固定野调强放疗对局部晚期肺癌放射性肺炎的影响

放射性肺炎(RP)是胸部放射治疗最主要的剂量限制性不良反应.三维适形放疗(3D-CRT)能够使靶区剂量分布与靶区形状保持一致,靶区周围危及器官暴露体积减少,有可能使患者生存获益[1].固定野调强放疗(IMRT)较3D-CRT进一步提高靶区的剂量学参数,满足靶区剂量分布的需要,更好地避免对危及器官的照射,有助于提升靶区剂量[2-3],即IMRT降低高剂量区参数(如双肺V20和V30)的同时可能会增加低剂量区参数(如双肺V5).早期研究发现V20和V30与RP发生风险相关[4],近年来发现V5与RP也具有显著相关性[5].本研究以3D-CRT为比较,回顾分析了IMRT对RP发生率的影响.     

胸部肿瘤三维适形放疗所致放射性肺炎影像学表现及病因分析

目的:探讨胸部肿瘤三维适形放疗(3D-CRT)所致放射性肺炎(RP)的影像学表现及发生的相关因素。方法:对28例三维适形放疗所致RP患者胸部影像学征象进行评定,并通过临床观察对RP的相关因素进行分析。结果:97例胸部肿瘤放疗患者中发生RP 28例,发生率28.87%。在各临床指标中,吸烟患者、肿瘤位于双肺上叶的患者发生概率较高。在剂量学指标中,单因素分析显示受到20、30、40Gy剂量照射的肺体积占全肺总体积的百分比(V20、V30、V40)、全肺平均剂量(MLD)与RP相关。结论:CT诊断RP较X线敏感,有特征表现,而且对肺炎的不同时期可作出正确判断。肺炎的发生因素,除放疗技术外,个人体质、吸烟、手术等都有影响。     

容积旋转调强放疗和常规调强放疗技术在乳腺癌保乳术后同步推量中的剂量学比较

 目的 比较容积旋转调强放疗(VMAT)和常规调强放疗(IMRT)两种技术在乳腺癌保乳术后同步推量放疗中剂量学差异。方法 随机选择10例左侧乳腺癌保乳术后患者,使用MONACO 5.1计划系统,分别设计VMAT和IMRT计划,处方剂量均为PTV_50Gy/25 f、PGTVtb60 Gy/25 f,评估两种计划靶区剂量适形指数(CI)、均匀性指数(HI),以及正常器官受照剂量(Gy)、机器跳数(MU)及治疗时间。结果 VMAT计划中靶区剂量的适形度明显优于IMRT(P<0.05),而患侧肺V₅、V₁₀、V₂₀及健侧肺V₅稍高于IMRT组(P<0.05)。结论 对于乳腺癌保乳术后同步推量放疗,VMAT和IMRT计划都可以满足临床剂量学的要求,VMAT在适形度方面对于IMRT计划有优势,并缩短了治疗时间。     

大体肿瘤靶体积/肺体积预测Ⅲ期非小细胞肺癌根治性放疗后放射性肺炎的发生风险

目的 分析接受根治性放疗的Ⅲ期非小细胞肺癌患者放射性肺炎(radiation pneumonitis, RP)发生相关的临床、剂量学因素。方法 回顾性分析北京大学肿瘤医院放疗科2013年1月至2014年12月收治的126例接受胸部根治性放疗的Ⅲ期非小细胞肺癌患者,统计性别、年龄、病理类型、肿瘤位置、糖尿病史、高血压病史、吸烟史、治疗开始季节、治疗前体力状况(采用美国东部肿瘤协作组ECOG评分)、放疗前化疗方案、同步化疗方案、放射性肺炎分级等临床因素,以及GTV体积、肺体积(lung volume, LV)、全肺V₅、V₁₀、V₂₀、V₃₀、平均肺剂量(MLD)等剂量学参数。对各因素与2级以上放射性肺炎(RP≥2)进行相关性分析。结果 126例患者中发生≥2级放射性肺炎者31例,占24.6%。单因素分析显示,年龄、治疗前ECOG评分、同步化疗方案、GTV/LV比值与≥2级RP具有相关性(R=0.157~0.222,P<0.05);多因素分析显示,年龄、同步化疗方案、GTV/LV比值与≥2级RP发生显著相关(Wald=4.754、6.422和14.79,P<0.05)。结论 Ⅲ期非小细胞肺癌患者接受胸部根治性放疗时,年龄增加和GTV/LV比值≥3.2%是≥2级RP发生的危险因素;同步使用单药小剂量紫杉醇也可能导致放射性肺炎发生危险增加。     

基于海马保护的2种儿童中枢神经系统生殖细胞肿瘤放疗技术的剂量学研究

目的 比较容积旋转调强放射治疗（VMAT）和调强适形放射治疗（IMRT）2种技术在儿童中枢神经系统（CNS）生殖细胞肿瘤（GCT）放疗中的海马保护和剂量学差异。 方法 回顾性分析2020年6月至2021年6月在解放军联勤保障部队第九〇〇医院接受全CNS放疗的12例GCT患儿的影像学资料,其中男性患儿4例、女性患儿8例,年龄7~14岁,中位年龄11岁。对所有患儿进行靶区及周围危及器官的勾画,分别设计VMAT计划和IMRT计划,处方剂量30 Gy,每次3 Gy,共照射10次。通过剂量体积直方图获取各剂量学参数并进行配对t检验,比较靶区及周围危及器官的剂量学差异,通过比较机器跳数和治疗时长评估计划实施效率。 结果 VMAT和IMRT 2种技术均能得到较好的靶区剂量学分布。VMAT技术的靶区均匀性略优于IMRT技术,均匀性指数分别为0.11±0.02和0.14±0.01,且差异有统计学意义（t=?5.392,P<0.001）。VMAT和IMRT2种技术的左海马最大照射剂量分别为（15.99±0.70） Gy和（21.21±1.07） Gy、右海马最大照射剂量分别为（16.13±0.58） Gy和（21.35±0.69） Gy,且差异均有统计学意义（t=?17.622、?21.628,均P<0.001）,VMAT技术在海马保护上达到了剂量限制要求。VMAT技术在周围危及器官保护方面较IMRT技术优势明显,除双肺外,在眼晶状体、甲状腺、肾脏保护方面VMAT技术全面优于IMRT技术,且差异均有统计学意义（t=?8.198~?2.231,均P<0.05）。VMAT技术在治疗效率方面同样优于IMRT技术,VMAT的机器跳数为1 749±95、治疗时长为（354±31） s,均仅为IMRT技术的40%左右,且差异均有统计学意义（t=?20.883、?22.790,均P<0.001）。 结论 在儿童CNS GCT放疗中,VMAT技术能够在保护海马的情况下实现更好的靶区均匀性,同时在周围危及器官保护和治疗效率上具有明显优势。     

胸段食管癌放疗后放射性肺炎相关因素分析

目的 探讨胸段食管癌患者临床特征、照射技术及肺剂量体积参数等因素对放疗后放射性肺炎（RP）的影响,为食管癌放疗方案的制定提供参考。方法 回顾性分析山东省肿瘤防治研究院山东省肿瘤医院山东第一医科大学山东省医学科学院2014年6月至2019年6月247例胸段食管癌患者放疗后RP的发生情况,对患者临床特征、照射技术及肺剂量学参数进行单因素和多因素分析,采用受试者工作特征（ROC）曲线下的面积（AUC）分别验证≥1级、≥2级、≥3级RP的诊断效能。结果 全组患者中≥1级RP 118例（47.8%）,≥2级RP 54例（21.9%）,≥3级RP 17例（6.9%）。单因素分析结果显示,双肺V₅~V₄₀、平均肺剂量（MLD）均与≥1级RP（Z=-5.802~-4.306,P<0.05）和≥2级、≥3级RP（F=0.057~11.616、0.087~3.392,P<0.05）发生有关,GTV体积、PTV体积、GTV/肺体积（%）、PTV/肺体积（%）均与≥1级RP（Z=-3.377~-2.041,P<0.05）和≥2级RP（F=3.600~9.801,P<0.05）发生有关;吸烟指数>400与≥3级RP明显相关（χ²=13.295,P<0.05）,慢性阻塞性肺病（COPD）与≥1级RP者明显相关（χ²=9.146,P<0.05）,而不同的照射技术、化疗因素、放疗剂量以及食管癌分期、位置均与RP无显著相关。多因素分析结果显示,双肺V₅和V₄₀为≥1级RP的独立危险因素,AUC最佳临界值分别为55.74%和4.13%;MLD为≥2级RP的独立危险因素,最佳临界值为11.91 Gy;双肺V₅为≥3级RP的独立危险因素,最佳临界值为57.60%。吸烟指数>400为≥3级RP的独立危险因素（Wald＝5.964,P<0.05）,COPD为≥1级RP的独立危险因素（Wald＝6.110,P<0.05）。结论 胸段食管癌放疗后RP的发生率较低,双肺V₅、V₄₀、MLD等剂量学参数及吸烟程度和COPD等临床特征与相应等级的RP的发生密切相关,实施食管癌放疗时应重点关注。     

3种不同放疗技术在左侧乳腺癌保乳术后全乳腺放疗中的剂量学比较

目的 比较3种调强放疗技术在早期左侧乳腺癌保乳术后全乳腺放疗中的剂量学差异。 方法 回顾性分析2019年3月至8月在西安交通大学第一附属医院治疗的12例早期左侧乳腺癌保乳术后女性患者,年龄32~50（42.4±6.8）岁。分别设计基于固定角度适形调强放疗的混合调强（3DCRT+IMRT）、容积旋转调强放疗的混合调强（3DCRT+VMAT）和切线弧容积旋转调强放疗计划（t-VMAT）,并比较3种放疗计划的计划靶区、危及器官剂量参数以及治疗效率的差异。组间数据比较采用配对t检验。 结果 3种调强放疗计划的靶区剂量分布和危及器官受量均能满足临床要求。3DCRT+IMRT和t-VMAT两种计划相比,3DCRT+VMAT的靶区剂量学指标适形性指数（0.84±0.05对0.74±0.06对0.79±0.06）和均匀性指数（0.10±0.03对0.14±0.03对0.13±0.03）最优,差异均有统计学意义（t=?9.01~6.47,均P<0.05）;3DCRT+IMRT对患侧（左）肺的V₅[（35.92±8.01）%对（49.33±12.05）%对（60.58±12.94）%]、V₁₀[（25.50±6.91）%对(26.92±7.23）%对（41.25±10.37）%]、D_mean[（10.14±2.43）Gy对（11.07±2.88）Gy对（14.52±3.32）Gy]和健侧（右）肺的V₅[（0.50±1.45）%对（2.17±3.76）%对（3.00±4.94）%]、D_mean[（0.55±0.21）Gy对（1.79±0.58）Gy对1.75±0.70）Gy]及健侧（右）乳腺的V₅[（0.17±0.58）%对（1.92±4.10）%对（8.25±8.61）%]、D_mean[（0.86±0.38）%对（1.65±0.45）%对（2.46±0.86）%]的保护最好。3DCRT+VMAT的心脏V₃₀[（4.50±2.88）%对（5.00±3.25）%对（8.42±2.78）%]、V₄₀[（2.50±2.11）%对（3.25±2.53）%对（4.58±2.07）%]明显优于3DCRT+IMRT和t-VMAT,且差异均有统计学意义（t=?17.11~3.45,均P<0.05）。3DCRT+IMRT的平均机器跳数最小（280.90±52.18）,t-VMAT的治疗时间最短。 结论 3DCRT+IMRT在低剂量区（<20 Gy）对健侧肺、患侧肺,健侧乳腺等危及器官的保护比较好,3DCRT+VMAT在提高靶区的均匀性和适形性方面有明显优势,且在高剂量区（>20 Gy）对患侧肺及心脏保护更好,t-VMAT缩短了治疗时间,提高了治疗效率和患者舒适度。     

宫颈癌复发放疗中不同照射方式的剂量学研究

目的针对宫颈癌复发病例,比较逆向调强(IMRT)、三维适形(3D-CRT)及超级伽玛刀弧形适形(SGS-CRT)三种照射方式的剂量学特点。方法对15例宫颈癌复发患者进行IMRT、3D-CRT及SGS-CRT计划设计,以包绕计划靶区(PTV)体积95%的等剂量线为处方剂量线,分别给予50Gy的处方剂量,分次方案均为2Gy×25次,根据剂量-体积直方图(DVH)评价三种照射方式中靶区和危及器官的剂量学特点。结果 3D-CRT的95%处方剂量包括靶区体积(99.9%±0.2%)高于IMRT(99.5%±0.5%)及SGS-CRT(99.3%±0.8%,P<0.05);SGS-CRT的靶区剂量梯度(85%±20%)明显高于IMRT(10%±7%)及3D-CRT(8%±5%,P<0.05);IMRT的适形指数(0.9±0.3)优于SGS-CRT(0.8±0.2,P<0.05),且SGS-CRT优于3D-CRT(0.7±0.5,P<0.05)。DVH显示,在10~30Gy之间,SGS-CRT膀胱平均受照体积(27.8%)明显低于IMRT(40.1%)和3D-CRT(57.4%,P<0.05);在5~45Gy之间,直肠平均受照射体积SGS-CRT(25.4%)明显低于IMRT(48.9%)和3D-CRT(73.2%,P<0.05);在小肠剂量分布上,三种照射方式无显著差异。结论在宫颈癌复发放疗中,SGS-CRT具有一定剂量学优势,值得在临床应用中进一步探讨。     

宫颈癌术后调强放疗中骨髓抑制与骨髓照射剂量体积的关系

目的 观察宫颈癌患者术后三维适形调强放疗（IMRT）过程中骨髓抑制程度与骨髓照射剂量及体积的关系。 方法 收集 2013年1月至2016年1月中国人民解放军联勤保障部队第九〇〇医院放疗科收治的宫颈癌根治术后行全盆腔IMRT的患者109例,按随机数字表法将患者分为对骨髓进行限量的IMRT（BMS-IMRT）组[共56例（其中,行单纯放疗的有31例,行同步放化疗的有25例）,年龄（43.03±4.49）岁]和未限量的IMRT组[共53例（其中,行单纯放疗的有21例,行同步放化疗的有32例）,年龄（42.72±5.23）岁],2组均在放疗计划系统勾画照射范围内的骨髓,包括腰骶椎、髂骨、坐骨、耻骨及近端的股骨。观察2组患者治疗计划靶区剂量分布情况、骨髓照射体积与剂量及放疗过程中骨髓照射体积、剂量与骨髓抑制程度的关系。2组间的计划靶体积剂量学、危及器官剂量体积参数的比较采用t检验;骨髓抑制程度、白细胞计数（WBC）和中性粒细胞减少程度及其他不良反应情况比较采用χ2检验。 结果 宫颈癌患者术后IMRT过程中骨髓抑制程度与骨髓照射体积、照射剂量相关,BMS-IMRT组与IMRT组计划靶体积剂量学比较,差异无统计学意义（t=?4.220~2.923,均P>0.05）,在2组危及器官剂量体积参数对比中,骨髓的V₂₀（≥20 Gy体积占总体积的百分比）、V₄₀（≥40 Gy体积占总体积的百分比）,直肠V₄₅（≥45 Gy体积占总体积的百分比）、D_2%（近似最大剂量）及小肠D_2%比较,差异均有统计学意义（t=?12.696~2.917,均P< 0.05）。2组间WBC及中性粒细胞的减少程度比较,差异有统计学意义（χ2=6.728、6.813,P=0.035、0.033）,血小板、RBC及血红蛋白的减少程度比较,差异无统计学意义（χ2=0.385、0.006、1.419,P=0.825、0.938、0.492）。对于行单纯放疗的患者,2组的WBC减少程度比较,差异有统计学意义（χ2=9.709,P=0.008）,而对于行同步放化疗的患者,2组的WBC减少程度比较,差异无统计学意义（χ2=0.073,P=0.786）。中性粒细胞减少的程度无论是在行单纯放疗还是行同步放化疗的患者中,2组之间的差异均无统计学意义（χ2=4.741、1.523,P=0.093、0.217）,2组患者其他不良反应情况比较,差异均无统计学意义（χ2=0.369、1.845、1.158、0.610,P=0.544、0.398、0.560、0.558）。 结论 宫颈癌患者术后在行全盆腔IMRT的过程中,WBC和中性粒细胞减少程度与骨髓照射剂量及体积呈正相关,在行IMRT时应对骨髓进行保护及限量。     

胸中段食管癌适形调强放疗和三维适形放疗方案的应用探讨

目的比较胸中段食管癌适形调强放疗(IMRT)和三维适形放疗(3D-CRT)两种不同技术中计划靶区(PTV)及正常组织的受量。方法对52例ⅡB-Ⅳ期胸中段食管癌患者用同一放疗计划系统分别设计IMRT和3D-CRT根治性放疗计划,应用剂量体积直方图(DVH)比较两种方法中计划靶区和正常组织受量并且计算计划靶区适形指数(CI)和剂量不均匀指数(HI)。结果 IMRT方法的PTV适形度优于3D-CRT;脊髓剂量的最大值低于3D-CRT,但无统计学差异;心脏接受V25和V40的体积百分比低于3D-CRT;IMRT显著降低了肺部V10和V20的有效体积,但其肺部的V5大于3D-CRT。结论在可接受的放射性损伤的基础上,IMRT技术较3D-CRT能够提高行根治性放疗的ⅡB-Ⅳ期胸中段食管癌患者靶区剂量,靶区适形度高,但可使肺组织受到更大容积的低剂量照射。     

Dose-volumetric parameters for predicting severe radiation pneumonitis after three-dimensional conformal radiation therapy for lung cancer

PURPOSE: To retrospectively evaluate dose-volumetric parameters for association with risk of severe (grade >/=3) radiation pneumonitis (RP) in patients after three-dimensional (3D) conformal radiation therapy for lung cancer. MATERIALS AND METHODS: The study was approved by the institutional review board, which did not require informed consent. Data from 76 patients (66 men, 10 women; median age, 60 years; range, 35-79 years) with histologically proved lung cancer treated curatively with 3D conformal radiation therapy between August 2001 and October 2002 were retrospectively analyzed. Twenty patients underwent surgery before radiation therapy; 57 patients received chemotherapy. Median total radiation dose of 60 Gy (range, 54-66 Gy) was delivered in 30 (range, 27-33) fractions over 6 weeks. RP was scored by using Radiation Therapy Oncology Group criteria. Clinical parameters were analyzed. Dose-volumetric parameters analyzed were percentage of lung volume that received a dose of 20 Gy or more (V20), 30 Gy or more (V30), 40 Gy or more (V40), or 50 Gy or more (V50); mean lung dose (MLD); normal tissue complication probability (NTCP); and total dose. Fisher exact test was performed to compare clinical parameters between patients who developed severe RP and those who did not. Univariate and multivariate logistic regression analyses were performed to evaluate data for association between dose-volumetric parameters and severe RP. Pearson chi(2) test was used to assess data for correlations among dose-volumetric parameters. P < or = .05 was considered to indicate statistically significant difference. RESULTS: Of 76 patients, 30 (39%) did not develop RP; 23 (30%) developed RP of grade 1; 11 (14%), grade 2; 11 (14%), grade 3; and 1 (1%), grade 4. None had grade 5 RP. Age (< 60 vs > or =60), sex, Karnofsky performance status (< 70 vs > or =70), forced expiratory volume in 1 second, presence of weight loss, preexisting lung disease, history of thoracic surgery, and history of chemotherapy did not significantly differ between patients who developed severe RP and those who did not. In univariate analyses, MLD, V20, V30, V40, V50, and NTCP were associated with severe RP (P < .05). In multivariate analysis, MLD was the only variable associated with severe RP. CONCLUSION: MLD is a useful indicator of risk for development of severe RP after 3D conformal radiation therapy in patients with lung cancer.     

327例广泛期小细胞肺癌综合治疗的疗效分析

目的比较广泛期小细胞肺癌（ES-SCLC）化疗后加或不加胸部放疗的疗效,为ES-SCLC患者的综合治疗提供依据。方法回顾性分析2007年至2012年接受化疗±胸部放疗的327例初治ES-SCLC患者资料。其中,130例（39.8%）患者进行了胸部放疗（化放疗组）,197例（60.2%）接受单纯化疗（单纯化疗组）。化疗方案以EP（依托泊苷+顺铂）、CE（卡铂+依托泊苷）方案为主,胸部放疗采用调强放射治疗,放疗剂量为32~67 Gy。采用Kaplan-Meier法计算生存率,Log Rank法进行单因素预后分析,Cox回归模型进行多因素预后分析。结果全组随访率为95.1%。化疗后达完全缓解（CR）、部分缓解（PR）、稳定（SD）者分别占2.5%、76.1%和21.4%。全组中位生存时间为13.7个月,中位无进展生存时间（PFS）为9.3个月。化放疗组的生存时间和PFS均显著提高,中位生存时间为20.0个月,中位PFS为10.8个月,而单纯化疗组分别为11.4个月和7.7个月。化放疗组的2年、3年、5年总生存率（OS）分别为42.5%、27.8%、18.8%,而单纯化疗组分别为11.6%、6.6%、3.5%（χ2=50.730,P < 0.001）。亚组分析结果显示,按初诊脑转移状态和化疗疗效（CR+PR、SD）分层,胸部放疗均能显著提高OS,但不能延长初诊有脑转移的患者的PFS。胸部放疗能显著降低化放疗组的局部区域复发率至19.2%,而单纯化疗组为75.6%（χ2=100.080,P < 0.001）。结论对于化疗后无进展的ES-SCLC,胸部放疗可提高局部控制率,延长患者的总生存时间和PFS。     

Effect of induction chemotherapy on estimated risk of radiation pneumonitis in bulky non–small cell lung cancer

Patients with bulky non–small cell lung cancer (NSCLC) may be at a high risk for radiation pneumonitis (RP) if treated with up-front concurrent chemoradiation. There is limited information about the effect of induction chemotherapy on the volume of normal lung subsequently irradiated. This study aims to estimate the reduction in risk of RP in patients with NSCLC after receiving induction chemotherapy. Between 2004 and 2009, 25 patients with Stage IV NSCLC were treated with chemotherapy alone (no surgery or radiation therapy [RT]) and had computed tomography (CT) scans before and after 2 cycles of chemotherapy. Simulated RT plans were created for the prechemotherapy and postchemotherapy scans so as to deliver 60 Gy to the thoracic disease in patients who had either a >20% volumetric increase or decrease in gross tumor volume (GTV) from chemotherapy. The prechemotherapy and postchemotherapy scans were analyzed to compare the percentage of lung volume receiving≥20 Gy (V20), mean lung dose (MLD), and normal tissue complication probability (NTCP). Eight patients (32%) had a GTV reduction >20%, 2 (8%) had GTV increase >20%, and 15 (60%) had stable GTV. In the 8 responders, there was an absolute median GTV decrease of 88.1 cc (7.3 to 351.6 cc) or a 48% (20% to 62%) relative reduction in tumor burden. One had >20% tumor progression during chemotherapy, yet had an improvement in dosimetric parameters postchemotherapy. Among these 9 patients, the median decrease in V20, MLD, and NTCP was 2.6% (p<0.01), 2.1 Gy (p<0.01), and 5.6% (p<0.01), respectively. Less than one-third of patients with NSCLC obtain >20% volumetric tumor reduction from chemotherapy alone. Even with that amount of volumetric reduction, the 5% reduced risk of RP was only modest and did not convert previously ineligible patients to safely receive definitive thoracic RT.     

Correlation of dosimetric parameters obtained with the analytical anisotropic algorithm and toxicity of chest chemoradiation in lung carcinoma

The purpose of this study was to analyze and revisit toxicity related to chest chemoradiotherapy and to correlate these side effects with dosimetric parameters obtained using analytical anisotropic algorithm (AAA) in locally unresectable advanced lung cancer. We retrospectively analyzed data from 47 lung cancer patients between 2005 and 2008. All received conformal 3D radiotherapy using high-energy linear accelerator plus concomitant chemotherapy. All treatment planning data were transferred into Eclipse 8.05 (Varian Medical Systems, Palo Alto, CA) and dosimetric calculations were performed using AAA. Thirty-three patients (70.2%) developed acute pneumopathy after radiotherapy (grades 1 and 2). One patient (2.1%) presented with grade 3 pneumopathy. Thirty-one (66%) presented with grades 1–2 lung fibrosis, and 1 patient presented with grade 3 lung fibrosis. Thirty-four patients (72.3%) developed grade 1–2 acute oesophagic toxicity. Four patients (8.5%) presented with grades 3 and 4 dysphagia, necessitating prolonged parenteral nutrition. Median prescribed dose was 64 Gy (range 50–74) with conventional fractionation (2 Gy per fraction). Dose–volume constraints were respected with a median V20 of 23.5% (maximum 34%) and a median V30 of 17% (maximum 25%). The median dose delivered to healthy contralateral lung was 13.1 Gy (maximum 18.1 Gy). At univariate analysis, larger planning target volume and V20 were significantly associated with the probability of grade ≥2 radiation-induced pneumopathy (p = 0.022 and p = 0.017, respectively). No relation between oesophagic toxicity and clinical/dosimetric parameters could be established. Using AAA, the present results confirm the predictive value of the V20 for lung toxicity as already demonstrated with the conventional pencil beam convolution approach.     

Helical tomotherapy for radiotherapy in esophageal cancer: a preferred plan with better conformal target coverage and more homogeneous dose distribution.

We compare different radiotherapy techniques-helical tomotherapy (tomotherapy), step-and-shoot IMRT (IMRT), and 3-dimensional conformal radiotherapy (3DCRT)-for patients with mid-distal esophageal carcinoma on the basis of dosimetric analysis. Six patients with locally advanced mid-distal esophageal carcinoma were treated with neoadjuvant chemoradiation followed by surgery. Radiotherapy included 50 Gy to gross planning target volume (PTV) and 45 Gy to elective PTV in 25 fractions. Tomotherapy, IMRT, and 3DCRT plans were generated. Dose-volume histograms (DVHs), homogeneity index (HI), volumes of lung receiving more than 10, 15, or 20 Gy (V(10), V(15), V(20)), and volumes of heart receiving more than 30 or 45 Gy (V(30), V(45)) were determined. Statistical analysis was performed by paired t-tests. By isodose distributions and DVHs, tomotherapy plans showed sharper dose gradients, more conformal coverage, and better HI for both gross and elective PTVs compared with IMRT or 3DCRT plans. Mean V(20) of lung was significantly reduced in tomotherapy plans. However, tomotherapy and IMRT plans resulted in larger V(10) of lung compared to 3DCRT plans. The heart was significantly spared in tomotherapy and IMRT plans compared to 3DCRT plans in terms of V(30) and V(45). We conclude that tomotherapy plans are superior in terms of target conformity, dose homogeneity, and V(20) of lung.     

Comparison of clinical, tumour-related and dosimetric factors in grade 0-1, grade 2 and grade 3 radiation pneumonitis after stereotactic body radiotherapy for lung tumours

Objective

The aim of this study was to investigate significant clinical, tumour-related and dosimetric factors among patients with grade 0–1, grade 2 and grade 3 radiation pneumonitis (RP) after stereotactic body radiotherapy (SBRT) for lung tumours.

Methods

Patients (n=128) with a total of 133 lung tumours treated with SBRT of 50 Gy in 5 fractions were analysed. RP was graded according to the Common Terminology Criteria for Adverse Events v.3.0. Significant factors were identified by univariate and multivariate analyses. Threshold dose–volume histograms (DVHs) were constructed to identify the incidence of RP.

Results

The median follow-up period was 12 months (range, 6–45 months). In univariate analyses, gender, operability, forced expiratory volume in 1 s (FEV1), internal target volume, lung volumes treated with doses >5–30 Gy (V5–30) and mean lung dose were significant factors differentiating between grade 0–1 and grade 2 RP, and V15–30 were significant factors differentiating between grade 2 and grade 3. However, no factors were significant between grade 0–1 and grade 3 RP. Multivariate analysis showed that female gender, high FEV1 and high V15 were significant factors differentiating between grade 0–1 and grade 2 RP. Threshold DVH curves were created based on ≤5% and ≤15% risk of grade 2 RP among patients with grade 0–2 RP.

Conclusions

Grade 0–2 RP was dose–volume dependent, and female gender and high FEV1 were significant predictive clinical factors for grade 2 RP among patients with grade 0–2 RP. However, incidences of V15–30 in grade 3 RP were significantly lower than those in grade 2 RP, and no significant clinical or tumour-related factors were found. Further studies are needed to identify the mechanism underlying the development of grade 3 RP after SBRT for lung tumours.Previously, we investigated the clinical and dosimetric factors that correlate with severe radiation pneumonitis (RP) in patients with lung tumours treated with stereotactic body radiotherapy (SBRT) [1]. We found that, among a variety of factors, only a short latent period was a significant correlate of severe RP.Other reports [2-6] have also analysed the clinical and dosimetric factors correlated with RP after SBRT. Various dosimetric factors were reported to significantly correlate with RP after SBRT, which included the mean dose in the ipsilateral lung, V7 and V10 by Kyas et al [2], normal tissue complication probability (NTCP) by Ricardi et al [3], lung volumes treated with doses higher than 2.5–50 Gy (V2.5–50) by Guckenberger et al [4], mean lung dose by Barriger et al [5] and contralateral V5 by Ong et al [6].We found a discrepancy in the significant clinical and dosimetric factors between the results of these five studies on low-grade RP [2-6] and our study on severe RP [1]. We speculated that the mechanism underlying the development of grade ≥3 RP might be different from that of grade 2 RP. Additionally, the treatment of grade ≥3 RP was much more critical than that of grade 2 RP. Most patients with grade ≥3 RP needed to be admitted to hospital and steroids or oxygen therapy were administered. By contrast, patients with grade 2 RP were simply followed up carefully without administration of medication as outpatients.In the present study, to ascertain this discrepancy, we analysed the clinical and dosimetric factors that correlated with RP after SBRT among patients with grade 0–1, grade 2 and grade 3 RP in the same sample of patients as that included in our previous study [1].     

非小细胞肺癌适形放射治疗中急性放射性食管炎影响因素的研究

目的 探讨接受三维适形放疗(3D-CRT)的非小细胞肺癌(NSCLC)患者发生≥2级急性放射性食管炎(ARE)的影响因素。方法 回顾102例接受3D-CRT的NSCLC患者的临床资料及三维计划资料,采用RTOG分级标准,评价患者自放疗开始3个月内≥2级的ARE。分析临床因素和三维计划的剂量体积参数。结果 发生2级ARE19例,3级15例,未出现更严重的ARE。非同步化疗组多因素回归分析显示,食管V55(OR=1.170,P<0.05)为≥2级ARE发生的惟一影响因素,食管V55的ROC曲线下面积为0.870(95%CI: 0.782~0.957,P＜0.05),界值为16.0。同步化疗组多因素回归分析显示,食管V₃₅(OR=1.125,P<0.05)和同步化疗方案(OR=39.740,P<0.05)是≥2级ARE发生的影响因素,食管V₃₅的ROC曲线下面积为0.782(95%CI: 0.636~0.927,P<0.05),界值为23.75。长春瑞滨+顺铂(NP)同步化疗方案的≥2级ARE发生率明显低于其他方案(33.3% ∶66.7%)。结论 非同步化疗患者,食管V55是≥2级ARE的影响因素。同步化疗患者,食管V₃₅和同步化疗方案是≥2级ARE的影响因素。同步NP方案≥2级ARE发生率较低。     

Radiation therapy in small cell lung cancer: a national Italian survey

Introduction

Radiation therapy plays an important role in the management of SCLC both in curative and palliative setting, however, conflicting data from clinical trials incite debate over the appropriate use of radiation therapy regarding prophylactic cranial irradiation (PCI) and/or thoracic consolidative in extensive-stage SCLC (ES-SCLC). This survey is conducted to evaluate the current pattern of care among Italian radiation oncologists.

Methods

In June 2016, all Italian radiation oncologists were invited to a web-based survey. The survey contained 34 questions regarding the role of RT in SCLC. Questions pertaining the role of RT in the clinical management of both limited-stage (LS) and ES-SCLC were included.

Results

We received 48 responses from Italian radiation oncologists. More than half of respondents had been practicing for more than 10 years after completing residency training and 55% are subspecialists in lung cancer. Preferred management of LS-SCLC favored primary concurrent chemoradiotherapy (89%), even if the 36.9% usually delivered RT during or after the cycle 3 of chemotherapy, due to organizational issues. The most common dose and fractionation schedule in this setting was 60 Gy in 30 once-daily fractions. Furthermore, almost all respondents recommended PCI in patients with LS-SCLC. For ES-SCLC scenario, chemotherapy was defined the standard treatment by all respondents. PCI was recommended in ES-SCLC patients with thoracic complete remission (63% of respondents), with thoracic partial response (45%) and with thoracic stable disease (17%) after first-line chemotherapy. Lastly, the thoracic consolidative RT was recommended by 51% of respondents in patients with ES-SCLC in good response after first-line chemotherapy and a great variability was shown in clinical target volume definition, doses and fractionation schedules.

Conclusions

Our analysis showed a high adherence to current guidelines among the respondents in regard to chemoradiation approach in LS-SCLC patients and to PCI indications and doses. The great variability in radiation therapy doses and volumes in the thoracic consolidative radiotherapy in ES-SCLC is concerning. Future clinical trials are needed to standardize these treatment approaches to improve treatment outcomes among patients with ES-SCLC.

     

胸段食管癌患者三种放疗计划心脏和肺的剂量学比较

目的 比较胸中下段食管癌3种放疗技术心脏和肺的剂量分布。方法 搜集2015年1月至2016年2月在浙江省肿瘤医院接受治疗的15例胸中下段食管鳞癌患者资料。患者均接受胸部放射治疗,每位患者共制作3套放疗计划。调强放疗（IMRT）和容积旋转调强放疗（VMAT）在RayStation 4.0v系统制作,螺旋断层放疗（TOMO）在TomoH^TM Version 2.0.5系统制作。处方剂量60 Gy/30次。比较计划体积（PTV）、心脏、心脏亚单位以及肺剂量参数。结果 PTV、心脏和肺的平均体积为（399±355）、（671±274）和（3 907±1 717） cm³。与IMRT和VMAT相比,TOMO可以降低PTV、心脏、左心房及肺的最大剂量（H=10.889、7.433、12.080、11.401,P<0.05）。3种放疗技术的适形指数和均匀性指数差异无统计学意义（P>0.05）。结论 相较于IMRT和VMAT,TOMO可以降低PTV、心脏、左心房和肺的最大剂量,但均匀性及适形性差异无统计学意义。放疗过程中心脏与肺存在相互影响,TOMO技术可能带来的临床优势尚待进一步研究证实。     

Predictive factors for radiation pneumonitis in oesophageal cancer patients treated with chemoradiotherapy without prophylactic nodal irradiation

Objective

The objective of this study was to identify clinical and dosimetric factors for the development of radiation pneumonitis (RP) among patients with oesophageal cancer treated with three-dimensional radiotherapy without prophylactic nodal irradiation.

Methods

125 patients with oesophageal cancer had undergone dose–volume histogram (DVH) metrics and received chemoradiotherapy (CRT). Several clinical and dosimetric factors with regard to the lung were evaluated as predictive factors for the development of symptomatic RP.

Results

26 patients (20.8%) developed symptomatic RP classified as greater than or equal to Grade 2. By univariate analysis, body weight loss, tumour length, Stage IV, response to treatment and all DVH parameters proved to be significant factors for the development of RP (p<0.05). By multivariate analysis, Stage IV and all dosimetric factors were independent predictive factors for the development of symptomatic RP (p<0.05). Recursive partitioning analysis indicated that V10 values of 24.8% or more and Stage IV were associated with higher development of RP (odds ratio 6.53).

Conclusions

Our study demonstrated that severe RP was also developed in patients treated with the minimal radiation field. Stage IV and the dosimetric factors were identified as independent predictive factors for symptomatic RP in oesophageal cancer patients treated with CRT without prophylactic nodal irradiation.Definitive chemoradiotherapy (CRT) has been established as a curative option for patients with carcinoma of the oesophagus, and its clinical efficacy has expanded [1-4]. Because thoracic irradiation can cause late development of adverse events that involve the heart, lung and oesophagus, including death, radiation therapy management has become an important clinical issue, especially for patients with prolonged survival and follow-up [5-9]. Efforts to reduce adverse events have become increasingly important.Radiation pneumonitis (RP) is a major adverse event after thoracic irradiation, which occasionally results in death. In several studies, predictive factors for RP, including clinical factors and dosimetric parameters, have been reported for patients with lung cancer receiving definitive radiotherapy (RT) [10-14]. However, in oesophageal cancer, few reports are available on predictive factors for RP [15,16]. To our knowledge, the predictive factors for the development of RP have not been evaluated in detail for oesophageal cancer patients treated with minimal radiation field.The objective of the present study was to determine the predictive values of clinical and dosimetric factors for the development of symptomatic RP in oesophageal cancer patients treated with three-dimensional (3D) RT without prophylactic nodal irradiation.