. 2020 Mar 5;12(3):601. doi: 10.3390/cancers12030601

Table 2.

Common approaches for MTV calculation with their main characteristics.

Threshold	Advantages	Disadvantages
Fixed absolute (e.g., SUV 2.5 or 4.0)	High reproducibility	Overestimation if tumor lies adjacent to areas of high physiologic uptake
Fixed absolute (e.g., SUV 2.5 or 4.0)	Observer-independence	Underestimation in tumors that have many voxels with an uptake less than the threshold
Reference regions (e.g., liver or mediastinum) *	Adjusted to patient and scan	More time-consuming
Reference regions (e.g., liver or mediastinum) *	Adjusted to patient and scan	Low availability on commercial software
Fixed relative (e.g., 41% of tumor SUVmax)	Observer-independence	Overestimation in case of low lesion-to-background ratio
Fixed relative (e.g., 41% of tumor SUVmax)	Observer-independence	Underestimation of tumors with heterogeneous uptake and high SUVmax
Adaptive (e.g., signal-to-background ratio)	Adjusted to patient and scan	More time-consuming
Adaptive (e.g., signal-to-background ratio)	Adjusted to patient and scan	Low availability on commercial software

* Thresholding method proposed by the PET Response Criteria in Solid Tumors (PERCIST) [78].