Predictive Role of Functional Visceral Fat Activity Assessed by Preoperative F-18 FDG PET/CT for Regional Lymph Node or Distant Metastasis in Patients with Colorectal Cancer

Abstract

ObjectivesTo investigate the role of functional visceral fat activity assessed by preoperative F-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in colorectal cancer (CRC) for predicting regional lymph node (LN) or distant metastasis.MethodWe evaluated 131 patients with newly diagnosed CRC. They all underwent pre-operative 18F-FDG PET/CT and surgery. Functional fat activity was measured by maximum standardized uptake value (SUVmax) using 18F-FDG PET/CT. Functional visceral fat activity was measured by SUVmax of visceral fat/SUVmax of subcutaneous fat (V/S) ratio. Mann-Whitney U test, χ2 test, Fisher’s exact test, receiver-operating characteristic (ROC) analysis, Spearrman’s correlation coefficient, and uni- and multivariate logistic regression statistical analyses were done.ResultsPatients with higher V/S ratio displayed a significantly higher rate of regional LN (p = 0.004) and distant metastasis (p<0.001). In addition, V/S ratio was the only factor that was significantly associated with distant metastasis. An optimal cut-off V/S ratio of 1.88 was proposed for predicting distant metastasis with a sensitivity of 84.6% and specificity of 78.8% (area under the curve: 0.86; p<0.0001)ConclusionFunctional visceral fat activity is significantly associated with distant metastasis in CRC patients. Furthermore, V/S ratio can be useful as a complementary factor in predicting distant metastasis.

Visceral adipose tissue volume and CT‐attenuation as prognostic factors in patients with head and neck cancer

“…In addition, the FDG uptake of VAT can reflect impaired metabolism of VAT in obese subjects . On the other hand, the clinical implication of the FDG uptake of adipose tissue in patients with malignant diseases has only been evaluated in a few studies, the results of which were inconsistent . In studies having patients with colorectal cancer, the FDG uptake of VAT was significantly associated with recurrence‐free survival as well as the FDG uptake of primary tumor and the presence of lymph node and distant organ metastases, showing aggressive tumor characteristics and worse survival in patients with high VAT .…”

Functional visceral fat activity evaluated by preoperative F‐18 FDG PET/CT predicts regional lymph node metastasis in differentiated thyroid cancer

“…For assessment of functional visceral fat activity, image analysis was performed as previously described. 10,11 Region of interest (ROI) was located on the targeted region. The standardized uptake (SUV) was calculated as follows:…”

Performance Evaluation of a Semi-automated Method for [18F]FDG Uptake in Abdominal Visceral Adipose Tissue

“…Because in previously studies SUV mean in VAT ranged from 0.22 to 0.89 [25,27] and SUV max from 0.53 to 1.21 [17,26], the effect of using SUV thresholds ranging from 1.0 to 2.5 on VAT and SAT uptake assessments were analyzed. In addition, the effects of different erosions ranging from 0 to 5 pixels (pixel size of 1.17 × 1.17 mm 2 ) on VAT and SAT uptake assessments were analyzed.…”

“…Imaging modalities such as magnetic resonance imaging (MRI) and X-ray computed tomography (CT) are both reliable methods for the assessment of abdominal adipose tissue volume [16] [17][18][19][20][21][22][23][24][25][26][27]. Overall, there is a growing interest in quantifying VAT as a CV risk marker and as a readout for therapeutic approaches [22,28,29].…”

“…The most common method to measure metabolic VAT activity is by manually drawing regions of interest (ROIs). However, the mean standardized uptake values (SUV mean ) in VAT measured by ROIs in different studies ranges from 0.22 to 0.88 [17,26,27] …”