Evaluation of the role of ^99mTc-MDP bone scan for follow-up and assessment of the treatment response in metastatic breast cancer

Bone metastasis is common in breast cancer. The aim of this study was to re-evaluate the role of ^99mTc-MDP bone scan for follow-up and assessment of the treatment response in metastatic breast cancer. Radionuclide bone scan of 537 female breast cancer patients were performed in our department from September 2011 to august 2013. The results of these baseline scans were correlated with T stages of the disease. Follow-up bone scans of 120 patients were performed. The data was retrospectively analyzed. While analyzing the results of follow-up scans, identification of new lesions and extent and severity of the existing lesions were taken into consideration to evaluate treatment response. Out of 537 patients who underwent the baseline bone scan, one had carcinoma in situ, 23 of them had T1 lesion, 158 ladies had T2, 101 women had T3 and 158 ladies had T4 lesions.T staging was not known in 96 patients. Bone metastases were detected in 96 patients and bone scan was normal in rest 441 ladies. More than 75 % patients who had a positive bone scan were asymptomatic Incidence of positive scans was higher in locally advanced disease (35% in patients with T3 and T4 lesions against 23% for combined CIS,T1, T2 lesions). Multiple metastases was noticed in 72 patients and 24 patients had solitary lesion. Vertebrae were found to be the commonest site of metastases (76 out of 374 total bone lesions).50 out of 96 patients had follow-up bone scan. Stable disease was noticed in 16 patients (32%). Disease progressed in 24 patients (48%)and there was partial interval treatment response in 10 (20%). patients.75 out of 441 patients who had an initially normal bone scan underwent a follow-up bone scan.16 out of 75 (21.33%) patients had metastases in the followup scan---7 of them had solitary lesion and 9 women had multiple metastases. In this study the importance of ^99mTc-MDP bone scan for follow-up and assessment of the treatment response in metastatic breast cancer has been reiterated. This is a simple and robust technique which can objectively evaluate the response to treatment and also for follow-up of patients with an initially normal baseline scan. (author)