A system and method for measurement of radioactivity concentration of a radiopharmaceutical are disclosed. The radiopharmaceutical may be a radioactive tracer solution including a tracer solution and a buffer solution. The system may include a vial that receives the tracer solution and the buffer solution; a scale; a radioactivity measuring device; and a controller that determines the radioactive concentration based on a measured radioactivity of the tracer solution and the buffer solution in the vial, and a weight of the tracer solution and the buffer solution in the vial. The method may include the steps of (1) transferring the tracer solution into a vial; (2) measuring a radioactivity of the tracer solution in the vial; (3) determining a weight necessary to achieve a desired radioactivity concentration; and (4) diluting the tracer solution in the vial to the determined weight with a buffer solution.