[Production of 99mTc-Antimony Sulfide Colloid for lymphoscintigraphy]

The lymphatic system provides one of the main paths for the spread (Metastasis) of cancer from one part of body to another. Hodgkin’s diseases, lymphocytic leukemia, various metastatic disease and many lymph node disorders can be assessed by lymphoscintigraphy. Radionuclide lymphoscintigraphy has been used for many years to define lymphatic drainage of melanoma. The most common radiopharmaceuticals used for lymphoscintigraphy are 99mTc-SC, 99mTc-antimony sulfide colloid and 99mTc-HSA-nanocolloid. Preparation of 99mTc-antimony sulfide colloid has been chosen among other colloids. For antimony colloid preparation, hydrogen sulfide gas was passed through D.W. until saturation. Antimony potassium tartrate is then added to the solution to form Sb2S3 colloid. The colloid was stabilized with P.V.P. Excess H2S was removed by bubbling with nitrogen. The preparation was then filtered through a 0.22μm membrane filter and aliquots containing 1.017mg Sb2S3 were dispensed into kit vials. Labeling was accomplished by adding 99mTcO-4 and HCl to the vial then heating it at 100°C in boiling water bath for 10 min. The pH was adjusted by adding a phosphate buffer. The radiochemical purity of 99mTc-antimony trisulfide colloid by ITLC-SG/normal saline was more than 95 percent. The amount of Sb in reaction vial was 0.729mg. The study demonstrated that our formulation of antimony sulfide, which has 0.0486mg (Sb) in 0.2ml for injection per patient (Total volume after labeling with 99mTc is 3ml).