Computerized bone scan. A potentially useful technique to measure response in prostatic carcinoma

Computerized bone scanning (CBS), a technique used to measure quantitative changes in bone scans, is described. Ten patients with histologically proven metastatic carcinoma of the prostate had sequential CBS performed. Good correlation was found between marked improvement in CBS (more than 50% average decrease in counts) and objective responses. Two patients had partial remission with more than 50% average decrease in uptake by prostatic cancer project criteria; both of them had good pain control. Three patients had worsening of their disease by CBS, which correlated with other parameters of disease progression (new lesions in bone survey, loss of weight and poor survival). In those patients with less than 50% average change the correlation is not so clear cut. An increase in percentage of uptake occurs in the first month after beginning of therapy, and no significant change is observed until 3 months. CBS is a technique that allows for objective measurement of quantitative changes in bone uptake, which is potentially useful for the evaluation of response to treatment in patients with metastatic bone disease from carcinoma of the prostate.