PURPOSE: The authors' purpose was to explore the association between mammographic findings and drainage patterns on lymphoscintigrams obtained during sentinel node procedures for breast carcinoma. MATERIALS AND METHODS: From July 1997 to March 2000, 132 patients with breast cancer who were included in a prospective mammography-pathology correlation and staging database were imaged 2 hours after perilesional injection of 1 mCi filtered (0. 22 microm) Tc-99m sulfur colloid (4 ml volume) before sentinel node procedures. RESULTS: Sixty-four percent of the scans showed axillary drainage only, 9% showed axillary and internal mammary drainage, and 4% revealed internal mammary drainage only. Twenty-three percent of scans showed no drainage. Of the patients who showed drainage, 17% showed drainage to the internal mammary basin, and 5% showed this exclusively. Internal mammary drainage was seen in 18% (10 of 57) of lateral, 21% (6 of 29) of medial, and 14% (1 of 7) of subareolar lesions (P = NS). No drainage was seen in 22% of patients with predominantly fatty mammographic parenchymal density (>50%) compared with only 8% of patients with predominantly dense (>50%) parenchyma (P < 0.05). Failure to show drainage was more common in women older than 50 years (P < 0.05). Axillary sentinel nodes were identified surgically in 73% of patients with negative scan findings. There was no significant association between scintigraphic drainage and mammographic soft tissue tumor size and appearance, histologic findings, or axillary node status. CONCLUSIONS: Dense mammographic parenchyma and age less than 50 years are associated with identification of lymphatic drainage on lymphoscintigrams performed before sentinel node procedures in 91% to 92% of patients. Internal mammary drainage, present in 18% of lateral and 21% of medial lesions, may direct therapy to include internal mammary lymph nodes.
PURPOSE: The authors' purpose was to explore the association between mammographic findings and drainage patterns on lymphoscintigrams obtained during sentinel node procedures for breast carcinoma. MATERIALS AND METHODS: From July 1997 to March 2000, 132 patients with breast cancer who were included in a prospective mammography-pathology correlation and staging database were imaged 2 hours after perilesional injection of 1 mCi filtered (0. 22 microm) Tc-99m sulfur colloid (4 ml volume) before sentinel node procedures. RESULTS: Sixty-four percent of the scans showed axillary drainage only, 9% showed axillary and internal mammary drainage, and 4% revealed internal mammary drainage only. Twenty-three percent of scans showed no drainage. Of the patients who showed drainage, 17% showed drainage to the internal mammary basin, and 5% showed this exclusively. Internal mammary drainage was seen in 18% (10 of 57) of lateral, 21% (6 of 29) of medial, and 14% (1 of 7) of subareolar lesions (P = NS). No drainage was seen in 22% of patients with predominantly fatty mammographic parenchymal density (>50%) compared with only 8% of patients with predominantly dense (>50%) parenchyma (P < 0.05). Failure to show drainage was more common in women older than 50 years (P < 0.05). Axillary sentinel nodes were identified surgically in 73% of patients with negative scan findings. There was no significant association between scintigraphic drainage and mammographic soft tissue tumor size and appearance, histologic findings, or axillary node status. CONCLUSIONS: Dense mammographic parenchyma and age less than 50 years are associated with identification of lymphatic drainage on lymphoscintigrams performed before sentinel node procedures in 91% to 92% of patients. Internal mammary drainage, present in 18% of lateral and 21% of medial lesions, may direct therapy to include internal mammary lymph nodes.