[Application of magnetic resonance imaging to clinical classification of nasopharyngeal carcinoma].
OBJECTIVE
The clinical classification of nasopharyngeal carcinoma (NPC) depends mainly on the materials of medical imaging. This study was to investigate the application of magnetic resonance imaging (MRI) to the clinical classification of NPC.


METHODS
One hundred patients with NPC confirmed by pathohistology received MRI and computed tomography (CT) within 15 days before treatment from May 2002 to Jun. 2005. The patients included 74 men and 26 women with a median age of 46 (21-60). The detection rates of involved sites by MRI and CT were calculated and compared using Chi(2) test. The clinical classification was performed according to 92'staging system of China. The constituent ratios of cases at different T, N, and clinical stages classified by MRI and CT were analyzed by Chi(2) test.


RESULTS
The detection rates of skull base bone destruction and retropharyngeal lymph node involvement were significantly lower by CT than by MRI (31.0% vs. 56.0%, Chi(2)=12.715, P=0.000; 40.0% vs. 55.0%, Chi(2)=4.511, P=0.034). The constituent ratio of cases at T1-T4 stages classified by MRI was different from that classified by CT (Chi(2)=8.339, P=0.039), but there was no difference in N staging (Chi(2)=0.275, P =0.965) and clinical classification (Chi(2)=5.525, P=0.137).


CONCLUSIONS
MRI is more sensitive than CT in detecting skull base bone destruction and retropharyngeal lymph node involvement of NPC. MRI may upstage T classification, tends to upstage clinical classification, and has no influence on N classification of NPC.
Cao
Ka-Jia
KJ
State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, PR China. caokajia@mail.sysu.edu.cn
Xie
Chuan-Miao
CM
Huang
Pei-Yu
PY
Hu
Dan
D
Sun
Rui
R
Chen
Qiu-Yan
QY
D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000473:pathology*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000379:methods*; D019291:Skull Base / Q000473:pathology; D014057:Tomography, X-Ray Computed; D055815:Young Adult