肺低剂量区体积预测急性放射性肺炎价值探讨

目的 观察胸部肿瘤三维适形放疗患者放射性肺炎发生情况,分析其与各临床、剂量学因素关系,探讨低剂量区体积对放射性肺炎的预测价值.方法 2005-2008年本科收治的中晚期非小细胞肺癌(NSCLC)及食管癌患者共161例接受了三维适形放疗,其中局部晚期NSCLC患者53例,处方剂量60 Gy分30～34次,均行长春瑞滨+顺铂同期化疗;食管癌患者108例,处方剂量58～70 Gy分29～35次,单纯放疗46例,余62例接受亚叶酸钙+氟尿嘧啶+顺铂同期化疗.对急性放射性肺炎进行Spearman等级相关分析、Logistic因素分析及受试者工作特征(ROC)曲线分析.结果 随访率100%.全组急性放射性肺炎总发生率为57.8%(93例),其中NSCLC组为94%(50例,4、5级各1例),食管癌组为39.8%(43例,无≥4级病例).等级相关分析结果显示患者性别(r=0.19,P=0.016)、大体肿瘤体积(r=0.52,P=0.000))、平均肺剂量(r=0.33,P=0.000)、肺正常组织并发症概率(r=0.30,P=0.000)、接受5、10、15、20、25、30 Gy照射的肺体积百分比(肺V5～V30,r=0.21～0.29,P=0.000～0.027)均与放射性肺炎发生相关.Logistic因素分析结果显示肺V5(X2=7.07,P=0.008)、大体肿瘤体积(X2=10.21,P=0.001)是预测≥2级放射性肺炎最有价值指标.ROC曲线分析结果显示曲线下面积为0.684,P=0.000;曲线界值为V5=55%.肺V5≥55%组与<55%组≥2级放射性肺炎发生率分别为43%(36/84)和18%(14/77).结论 平均肺剂量、正常组织并发症概率、V5～V30可较好预测放射性肺炎的发生,其中V5可能是最有价值的预测性指标.当V5>55%时≥2级的急性放射性肺炎的发生率可能会明显增加,制定治疗计划时除平均肺剂量、V20、V30外,还应将低剂量区体积限制在适当范围内.     

Radiation pneumonitis following concurrent accelerated hyperfractionated radiotherapy and chemotherapy for limited-stage small-cell lung cancer: Dose-volume histogram analysis and comparison with conventional chemoradiation

PURPOSE: The aim of this study was twofold: to determine whether the dose-volume metrics are valuable in predicting radiation pneumonitis (RP) in small-cell lung cancer (SCLC) patients treated with accelerated hyperfractionated radiotherapy and chemotherapy (AHFRT + CT); and to clarify how AHFRT influences the risk of RP in comparison to conventional once-daily radiotherapy and chemotherapy (QDRT + CT). METHODS AND MATERIALS: Study subjects were 43 patients with SCLC treated with AHFRT + CT. Radiotherapy was delivered at 1.5 Gy/fraction (fr) twice daily to 45 Gy/30 fr/3 weeks. We analyzed the relation between RP incidence and several dosimetric factors. We also compared this series data with our previously published data from lung cancer patients treated with QDRT + CT. RESULTS: Radiation pneumonitis Grades 1, 2, and 3 were observed in 28 patients, 7 patients, and 1 patient, respectively. Univariate analysis revealed that the percentage of lung volume receiving more than 15 Gy, 20 Gy, and 30 Gy (V15, V20, V30) and normal tissue complication probability were of predictive value for the development of RP. The 12-month cumulative incidences of RP greater than Grade 2 were 0%, 7.1%, 25%, and 42.9% in patients with a V20 of < or =20%, 21-25%, 26-30%, and > or =31%, respectively. These incidences were lower than that of our patients treated with QDRT + CT. CONCLUSIONS: Dosimetric factors are valuable in predicting RP in SCLC patients treated with AHFRT + CT. Regarding the incidence of RP, AHFRT appears to have some advantage over QDRT.     

Clinical dose-volume histogram analysis in predicting radiation pneumonitis in Hodgkin's lymphoma

PURPOSE: To quantify the incidence of radiation pneumonitis (RP) in a modern Hodgkin's lymphoma (HL) cohort, and to identify any clinically relevant parameters that may influence the risk of RP. METHODS AND MATERIALS: Between January 2003 and February 2005, 64 consecutive HL patients aged 18 years or older receiving radical mediastinal radiation therapy (RT) were retrospectively reviewed. Symptomatic cases of radiation pneumonitis were identified. Dose-volume histogram parameters, including V(13), V(20), V(30), and mean lung dose (MLD), were quantified. RESULTS: At a median follow-up of 2.1 years, the actuarial survival for all patients was 91% at 3 years. There were 2 (2/64) cases of Radiation Therapy Oncology Group (RTOG) Grade 2 RP (incidence 3.1%). Both index cases with corresponding V(20) values of 47.0% and 40.7% were located in the upper quartile (2/16 cases), defined by a V(20) value of > or =36%, an incidence of 12.5% (p = 0.03). Similarly for total MLD, both index cases with values of 17.6 Gy and 16.4 Gy, respectively, were located in the upper quartile defined by MLD > or =14.2 Gy, an incidence of 11.8% (2/17 cases, p = 0.02). CONCLUSIONS: Despite relatively high V(20) values in this study of HL patients, the incidence of RP was only 3%, lower compared with the lung cancer literature. We suggest the following clinically relevant parameters be considered in treatment plan assessment: a V(20) greater than 36% and an MLD greater than 14 Gy, over and above which the risk of RTOG Grade 2 or greater RP would be considered clinically significant.     

Postoperative pulmonary complications after preoperative chemoradiation for esophageal carcinoma: correlation with pulmonary dose-volume histogram parameters

PURPOSE: To clarify the relationship between the percentage of lung receiving low radiation doses with concurrent chemotherapy and the occurrence of postoperative pulmonary complications in the treatment of esophageal carcinoma. METHODS: From 117 patients who underwent preoperative chemoradiation for esophageal cancer at our institution between 1998 and 2002, we selected 61 patients for whom complete pulmonary dose-volume histogram (DVH) data were available and analyzed the incidence of pneumonia and acute respiratory distress syndrome (ARDS) in this group. All patients received concurrent chemoradiation therapy, and 39 patients also received induction chemotherapy before concurrent chemoradiation. The median age was 62 years, and the median radiotherapy dose was 45 Gy. The percentage of lung volume receiving at least 10 Gy (V10), 15 Gy (V15), and 20 Gy (V20) were recorded from each pulmonary DVH. RESULTS: Eleven (18%) of the 61 patients had pulmonary complications, 2 of whom died after progression of pneumonia. Pulmonary complications were noted more often (35% vs. 8%, p = 0.014) when the pulmonary V10 was > or =40% vs. <40% and when the V15 was > or /=30% vs. < 30% (33% vs. 10%, p = 0.036). An apparent increase in pulmonary complication rate when V20 was > or =20% vs. <20% (32% vs. 10%, p = 0.079) was not significant. None of the other factors analyzed (surgical procedure, tumor location, use of induction chemotherapy, use of concurrent taxane-based chemoradiation, or smoking history) was associated with the occurrence of pulmonary complications. The median hospital stay was 17 days for patients who had pulmonary complications vs. 12 days for patients who did not (p = 0.08). CONCLUSIONS: The use of multimodality therapy may require minimization of lung volume irradiation to levels lower than previously expected. Radiotherapy techniques that decrease the volume of lung receiving low radiation doses may significantly reduce the risk of this potentially life-threatening complication.     

肺癌与食管癌螺旋断层放疗致放射性肺炎的临床观察

目的 探讨螺旋断层放疗（HT）治疗肺癌与食管癌致放射性肺炎的发生情况及与双肺剂量体积（DVH）和临床病理特征的关系。方法 回顾性分析HT 治疗的19例肺癌和14食管癌患者的临床资料。全组患者中13例仅行HT治疗,20例联合化疗。放疗剂量：小细胞肺癌54～61.8Gy／27～28次,非小细胞肺癌54～66Gy／25～31次,食管癌60～66Gy／28～30次。结果 全组33例患者中,发生0级放射性肺炎8例（24.2％）,1级15例（45.4％）,2级1例（3.0％）,3级5例（15.2％）,5级4例（12.1％）。DVH参数分析显示,发生≥2级放射性肺炎与V30～V45有关,与V5～V25、双肺平均剂量（MLD）、计划靶区（PTV）无关。临床病理特征中,发生≥2级放射性肺炎与ECOG评分有关,与病种、性别、年龄、吸烟、慢性阻塞性肺病和化疗情况无关。结论 HT治疗肺癌与食管癌未明显增加放射性肺炎的发生率,一般状态差、分期晚的患者应严格限制DVH。     

Analysis of dose-volume histogram parameters for radiation pneumonitis after definitive concurrent chemoradiotherapy for esophageal cancer

Purpose

To evaluate dose-volume histogram (DVH) parameters as predictors of radiation pneumonitis (RP) in esophageal cancer patients treated with definitive concurrent chemoradiotherapy.

Patients and methods

Thirty-seven esophageal cancer patients treated with radiotherapy with concomitant chemotherapy consisting of 5-fluorouracil and cisplatin were reviewed. Radiotherapy was delivered at 2 Gy per fraction to a total of 60 Gy. For most of the patients, two weeks of interruption was scheduled after 30 Gy. The percentage of lung volume receiving more than 5-50 Gy in increments of 5 Gy (V5-V50, respectively), and the mean lung dose (MLD) were analyzed.

Results

Ten (27%) patients developed RP of grade 2; 2 (5%), grade 3; 0 (0%), grade 4; and 1 (3%), grade 5. By univariate analysis, all DVH parameters (i.e., V5-V50 and MLD) were significantly associated with grade ?2 RP (p < 0.01). The incidences of grade ?2 RP were 13%, 33%, and 78% in patients with V20s of ?24%, 25-36%, and ?37%, respectively. The optimal V20 threshold to predict symptomatic RP was 30.5% according to the receiver operating characteristics curve analysis.

Conclusion

DVH parameters were predictors of symptomatic RP and should be considered in the evaluation of treatment planning for esophageal cancer.     

肺癌同期放化治疗中放射性肺损伤的相关因素分析

 目的 观察三维适形放疗联合同期化疗治疗局部晚期非小细胞肺癌中放射性肺损伤情况,对其相关因 素进行分析,寻找合理的预测性 指标。 方法 47例符合入组条件的非小细胞肺癌患者接受三维适形放疗及同期化疗。处方剂量为60Gy常规 放疗,同期化疗方案为NP方案,对三维适形治疗计划及临床资料进行单因素、多因素分析,评 价肺损伤情况。 结果 （1）完全缓解3例, 部分缓解42例,总有效率为95.74%,1年生存率75.78%。全组发生急性放 射性肺炎0级2例,1级20 例,2级17例,3级8例,无4级放射性肺炎发生。（2）与严重放射性肺炎发生呈正相关的剂量 学因素为MLD、肺NTCP,肺V5、 V15、V20。临床资料中仅发现肿瘤GTV与严重放射性肺炎发生相关;多因素分析显示全肺平均 剂量为放射性肺炎的独立影 响因素。 结论 剂量学因素（MLD、肺NTCP,肺V5、V15、V20）可以较好地预测严重放射性肺炎的发生,全肺 平均剂量是放射性肺炎发生的独立影响因素。     

Dose-volumetric parameters of acute esophageal toxicity in patients with lung cancer treated with three-dimensional conformal radiotherapy

PURPOSE: To retrospectively evaluate which dose-volumetric parameters are associated with the risk of > or = Grade 3 acute esophageal toxicity (AET) in lung cancer patients treated with three-dimensional conformal radiotherapy (3D-CRT). METHODS AND MATERIALS: One hundred twenty-four lung cancer patients treated curatively with 3D-CRT were retrospectively analyzed. All patients received conventionally fractionated radiotherapy (RT) with median dose of 60 Gy (range, 54-66 Gy) delivered in 30 fractions (range, 27-33 fractions). Thirty-one patients underwent curative surgery before RT. Ninety-two patients received chemotherapy (induction, 18; concurrent +/- induction, 74). Acute esophageal toxicity was scored by Radiation Therapy Oncology Group criteria. The parameters analyzed included sex; age; Karnofsky performance score; weight loss; surgery; concurrent chemotherapy; the percentages of organ volume receiving > or =20 Gy (V20), > or =30 Gy (V30), > or =40 Gy (V40), > or =50 Gy (V50), > or =55 Gy (V55), > or = 58 Gy (V58), > or =60 Gy (V60), and > or =63 Gy (V63); the percent and absolute length of the esophagus irradiated; the maximum and mean dose to the esophagus; and normal tissue complication probability. RESULTS: Of the 124 patients, 15 patients (12.1%) had Grade 3 AET, and 1 (0.8%) patient had Grade 4 AET. There was no fatal Grade 5 AET. In univariate and multivariate logistic regression analyses, concurrent chemotherapy and V60 were significantly associated with the development of severe (> or = Grade 3) AET (p < 0.05). Severe AET was observed in 15 of 74 patients (20.3%) who received concurrent chemotherapy, and in 1 of 50 patients (2.0%) who did not (p = 0.002). Severe AET was observed in 5 of 87 patients (5.7%) with V60 < or = 30% and in 11 of 37 patients (29.7%) with V60 > 30% (p < 0.001). Among 50 patients who did not receive concurrent chemotherapy, severe AET was observed in 0 of 43 patients (0%) with V60 < or = 30% and in 1 of 7 patients (14.2%) with V60 > 30% (p = 0.140). Among 74 patients who received concurrent chemotherapy, severe AET was observed in 5 of 44 patients (11.4%) with V60 < or = 30% and in 10 of 30 patients (33.3%) with V60 > 30% (p = 0.037). CONCLUSIONS: Concurrent chemotherapy and V60 were associated with the development of severe AET > or = Grade 3. For patients being treated with concurrent chemotherapy, V60 is considered to be a useful parameter predicting the risk of severe AET after conventionally fractionated 3D-CRT for lung cancer.     

非小细胞肺癌三维适形放疗同期化疗后急性放射性肺炎发生因素分析

目的 分析三维适形放疗同期化疗非小细胞肺癌急性放射性肺炎(RP)的发生率及相关因素.方法 搜集2006年1月到2008年10月间首程行三维适形放疗并同期化疗的非小细胞肺癌病例90例,对相关放射剂量体积资料和治疗毒性的临床资料进行统计分析.结果 1级急性RP的发生率为32.2%,2级30.0%,3级5.6%,4级0%,5级1.1%.临床因素单因素分析有统计学差异的是原发肿瘤部位.剂量学方面当平均肺剂量以17 Gy,V_5、V_(10)、V_(20)、V_(30)、V_(40)分别以47%、36%、24%、23%、22%为界分组时组间差异有统计学意义.多因素分析显示平均肺剂量是独立预测因子.结论 RP的发生发展受到多因素综合作用,制定肺癌尤其是中下叶肺癌的三维放疗计划时应将平均肺剂量控制在17 Gy以下.     

Subjective Global Assessment (SGA) Score Could Be a Predictive Factor for Radiation Pneumonitis in Lung Cancer Patients With Normal Pulmonary Function Treated by Intensity-Modulated Radiation Therapy and Concurrent Chemotherapy

Introduction

To investigate the relationship between malnutrition and the severity of radiation pneumonitis (RP) in patients with lung cancer with normal baseline pulmonary function and lungs' V20 < 35% treated by intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy.

Evaluation of the Radiation Pneumonia Development Risk in Lung Cancer Cases

Background: Concurrent chemo-radiotherapy is the recommended standard treatment modality for patients with locally advanced lung cancer. The purpose of three-dimensional conformal radiotherapy (3DCRT) is to minimize normal tissue damage while a high dose can be delivered to the tumor. The most common dose limiting side effect of thoracic RT is radiation pneumonia (RP). In this study we evaluated the relationship between dose-volume histogram parameters and radiation pneumonitis. This study targeted prediction of the possible development of RP and evaluation of the relationship between dose-volume histogram (DVH) parameters and RP in patients undergoing 3DCRT. Materials and Methods: DVHs of 41 lung cancer patients treated with 3DCRT were evaluated with respect to the development of grade ≥ 2 RP by excluding gross tumor volume (GTV) and planned target volume (PTV) from total (TL) and ipsilateral (IPSI) lung volume. Results: Were admitted statistically significant for p<0.05. Conclusions: The cut-off values for V5, V13, V20, V30, V45 and the mean dose of TL-GTV; and V13, V20,V30 and the mean dose of TL-PTV were statistically significant for the development of Grade ≥2 RP. No statistically significant results related to the development of Grade ≥2 RP were observed for the ipsilateral lung and the evaluation of PTV volume. A controlled and careful evaluation of the dose-volumehistograms is important to assess Grade ≥2 RP development of the lung cancer patients treated with concurrent chemo-radiotherapy. In the light of the obtained data it can be said that RP development may be avoided by the proper analysis of the dose volume histograms and the application of optimal treatment plans.     

Phase II trial of paclitaxel, carboplatin, and concurrent radiation therapy for locally advanced non-small-cell lung cancer

We conducted a phase II trial to investigate the efficacy of concurrent chemoradiation in patients with stage III non-small-cell lung cancer (NSCLC). Thirty patients with inoperable NSCLC were enrolled onto a multicenter phase II trial of concurrent chemoradiation therapy. Patients received six weekly cycles of paclitaxel 45 mg/m(2) over 1 h; carboplatin at (area under the curve) AUC 2; and radiation therapy of 60 Gy. Radiation was administered to the primary tumor and regional lymph nodes (40 Gy over 4 weeks) followed by a boost to the primary tumor (20 Gy in 2 weeks). After the initial phase of concurrent chemoradiation, patients received an additional four cycles of paclitaxel 175 mg/m(2) over 3 h and carboplatin at AUC 6 every 3 weeks. The overall objective response rate of 30 assessable patients was 76.7%. At the median follow-up time of 13.1 months, the median survival time was 14.5 months (95% CI, 10.59-18.48). The median progression-free survival was 10.5 months (95% CI, 7.72-13.28). The major toxicity was hematologic. The incidence of grade 3 esophagitis was 10%. In conclusion, this chemoradiation regimen is well tolerated and shows significant clinical results for locally advanced NSCLC. Locoregional failure rate remains an important issue with this newer chemotherapeutic regimen. A novel chemotherapy and radiation therapy is clearly needed.     

欧美和亚裔人群放射性肺炎发生率Meta分析

目的 比较欧美和亚裔人群肺癌患者放射性肺炎(RP)发生率的差异。方法 计算机检索PubMed、Embase、Cochrane library数据库,检索与肺癌和RP相关研究,根据研究开展所在地不同将检出研究分为亚洲地区与欧美澳地区研究两类,分别汇总RP发生率数据;在PubMed数据库检索与剂量学参数相关的研究。结果 14项研究共 3190例患者纳入分析,Meta分析结果显示亚洲地区和欧美澳地区患者≥3级RP发生率相近(4.9%∶4.6%,P=0.895),而5级RP发生率亚洲地区患者显著高于欧美澳地区患者(1.5%∶0.2%,P=0.002),且亚洲组研究中患者肺受量较低。21项研究报道了 肺V20Gy剂量限定标准,进一步分析发现两地区研究间 肺V20Gy剂量限定标准未达到统计学差异(P=0.440),亚洲地区研究的肺受量限定可能更为严格。结论 亚洲地区肺癌患者较欧美澳地区患者在放化疗后发生RP概率较高;将单纯基于国外患者研究数据制定的胸部放疗方案应用于亚洲地区患者时,要注意剂量限定标准的差异。     

Dose–volume factors predicting radiation pneumonitis in patients receiving salvage radiotherapy for postlobectomy locoregional recurrent non-small-cell lung cancer

Background The correlation between treatment-related factors and lung toxicity has not been sufficiently evaluated in salvage radiotherapy. Methods Twenty-one patients with recurrent non-small- cell lung cancer (NSCLC) after lobectomy received salvage radiotherapy to a total dose of 46–60 Gy. The effects of radiotherapy parameters on the development of radiation pneumonitis (RP) were examined using dose–volume histograms. Results Grade 1 RP was observed in 4, grade 2 in 2, and grade 3 in 1 patient. Patients who developed RP had a significantly higher value in V dose (V13, V20) parameters and mean lung dose (MLD) than those who did not develop RP. Concerning G2 or higher RP, 3 patients who developed ≥G2 RP had a significantly higher value in V20, V13, and MLD than the remaining patients with P values of 0.01, 0.015, and 0.016, respectively. The mean V20, V13, and MLD in these 3 patients were 27%, 29.3%, and 14.8 Gy, respectively, whereas the mean V20, V13, and MLD in the remaining 18 patients were 15.8%, 18.3%, and 8.8 Gy, respectively. Three of 6 patients with a V20 ≥20% developed ≥G2 RP whereas this did not occur in the remaining patients (P = 0.015). Similarly, 3 of 6 patients with a V13 ≥23% developed ≥G2 RP whereas this did not occur in the remaining patients (P = 0.015). Conclusions These data suggest that a somewhat lower V dose value or MLD, as compared with the setting of definitive radiotherapy, could be a surrogate for RP in patients undergoing salvage radiotherapy for recurrent NSCLC.     

非小细胞肺癌术后适形放疗肺损伤相关因素研究

目的 分析非小细胞肺癌(NSCLC)术后接受三维适形放疗(3DCRT)肺损伤的相关因素.方法 对2002年11月至2006年3月符合入组条件的90例患者进行回顾性分析,其中Ⅰ～Ⅱ期12例(切缘阳性),ⅢA期53例,ⅢB期25例.术后均接受了中位剂量60 Gy的3DCRT,38例接受了中位3周期术后化疗.观察指标为CTC 3.0 2级以上放射性肺炎(RP).应用ROC曲线分析健侧、患侧和双肺接受x Gy剂量的相对体积(Vx)和绝对体积与RP的关系.结果 全组共9例患者出现有症状的RP,RP发生率为10%.接受全肺切除的20例患者中无RP发生.RP中位发生时间在放疗开始后101 d,其中2级7例,3级2例.双肺V30、V35在RP组明显高于未发生RP组(19%∶14%,U=-2.16,P=0.030;15%:11%,U=-2.65,P=0.007).以患侧肺接受30 Gy照射的绝对体积作为分界点进行ROC曲线分析结果 显示曲线下面积为0.757,对RP预测的敏感性为88%、特异性为70%.患肺接受30 Gy照射的绝对体积>340 cm3的RP发生率明显高于体积<340 cm3的(29%∶3%,x2=9.75,P=0.003).结论 对于肺叶切除的NSCLC患者接受术后放疗,患肺接受30 Gy照射的绝对体积与RP相关.对全肺切除患者,单肺V20限制在10%以下,接受术后放疗是安全可行的.     

Dose-volume histogram analysis as predictor of radiation pneumonitis in primary lung cancer patients treated with radiotherapy

PURPOSE: To determine the relationship between various parameters derived from lung dose-volume histogram analysis and the risk of symptomatic radiation pneumonitis (RP) in patients undergoing radical radiotherapy for primary lung cancer. METHODS AND MATERIALS: The records of 156 patients with lung cancer who had been treated with radical radiotherapy (>/=45 Gy) and for whom dose-volume histogram data were available were reviewed. The incidence of symptomatic RP was correlated with a variety of parameters derived from the dose-volume histogram data, including the volume of lung receiving 10 Gy (V(10)) through 50 Gy (V(50)) and the mean lung dose (MLD). RESULTS: The rate of RP at 6 months was 15% (95% confidence interval 9-22%). On univariate analysis, only V(30) (p = 0.036) and MLD (p = 0.043) were statistically significantly related to RP. V(30) correlated highly positively with MLD (r = 0.96, p < 0.001). CONCLUSION: V(30) and MLD can be used to predict the risk of RP in lung cancer patients undergoing radical radiotherapy.     

A prospective study on radiation pneumonitis following conformal radiation therapy in non-small-cell lung cancer: clinical and dosimetric factors analysis.

BACKGROUND AND PURPOSE: Clinical and dosimetric prognostic factors for radiation pneumonitis (RP) have been reported after three-dimensional conformal radiotherapy (3D-CRT) in patients with non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Ninety-six patients who received 3D-CRT for stage IA to IIIB NSCLC were evaluated prospectively. Surgery was performed before radiation in 51% of the patients (n = 49). RP was diagnosed six-eight weeks after 3D-CRT using the Lent-Soma classification. Factors evaluated included treatment factors such as total mean lung dose (MLD), and dose-volume histogram (DVH) thresholds for several radiation dose steps. These thresholds were originally determined from the median of the irradiated lung volume at each step. RESULTS: Six patients could not be evaluated for RP six weeks after 3D-CRT. Of the 90 remaining patients, 40 (44%) had RP (i.e. grade > or =1) at 6 weeks, including 7 patients (7.8%) with severe RP (grade > or =2). Regarding the whole toxicity (grade > or =1), age (> or =60 years), MLD, V20 and V30 were significantly related to RP. DVH thresholds determined for radiation doses from 20 to 40 Gy were also predictive of RP. Considering only severe RP (grade > or =2), only MLD, V20 and V30 remained associated with increased acute pulmonary toxicity. CONCLUSIONS: In this study, dosimetric factors (MLD, V20, V30) and age (> or =60 years) were predictive of RP regarding the whole pulmonary toxicity (grade > or =1). In addition, thresholds from 20 to 40 Gy, based on a stratification according to the median of the percentage of irradiated lung volume, were also predictive factors. They may, therefore, help discriminate patients at high and low risk for RP. However, only MLD, V20 and V30 remained associated with severe RP (grade > or =2), probably due to the small number of severe events in our series.     

Incidence and Risk Factors of Symptomatic Radiation Pneumonitis in Non–Small-Cell Lung Cancer Patients Treated with Concurrent Chemoradiotherapy and Consolidation Durvalumab

IntroductionData on the risk factors for symptomatic radiation pneumonitis (RP) in non–small-cell lung cancer (NSCLC) patients treated with concurrent chemoradiotherapy (CCRT) and consolidation durvalumab are limited; we aimed to investigate these risk factors.Materials and MethodsThis multicenter retrospective study, conducted at 15 institutions in Japan, included patients who were ≥20 years of age; who started definitive CCRT for NSCLC between July 1, 2018, and July 31, 2019; and who then received durvalumab. The primary endpoint was grade 2 or worse (grade 2+) RP.ResultsIn the 146 patients analyzed, the median follow-up period was 16 months. A majority of the patients had stage III disease (86%), received radiation doses of 60 to 66 Gy equivalent in 2-Gy fractions (93%) and carboplatin and paclitaxel/nab-paclitaxel (77%), and underwent elective nodal irradiation (71%) and 3-dimensional conformal radiotherapy (75%). RP grade 2 was observed in 44 patients (30%); grade 3, in four patients (3%); grade 4, in one patient (1%); and grade 5, in one patient (1%). In the multivariable analysis, lung V20 was a significant risk factor, whereas age, sex, smoking history, irradiation technique, and chemotherapy regimen were not. The 12-month grade 2+ RP incidence was 34.4% (95% confidence interval [CI], 26.7%-42.1%); the values were 50.0% (95% CI, 34.7%-63.5%) and 27.1% (95% CI, 18.8%-36.2%) in those with lung V20 ≥ 26% and < 26%, respectively (P = .007).ConclusionThe incidence of grade 2+ RP was relatively high in this multicenter real-world study, and its risk increased remarkably at elevated lung V20. Our findings can aid in RP risk prediction and the safe radiotherapy treatment planning.