Detection of recurrent nasopharyngeal carcinomas after radiotherapy with technetium-99m tetrofosmin single photon emission computed tomography in patients with indeterminate magnetic resonance imaging findings.

The aim of this study is to evaluate the effectiveness of technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) of head and neck for detecting suspected recurrence of nasopharyngeal carcinomas (NPCs) when magnetic resonance imaging (MRI) findings are indeterminate. MRI was performed 4 months after radiotherapy and 26 NPC patients with indeterminate MRI findings were included. MRI, Tc-99m TF SPECT, and biopsy were performed within 1 week. The final results were based on histopathologic findings and clinical follow-up for at least 6 months. For detecting recurrent NPC in indeterminate MRI findings, the sensitivity, specificity, and accuracy of Tc-99m TF SPECT were 92.3%, 100.0%, and 96.2%, respectively. Based on this result, we can suggest Tc-99m TF SPECT is effective to detect recurrent NPC when MRI findings are indeterminate. However, further studies including a larger NPC patient population are warranted to determine the exact role and clinical usefulness of Tc-99m TF SPECT to differentiate benign lesions and recurrent NPC when MRI findings are indeterminate.

Usefulness of (18)F-fluorodeoxyglucose positron emission tomography to detect para-aortic lymph nodal metastasis in advanced cervical cancer with negative computed tomography findings.

OBJECTIVE: In advanced cervical cancer, it has been reported that progression-free survival is significantly related to para-aortic lymph node metastasis. Computed tomography (CT) has been widely used for clinical staging, but its sensitivity for lymph nodal metastasis is low. Therefore, this prospective study was undertaken to evaluate (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting para-aortic lymph nodal metastasis in patients with locally advanced cervical carcinoma when CT findings were negative. METHODS: Fifty women with advanced cervical cancer confined to the pelvis with negative abdominal CT findings were included in this study. After 10 mCi of FDG was administered intravenously, the abdomens were scanned by PET. Para-aortic lymph node metastases were diagnosed as present or absent according to a standardized staging procedure. RESULTS: Retroperitoneal surgical exploration revealed 14 patients with para-aortic lymph nodal metastasis. Two patients had false-negative FDG-PET findings and the other two patients had false-positive FDG-PET findings. CONCLUSION: Overall, FDG-PET imaging had a sensitivity of 85.7%, a specificity of 94.4%, and an accuracy of 92%. When abdominal CT findings are negative, the use of FDG-PET can accurately detect para-aortic lymph nodal metastatis in patients with advanced cervical cancer.