Purpose of the report: This study aims to determine if the expansion of a PET/CT service to include simultaneous contrast-enhanced CT with PET (PET/DCT) leads to a reduction of supplemental diagnostic CT (sCT) performed within a 6-month period centered around PET/CT for initial treatment planning of patients with head and neck cancers.
Patients and methods: There were 91 patients with head and neck cancers who had a non-contrast-enhanced PET/CT with CT (PET/aCT), and 153 patients had a PET/DCT. We compared the utilization of sCT before and after PET/aCT or PET/DCT. Logistic regression analysis, unpaired t test, and analysis of variance were performed.
Results: Among the 75 patients who had sCT scans in the 3 months before their PET/CT, 44 (58.7%) scans were performed in patients who had a PET/aCT and 31 (41.3%) scans were performed in patients who had a PET/DCT (P < 0.001). Among the 36 patients who had a CT in the 3 months after their baseline PET/CT, 23 (63.9%) were performed in patients who had a baseline PET/aCT and 13 (36.1%) were performed in patients who had a baseline PET/DCT (P < 0.001). The adjusted odds ratio for performing an sCT within 3 months before and after baseline PET/DCT scan as opposed to a PET/aCT scan was 0.24 (P < 0.001) and 0.31 (P < 0.01), respectively.
Conclusions: The opportunity to order simultaneous diagnostic CT imaging with PET/CT (PET/DCT) reduced the referrals for stand-alone CT neck imaging in the initial treatment plan of head and neck cancer patients when compared to a service that only offered the PET/CT scan with CT for attenuation correction (PET/aCT).