Prognostic value of maximum diameter in axial plane of primary tumor on MRI in nasopharyngeal carcinoma / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the prognostic value of maximum diameter in axial plane of primary tumor (MDAPPT) on MRI in nasopharyngeal carcinoma (NPC).Methods From 2005 to 2007,333 patients with newly diagnosed and biopsy-proven NPC without distant metastasis,who underwent MRI scans of the nasopharynx and neck,were included in our study.MDAPPT was measured on MRI.The univariate analysis with the log-rank test and multivariate analysis with the Cox proportional hazards model were used to analyze the relationship between MDAPPT and prognosis.Results The median values of MDAPPT in patients with T1,T2,T3,and T4 NPC were 21.2,30.0,38.0,and 52.3 mm,respectively.For all patients with a MDAPPT of ≤30 mm,＞ 30-50 mm,and ＞ 50 mm,the 5-year overall survival (OS) rates were 81.3％,70.1％,and 51.5％,respectively (P =0.000) ; the 5-year progression-free survival (PFS) rates were 81.3％,70.0％,and 48.9％,respectively (P =0.000) ;the 5-year distant metastasisfree survival (DMFS) rates were 85.5 ％,86.5 ％,and 67.2 ％,respectively (P =0.000) ; the 5-year local relapse-free survival (LRFS) rates were 97.7％,91.5％,and 83.3％,respectively (P =0.013).The multivariate analysis showed that MDAPPT was a prognostic factor for PFS and DMFS.For the T3-T4 patients with a MDAPPT of ≤50 mm and ＞50 mm,the 5-year OS rates were 69.4％ and 52.2％ (P =0.004),the 5-year PFS rates were 68.0％ and 49.6％ (P =0.001),and the 5-year DMFS rates were 84.0％ and 66.8％ (P=0.001).In the patients with a MDAPPT ≤30 mm,the 5-year LRFS rates for those with T1,T2,T3,and T4 NPC were 10 0 ％,9 5.8 ％,9 6.3 ％,and 10 0 ％,respectively (P =0.6 4 3).Conclusions MDAPPT is a prognostic factor for PFS and DMFS in NPC,and it is an important prognostic factor in patients with T3-T4 NPC.In the NPC patients with a small MDAPPT,local control rate varies little in different T stages.