Published online Jun 28, 2019. doi: 10.4329/wjr.v11.i6.81
Peer-review started: March 11, 2019
First decision: April 16, 2019
Revised: May 11, 2019
Accepted: June 20, 2019
Article in press: June 21, 2019
Published online: June 28, 2019
18-F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is increasingly used for staging and monitoring of many common malignancies. Classical “do not touch” and benign bone lesions are sometimes detected in 18F-FDG PET/CT studies. These lesions may be referred for biopsy because the PET/CT interpreting physician may be unfamiliar with the spectrum of the 18F-FDG PET/CT uptake pattern exhibited by these lesions.
There is no descriptive analysis of 18F-FDG uptake of “do not touch” and benign osseous lesions.
This study evaluates the spectrum of 18F-FDG PET/CT uptake patterns in several “do not touch” and benign osseous lesions to provide a reference for physicians interpreting 18F-FDG PET/CTs .
This study evaluated 287 independent patients, of whom 287 were classic “do not touch” (benign cystic lesions, insufficiency fractures, bone islands, bone infarcts) or benign osseous lesions (hemangiomas, enchondromas, osteochondromas, fibrous dysplasia, Paget’s disease, osteomyelitis) 18F-FDG PET/CT from January 1, 2006 to December 1, 2018 at a single academic institution. The maximum and mean standardized uptake values (SUV), and the ratio of the maximum SUV to mean blood pool were calculated. Pearson’s correlations between lesion size and maximum SUV were calculated.
The maximum SUV range was as follows: hemangiomas (0.95-2.99), bone infarcts (0.37-3.44), bone islands (0.26-3.29), enchondromas (0.46-2.69), fibrous dysplasia (0.78-18.63), osteochondromas (1.11-2.56), Paget’s disease of bone (0.93-5.65), insufficiency fractures (1.06-12.97) and for osteomyelitis (2.57-12.64). The upper range of the maximum SUV was lowest for Osteochondromas (maximum SUV 2.56). The upper range of the maximum SUV was highest for fibrous dysplasia (maximum SUV of 18.63). In each lesion type, at least one lesion showed greater 18F-FDG activity than the blood pool, with the highest maximum SUV up to 9.34 times the blood pool average (osteomyelitis) to the blood pool average (hemangioma) 1.42 times. Except for enchondromas, there was no correlation between the maximum SUV and the size of the lesion. Larger enchondromas have a higher maximum SUV (r = 0.36, P = 0.02).
“Do not touch” and benign osseous lesions may exhibit 18F-FDG uptake higher than in the blood pool on PET/CT. Therefore, 18F-FDG uptake above blood pool should not be misunderstood to indicate the presence of malignancy. The CT appearance, if pathognomic should be used to guide management rather than the maximum SUV.
The data comes from an academic tertiary health care center that primarily treats adult patients. More common lesions in the pediatric population, including cortical desmoids and avulsion fractures, were not described. Although SUV measurements were normalized by weight, acquisition time and injection dose, they may be affected by factors such as body mass index, scanner calibration and imaging artifacts.