早期左侧乳腺癌保乳术后大分割放疗同期瘤床加量的安全性及心脏亚结构剂量评估的重要性研究

doi:10.19401/j.cnki.1007-3639.2022.05.008

摘要/Abstract

摘要：

背景与目的： 早期乳腺癌保乳术后辅助大分割放疗已被指南推荐,但大分割放疗同期瘤床加量是否可行目前尚无定论。本随机对照研究对大分割同期瘤床加量和常规分割同期瘤床加量两种放疗计划的心脏剂量学参数和心超指标等进行比较,以评估前者在心脏毒性方面的安全性。方法： 纳入复旦大学附属中山医院2017年3月—2018年3月收治的符合入组标准的早期乳腺癌保乳术后左侧乳腺癌患者40例,随机分为两组,20例制定大分割同期瘤床加量放疗计划（全乳放疗剂量4 005 cGy/15次,同期瘤床加量至4 500 cGy/15次）,20例制定常规分割同期瘤床加量放疗计划（全乳放疗剂量5 000 cGy/25次,同期瘤床加量至6 000 cGy/25次）,比较两组患者的心脏剂量学参数和心脏超声检查指标,剂量学参数包括全心脏、左心室、右心室、右室游离壁、室间隔和冠状动脉左前降支（left anterior descending,LAD）的平均剂量（D_mean）以及各结构受到5~35 Gy照射的相对体积分数（V_{5 Gy}~V_{35 Gy}）。心超随访指标包括主动脉根部直径、左房内径、左室舒张末内径、左室收缩末内径、室间隔厚度、左室后壁厚度、肺动脉收缩压、左室射血分数、E峰、A峰、E峰减速时间（E-peak deceleration time,DT）、E、A、E/A和S波峰值。此外,对两组放疗后乳房的美容效果也进行评估。结果： 大分割组和常规分割组全心脏的D_mean分别为（471.86±170.54）和（733.07±79.11）cGy（P<0.05）,全心脏的V_{20 Gy}为（3.63±1.74）%和（8.43±0.74）%（P <0.05）,V_{30 Gy}为（1.55±1.15）%和（4.48±1.01）%（P<0.05）,LAD的D_mean分别为（1 250.17±600.33）和（1 847.20±933.23）cGy（P>0.05）,左心室的D_mean分别（908.64±865.60）和（946.93±116.13）cGy（P>0.05）,右心室的D_mean分别为（590.37±197.99）和（905.73±180.82）cGy（P<0.05）,右室游离壁的D_mean分别为（939.40±284.23）和（1 597.30±446.31）cGy（P <0.05）,室间隔的D_mean分别为（637.49±248.19）和（988.60±159.77）cGy（P<0.05）。随访1年,大分割组与常规分割组相比,心超指标均在正常区间,差异均无统计学意义（P>0.05）。两组美容效果也无显著差异（P>0.05）。结论： 大分割同期瘤床加量放疗计划较常规分割计划可以显著降低全心脏和部分心脏亚结构的受照剂量,随访1年心超指标无异常,临床采用本研究所用的剂量分割方式是安全可行的。仅限制全心脏剂量无法有效保护LAD,建议勾画心脏亚结构并单独限制剂量以更好地保护心脏。

关键词: 早期乳腺癌, 保乳术后, 大分割放疗, 同步瘤床加量, 心脏损伤

Abstract:

Background and purpose: Adjuvant radiotherapy for breast cancer after early breast-conserving surgery has been recommended by the guidelines. However, the feasibility of hypofractionated radiotherapy with simultaneous integrated boost is not available. In this randomized controlled study, the cardiac dosimetry parameters and cardiac ultrasound indexes of the two radiotherapy plans were compared to evaluate the safety of hypofractionated radiotherapy with simultaneous integrated boost plan in terms of cardiotoxicity. Methods: A total of 40 patients with breast cancer who received breast-conserving surgery were selected in Zhongshan Hospital, Fudan University from March 2017 to March 2018. They were randomly divided into two groups, including 20 patients reveiving hypofractionated radiotherapy with simultaneous integrated boost plan (whole breast 4 005 cGy/15 Fx, tumor bed 4 500 cGy/15 Fx) and 20 patients reveiving conventional fractionation with simultaneous integrated boost plan (whole breast 5 000 cGy/25 Fx, tumor bed 6 000 cGy/25 Fx). The cardiac dosimetric parameters and cardiac ultrasound indexes of the two groups were compared. The dosimetric parameters included the average doses (D_mean) of the whole heart, left ventricle, right ventricle, right ventricular free wall, ventricular septum and left anterior descending (LAD) coronary artery, and the relative volume fraction of each structure irradiated by 5-35 Gy (V_{5 Gy}-V_{35 Gy}). The follow-up indexes of echocardiography included aortic root diameter, left atrial diameter, left ventricular end diastolic diameter, left ventricular end systolic diameter, ventricular septal thickness, left ventricular posterior wall thickness, pulmonary artery systolic pressure, left ventricular ejection fraction, E peak, A peak, E-peak deceleration time (DT), E, A, E/A and S wave peak. In addition, the cosmetic effect on breast after radiotherapy in the two groups was also evaluated. Results: D_mean of the whole heart in the hypofractionated group and the conventional group were (471.86±170.54) and (733.07±79.11) cGy (P<0.05); V_{20 Gy} of the whole heart was (3.63±1.74) and (8.43±0.74)% (P<0.05), and V30 Gy was (1.55±1.15) and (4.48±1.01)% (P<0.05). D_mean of LAD were (1 250.17±600.33) and (1 847.20±933.23) cGy (P>0.05); D_mean of left ventricle were (908.64±865.60) vs (946.93±116.13) cGy (P>0.05). D_mean of right ventricle were (590.37±197.99) vs (905.73±180.82) cGy (P<0.05); D_mean of right ventricular free wall were (939.40±284.23) vs (1 597.30±446.3) cGy (P<0.05); D_mean of ventricular septum were (1 637.49±248.19) vs (988.60±159.77) cGy (P<0.05). After one year of follow-up, the cardiac ultrasound indexes in the hypofractionated group and the conventional group were in the normal range, and there was no significant difference between the two groups (P>0.05). There was no significant difference in cosmetic effect between the two groups (P>0.05). Conclusion: Compared with the conventional fractionation plan, hypofractionated radiotherapy with simultaneous integrated boost significantly reduced the radiation dose of the whole heart and some cardiac substructures, and there were no abnormal cardiac ultrasound indexes during one-year follow-up. The dose fractionation method in this study is safe and feasible. Limiting the whole heart dose alone can not effectively protect LAD, so it is recommended to outline the cardiac substructure and limit the dose alone to better protect the heart.

Key words: Early breast cancer, Breast-conserving surgery, Hypofractionated radiotherapy, Simultaneous integrated boost, Cardiac injury

中图分类号:

R737.9

章倩, 方晓燕, 刘娟, 刘进, 程蕾蕾, 孙菁. 早期左侧乳腺癌保乳术后大分割放疗同期瘤床加量的安全性及心脏亚结构剂量评估的重要性研究[J]. 中国癌症杂志, 2022, 32(5): 427-435.

ZHANG Qian, FANG Xiaoyan, LIU Juan, LIU Jin, CHENG Leilei, SUN Jing. Study on the safety of simultaneous integrated boost and the importance of cardiac substructural dose assessment of hypofractionated radiotherapy after early left breast cancer breast-conserving surgery[J]. China Oncology, 2022, 32(5): 427-435.

图/表 4

表1

表2

两组患者的正常组织剂量-体积参数比较"

Item	Hypofractionated group	Conventional group	P value
Heart D_mean/cGy	471.86±170.54	733.07±79.11	0.027
Heart D_max/cGy	3 960.16±126.66	5 007.90±246.57	0.000
Heart D_min/cGy	62.32±22.82	96.17±35.51	0.063
Heart V_{5 Gy} /%	27.61±20.64	42.50±8.29	0.256
Heart V_{10 Gy} /%	11.46±8.41	18.72±4.59	0.184
Heart V_{20 Gy} /%	3.63±1.74	8.43±0.74	0.000
Heart V_{25 Gy} /%	2.45±1.44	6.12±0.85	0.002
Heart V_{30 Gy} /%	1.55±1.15	4.48±1.01	0.002
Heart V_{35 Gy} /%	0.70±0.64	3.05±0.98	0.000
Heart V_{50 Gy} /%	0.00±0.00	0.01±0.01	0.423
LAD D_mean /cGy	1 250.17±600.33	1 847.20±933.23	0.195
LAD V_{5 Gy} /%	67.70±24.38	89.52±9.00	0.163
LAD V_{10 Gy} /%	42.24±28.35	74.32±2.36	0.082
Left ventricle D_max/cGy	3 964.88±303.46	4 875.67±174.51	0.000
Left ventricle D_min /cGy	89.11±22.75	151.27±40.85	0.004
Left ventricle D_mean /cGy	908.64±865.60	946.93±116.13	0.942
Left ventricle V_{5 Gy} /%	47.19±22.09	54.73±6.44	0.58
Left ventricle V_{10 Gy} /%	23.59±21.99	29.12±9.07	0.685
Left ventricle V_{30 Gy} /%	9.63±3.75	6.31±2.89	0.818
Right ventricle D_max /cGy	3 730.65±381.30	4 638.93±107.23	0.002
Right ventricle D_min /cGy	142.23±71.05	154.37±19.47	0.780
Right ventricle D_mean /cGy	590.37±197.99	905.73±180.82	0.029
Right ventricle V_{5 Gy} /%	39.68±26.10	55.26±14.81	0.350
Right ventricle V_{10 Gy} /%	12.92±8.52	24.57±9.55	0.062
Right ventricle V_{30 Gy} /%	1.44±0.86	6.17±1.98	0.002
Right ventricular free wall D_max /cGy	3 854.95±197.13	4 640.00±109.46	0.000
Right ventricular free wall D_min /cGy	196.37±99.91	214.70±74.34	0.775
Right ventricular free wall D_mean /cGy	939.40±284.23	1 597.30±446.31	0.008
Right ventricular free wall V_{5 Gy} /%	58.05±23.43	82.22±16.03	0.123
Right ventricular free wall V_{10 Gy} /%	28.68±13.55	46.48±14.26	0.069
Right ventricular free wall V_{30 Gy} /%	5.60±3.29	21.60±8.89	0.002
Ventricular septum D_max /cGy	3 357.73±674.33	4 545.83±123.14	0.012
Ventricular septum D_min /cGy	158.70±103.14	156.17±25.98	0.968
Ventricular septum D_mean /cGy	637.49±248.19	988.60±159.77	0.041
Ventricular septum V_{5 Gy}/%	41.64±27.56	52.79±9.09	0.514
Ventricular septum V_{10 Gy}/%	17.06±13.97	32.48±11.55	0.107
Ventricular septum V_{30 Gy}/%	1.57±0.25	6.50±1.67	0.004
Ipsilateral lung D_max /cGy	4 211.42±174.87	5 347.97±578.57	0.073
Ipsilateral lung D_min /cGy	29.35±10.41	42.77±7.25	0.061
Ipsilateral lung D_mean /cGy	656.23±148.58	1 039.27±199.52	0.003
Ipsilateral lung V_{20 Gy}/%	10.65±3.53	17.39±3.90	0.014
Contralateral breast D_mean /cGy	168.52±78.54	292.27±95.21	0.038

表2

表3

两组患者的心超指标比较"

Item	Hypofractionated group	Conventional group	P value
Aortic root diameter (before radiotherapy) D/mm	29.60±1.26	31.33±0.57	0.056
Aortic root diameter (after radiotherapy) D/mm	28.60±1.17	28.33±1.53	0.751
Aortic root diameter (1 year after radiotherapy) D/mm	29.70±1.41	30.33±2.31	0.564
Left atrial diameter (before radiotherapy) D/mm	33.60±4.09	32.00±2.00	0.535
Left atrial diameter (after radiotherapy) D/mm	34.50±3.92	33.00±1.00	0.537
Left atrial diameter (1 year after radiotherapy) D/mm	32.70±4.29	32.33±1.53	0.890
Left ventricular end diastolic diameter (before radiotherapy) D/mm	44.80±3.74	44.33±1.15	0.839
Left ventricular end diastolic diameter (after radiotherapy) D/mm	44.90±2.42	44.67±1.53	0.880
Left ventricular end diastolic diameter (1 year after radiotherapy) D/mm	42.80±2.15	44.67±0.58	0.176
Left ventricular end systolic diameter (before radiotherapy) D/mm	28.30±3.65	27.33±0.58	0.440
Left ventricular end systolic diameter (after radiotherapy) D/mm	28.10±2.02	27.67±1.53	0.741
Left ventricular end systolic diameter (1 year after radiotherapy) D/mm	27.10±2.18	29.33±2.31	0.152
Ventricular septal thickness (before radiotherapy) D/mm	9.00±1.41	8.33±0.58	0.453
Ventricular septal thickness (after radiotherapy) D/mm	8.40±1.26	9.00±1.00	0.471
Ventricular septal thickness (1 year after radiotherapy) D/mm	9.40±0.84	9.33±1.15	0.913
Left ventricular posterior wall thickness (before radiotherapy) D/mm	8.50±1.27	8.00±1.00	0.548
Left ventricular posterior wall thickness (after radiotherapy) D/mm	8.20±0.92	8.33±1.52	0.851
Left ventricular posterior wall thickness (1 year after radiotherapy) D/mm	9.00±0.82	8.67±1.53	0.617
Pulmonary artery systolic pressure (before radiotherapy)/mmHg	29.50±4.25	24.00±4.58	0.079
Pulmonary artery systolic pressure (after radiotherapy)/mmHg	27.90±5.36	27.33±3.21	0.868
Pulmonary artery systolic pressure (1 year after radiotherapy)/mmHg	27.10±3.54	35.00±12.28	0.381
Left ventricular ejection fraction (before radiotherapy)/%	65.30±5.96	68.33±1.53	0.414
Left ventricular ejection fraction (after radiotherapy)/%	67.20±3.22	68.33±4.16	0.624
Left ventricular ejection fraction (1 year after radiotherapy)/%	66.20±4.96	63.33±6.43	0.425
E peak (before radiotherapy)	70.06±11.81	71.27±10.58	0.877
E peak (after radiotherapy)	56.55±6.67	69.07±7.10	0.451
E peak (1 year after radiotherapy)	72.06±7.22	70.00±3.61	0.845
A peak (before radiotherapy)	69.60±18.46	61.70±20.36	0.537
A peak (after radiotherapy)	48.15±17.07	63.17±15.33	0.387
A peak (1 year after radiotherapy)	66.69±15.51	60.00±19.05	0.544
DT (before radiotherapy) t/ms	164.30±19.95	136.67±21.50	0.062
DT (after radiotherapy) t/ms	139.6±57.95	172.33±57.27	0.408
DT (1 year after radiotherapy) t/ms	157.00±37.28	149.00±26.51	0.739
E (before radiotherapy)	12.17±3.12	7.77±1.24	0.051
E (after radiotherapy)	10.25±4.87	8.2±1.04	0.496
E (1 year after radiotherapy)	10.90±3.41	9.97±3.07	0.681
A (before radiotherapy)	10.89±2.44	9.43±0.25	0.338
A (after radiotherapy)	8.47±3.45	9.50±0.35	0.626
A (1 year after radiotherapy)	9.88±2.82	8.83±1.42	0.557
S wave peak (before radiotherapy) / (cm · s^-1)	11.15±2.81	11.73±1.88	0.746
S wave peak (after radiotherapy) / (cm · s^-1)	8.22±3.28	11.10±0.85	0.172
S wave peak (1 year after radiotherapy) / (cm · s^-1)	10.05±1.99	9.57±0.84	0.696

表3

表4

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Item	Hypofractionated group	Conventional group	P value
Age/year			0.33
<60	19	20
≥60	1	0
Hypertension			0.33
Yes	1	0
No	19	20
Dyslipidemia			0.33
Yes	1	0
No	19	20
Diabetes			0.33
Yes	1	0
No	19	20
Pathological stage			0.757
Ⅰ	9	8
Ⅱ	11	12
Grade			0.48
1-2	17	18
3	3	2
Vascular tumor thrombus			0.33
Yes	0	1
No	20	19
Chemotherapy			0.55
Anthracycline drugs	4	2
Taxus drugs	4	6
Anthracycline + Taxus drugs	7	8
No	5	4
Targeted therapy			0.16
Trastuzumab	2	0
No	0	0

Item	Before radiotherapy	After radiotherapy	1 year after radiotherapy	P value
Item	Before radiotherapy	After radiotherapy	1 year after radiotherapy	Before radiotherapy vs after radiotherapy	Before radiotherapy vs 1 year after radiotherapy	After radiotherapy vs 1 year after radiotherapy
Aortic root diameter D/mm	29.50±3.34	29.50±2.97	29.65±2.17	0.992	0.902	0.881
Left atrial diameter D/mm	33.23±3.70	33.56±3.48	32.62±3.78	0.435	0.294	0.065
Left ventricular end diastolic diameter D/mm	44.69±3.28	44.85±2.19	43.23±2.05	0.824	0.123	0.185
Left ventricular end systolic diameter D/mm	28.08±3.20	28.00±1.87	27.62±2.33	0.92	0.654	0.641
Ventricular septal thickness D/mm	8.85±1.28	8.53±1.20	9.38±0.87	0.367	0.017	0.009
Left ventricular posterior wall thickness D/mm	8.38±1.19	8.23±1.01	8.92±0.95	0.549	0.11	0.022
Pulmonary artery systolic pressure/mmHg	28.23±4.78	27.77±4.83	28.92±6.82	0.82	0.753	0.636
Left ventricular ejection fraction/%	65.83±5.37	66.06±3.31	64.50±5.19	0.506	0.537	0.514
E peak	70.34±11.12	59.44±23.93	71.58±15.01	0.228	0.796	0.201
A peak	67.78±18.35	51.62±25.14	65.15±15.80	0.094	0.636	0.137
DT t/ms	157.92±22.86	147.15±57.20	155.15±34.23	0.519	0.808	0.602
E	11.15±3.36	9.77±4.33	10.68±3.24	0.141	0.627	0.45
A	10.55±2.20	8.71±3.02	9.63±2.55	0.159	0.311	0.515
E/A	1.10±0.33	1.22±0.39	1.16±0.37	0.193	0.501	0.478
S wave peak/(cm · s^-1)	11.28±2.57	8.88±3.13	9.94±1.77	0.058	0.187	0.344