Optimization of Contrast Agent Dose in CT With Lean Body Weight

Study Overview
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Brief Summary
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This study evaluates the different enhancement using a contrast agent dose in computed tomography based on total body weight or based on lean body weight. Half of participants will receive contrast agent dose based on their total body weight, while the other half will receive a dose based on their lean body weight. Our hypothesis is that if contrast agent is administered not basing on total body weight but on lean body weight it is possible to obtain equal or better quality of enhanced images, a reduction of the variability of contrast enhancement, and also a dose reduction in some patients (overweight ones).

Detailed Description
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Patients will undergo a CT scan of abdomen (multi-phasic) with contrast agent and will be measured: total body weight (TBW), height, lean body weight (LBW) and body mass index (BMI) through formulas known in literature and with a balance for bioelectrical impedance analysis. There is no administration of drugs other than those indicated in the request of the treating physician. Contrast agent dose: IOPAMIRO® (Iopamidol) is an x-ray contrast medium of the new generation of non-ionic compounds, which are watersoluble because the molecular structure incorporates hydrophilic groups. Recommended dosage (ml) is 0.5-2.0/kg. Single injection volume depends on the vascular area to be examined. IOMERON® (Iomeprolo) is an x-ray contrast medium of the new generation of non-ionic compounds, which are watersoluble because the molecular structure incorporates hydrophilic groups. Recommended dosage (ml) is 0.5-2.0/kg. Single injection volume depends on the vascular area to be examined. Patients will be randomly assigned to undergo one of the two contrast agent protocols. Control group (TBW protocol): patients will receive a contrast agent dose based on their TBW as a standard clinic protocol with a dose of 0.40 gI/kg of TBW. There are no differences compared to clinical practice. Experimental group (LBW protocol): patients will receive a contrast agent dose based on their calculated LBW to test our hypothesis with a dose of 0.65 gI/kg of LBW, derived from our pilot study (LBW_01 approved 10/11/2016, registration number 160/int/2016). If radiologists prefer a more enhanced examination, only scanning with contrast agent will be repeated with the standard dose as the standard clinical protocol.

Official Title
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Randomized Controlled Trial of Optimization of Contrast Agent Dose in CT With Lean Body Weight

Conditions
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Contrast Agent With Lean Body Weight

Intervention / Treatment
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* Drug: Iopamidol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient ≥ 18 years of age; Patients who will perform a contrast-enhanced abdominal CT multi-phasic in our institutions; Patients able to give informed consent. Exclusion Criteria: history of chronic underlying liver disease (cirrhosis, fatty infiltration of the liver, or glycogen storage disease); history of chronic underlying heart disease (congestive heart failure, prior cardiac valve replacement, restrictive and/or constrictive pericarditis); multiple myeloma; hypersensitivity to iodine-containing compounds; renal insufficiency (serum creatinine level ≤ 1.8 mg/dL [159.12 µmol/L]) or patients with renal failure (eGR <30 ml/min/1.73 m2); patients with antecubital vein that, at medical evaluation, cannot sustain the flow rate of CA injection (see below); patients carrier of prosthesis or metal bullets, pacemaker or stimulators; patients with liver diseases that affect the entire parenchyma; fragile patients which, after radiologist evaluation, require lower dose of CA; pregnancy; general contraindications to CT examination or reasoned decision of the radiologist.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study design is monocentric, comparative, randomized, double blinded. Patients will undergo a CT scan of abdomen (multi-phasic) with contrast agent and will be measured: TBW, height, LBW and body mass index (BMI) through formulas known in literature and with a balance for bioelectrical impedance analysis. There is no administration of drugs other than indicated in the request of the treating physician.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: TBW protocol<br>Patients will receive a contrast agent dose based on their TBW as a standard clinic protocol. | Drug: Iopamidol<br>* Contrast agent will be adrministered intravenously using total body weight or lean body weight, calculated with bioelectrical impedance analysis balance.<br>* Other names: Iomeprolo;|
| Experimental: LBW protocol<br>Patients will receive a contrast agent dose based on their calculated LBW. | Drug: Iopamidol<br>* Contrast agent will be adrministered intravenously using total body weight or lean body weight, calculated with bioelectrical impedance analysis balance.<br>* Other names: Iomeprolo;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Contrast Enhancement | The liver contrast enhancement (ΔCEL) will be calculated as the difference between the CT value measured in the venous phase and that measured before contrast injection. | 1 day |