A correlative study ofin vivo andin vitro labeling index using bromodeoxyuridine in human brain tumors

The labeling index (LI) of 216 cases of human brain tumors was determined by the immunohistochemical technique with monoclonal antibody to bromodeoxyuridine (BrdU). The proliferative potential of 110 cases was estimated using the intra-operative intravenous infusion of BrdU at a dose of 200 mg/sq m. In another 106 cases, thein vitro technique of incubating freshly resected tumor tissue fragments with 100 M bromodeoxyuridine was used. The BrdU LI in these tumors was then correlated with the histological types and the data as determined by both thein vivo andin vitro BrdU incorporation were compared. The results indicate that althoughin vivo andin vitro techniques could possibly provide equivalent data in some histologic types, a clear statistically valid proof however is not apparent from this study.