COMPARISON OF TL-201 AND F-18 FDG SPECT UPTAKE IN SQUAMOUS-CELL CARCINOMA OF THE HEAD AND NECK

PURPOSE: To compare the uptake of 2-[F-18] fluoro-2-deoxy-D-glucose (f ludeoxyglucose F-18; F-18 FDG) and thallous chloride T1 201, using sin gle-photon emission CT (SPECT), for the detection and location of squa mous cell carcinoma of the head and neck. METHODS: Five patients with biopsy-proved squamous cell carcinoma of the upper aerodigestive tract underwent both F-18 FDG and thallium-201 SPECT on the same day. F-18 FDG SPECT was performed using a dual-head gamma camera equipped with c ommercially available, extremely high-energy collimators (full width h alf-maximal height, 17 mm for 511 keV photons). Tumor size was estimat ed at 1.0 to 5.0 cm(3) in these cases. RESULTS: F-18 FDG SPECT showed five of five primary tumors. In two of the five cases, normal salivary gland activity severely limited thallium SPECT, and the tumors could not be definitively identified. Two of four lymph node groups that wer e positive for metastatic disease by CT criteria were shown by F-18 FD G SPECT. None were seen with thallium imaging. In one case, F-18 FDG S PECT was able to show a tumor that was not visible on CT. CONCLUSIONS: F-18 FDG has advantages over Tl-201 as a squamous cell carcinoma imag ing agent (primarily because of its reduced salivary activity). F-18 F DG SPECT has potential as a viable, less expensive alternative to F-18 FDG positron emission tomography. The ultimate value of F-18 FDG SPEC T imaging for detecting occult malignancy, monitoring therapeutic effe ctiveness, or evaluating tumor recurrence remains to be determined in patients with squamous cell carcinoma of the head and neck.