非小细胞肺癌三维适形后程加速超分割放疗中肺剂量体积变化规律及临床意义探讨

目的 分析肺癌前、后程三维适形计划中正常肺剂最体积直方图变化及其与两程计划合成结果比较,探讨正常肺剂量体积直方图变化规律及放疗中靶区修改的可行性.方法 选择21例接受三维适形后程加速超分割放疗的非小细胞肺癌病例,设定首程(P1)、后程(P2)三维适形计划的处方剂量均为70 Gy,V20≤35%.将P.按常规分割照射40 Gy后,重新定位并修改靶区后设计P2,加速超分割照射30 Gy.将P1靶区、射野和剂量(MU)等物理参数导入P2CT定位图像中,与之合成得到70 Gy合成计划(Pc);计算首程和后程总肺体积、靶体积(GTV、PTV),计算首程、后程和合成计划中MLD、V5、V10、V20、V30.分析3种计划中各项指标变化规律,并单因素相关分析MLD和V20.结果 前、后两程计划总肺体积无明显变化(t=0.19,P=0.850),后程GTV、PTV较首程明显缩小(t=2.88,P=0.009;t=4.01,P=0.001).全组P2、P1的正常肺MLD分别为16.5、17.8 Gy(t=2.60,P=0.017)、V30显著降低(t=2.19,P=0.041);但V5、V10、V20相似.Pc较P1的肺MLD、V5、V10、V20、V30均相似.Pc较P2的肺MLD、V5、V10、V20、V30均明显增加.分层分析PTV缩小的14例患者P2、P1的V30、MLD显著降低(t=3.00,P=0.010;t=2.38,P=0.033),其中7例后程按首程射野数和相似入射角设计计划时V10、V30显著减小(t=2.76,P=0.033;t=3.60,P:0.011);Pc与P1比较各项指标相似,与P2比较明显增高.7例相差1～2射野和不同入射角的P1、P2和Pc之间各项指标相似.PTV不变或增大的7例P1和P2间各项指标也相似.PTV增大或缩小显著影响MLD和V20(r=-0.62,P=0.03;r=0.48,P=0.029).结论 非小细胞肺癌在三维适形后程加速超分割放疗过程中肿瘤明显缩小时,修改靶区及计划可降低正常肺高剂量体积,如按相同射野方向时可能缩小正常肺低剂量体积.后程计划设计物理参数应与首程相似,融合计划评估全程计划正常肺剂量体积直方图比较合理.     

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。     

血浆白细胞介素6、血管紧张素转换酶水平及放射剂量体积直方图参数对放射性肺炎预测的临床价值

 目的　研究血浆中白细胞介素6（IL-6）、血管紧张素转换酶（ACE）水平及剂量体积直方图（DVH）参数与放射性肺炎发生的相关性,并评价其在预测放射性肺炎中的临床价值。方法　常规给予60例不能手术切除或者不愿意手术切除的局部晚期非小细胞肺癌患者三维适形放疗。分别在放疗前、放疗中（放疗第1周至第6周）、放疗后（放疗第8、12周）采用酶联免疫吸附法（ELISA）检测血浆中IL-6及ACE的含量。 依照美国放射肿瘤学协作组（RTOG）放射性肺损伤标准进行放射性肺炎诊断及分级,以出现放射性肺炎组为观察组,未出现放射性肺炎组为对照组,统计两组血浆中IL-6、 ACE、DVH参数V20、V30、平均肺剂量（MLD）及正常组织并发症概率（NTCP）。结果　60例患者中16例发生放射性肺炎,其中5例发生于放疗中,10例发生于放疗结束后1个月内,1例发生于放疗结束后2个月内;包括Ⅱ级11例,Ⅲ级5例。放疗前、中、后血浆IL-6水平变化在观察组与对照组间差异均有统计学意义,ACE在放疗中第3周至第6周两组间差异有统计学意义（均P＜0.05）。V20、V30、MLD及NTCP在观察组与对照组分别为（46.2±4.5）%比（30.5±7.5）%、（37.5±5.6）%比（20.5±5.6）%、（20.4±2.3）Gy比（15.5±3.5）Gy、（25.2±8.2）%比（9.9±4.5）%,两组间差异有统计学意义（均P＜0.05）。结论　血浆中IL-6、ACE水平、V20、V30、MLD及NTCP指标均与放射性肺炎的发生有关。     

经调强适形放疗治疗的肺癌患者发生放射性肺炎的相关因素分析

 目的　探讨调强适形放疗（IMRT）治疗肺癌发生放射性肺炎（RP）的相关因素,寻找合理的预测性指标,为放疗计划的制定提供参考。方法　对163例经IMRT治疗肺癌患者的临床资料及剂量-体积直方图的相关参数进行量化分析,放疗结束后随访时间≥6个月,应用统计学方法研究其与RP之间的关系。结果　≥2级RP的发生率为28.22 %（46／163）。单因素分析发现下叶肿瘤（P＝0.033）、合并慢性阻塞性肺疾病（COPD）（P＝0.020）、联合化疗（P＝0.020）、未预防性使用糖皮质激素及抗生素（P＝0.025）与RP的发生有关。其中肺基础疾病及联合化疗是影响≥2级RP发生的独立因素。多因素分析表明健侧肺V20、全肺V5及靶区总体积是RP发生的独立影响因素。结论　RP的发生与多种因素相关,放疗计划应根据患者的具体情况合理地制定。     

肺低剂量区体积与非小细胞肺癌放疗致放射性肺损伤的关系

目的 探讨肺低剂量区体积剂量学参数与非小细胞肺癌（non small cell lung cancer,NSCLC)放疗致放射性肺损伤（radiation induced lung injury,RILI）的关系。方法 收集103例NSCLC放疗患者,通过放疗计划及剂量体积直方图（DVH）获得全肺、患侧肺、健侧肺的剂量体积参数和平均肺受照射剂量（MLD）,采用单因素分析各剂量学参数与≥2级RILI发生的相关性,制作受试者工作特征曲线（ROC）,评价各剂量学参数对RILI的预测价值。结果 发生≥2级RILI 者27例,发生率为26.2%。≥2级RILI患者双肺V₅、双肺MLD、患侧肺V₅、患侧肺V₁₀、健侧肺V₅的相对肺体积均高于＜2级RILI者,差异均有统计学意义（P＜0.05）。ROC曲线分析显示,双肺V₅、双肺MLD、患侧肺V₅、患侧肺V₁₀、健侧肺V₅曲线下面积分别为0.714、0.673、0.690、0.693、0.737,当双肺V₅≥52.22%、双肺MLD≥1 486.75 cGy、患侧肺V5≥62.03%、健侧肺V5≥43.60%、患侧肺V10≥55.67%均可导致肺癌患者≥2级RILI发生率升高（P＜0.001）。 结论 临床制定NSCLC患者根治性放疗计划时,不仅要限定V₂₀、V₃₀、MLD,还应注意低剂量区体积V5对放射性肺损伤的影响。     

肺脏低剂量区体积预测食管癌三维适形放疗所致急性放射性肺炎的价值

目的 探讨肺脏低剂量区体积预测食管癌单纯三维适形放疗(3D-CRT)所致急性放射性肺炎(RP)的价值,并确定肺脏V5(接受5Gy照射时的肺脏体积占全肺总体积的百分比)与双侧肺脏受照平均肺剂量(MLD)和肺脏V20不同组合预测RP发生的最优组合.方法 选取接受单纯根治性3 D-CRT的食管癌患者222例,观察并记录双侧肺脏接受5、10、15、20、25和30 Gy照射时的肺脏体积占全肺总体积的百分比(V5、V10、V15、V20、V25、V30)和双侧肺脏MLD,对患者临床资料和治疗计划等进行单因素和多因素分析.结果 222例患者中,发生1级急性RP者68例(30.6％)、2级40例(18.0％)、3级8例(3.6％)、4级1例(0.5％).单因素分析结果显示,射野数、大体肿瘤体积、双侧肺脏MLD、肺脏V5、V10、V15、V20、V25和V30均与≥1级和≥2级急性RP的发生有关(均P＜0.05).多因素分析结果显示,双侧肺脏MLD、肺脏V5、V20和V25为食管癌患者发生≥1级急性RP的独立影响因素(均P＜0.05);射野数、双侧肺脏MLD和肺脏V5为食管癌患者发生≥2级急性RP的独立影响因素(均P ＜0.05).以双侧肺脏MLD、肺脏V5和V20的分界值(分别为14 Gy、60％和28％)进行不同组合,当患者双侧肺脏MLD≤14 Gy+肺脏V5≤60％+V20≤28％时,≥1级和≥2级急性RP的发生率均减低(均P ＜0.05);当肺脏V20≤28％+ V5≤60％时,≥1级和≥2级急性RP的发生率均减低(均P ＜0.05);当双侧肺脏MLD≤14 Gy+V5≤60％时,≥1级急性RP的发生率减低(P＜0.05);当双侧肺脏MLD＞ 14 Gy+V5≤60％时,≥2级急性RP的发生率减低(P＜0.05).结论 肺脏低剂量区体积与食管癌单纯3D-CRT所致急性RP的发生密切相关;双侧肺脏MLD、肺脏V5和V20组合有可能提高预测急性RP发生的能力.     

直肠癌术后IMRT中降低CTV上界的剂量学获益研究

摘 要：［目的］ 探讨直肠癌术后调强适形放疗（IMRT）中降低CTV上界的剂量学获益,为直肠癌放疗中CTV最新国际勾画指南的临床应用提供剂量学依据。［方法］ 对10例Ⅱ期直肠癌术后放疗患者分别进行7野IMRT计划设计,对照组CTV靶区上界为L5/S1,研究组CTV靶区上界为S1-S2,两组计划统一给予高危复发区域和区域淋巴引流区（PTV）50 Gy剂量分25次照射。利用剂量体积直方图评价靶区剂量分布以及危及器官的照射剂量。［结果］ 两组计划的靶区剂量差异无统计学意义。研究组计划的小肠V15-V45较对照组均明显降低,其中V15降低了20.32%（311.60cc vs 248.29cc,P=0.004）;研究组计划骨盆的V10、V20、Dmean剂量分别降低了8.61%、8.42%、7.39% (P均<0.05)。对照组和研究组的机器跳数分别为670.10±113.95 MU和612.50±105.67 MU（t=2.207,P=0.055）。［结论］ 直肠癌术后放疗中将CTV靶区上界降低至S1-S2可明显降低小肠和骨盆剂量,其疗效还需进一步临床评估。     

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%。     

非小细胞肺癌中两种不同放疗技术的剂量学及临床疗效对比

摘 要：［目的］ 对比研究非小细胞肺癌（NSCLC）放疗中调强放疗（IMRT）与三维适形放疗（3D-CRT）对靶区及危及器官的剂量学的影响。［方法］ 选取2015年5月至2016年12月NSCLC患者90例进行CT检测,据其CT定位图像分别设计IMRT及3D-CRT两种计划。据放疗方法的不同将患者分为IMRT组（n=45）及3D-CRT组（n=45）,两种放疗计划的处方剂量均为64 Gy/32 f照射,并可满足靶区及关键器官的剂量要求。［结果］ IMRT组放射性食管炎发生率（13.33%）及放射性肺炎发生率（28.89%）均显著性低于3D-CRT组的31.11%及53.33%（P<0.05）,而两组间临床缓解率（RR）无显著性差异（P>0.05）。与3D-CRT组比较,IMRT组靶区剂量均匀性（HI）显著性降低（P<0.01）,而靶区最大剂量（PTV Dmax）、靶区最小剂量（PTV Dmin）、靶区平均剂量（PTV Dmean）及靶区适形度（CI）显著性升高（P<0.01）;与3D-CRT组比较,IMRT组肺V5显著性升高,而肺V20、肺V30及平均肺剂量（MLD）均显著性降低（P<0.01）,两组间肺V10无显著性差异（P>0.05）。与3D-CRT组比较,IMRT组脊髓最受量（Dmax）、脊髓平均受量（Dmean）、心脏V35、食管V50及食管V60均明显降低（P<0.01）。［结论］ IMRT与3D-CRT对NSCLC患者的临床疗效相近,但IMRT计划靶区剂量分布更加合理,可在提高靶区剂量的同时,减轻放疗的毒副作用,更好地保护周围正常组织。     

食管中段癌三维适行放疗与旋转拉弧适形放疗剂量学比较

摘 要：［目的］ 分析食管中段癌三维适形放疗（3D-CRT）和旋转拉弧适形放疗（RapidArc-SBRT）2种放疗技术的剂量学特点。［方法］ 收集9例食管中段癌放疗患者,分别设计3D-CRT和RapidArc-SBRT放疗计划;绘制出PTV的DVH示意图;比较各计划靶区适形指数（CI）、均匀指数（HI）以及机器跳数（MU）;计算双肺的V5、V20及平均受量Dmean,脊髓最大受量,比较两种照射方式的优劣。［结果］ 3D-CRT的CI值为0.61±0.04,HI为1.12±0.05,最大剂量（6872±528）cGy,机器跳数289±11,左肺V5为56.2%±18.9%,V20为26.3%±6.1%,Dmean为（1203±272）cGy,右肺V5为58.3%±14.0%,V20为24.8%±7.2%,Dmean为（1191±399）cGy,脊髓为（2463±1399）cGy。RapidArc-SBRT的CI值为0.65±0.05,HI为1.10±0.04,最大剂量（6691±522）cGy,机器跳数292±15,左肺V5为69.8%±24.8%,V20为15.0%±12.6%,Dmean为（1155±467）cGy,右肺V5为70.2%±22.4%,V20为13.2%±14.4%,Dmean为（1130±574）cGy,脊髓为（3553±652）cGy。［结论］ RapidArc-SBRT剂量分布、靶区适形度、剂量均匀性要优于3D-CRT。     

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。     

Prediction of radiation pneumonitis by dose - volume histogram parameters in lung cancer--a systematic review.

BACKGROUND AND PURPOSE: To perform a systematic review of the predictive ability of various dose-volume histogram (DVH) parameters (V(dose), mean lung dose (MLD), and normal tissue complication probability (NTCP)) in the incidence of radiation pneumonitis (RP) caused by external-beam radiation therapy. METHODS AND MATERIALS: Studies assessing the relationship between CT-based DVH reduction parameters and RP rate in radically treated lung cancer were eligible for the review. Synonyms for RP, lung cancer, DVH and its associated parameters (NTCP, V(20), V(30), MLD) were combined in a search strategy involving electronic databases, secondary reference searching, and consultation with experts. Individual or group data were abstracted from the various reports to calculate operating characteristics and odds ratios for the different DVH metrics. RESULTS: A total of 12 published studies and two abstracts were identified. Eleven studies assessed V(dose), seven assessed MLD, and eight assessed NTCP. Nine studies exclusively analyzed the association between various DVH metrics and RP risk. Five studies also analyzed other patient, tumor, and treatment variables in conjunction with standard DVH metrics. A direct comparison between studies and the generation of summary statistics (i.e. meta-analysis) could not be achieved due to significant predictive and outcome variable heterogeneity. Most studies did show an association between DVH parameters and RP risk. However, overall accuracy, sensitivity, specificity, and positive predictive value were generally poor to fair for all three classes of DVH metrics. CONCLUSIONS: An association between DVH parameters and RP risk has been demonstrated in the literature. However, the ideal DVH metric with excellent operating characteristics, either alone or in a model with other predictive variables, for RP risk prediction has not yet been identified. Several recommendations for reporting and conduct of future research into the association between DVH metrics and RP risk are provided.     

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.     

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。     

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.     

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。     

肺灌注显像联合剂量体积直方图参数预测放射性肺炎的临床研究

 目的　观察接受三维适形或调强放疗的肺癌患者放疗前后肺灌注显像的变化、肺受照射的剂量体积直方图（DVH）参数等,并结合临床因素,探讨其与放射性肺炎发生的相关性。方法　18例接受三维适形或调强放疗的肺癌患者放疗前后行肺灌注显像检查,比较照射前后肺灌注显像的变化。放射性肺炎的评价按美国肿瘤放疗协作组（RTOG）急性放射性肺炎标准评定。获得的CT与单光子发射CT（SPECT）肺灌注图像融合后,将等剂量曲线投影到SPECT图像,将传统的DVH转换成f-DVH。将f-DVH曲线中每例患者的V5、V10和V20所对应的灵敏度与特异度相加,取其最大值,寻找到曲线的界值。分析放疗前后肺灌注显像变化及肺受照射的DVH与放射性肺炎发生的相关性。结果　18例患者中,33.3 %（6／18）发生了2级以上放射性肺炎。放疗前后肺灌注受损加重者2级以上放射性肺炎发生率为62.5 %（5／8）,肺灌注受损改善者发生率为10.0 %（1／10）。f-DVH图曲线中V5、V10和V20的界值分别为53 %、41 %和27 %,以V5对中重度急性放射性肺炎的预测准确度最高。放疗前后肺灌注显像的变化联合全肺DVH参数V5是放射性肺炎最强的预测因素。结论　肺癌患者放疗前后肺灌注显像能反映患侧肺灌注功能的变化。放疗前后肺灌注显像的变化联合DVH参数V5有望作为预测放射性肺炎发生的指标。