ABSTRACT
Objective@#To investigate the high-risk factors for parotid lymph node (PLN) metastasis from nasopharyngeal carcinoma (NPC) and evaluate the feasibility of local intensity-modulated radiotherapy (IMRT) in patients with high-risk NPC.@*Methods@#Clinical data of 440 NPC patients admitted to Department of Radiotherapy of Jiangsu Cancer Hospital from May, 2011 to March, 2017 were collected. The imaging features, treatment strategies and clinical prognosis of PLN metastasis were retrospectively analyzed. The whole group adopts the technique of intensity modulated radiotherapy. Total parotid or partial parotid irradiation, selective PLN irradiation, X-Ray and/or electronic line supplementation, dose 45-60 Gy. The χ2 test or Fisher′s accurate probability method test and single factor analysis, Logistic regression model multi-factor analysis. Kaplan-Meier survival analysis, log-rank test differences.@*Results@#PLN was observed in the parotid of 230 cases. At the end of follow-up, 11 patients (2.5%, 11/440) were diagnosed with PLN metastases. Among 11 cases, 9 patients (81.8%) had PLN size ≥5 mm. Multivariate analysis demonstrated that extracapsular spread of level Ⅱ was an independent risk factor for PLN metastasis. The patients with PLN size ≥5 mm or extracapsular spread of level Ⅱ were assigned into the high-risk PLN metastasis group. The patients in the high-risk group were further divided into the radiotherapy and non-radiotherapy subgroups. Survival analysis demonstrated that for 230 patients with PLN metastasis, the local recurrence-free survival (LRFS) significantly differed, whereas the overall survival (OS), disease metastasis-free survival (DMFS) and progression-free survival (PFS) did not considerably differ between the radiotherapy and non-radiotherapy subgroups in the high-risk PLN metastasis patients.@*Conclusions@#The PLN metastasis rate of NPC is low. Extracapsular spread of level Ⅱ is an independent risk factor. Radiotherapy of the parotid region is considered for patients with PLN size≥5 mm or those with PLN size<5 mm complicated with extracapsular spread of level Ⅱ.
ABSTRACT
Objective To investigate the high-risk factors for parotid lymph node (PLN) metastasis from nasopharyngeal carcinoma (NPC) and evaluate the feasibility of local intensity-modulated radiotherapy (IMRT) in patients with high-risk NPC.Methods Clinical data of 440 NPC patients admitted to Department of Radiotherapy of Jiangsu Cancer Hospital from May,2011 to March,2017 were collected.The imaging features,treatment strategies and clinical prognosis of PLN metastasis were retrospectively analyzed.The whole group adopts the technique of intensity modulated radiotherapy.Total parotid or partial parotid irradiation,selective PLN irradiation,X-Ray and/or electronic line supplementation,dose 45-60 Gy.The x2 test or Fisher's accurate probability method test and single factor analysis,Logistic regression model multifactor analysis.Kaplan-Meier survival analysis,log-rank test differences.Results PLN was observed in the parotid of 230 cases.At the end of follow-up,11 patients (2.5％,11/440) were diagnosed with PLN metastases.Among 11 cases,9 patients (81.8％) had PLN size ≥5 mm.Multivariate analysis demonstrated that extracapsular spread of level Ⅱ was an independent risk factor for PLN metastasis.The patients with PLN size ≥ 5 mm or extracapsular spread of level Ⅱ were assigned into the high-risk PLN metastasis group.The patients in the high-risk group were further divided into the radiotherapy and non-radiotherapy subgroups.Survival analysis demonstrated that for 230 patients with PLN metastasis,the local recurrence-free survival (LRFS) significantly differed,whereas the overall survival (OS),disease metastasis-free survival (DMFS) and progression-free survival (PFS) did not considerably differ between the radiotherapy and nonradiotherapy subgroups in the high-risk PLN metastasis patients.Conclusions The PLN metastasis rate of NPC is low.Extracapsular spread of level Ⅱ is an independent risk factor.Radiotherapy of the parotid region is considered for patients with PLN size≥5 mm or those with PLN size＜5 mm complicated with extracapsular spread of level Ⅱ.