Digital versus analog PET/CT in patients with known or suspected liver metastases

Aim To assess if digital PET/CT improves liver lesion detectability compared to analog PET/CT in patients with known or suspected liver metastases. Materials and methods We prospectively included 83 cancer patients, with one or more of these conditions: history of liver metastases, clinical risk of having liver metastases or presence of suspected liver metastases on the first of the two PET/CTs. All patients were consecutively scanned on each PET/CT on the same day after a single [F-18]fluorodeoxyglucose dose injection. The order of acquisition was randomly assigned. Three nuclear medicine physicians assessed both PET/CTs by counting the foci of high uptake suspicious of liver metastases. Findings were correlated with appropriate reference standards; 19 patients were excluded from the analysis due to insufficient lesion nature confirmation. The final sample consisted of 64 patients (34 women, mean age 68 +/- 12 years). Results As per-patient analysis, the mean number of liver lesions detected by the digital PET/CT (3.84 +/- 4.25) was significantly higher than that detected by the analog PET/CT (2.91 +/- 3.31); P < 0.001. Fifty-five patients had a positive PET/CT study for liver lesions. In 26/55 patients (47%), the digital PET/CT detected more lesions; 7/26 patients (27%) had detectable lesions only by the digital system and had Conclusion Digital PET/CT offers improved detectability of liver lesions over the analog PET/CT in patients with known or suspected liver metastases.

Automated summary

Digital PET/CT offers improved detectability of liver lesions over analog PET/CT in patients with known or suspected liver metastases, detecting a significantly higher number of liver lesions and being able to detect additional lesions that the analog system missed.