目的:自2016年以来,部分乳腺照射(PBI)已成为丹麦乳腺癌组织(DBCG)针对某些乳腺癌患者的标准。在试用应计期间,在丹麦引入了呼吸门控放射治疗。本研究旨在探讨呼吸门控对平均心脏剂量(MHD)的影响。
方法:从2009年到2016年,DBCGPBI试验包括230名接受外束PBI的左侧乳腺癌患者,40Gy/15个分数/3周。在计划CT扫描上定位瘤床,使用呼吸门控,临床目标体积(CTV)的覆盖率,并收集了对有风险器官的剂量。
结果:123例患者(53%)使用了呼吸门控。在176例患者(77%)中,肿瘤床位于上部,而54例(23%)位于下部乳房象限。MHD中位数为0.37Gy(四分位距0.26-0.57Gy),0.33Gy(0.23-0.49Gy)用于呼吸门控,和0.49Gy(0.31-0.70Gy)用于自由呼吸,p<0.0001。206例(90%)MHD<1Gy,221例(96%)MHD<2Gy。呼吸门控导致上部MHD显着降低,但不适用于较低位置的肿瘤床,然而,与呼吸门控无关,所有MHD均较低.呼吸门控不能改善CTV覆盖率或降低肺剂量。
结论:PBI确保了大多数患者的低MHD。增加呼吸门控可进一步降低位于上部的肿瘤床的MHD,而不是位于下部的肿瘤床的MHD,但不会影响目标覆盖率或肺剂量。呼吸门控不再是左侧PBI的DBCG标准。
Partial breast irradiation (PBI)has beenthe Danish Breast Cancer Group(DBCG) standard for selected breast cancer patients since 2016 based onearlyresults from the DBCG PBI trial.During
trial accrual, respiratory-gated radiotherapy was introduced in Denmark. This
study aims to investigate the effect of respiratory-gating on mean heart dose (MHD).
From 2009 to 2016 the DBCG PBI
trial included 230 patientswith left-sided breast cancer receiving external beam PBI, 40 Gy/15 fractions/3 weeks.Localization of the tumor bed on the planning CT scan, the use of respiratory-gating, coverage of the clinical target volume (CTV), and doses to organs at risk were collected.
Respiratory-gating was used in 123 patients (53 %). In 176 patients (77 %) the tumor bed was in the upper and in 54 patients (23 %) in the lower breast quadrants. The median MHD was 0.37 Gy (interquartile range 0.26-0.57 Gy), 0.33 Gy (0.23-0.49 Gy) for respiratory-gating, and 0.49 Gy (0.31-0.70 Gy) for free breathing, p < 0.0001. MHD was < 1 Gy in 206 patients (90 %) and < 2 Gy in 221 patients (96 %). Respiratory-gating led to significantly lower MHD for upper-located, but not for lower-located tumor beds, however, all MHD were low irrespective of respiratory-gating. Respiratory-gating did not improve CTV coverage or lower lung doses.
PBI ensured a low MHD for most patients. Adding respiratory-gating further reduced MHD for upper-located but not for lower-located tumor beds but did not influence target coverage or lung doses. Respiratory-gating is no longer DBCG standard for left-sided PBI.