Lean body weight versus total body weight to calculate the iodinated contrast media volume in abdominal CT: a randomised controlled trial

Moreno Zanardo,Giovanni Di Leo,Nicol Antonina Rita Panarisi,Francesco Sardanelli,Caterina Beatrice Monti,Fabio Martino Doniselli,Anastassia Esseridou,Massimiliano Agrò

doi:10.1186/s13244-020-00920-4

Abstract

ObjectivesIodinated contrast media (ICM) could be more appropriately dosed on patient lean body weight (LBW) than on total body weight (TBW).MethodsAfter Ethics Committee approval, trial registration NCT03384979, patients aged ≥ 18 years scheduled for multiphasic abdominal CT were randomised for ICM dose to LBW group (0.63 gI/kg of LBW) or TBW group (0.44 gI/kg of TBW). Abdominal 64-row CT was performed using 120 kVp, 100–200 mAs, rotation time 0.5 s, pitch 1, Iopamidol (370 mgI/mL), and flow rate 3 mL/s. Levene, Mann–Whitney U, and χ2 tests were used. The primary endpoint was liver contrast enhancement (LCE).ResultsOf 335 enrolled patients, 17 were screening failures; 44 dropped out after randomisation; 274 patients were analysed (133 LBW group, 141 TBW group). The median age of LBW group (66 years) was slightly lower than that of TBW group (70 years). Although the median ICM-injected volume was comparable between groups, its variability was larger in the former (interquartile range 27 mL versus 21 mL, p = 0.01). The same was for unenhanced liver density (IQR 10 versus 7 HU) (p = 0.02). Median LCE was 40 (35–46) HU in the LBW group and 40 (35–44) HU in the TBW group, without significant difference for median (p = 0.41) and variability (p = 0.23). Suboptimal LCE (< 40 HU) was found in 64/133 (48%) patients in the LBW group and 69/141 (49%) in the TBW group, but no examination needed repeating.ConclusionsThe calculation of the ICM volume to be administered for abdominal CT based on the LBW does not imply a more consistent LCE.

Highlights

In the current clinical context, where personalised approaches to patient care have become increasingly important, research on iodinated contrast media (ICM) dose optimisation is a relevant issue [1, 2]
This randomised controlled trial (RCT) was approved by the local Ethics Committee (IRCCS San Raffaele Hospital, authorisation number 160/int/2017) and was performed in a university hospital that is partially supported by the Italian Ministry. These two dosages were obtained on the basis of the data reported in a retrospective study on 201 patients [35]. The former represented the mean ICM dose used in our Institution for abdominal computed tomography (CT), while the second was the equivalent dose expressed in terms of lean body weight (LBW) that allowed to reach the same liver contrast enhancement (CE) as that obtained using total body weight (TBW)
Thereafter, 8 patients randomised to the LBW group and 9 randomised to the TBW group were dropped out as the intended ICM dose was deemed too low (n = 10) or too high (n = 7) by the radiologist

Summary

Introduction

In the current clinical context, where personalised approaches to patient care have become increasingly important, research on iodinated contrast media (ICM) dose optimisation is a relevant issue [1, 2]. It is widely accepted that a larger patient needs a higher iodine load to achieve the same CE compared to a smaller patient. For this reason, dosing ICM on patient total body weight (TBW) instead of using a fixed ICM volume, which, is still usual practice somewhere [10], may be regarded as better [11,12,13,14,15,16,17]

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