Quantitative bone scintigraphy - A methodological evaluation in prostate cancer

Purpose: To evaluate a simple method for quantification of focal activity i n bone scintigraphy (BS). Material and Methods: The gamma camera was calibrated using a phantom. Quan titative bone scintigraphy (QBS) was performed on 11 men recently diagnosed with prostate cancer (PCa), for whom routine BS showed involvement of the skeleton. Following endocrine therapy for 4 to 8 months, a second QBS was p erformed. Changes in QBS values were then compared to changes in serum leve ls of prostate-specific antigen (PSA). Results: PSA response indicating regression of PCa was accompanied by a dec rease in the QBS value in 8 of the 11 patients. The overall mean error of t he QBS values was 15%. Conclusion: QBS according to this method is a relatively simple procedure t hat might contribute to objective evaluation of therapeutic effects in skel etal metastases, although its validity must be tested in a larger clinical material.