Detection of distant metastases and distant second primary cancers in head and neck squamous cell carcinoma: comparison of [18F]FDG PET/MRI and [18F]FDG PET/CT

Insights into Imaging

Table 2 SUVmean and SUVmax values of distant lesions with focal [¹⁸F]FDG uptake as measured on PET/MRI and PET/CT and p values of statistical comparisons between benign and malignant lesions

	Total number of lesions with focal uptake n = 117	Total number of benign lesions with focal uptake n = 35	Total number of malignant lesions with focal uptake n = 82	p value
Number of focal uptake lesions detected on PET/MRI	113	32	81
SUVmean PET/MRI	2.1 [1.3–3.3]	1.6 [0.9–2.5]	2.3 [1.4–3.6]	0.006
SUVmax PET/MRI	3.1 [1.8–5.1]	2.1 [1.5–3.4]	3.4 [1.9–5.8]	0.003
Number of focal uptake lesions detected on PET/CT	108	32	76
SUVmean PET/CT	2.2 [1.5–3.2]	2.0 [0.8–2.7]	2.3 [1.6–3.9]	0.003
SUVmax PET/CT	3.4 [2.1–5.1]	2.8 [1.3–3.6]	3.7 [2.1–7.2]	< 0.001

Median values and interquartile intervals are presented. Among the 117 lesions with focal uptake, 104 were detected by the two readers on both modalities, 9 only on PET/MRI and 4 only on PET/CT. Four focal uptake lesions (3 benign and 1 malignant) were missed on PET/MRI, and 9 focal uptake lesions (3 benign and 6 malignant) were missed on PET/CT