PET/CT Assessment of Treatment Response for Patients Known to Have Metastatic Breast Cancer

Background: Breast cancer is worldwide common disease. Early detection of metastatic breast cancer is important to improve mortality related disease. Objective: To evaluate the response of known breast cancer metastases to treatment by PET/CT. To evaluate also the whole performance of PET/CT in detecting local recurrence and metastases in those patients. Patients and Methods: This prospective study included 16 female patients (with age ranging from 38 to 63 years and mean age 50.5 years). All patients are well known to have metastatic breast cancer. The patients received combined courses of treatment; surgery, chemotherapy, radiotherapy and/or hormonal therapy. PET examination and contrast enhanced CT examinations were done to all patients on combined PET/CT system in the same setting. Fused images were reviewed on workstation and treatment response of the different types of metastases and new recurrences were recorded. The PET/CT results were finally compared to the histopathological data and clinical follow-up. The treatment response was assessed. Results: Local recurrence was the final diagnosis with distant metastases in 2 patients, distant metastases without local recurrence was confirmed in 11 patients and negative for recurrence or distant metastases in three patients. The overall diagnostic accuracy of PET/CT was 90.6% with sensitivity of 86% and specificity of 92.4%. The positive predictive value was 87.5% and negative predictive value was 92.5%. Regarding the response to treatments was complete response in 2 patients, partial response in 2 patients, mixed response in 6 patients, no response (stationary course) in 2 patients and tumour progression in 4 patients. Conclusion: PE/CT is a valuable examination technique for follow-up and assessment of treatment response in metastatic breast cancer.