Objective: To compare retrospectively the role of (18)F-FDG SPECT-CT and conventional imaging in the detection of recurrence and metastases in postoperative breast cancer patients with elevated level of tumor markers, and to evaluate the impact of (18)F-FDG SPECT-CT on the management of breast cancer patients.
Methods: (18)F-FDG SPECT-CT was performed in 35 breast cancer patients with suspected recurrence based on elevated level of serum tumor markers. Chest, abdomen and pelvic CT were performed in all patients and whole-body bone scan was performed in only 21 patients. The final diagnosis of recurrent breast cancer was confirmed by either pathology or observation by imaging during the follow-up for more than 1 year.
Results: Among the 35 patients, the final diagnosis of recurrence or metastasis was established in 19 patients. Of the 114 sites of increased FDG uptake, 93 were interpreted as malignant and 21 as benign. On site-based analysis, the sensitivity, specificity, accuracy, positive and negative predictive values were 93.1%, 55.6%, 84.2%, 87.1% and 71.4%, respectively, for (18)F-FDG SPECT-CT, and 80.5%, 60.5%, 75.6%, 80.2% and 65.1%, respectively, for conventional imaging. On the patient-based analysis, the sensitivity, specificity, accuracy, positive and negative predictive values were 84.2%, 62.5%, 74.3%, 72.7% and 76.9%, respectively, for (18)F-FDG SPECT-CT, and 74.1%, 67.6%, 70.6%, 68.3% and 73.9%, respectively, for conventional imaging. The results of (18)F-FDG SPECT-CT led to changes in the subsequent clinical management of 40.0% of these patients.
Conclusion: In postoperative breast cancer patients with elevated level of tumor markers during the follow-up, (18)F-FDG SPECT-CT is more sensitive for detecting recurrence and metastases than conventional imaging.