Table 1 Key points to consider during [¹⁸F]FDG PET/CT procedure and reporting

Protocol/procedure

The skull base should be included in the imaging field-of-view to evaluate possible immune-related hypophysitis.

Whole-body imaging from the vertex to the feet is recommended in neoplasia with tendency to extensive metastatic disease (e.g., melanoma, Merkel cell tumor, etc.).

EANM guideline [10] and SNMMI procedure standards for tumor imaging [11].

The RSNA QIBA FDG/CT guidance [12] and specific radiologic society guidelines for contrast-enhancement [¹⁸F]FDG PET/CT [13]

International harmonizing standards, i.e. EANM/EARL program [10, 14].

Reporting/documentation

Type and number of cycles of immunotherapy must be specified.

Target lesions and response pattern to be reported based on the chosen metabolic response criteria, which should be recorded [4,5,6,7,8,9]. Quantitation of metabolic tumor burden is recommended.

Comparison with relevant morphologic findings on CT, and request for confirmatory scanning in case of suspected progression.

Appearance, extent, severity, and variation over time of the irAEs and other signs of immune activation must be reported.