CLINICAL-SIGNIFICANCE OF TC-99M METHYLENE DIPHOSPHONATE MYOCARDIAL UPTAKE - ASSOCIATION WITH CARCINOMA OF THE PROSTATE

Benign myocardial uptake of technetium-99m labelled phosphates, not re lated to cardiac or metabolic disorders, has been documented except in the case of Tc-99m-methylene diphosphonate (MDP). The aim of this stu dy was to assess the frequency of myocardial uptake and its possible a ssociation with malignant tumours in general and prostatic carcinoma i n particular. We reviewed bone scintigrams performed with either Tc-99 m-hydroxydiphosphonate (HDP) or Tc-99m-MDP over a period of more than 2 years for all patients with prostatic carcinoma and a matching group of patients suffering from other malignant and non-malignant disorder s. A total of 965 scintigrams of 812 patients (males=559, females=253; age range 50-91 years, average age 69.2 years) were reviewed. Increas ed myocardial uptake was detected in 19 scintigrams (MDP=13, HDP=B) of 18 patients (17 males, one female). Most of the male patients with in creased myocardial uptake had prostatic carcinoma (13/17) and were ove r 80 years of age (12/17), All patients were free of any cardiac or no ncardiac disorder that might account for such uptake. When scintigraph y was repeated in the same patient, the uptake of Tc-99m-HDP was more diffuse and of higher grade than that of Tc-99m-MDP. ''Benign'' myocar dial uptake of Tc-99m-MDP is more common than previously thought. Alth ough uptake of radiophosphates is attributed to asymptomatic atheroscl erotic changes associated with old age, a strong association with pros tatic carcinoma exists which may indicate variations in the bone: soft tissue affinity of different MDP complexes.