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Scientific Session 11 — Nuclear Medicine

Tuesday, May 2, 2017

Abstracts 2214-3136



3131. FDG PET/CT and PET/MRI in Staging Breast Cancer: Imaging Correlation With Tumor Characteristics

Airola K*,  Franceschi D,  Matthews R. Stony Brook University Medical Center, Stony Brook, NY

Address correspondence to R. Matthews (robert.matthews@stonybrook.edu)

Objective: The prognosis of breast cancer is determined by many factors including type of breast cancer, hormone receptor status, oncogene expression, and proliferative markers. We wish to correlate these factors to the severity and extent of metastatic disease as shown on staging FDG PET/CT or PET/MRI.

Materials and Methods: We retrospectively identified 50 patients with an initial diagnosis of breast cancer who underwent staging FDG PET/CT or PET/MRI from January 2014 to December 2015. All patients had PET at the time of diagnosis due to suspected metastatic disease. An experienced nuclear radiologist reviewed all images and reports. Size and maximum standardized uptake value (SUVmax) were calculated for all lesions. Electronic medical records were reviewed to look at patient demographics, tumor histology, and molecular markers.

Results: There were 50 female patients (mean age ± SD, 57.7 ± 13.9 years) including 12 patients who had PET/MRI examinations and 38 patients who had PET/CT examinations. Out of 39 patients with pathology results available, 33 had invasive ductal carcinoma, five had invasive lobular carcinoma, and one had ductal carcinoma in situ (DCIS). One patient had bilateral breast cancer. Molecular markers were noted for patients who were positive for HER2 (n = 8), estrogen receptor (n = 23), progesterone receptor (n = 17), and Ki-67 (n = 27). Twelve patients had distant metastases, and all but one had invasive ductal carcinoma. Imaging findings reported 31 PET-positive lymph nodes, eight bone metastases, six gastrointestinal metastases, one CNS metastases, one uterine metastasis, and five lung metastases. There was no statistical correlation between positive molecular markers and distant metastases. Younger patients (< 57 years) had a higher SUVmax in primary breast lesions (p = 0.0798) and higher SUV in metastatic lesions (p < 0.028) compared with older patients. Invasive lobular primary breast lesions had lower SUVmax (mean SUV, 2.4) compared with the invasive ductal cancer lesions (mean SUV, 10.7) (p < 0.0001).

Conclusion: Correlation of histology with FDG PET/CT and PET/MRI findings leads to better evaluation of tumor burden. This knowledge will help identify specific imaging findings related to tumor histology. Patients less than 57 years old who are diagnosed with breast cancer have a higher risk for aggressive tumors based on PET imaging. This knowledge will help clinicians and radiologists better diagnose, understand, and ultimately treat breast cancer.