Article Figures & Data
Figures
- FIGURE 1.
Patients from normal-weight subgroup. (A) Control-group patient 57 kg in weight, 1.69 m in height (BMI, 19.96), and injected with 272.69 MBq of 18F-FDG was scored 1 for image quality control. (B) Treatment-group patient 56 kg in weight, 1.68 m in height (BMI, 19.84), and injected with 190 MBq of 18F-FDG was scored 1 for image quality control.
- FIGURE 2.
Patients from obese subgroup. (A) Control-group patient 80 kg in weight, 1.59 m in height (BMI, 31.64), and injected with 298.22 MBq of 18F-FDG was scored 3 for image quality control. Activity is seen in soft tissues, and PET image has poor signal-to-noise ratio. (B) Treatment-group patient 82 kg in weight, 1.63 m in height (BMI, 30.86), and injected with 223.11 MBq of 18F-FDG was scored 1 for image quality control. Neither patient was diabetic.
- FIGURE 3.
(A) Volume ionization chamber (RAM ION) used in this project. (B) Identification tag and personal whole-body, wrist, and ring dosimeters assigned to department personnel to measure accumulated effective dose. (C) Proper positioning of wrist and ring dosimeters.
- FIGURE 4.
Summary of dose rate emitted by patients after 18F-FDG injection. Arrows show decreased dose rate in treatment group when doses were administered according to BMI.
- FIGURE 5.
Comparative curves of administered doses of 18F-FDG (MBq) related to BMI in control group (dashed line) and treatment group (□), as well as in theoretic control group (♦) in which highest margins were applied in compliance with international guidelines.
- FIGURE 6.
(Left) 18F-FDG doses administered to 3 patients with same weight according to current international guidelines. (Right) 18F-FDG doses adjusted on the basis of BMI (Table 1).
Tables
BMI Lower limit Upper limit Dose 15 164.65 167.24 164.65 16 169.09 171.68 170.57 17 174.64 177.23 176.12 18 179.82 182.41 178.30 19 185.00 187.59 186.48 20 192.03 194.62 193.51 21 194.25 196.84 195.73 22 200.91 203.50 202.39 23 207.57 210.16 209.05 24 213.86 216.45 215.34 25 220.15 222.74 221.63 26 223.85 229.03 224.59 27 222.00 224.59 223.48 28 222.74 225.33 224.22 29 223.48 226.07 224.96 30 226.44 229.03 227.92 31 229.40 232.36 230.88 32 231.99 234.58 233.47 33 237.17 239.39 238.28 34 239.76 241.98 240.87 35 246.79 249.01 247.90 36 251.23 253.82 252.71 37 256.04 258.26 257.15 38 262.70 265.29 264.18 39 269.70 267.10 268.43 40 274.17 271.58 272.87 41 280.83 278.24 279.53 42 285.27 282.68 283.97 Treatment group (MBq/BMI) Control group (MBq/kg) Score Score Group No. of patients Average BMI Average dose (MBq) 1 2 3 No. of patients Average BMI Average dose (MBq) 1 2 3 Underweight 5 16.6 194 4 1 0 5 16.5 245 4 1 0 Normal weight 75 22.8 215 45 25 5 73 22.6 275 26 33 14 Overweight 74 27.0 224 49 18 7 74 27.0 286 28 22 24 Obese 25 33.0 240 18 3 4 26 32.8 294 9 5 12 Morbidly obese 1 41.5 284 1 0 0 2 45.5 313 0 0 2 Total 180 6.85–11.1 MBq/BMI 117 47 16 180 5.55–7.4 MBq/kg 67 61 52 - TABLE 3
Interobserver Correlation Coefficient (ICC), 95% Confidence Interval (CI), and Level of Significance
Group ICC 95% CI P Underweight 0.99 0.98–0.99 <0.001 Normal weight 0.97 0.92–0.99 <0.001 Overweight 0.95 0.94–0.99 <0.001 Obese 0.98 0.97–0.99 <0.001 Morbidly obese 0.99 0.98–0.99 <0.001
