Word文档 - 二维码附录4
Word 文档下载:二维码附录4.docx
1鼻咽癌靶区勾画参考图
鼻咽癌照射靶区包括鼻咽大体肿瘤区、转移的颈部阳性淋巴结、亚临床病灶和预防区域,尽量避免或减少重要器官的照射。靶区勾画以MRI为基础,并通过内镜对鼻前间隙、鼻咽和口腔进行详细的临床检查,结合CT及PET/CT的影像,全面了解肿瘤的侵犯范围。有条件的单位可考虑增强MRI与计划CT融合进行勾画。靶区定义及勾画原则如下[1-4]:
(1)鼻咽肿瘤靶区(gross tumor volume of nasopharyngeal carcinoma, GTVnx):临床和影像学检查所见的鼻咽部原发肿瘤区域,包括转移的咽后淋巴结。
(2)颈部肿瘤靶区(gross tumor volume of cervix node, GTVnd):临床检查和(或)影像学所见的肿大淋巴结。在靶区勾画时,可根据双颈多个颈淋巴结灶设置多个GTVnd。
(3)临床靶区1(clinical target volume 1,CTV1):包括GTVnx及其周围的亚临床病灶区域,即GTVnx+5mm=CTV1。
(4)临床靶区2(clinical target volume 2,CTV2):在CTV1基础上再外扩5mm范围,即CTV1+5mm=CTV2。需充分考虑鼻咽解剖及肿瘤的生物学特性,根据肿瘤侵犯部位,针对不同的T分期,适当覆盖鼻腔后部、上颌窦后部、翼腭窝、部分后组筛窦、咽旁间隙、颅底、部分颈椎和斜坡,具体解剖界限与范围参照如下:① 前界:覆盖鼻腔后部5mm及上颌窦后部5mm。②后界:斜坡未受侵则覆盖斜坡前1/3;斜坡受侵则覆盖整个斜坡。③上界:包括犁骨和周围的筛窦,如果蝶窦受侵,后组筛窦的上面部分需要包进去,前组筛窦一般没必要预防照射;T1和T2期覆盖蝶窦下部,T3和T4期覆盖整个蝶窦;T1和T2期无需覆盖海绵窦,T3和T4期仅覆盖同侧整个海绵窦;无论T分期如何均覆盖双侧卵圆孔、圆孔和破裂孔,如果原发肿瘤向后外侧浸润或有高位颈部淋巴结肿大,还需要包括颈静脉孔和舌下神经管。④侧界:无论T分期如何都需覆盖整个咽旁间隙。此外,CTV2还需覆盖GTVnd、咽后淋巴结区,以及需要预防性照射的颈部淋巴结引流区(CTVnd),具体如下:
①咽后淋巴结区:咽后淋巴结作为鼻咽部淋巴引流的第一站,与原发肿瘤位置紧邻且关系密切[5, 6],因此对于咽后淋巴结CTV的勾画均应按原发肿瘤CTV1、CTV2处理。此外,无论是否存在转移,均需将双侧咽后淋巴结区涵盖在CTV2内。并且根据其解剖位置和转移特性将其上界定为颅底,下界定为C2椎体下缘,必要时可延至C3椎体下缘。需要特别指出的是,通常情况下CTV2只需覆盖外侧组咽后淋巴结区。虽然Lin等[3]的研究提出内侧组也应囊括在内,但是鉴于该组罕见转移[5, 7],并且扩大照射范围势必造成邻近肌肉的损伤,从而增加吞咽困难等并发症的发生风险[8-9],因此该种勾画方式的可行性仍有待验证。
②CTVnd:尽管RTOG倾向于对除N0外的NPC患者均进行I-V区全颈淋巴结预防性照射[10-11],但随着现代放射成像技术的发展,我们对NPC淋巴结转移的诊断能力大幅提高,并且对淋巴扩散的模式也有了更深入的认识[12]。越来越多的临床研究结果表明采用选择性颈部淋巴结预防性照射(elective neck irradiation,ENI)的方式能够在不降低疗效的同时减少并发症的发生[13, 14]。因此我们建议采用ENI的方式勾画,N0期CTVnd: 无肿大或可疑转移淋巴结时,仅需覆盖双侧Ⅱ、Ⅲ、Va区;仅存在单侧颈部可疑转移淋巴结(高危区,肿大,但未达阳性标准)时,需覆盖同侧Ⅱ-V区和对侧Ⅱ、Ⅲ、Va区;若双侧均存在可疑转移淋巴结时,则需覆盖双侧Ⅱ-V区。N1-3期CTVnd:仅存在单侧颈部转移淋巴结时,需覆盖同侧Ⅱ-V区和对侧Ⅱ、Ⅲ、Va区;若双侧均存在转移淋巴结时,则需覆盖双侧Ⅱ-V区。Ib区CTVnd: 由于Ib区少见淋巴结转移和复发[15],而覆盖Ib区将增加颌下腺的受照体积,加剧口干[16]。因此通常不推荐将Ib区涵盖于靶区内,但如果出现以下情况,则可考虑将同侧Ib区纳入CTVnd[2, 17-18]:Ib区存在转移淋巴结,或该区阳性淋巴结切除术后;Ⅱ区转移淋巴结存在包膜外侵或轴位最大径>2cm;同侧颈部多个区域(≥3个)存在转移淋巴结;肿瘤侵犯颌下腺;肿瘤侵犯口腔或鼻腔的前半部。
注意事项: 除非肿瘤侵犯颌下腺,否则在勾画Ib区CTVnd时应尽可能减少其受照射体积。除非淋巴结术后或皮肤受侵犯者,否则CTVnd所对应的计划靶区(PTVnd)不应超出皮肤,推荐距皮肤下2-3mm为宜。
如果肿瘤毗邻OARs,肿瘤外扩推荐:GTV+1mm=CTVp1;CTVp1+2mm=CTVp2;有专家建议,对于T3、T4期原发肿瘤毗邻OARs,推荐GTV外只勾画CTV1,CTV包括上述高危区域。对于靶区和正常组织的取舍,不同的中心不同的医生有不同的判断标准。
2靶区勾画示意图
为方便和国际指南对照,靶区采用与国际指南相同的颜色:国际指南的GTVp =本示意图GTVnx;国际指南的GTVn =本示意图GTVnd;国际指南的CTV1 =本示意图CTV1;国际指南的CTV2 =本示意图CTV2。
图1 T1N0M0
注:靶区勾画颜色, GTVnx为红色,CTV1为绿色,CTV2为蓝色。
图2 T3N1M0
注:靶区勾画颜色为GTVnx、GTVnd、CTV1、CTV2。
参考文献
[1]Liang SB, Sun Y, Liu LZ, et al. Extension of local disease in nasopharyngeal carcinoma detected by magnetic resonance imaging: improvement of clinical target volume delineation[J]. Int J Radiat Oncol Biol Phys, 2009, 75(3):742-750.
[2]Lee AW, Ng WT, Pan JJ, et al. International guideline for the delineation of the clinical target volumes (CTV) for nasopharyngeal carcinoma [J]. Radiother Oncol, 2018, 126(1): 25-36.
[3]Lin L, Lu Y, Wang XJ, et al. Delineation of neck clinical target volume specific to nasopharyngeal carcinoma based on lymph node distribution and the international consensus guidelines[J]. Int J Radiat Oncol Biol Phys, 2018, 100(4):891-902.
[4]虞鲁诗,宋启斌,韩光. 2017鼻咽癌国际临床靶区勾画指南解读[J]. 肿瘤防治研究,2019,46(1):85-92.
[5]Liu LZ, Zhang G, Xie C, et al. Magnetic resonance imaging of retropharyngeal lymph node metastasis in nasopharyngeal carcinoma: patterns of spread[J]. Int J Radiat Oncol Biol Phys, 2006, 66(3): 721-730.
[6]Wang XS, Hu CS, Ying HM, et al.Patterns of retropharyngeal node metastasis in nasopharyngeal carcinoma[J]. Int J Radiat Oncol Biol Phys, 2009,73(1):194-201.
[7]Wang XS, Yan C, Hu CS, et al. Study of the medial group retropharyngeal node metastasis from nasopharyngeal carcinoma based on 3100 newly diagnosed cases[J]. Oral Oncol, 2014, 50(11): 1109-1113.
[8]Feng FY, Kim HM, Lyden TH, et al.Intensity-modulated radiotherapy of head and neck cancer aiming to reduce dysphagia: early dose-effect relationships for the swallowing structures[J]. Int J Radiat Oncol Biol Phys, 2007, 68(5): 1289-1298.
[9]Paleri V, Roe JW, Strojan P, et al. Strategies to reduce long-term postchemoradiation dysphagia in patients with head and neck cancer: an evidence-based review[J]. Head Neck, 2014. 36(3): 431-443.
[10]Lee N, Harris J, Garden AS, et al. Intensity-modulated radiation therapy with or without chemotherapy for nasopharyngeal carcinoma: radiation therapy oncology group phase II trial 0225[J]. J Clin Oncol, 2009,27(22): 3684-3690.
[11]Caglar HB, Tishler RB, Othus M, et al. Dose to larynx predicts for swallowing complications after intensity-modulated radiotherapy[J]. Int J Radiat Oncol Biol Phys, 2008, 72(4): 1110-1118.
[12]Ho FC, Tham IW, Earnest A, et al. Patterns of regional lymph node metastasis of nasopharyngeal carcinoma: a meta-analysis of clinical evidence[J].BMC Cancer, 2012,12:98.
[13]Li JG, Yuan X, Zhang LL, et al. A randomized clinical trial comparing prophylactic upper versus whole-neck irradiation in the treatment of patients with node-negative nasopharyngeal carcinoma[J]. Cancer, 2013,119(17):3170-3176.
[14]Chen JZ, Le QT, Han F, et al. Results of a phase 2 study examining the effects of omitting elective neck irradiation to nodal levels IV and Vb in patients with N(0-1) nasopharyngeal carcinoma[J]. Int J Radiat Oncol Biol Phys, 2013,85(4):929-934.
[15]Wang X, Hu C, Ying H, et al. Patterns of lymph node metastasis from nasopharyngeal carcinoma based on the 2013 updated consensus guidelines for neck node levels[J]. Radiother Oncol, 2015, 115(1): 41-45.
[16]Pow EH, Kwong DL, Sham JS,et al. Can intensity-modulated radiotherapy preserve oral health-related quality of life of nasopharyngeal carcinoma patients?[J]. Int J Radiat Oncol Biol Phys, 2012, 83(2): e213-221.
[17]Zhang F, Cheng YK, Li WF, et al. Investigation of the feasibility of elective irradiation to neck level Ib using intensity-modulated radiotherapy for patients with nasopharyngeal carcinoma: a retrospective analysis[J]. BMC Cancer, 2015, 15: 709.
[18]Ou X, Miao Y, Wang X, et al. The feasibility analysis of omission of elective irradiation to level IB lymph nodes in low-risk nasopharyngeal carcinoma based on the 2013 updated consensus guideline for neck nodal levels[J]. Radiat Oncol, 2017,12(1): 137.
点击数:9979