初治鼻咽癌调强放疗的初步结果

目的分析调强放疗（IMRT）在初治鼻咽癌应用的初步结果.方法76例经病理证实的初治鼻咽癌患者接受了全程IMRT.根据1992年福州分期标准,Ⅰ期2例,Ⅱ期20例,Ⅲ期29例,Ⅳ期25例.采用多叶光栅的静态调强技术实施IMRT,采用的逆向治疗计划系统分别为TMS、CMS和Pinnacle.各靶区处方剂量均以其PTV定义给予,鼻咽肿瘤（GTV）和颈部淋巴结（GTV-LN）处方剂量为68～76Gy,鼻咽区域及上颈部临床靶区（CTV1）处方剂量为58～66Gy.下颈部锁骨上区域（CTV2）37例采用IMRT技术,处方剂量为50～60Gy,39例采用常规技术单前切线野照射.晶体、脑干、脊髓、视神经和视交叉的最高限量（99%体积低于此剂量）分别为8、54、40、54、54 Gy.7例合并同时化疗,4例IMRT后鼻咽局部予以立体定向放疗加量.采用Kaplan-Meier法计算生存率,RTOG标准评价急性副反应.结果中位随访期为10个月,全组死亡3例,分别死于鼻咽肿瘤未控大出血、肝转移和治疗相关并发症.1、2年总生存率分别为92%、92%;鼻咽和颈部1、2年局部控制率均为95%,4例出现了远处转移;1、2年无瘤生存率分别为95%、86%.急性反应以1、2级为主,其中唾液腺为99%,咽部和黏膜分别为88%和72%.GTV、GTV-LN、CTV1、CTV2的平均剂量均值分别为74.3、74.1、67.2、60.2Gy,平均低于95%处方剂量的靶区体积分别为0.58%、0.31%、0.67%、0.59%.左、右腮腺的中位剂量分别为33.9、34.0 Gy,晶体、脑干、脊髓、视神经、交叉最高剂量平均值分别为7.2、53.4、41.6、53.4、55.6 Gy.结论调强放疗技术能对初治鼻咽癌的各靶区达到很好的剂量分布,达到较高局部控制率,并降低了周围危及器官剂量和急性治疗反应,远期结果需进一步观察.     

初治鼻咽癌调强放疗布野及联合化疗的临床研究

[目的]研究鼻咽癌调强放射治疗(IMRT)的投照方式、近期临床疗效,以及单纯放疗和放、化疗结合的耐受性。[方法]2003年12月￣2005年12月157例初治鼻咽癌患者鼻咽和全颈及锁骨上全程实施前7野IMRT。鼻咽大体肿瘤体积(GTV1)、颈部大体肿瘤体积(GTV2)、临床靶体积1(CTV1)和临床靶体积2(CTV2)处方剂量分别为70Gy、66Gy、60Gy、50Gy,共32分次。88例患者行联合化疗。采用Kaplan-Meier法进行生存分析,RTOG标准评价急性反应和晚期损伤。[结果]治疗计划结果显示,靶区内GTV1、GTV2、CTV1和CTV2的平均剂量分别为70.5Gy、67.0Gy、60.1Gy和51.2Gy。中位随访时间16个月,1、2年局部区域无进展和无远处转移生存率及总生存率分别为97.4%、94.9%和93.6%、89.4%及96.4%、92.7%。放化综合治疗组的口咽、黏膜反应及血液系统毒性明显高于单纯放疗组。患者近期毒副反应均可以耐受,口干症状随着治疗后时间的延长逐渐减轻。[结论]IMRT使靶体积照射剂量提高,而周围器官受照剂量降低,对初治鼻咽癌可获得理想的局部区域控制,放化综合治疗对控制远处转移有一定价值。     

43例鼻咽癌的调强适形放射治疗体会

目的介绍调强适形放射(IMRT)治疗鼻咽癌的效果。方法对43例初治或复发鼻咽癌患者给予IMRT,将照射靶体积划分为鼻咽大体肿瘤体积(GTVnx)、颈部大体肿瘤体积(GTVnd)、临床靶体积1(CTV1)、临床靶体积2(CTV2)。处方剂量GTVnx68Gy~74Gy,GTVnd60Gy~66Gy,CTV160Gy,CTV254Gy;共30次。34例接受放化综合治疗,9例接受单纯放疗。结果GTVnx、GTVnd、CTV1、CTV2的平均剂量分别为72.40Gy、67.83Gy、60.25Gy和64.85Gy。中位随访期9个月,局部无进展生存率100%;1例放疗后4月出现肝和肺转移。结论IMRT技术对初治或复发鼻咽癌病例均可获得理想的剂量分布,正常组织得到很好的保护,毒副反应可以耐受,临床疗效令人满意。     

419例鼻咽癌患者调强放疗疗效和影响

目的 报道初治鼻咽癌调强放疗(IMRT)的长期随访结果并分析影响预后的因素.方法 419例初治鼻咽癌接受全程IMRT.UICC/AJCC2002分期Ⅰ、Ⅱ、Ⅲ和Ⅳ期分别为28、113、202和76例.182例单纯放疗,237例放化疗.放疗处方剂量:鼻咽大体肿瘤靶区66～70 Gy分25～30次,颈部淋巴结大体肿瘤靶区60～64 Gy分25～30次,临床靶区155～62 Gy分25～30次,临床靶区242～54 Gy分25～30次.结果 随访6～94个月,随访满5年患者166例.局部复发21例,区域复发13例,远处转移57例.5年局部控制率、区域控制率和无远处转移率分别为92.7%、95.8%和85.5%.5年无瘤生存率(DFS)、疾病特异生存率(DSS)和总生存率分别为76.3%、84.4%和83.3%.单因素分析显示T早期、疗前原发肿瘤体积≤20 cm~3、N早期、疗前颈淋巴结体积≤5 cm~3患者5年DFS和DSS优于各自对应项[84.1%:67.6%(χ~2=12.16,P:0.000)和92.1%:75.1%(χ~2=14.86,P=0.000);89.1%:62.9%(χ~2=14.13,P=0.000)和96.2%:72.1%,(χ~2=38.76,P=0.000);81.1%:64.5%(χ~2=15.49,P=0.000)和87.8%:76.1%(χ~2=10.89,P=0.001);83.3%:68.8%(χ~2=14.13,P=0.000)和90.0%:78.1%(χ~2=10.71,P=0.001)].多因素分析显示疗前原发肿瘤体积、N分期是DFS和DSS的独立预后因素(χ~2=26.81,P=0.000,χ~2=4.92,P=0.026和χ~2=28.47,P=0.000,χ~2=9.50,P=0.002).全组未观察到4级急性和晚期副反应;随访满3年以上的243例患者中,3级晚期毒副反应发生率仅为2.8%.结论 IMRT±化疗提高了初治鼻咽癌的长期疗效,尤其提高了局部和区域控制率.远处转移已成为治疗失败的最主要原因.疗前原发肿瘤体积和N分期是影响生存的主要因素.IMRT±化疗的急性副反应可耐受,晚期副反应轻微.     

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。     

128例初治鼻咽癌调强适形放疗临床分析

目的分析调强适形放疗(intensity modulated radiation therapy,IMRT) 治疗初治鼻咽癌的临床疗效。方法鼻咽癌IMRT 初治患者128例,按1992年福州分期标准,Ⅰ期2例,Ⅱ期19例,Ⅲ期58例,Ⅳa期49例。鼻咽大体肿瘤体积（GTVnx）处方剂量为(70~74)Gy分30次,颈部淋巴结（GTVnd）处方剂量为(68~70)Gy分30次,临床靶体积1（CTV1）(60~64)Gy分30次,临床靶体积2（CTV2）(50~54)Gy分30次。采用Kaplan-Meier法进行生存分析和局部控制率计算,Log-rank检验组间差异。结果中位随访时间12月(6~24月),1、2 年总生存率分别为100%、96.9%,1、2 年无远处转移生存率分别为92.2%、88.3%,1、2 年局部控制率分别为96.1%和93.8%。N分期是影响有无远处转移生存率的最重要预后因素( P =0.04)。最严重的急性不良反应是放射性黏膜炎,Ⅰ~Ⅳ级分别为38.8%、48.4%、7.8%、0。晚期不良反应主要表现为口干,Ⅰ级67.2%, Ⅱ级19.5%。结论鼻咽癌IMRT 靶区剂量高,周围正常组织受量小,不良反应轻,是一种治疗鼻咽癌的有效方法。治疗失败最主要的原因是远处转移,其发生率与颈淋巴结转密切相关。     

81例局部晚期鼻咽癌放疗的临床研究

目的观察3种不同治疗方案对局部晚期鼻咽癌的临床疗效、急性反应和晚期损伤。方法初治鼻咽癌81例,其中Ⅲ期50例,ⅣA期31例。单纯放疗组（RT）30例,常规放疗加化疗组（RT＋CT）33例,调强放疗加化疗组18例（IMRT＋CT）。常规放疗鼻咽部剂量70～76 Gy,肿大淋巴结60～65 Gy,颈部预防剂量50 Gy;调强放疗设鼻咽大体肿瘤为GTV（nx）、颈部阳性淋巴结GTV（nd）、高危临床靶体积CTV1和低危临床靶体积CTV2。处方剂量分别为GTV（nx） 70．6～76．6 Gy分31～33次、GTV（nd） 61．6～70．6 Gy分28～33次、CTV1 60 Gy分28次、CTV2 53．2 Gy分28次,化疗方案包括诱导、同期与辅助。生存率用Kaplan-Meier法计算,Logrank检验,RTOG或EORTC标准评价急性反应和晚期损伤。结果中位随访时间21．5个月,全组2和3年局部区域无进展、无远处转移生存率、总生存率分别为90%、85%、86%和83%、83%、83%;RT组分别为63%、82%、65%和52%、76%、60%;RT ＋CT组分别为76%、83%、77%和73%、83%、60%;IMRT＋CT组分别为100%、94%、100%和89%、94%、100%。RT组与RT＋CT组生存差异无统计学意义（X^2=0．53,P=0．473）,RT组与IMRT＋CT组生存差异有统计学意义（X^2=7．42,P=0．007）,RT＋CT组与IMRT＋CT组生存比较差异有统计学意义（X^2=5．06,P=0．028）。全组多数患者仅表现为1～2级急性反应和0～1级晚期损伤,RT组1例出现放射性脑病。放疗后1年中重度口干发生率RT组和RT＋CT组总计92%,而IMRT＋CT组仅表现为轻度口干。结论IMRT加化疗对局部晚期鼻咽癌患者可获得理想的局部区域控制和总生存率;IMRT可明显减轻放疗引发的口干。     

初治鼻咽癌调强适形放疗近期临床观察

目的研究调强放射治疗(IMRT)对初治鼻咽癌的疗效以及对正常组织的保护和毒性反应。方法对24例鼻咽癌初治患者鼻咽和全颈及锁骨上全程实施IMRT,肿瘤靶区授予处方剂量68~70Gy。对于Ⅲ和Ⅳ期患者,在IMRT同时,结合患者淋巴结转移及一般情况给予PDD+5-Fu±THP-ADM方案化疗1~2周期。结果治疗计划结果显示,覆盖鼻咽GTV1D95的平均剂量为70.48Gy,GTV1V95的平均体积为98.46%;靶区内GTV1、GTV2、CTV1和CTV2的平均剂量分别为70.48Gy、66.98Gy、60.10Gy和51.18Gy。本组有2例、16例、5例和1例患者分别出现0、1、2和3级的皮肤急性放射性反应;有4例、6例、13例和1例患者分别出现1、2、3和4级的口腔粘膜急性放射性反应;其中1例合并联合化疗患者因严重口腔粘膜炎中断放疗1周。其他合并化疗患者在化疗后均出现不同程度的骨髓抑制,经对症处理均未影响正常放射治疗。本组患者中位随访期13个月。无1例出现局部复发或远处转移。结论IMRT在初治早期或晚期鼻咽癌病例均可获得理想的剂量分布,正常组织得到很好的保护,毒副反应可以耐受,临床疗效令人满意。     

初治鼻咽癌调强放疗的前瞻性多中心临床研究

目的 观察调强放疗(IMRT)初治鼻咽癌的临床疗效及不良反应,并分析影响预后的因素。方法 2006—2008年,6个治疗中心共 300例经病理活检确诊为鼻咽癌的初治患者接受全程IMRT。UICC/AJCC 2002分期Ⅰ、Ⅱ、Ⅲ、Ⅳ_a+b期分别为6、45、141、108例。放疗处方剂量鼻咽原发灶计划把体积为 70~74 Gy,颈部转移淋巴结计划把体积为 68~70 Gy,计划靶体积 -1为 60~64 Gy,计划靶体积 -2为 50~54 Gy,均分30次6周完成。Ⅲ~Ⅳ_a+b期患者接受了以铂类为基础化疗。Cox法多因素预后分析。结果 随访率为99.7%。4年局部控制率、区域控制率、无远处转移率、无瘤生存率及总生存率分别为94.0%、95.5%、87.4%、80.8%及86.1%。急性1、2、3级放射性黏膜炎分别占18.0%、48.7%、33.3%,晚期 0、1、2级口干分别占12.0%、 75.7%、12.3%。18、15、42例出现局部﹑颈部淋巴结复发、远处转移。多因素分析显示N分期影响总生存率(χ²=5.17,P=0.023)、无远处转移率(χ²=6.91,P=0.009)、无瘤生存率(χ²=8.15,P=0.004)。结论 IMRT可提高初治鼻咽癌患者临床疗效,不良反应可耐受,治疗失败最主要原因为远处转移,N分期是影响预后的主要因素。     

复发鼻咽癌调强放疗的剂量学探讨

目的:分析和评价复发鼻咽癌调强放疗(IMRT)的剂量学特点.方法:30例局部、区域复发的鼻咽癌患者使用IMRT的再程放疗,其中7例同时伴有颈淋巴结转移.根据1992年福州分期标准进行再分期,Ⅰ、Ⅱ、Ⅲ、Ⅳ期分别为7、7、4、12例. 鼻咽大体肿瘤体积(GTV)处方剂量为58.80-78.76Gy,分次剂量2.0-2.92Gy.结果:治疗计划GTV的中位体积为37.46cm3(14.30-227.52 cm3),覆盖鼻咽GTVD95的平均剂量为62.56Gy,GTVV95的平均体积为98.69%;靶区内GTV、CTV1和CTV2的平均剂量分别为65.82Gy、54.02Gy和50.20Gy;GTV的平均分割剂量为2.28Gy(2.0-2.92Gy).结论:IMRT能较好覆盖肿瘤靶区而降低邻近敏感器官剂量.     

１１６例鼻咽癌一体化照射野调强放疗的疗效分析

目的　探讨初诊时无远处转移的鼻咽癌患者应用一体化照射野调强放疗的远期疗效、安全性及预后相关因素。方法　收集２００５年２月至２００８年１２月共１１６例初诊时无转移鼻咽癌患者,根据福州分期：Ⅰ期４例,Ⅱ期２２例,Ⅲ期４５例,ⅣＡ期４５例。所有患者均接受鼻咽和全颈部一体化照射野调强放疗,具体剂量为：ＧＴＶｎｘ６１.３２～７５Ｇｙ,ＧＴＶｎｄ６５～８０Ｇｙ,中位剂量均为７０Ｇｙ;ＣＴＶ１５６～６０Ｇｙ,ＣＴＶ２５０～５２Ｇｙ。２１例单纯放疗,９５例合并化疗,采用以铂类药物为基础的化疗方案。结果　随访率１００％,中位随访期２８个月（６～６０个月）。３例局部复发,３例颈淋巴结复发,１６例远处转移。１、２、３、４年总生存率及无疾病生存率分别为６％ 、９２％ 、９２％、８４％及９１％、８５％、８０％、８０％。１２例死亡患者中６例死于鼻咽癌远处转移,其余６例死于其他疾病。预后因素分析,临床分期、Ｔ分期与３年无疾病生存率、３年无转移生存率明显相关（Ｐ＜０.０５）。随访满２年的６５例患者中,６例出现３级以上口干（９.２％）,４例出现放射性脑病（３.４％）。全组未发现后组颅神经损伤及张口困难病例。结论　采用一体化照射野调强放疗技术治疗初诊时无转移鼻咽癌远期疗效较好,副反应发生率低,临床分期、Ｔ分期是其预后的相关因素。     

初治鼻咽癌调强适形放疗的疗效分析

目的 探讨根治性调强适形放疗（IMRT）治疗初治鼻咽癌的临床疗效及毒副反应。方法 74例鼻咽癌患者均接受全程IMRT照射,给予鼻咽大体肿瘤体积（GTVnx）处方剂量69.9Gy／30f,颈部转移淋巴结（GTVnd）69.9Gy／30f,临床靶体积1（CTV1）60Gy／30f,临床靶体积2（CTV2）54Gy／30f。按照RTOG/EORTC标准评价急性反应和晚期放射损伤;采用Kaplan-Meier法进行生存分析。结果 中位随访时间为39个月（13～80个月）。全组1、2、3、5年生存率分别为97.3％、93.8％、88.2％和77.2％,无远处转移生存率分别为93.2％、91.1％、91.1％和84.1％,局部区域控制率分别为98.6％、91.0％、86.8％和80.6％。不同临床分期和T分期患者的生存率差异均无统计学意义（P＞0.05）,而不同N分期患者的生存率差异有统计学意义（P=0.02）。在治疗失败的12例患者中,局部和区域失败分别占治疗失败病例的50.0％和16.7％,远处转移占58.3％。74例患者中3例出现3级口干,1例出现放射性颞叶损伤,4例出现3级张口困难,全组未发现颅神经损伤病例。结论 采用GTV照射剂量69.9Gy/30f IMRT治疗初诊时无远处转移的鼻咽癌远期疗效较好,毒副反应少,N分期是其预后的影响因素。     

Intensity-modulated radiotherapy in the treatment of nasopharyngeal carcinoma: an update of the UCSF experience

PURPOSE: To update our experience with intensity-modulated radiotherapy (IMRT) in the treatment of nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: Between April 1995 and October 2000, 67 patients underwent IMRT for NPC at the University of California-San Francisco (UCSF). There were 20 females and 47 males, with a mean age of 49 (range 17-82). The disease was Stage I in 8 (12%), Stage II in 12 (18%), Stage III in 22 (33%), and Stage IV in 25 (37%). IMRT was delivered using three different techniques: 1) manually cut partial transmission blocks, 2) computer-controlled auto-sequencing segmental multileaf collimator (SMLC), and 3) sequential tomotherapy using a dynamic multivane intensity modulating collimator (MIMiC). Fifty patients received concomitant cisplatinum and adjuvant cisplatinum and 5-FU chemotherapy according to the Intergroup 0099 trial. Twenty-six patients had fractionated high-dose-rate intracavitary brachytherapy boost and 1 patient had gamma knife radiosurgery boost after external beam radiotherapy.The prescribed dose was 65-70 Gy to the gross tumor volume (GTV) and positive neck nodes, 60 Gy to the clinical target volume (CTV), 50-60 Gy to the clinically negative neck, and 5-7 Gy in 2 fractions for the intracavitary brachytherapy boost. Acute and late normal tissue effects were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. The local progression-free, local-regional progression-free, distant metastasis-free rates, and the overall survival were calculated using the Kaplan-Meier method. RESULTS: With a median follow-up of 31 months (range 7 to 72 months), there has been one local recurrence at the primary site. One patient failed in the neck. Seventeen patients developed distant metastases; 5 of these patients have died. The 4-year estimates of local progression-free, local-regional progression-free, and distant metastases-free rates were 97%, 98%, and 66% respectively. The 4-year estimate of overall survival was 88%. The worst acute toxicity documented was as follows: Grade 1 or 2 in 51 patients, Grade 3 in 15 patients, and Grade 4 in 1 patient. The worst late toxicity was Grade 1 in 20 patients, Grade 2 in 15 patients, Grade 3 in 7 patients, and Grade 4 in 1 patient. At 3 months after IMRT, 64% of the patients had Grade 2, 28% had Grade 1, and 8% had Grade 0 xerostomia. Xerostomia decreased with time. At 24 months, only one of the 41 evaluable patients had Grade 2, 32% had Grade 1, and 66% had Grade 0 or no xerostomia. Analysis of the dose-volume histograms (DVHs) showed that the average maximum, mean, and minimum dose delivered were 79.3 Gy, 74.5 Gy, and 49.4 Gy to the GTV, and 78.9 Gy, 68.7 Gy, and 36.8 Gy to the CTV. An average of only 3% of the GTV and 3% of the CTV received less than 95% of the prescribed dose. CONCLUSION: Excellent local-regional control for NPC was achieved with IMRT. IMRT provided excellent tumor target coverage and allowed the delivery of a high dose to the target with significant sparing of the salivary glands and other nearby critical normal tissues.     

鼻咽癌小靶区调强放疗及化疗的远期疗效分析

目的 分析鼻咽癌(NPC)缩小临床靶区调强放疗(IMRT)的长期疗效,为小靶区IMRT技术在NPC中应用提供依据。方法 2003-2007年接受IMRT的鼻咽癌患者413例,中位年龄45岁,男311例、女102例。按第6版AJCC分期标准Ⅰ期3例、Ⅱ期66例、Ⅲ期235例、Ⅳ_a期78例、Ⅳ_b期31例。336例患者接受了以铂类为基础的化疗。结果 随访率100%,5年总生存率、局部控制率、无区域复发生存率、无远处转移生存率和无瘤生存率分别为80%、93%、96%、81%和75%。多因素分析提示T分期、N分期、年龄是影响总生存的预后因素(P=0.001、0.001、0.002),T分期、N分期是无远处转移生存的预后因素(P=0.000、0.001)。进展期鼻咽癌患者中诱导化疗组5年总生存有高于无诱导化疗组趋势(78%∶68%,P=0.053),辅助化疗者5年无远处转移生存率低于无辅助化疗者(65%∶83%,P=0.003)。结论 鼻咽癌小靶区IMRT技术安全可靠,远期疗效理想。     

Treatment of nasopharyngeal carcinoma with intensity-modulated radiotherapy: the Hong Kong experience

PURPOSE: To evaluate the efficacy of using intensity-modulated radiotherapy (IMRT) in the primary treatment of nasopharyngeal carcinoma (NPC), including the role of dose escalation above 66 Gy level. METHODS AND MATERIALS: Between July 2000 and September 2002, 63 newly diagnosed NPC patients were treated with IMRT. The disease was Stage I in 9 (14%), Stage II in 18 (29%), Stage III in 22 (35%), and Stage IV in 14 (22%). The prescribed dose was 66 Gy to the gross tumor volume (GTV) and positive neck nodes, 60 Gy to the planning target volume (PTV), and 54-60 Gy to the clinically negative neck. All 20 (100%) patients with T1-2a tumors received intracavitary brachytherapy (ICB) boost, and 15/42 (36%) patients with T2b-T4 tumors received conformal boost (8 Gy/4 fractions). Nineteen patients with advanced stage disease also received either neoadjuvant or concurrent chemotherapy. Acute and late normal tissue effects were graded according to the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Local relapse-free survival (LRFS), nodal relapse-free survival (NRFS), distant metastasis-free survival (DMFS), and overall survival (OS) were estimated using the Kaplan-Meier method. RESULTS: With a median follow-up of 29 months (range 8-45 months), 4 patients developed local in-field failure, 1 patient developed regional relapse, and 13 patients developed distant metastases. All 4 patients with local failure had either T3 or T4 disease before primary treatment and did not have ICB or conformal boost. The 3-year actuarial LRFS, NRFS, DMFS, and OS were 92%, 98%, 79%, and 90%, respectively. Multivariate analysis showed that dose escalation above 66 Gy was significantly associated with better PFS and DMFS, whereas GTV size was a significant adverse factor for OS. The worst acute mucositis was Grade 1 or 2 in 36 (59%), and Grade 3 in 25 (41%) patients. Acute dysphagia requiring tube feeding occurred in 5 (8%) patients. The proportion of patients with Grade 2-3 xerostomia was 57% at 3 months, and 23% at 2 years after IMRT. Within the subset of patients with a mean parotid dose of <31 Gy, the proportions with Grade 2-3 xerostomia were 30% and 17% at 3 months and 2 years, respectively. CONCLUSION: Our experience of using IMRT in the primary treatment of NPC showed a very high rate of locoregional control and favorable toxicity profile. Furthermore, we found that dose escalation above 66 Gy of IMRT-based therapy was a significant determinant of progression-free survival and distant metastasis-free survival for advanced T-stage tumors. Distant metastases represent the predominant mode of treatment failure.     

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.     

Update report of nasopharyngeal carcinoma treated with reduced-volume intensity-modulated radiation therapy and hypothesis of the optimal margin

Background and purpose

To establish the minimally required margins in different directions measured from GTV in the definitive treatment of nasopharyngeal carcinoma (NPC) using IMRT based on the 5-year results.

Methods and materials

Between November 2003 and May 2007, 414 patients with non-metastatic NPC were treated with IMRT according to our institutional protocol. Treatment outcomes at 5 years were analyzed. Distances from GTV-T to CTV2 (i.e., CTV 59.4 Gy) in 6 directions (anterior, posterior, superior, inferior, and bilateral) were measured and analyzed.

Results

The 5-year estimated overall survival (OS), disease free survival (DFS), local control (LC) were 80%, 77% and 95%, respectively. For the margins measured from GTV-T to CTV2, margins used with T4 disease were significantly and uniformly smaller than the whole group in all the 6 directions (P = 0.000, 0.000, 0.000, 0.000 and 0.046, respectively). However, no increase of local recurrence was associated to this limited margins used.

Conclusions

Our 5-years’ experience showed a very high LC rate. The strategy we used for CTV delineation was safe and reliable. Determined CTV through GTV expansion to a minimally required margin, using GTV + margin (used in our T4 patients) + the whole nasopharyngeal mucosa, especially for the patients with early T disease, might be feasible.