Total bone uptake in management of metastatic carcinoma of the prostate

The status of patients with skeletal metastases from prostatic carcinoma was determined from a quantitative uptake and retention measurement of the bone scanning radiopharmaceutical 99mtechnetium-methylene diphosphonate. Whole body counts were performed 5 minutes and 24 hours after intravenous administration of 99mtechnetium-methylene diphosphonate, and were expressed as the percentage uptake by the skeleton at 24 hours. Skeletal uptake determinations were done in 29 patients with prostatic cancer (17 with osseous metastases) who were evaluated at 3 to 6-month intervals. Group 1 consisted of patients who responded to therapy and achieved remission, group 2 included patients with relapse or progressive disease, group 3 consisted of those with metastases who were in remission for longer than 6 months and group 4 included those without evidence of any bony metastases. The baseline mean +/- standard deviation 24-hour skeletal uptake values were 46.1 +/- 12.0 per cent in group 1, 34.3 +/- 13.9 per cent in group 2, 27.0 +/- 5.9 per cent in group 3 and 28.9 +/- 5.5 per cent in group 4. At 3 to 6 months the values in group 1 (responders) decreased by 18 per cent, while those in group 2 (relapse or progression) increased by 19 per cent and those in group 3 (remission) increased by 1.5 per cent. The quantitative 24-hour skeletal uptake test was performed easily, reproducible and at least as useful as concurrent chemical blood tests and subjective bone scan interpretations.