Respiratory Division.
Department of Radiotherapy.
Int J Radiat Oncol Biol Phys. 2022 Jul 1;113(3):561-569. doi: 10.1016/j.ijrobp.2022.02.021. Epub 2022 Feb 25.
Previous studies in patients with breast cancer have shown acute radiation therapy-induced reductions of pulmonary diffusing capacity, essentially owing to lung volume restriction. We aimed to assess the long-term effect of 2 radiation therapy regimens, which differed in terms of radiation technique and dose fractionation, on lung function.
From a randomized controlled trial comparing conventional 3-dimensional conformal radiation therapy (CR) and hypofractionated tomotherapy (TT), 84 patients with breast cancer (age at inclusion 54 ± 10 [standard deviation] years) could be assessed at baseline, after 3 months, and after 1, 2, 3, and 10 years. Measurements included forced vital capacity, total lung capacity (TLC), and diffusing capacity (TLco).
Radiation therapy-induced lung function changes over 10 years (Δ) were similar for both treatment arms, and in a patient subgroup with negligible history of respiratory disease or smoking (n = 57) these averaged: Δ forced vital capacity = -13 (± 9) percent predicted; ΔTLco = -14 (± 12) percent predicted; and ΔTLC = -11 (± 9) percent predicted. The only significant correlation was between V20 (lung volume exposed to dose exceeding 20 Gy) and ΔTLco (rho = -0.36; P = .007). In this subgroup, as well as in the entire patient cohort, the incurred pulmonary restriction in terms of TLC and TLco showed a greater decline at 3 months for CR versus TT. However, at 10 years, no significant difference could be detected between CR and TT (P = .9 for TLC and P = .2 for TLco in the entire patient cohort). Of the patients with normal TLC and TLco at baseline (ie, above lower limits of normal), respectively 94% and 96% were still normal 10 years later.
In women with breast cancer, conventional 3-dimensional conformal radiation therapy and hypofractionated tomotherapy induce similar restrictive lung patterns during the course of a 10-year period, despite some treatment-dependent differences in the first 3 months. The large majority of women with normal lung function at baseline maintained a normal lung function status 10 years after radiation therapy, irrespective of treatment arm.
之前对乳腺癌患者的研究表明，急性放射治疗可导致肺弥散量降低，主要是由于肺容积受限。我们旨在评估两种放射治疗方案的长期效果，这两种方案在放射技术和剂量分割方面有所不同，对肺功能的影响。
从一项比较常规三维适形放射治疗（CR）和低分割托姆治疗（TT）的随机对照试验中，我们可以评估 84 名乳腺癌患者（纳入时年龄 54 ± 10 [标准差] 岁）在基线、3 个月后以及 1、2、3 和 10 年后的情况。测量包括用力肺活量、总肺容量（TLC）和弥散量（TLco）。
10 年内放射治疗引起的肺功能变化（Δ）在两种治疗组中相似，在无明显呼吸疾病或吸烟史的患者亚组（n = 57）中，这些平均值为：Δ用力肺活量 = -13（±9）%预计值；ΔTLco = -14（±12）%预计值；ΔTLC = -11（±9）%预计值。唯一的显著相关性是 V20（肺体积暴露于剂量超过 20 Gy）与ΔTLco（rho = -0.36；P = 0.007）之间的相关性。在这个亚组以及整个患者队列中，与 TT 相比，CR 在 3 个月时引起的 TLC 和 TLco 的肺限制更为明显。然而，在 10 年时，CR 和 TT 之间没有发现显著差异（整个患者队列中 TLC 的 P = 0.9 和 TLco 的 P = 0.2）。在基线时 TLC 和 TLco 正常的患者中（即高于正常值下限），分别有 94%和 96%在 10 年后仍正常。
在乳腺癌患者中，常规三维适形放射治疗和低分割托姆治疗在 10 年期间引起相似的限制性肺模式，尽管在最初的 3 个月内存在一些与治疗相关的差异。大多数基线肺功能正常的女性在放射治疗后 10 年仍保持正常的肺功能状态，无论治疗组如何。
