Association between body mass index and hepatic 18F-FDG standardised uptake value (SUV) in patients undergoing PET-CT scan

Abstract

Objectives: The study aims to measure the amount of radiopharmaceutical absorbed by a normal liver compared with a patient with liver cancer and to examine the effect of BMI on radiopharmaceutical absorption.

Method: The Study assessed75 males (40 patients and 35 normal) and 75 females (40 patients and 35 normal), aged between 31 and 75, with body weights ranging from 50 to 100 kg and heights ranging from 150 cm to 180 cm. Patients with a fasting blood sugar content exceeding 200 mg/dL were excluded.

Results: Differences (P ˂ 0.001) were reported in the mean SUVs between the participants with normal livers and those with liver cancer of the same BMI, where, the average SUV was greater with liver cancer in the underweight, normal weight, overweight, and obese BMI categories, with kg/m² of 141%, 160%, 197%, and 253%, respectively. Furthermore, highly significant differences (P ˂ 0.01) were found for the mean SUVs between the normal body weight and other BMI categories.

Conclusion: Our study suggests that the administration of FDG based on body weight can result in underestimation, which may lead to small, dormant tumours being overlooked. An overestimation could lead to unnecessary wastage of radioactive materials and increase the risk of harmful exposure for the participant. Caution is advised regarding greater amounts of fat tissue in overweight subjects when compared with those of normal weight; the former require a greater dose of FDG than the latter, leading to greater absorption of FDG with glucose by cancerous cells.