Potential and pitfalls of sentinel node detection in breast cancer

Sonographic Assessment of Axillary Lymph Nodes After a Mammographically Recommended Breast Sonogram for Women 55 Years and Older: A Feasibility Study

Sonographic guidelines have been provided for assessing lymph nodes both in the axilla and other areas of the body. The objective of this study was to determine the feasibility of using sonography and Doppler to provide diagnostic nodal information for women 55 years and older. The authors conducted a retrospective longitudinal study of a group of women 55 years and older who provided their prior health histories, mammography, and sonogram results, as well as eventual pathology reports, to help establish the value of Doppler measurements, nodal dimensions, and subjective assessment data collected at the time of the breast sonogram. Each patient consented to allow 15 minutes of scanning of her axilla to evaluate three lymph nodes. Fifty-two women provided data points that were captured and compared to published guidelines, such as longitudinal/diameter (L/D) ratio, resistive index (RI), and Stavros's subjective grading scale. The longitudinal axis compared to the diameter of a node (L/D ratio), shape, and RI was statistically correlated with published guidelines. Sonographic measures and Doppler assessment of axillary lymph nodes are feasible, and continued research could result in a reliable set of parameters that could be used as an economical, noninvasive imaging technique for possible staging of women 55 years and older.

The efficacy of 99mTc-HIG for sentinel lymph node mapping in breast cancer patients

OBJECTIVE

To evaluate the efficacy of Tc-HIG on SLN identification in patients with early-stage breast cancer.

MATERIALS AND METHODS

Seventeen women (18 tumours) with early-stage breast cancer were included. On the day of the operation, 111 MBq Tc-HIG was injected around the tumour or biopsy scar in all patients. Subsequently, dynamic lymphoscintigraphic images were taken for 30 min. After this, static images were recorded at 15-20 min intervals until the SLN was visualized. Patients were taken to the operating room 2-4 h after radiopharmaceutical injection. Before the incision, 5 ml of isosulfan blue dye solution was injected peritumourally in all subjects. Aided by blue dye and gamma probe SLN detection was done during the operation.

RESULTS

In 17/18 tumours, SLN was detected with Tc-HIG lymphoscintigraphy. The mean visualization time for axillary SLNs was 49.94+/-11.25 min and for internal mammary SLNs was 52.50+/-10.60 min. In 15 of the tumours, only one SLN was detected in the axillary region. However, in two tumours, SLNs were found in both axillary and internal mammary regions. With blue dye mapping, axillary SLNs were found in 17/18 tumours. With the application of intraoperative gamma probe, all axillary and internal mammary SLNs were detected in 18 tumours.

CONCLUSION

We conclude that Tc-HIG may be a suitable agent for SLN detection by lymphoscintigraphy and intraoperative gamma probe application in early-stage breast cancer patients.

[Optimization of staging in colon cancer using sentinel lymph node biopsy]

Routine determination of the nodal status in colon cancer is strongly dependent on the individual quality and technique of histopathological assessment and surgical lymph node dissection. We evaluated whether sentinel lymph node biopsy (SLNB) could contribute to an improvement in staging. At least one SLN (median n=2) was detected (detection rate 84%) in each of 38 of 45 patients with primary colon cancer. Ten of these 38 were found to have lymph node metastases by HE staining (26%), six of them in the SLN. Nine of the 28 patients that were initially nodal-negative by HE revealed one micrometastasis and eight cases of isolated tumor cells by immunohistochemical (IHC) staining (32% upstaging response). Including the IHC-positive cases, 19 of the 38 patients were nodal-positive (50%), 15 of them with tumor-infiltrated SLN (overall sensitivity of SLNB 79%). Using the dye method, SLNB is clinically practicable and leads in the majority of the patients to the detection of SLN. The selective, intensified histopathological assessment of SLN identifies small tumor cell deposits in a relevant percentage of patients with little and clinically practicable effort.

Sentinel lymph node identification and sampling in women with early breast cancer using 99m Tc labelled dextran 500 and patent blue V dye

The status of the homolateral axillary lymph nodes is still the most important prognostic factor in early stage breast cancer. The information obtained from the pathological examination of the lymph nodes guides is of critical importance in the decision process regarding the use of postoperative adjuvant therapy. However, lymph node axillary dissection can be followed by significant locoregional morbidity. The sentinel lymph node (SLN) technique was developed as a means of avoiding the full exploration of the axilla and consists in the identification of the first lymph node in the lymphatic drainage system of the breast tumour in the homolateral axilla. It has been demonstrated that the status of the SLN is highly predictive for the presence or absence of tumour involvement in the remaining lymph nodes in the axilla. In this study we evaluated the SLN technique using both 99mTc labelled dextran 500 and patent blue V dye in relation to the classical lymph node resection a series of 56 women with early breast cancer who attended the Breast Unit of the Academic Hospital of the Federal University of Rio Grande do Sul, Brazil. To our knowledge this is the first report in the literature of the utilization of 99mTc dextran 500 for the SLN technique. As there are no similar commercially available dedicated radiopharmaceuticals labelled for use in lymphoscintigraphy studies, we report on an effective method to label dextran 500 with 99mTc which proved to be simple, inexpensive and yielded similar results for SLN identification compared with those given in the literature. The median age of the patients was 57 years (range 32-82 years). Seventeen patients were age 50 years or less, and 39 patients were older than 50 years. The median tumour size was 2.0 cm (range 0.8-7.0 cm). The mapping of the SLN was possible in all cases during the transoperative period by using a hand-guided gamma probe and a blue dye. A median of 2.0 (range 1-5) SLN were excised per patient. The median of axillary lymph nodes excised per patient was 21 (range 10-36). The calculated sensitivity and specificity of the method were 95.6% and 100%, respectively. The negative predictive value and overall accuracy were 97% and 98.2%, respectively. In conclusion, the SLN technique was feasible and produced similar positive results as previously reported in the literature.