TITLE:
Metrics to Evaluate PET Response to Therapy Based on 3D Analysis
AUTHORS:
Michael L. Goris, Hongyun J. Zhu
KEYWORDS:
Metrics, PET Response, 3D
JOURNAL NAME:
Open Journal of Medical Imaging,
Vol.10 No.3,
August
28,
2020
ABSTRACT: The
disadvantage of visualizing tomography by slices is that an important attribute
of the object, its volume, is not easily perceived or measured. In oncology
this creates a problem, which is addressed here: if early detection and
response to treatment are an important prognostic element, then volume is important.
The literature has proposed surrogates to volume derived from measures on
slices, but geometrically they are not well founded. Actual volume analysis is
not complex, and the proposed method applies equally well to organs as to
tumors. Volume based measures are more sensitive than individual SUV values, of
which the commonly most used is the maximum Standardized Uptake Value (SUVm). If the tumor volume is
defined, it can be replaced by the total tumor SUV (SUVt). If the
metric for change is the ratio after/(before + after), in the patient
population analyzed here, the SUVm metric averages 0.132 for
response and 0.662 for progression, the total SUVt range is 0.069 to
0.734. In contrast to SUVt, SUVm is based on a weak
sampling method since it is based on the value of a single voxel of more than
10 million.