Changes in 87mSr concentractions in skeletal metastases in patients responding to cyclical combination chemotherapy for advanced breast cancer.

Serial 87mSr bone scintigrams were performed on a series of patients being treated by cyclical combination chemotherapy for metastatic breast cancer. All the patients investigated responeded to the chemotherapy, but initially the scintigrams showed an apparent deterioration, in that the tumor-to-normal isotope uptake ratios increased. Following this initial "flare" the scintigram appearance improved with a decrease in the tumor-to-normal uptake ratio. It is suggested that deterioration in the scintigram in the early stages of treatment should not be regarded as an indication that the patient is failing to respond.