Abstract: Objective To explore and analyze imaging by bremsstrahlung phenomenon after ⁸⁹Sr administration in patients with bone metastases.And then monitoring distribution of the bone-seeking radiopharmaceutical ⁸⁹Sr in body and evaluating the feasibility of the method.Methods Bremsstrahlung imaging was performed in 15 patients in the 7th day after ⁸⁹Sr administration and there was comparision between it and ^99mTc-methylene bisphosphonate(MDP)bone scans.The region of interest(ROI)was outlined and then target/non-target ratio(T/NT ratio)was calculated.And a follow-up was made to observe thesis ache alleviation degree.Results Images gotten by ⁸⁹Sr bremsstrahlung imaging are similar to those by ^99mTc-MDP bone imaging,but the image reslution is less than the latter.T/NT ratio was about 3.13±1.03(1.24-5.81).Conclusion With skeletal metastases through calculating T/NT ratio,and with pain relief degree,⁸⁹Sr bremsstrahlung imaging for monitoring distribution of the bone-seeking radiopharmaceutical ⁸⁹Sr in body is feasibility.And it can preliminary decide prognosis of the patients.

Key words: Bone metastases, Strontium-89(⁸⁹Sr)radionuclide, Bremsstrahlung imaging, Radionuclide therapy