ABSTRACT
Objective:According to 2013 updated consensus guidelines of neck node levels, the distribution characteristics of cervical lymph nodes of nasopharyngeal carcinoma (NPC) were analyzed, aiming to provide preliminary reference for the clinical target volume (CTV) delineation of level Ⅴ in NPC.Methods:A total of 1110 patients pathologically diagnosed with NPC from 2012 to 2020 were retrospectively recruited for further analysis. All patients’ MRI and contrast-enhanced CT simulation scan imageswere retrospectively reviewed, metastatic lymph nodes were mapped using the 2013 International Consensus Guidelines. Then, the correlation between Ⅴa, Ⅴb and Ⅴc metastatic lymph nodes and other lymph nodes was analyzed. An NPC case diagnosed with T 1N 0M 0 was selected as the baseline standard for the normal anatomical structure and proportion of Ⅴc area. The metastatic lymph nodes in Vc were delineated on the CT simulation scan image of sample case, and the distribution characteristics of the metastatic lymph nodes inⅤc were analyzed. Results:Among the 1110 patients, 1004(90.5%) patients had lymph node metastases. The most common area of metastatic lymph node levels were level Ⅶa (74.7%) and level Ⅱb(70.7%), and the skip metastasis of lymph nodes was rare (1.0%). The multivariate analysis showed lymph node metastasis in level Va was correlated with levels Ⅱb, Ⅲ, Ⅳa, Ⅴb, and Ⅷ region ( P=0.010, 0.001, 0.001, 0.001, 0.037). Lymph node metastasis in level Ⅴb was correlated with levels Ⅲ, Ⅳa, Ⅴa and Ⅴc region ( P=0.006, 0.001, 0.001, 0.001). Lymph node metastasis in level Ⅴc was correlated with levels Ⅳb and Ⅴb region ( P=0.008, 0.001). There were 28 cases of lymph node metastasis in levelⅤc. A total of 38 metastatic lymph nodes were counted in level Vc. Among them, 33(86.8%) lymph nodes were located in the medial of the omohyoid muscle (Ⅴc-1 region), and 5(13.2%) were located in the lateral of the omohyoid muscle (Ⅴc-2 region). Conclusions:This study reflects the principle of individualized CTV delineation, which is based on the levels of nodal spread in NPC patients. When correlation is observed among different level V, V should be delineated as the moderate risk lymphatic drainage (CTV n2). It is recommended to individualized delineate level Vc when the CTV n2 covers Vc. The Ⅴc-2 region should be delineated as CTV n2 only when there is nodal spread in the ipsilateral Ⅴc-1 region.
ABSTRACT
Objective: To retrospectively compare the prognosis between patients with locally advanced T and N stage nasopharyngeal carcinoma (NPC), to provide a reference for the clinical treatment of NPC. Methods: A total of 264 NPC cases from December 2011 to November 2017 visiting The General Hospital of Western Theater Command were pathologically diagnosed and retrospectively analyzed. Of these, 102 and 162 were locally advanced T and N stage, respectively. Results: The two groups 5-year overall survival (OS), progression-free survival (PFS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were compared. These were 82.8% and 75.8% (P=0.271), 73.7% and 62.8% (P=0.043), 87.6% and 91.6% (P=0.646), 87.7% and 79.5% (P=0.066), respectively. Conclusions: The DMFS, OS and PFS decreased in patients with locally advanced N stage NPC, although there was no statistical difference. The significance of systemic and stratified treatment should be emphasized in patients with locally advanced N stage NPC in order to achieve a higher OS rate and reduce distant metastasis.
ABSTRACT
Objective:To retrospectively investigate the regulation of cervical and posterior to level V (PLV) lymph node metastasis on clinical target delineation in radiotherapy for nasopharyngeal carcinoma (NPC). Methods:A total of 428 NPC cases from February 2013 to April 2016 were subjected to enhanced CT scan from the base of the skull to the clavicle for pathological diagnosis. A deputy chief physician and an attending physician assessed the nodal distribution in each level in accordance with the RTOG guidelines proposed in 2013. The central point of the metastatic lymph nodes of PLV in the patients were recreated proportionally on the CT images of a stan-dard patient with N0 NPC in reference to the normal anatomy of the PLV area. SPSS 19.0 was used to analyze the correlation between PLV and the other levels. Moreover, the nodal location and characteristics of PLV were analyzed. Results:Among the 428 patients, 381 (89.0%) showed nodal involvement. The top four metastatic probabilities were presented as follows:Ⅱb (75.2%),Ⅶa (60.3%),Ⅱa (59.6%), andⅢ(42.0%). Up to 21 (4.9%) patients exhibited nodal involvement of PLV with 32 nodes. The mean vertical distance of all central points of PLV from the anterior border of the trapezius was 16 mm. Correlation analysis indicated the nodal involvement of PLV with the ipsilateral level Va (P=0.001). Conclusion:NPC showed a high probability of nodal metastasis. Nodes were mostly metasta-sized from the upper to the lower level, as well as from the proximal to the distal area. The leap metastasis rate was very low. The nod-al involvement of PLV correlated with the ipsilateral metastasis of level Va. Thus, the ipsilateral delineation of the posterior border of level V should be contoured to 25 mm far from the anterior surface of the trapezius during the nodal involvement of level Va.