Okumus Dilruba, Sarihan Sureyya, Gozcu Sema, Sigirli Deniz
Department of Radiation Oncology, Faculty of Medicine, Trakya University, Edirne, Turkey.
Department of Radiation Oncology, Faculty of Medicine, Uludag University, 16059 Bursa, Turkey.
Med Dosim. 2017;42(3):169-176. doi: 10.1016/j.meddos.2017.02.002. Epub 2017 May 12.
The patients with non-small cell lung cancer (NSCLC) treated with definitive conformal radiotherapy (RT) were evaluated in terms of side effects and survival. Normal tissue complication probability (NTCP) was calculated for 68 patients treated between 2009 and 2012. Clinical and dosimetric factors were analyzed. The median dose of 63 Gy (range: 54 to 70 Gy) was given with conformal RT with blocks (n = 37), 3-dimensional conformal RT (3DCRT) (n = 11), or intensity-modulated RT (IMRT) (n = 20). Acute grade 1 to 2 radiation pneumonitis (RP) was seen in 13% of the patients. No significant relationship was found between RP and treatment and dosimetric factors (p > 0.05). There was a positive correlation between median "mean lung dose" (MLD) (17 Gy), lung V30 (20.5%), and NTCP (14%) (p < 0.001). Median and 2-year overall survival (OS) and progression-free survival (PFS) were 27 and 18 months and 51% and 42%, respectively. In univariate analysis, significant dose range for survival was found between 59.4 and 63 Gy (p < 0.01). In multivariate analysis, response (p = 0.001), fraction dose of 1.8 Gy (p = 0.002), MLD <18 Gy (p = 0.04) for OS and response (p < 0.001), total dose > 59.4 Gy (p = 0.01), and tumor biologically effective dose (BED)3 ≤ 100.8 (p = 0.01) for PFS were found to be favorable factors. In our study, we found a linear correlation between NTCP and MLD for RP risk estimation in patients with NSCLC. Therapeutic dose range where MLD can be kept under 20 Gy with significant survival benefit was found between 59.4 and 63 Gy. Increased therapeutic efficacy will be possible using risk-adaptive RT techniques.
对接受根治性适形放疗（RT）的非小细胞肺癌（NSCLC）患者的副作用和生存率进行了评估。计算了2009年至2012年期间接受治疗的68例患者的正常组织并发症概率（NTCP）。分析了临床和剂量学因素。采用带挡块的适形放疗（n = 37）、三维适形放疗（3DCRT）（n = 11）或调强放疗（IMRT）（n = 20）给予的中位剂量为63 Gy（范围：54至70 Gy）。13%的患者出现1至2级急性放射性肺炎（RP）。未发现RP与治疗及剂量学因素之间存在显著相关性（p > 0.05）。中位“平均肺剂量”（MLD）（17 Gy）、肺V30（20.5%）与NTCP（14%）之间存在正相关（p < 0.001）。中位和2年总生存期（OS）及无进展生存期（PFS）分别为27个月和18个月，以及51%和42%。单因素分析发现，生存的显著剂量范围在59.4至63 Gy之间（p < 0.01）。多因素分析发现，对于OS，反应（p = 0.001）、1.8 Gy的分次剂量（p = 0.002）、MLD < 18 Gy（p = 0.04），对于PFS，反应（p < 0.001）、总剂量> 59.4 Gy（p = 0.01）以及肿瘤生物学有效剂量（BED）3≤100.8（p = 0.01）是有利因素。在我们的研究中，我们发现NSCLC患者中NTCP与MLD之间存在线性相关性，用于RP风险评估。发现在59.4至63 Gy之间，MLD可保持在20 Gy以下且具有显著生存获益的治疗剂量范围。使用风险适应性放疗技术将有可能提高治疗效果。
