Androgen sensitivity of rat prostate carcinoma studied by 31P NMR spectroscopy, 1H MR imaging, and 23Na MR imaging.

31P NMR spectroscopy, 1H magnetic resonance (MR) imaging, and 23Na MR imaging were used to study the biochemical difference between nine hormone-sensitive and six hormone-resistant rat prostate cancers and to follow bioenergetic and morphologic changes subsequent to androgen deprivation in the hormone-sensitive model. Neither 1H nor 23Na MR image characteristics were useful in distinguishing androgen-sensitive from androgen-resistant prostate cancer nor in identifying androgen deprivation. 31P NMR spectroscopy did detect bioenergetic differences between the hormone-sensitive and hormone-resistant tumors. Baseline spectra showed a significantly higher PCr/ATP ratio (mean 0.86 +/- 0.09 SEM) for hormone-sensitive tumors than for hormone-resistant tumors (mean 0.26 +/- 0.07 SEM). By 3 days after androgen deprivation (orchiectomy (castration], PCr/ATP ratios had decreased noticeably; by 1 week, the decrease was statistically significant and remained so for the rest of the study (3 weeks). It appears that 31P NMR spectroscopy is useful in detecting androgen sensitivity of prostatic carcinoma.

The benefits of combining early radionuclide renal scintigraphy with routine bone scans in patients with prostate cancer.

Based upon the rapid early renal excretion of bone imaging radiopharmaceuticals, we performed a prospective study to determine the use of combining renal evaluation with routine bone scans in 79 consecutive patients with prostate cancer. The radionuclide renal scintigraphy consisted of a 1-minute sequence of 2.5-second frames with a bolus injection of 99mtechnetium-methylene diphosphonate followed by a series of 2-minute images for 24 minutes. Whole body bone scans were performed after a 3-hour delay. All patients had at least 1 confirmatory study with excretory urography (62), ultrasonography (49) or computerized tomography (30). Results were interpreted independently and compared. Ten studies were normal. Radionuclide renal scintigraphy was able to identify 45 of 49 cortical abnormalities (90 per cent) with a false positive rate of 4 per cent. Accuracy of renal cyst detection was only 47 per cent (15 of 32 cases). All acutely obstructed kidneys were identified correctly by radionuclide renal scintigraphy (5 of 5 cases). Of 12 chronically obstructed kidneys 8 (67 per cent) were identified correctly. The 4 missed kidneys were small and nonfunctioning, and they were diagnosed correctly as such but obstruction as the etiology of nonfunction was unidentifiable by radionuclide renal scintigraphy. The false positive rate of obstructive diagnosis by radionuclide renal scintigraphy was 24 per cent (4 of 17 cases). These findings demonstrate that renal evaluation combined with routine bone scanning is an effective screening procedure for renal complications of prostate cancer; no significant abnormalities were missed. The procedure is entirely free of morbidity and does not add to the radiation dose from the bone scan. Furthermore, it is cost-effective, since it avoids the routine need for 2 separate procedures at followup of patients with prostate cancer.