Studies Of CTP In Primary Laryngeal Squamous Carcinoma, Recurrent Disease, Post-radiation Changes, And Associated Metastatic Lymph Nodes Using DWI Technique

Objective:To evaluate whether there are differences in the perfusion parameters when choosing the ipsilaterl or contralateral common carotid artery compared to the lesion as the reference artery in PCT study of the neck at the common carotid artery, and the repeatability in the measurement of the perfusion parameters; To prospectively evaluate early changes in primary tumor perfusion parameters during concomitant cisplatin-based chemoradiotherapy of locoregionally advanced parimary laryngeal squamous cell carcinoma and to evaluate their predictive value for response of the primary tumor to therapy. And we sought to evaluate the routine clinical use of perfusion computed tomography in the differentiation of recurrent laryngeal squamous cancers and tissue changes after radiation treatment; To evaluate the value of echo-planar diffusion-weighted MR imaging (DWI) in the diagnosis of cervical metastatic lymph nodes with laryngeal squamous cell carcinoma, Analyse the realationship between the ADC values and grading of metastatic lymph nodes.Materials and methods:1.This study included 32 patients with confirmed primary laryngeal squamous cell carcinoma in our hospital. The perfusion data were transferred to a workstation (Advantage Windows 4.2; GE Medical Systems) running a commercial software package based on a deconvolution-based technique (Perfusion 3, body tumor). Two gaugers postprocessed the data respectively choosing the ipsilateral and contralateral common carotid artery as the reference artery and acquired the parameter maps and calculated the parameter values respectively. Statistical analysis consisted of paired t test and pearson product moment correlation coefficients. P<0.5 was considered significant; 2.49 patients were included in this study. Included Twenty three patients with locoregionally advanced primary laryngeal squamous cell carcinoma (received cisplatin-based chemoradiotherapy before surgery) and twenty six patients with suspected recurrent disease (received radiation therpy after surgery). Twenty three patients with locoregionally advanced primary laryngeal squamous cell carcinoma underwent perfusion CT and routine enhanced CT scans before therapy and after completion of 40 Gy and 70 Gy of chemoradiotherapy. BF, BV, MTT, PS and tumor volume of primary tumors were quantified. Differences in perfusion and tumor volume values during the therapy as well as between responders and nonresponders were analyzed, and the defferences in perfusion parameter values between the recurrent and no recurrent groups were analyzed too. Statistical analysis included paired t test, ANOVA, Sidak t test or Tamhane,s T2 test. And a receiver operating characteristic (ROC) curve analysis was performed; 3.35 consecutive patients with 55 enlarged (>10mm) cervical lymph nodes underwent MR imaging at 3.0-T MR. Cervical lymph node enlargement was secondary to metastases from primary laryngeal squamous cell carcinomas [n=25], lymphoma [n=11], reactive lymphadenitis [n=13], tubculosis of lymphy nodes [3]. For the 25 metastatic lymph nodes, highly differentiated [n=14], poorly differentiated [n=11]. DWI was performed using a single-shot echo-planar (SS-EPI) MR imaging sequence with b values (b:diffusion factor) of 0 and 1000s/mm2. Apparent diffusion coefficient (ADC) maps were reconstructed for all patients and ADC values were calculated for each lymph node of the 55 chosen lymph nodes. Pearson product moment correlation coefficients and ANOVA, Sidak t or Tamhane's T2 test. And a receiver operating characteristic (ROC) curve analysis was performed.Results:The BF, BV, MTT, PS values of the laryngeal primary squamous cell carcinoma between two gaugers using the ipislateral common carotid artery compared to the lesion as the reference artery correlated significantly, and there were no significantly difference in BF, BV, MTT, PS values between two gaugers(P>0.05). The BF, BV, MTT, PS values of the laryngeal primary squamous cell carcinoma between two gaugers using the contralateral common carotid artery compared to the lesion as the reference artery correlated significantly, and there were no significantly difference in BF, BV, MTT, PS values between two gaugers(P>0.05). There were no significantly differences between The BF, BV, MTT, PS values of the laryngeal primary squamous cell carcinoma using the ipislateral and contralateral common carotid artery compared to the lesion (P>0.05). The result demonstrated significant correlation between perfusion parameter values derived with contralateral common carotid artery as reference artery compared to the lesion and the ipsilateal common carotid artery reference, the pearson correlation coefficients were 0.84 (BV, P= 0.000),0.95 (BF, P=0.000),0.89 (MTT, P=0.000),0.84 (PS,P=0.000) respectively; The tumor volumes at 70 Gy were significantly lower compared with baseline values in the responders. In the nonresponders, measurements after 40 Gy showed a significant trend of increased BF, BV and PS values compared with the baseline values (P<0.05). In the responders, a significant reduction of BF values was recorded after 40 Gy (P=0.04) and after 70 Gy (P=0.01). BV values showed a reduction after 40 Gy followed by a plateau after 70 Gy (P=0.04). Baseline BV predicted short term tumor response with a sensitivity of 83.33% and specificity of 100%(P=0.01). After completion of 40 Gy of concomitant chemoradiation BV was a more significant predictor than were BF and MTT. The mean BV and PS values of tissue changes after radiation treatment were highly significantly different than those obtained in the recurrent disease (P>0.05). The mean BF and MTT values of tissue changes after radiation treatment were highly significantly different than those obtained in the recurrent disease (P<0.05); There were singnificantly differences in ADC values of metastatic lymph nodes with primary laryngeal squamous cell carcinoma compared with lymphoma as well as benign lymph nodes(P<0.05). In the metastatic lymph nodes with parimary laryngeal squamous cell carcinoma, ADC values of highly differentiated metastatic nodes were significantly higher than that of poorly differentiated metastatic nodes as well as lymphoma. There was not significantly defference in the ADC values between the poorly differentiated metastatic nodes and lymphoma. The threshold ADC value differentiating malignant and reactive lymphadenitis was 0.94x 10-3mm2/s.Conclusion:The measurement of perfusion CT parameters showed good repeatability in primary laryngeal squamous cell carcinoma. The results of this study demonstrated significantly correlations between perfusion parameter values derived with contralateral common carotid artery as reference artery compared to the lesion and the ipsilateal common carotid artery, and there was not significantly difference between them too, supporting the action that the ideal condition for reliable perfusion analysis in that the arterial input is specific for each patient in the perfusion CT study of the neck at the level of common carotid artery; The results suggest that in patiets with locoregionally advanced primary laryngeal squamous cell carcinoma, the perfusion CT monitoring might be of predictive value for identifying tumors that may respond to cisplatin-based chemoradiotherapy as well as differentiating recurrent disease from nonspecific post-therapeutic changes; According to our first experience, in the cervical metastatic lymph node with primary laryngeal squamous cell carcinoma, the ADC values of them correlated with their grades. DWI using a SSEPI sequence allows reliable differentiation between benign and malignant cervical lymph nodes. But can not classified poorly differentiated metastatic nodes with primary laryngeal squamous cell carcinoma and lymphomatous nodes.