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Particle-size and radiochemical purity evaluations of filtered 99mTc-sulfur colloid prepared with different heating times.
J Nucl Med Technol. 2014 Dec; 42(4):283-8.JN

Abstract

Sentinel node lymphoscintigraphy using colloidal particles has become common practice at many institutions. The ideal particle size for colloids such as filtered (99m)Tc-sulfur colloid ((99m)Tc-FSC) in sentinel node studies is 15-100 nm. It is reported that the use of a reduced heating time during the reconstitution process results in an increased number of smaller particles (<30 nm). However, it is unclear whether these smaller particles (>15 nm) would be of benefit in sentinel node studies. This study sought to better define particle size by using electron microscopy, as well as to evaluate the radiochemical purity (RCP) of (99m)Tc-FSC at various time points after filtration.

METHODS

One group of (99m)Tc-sulfur colloid ((99m)Tc-SC) preparations was reconstituted using the standard heating time of 5 min, and another group was prepared using a reduced heating time of 3 min. The (99m)Tc-SC preparations were passed through a 0.2-μm filter, and retained filter activity was measured. RCP values were collected at 0, 1, 3, and 6 h after filtration, and the particle sizes were measured at 0 and 6 h after filtration.

RESULTS

Average RCP values (± SD) for (99m)Tc-FSC with 5-min heating were 98.4% ± 3.0% and 98.3% ± 1.8% for 0 h and 6 h, respectively (n = 6). Average RCP values for (99m)Tc-FSC with 3-min heating were 98.4% ± 4.1% and 96.9% ± 3.1% for 0 h and 6 h, respectively (n = 6). Electron microscopy data showed that median particle sizes for the 3-min heating at 0 and 6 h were 24 and 35 nm, respectively. Median particle sizes for the 5-min heating at 0 and 6 h were 29 and 27 nm, respectively. The proportion of particles within the ideal range for sentinel node lymphoscintigraphy was similar between the heating methods (91.1% for 3-min heating at 0 h and 88.8% for 5-min heating at 0 h, P = 0.1851).

CONCLUSION

Our results indicate that although there are slight significant differences in RCP value, particle size, and particle number for (99m)Tc-FSC prepared using either a standard or a reduced heating time, both methods produce particles within the optimum range for sentinel node studies.

Authors+Show Affiliations

Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, Minnesota; and.Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, Minnesota; and.Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, Minnesota; and.Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, Minnesota; and jhung@mayo.edu.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

25104817

Citation

Michenfelder, Maggie M., et al. "Particle-size and Radiochemical Purity Evaluations of Filtered 99mTc-sulfur Colloid Prepared With Different Heating Times." Journal of Nuclear Medicine Technology, vol. 42, no. 4, 2014, pp. 283-8.
Michenfelder MM, Bartlett LJ, Mahoney DW, et al. Particle-size and radiochemical purity evaluations of filtered 99mTc-sulfur colloid prepared with different heating times. J Nucl Med Technol. 2014;42(4):283-8.
Michenfelder, M. M., Bartlett, L. J., Mahoney, D. W., Herold, T. J., & Hung, J. C. (2014). Particle-size and radiochemical purity evaluations of filtered 99mTc-sulfur colloid prepared with different heating times. Journal of Nuclear Medicine Technology, 42(4), 283-8. https://doi.org/10.2967/jnmt.114.145391
Michenfelder MM, et al. Particle-size and Radiochemical Purity Evaluations of Filtered 99mTc-sulfur Colloid Prepared With Different Heating Times. J Nucl Med Technol. 2014;42(4):283-8. PubMed PMID: 25104817.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Particle-size and radiochemical purity evaluations of filtered 99mTc-sulfur colloid prepared with different heating times. AU - Michenfelder,Maggie M, AU - Bartlett,Lucas J, AU - Mahoney,Douglas W, AU - Herold,Thomas J, AU - Hung,Joseph C, Y1 - 2014/08/07/ PY - 2014/8/9/entrez PY - 2014/8/12/pubmed PY - 2016/1/5/medline KW - 99mTc-sulfur colloid KW - lymphoscintigraphy KW - preparation KW - radiopharmaceutical KW - radiopharmacy SP - 283 EP - 8 JF - Journal of nuclear medicine technology JO - J Nucl Med Technol VL - 42 IS - 4 N2 - UNLABELLED: Sentinel node lymphoscintigraphy using colloidal particles has become common practice at many institutions. The ideal particle size for colloids such as filtered (99m)Tc-sulfur colloid ((99m)Tc-FSC) in sentinel node studies is 15-100 nm. It is reported that the use of a reduced heating time during the reconstitution process results in an increased number of smaller particles (<30 nm). However, it is unclear whether these smaller particles (>15 nm) would be of benefit in sentinel node studies. This study sought to better define particle size by using electron microscopy, as well as to evaluate the radiochemical purity (RCP) of (99m)Tc-FSC at various time points after filtration. METHODS: One group of (99m)Tc-sulfur colloid ((99m)Tc-SC) preparations was reconstituted using the standard heating time of 5 min, and another group was prepared using a reduced heating time of 3 min. The (99m)Tc-SC preparations were passed through a 0.2-μm filter, and retained filter activity was measured. RCP values were collected at 0, 1, 3, and 6 h after filtration, and the particle sizes were measured at 0 and 6 h after filtration. RESULTS: Average RCP values (± SD) for (99m)Tc-FSC with 5-min heating were 98.4% ± 3.0% and 98.3% ± 1.8% for 0 h and 6 h, respectively (n = 6). Average RCP values for (99m)Tc-FSC with 3-min heating were 98.4% ± 4.1% and 96.9% ± 3.1% for 0 h and 6 h, respectively (n = 6). Electron microscopy data showed that median particle sizes for the 3-min heating at 0 and 6 h were 24 and 35 nm, respectively. Median particle sizes for the 5-min heating at 0 and 6 h were 29 and 27 nm, respectively. The proportion of particles within the ideal range for sentinel node lymphoscintigraphy was similar between the heating methods (91.1% for 3-min heating at 0 h and 88.8% for 5-min heating at 0 h, P = 0.1851). CONCLUSION: Our results indicate that although there are slight significant differences in RCP value, particle size, and particle number for (99m)Tc-FSC prepared using either a standard or a reduced heating time, both methods produce particles within the optimum range for sentinel node studies. SN - 1535-5675 UR - https://www.unboundmedicine.com/medline/citation/25104817/Particle_size_and_radiochemical_purity_evaluations_of_filtered_99mTc_sulfur_colloid_prepared_with_different_heating_times_ DB - PRIME DP - Unbound Medicine ER -