18F-FES PET Has Added Value in Staging and Therapy Decision Making in Patients With Disseminated Lobular Breast Cancer.

Lobular breast cancer is the second most common type of invasive breast cancer. Lobular breast cancer lesions are often difficult to detect with conventional imaging because they tend to grow less cohesively than ductal cancer. These images represent 3 lobular breast cancer cases, in whom confirmation of metastatic disease would make the crucial difference between curative or noncurative treatment. Staging with conventional imaging, however, yielded equivocal results, and a biopsy was not feasible. In contrast, FES (16α-[F]fluoro-17β-estradiol) PET provided a decisive contribution to clinical decision making in these patients. This indicates that FES PET may have added value in relation to conventional staging.