Background: The aim of this study was to investigate the diagnostic value of FDG PET in the follow-up for breast cancer in disease-free patients and patients suspected of having recurrent or metastatic disease. As a single imaging tool, PET can be compared with the conventional diagnostic means used for different examination sites.
Patients and methods: A total of 73 PET studies were carried out on 57 patients who had been diagnosed as having breast cancer. Sixteen patients had two PET scans. Thirty-eight scans (52.%) were performed in a follow-up setting. Thirty-five PET scans were performed in patients suspected of having recurrent disease or elevated tumor marker. Depending on the region of suspicion, conventional imaging included computed tomography, magnetic resonance imaging, chest X-ray, ultrasound and X-ray. All the patients in our study were followed-up for a period of 12 months.
Results: PET correctly identified metastatic or recurrent disease in 25 out 27 cases of clinical suspicion. In patients examined because of elevated tumour marker CA 15-3, PET was able to detect recurrence or metastatic disease in six of the eight patients. The absence of disease was correctly diagnosed by PET in 35 out of 38 scans in 24 patients in the follow-up for breast cancer. The overall sensitivity and specificity for PET was 80.6% and 97.6%, respectively. On the basis of a yearly rate of disease progression of 5-8%, the mean positive predictive value was 74.5% and the mean negative predictive value 98.3%.
Conclusion: PET has been shown to have impact on the staging and management of recurrent or metastatic breast cancer in cases of suspicion and in a follow-up setting. The current oncological situation can be clarified with a single basic imaging modality.