Stick Line Bjerregaard, Lorenzen Ebbe Laugaard, Yates Esben Svitzer, Anandadas Carmel, Andersen Karen, Aristei Cynthia, Byrne Orla, Hol Sandra, Jensen Ingelise, Kirby Anna M, Kirova Youlia M, Marrazzo Livia, Matías-Pérez Angela, Nielsen Mette Marie Bruun, Nissen Henrik Dahl, Oliveros Sileida, Verhoeven Karolien, Vikström Johan, Offersen Birgitte Vrou
Department of Oncology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Niels Bohr Institute, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
Clin Transl Radiat Oncol. 2021 Feb 4;27:126-131. doi: 10.1016/j.ctro.2021.01.012. eCollection 2021 Mar.
Adjuvant radiotherapy of internal mammary nodes (IMN) improves survival in high-risk early breast cancer patients but inevitably leads to more dose to heart and lung. Target coverage is often compromised to meet heart/lung dose constraints. We estimate heart and lung dose when target coverage is not compromised in consecutive patients. These estimates are used to guide the choice of selection criteria for the randomised Danish Breast Cancer Group (DBCG) Proton Trial.
179 breast cancer patients already treated with loco-regional IMN radiotherapy from 18 European departments were included. If the clinically delivered treatment plan did not comply with defined target coverage requirements, the plan was modified retrospectively until sufficient coverage was reached. The choice of selection criteria was based on the estimated number of eligible patients for different heart and lung dose thresholds in combination with proton therapy capacity limitations and dose-response relationships for heart and lung.
Median mean heart dose was 3.0 Gy (range, 1.1-8.2 Gy) for left-sided and 1.4 Gy (0.4-11.5 Gy) for right-sided treatment plans. Median V17Gy/V20Gy (hypofractionated/normofractionated plans) for ipsilateral lung was 31% (9-57%). The DBCG Radiotherapy Committee chose mean heart dose ≥ 4 Gy and/or lung V17Gy/V20Gy ≥ 37% as thresholds for inclusion in the randomised trial. Using these thresholds, we estimate that 22% of patients requiring loco-regional IMN radiotherapy will be eligible for the trial.
The patient selection criteria for the DBCG Proton Trial are mean heart dose ≥ 4 Gy and/or lung V17Gy/V20Gy ≥ 37%.
内乳淋巴结（IMN）的辅助放疗可提高高危早期乳腺癌患者的生存率，但不可避免地会增加心脏和肺部的受量。为满足心脏/肺部剂量限制，靶区覆盖范围常常受到影响。我们对连续患者在不影响靶区覆盖的情况下的心脏和肺部剂量进行了估算。这些估算结果用于指导丹麦乳腺癌协作组（DBCG）质子治疗随机试验选择标准的制定。
纳入了来自18个欧洲科室的179例已接受局部区域IMN放疗的乳腺癌患者。如果临床实施的治疗计划不符合既定的靶区覆盖要求，则对计划进行回顾性修改，直至达到足够的覆盖范围。选择标准的确定基于不同心脏和肺部剂量阈值下符合条件患者的估算数量，同时考虑质子治疗能力限制以及心脏和肺部的剂量反应关系。
左侧治疗计划的心脏平均剂量中位数为3.0 Gy（范围1.1 - 8.2 Gy），右侧为1.4 Gy（0.4 - 11.5 Gy）。同侧肺脏的V17Gy/V20Gy（大分割/常规分割计划）中位数为31%（9 - 57%）。DBCG放疗委员会选择心脏平均剂量≥4 Gy和/或肺脏V17Gy/V20Gy≥37%作为随机试验的纳入阈值。采用这些阈值，我们估计需要局部区域IMN放疗的患者中有22%符合试验条件。
DBCG质子治疗试验的患者选择标准为心脏平均剂量≥4 Gy和/或肺脏V17Gy/V20Gy≥37%。
