428 例鼻咽癌患者颈部及Ⅴ区后缘转移淋巴结位置分布规律研究*

目的:分析鼻咽癌患者颈部及Ⅴ区后缘淋巴结的转移规律,指导鼻咽癌颈部放疗靶区的勾画。方法:回顾性分析2013年2月至2016年4 月就诊于成都军区总医院428 例经病理确诊为鼻咽癌的患者,所有患者均行颅底至锁骨下缘的增强CT模拟扫描。淋巴结分区采用RTOG 等推荐的分区指南（2013版）,由两位医师共同阅片对颈部及Ⅴ区后缘的转移淋巴结进行分析,并选取1 例N 0 期的鼻咽癌患者作为标准,参照Ⅴ区后缘正常解剖结构位置及比例,将428 例患者中有Ⅴ区后缘转移淋巴结的中心点勾画于标准病例的定位CT图像上,采用SPSS19.0 软件分析Ⅴ区后缘淋巴结转移与其余各区淋巴结之间的相关性,并分析Ⅴ区后缘转移淋巴结的位置及特点。结果:428 例患者中381 例（89.0%）出现淋巴结转移,转移概率最高的前4 位淋巴结区依次为Ⅱb（75.2%）、Ⅶa（60.3%）、Ⅱa（59.6%）、Ⅲ（42.0%）;21例（4.9%）出现Ⅴ区后缘淋巴结转移,共统计Ⅴ区后缘转移淋巴结32枚,各枚淋巴结中心点在标准患者上距斜方肌前缘的垂直距离均值为16mm。相关性分析提示Ⅴ区后缘淋巴结转移与同侧Ⅴa 区相关（P = 0.001）。 结论:鼻咽癌颈部淋巴结按照从上到下,由近及远的顺序转移,跳跃性转移的发生率低;Ⅴ区后缘淋巴结转移与同侧Va区阳性相关;Va区淋巴结转移时,同侧V 区后界的勾画应适当后移至斜方肌前缘后25mm。      

基于CT图像的非小细胞肺癌锁骨上淋巴结转移规律及放疗靶区探讨

目的:探寻未手术及放疗的肺癌行根治性或预防性放疗锁骨上淋巴结靶区勾画的范围。方法:将锁骨上区域按主要解剖转移途径分区,回顾性分析肺癌在锁骨上淋巴结的转移分布特点,进一步精确肺癌在锁骨上淋巴结靶区勾画范围。结果:锁骨上淋巴结转移的肺癌病例中有双侧锁骨上淋巴结的占31%;锁骨上淋巴结转移在Ⅰ区出现的占22%,多数与其他区（如Ⅱ区及Ⅳ区）同时出现;锁骨上Ⅱ区淋巴结转移占绝大部分,为99%,与他区一同出现或单独出现。锁骨上Ⅲ区出现淋巴结转移的约3.9%,且全部合并有Ⅱ区淋巴结转移,多伴有大的肿瘤负荷,纵隔及锁骨上广泛的淋巴结转移。Ⅳ区出现淋巴结转移的占16%,均合并有Ⅰ区或Ⅱ区淋巴结转移。结论:Ⅰ区及Ⅱ区是肺癌锁骨上淋巴结转移的主要集中区,临床上考虑进行锁骨上预防性照射时建议包括Ⅰ、Ⅱ区;当Ⅱ区存在淋巴结转移时,结合患者耐受性,考虑Ⅳ区照射。     

磁共振成像RTOG分区在鼻咽癌淋巴结转移中的诊断价值

背景与目的：美国肿瘤放射治疗协会（Radiation Therapy Oneology Group,RTOG）等组织联合发表了对于头颈部肿瘤的淋巴结分区方法及N0期病例亚临床靶区勾画的推荐标准,但对于N＋的患者是否同样适用没有明确的定论。本研究旨在探讨RTOG分区对勾画鼻咽癌淋巴结转移颈部靶区的价值。方法：收集伴有淋巴结转移的初治鼻咽鳞癌患者254例,全部病例进行常规鼻咽部MRI平扫及增强检查,采用RTOG推荐的头颈部肿瘤淋巴结转移的分区方法进行淋巴结分区。结果iRTOG分区的标志在横断位MRI图像上均清晰可辨。254例患者中,107例（42．1％）出现淋巴结坏死,78例（30．7％）有包膜外侵犯,4例（1．6％）出现跳跃性转移。51例（20．1％）患者出现了RTOG分区以外的淋巴结侵犯,1Ib区上界以上区域有42例,斜方肌前缘以后的区域有6例受累,Ⅳ区的下界以下有23例。51例患者中,20例为两处出现了RTOG分区以外的淋巴结侵犯。本组未见单纯发生在RTOG分区以外的淋巴结转移病例。结论：MRI可以用来进行颈部淋巴结的RTOG分区;应用RTOG分区勾画鼻咽癌淋巴结转移的颈部靶区时,边界应适当放宽。     

乳腺癌术后放射治疗和食管癌根治性放射治疗在锁骨上淋巴结区域临床靶区勾画范围的差异

目的探讨乳腺癌术后放射治疗及食管癌根治性放射治疗在锁骨上区照射范围的差异。方法回顾性分析2003年5月至2013年4月间广东省中山市人民医院收治的127例食管癌患者及115例乳腺癌患者锁骨上淋巴结转移情况,测量CT轴位图像上转移淋巴结的相对位置。结果两组患者在淋巴结转移数目、高于环状软骨的转移数目和转移途径分区上的分布差异无统计学意义(P>0.05)。食管癌患者转移淋巴结中心至体中线的距离(转移距离)为(1.76±1.21)cm,范围0~5.20 cm,95%CI的上限为5.01 cm,乳腺癌患者转移淋巴结的转移距离、范围和95%CI上限依次为(1.49±0.98)cm、0~4.60 cm和4.39 cm,两者差异无统计学意义(P>0.05)。结论食管癌根治性放射治疗和乳腺癌术后放射治疗的锁骨上淋巴结区域CTV勾画范围近似,需包括所有解剖引流区,外界均以离体中线不超过6 cm为宜。     

512例鼻咽癌颈淋巴结转移规律的研究

背景与目的:合理定义鼻咽癌颈部靶区在临床上显得越来越重要,本研究旨在探讨鼻咽癌颈淋巴结转移的规律,以指导三维适形放射治疗颈部靶区的勾画.方法:收集2003年1月～2004年6月在中山大学肿瘤防治中心初治的鼻咽癌病例512例,所有病例均经病理证实、并行增强CT模拟扫描.淋巴结分区标准采用2003年RTOG推荐的颈部淋巴结分区标准.结果:512例病例中,328例(64.1%)诊断为有淋巴结转移.淋巴结阳性的病例中61.3%为单侧淋巴结转移,38.7%为双侧淋巴结转移.咽后淋巴结的发生率为64.1%,其中单侧占50.9%,双侧占49.1%.淋巴结阳性的病例中Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ和咽后区的转移率分别为3.0%、97.9%、46.0%、9.5%、13.7%、0%和74.4%.跳跃性转移率仅为4.6%～6.5%.25.3%的N1-3病例出现了推荐标准以外区域的侵犯.结论:鼻咽癌的颈部淋巴结转移是由上而下循序性的;跳跃性转移发生率低;咽后淋巴结为鼻咽癌转移的首站淋巴结.咽后、Ⅱ区和Ⅲ区最容易受累及;Ⅰa和Ⅵ区从未受累.有部分阳性淋巴结超出了RTOG推荐用于N0的颈部CTV范围.以上结果有助于鼻咽癌的三维适形放疗和调强放疗颈部靶区的勾画.     

鼻咽癌颈淋巴结Som分区和RTOG分区的比较

目的：根据鼻咽癌淋巴结转移的分布来比较颈淋巴结Som分区法和RTOG分区法的局限性。方法：259例鼻咽癌患者在治疗前均接受了CT横断面增强扫描,范围从颅底至锁骨,由头颈部肿瘤放疗医师和影像诊断医师共同阅片,分别根据颈淋巴结Som分区和RTOG分区准则来评价淋巴结转移的分布规律,并进一步比较两种分区方法的局限性。结果：259例患者中,218例存在淋巴结转移,按照Som分区,在各区的分布分别是ⅠA 0例、ⅠB 6例、ⅡA 136例、ⅡB 171例、Ⅲ 78例、Ⅳ 20例、Ⅴ60例、Ⅵ10例、Ⅶ0例、锁骨上5例和咽后102例,另有55例位于颈内动脉内侧和颅底下2cm至舌骨之间。按照RTOG分区分别是ⅠA 0例、ⅠB 6例、ⅡA 115例、ⅡB 192例、Ⅲ78例、Ⅳ20例、Ⅴ65例、 Ⅵ 0例和咽后157例。其中38例ⅡB淋巴结上缘超过第1颈椎下缘水平,2例位于耳前,不属于Som分区和RTOG分区的任何区域。结论：颈淋巴结Som分区对咽后淋巴结的范围描述不够确切,咽后淋巴结的下界延伸至舌骨水平更理想。RTOG分区对ⅡB上界规定不充分,ⅡB上界为第一颈椎上缘更理想。     

初诊同侧锁骨上淋巴结转移乳腺癌综合治疗疗效

目的 探讨应用新辅助化疗+手术+放疗治疗初诊为锁骨上淋巴结转移乳腺癌患者疗效。方法 回顾分析1999-2013年肿瘤医院收治的65例女性乳腺癌患者的病历资料。全部患者均经初诊病理结果确诊为乳腺癌,且经病理或影像学检查证实为锁骨上淋巴结转移、无远处转移及其他第二原发癌,完整接受术前化疗+手术+术后放疗方案。采用Kaplan-Meier法计算总生存(OS)、无进展生存(PFS)及锁骨上淋巴结复发(SCFR)率,Logrank法检验差异。结果 中位随访时间66个月(6~137个月)。65例患者中5例患者治疗后锁骨上淋巴结复发。全组患者5年SCFR、OS、PFS率分别为9%、72%、50%。术前化疗后锁骨上淋巴结完全缓解是影响OS因素,是否完全缓解患者5年OS率分别为81%和54%(P=0.035)。初诊锁骨上淋巴结大小 (短径≤1 cm、>1 cm)为5年SCFR(分别为0%、21%,P=0.037)和5年OS(分别为86%、56%,P=0.001)的高危因素。结论 对于初诊为锁骨上淋巴结转移的乳腺癌患者,完整接受术前化疗+手术+术后放疗方案治疗后的OS率较高,锁骨上区放疗可获得良好的肿瘤局部控制。     

乳腺癌术后调强放疗颈胸一体固定的摆位误差分析

目的:探讨使用颈胸一体架(膜)对乳腺癌术后放疗患者体位固定的效果。方法:前瞻性入组32例乳腺癌术后放疗患者,均使用颈胸一体架(膜)进行体位固定,采用调强放疗技术照射乳腺/胸壁和锁骨上下区,并在放疗中进行锥形束CT(CBCT)位置验证,分别配准乳腺/胸壁靶区和锁骨上下区靶区。对239次CBCT图像的摆位误差和上下靶区位置...     

食管鳞状细胞癌淋巴转移规律与放疗临床靶区勾画设计的相关性

目的探寻食管鳞状细胞癌的淋巴转移规律与放射治疗临床靶区域勾画设计相关性。方法将纵膈区域按主要解剖转移途径分区,分析食管鳞状细胞癌在纵膈淋巴结的转移规律及分布特点,进一步精确食管鳞状细胞癌在纵膈淋巴结靶区勾画范围。结果在纳入研究病例中,有纵膈淋巴结转移的食管鳞状细胞癌病例上下区纵膈淋巴结占31%。多数与其他区(如Ⅱ区及Ⅳ区)同时出现,纵膈淋巴结Ⅰ区出现占22%。纵膈Ⅱ区出现淋巴结有152例(99%),且可与其他区一同出现或单独出现。纵膈Ⅲ区出现淋巴结约3.9%,且全部合并有Ⅱ区淋巴结转移,多伴有纵隔及纵膈广泛的淋巴结转移。Ⅳ区均合并有Ⅰ区或Ⅱ区淋巴结,出现淋巴结转移占16%。结论推荐出现纵膈淋巴结转移者行上下区纵膈淋巴结区预防照射;Ⅰ区需包括;重点勾画Ⅱ区纵膈淋巴结区;不推荐在纵膈淋巴结区域预防性勾画时包Ⅲ区,但在Ⅱ区淋巴结肿瘤负荷较大时可个体化适当包;推荐在Ⅰ区或Ⅱ区较大肿瘤负荷时考虑扩展Ⅱ区范围至Ⅳ区。     

乳腺癌锁骨上淋巴引流区照射方式的探讨

目的:探讨乳腺癌术后锁骨上淋巴引流区简单合理的照射方法.方法:选择30例乳腺癌伴有腋窝淋巴结转移术后患者行CT模拟定位,并勾画出锁骨上淋巴引流区.测量锁骨上淋巴引流区的最大深度及体积,分析其与身体指数(BMI)的相关性.在DRR图像上分别模拟设计2个常规放疗计划.计划A:单-6 MV光子线;计划B:6 MV光子线与12 MeV电子线混合.根据勾画的锁骨上淋巴引流区制定计划C(6与15 MV光子线混合).采用2个指标评价各个计划90%等剂量线包绕靶区体积(V90)和105%刺量线的靶区体积(V105).结果:锁骨上淋巴引流区最大深度变化范围为2.9～5.0 cm,平均为3.9 cm,体积17.1～38.4 cm3,平均26.3 cm3.BMI与淋巴引流区最大深度密切相关,P=0.039;与体积无关,P=0.92.计划A的V90及V105分剔为92.1%及(21.2±8.6)%,计划B分别为93.0%及(3.5±3.3)%,计划C分别为99.4%及(3.3±2.6)%.结论:乳腺癌术后锁骨上淋巴引流区照射,不论是采用单光子线或光子线与电子线混合的常规照射方式均不能得到良好的靶区剂量分布.采用权重4:1的6与15MV光子线混合可以获得良好的剂量分布,尤其是对于肥胖惠者更有意义.中华肿瘤防治杂志,2009,16(1):69-71     

乳腺托架固定下全乳调强放疗摆位误差兆伏X线验证平片测定分析

目的 用兆伏(MV) X线平片测定乳腺托架固定下全乳放疗摆位误差,探讨自由呼吸状态下临床靶体积(CTV)外扩至计划靶体积(PTV)的边界。
方法 选取2010-2012年本科行保乳术后调强放疗的29例乳腺癌患者,其中17例行全乳照射,12例行全乳和锁骨上淋巴引流区照射。均采用乳腺托架体位固定,利用放疗计划系统数字重建图像与治疗期间拍摄正交MV验证平片比较,确定摆位误差。对接受锁骨上淋巴引流区照射与未照射的误差比较行成组t检验。
结果 全体患者共获得正交MV验证平片图像127套,平均每人(4.4±1.2)套。全组患者左右、上下、前后方向摆位误差分别为(0.9±3.1)、(0.7±3.0)、(1.2±2.1) mm,摆位误差的系统误差分别为3.1、3.0、2.1 mm,随机误差分别为2.7、3.3、3.5 mm;做与未做锁骨上淋巴引流区照射者的摆位误差无差异(t=0.02、0.20、0.20,P=0.98、0.85、0.85)。CTV至PTV边界左右、上下、前后方向分别为9.6、9.8、7.7 mm。
结论 用乳腺托架固定全乳调强放疗的CTV外放PTV在左右、上下、前后方向上应至少分别为9.6、9.8、7.7 mm。     

Risk of subclinical micrometastatic disease in the supraclavicular nodal bed according to the anatomic distribution in patients with advanced breast cancer

PURPOSE: To determine the anatomic distribution of gross supraclavicular nodes within the supraclavicular fossa using 2-deoxy-2-[F-18] fluoro-d-glucose (FDG) positron emission tomography/computed tomography (PET/CT) scans, and to evaluate likely coverage of specific regions of the supraclavicular fossa using standard radiation fields. METHODS AND MATERIALS: We identified 33 patients with advanced or metastatic breast cancer who had a PET/CT scan demonstrating hypermetabolic supraclavicular lymph nodes in 2005. The locations of the involved lymph nodes were mapped onto a single CT set of images of the supraclavicular fossa. These lymph nodes were also mapped onto the treatment-planning CT dataset of 4 patients treated in our institution (2 patients with biopsy-proven supraclavicular nodes and 2 patients with clinically negative supraclavicular nodes). RESULTS: We were able to determine the distribution of 52 supraclavicular lymph nodes in 32 patients. Of 32 patients, 28 (87%) had a history of metastatic disease, and 2 patients had isolated nodal recurrences. Five patients had supraclavicular nodes posterior to the vertebral body transverse process, and several lymph nodes were in close proximity to the medial field border, raising the possibility of geographic miss in these areas. CONCLUSIONS: In patients with locally advanced disease, increased coverage of the supraclavicular fossa medially and posteriorly may be warranted.     

食管癌术后放疗锁骨上区CTV范围的临床研究

探讨食管癌根治术后预防性放疗锁骨上区的照射范围。方法：回顾性分析食管癌根治术后锁骨上淋巴结的复发情况,测量CT轴位图像上复发淋巴结的相对位置,包括淋巴结中心至体中线的距离（复发距离）和淋巴结的上界。结果：共收集66例术后锁骨上区复发患者,复发淋巴结76枚。复发淋巴结的平均长短径是（2.05±1.02） cm×（1.55±0.73） cm。复发距离为1.77±1.19 cm（范围0～5.4 cm）,95%参考范围的上限为5.05 cm。除锁骨上复发淋巴结（环状软骨弓水平以下）之外,收集到5枚颈部复发淋巴结（位于环状软骨弓水平以上）。出现环状软骨弓水平以上复发的患者所占比例4.5%（3/67）。结论：食管癌术后预防性放疗锁骨上区的CTV不需要包括最外侧的颈横血管淋巴引流区,外界以离体中线不超过6cm为宜。仅照射环状软骨弓或环甲膜水平以下锁骨上区较合理。     

乳腺癌保乳术后全乳逆向IMRT对腋窝Ⅰ—Ⅲ站及前哨淋巴结剂量覆盖评估

目的 评估早期乳腺癌保乳术后全乳逆向IMRT对腋窝Ⅰ、Ⅱ、Ⅲ站及前哨淋巴结区域的剂量覆盖情况。方法 回顾分析2008—2012年间在复旦大学附属肿瘤医院接受保乳手术及前哨淋巴结活检术的40例乳腺癌患者临床资料。术后全乳逆向IMRT处方剂量为50 Gy分25次。按照RTOG标准及术中放置钛夹的位置勾画腋窝Ⅰ、Ⅱ、Ⅲ站及前哨淋巴结区域,并分析相应区域受量。结果 腋窝Ⅰ、Ⅱ、Ⅲ站淋巴结的平均剂量分别为(33.0±7.5)、(17.9±11.3)、(7.3±6.6) Gy,V₉₅分别为(29.9±17.7)%、(9.0±14.5)%、(0.1±0.3)%。所有前哨淋巴结均位于第Ⅰ站腋窝淋巴结区域,前哨淋巴结的平均剂量为(43.0±10.0) Gy,58%(19/33)的平均剂量>45 Gy。结论 采用逆向IMRT照射乳腺时,腋窝Ⅰ、Ⅱ、Ⅲ站淋巴结受量有限,对前哨淋巴结微转移且未清扫腋窝者应充分考虑这一因素。     

Three-field technique for breast treatment using a rotatable half-beam block

A new three-field technique for the radiation therapy of breast cancer has been developed. Two opposing tangential fields treat the breast, chest wall, and ipsilateral internal mammary lymph nodes. The third, an anterior field, treats the axilla and supraclavicular area. The objective of the technique is to make the posterior geometric edges of the tangential fields coplanar, and also to make their cephalad geometric edges and the caudad geometric edge of the supraclavicular field coplanar. To effect the matching of fields, the technique utilizes a rotatable half-beam shielding block. To simplify the simulation procedure, an exact mathematical solution is given for the required treatment set-up parameters.     

局部晚期和复发性乳腺癌患者区域淋巴结转移分布特点及靶区勾画意义

目的 通过对局部晚期和区域复发性乳腺癌患者区域淋巴结累及范围的分析,探讨常规区域淋巴结放疗技术对淋巴引流区照射的合理性,并为合理的靶区勾画原则提供临床证据.方法 搜集2003-2009年本院收治的影像和临床资料完整的局部晚期和局部-区域复发性乳腺癌患者111例胸部CT片.将淋巴结引流区分为以下亚结构:锁骨上内侧组(SC-M)、锁骨上外侧组(SC-L)、第Ⅰ站腋窝淋巴结(ALN-Ⅰ)、第Ⅱ站腋窝淋巴结(ALN-Ⅱ)、第Ⅲ站腋窝淋巴结(ALN-Ⅲ)、锁骨下淋巴结(IFN),肌间淋巴结(RN)、内乳淋巴结(IMN).统计各亚结构累及淋巴结频率及解剖特征.结果 共111例患者199处亚结构进入分析,其中SC-M 33处,SC-L 21处,ALN-Ⅰ 30处,ALN-Ⅱ25处,ALN-Ⅲ和IFN 35处,RN 27处,IMN 28处.锁骨上及腋窝是累及频率最高区域,达72.3%.SC中心平均深度分别为内侧组33.48 mm(＞3 cm者51.5%),外侧组45.62 mm(＞3 cm者71.4%).局部晚期患者和术后患者淋巴结在腋静脉头侧与脚侧比分别为5:20和64:28.IMN除2处外余26处均位于1～3肋间.复发IMN中心距表皮和体中线平均距离分别为24.23 mm和29.38 mm,与内乳血管横向距离为6.19 mm,纵向距离为5.73 mm.结论 区域淋巴结个体差异变化较大,传统固定野照射技术无法达到合理的剂量覆盖,建议采用CT定位为基础的三维适形计划优化.

Abstract：

Objective The frequency and the anatomic distribution of involved regional nodes in recurrent and locally advanced breast cancer were analyzed, in order to evaluate the rational of conventional regional node radiation technique and provide evidence for target definition of breast cancer . Methods Patients with recurrent or locally advanced breast cancer who were treated in our hospital from August 2003 to December 2009 were included in this study. 111 patients had contrast enhanced chest CT images of the whole regional nodes before treatment. The regional nodes were categorized into 8 anatomical substructures including medial and lateral supraclavicular nodes ( SC-M, SC-L), axilla nodes ( ALN )- Ⅰ , Ⅱ , Ⅲ,infraclavicular nodes (IFN), Rotter's nodes (RN) and internal mammary nodes (IMN). The frequency of involvement and anatomical distribution of the involved nodes on CT images were analyzed. Results A total of 111 patients were enrolled this study and 199 anatomical substructures with involved nodes were identified. The frequency of involvement were :SC-M 33, SC-L 21, ALN- Ⅰ 30, ALN-Ⅱ 25, ALN-Ⅲ + IFN 35, RN 27, IMN 28. Supraclavicular region and axilla were the most frequently involved area (72. 3% ).The average depth of the SC-M and SC-L nodes was 33.48 mm ± 10. 57 mm and 45.62 mm ±20. 45 mm,and 51.5% and 71.4% of the SC-M and SC-L nodes were located more than 3 cm deep from the skin. The axilla nodes were located cranial and caudal to the axillary vein in 5 and 20 locally advanced breast cancer patients and in 64 and 28 patients who received prior axillary dissection. The majority of involved IMN was located within the first 3 intercostal spaces (26/28). The average distance between the center of involved IMN and chest skin was 24. 23 mm ± 10. 28 mm. The average distance between the center of involved IMN and midline of the body was 29. 38 mm ±6. 7 mm. The center of involved IMN was 6.19 mm ±5.73 mm lateral and 5.73 mm ± 4. 56 mm posterior to the internal mammary vessels. Conclusions Conventional field design is unlikely to provide sufficient dose to the entire risk region because of individual differences.Individualized treatment planning based on CT would become feasible with increasing knowledge of natural risk of nodal involvement.     

皮肤建成区效应对早期乳腺癌全乳照射治疗计划评估的影响

背景与目的:调强放疗技术(intensity-modulated radiation therapy,IMRT)可以显著提高全乳放射治疗时乳房内的剂量分布,但全乳放疗中靶体积的确定和勾画存在一定的不确定性。本研究的目的是通过对正向调强方式下全乳放射治疗计划的剂量-体积直方图的分析,定量研究皮肤建成区效应对早期乳腺癌全乳放射治疗计划评估的影响。方法:22例Ⅰ、Ⅱ期乳腺癌保乳手术后需要做全乳放疗的患者,所有患者的治疗靶区均由一名有经验的放疗医师勾画,靶区的前界直接沿皮肤的轮廓勾画,后界沿胸壁的轮廓勾画,勾画的区域为临床靶区(clinical target volume,CTV),然后在前界和后界分别收缩0.5cm,形成另一个靶区CTV1。选择最佳角度的两个相对的切线野,用正向调强方式制定治疗计划,保证重要器官肺和心脏所接受的剂量体积比、每一层面的剂量分布都满足临床放疗要求。结果:CTV超过95%处方剂量的靶区体积百分比的平均值为(89.6±3.2)%,明显低于CTV1超过95%处方剂量的靶区体积百分比(96.5±2.0)%,(P<0.001);CTV的靶区剂量均匀性指数D99-01为(14.0±2.4)Gy,明显高于CTV1的D99-01(7.3±1.6)Gy,(P<0.001)。结论:皮肤建成区效应是早期乳腺癌全乳放疗中必须考虑的重要方面之一。定量认识建成区效应对治疗计划评估的影响,是有效实现乳腺癌全乳调强放疗技术在临床开展应用的一个重要环节。在调强治疗方式下,应该以扣除表面和建成区域的临床靶区体积来进行治疗计划的评估。     

Estimating the Value of Surgical Clips for Target Volume Delineation in External Beam Partial Breast Radiotherapy

AimsTo investigate the role of surgical clips in defining the clinical target volume (CTV) for three-dimensional conformal external beam radiotherapy-partial breast irradiation (3D-CRT-PBI) using preoperative computed tomography scans.Materials and methodsA group of patients with early breast cancer underwent conservative surgery with placement of surgical titanium clips (at least three clips required). All patients had a treatment planning computed tomography simulation before (CT1) and after surgery (CT2). The two sets of images were co-registered with a match point registration. The relationship between the clips-based CTV for PBI delineated on CT2 and the initial tumour location on CT1 was studied, evaluating the percentage of intersection volume.ResultsTwenty-eight patients participated in this study. In total, 13 patients (46.4%) had an intersection volume ≥ 50% and 10 patients (35.7%) had complete intersection (intersection volume = 100%). An increased median intersection volume was observed in patients with more than six clips (P = 0.007) and in patients with a larger portion of breast volume covered by the PBI-CTV (CTV/BV; P = 0.010). Intersection volume increased with the number of clips, after adjustment for CTV/BV (linear coefficient = 5.1693; P = 0.043). Also, a maximum distance from the chest wall ≤0.7 cm and CTV/BV > 9.5% were found to be predictors of an intersection volume ≥50% (area under the curve 0.841; confidence interval 0.649–0.952; P < 0.0001; area under the curve 0.800; confidence interval 0.607–0.926; P = 0.0004) and of an intersection volume of 100% (area under the curve 0.776, confidence interval 0.573–0.916, P = 0.046; area under the curve 0.752, confidence interval 0.536–0.935; P = 0.032).ConclusionsTitanium clips are essential and six or more increase the accuracy of tumour bed delineation for PBI; also the primary tumour location as well as the percentage of volume of breast covered by PBI-CTV may influence the correct delineation of PBI-CTV.     

Comparison of classic simulation and virtual simulation in breast irradiation: prospective study on 14 patients]

PURPOSE: To compare conventional 2D simulation and virtual simulation on 14 patients with breast cancer. PATIENTS AND METHODS: Patients were simulated for treatment using standard procedure. They subsequently underwent CT scan in the treatment position. The CTV was defined as breast tissue. The PTV was obtained by adding a 3D margin of 1 cm around CTV. Organs at risk (lungs and heart) were outlined. Ballistics and dose distribution obtained with the two planning methods were compared. RESULTS: With conventional simulation, 95% of CTV received 95% of the dose prescribed. Virtual simulation significantly improved dosimetric coverage of PTV without increasing irradiation volume of lung and heart. In 2D simulation, using three slices allowed optimisation by adjusting wedge angle. The five-slice plan was a much better predictor of the maximum dose regions when compared to the three-slice plan. Using entire CT data didn't give any benefit. CONCLUSION: Variations in CTV delineation and PTV definition limit interest of virtual simulation. In classic simulation, a 5 CT slice-plan can be used to optimise dose distribution.