Li Yi-Zhuo, Wu Pei-Hong, Huang Zi-Lin, Xie Chuan-Miao, Zhang Guo-Yi, Lu Ci-Yong, Li Li, Cai Pei-Qiang, Liu Xue-Wen
Imaging Diagnosis & Interventional Center, State Key Laboratory of Oncology in Southern China, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China.
Zhonghua Yi Xue Za Zhi. 2010 Dec 21;90(47):3347-50.
To evaluate the distributions of primary nasopharyngeal carcinoma (NPC) and the patterns of skull base involvement in NPC patients using magnetic resonance imaging (MRI).
After the approval of institutional review board and informed consent, 838 consecutive newly-diagnosed and untreated NPC patients were examined by MRI. Their MR images were reviewed by two independent radiologists.
Among all cases, the incidence rates of superior side and post-superior side involvement were 98.57% (826/838) and 98.21% (823/838) respectively. The differences were not significant between these two sides (P > 0.05). Lateral side erosion was demonstrated in 784 (93.56%) cases. Posterior side was involved in 391 (46.66%) cases. The total incidence rate of skull base involvement was 65.51% (549/838). According to the anatomic site, the pathways of skull base involvement were classified into 5 spreading routes: anterior; superior; super-lateral; super-anterior and super-posterior. According to the incidence rates and the results of chi-square test, the anatomic sites around the nasopharynx were classified into three groups of risk grades: high-risk (≥ 35%), medium-risk (≥ 5% - 35%) and low-risk (< 5%).
Skull base involvement of NPC spreads stepwise from proximal site to more distal sites. The area of skull base involvement in NPC is classified into high-grade, medium-grade and lower-grade groups respectively. The high and medium-grade groups are related with T3 stage while the lower-grade group T4 stage. Thus T3 stage should be subdivided into T3a and T3b. These schemes may be useful in a more accurate NPC staging and a delineation of clinical target volume for radiotherapy in NPC patients.
利用磁共振成像（MRI）评估鼻咽癌（NPC）的原发部位分布及NPC患者颅底受累模式。
经机构审查委员会批准并获得知情同意后，对838例连续的新诊断且未治疗的NPC患者进行MRI检查。由两名独立的放射科医生对其MR图像进行评估。
在所有病例中，上侧和后上侧受累的发生率分别为98.57%（826/838）和98.21%（823/838）。这两侧之间的差异无统计学意义（P>0.05）。784例（93.56%）出现外侧侵蚀。后侧受累391例（46.66%）。颅底受累的总发生率为65.51%（549/838）。根据解剖部位，颅底受累途径分为5种扩散途径：前；上；上外侧；上前和上后。根据发生率及卡方检验结果，将鼻咽周围的解剖部位分为三组风险等级：高风险（≥35%）、中风险（≥5% - 35%）和低风险（<5%）。
NPC的颅底受累从近端部位逐步扩散到更远端部位。NPC颅底受累区域分别分为高等级、中等级和低等级组。高等级和中等级组与T3期相关，而低等级组与T4期相关。因此，T3期应细分为T3a和T3b。这些方案可能有助于更准确地对NPC进行分期，并描绘NPC患者放疗的临床靶区。
