The Use of Positron Emission Tomography in Response to Therapy

Therapy for breast cancer is currently undergoing significant change with the addition of targeted therapies, new modes of the delivery of radiation therapy, as well as the modification of axillary staging and extent of surgery. So too should the method of imaging and the approach to staging with imaging be undergoing a revolution. Positron emission tomography (PET), having finally burst onto the stage of diagnosis and treatment, now provides a metabolic biopsy and allows for staging using glucose labeled with a radioactive (positron) emitter. This technique not only allows us to completely stage the patient but also allows us to metabolically decide who is responding to therapy and who is not responding to therapy. It allows us to guide therapy through imaging without multiple invasive techniques or multiple imaging modalities. The article that follows provides a review of the best available data for using PET and PET with simultaneously acquired computed tomography (PET/CT).