Purpose: To determine whether it is possible to select patients in whom and for what reason bone scintigraphy should be performed or not, a retrospective study was performed of 161 consecutive patients with newly diagnosed prostate cancer.
Materials and methods: Follow-up varied from 1 to 88 months during which 67 patients died. Bone scans were classified from 0 (= normal) to 3 (typical pattern of metastases) and were correlated with age, alkaline phosphatase (AP), prostate specific antigen (PSA), tumor grade, TNM-stage and survival. For survival, 68 patients who were not referred for bone scintigraphy were also evaluated.
Results: All parameters demonstrated a correlation with the incidence of a positive bone scan, but PSA was the best overall predictor in this (p < 0.0001). None of the patients with PSA < or = 20 ng/ml (n = 64) showed metastases, whereas 8 of 9 patients with PSA > 1000 ng/ml and patients with PSA values between 20 and 1000 ng/ml in combination with AP > 90 U/L (n = 24) had bone metastases. Furthermore, a class 3 bone scan was found to be the most important parameter in assessing prognosis and survival (p < 0.0001), whereas no differences were found in patients with a class 0, 1 and 2 scintigram.
Conclusions: For staging and prognostic stratification purposes, bone scintigraphy and additional roentgenograms are of value in a selected group of patients. In contrast with a typical pattern of metastases on bone scintigraphy, an abnormal scan (class 1 and 2) at the time of diagnosis is not a poor prognostic parameter of the risk of death. Bone scintigraphy can be omitted in patients with PSA values < 20 ng/ml. In patients with PSA levels > 1000 ng/ml or less increased levels combined with alkaline phosphatase levels > 90 U/L, bone scintigraphy seems to be of no value in staging disease.