Medical Radiology and Radiation Safety. 2015. Vol. 60. No. 6. P. 42-47

NUCLEAR MEDICINE

Mathematical Simulation of Transport Kinetics of Radiopharmaceutical ⁶⁸Ga-Citrate for PET Imaging of Inflammation

1. A.I. Burnasyan Federal Medical Biophysical Center of FMBA, Moscow, Russia, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. ; 2. Moscow State Academy of Veterinary Medicine and Biotechnology, Moscow, Russia

ABSTRACT

Purpose: ⁶⁸Ga-citrate is ⁶⁷Ga-citrate analogue and prospective radiopharmaceutical for PET imaging of inflammation and infection. However, some pharmacokinetic hardships such as low blood clearance and long accumulation time in foci (24-72 h) except application possibility of the short-lived gallium-68 (T_1/2 = 68 min). Proposed solution of this problem (extra injection of competitive chemical agent; here: Fe-citrate) should be proved quantitatively. Therefore the aim of this study is the creation of a mathematical (compartment) model for the transport kinetics of radiopharmaceutical Ga-citrate with extra injection of stable Fe-citrate.

Material and methods: Ga-citrate and stable Fe-citrate for i. v. injection are the objects of our study. Nonlinear rats’ females (two groups: with/without extra injection of Fe-citrate) with soft tissue inflammation were used. Mathematical simulation of transport kinetics for calculation of pharmacokinetic parameters was created according to the rats’ biodistribution of Ga-citrate.

Results: Extra i. v. injection of Fe-citrate allowed accelerating blood clearance from Ga-citrate, significantly decelerated its liver accumulation and excretion through intestine. Moreover, extra injection of Fe-citrate allowed for the increase of Ga-citrate accumulation and retention in inflammation site.

Conclusion: Mathematical calculations quantitatively confirmed that extra injection of Fe-citrate had a positive impacted on PET imaging of inflammation.

Key words: Ga-citrate, radiopharmaceutical, mathematical simulation, compartment model

REFERENCES

1. Stabin M.G., Siegel J.A. Physical models and dose factors for use in internal dose assessment. Health Phys. 2003. Vol. 85. No. 3. P. 294-302.
2. Klepov A.N., Kurachenko Yu.A., Levchenko V.A., Matusevich E.S. Primenenie metodov matematicheskogo modelirovaniya v yadernoi meditsine. In E.S. Matusevicha (ed.). Obninsk. 2006. 204 p. (In Russ.).
3. Dolya O.P. (Aleksandrova O.P.), Matusevich E.S., Klepov A.N. Matematicheskoe modelirovanie kinetiki transporta osteotropnogo radiofarmpreparata v organizme patsientov s metastazami v kosti. Med. fizika. 2007. No. 2. P. 40-50. (In Russ.).
4. Lavender J.P., Lowe J., Barker J. Gallium 67 citrate scanning in neoplastic and inflammatory lesions. Brit. J. Radiol. 1971. Vol. 44. P. 361-366.
5. Hoffer R. Gallium: mechanisms. J. Nucl. Med. 1980. Vol. 21. No. 3. P. 282-285.
6. Harris W.R., Pecoraro V.L. Thermodynamic binding constants for gallium transferrin. Biochem. 1983. Vol. 22. P. 292-299.
7. Denisov A.M. Vvedenie v teoriyu obratnykh zadach. Moscow: MGU. 1994. 208 p. (In Russ.).

For citation: Lunev AS. Mathematical Simulation of Transport Kinetics of Radiopharmaceutical ⁶⁸Ga-Citrate for PET Imaging of Inflammation. Medical Radiology and Radiation Safety. 2015;60(6):42-7. Russian.

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