Naoum George E, Dobinda Katrina, Yalamanchili Amulya, Ho Alexander, Yadav Poonam, Nesbit Eric, Donnelly Eric, Kocherginsky Masha, Strauss Jonathan
Department of Radiation Oncology, Northwestern University, Northwestern Memorial Hospital, Chicago, Illinois.
Biostatistics Center, Northwestern University, Northwestern Memorial Hospital, Chicago, Illinois.
Int J Radiat Oncol Biol Phys. 2025 Jun 1;122(2):249-266. doi: 10.1016/j.ijrobp.2025.01.034. Epub 2025 Feb 11.
To compare the impact of proton versus photon postmastectomy radiation therapy (PMRT) on implant-related complications.
The records of patients with breast cancer treated with mastectomy and expander and/or implant reconstruction followed by PMRT at our institution between 2011 and 2022 were reviewed. Patients were divided into 2 groups by treatment modality: proton and photon groups. All identified patients in the proton group were treated using conventional fractionation, and radiobiological effectiveness (RBE) was scaled to 1.1. Recorded complications included infection/skin necrosis requiring operative debridement, capsular contracture necessitating capsulotomy, absolute reconstruction failure implying complete loss of reconstruction, and overall reconstruction failure defined as multiple revisions leading to replacement of the implant or salvage autologous reconstruction. Subgroup analysis for patients in the proton group explored the correlation between dosimetric parameters and complications. Logistic regression and Cox proportional hazards regression models were used.
A total of 203 patients with an overall median follow-up of 4.7 years were identified. Among those 203 patients, 50 patients (25%) received proton PMRT, while 153 patients (75%) received photon PMRT. The complication rates for proton versus photon therapies were infection/necrosis (20% vs 13%; OR, 1.6; P = .2), capsular contracture (30% vs 10%; OR, 3.9; P < .001), absolute reconstruction failure (16% vs 12%; OR, 1.4; P = .4), and overall reconstruction failure (56% vs 36%; OR, 2.2; P = .01). Sensitivity analyses and time-to-event models yielded similar results. The median (Dmean) for clinical target volume, implant, and skin was 50.6, 50.8, and 6.7 Gy (RBE), respectively. The median hot spot (D1cc) for clinical target volume, implant, and skin was 52.8, 52.7, and 49.8 Gy (RBE), respectively. None of these parameters were significantly correlated with complications. The 5-year local failure cumulative incidence was 0% versus 4% (P = .13) for proton and photon cohorts, respectively.
Proton PMRT was associated with higher rates of implant capsular contracture and reconstruction failures than photon PMRT with comparable local control. No dosimetric parameter correlated with reconstruction complications.
比较质子放疗与光子放疗在乳房切除术后放疗（PMRT）中对植入物相关并发症的影响。
回顾了2011年至2022年间在我院接受乳房切除术、扩张器和/或植入物重建并随后进行PMRT的乳腺癌患者的记录。患者按治疗方式分为两组：质子组和光子组。质子组中所有确诊患者均采用常规分割放疗，放射生物学效应（RBE）按比例调整为1.1。记录的并发症包括需要手术清创的感染/皮肤坏死、需要进行囊切开术的包膜挛缩、意味着重建完全失败的绝对重建失败，以及定义为多次翻修导致植入物更换或挽救性自体重建的总体重建失败。对质子组患者进行亚组分析，探讨剂量学参数与并发症之间的相关性。使用逻辑回归和Cox比例风险回归模型。
共确定了203例患者，总体中位随访时间为4.7年。在这203例患者中，50例（25%）接受质子PMRT，153例（75%）接受光子PMRT。质子放疗与光子放疗的并发症发生率分别为：感染/坏死（20%对13%；OR，1.6；P = 0.2）、包膜挛缩（30%对10%；OR，3.9；P < 0.001）、绝对重建失败（16%对12%；OR，1.4；P = 0.4）和总体重建失败（56%对36%；OR，2.2；P = 0.01）。敏感性分析和事件发生时间模型得出了相似的结果。临床靶区、植入物和皮肤的中位（平均剂量）分别为50.6、50.8和6.7 Gy（RBE）。临床靶区、植入物和皮肤的中位热点（D1cc）分别为52.8、52.7和49.8 Gy（RBE）。这些参数均与并发症无显著相关性。质子组和光子组的5年局部失败累积发生率分别为0%和4%（P = 0.13）。
与光子PMRT相比，质子PMRT在局部控制相当的情况下，与更高的植入物包膜挛缩率和重建失败率相关。没有剂量学参数与重建并发症相关。
