Technical notes
184
Acknowledgement-This project was partially supported by the Michael Reese Research Institute. LELIO G. COLOMBETTI STEPHEN MoERLIEN STEVEN PINSKY
Pharmacology Department Loyola University Stritch School of Medicine and Michael Reese Hospital and Medical Center 29th Street and Ellis Avenue Chicago, Illinois 60616, U.S.A. References 1. BENACERRAF B., Bmzzi G., HALPERN B. and STIFFEL C. Res. Bull. 2, 19 (1956). 2. TAPLIN G. D., DoRE E. K., joHNSON D. E. and KAPLAN H. lOth Annual Meeting of the Nuclear Medicine Society, Montreal, Canada, (1963). 3. BIOZZI G., BENACERRAF B., HALPERN B., STIFFEL C. and HILLEMAND B. J. Lab. clin. Med. 51, 230 (1958). 4. McAFFEE J. G., STERN H. S., FUEGER G. F., BAGGISH M.S., HoLZMAN G. B. and ZoLLE I. J. nucl. Med. 5, 936 (1964). 5. GwYTHER M. M. and FIELD E. 0. Int. J. appl. Radiat. Isotopes, 17, 485 (1966). 6. DEUTSCH M. E. and REDMOND M. L. J. nucl. Med. 13, 426 (1972). 7. HoNDA T., KAZEM I., CROLL M. N. and BRADY L. W. J. nucl. Med. 11, 580 (1970). 8. TAPLIN G. V., GRISWOLD L. M., HuRWIT ]., and jOHNSON D. E. J. nucl. Med. 8, 303 (1967). 9. SuBRAMANIAN G., ARNOLD L. W., THoMAs F. D., and McAFFEE J. G. J. nucl. Med. 13, 790 ( 1972). 10. RoBINS P. ]., FoRTMAN D. L., and LEWIS J. T. J. nucl. Med. 13, 463 (1972). 11. CoLOMBETTI L. G., GooDWIN D. A. and HINKLEY R. L. J. nucl. Med. 10, 633 (1969). 12. CoLOMBETTIL. G.,GooDwiND.A.and ToGAMIE. J. nucl. Med. 11, 704 (1970). 13. CoLOMBETTI L. G., LoPEZ-MAJANO V. and KAPLAN E. Proc. Int. Symp. Nucl. Med., in press, Karlovy-Vary, 1973. a. CoLoMBETTIL. G.,LoPEz-MAJANo v.,KAPLANE. and FELLO M. Rev. Iner. de Radial. 8 (1973). 15. CoLOMBETTI L. G., PINSKY S. and MoERLIEN S. Radiochem. Radioanalyt. Lett., 20, 77 (1974). 16. WoLF P. L. Methods and Techniques in Clinical Chemistry, p. 353. Wiley-Interscience, New York ( 1972). 17. TAPLIN G. V., and MAcDoNALD N. S. Seminars in nucl. Med. 1, 132 (1971).
International Journal of Nuclear Medicine and Biology, 1975, Vol. 2 pp. 184-185. Pergamon Press. Printed in Northern Ireland
An Alternate Approach to the Preparation of 99mTc-Sulfur Colloid (Received 17 February 1975) Introduction 99mTc-suLFUR
colloid has gained wide acceptance as the choice radiopharmaceutical for scanning the reticuloendothelial system. The labelled colloid particulate matter is accumulated preferentially by the Kupffer cells of the RE system by phagocytosis. There are a number of procedures for the preparation of this radiopharmaceutical. The earlier methods employed the use of hydrogen sulfide gas 11 •2 > or sodium thiosulfate with or without the presence of sodium perrrhenate as carrier.W Gelatin,(l) dextran, polyvinyl pyrrolidone,< 6 > mannitol< 7 > and citric acid have been used as stabilizers of the colloid in these preparations, although the stabilizing function of mannitol for hydrophobic colloids has been questioned. Phosphate has generally been used as the buffering medium to maintain the pH conditions but sometimes citrate< 8 >has also been used. BoYD(lO) and CIFKA< 11 >have made a detailed study of the various parameters influencing the preparation of 99mTc-sulfur colloid. BRuuNI12 > has commented on the particle size generally encountered in the labelled colloidal material and its instability and hence its possible propensity to retain in the lungs. This study presents the use of minimal yet effective quantities of sodium thiosulfate in the preparation of the colloid, which is stabilized with the polyhydric alcohol mannitol and buffered with sodium citrate. The entire preparation is completed in the shortest possible time. The content of sulfur in the total preparation is less than 0·2 mg/ml. This method has been routinely followed at our Centre for the preparation of 99mTc-sulfur colloid radiopharmaceutical for use in humans for the purpose of scanning the RE system.
Materials and Methods Sodium pertechnetate (99 mTc0 4-) was obtained by the organic solvent (methyl ethyl ketone) extraction process from sodium molybdate (99 Mo) and purified. t13l All reagents were prepared in large quantities using water for i~ection for both dissolution and dilution, and sterilized by passing through a 0·22 micron Millipore membrane filter and distributed in single-dose vials ( 10 ml capacity) and subsequently
185
Technical notes autoclaved at 120°C ( 15 psi). The final volumes were taken in sterile, disposable, graduated syringes. The following reagents were used in the preparation of 99 mTc-sulfur colloid. (a) Reaction solution: a mixture of 2 ml of 5% mannitol solution together with 0·3 ml of l% sodium thiosulfate solution (1·4 mg of S). (b) Acid: 0·5 ml of l N Hydrochloric acid; (c) Buffer: 1 ml of l M sodium citrate solution. Preparation of the colloid. A sterile solution of 99 mTc0 - (l-5 ml) in normal saline was added to the 4 reaction solution and then 0·5 ml of acid was asceptically transferred into it, followed by heating the vial in a boiling water bath for 5 min. It was then cooled in air for a minute and under running tap water for 2 min and finally the buffer was asceptically added to it, and the contents were well mixed. The final pH was 6·2-6·5; and the product was ready for use in humans. This radiopharmaceutical has been used clinically within 6 hr after the preparation.
Results Biological criteria. Since the commonly employed procedures in paper chromatography using 85: 15 methanol-water solvent do not serve as a good index for critical evaluation of the radiopharmaceutical, biological distribution in mice (Swiss-strain) was adopted for purposes of quality control. Invariably the percentage uptake of the injected dose in the liver at the time of sacrifice (15 min) was 90 ± 3·0, and in the spleen 2·5 ± 0·5. Very little activity was retained in the lungs, thyroid, stomach-intestines and the kidneys. The blood background was negligible, thus showing the abscence of any unlabelled free 99 mTc04and the efficiency of the labelling process. Effect of autoclaving. Tissue distribution studies in mice have indicated that even if the slightly opalescent 99 mTc sulfur colloid was autoclaved at l20°C at 15 psi TABLE l. Organ distribution of 99 mTc-sulfur colloid in mice % Administered dose 99 mTc-S colloid colloid (Autoclaved) product) (Normal 99 "'Tc-S
Liver Spleen Lungs Stomach)
inte~ines Kidneys Blood
90·0 ± 3·0 2·6 ± 0·5 0·4 ± 0·2
85 ± 5·0 2·3 ± 0·3 0·4 ± 0·2
0·4 ± 0·1
1·5 ± 0·3
0·1 ± 0·1 0·25 ± 0·15
0·2 ± 0·1 0-4 ± 0·1
Numberofanimals: 20. Timeofsacrifice: 15 min.
for 20 min, when it turned into a clear solution, the concentration in the liver and spleen were not markedly changed as shown in Table I. Little activity was seen in the stomach and intestines. The pH value and the paper chromatographic patterns (R1 = 0) were not altered. 0. P. D. NoRONHA Radiation Medicine Centre Bhabha Atomic Research Centre A. B. SEWATKAR R. D. GANATRA Tata Memorial Hospital H. J. GLENN* Parel, Bombay-400 012 India
References 1. HARPER P. V., LATHROP K. A. and RICHARDS P. J. nucl. Med. 5, 382 (1964). 2. HARPER P. v., LATHROP K. A., JIMINEZ F., FINK R. and GoTTSCHALK A. Radiology 85, 10 l (1965). 3. PATTON D. D., GARciA E. N. and WEBER M. M. Am. J. Roentgenol. Radiat. ther. nucl. Med. 91, 880 ( 1966). 4. STERN H. S., McAFEE J. G. and SuBRAMANIAN G. J. nucl. Med. 7, 665 (1966). 5. LARSON S. M. and NELP W. B. J. nucl. Med. 7, 817 (1966). 6. SzYMENDERA J., ZoLTOWSKI T., RADWAN M. and KAMINSKAj. J. nucl. Med.12,212 (1971). 7. HuNTERjR. W. W. J. nucl. Med. 10,607 (1969). 8. STAUM M. M. J. nucl. Med. 13, 386 (1972). 9. HALL J. N., O'MARA R. E. and TYSON I. J. nucl. Med. 13, 868 (1972). 10. BoYD R. E. Radiopharmaceuticals from Generator Produced Radionuclides-Panel Proceeding Series p. 56. IAEA, Vienna (1971). 11. CIFKA J. and V ESE LEY P. Radiopharmaceuticals and Labelled Compounds-Proceedings of a Symposium, Vol. 1, p. 53. IAEA, Vienna (1973). 12. BRUUN P. J. nucl. Med. 15, 726 (1974). 13. SEwATKAR A. B., NoRONHA 0. P. D., GANATRA R. D. and GLENN H. J. Nuclear-Medi;:,in 14, 46 (1975). International Journal of Nuclear Medicine and Biology, 1975, Vol. 2, pp. 185-188. Pergamon Press, Printed in Northern Ireland
Estitnation of Thyroid Weight by Scintigraphy
(Received 13 June 1974; in revisedform 23 December 1974) The majority of authors agree that thyroid weight must be taken into account when estimating the * W.H.O. visiting scientist.
184
Acknowledgement-This project was partially supported by the Michael Reese Research Institute. LELIO G. COLOMBETTI STEPHEN MoERLIEN STEVEN PINSKY
Pharmacology Department Loyola University Stritch School of Medicine and Michael Reese Hospital and Medical Center 29th Street and Ellis Avenue Chicago, Illinois 60616, U.S.A. References 1. BENACERRAF B., Bmzzi G., HALPERN B. and STIFFEL C. Res. Bull. 2, 19 (1956). 2. TAPLIN G. D., DoRE E. K., joHNSON D. E. and KAPLAN H. lOth Annual Meeting of the Nuclear Medicine Society, Montreal, Canada, (1963). 3. BIOZZI G., BENACERRAF B., HALPERN B., STIFFEL C. and HILLEMAND B. J. Lab. clin. Med. 51, 230 (1958). 4. McAFFEE J. G., STERN H. S., FUEGER G. F., BAGGISH M.S., HoLZMAN G. B. and ZoLLE I. J. nucl. Med. 5, 936 (1964). 5. GwYTHER M. M. and FIELD E. 0. Int. J. appl. Radiat. Isotopes, 17, 485 (1966). 6. DEUTSCH M. E. and REDMOND M. L. J. nucl. Med. 13, 426 (1972). 7. HoNDA T., KAZEM I., CROLL M. N. and BRADY L. W. J. nucl. Med. 11, 580 (1970). 8. TAPLIN G. V., GRISWOLD L. M., HuRWIT ]., and jOHNSON D. E. J. nucl. Med. 8, 303 (1967). 9. SuBRAMANIAN G., ARNOLD L. W., THoMAs F. D., and McAFFEE J. G. J. nucl. Med. 13, 790 ( 1972). 10. RoBINS P. ]., FoRTMAN D. L., and LEWIS J. T. J. nucl. Med. 13, 463 (1972). 11. CoLOMBETTI L. G., GooDWIN D. A. and HINKLEY R. L. J. nucl. Med. 10, 633 (1969). 12. CoLOMBETTIL. G.,GooDwiND.A.and ToGAMIE. J. nucl. Med. 11, 704 (1970). 13. CoLOMBETTI L. G., LoPEZ-MAJANO V. and KAPLAN E. Proc. Int. Symp. Nucl. Med., in press, Karlovy-Vary, 1973. a. CoLoMBETTIL. G.,LoPEz-MAJANo v.,KAPLANE. and FELLO M. Rev. Iner. de Radial. 8 (1973). 15. CoLOMBETTI L. G., PINSKY S. and MoERLIEN S. Radiochem. Radioanalyt. Lett., 20, 77 (1974). 16. WoLF P. L. Methods and Techniques in Clinical Chemistry, p. 353. Wiley-Interscience, New York ( 1972). 17. TAPLIN G. V., and MAcDoNALD N. S. Seminars in nucl. Med. 1, 132 (1971).
International Journal of Nuclear Medicine and Biology, 1975, Vol. 2 pp. 184-185. Pergamon Press. Printed in Northern Ireland
An Alternate Approach to the Preparation of 99mTc-Sulfur Colloid (Received 17 February 1975) Introduction 99mTc-suLFUR
colloid has gained wide acceptance as the choice radiopharmaceutical for scanning the reticuloendothelial system. The labelled colloid particulate matter is accumulated preferentially by the Kupffer cells of the RE system by phagocytosis. There are a number of procedures for the preparation of this radiopharmaceutical. The earlier methods employed the use of hydrogen sulfide gas 11 •2 > or sodium thiosulfate with or without the presence of sodium perrrhenate as carrier.W Gelatin,(l) dextran, polyvinyl pyrrolidone,< 6 > mannitol< 7 > and citric acid have been used as stabilizers of the colloid in these preparations, although the stabilizing function of mannitol for hydrophobic colloids has been questioned. Phosphate has generally been used as the buffering medium to maintain the pH conditions but sometimes citrate< 8 >has also been used. BoYD(lO) and CIFKA< 11 >have made a detailed study of the various parameters influencing the preparation of 99mTc-sulfur colloid. BRuuNI12 > has commented on the particle size generally encountered in the labelled colloidal material and its instability and hence its possible propensity to retain in the lungs. This study presents the use of minimal yet effective quantities of sodium thiosulfate in the preparation of the colloid, which is stabilized with the polyhydric alcohol mannitol and buffered with sodium citrate. The entire preparation is completed in the shortest possible time. The content of sulfur in the total preparation is less than 0·2 mg/ml. This method has been routinely followed at our Centre for the preparation of 99mTc-sulfur colloid radiopharmaceutical for use in humans for the purpose of scanning the RE system.
Materials and Methods Sodium pertechnetate (99 mTc0 4-) was obtained by the organic solvent (methyl ethyl ketone) extraction process from sodium molybdate (99 Mo) and purified. t13l All reagents were prepared in large quantities using water for i~ection for both dissolution and dilution, and sterilized by passing through a 0·22 micron Millipore membrane filter and distributed in single-dose vials ( 10 ml capacity) and subsequently
185
Technical notes autoclaved at 120°C ( 15 psi). The final volumes were taken in sterile, disposable, graduated syringes. The following reagents were used in the preparation of 99 mTc-sulfur colloid. (a) Reaction solution: a mixture of 2 ml of 5% mannitol solution together with 0·3 ml of l% sodium thiosulfate solution (1·4 mg of S). (b) Acid: 0·5 ml of l N Hydrochloric acid; (c) Buffer: 1 ml of l M sodium citrate solution. Preparation of the colloid. A sterile solution of 99 mTc0 - (l-5 ml) in normal saline was added to the 4 reaction solution and then 0·5 ml of acid was asceptically transferred into it, followed by heating the vial in a boiling water bath for 5 min. It was then cooled in air for a minute and under running tap water for 2 min and finally the buffer was asceptically added to it, and the contents were well mixed. The final pH was 6·2-6·5; and the product was ready for use in humans. This radiopharmaceutical has been used clinically within 6 hr after the preparation.
Results Biological criteria. Since the commonly employed procedures in paper chromatography using 85: 15 methanol-water solvent do not serve as a good index for critical evaluation of the radiopharmaceutical, biological distribution in mice (Swiss-strain) was adopted for purposes of quality control. Invariably the percentage uptake of the injected dose in the liver at the time of sacrifice (15 min) was 90 ± 3·0, and in the spleen 2·5 ± 0·5. Very little activity was retained in the lungs, thyroid, stomach-intestines and the kidneys. The blood background was negligible, thus showing the abscence of any unlabelled free 99 mTc04and the efficiency of the labelling process. Effect of autoclaving. Tissue distribution studies in mice have indicated that even if the slightly opalescent 99 mTc sulfur colloid was autoclaved at l20°C at 15 psi TABLE l. Organ distribution of 99 mTc-sulfur colloid in mice % Administered dose 99 mTc-S colloid colloid (Autoclaved) product) (Normal 99 "'Tc-S
Liver Spleen Lungs Stomach)
inte~ines Kidneys Blood
90·0 ± 3·0 2·6 ± 0·5 0·4 ± 0·2
85 ± 5·0 2·3 ± 0·3 0·4 ± 0·2
0·4 ± 0·1
1·5 ± 0·3
0·1 ± 0·1 0·25 ± 0·15
0·2 ± 0·1 0-4 ± 0·1
Numberofanimals: 20. Timeofsacrifice: 15 min.
for 20 min, when it turned into a clear solution, the concentration in the liver and spleen were not markedly changed as shown in Table I. Little activity was seen in the stomach and intestines. The pH value and the paper chromatographic patterns (R1 = 0) were not altered. 0. P. D. NoRONHA Radiation Medicine Centre Bhabha Atomic Research Centre A. B. SEWATKAR R. D. GANATRA Tata Memorial Hospital H. J. GLENN* Parel, Bombay-400 012 India
References 1. HARPER P. V., LATHROP K. A. and RICHARDS P. J. nucl. Med. 5, 382 (1964). 2. HARPER P. v., LATHROP K. A., JIMINEZ F., FINK R. and GoTTSCHALK A. Radiology 85, 10 l (1965). 3. PATTON D. D., GARciA E. N. and WEBER M. M. Am. J. Roentgenol. Radiat. ther. nucl. Med. 91, 880 ( 1966). 4. STERN H. S., McAFEE J. G. and SuBRAMANIAN G. J. nucl. Med. 7, 665 (1966). 5. LARSON S. M. and NELP W. B. J. nucl. Med. 7, 817 (1966). 6. SzYMENDERA J., ZoLTOWSKI T., RADWAN M. and KAMINSKAj. J. nucl. Med.12,212 (1971). 7. HuNTERjR. W. W. J. nucl. Med. 10,607 (1969). 8. STAUM M. M. J. nucl. Med. 13, 386 (1972). 9. HALL J. N., O'MARA R. E. and TYSON I. J. nucl. Med. 13, 868 (1972). 10. BoYD R. E. Radiopharmaceuticals from Generator Produced Radionuclides-Panel Proceeding Series p. 56. IAEA, Vienna (1971). 11. CIFKA J. and V ESE LEY P. Radiopharmaceuticals and Labelled Compounds-Proceedings of a Symposium, Vol. 1, p. 53. IAEA, Vienna (1973). 12. BRUUN P. J. nucl. Med. 15, 726 (1974). 13. SEwATKAR A. B., NoRONHA 0. P. D., GANATRA R. D. and GLENN H. J. Nuclear-Medi;:,in 14, 46 (1975). International Journal of Nuclear Medicine and Biology, 1975, Vol. 2, pp. 185-188. Pergamon Press, Printed in Northern Ireland
Estitnation of Thyroid Weight by Scintigraphy
(Received 13 June 1974; in revisedform 23 December 1974) The majority of authors agree that thyroid weight must be taken into account when estimating the * W.H.O. visiting scientist.
