保留活性骨髓(ABM)可以减少宫颈癌放化疗患者的急性血液学毒性,但是基于正电子发射断层扫描/计算机断层扫描(PET/CT)的ABM分割成本很高。我们试图开发一种基于图谱的ABM分割方法,以在前瞻性临床试验中实施。
多图谱建立在144名患者的训练集上,并在NRG-GY006临床试验的32名患者中进行了验证。个别患者的ABM被定义为骨盆骨亚体积大于注册的18F-脱氧葡萄糖PET/CT图像上的个体平均标准化摄取值。使用Dice相似性系数和平均距离比较了基于Atlas的ABM分割和自定义ABM分割,以达成一致,并用于生成ABM保留强度调制放射治疗计划。使用线性回归比较两种方法的剂量体积指标和正常组织并发症概率。
基于Atlas的ABM卷(平均值[标准偏差],548.4[88.3]cm3)略大于定制ABM体积(535.1[93.2]cm3),Dice相似系数为0.73。使用基于定制的计划,总骨盆骨髓V20和Dmean系统较高,而定制ABMV10系统较低(斜率:1.021[95%置信区间(CI),1.005-1.037],1.014[95%CI,1.006-1.022],和0.98[95%CI,0.97-0.99],分别)。我们发现基于图谱和基于定制的肠道计划之间没有显着差异,直肠,膀胱,股骨头,或目标剂量-体积指标。
基于Atlas的ABM分割可以减少骨盆骨髓剂量,同时实现与其他正常组织剂量相当的目标。这种方法可以允许ABM在PET/CT不可用的设置中节省。
Sparing active bone marrow (ABM) can reduce acute hematologic toxicity in patients undergoing chemoradiotherapy for cervical cancer, but ABM segmentation based on positron emission tomography/computed tomography (PET/CT) is costly. We sought to develop an atlas-based ABM segmentation method for implementation in a prospective clinical
trial.
A multiatlas was built on a training set of 144 patients and validated in 32 patients from the NRG-GY006 clinical
trial. ABM for individual patients was defined as the subvolume of pelvic bone greater than the individual mean standardized uptake value on registered 18F-fluorodeoxyglucose PET/CT images. Atlas-based and custom ABM segmentations were compared using the Dice similarity coefficient and mean distance to agreement and used to generate ABM-sparing intensity modulated radiation therapy plans. Dose-volume metrics and normal tissue complication probabilities of the two approaches were compared using linear regression.
Atlas-based ABM volumes (mean [standard deviation], 548.4 [88.3] cm3) were slightly larger than custom ABM volumes (535.1 [93.2] cm3), with a Dice similarity coefficient of 0.73. Total pelvic bone marrow V20 and Dmean were systematically higher and custom ABM V10 was systematically lower with custom-based plans (slope: 1.021 [95% confidence interval (CI), 1.005-1.037], 1.014 [95% CI, 1.006-1.022], and 0.98 [95% CI, 0.97-0.99], respectively). We found no significant differences between atlas-based and custom-based plans in bowel, rectum, bladder, femoral heads, or target dose-volume metrics.
Atlas-based ABM segmentation can reduce pelvic bone marrow dose while achieving comparable target and other normal tissue dosimetry. This approach may allow ABM sparing in settings where PET/CT is unavailable.