Chen Chia-Hsin, Hsieh Ching-Chuan, Chang Chih-Shen, Chen Miao-Fen
Department of Radiation Oncology, Chang Gung Memorial Hospital, Chiayi, Taiwan.
Department of General Surgery, Chang Gung Memorial Hospital, Chiayi, Taiwan.
Cancer Manag Res. 2020 Sep 28;12:9173-9182. doi: 10.2147/CMAR.S269893. eCollection 2020.
A better understanding of the organs-at-risk (OAR) dose metrics and the related toxicity induced by radiotherapy (RT) for left breast cancer (BC) will improve the quality of life. This study addressed the issue for left-BC patients treated with intensity-modulated radiotherapy (IMRT) compared to three-dimensional conformal radiotherapy (3D-CRT).
Between 2012 and 2018, 308 left-BC patients underwent adjuvant RT at our hospital. Before June 2015, 134 patients were treated with 3D-CRT. Thereafter, 174 patients underwent IMRT. The patient's characteristics in the IMRT group did not significantly different compared to those in the 3D-CRT group.
Among the total study population, the incidence of ≥grade 2 radiation dermatitis (RID) was 17.3%. Higher volumes receiving 105% (≥5.7%) and 107% (≥1%) of prescribed dose and 3D-CRT technique were associated with a higher risk of RID. Regarding lung toxicity, the mean lung dose (≥10.2Gy) and V20 (≥20%) of ipsilateral lung were significantly associated with the incidence of RT-induced pulmonary changes. By dosimetry analysis, IMRT achieved better dose conformity and delivered lower mean doses to heart and ipsilateral lung compared to 3D-CRT. Furthermore, propensity sore and multivariate analysis showed that IMRT technique helped to reduce RT-induced dermatitis and lung toxicity.
Our data suggest that the volume of OAR exposed to higher doses is a predictor of RT-induced toxicity. Adjuvant RT with IMRT technique offered better dose conformity and spared high-dose levels to OARs to reduce radiation-related morbidity for BC patients.
更好地了解左乳腺癌（BC）放疗（RT）的危及器官（OAR）剂量指标及相关毒性将改善生活质量。本研究探讨了与三维适形放疗（3D-CRT）相比，接受调强放疗（IMRT）的左BC患者的这一问题。
2012年至2018年期间，我院308例左BC患者接受了辅助放疗。2015年6月之前，134例患者接受3D-CRT治疗。此后，174例患者接受IMRT治疗。IMRT组患者的特征与3D-CRT组相比无显著差异。
在整个研究人群中，≥2级放射性皮炎（RID）的发生率为17.3%。接受105%（≥5.7%）和107%（≥1%）处方剂量的较高体积以及3D-CRT技术与更高的RID风险相关。关于肺部毒性，同侧肺的平均肺剂量（≥10.2Gy）和V20（≥20%）与放疗引起的肺部改变发生率显著相关。通过剂量学分析，与3D-CRT相比，IMRT实现了更好的剂量适形性，并向心脏和同侧肺输送了更低的平均剂量。此外，倾向评分和多因素分析表明，IMRT技术有助于降低放疗引起的皮炎和肺部毒性。
我们的数据表明，暴露于较高剂量的OAR体积是放疗引起毒性的一个预测指标。采用IMRT技术的辅助放疗提供了更好的剂量适形性，并使OAR免受高剂量照射，以降低BC患者的放射性发病率。
