An understanding of prognostic factors in breast cancer is imperative for guiding patient care. Increased tumor size and more advanced nodal status are established independent prognostic factors of poor outcomes and are incorporated into the American Joint Committee on Cancer (AJCC) TNM (primary tumor, regional lymph node, distant metastasis) staging system. However, other factors including imaging findings, histologic evaluation results, and molecular findings can have a direct effect on a patient's prognosis, including risk of recurrence and relative survival. Several microarray panels for gene profiling of tumors are approved by the U.S. Food and Drug Administration and endorsed by the American Society of Clinical Oncology. This article highlights prognostic factors currently in use for individualizing and guiding breast cancer therapy and is divided into four sections. The first section addresses patient considerations, in which modifiable and nonmodifiable prognostic factors including age, race and ethnicity, and lifestyle factors are discussed. The second part is focused on imaging considerations such as multicentric and/or multifocal disease, an extensive intraductal component, and skin or chest wall involvement and their effect on treatment and prognosis. The third section is about histopathologic findings such as the grade and presence of lymphovascular invasion. Last, tumor biomarkers and tumor biology are discussed, namely hormone receptors, proliferative markers, and categorization of tumors into four recognized molecular subtypes including luminal A, luminal B, human epidermal growth factor receptor 2-enriched, and triple-negative tumors. By understanding the clinical effect of these prognostic factors, radiologists, along with a multidisciplinary team, can use these tools to achieve individualized patient care and to improve patient outcomes. ©

As digital breast tomosynthesis (DBT) becomes widely used, radiologists must understand the basic principles of (a) image acquisition, (b) artifacts, and (c) quality control (QC) that are specific to DBT. Standard acquisition parameters common to both full-field digital mammography (FFDM) and DBT are combinations of x-ray tube voltage, current exposure time, and anode target and filter combinations. Image acquisition parameters specific to DBT include tube motion, sweep angle, and number of projections. Continuous tube motion or x-ray emission decreases imaging time but leads to focal spot blurring when compared with step-andshoot techniques. The sweep angle and number of projections determines resolution. Wider sweep angles allow greater out-of-plane (z-axis) resolution, improving visualization of masses and architecture distortion. A greater number of projections increases in-plane or x-y axis resolution, improving visualization of microcalcifications. Artifacts related to DBT include blurring-ripple, truncation, and loss of skin and superficial tissue resolution. Motion artifacts are difficult to recognize because of inherent out-of-plane blurring. To maintain optimal image quality and an "as low as reasonably achievable" (ALARA) radiation dose, regular QC must be performed. DBT is considered a new imaging modality; therefore, breast imaging facilities are required to obtain a separate certification in addition to that in FFDM, and all personnel (radiologists, technologists, and medical physicists) are mandated to complete initial DBT training and maintain appropriate continuing medical education credits. ©

I planar imaging in patients who 1) had histologically proven DTC, 2) were suspected to have metastatic DTC (e.g., elevated Tg, positive recent fine-needle aspiration cytology, suspicious enlarging mass), and 3) had 131

Various studies have compared the detection of functioning residual thyroid tissue after thyroidectomy using radioiodine whole-body (WB) imaging following preparation of patients with injections of recombinant human thyroid-stimulating hormone (rhTSH) and thyroid hormone withdrawal (THW). However, metastases may have radiopharmacokinetics different from normal thyroid tissue. The objective of this study was to evaluate these 2 methods of patient preparation for the detection of metastases from differentiated thyroid cancer (DTC) using 131 I WB imaging and 124 I PET. Methods: A prospective study approved by the institutional review board was conducted at Washington Hospital Center from 2006 to 2010 recruiting patients who had DTC, were suspected of having metastasis from DTC (e.g., elevated thyroglobulin level without thyroglobulin antibodies, positive results on recent fine-needle aspiration, suspected enlarging mass, and abnormal findings suggesting metastasis on a diagnostic study) and were referred for 131 I WB dosimetry. All patients subsequently underwent both 131 I WB imaging and 124 I PET performed using the same preparation. All foci of uptake identified on these scans were categorized in a masked manner by consensus of 2 physicians in the following manner: 1, definite physiologic uptake or artifact; 2, most likely physiologic uptake or artifact; 3, indeterminate; 4, most likely locoregional metastases in the neck bed; 5, most likely distant metastases; or 6, definite distant metastases. Foci categorized as 4, 5, and 6 were considered positive for functioning metastases. Results: Of 40 patients evaluated, 24 patients were prepared with rhTSH and 16 with THW. No statistical difference was noted between the 2 groups for any of the parameters evaluated, including serum thyroglobulin. The percentages of patients with positive foci detected on the rhTSH 131 I and THW 131 I WB scans were 4% (1/24) and 63% (10/16), respectively (P , 0.02). The number of foci detected on the rhTSH 131 I and THW 131 I WB scans were 2 and 58, respectively (P , 0.05). When 124 I PET was used for imaging, the percentages of patients with foci detected on the rhTSH and THW scans were 29% (7/24) and 63% (10/16), respectively (P , 0.03). The number of foci detected on the rhTSH and THW scans were 17 and 117, respectively (P , 0.03). Conclusion: Significantly more foci of metastases of DTC may be identified in patients prepared with THW than in patients prepared with rhTSH.

Professionals who specialize in breast imaging may be the first to initiate the conversation about genetic counseling with patients who have a diagnosis of premenopausal breast cancer or a strong family history of breast and ovarian cancer. Commercial genetic testing panels have gained popularity and have become more affordable in recent years. Therefore, it is imperative for radiologists to be able to provide counseling and to identify those patients who should be referred for genetic testing. The authors review the process of genetic counseling and the associated screening recommendations for patients at high and moderate risk. Ultimately, genetic test results enable appropriate patient-specific screening, which allows improvement of overall survival by early detection and timely treatment. The authors discuss pretest counseling, which involves the use of various breast cancer risk assessment tools such as the Gail and Tyrer-Cuzick models. The most common high-and moderaterisk gene mutations associated with breast cancer are also reviewed. In addition to BRCA1 and BRCA2, several high-risk genes, including TP53, PTEN, CDH1, and STK11, are discussed. Moderate-risk genes include ATM, CHEK2, and PALB2. The imaging appearances of breast cancer typically associated with each gene mutation, as well as the other associated cancers, are described. ©