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.     

3DCRT计划中不同肺定义对肺癌放疗的影响

目的 探讨3DCRT计划中双肺－GTV、CTV、PTV三种定义下正常肺DVH参数差异及对RP的预测价值。方法 对2006—2010年间行3DCRT的147例NSCLC患者分别定义双肺－GTV、CTV、PTV正常肺并收集相关DVH剂量学信息,比较参数值差异及其对RP的预测价值。剂量学参数间差异采用成组t检验,用ROC曲线分析各剂量学因素的预测价值。结果 以MLD为例,双肺－GTV定义下与双肺－CTV、PTV的差值分别为(1.16±0.96)、(3.45±1.43) Gy。同一患者不同定义下MLD最大差值为8.73 Gy。双肺－GTV下MLD对≥2、3级RP预测价值优于双肺－CTV、PTV的,表现为ROC曲线下面积较大,分别为0.614和0.678、0.566和0.602、0.551和0.616(P=0.024和0.056、0.269和0.226、0.317和0.167)。对肺V₅—V₅₀的分析也得出类似结论。结论 基于不同定义下所得的剂量学参数存在较大差异,临床不能忽视;基于双肺－GTV所得相关剂量学参数对RP预测价值最佳,建议采用。     

非小细胞肺癌三维适形放疗剂量体积直方图参数与放射性肺损伤CT分级的关系

目的 探讨剂量体积直方图(DVH)参数与非小细胞肺癌(NSCLC)三维适形放疗(3D-CRT)后放射性肺损伤CT分级的关系.方法 将3D-CRT治疗后CT随访6个月以上的169例Ⅰ～Ⅲ期NSCLC患者,按随访CT放射性肺损伤的表现分级(0～4级),并分为CT阳性组(2～4级)和CT阴性组(0～1级).从放疗计划中获取患者的DVH参数,分析DVH参数与放射性肺损伤CT分级的关系,评价DVH参数对放射性肺损伤的预测价值.结果 不同CT分级的全肺及患侧肺正常组织并发症概率(NTCP)值差异有统计学意义,随着CT分级的增加,NTCP相应增大.不同CT分级的全肺及患侧肺平均肺受照剂量(MLD)差异有统计学意义,随着CT分级的增加,全肺及患侧肺MLD相应增大.不同CT分级的全肺及患侧肺V20、V30和V40差异均有统计学意义,随着CT分级的增加,全肺及患侧肺V20、V30、V40相应增大.不同CT分级患者健侧肺的DVH参数差异无统计学意义.全肺、患侧肺DVH参数与患侧肺CT分级联系紧密,其中患侧肺NTCP与CT分级关联度最强(η=0.522).结论 NTCP、MID、V20、V30、V40等DVH参数与NSCLC 3D-CRT后放射性肺损伤的CT分级密切相关,可以作为评价及优化放疗计划的指标,以减少放疗后放射性肺损伤的发生.     

肺癌、纵隔肿瘤及食管癌放疗后放射性肺炎发生因素的对比研究

 目的　对肺癌（肺靶区）与纵隔肿瘤及食管癌（纵隔靶区）三维适形放疗中放射性肺炎（RP）发生的影响因素及剂量体积直方图（DVH）参数进行对比研究。方法　回顾性分析接受放射治疗的肺癌、纵隔肿瘤及食管癌患者83例的临床资料,采用χ2 检验对临床因素（性别、年龄、肿瘤部位、分期、化疗）与RP发生的相关性进行分析;分别对两靶区的DVH参数与RP的发生进行相关性分析;用t检验对肺靶区与纵隔靶区DVH参数进行比较。结果　≥2级 RP 发生率为36.5 %（31／81）。各临床因素与≥2级RP发生无关（χ2 值分别为0.377、0.215、0.018、0.717、0.215,均P＞0.05）。两靶区的DVH参数中,V5、V10、V20、V30、全肺平均剂量（MLD）与RP的发生均具有明显相关性。两靶区发生RP的患者V5[（50.9±17.8）%、（69.9±20.4）%]（t＝2.745,P＜0.05）、V10[（38.6±15.2）%、（53.5±18.8）%]（t＝2.434,P＜0.05）差异均有统计学意义,而V20（t＝0.388,P＞0.05）、V30（t＝0.005,P＞0.05）及MLD（t＝0.138,P＞0.05）差异均无统计学意义。两靶区未发生RP患者的DVH参数t检验后得到类似结果。结论　在肺靶区、纵隔靶区的放疗中,RP的发生与DVH参数密切相关,尤其是V20、V30及MLD对RP的发生有重要的影响。     

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-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.     

Radiation Pneumonitis in Breast Cancer Patients Who Received Radiotherapy Using the Partially Wide Tangent Technique after Breast Conserving Surgery

Purpose

We assessed the risk of radiation pneumonitis (RP) in terms of dosimetric parameters in breast cancer patients, who received radiotherapy using the partially wide tangent technique (PWT), following breast conservation surgery (BCS).

Methods

We analyzed the data from 100 breast cancer patients who underwent radiotherapy using PWT. The entire breast, supraclavicular lymph node, and internal mammary lymph node (IMN) were irradiated with 50.4 Gy in 28 fractions. RP was scored on a scale of 0 to 5, based on Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity criteria. The dosimetric parameters, used in analysis for the ipsilateral lung, were the mean lung dose (MLD), V₅ (percentage of lung volume that received a dose of 5 Gy or more)-V₅₀, and normal tissue complication probability (NTCP).

Results

Of the 100 patients, three suffered from symptomatic RP (symptom grade ≥2), but were relieved by supportive care. The risk of RP was not correlated with the treatment regimen. RP associated mostly with asymptomatic minimal pulmonary radiologic change or mild dry cough developed more frequently in the group with MLD ≥20.5 Gy or NTCP ≥23% than in the group with MLD <20.5 Gy and NTCP <23% (48.6% vs. 25.4%, p=0.018).

Conclusion

Dosimetric parameters of MLD and NTCP were correlated with the incidence of RP, but the clinical impact was minimal. We suggest that PWT is a safe technique for the treatment of IMN for BCS patients with low risk of symptomatic RP.     

Factors predicting radiation pneumonitis in lung cancer patients: a retrospective study.

PURPOSE: To evaluate clinical and lung dose-volume histogram based factors as predictors of radiation pneumonitis (RP) in lung cancer patients (PTs) treated with thoracic irradiation. METHODS AND MATERIALS: Records of all lung cancer PTs irradiated at our Institution between 1994 and 2000 were retrospectively reviewed. Eighty-four PTs with small or non-small-cell lung cancer, irradiated at >40 Gy, with full 3D dosimetry data and a follow-up time of >6 months from start of treatment, were analysed for RP. Pneumonitis was scored on the basis of SWOG toxicity criteria and was considered a complication when grade> or =II. The following clinical parameters were considered: gender, age, surgery, chemotherapy agents, presence of chronic obstructive pulmonary disease (COPD), performance status. Dosimetric factors including prescribed dose (Diso), presence of final conformal boost, mean lung dose (Dmean), % of lung receiving > or =20, 25, 30, 35, 40, and 45 Gy (respectively V20-->V45), and normal tissue complication probability (NTCP) values were analysed. DVHs data and NTCP values were collected for both lungs considered as a paired organ. Median and quartile values were taken as cut-off for statistical analysis. Factors that influenced RP were assessed by univariate (log-rank) and multivariate analyses (Cox hazard model). RESULTS: There were 14 PTs (16.6%) who had > or =grade II pulmonary toxicity. In the entire population, the univariate analysis revealed that many dosimetric parameters (Diso, V20, V30, V40, V45) were significantly associated with RP. No significant correlation was found between the incidence of RP and Dmean or NTCP values. Multivariate analysis revealed that the use of mitomycin (MMC) (P=0.005) and the presence of COPD (P=0.026) were the most important risk factor for RP. In the group without COPD (55 PTs, seven RP) a few dosimetric factors (Dmean, V20, V45) and NTCP values (all models) were associated with RP in the univariate analysis (P< or =0.06). According to the multivariate analysis, the use of MMC was independently associated with RP (P=0.007), while Dmean approached statistical significance (P=0.082). CONCLUSIONS: In this study the use of mitomycin or the presence of COPD is associated with a higher risk of RP. In the entire population NTCP values were not significantly correlated with the incidence of RP. Mean lung dose shows a clear trend toward statistical significance in the patient group without COPD.     

Regional differences in lung radiosensitivity after radiotherapy for non-small-cell lung cancer

PURPOSE: To study regional differences in lung radiosensitivity by evaluating the incidence of radiation pneumonitis (RP) in relation to regional dose distributions. METHODS AND MATERIALS: Registered chest CT and single photon emission CT lung perfusion scans were obtained in 106 patients before curative or radical radiotherapy for non-small-cell lung cancer. The mean lung dose (MLD) was calculated. The single photon-emission CT perfusion data were used to weigh the MLD with perfusion, resulting in the mean perfusion-weighted lung dose. In addition, the lungs were geometrically divided into different subvolumes. The mean regional dose (MRD) for each region was calculated and weighted with the perfusion of each region to obtain the mean perfusion-weighted regional dose. RP was defined as respiratory symptoms requiring steroids. The incidence of RP for patients with tumors in a specific subvolume was calculated. The normal tissue complication probability (NTCP) parameter values for the TD(50), and an offset NTCP parameter for tumor location were fitted for both lungs and for each lung subvolume to the observed data using maximum likelihood analysis. RESULTS: The incidence of RP correlated significantly with the MLD and MRD of the posterior, caudal, ipsilateral, central, and peripheral lung subvolumes (p between 0.05 and 0.002); no correlation was seen for the anterior, cranial, and contralateral regions Similarly, a statistically significant correlation was observed between the incidence of RP and the perfusion-weighted MLD and perfusion-weighted MRD for all regions, except the anterior lung region. For this region, the dose-effect relation improved remarkably after weighting the local dose with the local perfusion. A statistically significant difference (p = 0.01) in the incidence of RP was found between patients with cranial and caudal tumors (11% and 40%, respectively). Therefore, a dose-independent offset NTCP parameter for caudal tumors was included in the NTCP model, improving most correlations significantly, confirming that patients with caudal tumors have a greater probability of developing RP. CONCLUSION: The incidence of RP correlated significantly with the MLD and MRD of most lung regions, except for the anterior, cranial, and contralateral regions. Weighting the local dose with the local perfusion improved the dose-effect relation for the anterior lung region. Irradiation of caudally located lung tumors resulted in a greater risk of RP than irradiation of tumors located in other parts of the lungs.     

非小细胞肺癌同期放化疗后重度急性放射性肺炎的预测模型研究

目的 利用剂量体积直方图(DVH)参数建立Logistic剂量反应及Lyman-Kutcher-Burman正常组织并发症概率(LKB-NTCP)模型,并评估其对非小细胞肺癌同期放化疗后重度急性放射性肺炎(SARP)的预测价值。方法 搜集2006—2010年间行三维适形放疗同期化疗的147例非小细胞肺癌患者资料。按美国RTOG毒性评价标准定义超过3级的ARP为SARP。根据DVH剂量学信息建立Logistic剂量反应模型和LKB-NTCP模型。结果 SARP 发生率为9.5%(14/147)。Logistic剂量反应模型参数:常数b₀=－6.66、b₁=0.252,TD₅₀=26.43 Gy,γ₅₀=1.67;模型曲线在17 Gy以下相对平坦,17~18 Gy处变为陡峭,SARP风险增大。LKB-NTCP模型参数:体积效应因子n=0.87±0.40,曲线斜率倒数m=0.27±0.10,TD₅₀₍₁₎=(29.5±8.0) Gy;Logistic回归及ROC分析均发现此参数下计算出NTCP值对SARP有良好预测价值(P=0.013、0.019)。结论 NTCP值对SARP的预测价值优于简单剂量参数,2个模型曲线均提示最大限制剂量在约17 Gy。     

Comparing different NTCP models that predict the incidence of radiation pneumonitis. Normal tissue complication probability

PURPOSE: To compare different normal tissue complication probability (NTCP) models to predict the incidence of radiation pneumonitis on the basis of the dose distribution in the lung. METHODS AND MATERIALS: The data from 382 breast cancer, malignant lymphoma, and inoperable non-small-cell lung cancer patients from two centers were studied. Radiation pneumonitis was scored using the Southwestern Oncology Group criteria. Dose-volume histograms of the lungs were calculated from the dose distributions that were corrected for dose per fraction effects. The dose-volume histogram of each patient was reduced to a single parameter using different local dose-effect relationships. Examples of single parameters were the mean lung dose (MLD) and the volume of lung receiving more than a threshold dose (V(Dth)). The parameters for the different NTCP models were fit to patient data using a maximum likelihood analysis. RESULTS: The best fit resulted in a linear local dose-effect relationship, with the MLD as the resulting single parameter. The relationship between the MLD and NTCP could be described with a median toxic dose (TD(50)) of 30.8 Gy and a steepness parameter m of 0.37. The best fit for the relationship between the V(Dth) and the NTCP was obtained with a D(th) of 13 Gy. The MLD model was found to be significantly better than the V(Dth) model (p <0.03). However, for 85% of the studied patients, the difference in NTCP calculated with both models was <10%, because of the high correlation between the two parameters. For dose distributions outside the range of the studied dose-volume histograms, the difference in NTCP, using the two models could be >35%. For arbitrary dose distributions, an estimate of the uncertainty in the NTCP could be determined using the probability distribution of the parameter values of the Lyman-Kutcher-Burman model. CONCLUSION: The maximum likelihood method revealed that the underlying local dose-effect relation for radiation pneumonitis was linear (the MLD model), rather than a step function (the V(Dth) model). Thus, for the studied patient population, the MLD was the most accurate predictor for the incidence of radiation pneumonitis.     

Incidence of radiation pneumonitis after thoracic irradiation: Dose-volume correlates

PURPOSE: To define clinical and dosimetric parameters correlated with the risk of clinically relevant radiation pneumonitis (RP) after thoracic radiotherapy. METHODS AND MATERIALS: Records of consecutive patients treated with definitive thoracic radiotherapy were retrospectively reviewed for the incidence of RP of Grade 2 or greater by the Common Toxicity Criteria. Dose-volume histograms using total lung volume (TL) and TL minus gross tumor volume (TL-G) were created with and without heterogeneity corrections. Mean lung dose (MLD), effective lung volume (V(eff)), and percentage of TL or TL-G receiving greater than or equal to 10, 13, 15, 20, and 30 Gy (V10-V30, respectively) were analyzed by logistic regression. Receiver operating characteristic (ROC) curves were generated to estimate RP predictive values. RESULTS: Twelve cases of RP were identified in 92 eligible patients. Mean lung dose, V10, V13, V15, V20, and V(eff) were significantly correlated to RP. Combinations of MLD, V(eff), V20, and V30 lost significance using TL-G and heterogeneity corrections. Receiver operating characteristic analysis determined V10 and V13 as the best predictors of RP risk, with a decrease in predictive value above those volumes. CONCLUSIONS: Intrathoracic radiotherapy should be planned with caution when using radiotherapy techniques delivering doses of 10 to 15 Gy to large lung volumes.     

Early clinical and radiological pulmonary complications following breast cancer radiation therapy: NTCP fit with four different models.

OBJECTIVE: To fit four different NTCP (Normal Tissue Complication Probability) models to prospectively collected data on short-term pulmonary complications following breast cancer radiotherapy (RT). MATERIALS/METHODS: Four hundred and seventy-five breast cancer patients, referred to the Radiotherapy Department at Stockholm S?der Hospital (1994-1998) for adjuvant post-operative RT were prospectively followed for pulmonary complications 1, 4 and 7 months after the completion of RT. Eighty-seven patients with complete dose-volume histogram (DVH) of the ipsilateral lung were selected for the present analysis. Mean dose to the ipsilateral lateral lung ranged from 2.5 to 18Gy (median 12Gy). Three different endpoints were considered: (1) clinical pneumonitis scored according to CTC-NCIC criteria: asymptomatic (grade 0) vs grade 1 and grade 2; (2) radiological changes assessed with diagnostic chest X-ray: no/slight radiological changes vs moderate/severe; (3) radiological changes assessed with CT: no/slight vs moderate/severe. Four NTCP models were used: the Lyman model with DVH reduced to the equivalent uniform dose (LEUD), the Logit model with DVH reduced to EUD, the Mean Lung Dose (MLD) model and the Relative Seriality (RS) model. The data fitting procedure was done using the maximum likelihood analysis. The analysis was done on the entire population (n=87) and on a subgroup of patients treated with loco-regional RT (n=44). RESULTS: 24/87 patients (28%) developed clinical pneumonitis; 28/81 patients (35%) had radiological side effects on chest X-rays and 11/75 patients (15%) showed radiological density changes on Computed Tomography (CT). The analysis showed that the risk of clinical pneumonitis was a smooth function of EUD (calculated from DVH using n=0.86+/-0.10, best fit result). With LEUD, the relationship between EUD and NTCP could be described with a D(50) of 16.4Gy+/-1.1Gy and a steepness parameter m of 0.36+/-0.7. The results found in the overall population were substantially confirmed in the subgroup of patients treated with loco-regional RT. CONCLUSIONS: A large group of prospective patient data (87 pts), including grade 1 pneumonitis, were analysed. The four NTCP models fit quite accurately the considered endpoints. EUD or the mean lung dose are robust and simple parameters correlated with the risk of pneumonitis. For all endpoints the D(50) values ranged in an interval between 10 and 20Gy.     

VMAT下肺等效均匀剂量预测RP价值研究

目的 对VMAT下基于肺等效均匀剂量的放射性肺炎预测价值的临床应用效果进行评价及最优化a值的搜寻。 方法 选取2015—2016年间接受过VMAT的 65例肺癌患者,根据放疗结束后有无RP分成两组,导出DVH等信息,用自编数值分析程序进行数据分析。分别计算a在-50~50区间两组肺等效均匀剂量值变化,找出两组相对肺等效均匀剂量值差距最大的a值。采用成组t检验对发生和未发生放射性肺炎的 V₅、V₂₀、V₃₀、MLD和肺等效均匀剂量(a_optimal)进行分析;采用Pearson相关分析法分析V_dose和肺等效均匀剂量(a_optimal)与RP之间关系;采用 Logistic回归方法建立疾病预测模型。 结果 a=0.3时发生和未发生组肺等效均匀剂量相对差取得最大值(627.94 cGy和510.23 cGy,相对剂量差 R=23.07%)。相对差R在-50~-5区间缓慢减少,在-5~0急剧增加且在a=0.3时取得最大值;在a从 0.3~4.0区间快速减小后直到研究终点50都趋于缓慢减小趋势。传统物理容积剂量阈值相关性分析也提示肺等效均匀剂量(a=0.3时)和 V₅、V₁₀、V₂₀、MLD有相关性(r=0.929,P<0.05)。 结论 采用VMAT技术进行胸部肿瘤放疗患者,肺等效均匀剂量(a=0.3时)能较好区分有无肺炎两组,建议肺等效均匀剂量限制在510 cGy内,肺等效均匀剂量和常规物理剂量相结合对非均匀照射条件下RP有一定临床预测价值。     

Ⅲ＋Ⅳ期非小细胞肺癌调强放疗剂量学参数预测有症状放射性肺炎的临床研究

目的：探讨接受调强放疗（intensity modulated radiotherapy,IMRT）的Ⅲ、Ⅳ期非小细胞肺癌（non－small－cell lung cancer,NSCLC）患者正常肺组织剂量－体积参数对有症状放射性肺炎（≥2级,radiation pneu-monitis,RP）的预测作用。方法：回顾性分析53例接受调强放疗的Ⅲ、Ⅳ期NSCLC患者临床资料,记录剂量－体积参数V5、V20、平均肺剂量（MLD）及≥2级RP发生率。肺损伤评估根据CTCAE4．0标准。单因素及多因素分析各个剂量学参数与≥2级RP之间的关系,并采用ROC曲线分析各剂量参数的敏感性、特异性对预测≥2级RP的价值。结果：53例患者中2级RP发生率为9．43％（5／53）,3级RP发生率为5．66％（3／53）,4级RP发生率为3．77％（2／53）,≥2级RP总发生率为18．87％（10／53）。经Spearman等级相关分析,V5、V20、MLD均与≥2级RP的发生相关（r＝0．485、0．404、0．404,P＝0．000、0．003、0．003）。单因素分析发现V5、V20、MLD与≥2级RP的发生有相关性（t＝－4．588、－2．433、－2．845,P＝0．000、0．019、0．006）。经单因素分析中有意义的参数,再次进行多因素分析显示：V5是≥2级RP发生的独立影响因素（P＝0．03）。经ROC曲线分析,V5预测≥2级RP有统计学意义（P＜0．05）,其曲线下面积为0．862,敏感性和特异性分别为1．00、0．442。当V5临界值为43．65％时≥2级RP发生率分别为7．14％、32％。结论：剂量－体积参数V5、V20、MLD与≥2级RP相关,其中V5是独立预测因素。     

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.     

非小细胞肺癌三维适形放疗放射性肺损伤剂量学因素分析

目的 观察非小细胞肺癌三维适形放疗患者急性放射性肺炎的发生情况,并分析其与各剂 量学因素的关系。方法 收集2010年6月—2010年12月间首程行三维适形放疗的非小细胞肺癌患者68 例。从治疗计划系统的剂量体积直方图中获取以下剂量学参数：处方剂量、平均肺剂量(MLD)、正常 肺体积剂量（V5~V50间隔5 Gy）等,分别采用单因素及多因素分析各个剂量学参数与放射性肺炎之 间的关系,并采用受试者工作特征曲线寻找预测界值。结果 V5是放射性肺炎发生的独立预后因素 （χ2=5.15,P=0.023）。患者肺脏的V5超过57%时放射性肺炎的发生率可能会增加。结论 临床医师 在审核治疗计划时,除了要考虑V20、V30、MLD等常用参数外,还应关注V5的大小。     

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。     

Final toxicity results of a radiation-dose escalation study in patients with non-small-cell lung cancer (NSCLC): predictors for radiation pneumonitis and fibrosis

PURPOSE: We aimed to report the final toxicity results on a radiation-dose escalation trial designed to test a hypothesis that very high doses of radiation could be safely administered to patients with non-small-cell lung cancer (NSCLC) by quantifying the dose-volume toxicity relationship of the lung. METHODS AND MATERIALS: A total of 109 patients with unresectable or medically inoperable NSCLC were enrolled and treated with radiation-dose escalation (on the basis of predicted normal-lung toxicity) either alone or with neoadjuvant chemotherapy by use of 3D conformal techniques. Eighty-four patients (77%) received more than 69 Gy, the trial was stopped after the dose reached 103 Gy. Estimated median follow-up was 110 months. RESULTS: There were 17 (14.6%) Grade 2 to 3 pneumonitis and 15 (13.8%) Grade 2 to 3 fibrosis and no Grade 4 to 5 lung toxicity. Multivariate analyses showed them to be (1) not associated with the dose prescribed to the tumor, and (2) significantly (p<0.001) associated with lung-dosimetric parameters such as the mean lung dose (MLD), volume of lung that received at least 20 Gy (V20), and the normal-tissue complication probability (NTCP) of the lung. If cutoffs are 30% for V20, 20 Gy for MLD, and 10% for NTCP, these factors have positive predictive values of 50% to 71% and negative predictive value of 85% to 89%. CONCLUSIONS: With long-term follow-up for toxicity, we have demonstrated that much higher doses of radiation than are traditionally administered can be safely delivered to a majority of patients with NSCLC. Quantitative lung dose-volume toxicity-based dose escalation can form the basis for individualized high-dose radiation treatment to maximize the therapeutic ratio in these patients.     

肺低剂量区体积预测胸中下段食管癌放射性肺炎的价值

目的 明确肺低剂量区体积在预测接受放射治疗的胸中下段食管癌患者出现急性放射性肺炎（radiation pneumonitis, RP）的价值。方法 对205例接受放射治疗并符合入组条件的胸中下段食管癌患者发生RP的情况进行分析,对患者临床资料和治疗计划等指标进行单因素及多因素分析,评价肺低剂量区体积指标的价值。结果 全组患者出现≥2级RP的患者为60例占29.27%（60/205）,其中2级48例（23.41%）,3级10例（4.88%）,4级2例（0.98%）。单因素分析结果显示食管癌病变X 线长度、GTV最大横径、GTV长度、射野数、肺MLD、GTV体积、PTV体积、肺V5、肺V10和肺V15均影响患者≥2级RP的发生。多因素分析结果显示射野数、肺MLD及肺V5为患者≥2级RP发生的独立预测影响因素。ROC曲线分析结果显示本组患者肺V5取值为51.17%为预测放射性肺炎的效能值。结论 肺低剂量区体积V5为接受放疗的胸中下段食管癌患者发生≥2级RP的重要预测因素,建议在以后制定胸中下段食管癌的放射治疗计划时应该予以重视,取值应≤51.17%。