Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Japan.
Br J Radiol. 2011 Mar;84(999):265-70. doi: 10.1259/bjr/47164832. Epub 2010 Oct 19.
The purpose of this study was to investigate factors associated with lymph node (LN) metastasis to identify which nasopharyngeal cancer (NPC) patients can undergo a reduction in the prophylactic radiation field. MRI of biopsy-proven NPC patients was evaluated to determine primary tumour extension and the existence of LN metastasis.
Sex, age, pathological type, T stage, primary tumour size, existence beyond the midline of the nasopharynx at the primary site and parapharyngeal extension of the primary tumour were assessed regarding their impact on the laterality of LN metastasis using the χ(2) test.
Of the 167 patients, 149 (89%) showed nodal involvement. The existence beyond the midline of the nasopharynx was significantly associated with the laterality of LN metastasis (p<0.0001). Most patients (82%) with primary tumour presence within the midline showed only ipsilateral LN metastasis or no LN metastasis. In addition, contralateral LN metastases were seen only at Level II and the retropharyngeal LN among most of other patients.
These results suggest that LN areas other than Level II and the retropharyngeal LN on the contralateral side could be omitted in patients with primary tumour presence within the midline and without the contralateral Level II or the retropharyngeal LN. Whether disease control is compromised by reducing the radiation field for subclinical diseases is a problem that should be solved in the future by prospective study.
本研究旨在探讨与淋巴结（LN）转移相关的因素，以确定哪些鼻咽癌（NPC）患者可以减少预防性照射野。通过评估经活检证实的 NPC 患者的 MRI，确定原发肿瘤的延伸范围以及是否存在 LN 转移。
使用 χ(2)检验评估性别、年龄、病理类型、T 分期、原发肿瘤大小、原发肿瘤在鼻咽中线的位置以及咽旁延伸对 LN 转移侧别的影响。
在 167 例患者中，149 例（89%）存在淋巴结受累。鼻咽中线以外的存在与 LN 转移的侧别显著相关（p<0.0001）。大多数（82%）中线内原发肿瘤的患者仅出现同侧 LN 转移或无 LN 转移。此外，大多数其他患者仅在同侧 II 区和咽后淋巴结中可见对侧 LN 转移。
这些结果表明，对于中线内存在原发肿瘤且无对侧 II 区或咽后淋巴结的患者，可以省略对侧 II 区和咽后淋巴结以外的 LN 区域。减少亚临床疾病的照射野是否会影响疾病控制是一个需要通过前瞻性研究解决的问题。
