Role of FDG-PET in the diagnosis of recurrent and metastatic lesions of malignant testicular tumors

Abstract

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Objectives: The aim of this study was to determine the role of FDG-PET in the management of patients with testicular cancer and rising tumor markers or with suspicious radiological and clinical findings for recurrent and metastasis during the follow-up period. Methods: Fifty-six FDG-PET studies of 41 patients (mean age: 40±14) diagnosed with primary testicular cancer (32 seminomas, 7 non-seminomatous, 2 lymphomas) were retrospectively analyzed. PET scan was requested because of a suspicion for recurrence and or distant metastasis based on results of tumor markers (ALP, HCG and LDH) and or radiological (CT/MRI) findings. Results: The FDG-PET and radiological imaging results are presented in the table. Although CT/MRI showed enlarged lymph nodes and distant metastatic lesions on 12 studies, FDG-PET showed no abnormally increased uptake in these sites and therefore suggestive of inactive disease. PET and radiological methods were both false positive in two patients among 56 studies. PET was false negative for one metastatic cystic teratoma lesion and was false positive for one patient with benign lung lesions. CT/MRI was false negative for one patient with bone marrow metastasis which was detected by PET. Conclusions: These data demonstrate that FDG-PET is superior technique to radiological methods in detecting lymph node and distant metastases in patients with testicular cancer during follow up period after therapy. In addition, PET may also prove to be a useful technique for the assessment of therapy response in these patients. Therefore, routine use of this imaging modality is justified in this setting.