Table 1.

FDG PET/CT ¹ for response monitoring in immunotherapies.

Study	No. of Patients	Method of Response Assesment	Results
Sachpekidis et al. [32]	22	FDG PET/CT at baseline, after two cycles of ipilimumab and post-treatment. EORTC 2 criteria used for response classification	Early scan predictive of post-treatment response in 18 of 22 patients
Kong et al. [33]	27	FDG PET/CT after at least 12 months of treatment with pembrolizumab or nivolumab categorized as positive or negative for presence of metabolically active disease compared to response on CT at the time of the PET/CT scan	43% of patients with residual disease on CT had negative PET scans
Breki et al. [34]	31	FDG PET/CT at baseline, after two cycles of ipilimumab and post-treatment. Fractal and multifractal analysis compared to visual image assesment by nuclear medicine physicians. Seven patients excluded in comparison because of hypermetabolic lesions not related to melanoma (such as irAEs 3)	Fractal analysis results match treatment outcome in 20 out of 24 cases
Zheng et al. (Abstract) [35]	28	Retrospective study. FDG PET/CT at baseline and after 2–4 cycles of ipilimumab treatment. Response assessed according to PERCIST 4	Two-year survival rate 31% with PMD 5 and 73% with non-PMD
Fredrickson et al. (Abstract) [36]	103	Retrospective study. FDG PET/CT at baseline and after six weeks of atezolizumab treatment evaluated according to EORTC	Metabolic responders had higher overall response rate than non-responders (73.9% vs. 6.3%)

¹ Positron Emission Tomography/Computer Tomography with ¹⁸F-Fluorodeoxyglucose; ² European Organisation for Research and Treatment of Cancer; ³ Immune-related adverse events; ⁴ PET Response Criteria In Solid Tumors; ⁵ Progressive Metabolic Disease.