Maemoto Hitoshi, Toita Takafumi, Ariga Takuro, Heianna Joichi, Yamashiro Tsuneo, Murayama Sadayuki
Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215, Japan.
J Radiat Res. 2017 May 1;58(3):397-404. doi: 10.1093/jrr/rrw101.
To determine the predictive factors affecting uterine movement during radiotherapy (RT), we quantified interfraction uterine movement using computed tomography (CT) and cone-beam CT (CBCT). A total of 38 patients who underwent definitive RT for cervical cancer were retrospectively analyzed. We compared pre-RT planning CT (n = 38) and intratreatment CBCT (n = 315), measuring cervical and corporal movement in each direction. Correlations between uterine movement and volume changes of the bladder and rectum on all CBCT scans were analyzed using Spearman rank correlation analysis. Relationships between the mean uterine movement and patient factors were analyzed using the Mann-Whitney test. The mean corpus movement was: superior margin (cranio-caudal direction), 7.6 ± 5.9 mm; anterior margin (anteroposterior direction), 8.3 ± 6.3 mm; left margin (lateral direction), 3.3 ± 2.9 mm; and right margin (lateral direction), 3.0 ± 2.3 mm. Generally, the mean values for cervical movement were smaller than those for the corpus. There was a significant, weak correlation between changes in bladder volume and the movement of the superior margin of the corpus (ρ = 0.364, P < 0.001). There was a significant difference in movement of the superior margin of the corpus between the subgroups with and without a history of previous pelvic surgery (P = 0.007). In conclusion, change in bladder volume and a history of previous surgery were significantly related to intrafractional corpus movement; however, our observations suggest that the accurate prediction of uterine movement remains challenging.
为了确定影响放疗（RT）期间子宫运动的预测因素，我们使用计算机断层扫描（CT）和锥形束CT（CBCT）对分次间子宫运动进行了量化。对38例接受宫颈癌根治性放疗的患者进行了回顾性分析。我们比较了放疗前计划CT（n = 38）和治疗期间CBCT（n = 315），测量了每个方向上宫颈和宫体的运动。使用Spearman等级相关分析对所有CBCT扫描上子宫运动与膀胱和直肠体积变化之间的相关性进行了分析。使用Mann-Whitney检验分析了平均子宫运动与患者因素之间的关系。宫体的平均运动为：上缘（头-尾方向），7.6±5.9mm；前缘（前后方向），8.3±6.3mm；左缘（外侧方向），3.3±2.9mm；右缘（外侧方向），3.0±2.3mm。一般来说，宫颈运动的平均值小于宫体运动的平均值。膀胱体积变化与宫体上缘运动之间存在显著的弱相关性（ρ = 0.364，P < 0.001）。有盆腔手术史和无盆腔手术史的亚组之间宫体上缘运动存在显著差异（P = 0.007）。总之，膀胱体积变化和既往手术史与分次间宫体运动显著相关；然而，我们的观察结果表明，准确预测子宫运动仍然具有挑战性。
