胸段食管癌术后预防照射三维适形放疗与常规放疗剂量学比较

目的：比较胸段食管癌术后预防照射三维适形放疗与常规放疗时的剂量分布特点以指导临床应用。方法：采用统一体位自身对照的方法,以三维治疗计划中体积剂量分布图（DVH）和等剂量曲线为评价标准,观察10例胸段食管癌术后预防照射患者分别在三维适形放疗和常规放疗56Gy时,靶区和正常组织的剂量分布情况。结果：靶区剂量95%PTV三维适形放疗组56Gy高于常规放疗组35.6Gy（P〈0.05）。达到56Gy的PTV体积三维适形放疗组为95%,高于常规放疗组51.5%（P〈0.05）。心脏V40、V50三维适形放疗组为26.5%、5.9%,低于常规放疗组47.7%、30.4%（P〈0.05）。双肺V20三维适形放疗组为23.8%,高于常规放疗组7.8%（P〈0.05）。脊髓最大照射剂量三维适形放疗组和常规放疗组分别为43.5Gy和44.5Gy（P〉0.05）。残胃V40、V50及最大剂量两组无显著差别（P〉0.05）。结论：在胸段食管癌术后预防照射中,三维适形放疗比常规放疗在保证靶区剂量上有明显优势,并使心脏损伤风险显著降低。在脊髓和残胃的剂量分布无明显差异。对双肺V20则提高较明显,临床应予以重视。     

非小细胞肺癌放射治疗不同模式的剂量学分析

目的分析常规放射治疗计划、三维适形放射治疗(3DCRT)计划和调强适形放射治疗(IMRT)计划治疗非小细胞肺癌(NSCLC)的疗效,评估3DCRT和IMRT与常规治疗的优越性。方法对经病理证实的50例中晚期NSCLC(Ⅲ～Ⅳ期)患者进行回顾性分析,计划靶区处方剂量66Gy,利用治疗计划系统(TPS)对每例患者分别设计常规、3DCRT和IMRT三种放疗计划,通过剂量体积直方图,比较三种计划对肿瘤靶区和正常组织器官的剂量分布。结果 (1)靶区适行度:处方剂量为66Gy时,三维适形放射治疗和调强适形放射治疗达此剂量的计划靶区(PTV)体积和95%PTV体积下的照射剂量均高于常规治疗,同时,调强适形放射治疗均高于三维适形放射治疗。(2)除全肺V20的IMRT检测外,3DCRT和IMRT治疗的肺受剂量均比常规治疗高。在全肺V5和全肺V10检测中,3DCRT比IMRT剂量低,其余检测中3DCRT比IMRT剂量高。(3)三种计划脊髓最大受照剂量均<45Gy。脊髓,食管及心脏受照剂量3DCRT均较常规放疗低,并且差异均有统计学意义(P<0.05)。结论 (1)3DCRT和IMRT较常规放射治疗明显提高了靶区的照射剂量和靶区的准确性,从而在相同处方剂量情况下提高了治疗肿瘤的控制率。(2)3DCRT和IMRT与常规放疗比较,对肺的保护性存在一定的局限性。(3)3DCRT和IMRT在一定程度上可降低正常组织受照剂量和并发症的发生概率,减少正常组织的放射损伤。(4)IMRT在靶区剂量分布上明显优于常规放射治疗和3DCRT,同时能在一定程度上更好的保护正常组织。     

食管癌常规放疗与三维适形放疗比较及4种不同设野技术的剂量学研究

目的:比较食管癌常规三野照射(2DRT)和三维适形放疗(3DCRT)两种不同的治疗方式中,以及三维适形照射4种不同设野方法的计划中靶区剂量及正常组织受量。方法:选取10例在我院治疗的食管癌患者的定位CT,由主治医师画出各自靶区,然后设计GTV和PTV。分别按常规三野照射,三维适形照射的4种不同的布野计划分别进行剂量计算。比较下列参数:①靶区剂量选择<95%剂量的体积百分比。②正常组织(选择心脏,左右肺门及双肺)在各计划中最高剂量(Dmax),最低剂量(Dmin),平均剂量(Dmean),90%、80%、30%及10%等剂量线包括的百分体积(V90、V80、V30及V10),脊髓仅选择最高受量。结果:①常规三野照射和适形放疗的比较:PTV各项指标于两者无显著性差异;脊髓有明显差异;左肺受量经t检验,Dmin、Dmean及V30值均有明显的差异。心脏、右肺门及右肺组织的各项参数均无显著性差别。②食管癌三维适形照射4种不同的布野的比较:PTV的剂量覆盖4种计划中无显著性差异。双肺受量t检验显示在V30及V10等指标上计划1、2较3和4有明显减少,提示在双肺低剂量区照射,受累体积方面前2种设野方法较优,类似的趋势也见于左侧肺门的受量上。心脏的受量、右肺门的剂量参数未见明确差异,剂量体积分布以旋转照射略差。结论:①食管癌三野常规照射与三野适形照射比较,三野适形放疗利于保护左肺组织和脊髓。②食管癌三维适形照射4种不同的布野靶区的正常组织受量不同,故布野选择应按患者的具体情况而定。     

食管癌常规放疗与三维适形放疗剂量学对比分析

  目的　比较中晚期食管癌三维适形放疗和常规放疗靶区剂量、正常组织受量、适形指数的差异。 方法 25例中晚期食管癌病例,应用放射治疗计划系统（TPS）分别设计2种照射技术,即三维适形放疗（A）和模拟常规放疗（B）,比较同一处方剂量 （66 Gy）靶区计划靶区体积（PTV）最大值 （Dmax）、最小值（Dmin）、平均值（Dmean）、适形指数（CI）;双肺V20、V30、Dmean、心脏V40、Dmean。 结果 PTV参数：A、B两组Dmax分别为62.90 Gy和68.49 Gy两者比较差异无统计学意义（t＝-0.11,P＞0.05）;A与B的Dmin 、Dmean、CI分别是56.70和27.36 Gy、63.65和60.88Gy,0.63和0.47,差异有统计学意义（均P＜0.05）。 危及器官：双肺V20、V30、Dmean A均高于B,差异有统计学意义（均P＜0.05）;心脏V40 、Dmean A低于B,差异有统计学意义（均P＜0.05）。结论　三维适形放疗相对常规放疗技术的靶区剂量分布更理想,对降低心脏受照射量有一定优势。肺的受照射量可能增加。     

食管癌三维适形放射治疗剂量学与放射性肺炎发生相互关系的研究

目的:通过食管癌常规放射治疗与三维适形放射治疗的技术对比研究,比较应用不同外照射技术时肿瘤靶区适形指数的差异,以及肺等正常组织受照射容积剂量与放射性肺炎并发症发生概率(NTCP)的关系.方法:应用三维治疗计划系统,对28例胸中段EPC分别设计三种照射技术(A:常规3野;B:适形3野;C:适形5野).比较在同一处方剂量(66 Gy)时肿瘤靶区的适形指数,全肺受照射剂量与肺的NTCP的差异.结果:A、B、C三种照射技术比较:1)靶区的适形指数从0.55±0.09提高至0.76±0.04 和 0.78±0.06.2)肺平均剂量从(16.54±2.35) Gy降低至(13.26±1.93) Gy和(3.38±1.61) Gy;肺的V20从(32.95±6.43)%降低至(23.01±6.25)%和(24.8±4.47)%;肺的V30从(17.25±4.96)% 降低至(12.18±3.66)%和(6.75±2.93)%.3)肺的 NTCP从(6.9±6.86)%降低至(1.14±1.11)%和(1±1.02)%.A、B和C三种照射技术比较差异均有统计学意义,P=0.000.结论:三维适形放射治疗技术的靶区剂量分布较理想,显著降低正常肺的照射体积和剂量,减少放射性肺炎NTCP.     

鼻咽癌调强放疗初步结果

目的:探讨鼻咽癌三维适形调强放射治疗(intensity-modulatedradiotherapy,IMRT)的初步疗效。方法:对91例经病理确诊的鼻咽低分化鳞癌患者进行调强放疗。处方剂量分别为GTV(鼻咽部和颈部淋巴结肿瘤靶区)66~70Gy,CTV1(临床靶区)60~62Gy,CTV2和CTVn(颈部淋巴结区域)54~56Gy。11例患者IMRT结束后有局部残留,1例采用IMRT追量照射10Gy/4次,其余给予鼻咽腔内后装追量照射9~15Gy/3~5次。分析疗效及放射治疗毒性。结果:中位随访时间12个月,1和2年生存率为97·1%和97·1%,局控率为97·1%和92·5%。急性放射反应多为Ⅰ度和Ⅱ度以口干和放射性口腔炎为主,分别占72·5%和58·2%。远期放射反应表现为不同程度的口干和听力下降,占患者的39·6%和17·6%。GTV、CTV1及CTV2的平均剂量分别为70·6、67·9和65·0Gy;5%体积的正常器官受照射剂量的平均值为:脑干41·4Gy,脊髓35·4Gy,左腮腺46·5Gy,右腮腺51·8Gy。结论:调强放疗能使得鼻咽癌各靶区得到很好的剂量分布,提高了初治鼻咽癌的局部控制率,明显减轻了急性放射反应。鼻咽癌IMRT处方剂量70Gy以上,CTV2预防照射的范围有待于进一步探讨。     

中心型NSCLC常规分割适形放疗与同期加量适形放疗剂量学比较

目的:比较局部晚期中心型非小细胞肺癌同期加量适形放疗和常规分割适形放疗计划的剂量分布。方法:收集经病理确诊的局部晚期非小细胞肺癌患者10例,每例患者均设计2个放疗计划。1)常规分割适形放疗计划(conven-tional fractionation radiotherapy,CFR):计划靶体积(planning target volume,PTV)照射剂量60Gy/30次;2)同期加量适形放疗计划(SIB-CR):PTV处方剂量50.4Gy/28次,临床靶体积(clinic target volume,CTV)处方剂量64.4Gy/28次。比较2种放疗计划的靶区剂量及肺、食管、脊髓和心脏等危及器官受量。结果:SIB-CR组较CFR组的大体肿瘤体积(gross tumor volume,GTV)D90、GTV D95分别增加了(1.777 0±0.200 5)Gy(P=0.005)、(1.757 0±0.135 9)Gy(P=0.008),差异均有统计学意义。SIB-CR组肺平均剂量、V5、V8、V10、V13、V20、V30、V40、V50和V55均小于CFR组,其中肺平均剂量、V8、V10、V13、V20、V30、V40和V50差异均有统计学意义,P<0.05。SIB-CR组脊髓最大剂量、平均剂量、V40及正常组织并发症概率(normal tissue complication probability,NTCP)均小于CFR组,其中脊髓最大剂量比较差异有统计学意义,P=0.022。SIB-CR组的食管最大剂量、平均剂量、食管V45、食管全周受照45Gy长度(LETT45)均小于CFR组,其中平均剂量、V45差异有统计学意义,P值分别为0.002和0.003。SIB-CR组的心脏最大剂量、平均剂量、V40均小于CFR组,差异无统计学意义,P>0.05。结论:SIB-CR较CFR能获得更高的肿瘤剂量,且能降低肺、脊髓、食管和心脏等危及器官受量,但还有待于进一步的临床研究。     

食管癌常规放疗与三维适形放疗剂量分布的比较

目的比较食管癌常规三野照射和三维适形放射治疗2种不同的治疗方法,不同设野方法的计划中靶区及正常组织的受量。方法应用三维治疗计划系统(TPS)在28例食管癌患者的CT虚拟图像上分别设计2种外照射计划(A:常规三野;B:三维适形三野),应用剂量体积直方图比较2种计划肺、心脏等正常组织受量及肺正常组织并发症发生概率(NTCP)的区别。根据肺的NTCP来估计放射性肺炎的发生概率。结果常规三野照射和适形放射治疗的比较:PTV各项指标无显著性差异,心脏受照的体积百分比(V40、V50)及左右肺及双肺受照的体积百分比(V20、V30)等有明显的差异(P=0)。结论食管癌三野常规照射与适形放射治疗比较:三野的适形放射治疗有利于保护心脏及正常肺组织,可降低放射性肺炎的发生概率。     

三维适形放疗与调强放疗在胸部上中段食管癌术后放疗中的剂量分布比较

目的:比较在胸部上中段食管癌术后预防性放射治疗中调强放射治疗（IMRT）与三维适形放射治疗(3D-CRT)剂量分布差异。方法:采用CMS治疗计划系统,对10例胸部上中段食管癌术后病理为T3/T4和/或淋巴结阳性患者分别设定3D-CRT 54Gy/27f照射和IMRT 54Gy/27f照射,比较两者相关靶区和危及器官的剂量体积直方图参数及靶区适形指数（CI）。结果:在相同靶区相同剂量模式下,10例患者在肺、脊髓、胃等组织器官受量近似一致的情况下,IMRT等剂量线的剂量分布（95%CTV、95%PTV和100%PTV）及靶区适形指数（CI）（0.93 vs 0.79）均优于3D-CRT。结论:相同靶区相同剂量模式下,胸部上中段食管癌术后预防性照射治疗时,调强放疗技术（IMRT）靶区剂量分布优于三维适形放疗（3D-CRT）。     

肺癌三维适形放疗计划设计的剂量学分析

 目的 比较肺癌常规二维放疗和三维适形放疗计划的剂量学特征。方法 采用美国RAHD三维放疗计划系统对20例肺癌术后患者分别进行常规二维及三维适形放疗计划设计，根据剂量-体积直方图等参数对两者剂量学特征进行评估分析。结果 与常规二维计划相比较，三维适形放疗计划的靶区适形度好，剂量分布均匀；全肺受照体积V20及脊髓最大剂量均明显低于二维计划。结论 肺癌患者采用三维适形放疗技术，可提高靶区剂量，进而有助于提高肿瘤局部控制率，同时能有效地保护靶区周围正常组织和器官。     

Clinical and dosimetric study of radiotherapy for glioblastoma: three-dimensional conformal radiotherapy versus intensity-modulated radiotherapy

Journal of Neuro-Oncology - We aimed to compare three-dimensional conformal radiotherapy (3D-CRT) with intensity-modulated radiotherapy (IMRT) for the treatment of glioblastoma. Retrospective study...     

Comparison of conventional radiotherapy and intensity-modulated radiotherapy for post-operative radiotherapy for primary extremity soft tissue sarcoma

Introduction

Doses in conventional radiotherapy for extremity soft tissue sarcoma (STS) potentially exceed normal tissue tolerances. This study compares 3D-conformal radiotherapy (3D-CRT) with intensity-modulated radiotherapy (IMRT) in optimising target volume coverage and minimising integral dose to organs-at-risk (OAR).

Methods and materials

Ten patients undergoing post-operative radiotherapy for extremity STS were assessed. PTV₁ was defined as tumour bed plus 5 cm superiorly/inferiorly and 3 cm circumferentially, PTV₂ was defined as 2 cm isotropically. OAR were defined as whole femur, neurovascular bundle, tissue corridor and normal tissue outside PTV₁. For each patient 2-phase 3D-CRT was compared to 2/3 field (2/3f) and 4/5 field (4/5f) IMRT with simultaneous integrated boost (SIB). The primary planning objective was to minimise femur and skin corridor dose. Volumetric analysis and conformity and heterogeneity indices were used for plan comparison.

Results

A planning protocol containing dose/volume constraints for target and OAR was defined. 4/5f IMRT showed greatest conformity and homogeneity. IMRT resulted in significantly lower femur V45 using 2/3f (p = 0.01) and 4/5f (p = 0.0009) than 3D-CRT. 4/5f IMRT resulted in significantly lower normal tissue V55 (p = 0.004) and maximum dose (p = 0.04) than 3D-CRT.

Conclusions

A reproducible set of planning guidelines and dose-volume constraints for 3D-CRT and IMRT planning for extremity sarcomas was devised. 4/5f IMRT with SIB resulted in better target coverage and significantly decreased OAR dose. Further evaluation of this technique within a clinical trial is recommended to demonstrate that the technical benefit of the more complex technique translates into patient-derived benefit by reducing late toxicity.     

宫颈癌根治性放疗中三维适形调强放疗技术的应用

目的:探讨三维适形调强技术在宫颈癌放射治疗中的应用.方法:应用PubMed检索系统,以"宫颈癌、调强放疗"为关键词,检索2000-01-2009-10相关宫颈癌调强治疗文献.进一步筛选有关调强放疗在宫颈癌根治性放疗中降低胃肠道及骨髓毒性、靶区的勾画原则及调强放疗在后程推量中的应用的文献有26篇.结果:盆腔、盆腔延伸野适形调强放疗可以降低小肠、骨髓、直肠、膀胱和肾脏在高剂量区的受照射体积,降低严重急性毒性的发生率.膀胱、直肠充盈状态及肿瘤体积的变化,导致子宫体、子宫颈位移.每周进行CT或MR定位扫描并进行靶区勾画及计划设计可以减少危及器官在计划靶体积(PTV)中的受照射体积.在宫颈癌根治性放疗中建议使用调强技术与腔内技术结合进行后程推量治疗.结论:三维适形调强放射治疗在宫颈癌根治性治疗中具有重要的意义,临床治疗结果仍在观察中.     

Comparison of intensity-modulated radiotherapy, adaptive radiotherapy, proton radiotherapy, and adaptive proton radiotherapy for treatment of locally advanced head and neck cancer

Background and purpose

Various radiotherapy planning methods for locally advanced squamous cell carcinoma of the head and neck (SCCHN) have been proposed to decrease normal tissue toxicity. We compare IMRT, adaptive IMRT, proton therapy (IMPT), and adaptive IMPT for SCCHN.

Materials and methods

Initial and re-simulation CT images from 10 consecutive patients with SCCHN were used to quantify dosimetric differences between photon and proton therapy. Contouring was performed on both CTs, and plans (n = 40 plans) and dose-volume histograms were generated.

Results

The mean GTV volume decreased 53.4% with re-simulation. All plans provided comparable PTV coverage. Compared with IMRT, adaptive IMRT significantly reduced the maximum dose to the mandible (p = 0.020) and mean doses to the contralateral parotid gland (p = 0.049) and larynx (p = 0.049). Compared with IMRT and adaptive IMRT, IMPT significantly lowered the maximum doses to the spinal cord (p < 0.002 for both) and brainstem (p < 0.002 for both) and mean doses to the larynx (p < 0.002 for both) and ipsilateral (p = 0.004 IMRT, p = 0.050 adaptive) and contralateral (p < 0.002 IMRT, p = 0.010 adaptive) parotid glands. Adaptive IMPT significantly reduced doses to all critical structures compared with IMRT and adaptive IMRT and several critical structures compared with non-adaptive IMPT.

Conclusions

Although adaptive IMRT reduced dose to several normal structures compared with standard IMRT, non-adaptive proton therapy had a more favorable dosimetric profile than IMRT or adaptive IMRT and may obviate the need for adaptive planning. Protons allowed significant sparing of the spinal cord, parotid glands, larynx, and brainstem and should be considered for SCCHN to decrease normal tissue toxicity while still providing optimal tumor coverage.     

放疗技师独立模拟定位的可行性分析

目的:探讨放疗技师独立模拟定位的可行性和意义。方法:根据医师填写的模拟定位申请单,应用模拟定位机独立完成照射野设计,医师审核计划并确定治疗剂量和分割方式后实施治疗。结果:技师独立完成603例各种肿瘤患者的模拟定位,二次定位率5.3%(32/603)。结论:技师独立模拟定位具有可行性。     

Flash放疗

Flash放疗是利用超高剂量率超快辐射所产生的对正常组织有保护作用的Flash效应进行的放疗。由于其独特的放射生物学优势,Flash放疗正受到学术界和工业界越来越多的关注,成为了当前放疗领域的前沿热点。本文总结了目前已开展及计划开展Flash照射实验报道,对各类细胞和动物实验、实验条件及实验结果等进行了归纳;同时介绍了Flash效应可能的生物学机理和分析了Flash放疗面临的挑战,对潜在的临床应用进行了展望。     

Optimization of radiotherapy

Carcinoma of the nasal pharynx, Spinal cord, Optimization of therapy, Treatment characteristic (TC), Radiotherapeutic operating characteristic (ROC).     

Costs of radiotherapy

A systematic assessment of radiotherapy for cancer was conducted by The Swedish Council on Technology Assessment in Health Care (SBU) in 2001. The assessment included an overview of the capacity for radiotherapy in terms of infrastructure of cancer care and an estimation of the costs of radiotherapy in Sweden. A postal questionnaire distributed to all 16 centres of radiotherapy in Sweden showed the following results: In 2000 there were 57 accelerators with complementary equipment in operation, 24 of which had been installed 10 or more years ago earlier. The total cost of external radiation therapy was estimated at SEK 427 million in the year 2000, or approximately 5% of the estimated total cost of oncology care in Sweden. The total cost of brachytherapy was estimated at SEK 43 million or about one-tenth of that of external radiotherapy. The total cost of external radiotherapy has increased since the last inquiry (1991) by about 16% more than the general inflation in Sweden, but at the same time the volume of fractions has increased by about 37%. Thus, an increase in the efficiency of external radiotherapy, calculated per fraction, was achieved in the 1990s. At the department level, there was a clear correlation between cost of salaries and output of fractions of external radiotherapy, thus indicating the adaptation of manpower to the volume of patients. There was an even higher correlation between the number of accelerators and the volume of fractions of radiotherapy, which suggests the occurrence of certain economies of scale in Swedish external radiotherapy.     

非小细胞肺癌术后三维适形放疗与常规放疗的疗效比较

背景与目的：非小细胞肺癌术后三维适形放疗与常规放疗的疗效比较目前尚缺乏长期随访结果．本研究回顾性分析非小细胞肺癌（NSCLC）术后分别采用三维适形放疗和常规放疗的疗效及放疗反应，比较不同放疗技术对疗效及放疗反应的影响。方法：收集1990年12月-2002年8月美国M．D．安德森癌症研究中心收治的167例Ⅲ．期NSCLC患者的术后放疗资料进行回顾性分析。其中常规放疗组（CV组）90例．三维适形放疗组（CF组）77例。CV组放疗中位剂量为54．3Gy／27次．CF组放疗中位刹龟为53．9Gy／26次．均在5～6周内完成。结果：两组患者病例特征具有可比性。CV组和CF组中位随访时间分别为36个月和24个月，两组无瘤生存率、局部控制率及无远处转移生存率差异无显著性，但两组总生存率差异有显著性（P=0．014）。CF组在肺部纤维化、心脏损伤和血液系统放疔反应发生率显著性上要低于CV组，其余放疗反应差异基本尤最著性。两组死亡原因差异有显著性，CV组有8例患者死于与心脏损伤有关的并发症，而CF组没有。结论：Ⅲ、期NSCLC术后采用改进的三维适形放疗技术不仅可以取得与常规放疗类似的疗效，还可提高总生存率，同时降低了肺部纤维化、心脏损伤和血液系统反应发生率，三维适形放疗的治疗优势值得关注．