Purpose or Case Report: In the background of this limited data, this study aims to analyze and compare the size significance of right iliac fossa lymph nodes in pediatric patients in relation to metabolic activity on (18F-FDG PET/CT), scan in tertiary center managing oncological and non-oncological cases.
Methods & Materials: It is a retrospective study done on a tertiary hospital dealing with oncological and non-oncological cases from 2016 to 2020. The inclusion criteria included patients aged from 0 to 16 years who underwent contrast-enhanced abdominal CT and (18F-FDG PET/CT) scans with intervals less than 3 days between both scans which allow comparison of right iliac fossa lymph nodes in terms of the short and long axes on computed tomography scan in relation to metabolic activity on in terms of standardized uptake value (SUV) in PET/CT Scan. Exclusion criteria are patients who presented as initial presentation, had right iliac fossa mass or pelvic mass reaching the right iliac fossa, right iliac fossa surgery, patients pre or post-radiotherapy or post-chemotherapy, patients who had treatment between the interval of both scans, or subjects who had both scans more than 3 days in interval.
Results: 128 out of 350 subjects were fitting the inclusion criteria. Those subjects showed means measurement of the right iliac fossa lymph node on the short axis and long axis were 0.628 and 1.0082 millimeter (mm) respectively. The highest sensitivity and specificity value of short-axis measurement was at (≥ 7 mm) with a diagnostic accuracy of 0.930. The highest sensitivity and specificity value of long axis measurement were at (≥ 11 to 12 mm) with a diagnostic accuracy of 0.897.
Conclusions: Measurement of the lymph node on the right iliac fossa in the short axis exceeding 7 mm is our conclusion to call this lymph node is abnormal warranting further management according to our criteria correlated with CT and CT/PET correlation. A lymph node measuring 7 mm or less is considered nonspecific and non-pathological. Therefore, it might be a more appropriate definition of the abnormal right iliac fossa lymph node.