Background Although parotid-sparing IMRT reduced the dose distribution of parotid, parotid region recurrence has been reported. was larger in case group than that in control group (6.0?cm test or Wilcoxon rank sum test for quantitative variables, and the chi-square test or Fisher exact test for categorical variables. Receiver operating characteristic (ROC) curve analysis was used to evaluate different cut-off points for SLD to discriminate case or control group. Binary logistic regression was used to estimate the correlation between multiple exposure factors and the PLNM. With a two-sided test, p value of <0.05 was considered statistically significant. Results Median age of the patients in this research was 42 (range, 9C67) years. All sufferers had Who all type III or II disease. And 41/63 (65.1?%) sufferers had been T3-4 disease. 47/63 (74.6?%) sufferers came to medical center due to Panobinostat a main complaint of the mass in neck. Table?1 showed the clinical features of individuals. And there were no significant Panobinostat difference in medical features between the case and control organizations. Table 1 Clinical features of individuals in case and control organizations Parotid lymph nodes metastasis Totally, there were 48 positive lymph nodes found in the 22 instances of PLNM. Of the 48 positive lymph nodes, 21 nodes were located in superficial intraparotid, 13 nodes in subparotid, 11 nodes in deep intraparotid, and 3 nodes in pre-auricular area, respectively. The median of largest transverse diameter of nodes Panobinostat in parotid was 1.0?cm (range, 0.4C3.1?cm). And the median of shortest transverse diameter in the largest aircraft of parotid node was 0.7?cm (range, 0.4C2.0?cm). There were 10 instances of ENS and 8 instances of necrosis in metastatic parotid nodes. Fig.?1 showed one NPC patient with parotid lymph nodes metastasis, and the extensive lymphadenopathy can be seen in ipsilateral neck. Fig. 1 One NPC patient with superficial and deep intraparotid nodes metastasis. a. Transverse T2WI; b. Transverse T1WI with contrast enhancement; c. Sagittal T1WI with contrast enhancement in the ipsilateral neck Regional lymph nodes metastasis in case and control organizations (Table?2) Table 2 Ipsilateral neck lymph nodes metastasis in case and control organizations Involvement of RPN was found in 53/66 (80.3?%) sides. ENS and necrosis in RPN were found in 43/66 (65.2?%) and 20/66 (30.3?%) sides, respectively. RPN involvement, ENS, necrosis, and SLD showed no significant difference in case and control group. Level II contained IIa and Rabbit Polyclonal to OR52A4 IIb subareas. All individuals with this study were involved with level II. ENS and necrosis in level II were found in 59/66 (89.4?%) and 44/66 (66.7?%) sides. And level II necrosis in case group was significantly higher than that in control group (86.4?% vs. 56.8?%, p?=?0.016). The median of SLD in level II was Panobinostat 4.5?cm (range, 1.0C14.7?cm) in the sets. And the SLD of level II in case group was larger than that in control group (median, 6.0 vs. 3.6?cm, p?=?0.003). Level III involvement, ENS, and necrosis was found in 45/66 (68.2?%), 33/66 (50.0?%), and 14/66 (21.2?%) sides in this study, respectively. The median of SLD in level III was 0.9?cm (range, 0C7.2?cm). And no significant difference in level III involvement, ENS, necrosis, and SLD was found in case and control organizations. Level IV involvement, ENS, and necrosis were found in 21/66 (31.8?%), 15/66 (22.7?%), 4/66 (6.1?%) sides in this study, respectively. And no significant difference in level IV involvement, ENS, necrosis, and SLD was found Panobinostat in case and control organizations. Level Va/b involvement was found in 19/66 (28.8?%) sides in this study. And the rate of level Va/b involvement was higher in case group than that in control group (45.5?% vs. 20.5?%, p?=?0.034). There was no significant difference in ENS, necrosis, and SLD in level Va/b between the two organizations. Rare-neck areas with this study contained level Ia/b, Vc and VIa/b. And level Ia/b, Vc and VIa/b involvement were found in 6, 8, and 2 sides in case group, respectively. The pace of rare-neck areas involvement was higher in case group than that in control group (54.5?% vs. 13.6?%, p?p?=?0.003). 5.0?cm (5.0 vs. <5.0) was selected as the cut-off.