[Studies on surgical preparations for the concentration of radionuclides in brain tumors]

A total of 69 surgical preparations were used to determine the tumor-brain quotients of a number of radiopharmaceuticals and compare them with data reported in the literature of which the majority were externally measured values. The increases in activity of the tumor were on average, 2.5 times (131-J-HSA), 2.9 times (99m-Tc-pertechnate), and 3-5 times (197-Hg-Neohydrin) higher than those of the brain tissue. The lowest tumor-brain quotients were obtained for astrocytomas regardless of the radiopharmaceutical used, while high values were found for meningiomas, glioblastomas, and some of the spongioblastomas. In 44 cases tumor-brain quotients could be compared with scintigraphic results of which 36 were positive. Tumors having values less than 1-5 could not be scintigraphed. In the case of a negative scintigram of the brain the size and location relative to the base of the skull played a significant role although the tumor-brain quotient was high.