Preliminary Clinical Study Of ¹⁸F-FMISO Hypoxia Imaging In Nasopharyngeal Carcinoma

Objective1、To explore the identification of the hypoxia region within the primary tumor and time selection in nasopharyngeal carcinoma（NPC）¹⁸F-FMISO PET/CT imaging.2、To investigate the relationship between ¹⁸F-FMISO hypoxia image and the clinical pathological parameters of NPC.Methods1、44 NPC patients were performed with ¹⁸F-FMISO PET/CT imaging scan, and a total of 47 scans. Scan was performed at 2h and 4h after injection of ¹⁸F-FMISO respectively, images were reconstructed and merged with MRI images or CECT images, then PET/MRI or PET/CECT fusion images of nasopharyngeal were obtained, the extent of primary nasopharyngeal carcinoma lesion was determined on MRI or CECT.2、Two observers performed visual analysis and measured SUVmax of back neck muscles, nasopharyngeal primary tumor, respectively at 2h and 4h images, TMR（Nasopharyngeal primary tumor to muscle uptake ratio）was calculated.3、By Kappa test and intraclass correlation coefficient, two observers’ identify consistency of hypoxic region in nasopharyngeal primary tumor were evaluated. The image contrast of 2h and 4h was evaluated by paired rank sum test of TMR.4、The enrolled 40 patients were divided into two groups: the untreated group（13 patients）, and the treated group（27 patients, treated with docetaxel and nedaplatin）; and classification of the tumor hyphology was performed according to the WHO "The upper respiratory tract disease and ear tumor histologic classification" of 1991, nonkeratinizing（NK-NPSCC） 20 patients and keratinizing（K-NPSCC） 20 patients; of the 40 patients 39 were classifyed T stage according to Version 7 UICC staging standard nasopharyngeal carcinoma（NPC） in 2009, the number of patients with T staging 1, 2, 3 and 4 was 3, 13, 14 and 9 respectively.5、40 patients who were diagnosed as NPC were performed with¹⁸F-FMISO PET/CT. In order to compare the difference of primary tumor radioactivity uptake visual analysis and SUVmax quantitative value in the untreated group and the treated group, NK-NPSCC group and K-NPSCC group, different T staging respectively.In addition, the correlation between Primary tumor size and SUVmax quantitative value were also discussed.6、Statistical analysis was carried out on the various parameters by application software SPSS 21.0.Results1、The fusion of PET images with MRI or CECT at nasopharyngeal primary tumor were successfully completed in all cases. PET/MRI or PET/CECT can accurately show the uptaking of ¹⁸F-FMISO situation at primary nasopharyngeal carcinoma and be helpful to the quantitative determination.2、There was a high degree of consistency berween two observers wtihin the measurements of the back neck muscles and nasopharyngeal primary tumors SUVmax in 2h and 4h imaging.3、The TMR of 2h and 4h imaging were 1.56（1.22-3.32） and 1.68（1.15-4.77）respectively, and the difference was statistically significant（z=2.55,P=0.01）.4、After injection of ¹⁸F-FMISO 4h, there was no statistical significance between the groups of untreated and treated, the groups of NK-NPSCC and K-NPSCC for primary tumor radioactivity uptake visual analysis, either for SUVmax value（P>0.05）.5、Primary tumor radioactivity uptake visual analysis displayed positive correlation property with T staging, the higher the T stage, the higher the level of visual（rs =0.51, P<0.01）; different T staging SUVmax value difference was statistically significant（H=9.73,P<0.05）.6、The gross tumor volume of 39 patients with NPC was divided into two groups by the median size 26.6 mm3（>26.6mm3, ≤26.6 mm3）, the difference of SUVmax value in primary tumor between the two groups was statistically significant（t = 2.93, P< 0.01）.Conclusions1、The fusion of ¹⁸F-FMISO PET images with MRI or CECT was beneficial to accurate positioning the primary tumor of NPC and hypoxic tissue in it can be accurately identified; there was a high degree of consistency in the visual analysis and quantitative analysis of ¹⁸F-FMISO PET images in different observers; the iamge contrast of ¹⁸F-FMISO PET at 4h was superior than 2h.2、SUVmax of ¹⁸F-FMISO PET hypoxia image in NPC was associated with primary tumor size and the T stage, however, there was no obvious relation with treatment, pathological classification.