Restaging and Follow up of Seminomatous and Non Seminomatous Testicular Tumors Using F18 FDG PET/CT.

Aim: to evaluate the role of FDG PET/CT in restaging and follow up of Seminomatous and non Seminomatous testicular tumors. Materials and methods: 54 patients (mean age: 34.2 ±11.8) with pathologically proven testicular cancer in whom FDG PET/CT were retrospectively assessed. Total 89 PET/CT studies were conducted in comparison to diagnostic CT. Pathological and clinical/radiological follow-up for 6-15 months duration served as standards of reference. Results: Seminomas type was more prevalent (64.8%). 30% of patients did not develop metastases during their course of disease. While 38 patients develop metastatic lesions (31 had abdominal nodal deposits and 5 patients had distant sites and 2 patients presented by both).The lung was the most common site for distant metastases. All 33 patients with recurrent lesions had regional abdominal nodal deposits, while distant metastasis was more detected in 9 patients with Non Seminomatous pathology. FDG PET/CT had higher sensitivity, specificity, and accuracy of 94%, 86.5%, and 92.5% versus 76%, 85% 83%; for diagnostic CT in per patients analysis. A total of 90 lesions were reported, (62 nodal & 28 distant) metastatic lesions were analyzed. PET/CT showed good accuracy for the detection of residual/recurrent Seminomatus lesions, with an overall sensitivity and specificity of 94.7 % and 93.3 %, respectively compared to 89.2% and 56.2% for diagnostic CT, their size mean + SD (3.9+-3.1) and SUV max (7+-6.3).Non Seminomatus distant metastases showed comparable results for both PET/CT and diagnostic CT with false negative results in small sized (mainly lung lesions). 25 patients had single PET/CT; its results with diagnostic CT were comparable in 20 patients (84%), while 29 patients with repeated 64 PET/CT studies had comparable analysis to diagnostic CT in 22 patients (~76%). In the other 7 patients (~24%), a higher value of PET/CTin assessment of therapy response was noted. PET/CT shows CMR in 5 patients that remain stationary in CT based on size difference analysis. Conclusion: The current study showed that 18FDG-PET/CT is useful in re-staging & assessment of response on patients with Germ cell testicular tumor as compared to CT regarding Seminomatous abdominal nodal lesions and non Seminomatous distant disease.