Gastric uptake during Re-186 HEDP bone scintigraphy.

In bone scintigraphy extraosseous uptake of the radiopharmaceutical (TcO4-, pertechnetate) is a common finding when the stomach is abnormally observed; this may be due to the instability of the radiopharmaceutical leading to free pertechnetate within this organ. The same explanation might be inculpate rhenium 186-HEDP, due to its similarity to Tc-99m MDP's sphysicochemical properties and behavior, as both radioisotopes are Group VII metals /1/ and are labelling the same ligand (a diphosphonate moiety). We report on 186Re-HEDP uptake in the stomach in two patients with osseous metastases because of prostate and breast cancer respectively out of a series of 52 cancer affected individuals, treated with 186Re-HEDP. The thorough clinical and laboratory investigation of both patients assessed that this extraosseous radio-rhenium accumulation was multifactorial with the main cause being a disturbance of body fluid acid-balance, favoring calcium and phosphate ion precipitation and leading to 186Re-HEDP extraosseous uptake.