Experience with 7,604 bone scintigraphies at time of operation for breast cancer 1977-1987.

From 1977 to 1987, 7,604 out of a total of 20,483 Danish breast cancer patients had a bone scintigraphy in order to exclude or localise osseous metastases. The scintigrams were performed and interpreted at 14 local hospitals. In 1979, standardised guidelines for interpretation were agreed upon. Until 1983, the scintigrams were described centrally, based on the local reports. From 1979, the frequency of positive bone scintigrams suggesting bone metastases stabilised at about 5% of the patients compared with 12 and 20% in 1977-78. The local take-over of description did not change the frequency. The frequency was also stable from 1979 when evaluated in age groups. With increasing age the frequency of positive scintigrams increased. The frequency of positive scintigrams was significantly lower in patients entering a protocol than in those not entering a protocol. The conclusion is that on a nation-wide basis it is possible to establish a stable, uniform interpretation of bone scintigrams after a two-year introduction period.