摘要
调强放疗提高了局部和区域控制率,降低了并发症,是鼻咽癌放疗发展的方向。CT和MRI融合能更充分展示鼻咽癌原发病变范围,被认为是目前较理想的影像模式;目前困扰颈淋巴结范围描绘的关键因素是怎样将颈淋巴结分区转换为CT层面可描绘的影像边界,欧美共同描绘规范缩小了各肿瘤中心在勾画颈淋巴结区域时的差异而值得推荐;世界各主要肿瘤中心鼻咽癌调强计划规范中,大体肿瘤区的定义基本一致,且处方剂量接近甚至高于80Gy,主要差异是对鼻咽CTV范围的定义及鼻咽CTV和上颈部的处方剂量方案。根据随访结果分析,建议鼻咽CTV的范围除在鼻咽原发肿瘤外扩一定边径外,还应包括整个鼻咽腔、咽后淋巴结区、斜坡、颅底骨质结构、翼腭窝、咽旁间隙、部分蝶窦、鼻腔和上颌窦后1/3,且处方剂量宜≥60Gy;双侧上颈部应列为高危淋巴结转移区,施予至少60Gy的照射量。
Intensity modulated radiotherapy （IMRT） has increased the local-regional control rate and decreased the complications of radiotherapy for nasopharyngeal cancer（NPC）. CT and MRI fusion is currently the optimal modality to delineate the extent of the primary spread of this disease. The key factor affecting neck node delineation is how to translate anatomic node regions into the CT boundaries. The consensus guidelines that narrowed the gap among different cancer centers are recommended for delineating the boundary of the cervical lymph node regions. The definition of the gross tumor volume （GTV） of NPC is clear and is almost the same among the main cancer centers in their IMRT planning protocols. The actual dose to the GTV is close to or more than 80 Gy. The main differences among those cancer centers lay in the definition of the CTV, its dose prescription scheme, and the dose to the high cervical region. Their long-term followup results suggested that, beside the 5 mm-10 mm margins, the immediate high risk structures （including the entire nasopharyngeal cavity, retropharyngeal space, clivus, base of the skull, pterygoid plates and muscles, parapharyngeal space, the sphenoid and partial ethmoid sinuses, the posterior third cff the maxillary sinuses and the nasal cavity） should also be included in the delineation and should be treated with more than 60 Gy. Bilateral node level Ⅰ b, Ⅱ and Ⅴ a should be ranked as high risk regions and differentially treated with no less than 60 Gy.
出处
《中国肿瘤临床》
CAS
CSCD
北大核心
2008年第3期173-177,共5页
Chinese Journal of Clinical Oncology
关键词
鼻咽癌
调强放疗
靶区
描绘
剂量
Nasopharyngeal cancer
IMRT
Target
Delineation
Dose prescription
