Purpose: To compare the performance of a dual-head single photon emission computed tomographic (SPECT) Anger camera operated in coincidence mode with that of a dedicated positron emission tomographic (PET) scanner in the imaging of cancer with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG).
Materials and methods: Thirty-one patients with known or suspected malignant neoplasms underwent imaging with both methods, and the images were read blindly. Diagnostic performance on a lesion-by-lesion basis was compared with attenuation-corrected PET as the standard of reference.
Results: Of a total of 109 discrete lesions depicted at PET, 60 (relative sensitivity, 55%) were identified on the coincidence-mode images. Of the nodules or masses depicted at PET, 13 (93%) of 14 lung nodules or masses, 20 (65%) of 31 mediastinal lymph nodes, five (71%) of seven lesions in the neck, five (55%) of nine axillary lymph nodes, 11 (50%) of 22 bone metastases, and six (23%) of 26 abdominal tumor deposits were correctly identified on the coincidence gamma camera images.
Conclusion: These preliminary findings indicate FDG imaging with a modified dual-detector gamma camera operating in coincidence mode can depict many of the lesions depicted with a PET scanner, particularly in the lungs. Sensitivity for lesions detected at dedicated FDG PET was poor in the abdomen and in all locations outside the lungs for tumor deposits generally less than 1.5 cm in short-axis diameter.