Internal mammary lymph node drainage patterns in patients with breast cancer documented by breast lymphoscintigraphy.

BACKGROUND: Metastases to internal mammary lymph nodes (IMN) may occur in patients with breast cancer and may alter treatment recommendations. The purpose of this study was to identify the frequency of IMN drainage in patients undergoing breast lymphoscintigraphy and sentinel lymph node dissection (SLND). METHODS: The combined technique of peritumoral injection of radiocolloid and Lymphazurin blue for SLND was performed on 220 patients. All patients underwent preoperative lymphoscintigraphy before SLND. Lesion location by quadrant included: 110 upper outer (UOQ), 49 lower outer (LOQ), 30 upper inner (UIQ), 24 lower inner (LIQ), and 7 central. RESULTS: Drainage to any nodal basin was observed in 184 of 220 patients (84%). IMN drainage was documented in 37 of 220 (17%) of patients. IMN drainage without evidence of axillary drainage occurred in 2 of 220 patients(1%). Drainage to the IMN based on quadrant location of the lesion was as follows: UOQ, 10%; LOQ, 27%; UIQ, 17%; LIQ, 25%; and central, 29%. CONCLUSIONS: Internal mammary lymph node drainage shown by breast lymphoscintigraphy is common. Tumors in all quadrants may drain to IMNs, although drainage is significantly more common from quadrants other than the UOQ. Further studies are needed to determine whether lymphoscintigraphy drainage patterns identify patients at the highest risk for IMN metastases who may benefit from radiotherapy.

Increased false negative sentinel node biopsy rates after preoperative chemotherapy for invasive breast carcinoma.

BACKGROUND: Sentinel lymph node dissection (SLND) has been a promising new technique in breast carcinoma staging, but could be unreliable in certain patient subsets. The current study assessed whether age, preoperative chemotherapy, tumor size, and/or previous excisional biopsy influenced the identification of sentinel nodes (SLNs) or the reliability of a node-negative SLND in predicting a node negative axilla. METHODS: Eighty-two patients who had clinically negative axillae underwent SLND followed by Level I/II axillary lymph node dissection (ALND). SLNDs were performed using both technetium-99m (Tc-99m) labeled colloid and isosulfan blue dye. SLNs were analyzed by hematoxlyin and eosin and immunocytochemical techniques. RESULTS: SLNs were successfully identified in 80% of patients. Mapping success was decreased among postmenopausal women but was not influenced by preoperative chemotherapy, large tumor size, or previous excisional biopsy. Of the 31 successfully mapped, node positive patients, 5 had false negative (FN) SLNDs (overall FN rate = 16%). Of the 9 successfully mapped patients who had received preoperative chemotherapy and had positive axillary nodes, 3 had FN SLND (FN rate = 33%). The presence of clinically positive lymph nodes before chemotherapy did not predict which patients would have a subsequent FN SLND. T3 tumor size, but not previous excision, was associated significantly with increased FN rate, although the FN rate for previous excision was 11%. No FN SLND occurred with T1/T2 tumors that were not excised previously and had not received preoperative chemotherapy. CONCLUSIONS: Preoperative chemotherapy was associated with an unacceptably high FN rate for SLND. While larger tumor size also was associated with FN SLND, this effect might have been due to preoperative chemotherapy use in these patients. Small sample size precluded determining whether excisional biopsy before mapping increased FN SLND rates independently.

Sentinel lymph node mapping for breast cancer: analysis in a diverse patient group.

PURPOSE: To evaluate sentinel lymph node mapping in patients with breast cancer. MATERIALS AND METHODS: Sixty-two patients with breast cancer scheduled to undergo axillary nodal dissection underwent scintigraphic localization of sentinel lymph nodes with filtered technetium 99m sulfur colloid. At surgery, isosulfan blue was injected. Sentinel nodes were identifiable by blue color and by radioactivity with hand-held gamma probe. Results were analyzed statistically. RESULTS: A sentinel lymph node was identified in 49 patients (79%). Lymph nodes were positive for metastatic disease in 26 patients (42%). The mapping success rate was 78% (n = 21) in the 27 patients with no prior surgery, 78% (n = 18) in the 23 patients with prior surgery, and 86% (n = 12) in the 14 patients with prior chemotherapy. Axillary nodes were positive in 11 (41%) of the 27 patients with no prior intervention, six (26%) of the 23 patients with prior surgery, and 10 (71%) of the 14 patients with prior chemotherapy. There were no false-negative findings in patients without prior intervention. Four patients with positive nodes had false-negative sentinel nodes. CONCLUSION: Sentinel lymph node mapping and biopsy without axillary dissection is appropriate in patients with breast cancer who have not undergone prior intervention. Further study is necessary to ascertain the accuracy of the procedure for patients who have undergone presurgical chemotherapy or previous excisional biopsy.

Technical aspects of sentinel node lymphoscintigraphy for breast cancer.

OBJECTIVE: A significant morbidity risk is associated with axillary nodal dissections for breast cancer. Many treatment decisions are based on axillary nodal status. Lymphatic mapping and sentinel node biopsy have been investigated to determine if the histology of the sentinel node reflects the remaining lymph node basin. We describe the technical aspects of sentinel node lymphoscintigraphy for breast cancer. METHODS: Ninety-three patients had lymphoscintigraphy for breast cancer. Patients with palpable lesions had 4 concentric injections around the site and lesions requiring localization had injections made through tubing connected to the localizing wire introducer needle. Immediate static images were acquired and the sentinel node was marked for surgery. Marks were reverified using a handheld gamma probe. RESULTS: Lymph nodes were visualized by lymphoscintigraphy in 87% of cases. Time to visualization of lymph nodes ranged from 1-120 min with a mean of 28 min. An average of 1.5 nodes were visualized. The overall success rate for identifying the sentinel node at time of surgery was 85%. CONCLUSION: We conclude that lymphoscintigraphy for breast cancer is a detailed procedure that requires coordination with radiology and surgery teams to ensure proper identification of sentinel lymph nodes.

Monitoring the response of patients with locally advanced breast carcinoma to neoadjuvant chemotherapy using [technetium 99m]-sestamibi scintimammography.

BACKGROUND: Mammographic and physical examination assessments of the response of locally advanced breast carcinoma (LABC) to neoadjuvant therapy have been shown to be inaccurate. The authors studied the feasibility and accuracy of [technetium 99m]-sestamibi (MIBI) for monitoring the response of patients with LABC to neoadjuvant chemotherapy. METHODS: Patients receiving neoadjuvant chemotherapy for LABC underwent prone lateral scintimammography before therapy, after 2 months of therapy, and close to the completion of chemotherapy (presurgery) if chemotherapy continued for >3 months. Images were analyzed both qualitatively and quantitatively using the lesion-to-normal breast MIBI uptake ratio (L:N). Imaging results were compared with the clinical response and the pathologic response as determined from the posttherapy surgical specimen. RESULTS: A total of 32 patients (29 who were assessable for primary tumor response and 28 who were assessable for lymph node response) were included in the study. The mean change in the primary tumor L:N MIBI uptake ratio after 2 months of chemotherapy was -35% for clinical responders and +17% for nonresponders (P<0.001). Patients achieving a pathologic primary tumor macroscopic complete response (CR) had a mean change in uptake on the presurgical scan of -58% versus -18% for patients with a partial response (P<0.005). A decrease of > or =40% in the MIBI uptake ratio identified CRs with 100% sensitivity and 89% specificity. Pretherapy imaging predicted axillary lymph node metastases in 85% of patients ultimately found to have > or =1 positive lymph nodes at surgery, but was less accurate in identifying residual lymph node disease after therapy (55% sensitivity and 75% specificity). CONCLUSIONS: MIBI imaging accurately assessed the response to neoadjuvant chemotherapy in patients with LABC. Further studies are needed to determine the role of MIBI in this group of patients.

Utility and reproducibility of semiquantitative analysis of sestamibi breast images.

UNLABELLED: Technetium-99m-sestamibi scintimammography has been shown to be a useful diagnostic test in the detection of breast cancer. The purpose of this study was two-fold to: (a) evaluate semiquantitative indices of tracer uptake in lesions and determine if they are helpful in distinguishing benign from malignant breast lesions; and (b) test the reproducibility of these measures of sestamibi uptake in breast images. METHODS: Prone lateral planar imaging was performed on 27 patients after intravenous injection of 20-30 mCi 99mTc-sestamibi. Data were analyzed by creating three regions of interest (ROIs) over designated areas: lesion, normal breast and right chest wall. Lesion-to-normal (L:N) and lesion-to-chest wall (L:CW) ratios were calculated for each patient. Reproducibility was assessed by having two independent observers draw ROIs (interobserver) and one observer draw two independent sets of ROIs (intraobserver). RESULTS: L:N and L:CW ratios were significantly different for malignant versus benign lesions (p < 0.001 for both ratios). Intraobserver and interobserver reproducibility showed good correlation with r = 0.98 (L:CW ratio). CONCLUSION: Semiquantitative analysis of sestamibi breast imaging results in reproducible uptake ratios that may be helpful in objectively interpreting imaging results.