Huang Eng-Yen, Ho Meng Wei, Wang Yu-Ming
Department of Radiation Oncology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Proton and Radiation Therapy Center, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
J Breast Cancer. 2024 Jun;27(3):187-200. doi: 10.4048/jbc.2024.0012. Epub 2024 Apr 15.
Pencil-beam scanning (PBS) is a modern delivery technique used in proton beam therapy (PBT) to reduce normal tissue reactions. No dosimetric correlation between dermatitis and PBS has been reported for breast cancer. The current study aimed to investigate the factors associated with grade 2 or higher dermatitis in patients with breast cancer undergoing PBT using PBS.
The medical data of 42 patients with breast cancer who underwent adjuvant radiotherapy between December 2019 and September 2023 were reviewed. All patients received hypofractionated radiotherapy (HFRT), either 26 Gy (relative biological effectiveness [RBE])/five fractions or 40.05 or 43.5 Gy (RBE)/15 fractions, for the whole breast/chest wall with or without nodal irradiation. The duration of acute radiation dermatitis was defined as within 90 days from the start of radiotherapy. The Kaplan-Meier method and Cox proportional hazards model were used for univariate and multivariate analyses of the actuarial rates of grade 2-3 dermatitis.
Twenty-two (52.4%) and 20 (47.6%) patients were diagnosed with grade 1 and 2 dermatitis, respectively. Multivariate analysis revealed a clinical target volume (CTV) ≥ of 320 cc ( = 0.035) and a skin dose of D ≥ 38.3 Gy (RBE) ( = 0.009) as independent factors of grade 2 dermatitis. The 10-week cumulative grade 2 dermatitis rates were 88.2%, 39.4%, and 8.3% ( < 0.001) for patients with both high, either high, and neither high CTV and D, respectively.
To the best of our knowledge, this is the first study on dosimetric correlations for dermatitis in patients with breast cancer who underwent hypofractionated PBT using PBS. In the era of HFRT, skin dose modulation using PBS may reduce the incidence of dermatitis.
笔形束扫描（PBS）是质子束治疗（PBT）中使用的一种现代放疗技术，用于减少正常组织反应。目前尚无关于乳腺癌患者皮炎与PBS之间剂量学相关性的报道。本研究旨在调查接受PBS-PBT的乳腺癌患者中与2级或更高级别皮炎相关的因素。
回顾了2019年12月至2023年9月期间接受辅助放疗的42例乳腺癌患者的医疗数据。所有患者均接受了大分割放疗（HFRT），全乳/胸壁照射剂量为26 Gy（相对生物效应[RBE]）/5次分割或40.05或43.5 Gy（RBE）/15次分割，部分患者还接受了区域淋巴结照射。急性放射性皮炎的持续时间定义为放疗开始后90天内。采用Kaplan-Meier法和Cox比例风险模型对2-3级皮炎的精算发生率进行单因素和多因素分析。
分别有22例（占52.4%）和20例（占47.6%）患者被诊断为1级和2级皮炎。多因素分析显示，临床靶体积（CTV）≥320 cc（P = 0.035）和皮肤剂量D≥38.3 Gy（RBE）（P = 0.009）是2级皮炎的独立影响因素。CTV和D均高、仅其中一项高以及两者均不高的患者，其10周累积2级皮炎发生率分别为88.2%、39.4%和8.3%（P < 0.001）。
据我们所知，这是第一项关于接受PBS-HFRT的乳腺癌患者皮炎剂量学相关性的研究。在HFRT时代，使用PBS进行皮肤剂量调制可能会降低皮炎的发生率。
