Abstract:

Objective

To explore the diagnostic value of ¹⁸F-fluorodeoxyglucose （¹⁸F-FDG） positron emission tomography computed tomography （PET/CT） combined with enhanced CT in testicular malignant tumors.

Methods

A retrospective analysis was conducted on the clinical data， PET/CT and enhanced CT image results of 49 patients with testicular malignant tumors confirmed by biopsy or surgical pathology in Guangdong Provincial People′s Hospital from April 2008 to July 2020. The patients were divided into hematological testicular tumors （n=26） and non-hematological testicular tumors （n=23）. The Mann-Whitney U test was used to compare the differences in the maximum standard uptake value （SUVmax） of PET metabolic parameters and the SUVmax lesion/background ratio （SUVmax L/B） between the two groups. The chi-square test was used to compare the intergroup differences in enhanced CT features between patients with seminoma and those without seminoma.

Results

Among the 49 patients， the SUVmax level of patients with hematological systemic tumors was higher than that of patients with non-hematological tumors ［9.2（6.9，13.4），7.8（4.8，9.1）］， and the difference was statistically significant （Z=-2.02， P＜0.05）；SUVmax L/B values were ［3.5（1.9， 6.1）， 2.5（1.7， 3.1）］， there was no statistically significant difference （Z=-0.71， P＞0.05）. CT enhancement in 26 cases of hematological testicular tumors and 11 cases of seminoma showed uniform enhancement， no necrosis， clear boundaries， and varying degrees of increased FDG metabolism. CT enhancement in 12 cases of non-seminoma showed significantly heterogeneous enhancement， necrosis， unclear boundaries， and slightly increased FDG metabolism. The enhanced CT features of seminoma and non-seminoma were compared. There were statistically significant differences in the degree of the enhancement degrees ［6 cases （mild）， 4 cases （moderate）， 1 case （obvious）；0 case（mild）， 4 cases （moderate）， and 8 cases （obvious）， respectively］， necrosis （3 cases， 10 cases）， and unclear boundaries （0 cases， 5 cases） （χ²=11.42， 5.32， 11.24，all P＜0.05）. The SUVmax and SUVmax L/B of the two groups of patients were compared， and the differences were not statistically significant（Z=0.77， -0.92， all P＞0.05）. Among the 49 patients， 11 cases were in stage Ⅰ， 19 cases in stage Ⅱ，6 cases in stage Ⅲ， and 13 cases in stage Ⅳ.

Conclusion

¹⁸F-FDG PET/CT combined with contrastenhanced CT has high value in the diagnosis， differential diagnosis， and staging of testicular malignant tumors.

Key words: Testicular neoplasms, Positron-emission tomography, ¹⁸F-fluorode-oxyglucose, Contrast-enhanced CT