调强适形放射治疗剂量学验证体系的建立

模体内剂量实测为基础的验证是调强适形放射治疗计划的主要剂量验证方法.该文将胶片剂量仪和针点电离室作为主要测量工具,介绍了剂量测量系统的建立方法:并选择1例鼻咽癌患者,介绍模体内剂量实测为基础的调强适形放射治疗计划剂量验证方法.     

非小细胞肺癌调强放疗与螺旋断层放疗剂量学的比较研究

目的 比较螺旋断层放射治疗(Tomo Therapy治疗计划系统)和常规加速器静态调强放射治疗(Precise Plan治疗计划系统)非小细胞肺癌(NSCLC)患者的剂量分布特点及差异.方法 回顾性分析并设计Tomo Therapy和IMRT治疗计划,计划分别传输至Tomo Therapy治疗计划系统(Tomo组)和Precise Plan治疗计划系统(IMRT组),肿瘤靶区给予70 Gy/33 F照射剂量,临床靶区给予60 Gy/33F照射剂量,正常器官全肺<30%、脊髓<45 Gy、心脏<30%、食管<30%,根据剂量分布、剂量体积直方图(DVH)等指标,比较两组剂量分布特点.结果 Tomo组的GTV放射剂量参数HI(1.047±0.015)cGy、Dmax(7406.2±137.1)cGy,均显著低于IMRT组(P<0.05),Tomo组HI值更接近于1.两组CI、Dmini、Dmean比较差异不显著(P>0.05).Tomo组的PTV放射剂量参数Dmax(7306.4±151.4)cGy、Dmean(6603.8±143.7)cGy,均显著低于IMRT组(P<0.05),两组的CI、Dmini、HI比较差异不显著(P>0.05).Tomo组的患侧肺脏放射剂量参数Dmax、Dmini、Dmean值与IMRT组比较具有统计学意义(P<0.05).Tomo组的健侧肺脏放射剂量参数Dmax、Dmini、值与IMRT组比较具有统计学意义(P<0.05),Dmean值比较差异不显著(P>0.05).Tomo组的脊髓放射剂量参数Dmean、Dmini值与IMRT组比较具有统计学意义(P<0.05),Dmax值比较差异不显著(P>0.05).Tomo组的心脏放射剂量参数Dmax、Dmean、Dmini值与IMRT组比较差异均无统计学意义(P>0.05).Tomo组的食管放射剂量参数Dmi-ni值显著高于IMRT组,差异均有统计学意义(P<0.05),两组患者的Dmax、Dmean值差异不显著(P>0.05).结论 研究表明螺旋断层放射治疗肺癌较常规加速器静态调强放射治疗具有更好的放射均匀性,同时对邻近器官组织的放射性伤害更小.     

Cost-effectiveness of Intensity-modulated Radiotherapy in Oropharyngeal Cancer

AimsIntensity-modulated radiotherapy (IMRT) is an advanced radiation technique that is particularly suited to treating head and neck cancers because it can conform a high dose to the target volume while preserving the tissue function of neighbouring structures. The objective of this study was to compare the cost and effectiveness of IMRT with three-dimensional conformal radiotherapy (3DCRT) for the treatment of locally advanced oropharyngeal cancer.Materials and methodsWe developed a Markov model to estimate the incremental cost per quality-adjusted life-year (QALY) gained by IMRT from the perspective of the Ministry of Health. The costs of IMRT and 3DCRT were estimated through activity-based costing, incorporating input from radiation oncologists, physicists and radiation therapists. We obtained clinical effectiveness estimates from published studies and calculated the number needed to treat to avoid a case of severe long-term xerostomia using data from a randomised controlled trial.ResultsThe delivery of IMRT produced 0.48 more QALYs than 3DCRT at an additional cost of $2447 (QALY and costs discounted at 5% a year), yielding an incremental cost-effectiveness ratio of $5084 per QALY gained. The cost-effectiveness of IMRT was sensitive to the costs of radiotherapy and the effect of IMRT on health-related quality of life. The cost of IMRT will probably decrease with the addition of volumetric modulated arc therapy, an increasingly used technology, because volumetric modulated arc therapy reduces treatment time. We need to treat less than two patients with IMRT to avoid a case of severe, long-term xerostomia (dry mouth), and the incremental cost to avoid a case of severe, long-term xerostomia was $4532.ConclusionsIn the treatment of locally advanced oropharyngeal carcinoma, the IMRT strategy appears to be cost-effective when compared with 3DCRT.     

鼻咽癌调强放射治疗的剂量学特点

[目的]分析鼻咽癌调强放疗各个靶区和周围正常器官的剂量学特点.[方法]2004年7月至10月入院的10例初治鼻咽癌调强放疗病人,用前7野方案,每野的照射范围从颅底到锁骨上淋巴预防区.剂量处方是:GTV1为2.18Gy/次,32次,GTV2为2.03Gy/次,32次,CTV1为1.88Gy/次,32次,CTV2为1.80Gy/次,28次.研究GTV的最大、最小和平均剂量,CTV的最小剂量,脊髓、脑干和晶状体的最大剂量,腮腺的50%体积受照剂量.[结果]10例病人GTV1的最大、最小和平均剂量(均值)分别是72.01Gy、68.65Gy、70.48Gy,GTV2的最大、最小和平均剂量(均值)分别是68.66y、65.50Gy、66.98Gy,CTV1的最小剂量为60.10Gy,CTV2的最小剂量为51.18Gy,脊髓、脑干和晶体状的最大剂量分别为44.7Gy、51.7Gy和6.8Gy,高剂量侧和低剂量侧,腮腺的50%体积的受照剂量分别为44.39Gy和39.36Gy.[结论]调强放疗可以使各个靶区得到足够的、均匀的剂量分布,周围的正常组织受到比较好的保护,腮腺50%体积受照剂量控制在40Gy～45Gy,显示已有较好的保护作用.     

6MV与15MVX线在胸中段食管癌调强放疗计划的比较

目的探讨胸中段食管癌调强放疗的能量选择。方法对10例胸中段食管癌分别采用6 MV和15 MVX线设计调强放疗计划,比较2种计划靶区剂量分布及危及器官剂量体积受量。结果 2种计划靶区最大剂量、中位剂量、平均剂量、照射时间及适形度指数、均匀性指数比较均无明显差异;双肺V5、V10、V15、V25、V30、脊髓最大剂量、心脏V30、V40及中位剂量2种计划比较,差异无统计学意义。结论 6MV与15MV均可以满足胸中段食管癌调强放疗的要求,建议选择6MV设计放疗计划。     

局部晚期鼻咽癌调强放疗联合含奈达铂不同方案同期化疗的疗效分析

[目的]评价调强放疗联合含奈达铂方案化疗治疗局部晚期鼻咽癌的临床疗效及不良反应.[方法] 166例Ⅲ、Ⅳa期初治鼻咽癌患者接受调强放疗联合同期含奈达铂方案化疗.调强放疗采用鼻咽及全颈同步整合加量(SIB)技术,按两进程给予:鼻咽部剂量70Gy/32F,颈部淋巴结剂量66Gy/32F,颈部预防剂量高危区60Gy/32F、低危区50.4Gy/28F.放疗期间同步化疗2个周期,21d为1个周期.含奈达铂化疗方案分为3组:FP(5-氟尿嘧啶+奈达铂)58例;TP(紫杉醇+奈达铂)62例;TFP(紫杉醇+5-氟尿嘧啶+奈达铂)46例.分析比较3组患者的疗效和急性不良反应.[结果]166例患者全部按计划完成同期放化疗.中位随访43个月,FP组的4年总生存率、局部控制率、区域控制率及无远处转移生存率分别为81.5％、93.0％、98.2％、79.0％,TP组为81.7％、91.4％、96.8％、82.0％,TFP组为84.7％、90.8％、93.3％、81.9％.3组间比较总生存率(P=0.752)、局部控制率(P=0.961)、区域控制率(P=0.423)及无远处转移生存率(P=0.836)均无显著性差异.治疗相关不良反应主要为骨髓抑制、胃肠道反应、放射性口腔黏膜炎.3组患者Ⅲ～Ⅳ级急性不良反应发生率分别为17.2％vs 22.6％vs 41.3％,差异有显著性(P=0.016),TFP组较TP组及FP组发生率明显增加(P=0.037,P=0.007).多因素分析结果表明N分期是影响患者总生存率(P=-0.036)和无远处转移生存率(P=0.037)的独立预后因素.[结论]调强放疗联合同期含奈达铂方案化疗治疗局部晚期鼻咽癌,可获得较好肿瘤控制和生存率,患者顺应性好,反应可耐受.TFP三药方案较FP、TP两药方案急性不良反应的发生明显增加,临床疗效相近.N分期是影响预后的主要因素,远处转移是治疗失败的主要原因.     

鼻咽癌后程三维适形与传统放疗剂量对比分析

目的比较鼻咽癌后程三维适形(3-dimensionalconformalradiotherapy,3DCRT)和传统放疗(2-dimensionalradiotherapy,2DRT)在靶区和周边重要器官的不同剂量分布并探究3DCRT的潜在优势.方法比较和分析5例鼻咽癌7野后程3DCRT和其相应的2DRT在各靶区和重要器官的剂量体积直方图(dosevolumehistogram,DVH)的各项指标值.结果与2DRT相比,3DCRTPTV的Dmean从92.7%提高至96.1%;剂量不均匀度(DI)从84.1%降至59.3%;90%等剂量线适形指数(CI)从0.32提高到0.51;但两者PTV接受90%处方剂量的体积均小于90%;在颈动脉鞘区,3DCRT的Dmean提高了5%但Dmax达117.2%.3DCRT和2DRT相比,串行器官如视神经、脑干和颞叶的Dmax分别为:33.5%和104.3%,11.7%和26.4%,97.6%和103.2%;但在晶体、眼球和下颌骨则分别为:16.1%和2.8%,21.3%和8.7%,115.3%和104.2%.在并行器官的Dmean,颞颌关节:68.5%和93.3%;耳蜗:58.5%和69.0%;而腮腺则为59.8%和43.3%。结论与传统放疗相比,鼻咽癌后程3DCRT降低了视神经、脑干、颞叶、颞颌关节和耳蜗的剂量,但却增加了晶体、眼球、下颌骨和腮腺的剂量.3DCRT使靶区剂量的适形性分布有所改善,潜在可能使颈动脉鞘区受累的鼻咽癌患者受益.但靶区剂量覆盖仍显不足,通过调强放疗有望达到更理想的剂量分布.     

容积调强放疗在鼻咽癌中的应用

鼻咽癌调强放疗的优势已得到公认,本文综述鼻咽癌容积调强放疗和普通调强放疗由于单次照射时间的明显不同,其剂量学分布、生物学行为、临床价值的差异,了解容积调强放疗在鼻咽癌放疗中的作用。     

调强放疗对鼻咽癌患者甲状腺功能的影响

目的 探讨鼻咽癌患者调强放射治疗后早期甲状腺功能的变化情况,为甲状腺功能保护提供依据.方法 收集经病理证实、排除基础甲状腺疾病且接受IMRT治疗的鼻咽癌患者.分析对比放疗前后TT3和TT4水平.结果 全组患者治疗前、后TT3水平分别为1.83 IU/L、1.69 IU/L,治疗前、后TT4水平分别为124.66 IU/L、127.23 IU/L.其中150例(59.8％)治疗后TT3水平下降,变化具有统计学差异(P=0.001).N3患者放疗后血清TT3及TT4水平均明显降低(P值分别为0.043、0.032).结论 IMRT模式下,鼻咽癌患者放疗结束时甲状腺激素降低,N3患者尤为明显.N3患者可运用VMAT/Tomotherapy等技术降低甲状腺照射剂量,且应早期监测甲状腺激素水平,发现问题及早干预.     

适形调强放射治疗后鼻咽癌患者甲状腺功能减退的风险因素分析及控制

目的 分析适形调强放射治疗后鼻咽癌患者甲状腺功能减退的危险因素及其控制策略.方法 选取行放射治疗的鼻咽癌患者183例,根据是否发生甲状腺功能减退分为甲减组和非甲减组,采用单因素及多因素logistic回归分析筛选适形调强放射治疗后鼻咽癌患者甲状腺功能减退的独立危险因素,建立联合预测模型并分析其控制策略.结果 183例患...     

T2期鼻咽癌旋转调强与固定野动态调强计划的剂量学比较研究

目的：比较旋转调强（ intensity-modulated arc radiotherapy,IMAT）与固定野动态调强（ dynamic intensity-modulated radiation therapy,dIMRT）在T2期鼻咽癌放射治疗计划中的剂量学差异。方法：随机选取10例已经接受固定野动态调强放射治疗的T2期鼻咽癌病例,将这10例放疗计划改为旋转调强方式,重新进行计划优化,比较两种计划的等剂量分布、靶区和危机器官的剂量参数、机器跳数以及治疗时间等。结果：两种计划的靶区剂量分布D98、D95以及D2等参数均无统计学差异（P〉0．05）,IMAT计划的脑干Dmax和D1cc、脊髓Dmax、右腮腺Dmean、右颞颌关节Dmax以及左中耳Dmean和Dmax均明显小于dIMRT计划的受量（P〈0．05）;同时IMAT计划的左右晶体Dmax、左右视神经Dmax和视交叉Dmax均明显大于dIMRT计划的受量（P〈0．05）。 IMAT计划正常组织受照剂量为5Gy的总体积明显大于dIMRT计划（P〈0．05）,而受照剂量在20Gy和30Gy的总体积明显小于dIMRT计划（P〈0．05）。 IMAT比dIMRT计划的单次照射总机器跳数平均减少了47．0%,单次照射时间平均减少48．2%。结论：对于T2期鼻咽癌,两种计划的剂量分布均满足临床要求,在靶区剂量分布没有统计学差异的情况下,IMAT技术能显著降低机器跳数,大大缩短治疗时间。     

鼻咽癌调强放射治疗进展

文章从调强放射治疗的优势，以及鼻咽癌靶区的确定及勾画入手，分析总结调强放射治疗在鼻咽癌中的应用进展及其存在的问题与对策，并对其发展趋势影像介导的调强放射治疗作了展望。     

Neck Node Bolus Technique in the Treatment of Nasopharyngeal Carcinoma with Intensity-modulated Radiotherapy

Purpose: To study the effect of bolus versus no bolus in the coverage of the nodal tumour volume withintensity-modulated radiotherapy (IMRT) for the treatment of nasopharyngeal carcinoma (NPC). Methods andMaterials: This retrospective study used data from 5 consecutive patients with NPC who were treated with bolusfor large neck nodes using IMRT from November 2011-January 2012 in our institute. All these patients weretreated radically with IMRT according to our institution’s protocol. Re-planning with IMRT without bolus forthese patients with exactly the same target volumes were done for comparison. Comparison of the plans was doneby comparing the V70 of PTV70-N, V66.5 of PTV70-N, V65.1 of PTV70-N and the surface dose of the PTV70-N.Results: The mean size of the largest diameter of the enlarged lymph nodes for the 5 patients was 3.9 cm. Themean distance of the GTV-N to the skin surface was 0.6 cm. The mean V70 of PTV70-N for the 5 patients showedan absolute advantage of 10.8% (92.4% vs. 81.6%) for the plan with bolus while the V66.5 of PTV70-N had anadvantage of 8.1% (97.0% vs. 88.9%). The mean V65.1 also had an advantage of 7.1% (97.6% vs. 90.5%). Themean surface dose for the PTV70-N was also much higher at 61.1 Gy for the plans with bolus compared to only23.5 Gy for the plans without bolus. Conclusion: Neck node bolus technique should be strongly considered inthe treatment of NPC with enlarged lymph nodes treated with IMRT. It yields a superior dosimetry comparedt o non-bolus plans with acceptable skin toxicity.     

Target Volume Definition for Intensity-modulated Radiotherapy after Induction Chemotherapy and Patterns of Treatment Failure after Sequential Chemoradiotherapy in Locoregionally Advanced Oropharyngeal Squamous Cell Carcinoma

AimsTo validate our approach to target volume definition for intensity-modulated radiotherapy (IMRT) after induction chemotherapy and to analyse the pattern of treatment failure in patients with locoregionally advanced oropharyngeal squamous cell carcinoma (SCC) after sequential chemoradiotherapy (SCRT).Materials and methodsWe studied all patients with locoregionally advanced oropharyngeal SCC treated with SCRT, definitive IMRT and no prior surgery between December 2004 and February 2010. SCRT consisted of three cycles of induction chemotherapy followed by IMRT with concurrent weekly chemotherapy. Our approach to IMRT tumour volume definition after induction chemotherapy was similar to recommendations from published clinical practice guidelines. Volumetric expansion was used to create the high-dose clinical target volume with a margin of 10 mm. The high-dose planning target volume (PTV) was treated to 65 Gy, whereas the prophylactic-dose PTV received 54 Gy over 30 fractions using the simultaneous integrated boost technique. The location and extent of each treatment failure was recorded, reconstructed on the planning computed tomography images and analysed using the dose distribution of the IMRT plan.ResultsFifty-two patients were included. The median follow-up was 32.2 months (range 5.0–67.1 months). There were seven local failures, no regional recurrences and one with distant disease. None of the patients required post-treatment neck dissection. All local failures were in-field and occurred within the high-dose PTV. There were no marginal recurrences. Actuarial recurrence-free, disease-specific and overall survival rates at 3 years were 83.9, 85.9 and 79.7%, respectively.ConclusionsThe absence of marginal recurrences validated the approach to IMRT target volume definition after induction chemotherapy proposed by clinical practice guidelines and practised at our institution. It suggested a lack of benefit with the use of larger geometric margins and additional anatomical expansion for the high-dose clinical target volume. SCRT resulted in excellent regional and distant disease control in patients with locoregionally advanced oropharyngeal SCC.     

多西他赛联合奈达铂同步调强适形放疗治疗局部晚期鼻咽癌

目的探讨多西他赛联合奈达铂同步调强适形放疗(IMRT)治疗局部晚期鼻咽癌(NPC)的临床疗效和毒副反应。方法 64例经病理学确诊的初治局部晚期NPC患者随机均分为2组,观察组32例患者行多西他赛联合奈达铂化疗同步IMRT,对照组患者则行奈达铂联合5-氟尿嘧啶化疗同步IMRT。治疗后评价2组临床疗效和毒副反应。结果 2组患者鼻咽大体肿瘤靶区和颈部转移淋巴结体积缩小的百分率比较差异无统计学意义(P>0.05);2组患者NPC病灶和颈部转移淋巴结病灶完全缓解率比较差异均无统计学意义(P>0.05)。观察组Ⅲ、Ⅳ度中性粒细胞减少、恶心或食欲减退、呕吐、腹胀、口腔黏膜反应的发生率均明显低于对照组(P<0.05)。观察组患者1、2 a总生存率和无进展生存率分别为100.00%、96.88%和100.00%、93.75%,对照组分别为100.00%、93.75%和100.00%、90.63%,比较差异均无统计学意义(P>0.05)。结论多西他赛联合奈达铂同步IMRT治疗局部晚期NPC的安全有效,值得在临床上推广应用。     

口咽鳞癌的单纯放射治疗

本文报告了法国保尔拉马克戈罗德厄勒中心1970～1976年收治的215例口咽鳞癌病人的治疗结果,其中男性202例,女性13例,平均年龄60岁(24～84岁),全部病例均按UICC方法分类,经~(60)CO或直线加速器X线照射,肿瘤剂量为72～78Gy,全组随访时间均在5年以上,12例失访,3年、5年生存率分别为37.5％和29.9％。结果表明生存率与肿瘤大小、淋巴结受累程度、病理分类、肿瘤部位等因素有关。     

调强放疗对头颈部肿瘤患者甲状腺功能的影响

目的 探讨调强放疗对头颈部肿瘤患者甲状腺功能的影响.方法 40例头颈部恶性肿瘤(不包括甲状腺来源的恶性肿瘤),接受调强适形放射治疗,采用放射免疫法检测放疗前及放疗后3、6、12、18及24个月的T3、T4以及TSH水平.结果 40例头颈部非甲状腺癌的恶性肿瘤患者中,放疗后3、6、12、18及24个月T3、T4下降及TSH升高分别有1例(2.5％)、3例(7.5％)、5例(12.5％)、7例(17.5％)和10例(25％),其中2例(5％)伴有轻度的表情淡漠等临床症状,给予补充甲状腺素治疗后好转.结论 调强放射治疗可导致甲状腺功能不同程度的改变,且随着随访时间的延长,甲状腺功能损伤发生率呈增高趋势,应引起临床关注.