Discrepancy between [18F]-FES and [18F]-FDG PET/CT in ER-positive breast cancer with oesophageal metastasis

Excerpt

A 79-year-old woman with recurrent invasive lobular carcinoma (ILC) of the right breast underwent right mastectomy with right axillary node dissection, radiotherapy at the right chest wall, and letrozole. She presented with progressive dysphagia and requested for positron emission tomography/computed tomography (PET/CT) with [18F]-fluorodeoxyglucose (FDG) and [18F]-fluoroestradiol (FES). (a) Maximal intensity projection (MIP) images of [18F]-FDG (left) and [18F]-FES (right) revealed [18F]-FES-avid lesions in the mediastinal and right chest wall regions with low [18F]-FDG. (b) Axial images showed non-[18F]-FDG-avid circumferential soft tissue thickening of the oesophagus but intense [18F]-FES avidity. (c) A [18F]-FDG-avid soft tissue mass at the right chest wall yielded more intense [18F]-FES avidity with (d) non-[18F]-FDG-avid soft tissue thickening at the right anterior and lateral chest wall showed intense [18F]-FES avidity, supporting ER-positive oesophageal and right chest wall metastases. EGD with biopsy confirmed metastatic ILC (ER 80%). Her treatment plan was changed to systemic therapy combined with palliative oesophageal radiotherapy. …