The application of 18F-FDG PET/MR in postoperative metastasis and restaging of breast cancer

Introduction: To explore the value of 18F-FDG PET/MR systemic imaging in postoperative metastasis detection and restaging of breast cancer.

Methods: Retrospective analysis of PET/MR, PET/CT imaging in 94 patients with breast cancer after surgery. On the same day, the whole body 18F-FDG PET/CT imaging and PET/MR imaging were performed. The differences in detection rate and restaging between the two devices were compared with pathology and clinical diagnosis as the gold standard.

Results: In 94 patients with postoperative breast cancer, 51 patients with metastasis were found, with a total of 469 lesions, including 210 lymph node metastases, 35 lung and pleural metastases, 30 intrahepatic metastases, 11 intracerebral metastases, 5 adrenal metastases and 178 bone metastases. The detection rate of lymph node and adrenal metastasis by the two devices is consistent. PET/MR found 56 more metastases than PET/CT in 28 patients, with significant statistical differences (χ²=28.86, P<0.01); 20 lesions were PET_-MR positive but PET_-CT was negative, including 5 brain metastases and 15 liver metastases; In 36 lesions, PET intake was negative on both devices, but MR was diagnosed with metastasis, including 4 brain metastases, 5 liver metastases and 27 bone metastases. The detection rate of PET/MR for liver, brain and bone metastasis is significantly higher than that of PET/CT (χ²=30.00, 18.33, 29.22, P<0.01). PET/CT found 20 more lesions than PET/MR, with significant statistical differences(χ²=28.00, P<0.01), all of which were pulmonary metastasis; In 35 and medium-medium lung and pleural metastases, 10 lesions had obvious FDG uptake, 22 lesions had no significant uptake, and 3 pulmonary metastases were positive in PET_-MR, while PET_-CT showed Negative. Through PET/MR examination, 15 patients changed the staging of PET/CT, with significant statistical differences (χ²=16.30, P<0.01).

Conclusions: PET/MR has high value for postoperative metastasis and restaging of breast cancer. The detection rate for craniocerebral, liver and bone metastases is higher than PET/CT. Pulmonary lesions still need CT-assisted diagnosis.

• Download figure
• Open in new tab
• Download powerpoint