Fragkandrea I, Kouloulias V, Mavridis P, Zettos A, Betsou S, Georgolopoulou P, Sotiropoulou A, Gouliamos A, Kouvaris I
The Neurooncology Department, The Royal Marsden Hospital, London, UK.
Radiotherapy Department, Attikon Hospital, Athens, Greece.
Hippokratia. 2013 Jul;17(3):233-8.
Hypofractionated Radiotherapy (RT) regimens for breast cancer, although reduce cost and time for patients and health care systems, could have a negative impact on normal underlying lung tissue. We studied and compared lung function and the post-RT radiological changes using High-Resolution Computed Tomography (HRCT) in early breast cancer patients, treated with 3-Dimentional conformal whole breast radiotherapy (WBRT) using either conventional or hypofractionated regime.
Between 2008 and 2009, 61 early breast cancer patients (T1-2N0M0) were randomised into two groups .Group A (n=31) received standard radiotherapy with 50Gy/25f/5w plus boost 10Gy/5f/1w to tumour bed. Group B (n=30) received 43.2Gy/16f/22d plus boost 10Gy/5f/1w to tumour bed. Patients of both groups were subjected to dynamic lung testing, using spirometry and gas diffusion tests on Day 0 (D0, before RT), during RT and after completion of RT at 3 and 6 months. HRCT scans were performed in all patients at baseline, and 3,6,12 months after completion of RT. Respiratory symptoms were recorded at 3 and 6 months post completion of RT. Dosimetric factors, such as Central Lung Dose (CLD), lung Volume receiving more 20 Gy (V20), D25 and Mean Lung Dose (MLD) were calculated for all patients.
At 3 months after RT, the pulmonary changes were classified at HRCT as follows: 91.8 % were Grade 0, 8.19 % Grade 1, and 0 % Grade 2. At 6 months, 86.98 % were Grade 0, 11.47 % Grade 1, and 1.6 % Grade 2. At 12 months, 88.52 % were Grade 0, 9.19 % Grade 1 and 3.27% Grade 2. Univariate analysis showed strong association between radiation pneumonitis, age and all dosimetric parameters. There was no association between fractionation type and incidence of RN. FEV1, FVC, FEV 25, FEV 50 and DLCO showed no statistically significant reduction in both treatment groups in 3 and 6 months following completion of RT, compared to baseline. Multivariate analysis showed no relation between HRCT findings and other variables (age, smoking, chemotherapy, hormonotherapy, V20).
Lung toxicity, as assessed with HRCT and PFTs, was minimal in both treatment arms and our results are in consistency with other published data. Hypofractionated RT was a safe modality and well tolerated by the majority of the patients. Longer follow-up is required for robust assessment of incidence of late lung fibrosis in our series.
乳腺癌的大分割放疗方案虽然能为患者和医疗系统降低成本和缩短时间，但可能会对肺部正常组织产生负面影响。我们研究并比较了早期乳腺癌患者在接受三维适形全乳放疗（WBRT）时，采用常规或大分割放疗方案后，肺功能以及放疗后使用高分辨率计算机断层扫描（HRCT）的影像学变化。
2008年至2009年期间，61例早期乳腺癌患者（T1 - 2N0M0）被随机分为两组。A组（n = 31）接受标准放疗，50Gy/25次/5周，瘤床追加10Gy/5次/1周。B组（n = 30）接受43.2Gy/16次/22天，瘤床追加10Gy/5次/1周。两组患者在放疗前第0天（D0）、放疗期间以及放疗结束后3个月和6个月时，均进行动态肺功能测试，包括肺量计检查和气体扩散试验。所有患者在基线时以及放疗结束后3个月、6个月、12个月进行HRCT扫描。放疗结束后3个月和6个月记录呼吸道症状。计算所有患者的剂量学因素，如中央肺剂量（CLD）、接受超过20Gy的肺体积（V20）、D25和平均肺剂量（MLD）。
放疗后3个月，HRCT显示肺部变化分级如下：0级占91.8%，1级占8.19%，2级占0%。6个月时，0级占86.98%，1级占11.47%，2级占1.6%。12个月时，0级占88.52%，1级占9.19%，2级占3.27%。单因素分析显示放射性肺炎、年龄与所有剂量学参数之间存在强关联。分割类型与放射性肺炎的发生率无关联。与基线相比，放疗结束后3个月和6个月时，两组患者的第一秒用力呼气容积（FEV1）、用力肺活量（FVC）、25%用力呼气容积（FEV25）、50%用力呼气容积（FEV50）和一氧化碳弥散量（DLCO）均无统计学意义上的降低。多因素分析显示HRCT结果与其他变量（年龄、吸烟、化疗、激素治疗、V20）之间无关联。
通过HRCT和肺功能测试评估，两个治疗组的肺部毒性均最小，我们的结果与其他已发表数据一致。大分割放疗是一种安全的方式，大多数患者耐受性良好。为了对我们系列中晚期肺纤维化的发生率进行可靠评估，需要更长时间的随访。
