.643,P =0.002 and 0.013）.In the LR and AP directions,there was a positive correlation between the displacements of the outer clip and the ipsilateral skin marker （r =0.757 and 0.697,P =0.001 and 0.025）,but they were negatively correlated with each other in the SI direction （r =-0.647,P =0.043）.In the AP direction,there was a positive correlation between the displacements of the inner clip and the skin marker at the anterior body midline （r =0.738,P =0.015）.Conclusions The correlations between the displacement of GTV delineated by surgical clips and seroma and the displacements of surgical slips and skin markers vary under different conditions,and so does the correlation between the displacements of surgical clips and skin markers.