Quantitative bone scintigraphy in patients with prostatic carcinoma treated with LH-RH analogues

In 14 men with prostatic carcinoma, quantitative scintigraphy of the vertebrae from Th10 to L5 was performed before and 2 weeks and 2 and 6 months after start of treatment with luteinizing hormone-releasing hormone (LH-RH) analogues. Serum prostate-specific antigen (PSA) was also determined. The patients with normal bone scintigram showed no change in gamma camera count rate during the study, but fall in PSA values. The patients with abnormal bone scintigram responded to treatment with flare phenomenon, with increased count rate at 2 weeks, followed by fall to pretreatment level at 2 months. PSA showed decrease as early as 2 weeks after the start of treatment. Bone scintigraphy was found to be useful before therapy, especially in patients with elevated PSA levels, and after 2 months, when the flare phenomenon had subsided. Serial measurement of PSA provided a guide to disease activity.