Lakosi Ferenc, Gulyban Akos, Janvary Levente, Simoni Selma Ben-Mustapha, Jansen Nicolas, Seidel Laurence, Kovacs Arpad, Vavassis Peter, Coucke Philippe
Department of Radiation Oncology, University Hospital of Liège, Avenue de l'hôpital, B.35, 4000, Liège, Belgium,
Pathol Oncol Res. 2015 Sep;21(4):1051-8. doi: 10.1007/s12253-015-9932-9. Epub 2015 Apr 4.
To analyze respiratory motion of surgical clips, chest wall (CW) and the anterior displacement of the heart and its impact on heart dosimetry between prone (Pr) and supine (Su) positions during whole breast radiotherapy after breast conserving surgery. Sixteen patients underwent 4D-CT for radiotherapy planning in Pr and Su positions. Maximum inhale and maximum exhale phases were analyzed. Mean 3D vectorial displacements ± standard deviations (SD) of the surgical clips were measured. Volumetric changes of the CW were recorded and compared. Cardiac displacement was assessed by a volume between the inner surface of CW and the myocardium of the heart (CW/H-V). For left-sided cases, comparative dosimetry was performed in each position simulating no- (Pr-noC, Su-noC) versus daily correction protocols (Pr-C, Su-C). The movements of 81 surgical clips were analyzed. Prone positioning significantly reduced both the mean 3D vectorial displacements (1.1 ± 0.6 (Pr) vs. 2.0 ± 0.9 mm (Su), p < 0.01) and their variability (0.3 ± 0.2 vs. 0.5 ± 0.3 mm, p = 0.01). Respiration-induced volumetric changes of CW were also significantly lower in Pr (2.3 ± 4.9 vs. 9.6 ± 7.1 cm(3), p < 0.01). The CW/H-V was significantly smaller in Pr than in Su (39.9 ± 14.6 vs. 64.3 ± 28.2 cm(3), p < 0.01). Besides identical target coverage heart, left-anterior-descending coronary artery (LADCA) and ipsilateral lung dose parameters were lowered with Pr-C compared to Pr-noC, Su-C and Su-noC. Prone position significantly reduced respiration-related surgical clip movements, their variability as well as CW movements. Significant anterior heart displacement was observed in Pr. Prone position with daily online correction could maximize the heart and LADCA protection.
分析保乳手术后全乳放疗期间俯卧位（Pr）和仰卧位（Su）时手术夹的呼吸运动、胸壁（CW）及心脏的前向位移及其对心脏剂量测定的影响。16例患者在Pr位和Su位接受4D-CT用于放疗计划。分析最大吸气和最大呼气期。测量手术夹的平均三维矢量位移±标准差（SD）。记录并比较CW的体积变化。通过CW内表面与心脏心肌之间的体积（CW/H-V）评估心脏位移。对于左侧病例，在每个体位模拟无校正（Pr-noC，Su-noC）与每日校正方案（Pr-C，Su-C）进行比较剂量测定。分析了81个手术夹的运动。俯卧位显著降低了平均三维矢量位移（1.1±0.6（Pr） vs. 2.0±0.9 mm（Su），p<0.01）及其变异性（0.3±0.2 vs. 0.5±0.3 mm，p = 0.01）。Pr位呼吸引起的CW体积变化也显著更低（2.3±4.9 vs. 9.6±7.1 cm³，p<0.01）。Pr位的CW/H-V显著小于Su位（39.9±14.6 vs. 64.3±28.2 cm³，p<0.01）。除了靶区覆盖相同外，与Pr-noC、Su-C和Su-noC相比，Pr-C时左前降支冠状动脉（LADCA）和同侧肺的剂量参数降低。俯卧位显著减少了与呼吸相关的手术夹运动、其变异性以及CW运动。在Pr位观察到心脏明显的前向位移。每日在线校正的俯卧位可最大限度地保护心脏和LADCA。
