Trampetti I, Cuenin M, Gérard K, Salleron J, Peiffert D, Charra-Brunaud C
Département de radiothérapie, institut de cancérologue de Lorraine, 6, avenue de Bourgogne, 54519 Vandoeuvre-lès-Nancy, France; Faculté de médecine de Nancy, université de Lorraine, 9, avenue de la Forêt de Haye, 54505 Vandoeuvre-lès-Nancy, France.
Département de radiothérapie, institut de cancérologue de Lorraine, 6, avenue de Bourgogne, 54519 Vandoeuvre-lès-Nancy, France.
Cancer Radiother. 2023 Sep;27(5):407-412. doi: 10.1016/j.canrad.2023.06.004. Epub 2023 Aug 3.
Deep inspiration breath hold (DIBH) is used to decrease the dose of radiotherapy delivered to the heart. There is a need to define criteria to select patients with the potential to derive a real clinical benefit from DIBH treatment. Our study's main goal was to investigate whether two CT-scan cardiac anatomical parameters, cardiac contact distance in the parasagittal plane (CCDps) and lateral heart-to-chest distance (HCD), were predictive of unmet dosimetric cardiac constraints for left breast and regional nodal irradiation (RNI).
This retrospective single-institution dosimetric study included 62 planning CT scans of women with left-sided breast cancer (BC) from 2016 to 2021. Two independent radiation oncologists measured HCD and CCDps twice to assess inter- and intra-observer reproducibility. Dosimetric constraints to be respected were defined, and dosimetric parameters of interest were collected for each patient.
Mean heart dose was 7.9Gy. Inter-rater reproducibility between the two readers was considered excellent. The mean heart dose constraint<8Gy was not achieved in 25 patients (40%) and was achieved in 37 patients (60%). There was a significant correlation between mean heart dose and HCD (r=-0.25, P=0.050) and between mean heart dose and CCDps (r=0.25, P=0.047). The correlation between HCD and CCDps and unmet cardiac dosimetric constraints was not statistically significant.
Our dosimetric analysis did not find that the cardiac anatomical parameters HCD and CCDps were predictive of unmet dosimetric cardiac constraints, nor that they were good predictors for cardiac exposure in left-sided BC radiotherapy comprising RNI.
深吸气屏气（DIBH）用于减少输送至心脏的放射治疗剂量。需要定义标准以选择有可能从DIBH治疗中获得实际临床益处的患者。我们研究的主要目标是调查两个CT扫描心脏解剖参数，即矢状旁平面心脏接触距离（CCDps）和心脏至胸壁外侧距离（HCD），是否可预测左侧乳腺癌和区域淋巴结照射（RNI）时未满足的心脏剂量学限制。
这项回顾性单机构剂量学研究纳入了2016年至2021年期间62例左侧乳腺癌（BC）女性患者的计划CT扫描图像。两名独立的放射肿瘤学家对HCD和CCDps进行了两次测量，以评估观察者间和观察者内的可重复性。定义了需要遵守的剂量学限制，并收集了每位患者的相关剂量学参数。
平均心脏剂量为7.9Gy。两位读者之间的评分者间可重复性被认为是优秀的。25例患者（40%）未达到平均心脏剂量限制<8Gy，37例患者（60%）达到了该限制。平均心脏剂量与HCD之间存在显著相关性（r = -0.25，P = 0.050），与CCDps之间也存在显著相关性（r = 0.25，P = 0.047）。HCD和CCDps与未满足的心脏剂量学限制之间的相关性无统计学意义。
我们的剂量学分析未发现心脏解剖参数HCD和CCDps可预测未满足的心脏剂量学限制，也未发现它们是包含RNI的左侧BC放疗中心脏受照情况的良好预测指标。
