Prospective Comparison of 99mTc-GH SPECT/CT and 18F-FDOPA PET/CT for Detection of Recurrent Glioma A Pilot Study

Objective: This study aimed to evaluate and compare the role of Tc-99m-GH SPECT/CT and F-18-FDOPA PET/CT for diagnosing recurrence in patients with glioma. Methods: Thirty patients with histopathologically proven glioma (glioblastoma multiforme, 14; grade III, 6; grade II, 8; and grade I, 2), who presented with clinical and/or imaging suspicion of recurrence were prospectively evaluated. They were primarily treated with surgery and radiotherapy with or without chemotherapy. Each patient underwent Tc-99m-GH SPECT/CT and F-18-FDOPA PET/CT within a span of 15 days. Images were evaluated qualitatively and quantitatively by 2 experienced nuclear medicine physicians in consensus. Histopathology and/or clinical/imaging follow-up were used as reference standard. Results: Based on reference standard, 22 patients were positive and 8 were negative for recurrence. Tc-99m-GH SPECT/CT was positive for recurrence in 22 and negative in 8 patients. F-18-FDOPA PET/CT scan was positive for recurrence in 23 and negative in 7 patients. Sensitivity, specificity, and accuracy were 86.4%, 62.5%, and 80% for Tc-99m-GH SPECT/CT and 100%, 87.5%, and 96% for F-18-FDOPA PET/CT, respectively. No significant difference was found between Tc-99m-GH SPECT/CT and F-18-FDOPA PET/CT overall (P = 1.00), as well as for low-grade (P = 0.250) or high-grade tumors (P = 0.50). Significant correlation was noted between tumor-brain of Tc-99m-GH with both tumor-striatum (r = 0.371; P = 0.044) and tumor-cerebellum ratio of F-18-FDOPA (r = 0.369; P = 0.045). Conclusions: For detection of recurrence in glioma patients, Tc-99m-GH SPECT/CT is not inferior to F-18-FDOPA PET/CT and can be used as a low-cost alternative.