Tumor volume-adapted SUVN as an alternative to SUVpeak for quantification of small lesions in PET/CT imaging: a proof-of-concept study

• Published in: Japanese journal of radiology Vol. 39; no. 8; pp. 811 - 823
• Main Authors: Mosleh-Shirazi, Mohammad Amin, Nasiri-Feshani, Zahra, Ghafarian, Pardis, Alavi, Mehrosadat, Haddadi, Gholamhasan, Ketabi, Ali
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01-08-2021; Springer Nature B.V
• Subjects: Algorithms; Computed tomography; Image reconstruction; Imaging; Inserts; Lesions; Medicine; Medicine & Public Health; Noise; Nuclear Medicine; Original Article; Positron emission; Radiology; Radiotherapy; Recovery; Reproducibility; Scanners; Tomography; Tumors; FDG-PET/CT; Small lesions; SUV; Uptake quantification; Image reconstruction
• ISSN: 1867-1071; 1867-108X
• DOI: 10.1007/s11604-021-01112-w

Purpose
SUV
peak
is a recommended quantification metric except for small lesions. We aimed to assess the averaged standard uptake value (SUV
N
) as an alternative to SUV
peak
for small-lesion quantification.
Materials and methods
NEMA-like phantom images were reconstructed using OSEM, OSEM + PSF, OSEM + TOF and OSEM + TOF + PSF with two post-smoothing Gaussian filters for different background activity levels. SUV
max
, SUV
N
(
N
 = 5, 10, 15, 20, 25, 30, 35 or 40 hottest voxels), and SUV
peak
, relative percent error, contrast recovery, and volume recovery coefficients were quantified and assessed.
Results
SUV
N
did not have the limitations of SUV
peak
for smaller lesions. In the smallest insert at 2.68 kBq/ml, optimum
N
values for OSEM, OSEM + PSF, OSEM + TOF and OSEM + TOF + PSF were 10, 5, 15, and 10 for SUV
N
, respectively. The same
N
values were obtained for metabolic tumor volumes (MTVs) for all reconstruction algorithms. At 5.30 kBq/ml,
N 
= 5 was optimum for SUV
N
and MTVs. For the larger inserts, the optimum
N
increased and tended towards the maximum (similar to SUV
peak
).
Conclusions
SUV
N
is more accurate than SUV
max
or SUV
peak
for small lesions, while being as accurate in larger ones. This harmonizing capacity of SUV
N
can be beneficial for the quantitative analysis of small tumor volumes.