Adult Patients
The recommended intravenous dose range for adult patients for lung imaging is 37 MBq to 148 MBq (1 mCi to 4 mCi) and 200,000 to 700,000 particles of Technetium Tc 99m Albumin Aggregated Injection after preparation with oxidant-free Sodium Pertechnetate Tc 99m Injection.
The recommended intraperitoneal dosage range for adult patients for peritoneovenous shunt patency evaluation is 37 MBq to 111 MBq (1 mCi to 3 mCi) and 200,000 to 700,000 particles. Adequate measures should be taken to assure uniform mixing with peritoneal fluid. Serial images of both the shunt and target organ should be obtained and correlated with other clinical findings. Alternatively, the drug may be administered by percutaneous transtubal injection. The recommended percutaneous transtubal dosage range for adult patients is 12 MBq to 37 MBq (0.3 mCi to 1 mCi) in a volume not to exceed 0.5 mL.
The recommended range of particle numbers per single injection is 200,000 to 700,000 with the recommended number of approximately 350,000. Depending on the activity added and volume of the final reconstituted product, the volume of the dose may vary from 0.2 mL to 1.9 mL.
The number of particles available per dose of Technetium Tc 99m Albumin Aggregated Injection will vary depending on the physical decay of technetium Tc 99m that has occurred. The number of particles in any dose and volume to be administrated may be calculated as follows:
Where:
VTc = volume of solution added to reaction vial
D = desired dose to be administered in MBq (mCi)
C = concentration at calibration time of Sodium Pertechnetate solution to be added to the reaction vial in MBq/mL (mCi/mL)
Va = volume to be administered in mL
P = number of particles in dose to be administered
Fr = fraction of Technetium Tc 99m remaining after the time of calibration (Table 7)
N = number of particles per vial. The number of particles per vial for the lot is located on the vial label.
Pediatric Patients
In pediatric patients, the recommended intravenous dose for perfusion lung imaging is in the range of 0.925 MBq/kg to 1.85 MBq/kg (0.025 mCi/kg to 0.05 mCi/kg) of body weight; a usual dose is 1.11 MBq/kg (0.03 mCi/kg), except in newborns, in whom the administered dose should be 7.4 MBq to 18.5 MBq (0.2 mCi to 0.5 mCi). Not less than the minimum dose of 7.4 MBq (0.2 mCi) should be employed for this procedure. The number of particles varies with age and weight as shown in Table 1.
Table 1 – Pediatric Patients: Particle Number and Dose for Lung Scintigraphy| Age | Newborn | 1 year | | 5 years | | 10 years | 15 years |
| Weight (kg) | 3.5 | | 12.1 | | 20.3 | | 33.5 | | 55 | |
| Maximal recommended dose | MBq | mCi | MBq | mCi | MBq | mCi | MBq | mCi | MBq | mCi |
| 18.5 | 0.5 | 22.2 | 0.6 | 37 | 1 | 62.9 | 1.7 | 103.6 | 2.8 |
| Range of particles | 10,000 to | 50,000 to | 200,000 to | 200,000 to | 200,000 to |
| administered | 50,000 | 150,000 | 300,000 | 300,000 | 700,000 |
Adults and Pediatric Patients
Visually inspect for particulate matter and discoloration prior to administration.
Measure the patient dose by a suitable radioactivity calibration system immediately prior to administration. Mix the contents of the vial by gentle inversion just prior to withdrawing a patient dose.
Mix the contents of the syringe just before injection. If blood is drawn into the syringe, any unnecessary delay prior to injection may lead to clot formation. For optimal results and because of rapid lung clearance of the radiopharmaceutical, position the patient under the imaging apparatus before administration. Slow injection is recommended. Lung imaging may begin immediately after intravenous injection of the radiopharmaceutical. Due to high kidney uptake, imaging later than one-half hour after administration will yield poor results.