Radioisotopic bone scintigraphy with the gamma camera in the investigation of prostatic cancer

Experience with x-rays, strontium-87m scintigraphy, and technetium-99m polyphosphate scintigraphy in the identification of bone metastases in 201 patients with prostatic cancer is reviewed. About 40% of the patients had demonstrable metastases in bone at the time of first presentation.Comparative studies of 247 x-ray and (87m)Sr surveys indicated that x-rays failed to detect metastases in 10% of cases where they were identified by (87m)Sr but that the isotopic survey similarly failed to detect radiologically evident deposits in 7% of cases.Similar studies comparing (99m)Tc polyphosphate surveys with x-ray scans showed that x-rays missed isotopically detected metastases in 12% of cases, but in only one survey out of 67 did the isotope miss radiologically evident deposits. In a series of 32 patients investigated by both isotopic techniques (99m)Tc polyphosphate did not fail to detect any metastases and identified deposits in one patient in whom they were missed by (87m)Sr scintigraphy. About 15% of both x-ray and (87m)Sr surveys gave equivocal results, but only 3% (2 out of 67) of (99m)Tc polyphosphate surveys were equivocal.We concluded that (99m)Tc polyphosphate bone scintigraphy with the gamma camera was the most reliable of the techniques used for the identification of bone metastases in patients with carcinoma of the prostate. The results of scintigraphy with (87m)Sr suggested that serial surveys may provide early evidence of hormone resistance in prostatic cancer.