The Role Of Diffusion-weighted Magnetic Resonance Imaging In Hypopharyngeal Carcinoma

ObjectiveTo evaluate the value of magnetic resonance diffusion-weighted imaging (DWI), combined with routine MRI, and apparent diffusion coefficient (ADC value) in hypopharyngeal cancer diagnosis, differential diagnosis, degree of differentiation and stage.Materials and methodsThis study collected a total of38patients with hypopharyngeal cancer, total13cases of patients with hypopharynx benign disease, hypopharyngeal cancer cases are all of pharyngeal biopsy or surgical pathology confirmed. All patients were performed routine MRI and DWI scans, and analysis of conventional MRI, DWI features and apparent diffusion coefficient (ADC) values. Compare to conventional MRI with conventional MRI combined DWI and ADC values in hypopharyngeal cancer diagnosis accuracy and specificity, comparing the the average ADC values of hypopharyngeal cancer with hypopharynx benign disease,using ROC curve b1000value under one of the best threshold for hypopharyngeal cancer diagnosis, and calculated the sensitivity and specific degrees, comparing the average ADC values of different differentiation degrees of hypopharyngeal cancer, comparing the average ADC values of neck lymph node between metastatic and nonmetastatic groups of hypopharyngeal carcinoma, comparing the average ADC values of different T staging of hypopharyngeal carcinoma, using SPSS19.0software, analyzing differences between ADC values in each group.ResultGeneral clinical data of38cases of patients with hypopharyngeal cancer (36male and1female, the average age of61.0years (42-80years); Intraoperative or postoperative pathological diagnosis:all were squamous cell carcinoma.27(71.1%) cases were in the piriform fossa,7cases (18.4%) were in the pharynx posterior wall,4cases (10.5%) were in the postcricoid region.34patients (89.5%) had a history of smoking,29patients had a history of drinking, with25patients smoking and drinking. Clinical stages:the stage Ⅱ2case (5.3%), the stage III10cases (26.3%), stage IV26cases (68.4%).Prediction of38cases of hypopharyngeal cancer by conventional MRI in the diagnosis of33cases of malignant tumor, the sensitivity is86.8%.Comparing the average ADC values of hypopharyngeal cancer with hypopharynx benign disease,and determine the hypopharyngeal cancer diagnosis threshold ADC:38cases of hypopharyngea cancer in DWI are characterized by high signal, ADC=1.0130±0.03338×10-3mm2/s.13patients with hypopharynx benign disease:9cases of DWI high signal (69.2%),1case for such as signal (7.7%),3cases (23.1%) of no obvious abnormal signal, ADC=1.5454±0.1198×10-3mm2/s, compared to both ADC values has obvious difference (p<0.001). The area under the ROC curve was0.934±0.033, when1.0750×10-3mm2/s Youden index is1.789, the diagnostic sensitivity and specificity are100%,78.9%, respectively.Hypopharyngeal cancer various degrees of differentiation ADC values were:well differentiated group1.06×10-3mm2/s、well-moderately-differentiated group0.9979±0.0362x10-3mm2/s、moderately differentiated group1.0963±0.1125×l0-3mm2/s moderately-poorly-differentiated group1.0463±0.0988×10-3mm2/s、poorly-differentiated group0.8874±0.0808×10-3mm2/s, The ADC values in all group except well differentiated group(because of only1case) are compared in pairs,the difference was not statistically significant (P>0.05).The average ADC values of neck lymph node between metastatic and nonmetastatic groups of hypopharyngeal carcinoma were:metastatic groupl.1260±0.1512×10-3mm2/s, nonmetastatic group0.8991±0.0486×10-3mm2/s, the difference was not statistically significant (t=1.783, p=0.083).The average ADC values of different T staging of hypopharyngeal cancer were:T2staging group0.9923±0.0354×10-3mm2/s> T3staging group1.0369±0.0517×10-3mm2/s、 T4staging groupl.0161±0.0630×10-3mm2/s,The ADC values in all group except T1staging group (because of only1case) are compared in pairs, the difference was not statistically significant (P>0.05).ConclusionDWI and quantitative index determination of ADC values were able to distinguish between hypopharyngeal cancer and hypopharynx benign disease. The ADC values less than1.0750×10-3mm/s is a preferable threshold to differentiate hypopharyngeal cancer from hypopharynx benign disease in our study.