Dye-Guided Sentinel Lymphadenectomy in Clinically Node-Negative and Node-Positive Breast Cancer Patients

Conservative Axillary Surgery May Prevent Arm Lymphedema without Increasing Axillary Recurrence in the Surgical Management of Breast Cancer

Axillary lymph node dissection (ALND) has been associated with postoperative morbidities, including arm lymphedema, shoulder dysfunction, and paresthesia. Sentinel lymph node (SLN) biopsy emerged as a method to assess axillary nodal status and possibly obviate the need for ALND in patients with clinically node-negative (cN0) breast cancer. The majority of breast cancer patients are eligible for SLN biopsy only, so ALND can be avoided. However, there are subsets of patients in whom ALND cannot be eliminated. ALND is still needed in patients with three or more positive SLNs or those with gross extranodal or matted nodal disease. Moreover, ALND has conventionally been performed to establish local control in clinically node-positive (cN+) patients with a heavy axillary tumor burden. The sole method to avoid ALND is through neoadjuvant chemotherapy (NAC). Recently, various forms of conservative axillary surgery have been developed in order to minimize arm lymphedema without increasing axillary recurrence. In the era of effective multimodality therapy, conventional ALND may not be necessary in either cN0 or cN+ patients. Further studies with a longer follow-up period are needed to determine the safety of conservative axillary surgery.

Axillary surgery for breast cancer: past, present, and future

In breast cancer surgery, there has been a major shift toward less invasive local treatment. Although axillary lymph node dissection (ALND) was an integral part of surgical treatment for breast cancer, sentinel lymph node (SLN) biopsy was developed as an accurate method for axillary staging. ALND can be avoided not only in patients with negative SLNs but also in those with one or two positive SLNs receiving breast and/or axillary radiation. On the other hand, ALND has remained the standard treatment for patients with clinically positive nodes. However, axillary reverse mapping (ARM) was developed to map and preserve arm lymphatic drainage during ALND and/or SLN biopsy. This procedure allowed reduction of the rate of arm lymphedema without increasing axillary recurrence, although patients receive postoperative chemotherapy and high-risk patients undergo axillary radiation. Standard ALND may not be necessary even for patients with clinically positive nodes who receive axillary radiation and systemic therapy. Thus, the extent of axillary surgery in breast cancer has been decreased with increased use of systemic and radiation therapy.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

BACKGROUND

In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS

We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS

There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS

The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

Avoidance of axillary lymph node dissection in selected patients with node-positive breast cancer

AIMS

Currently, it is standard practice to avoid ALND in patients with negative SLN, whereas this procedure is mandated for those with positive SLN. However, there has been some debate regarding the necessity of complete ALND in all patients with positive SLN. This review article discusses the issues related to eliminating the need for ALND in selected patients with positive nodes.

METHODS

A review of the English language medical literature was performed using the MEDLINE database and cross-referencing major articles on the subject, focusing on the last 10 years.

RESULTS

Currently, complete ALND is mandated in patients with SLN macrometastases as well as those with clinically positive nodes. It is not clear whether SLN biopsy is appropriate for axillary staging in patients with initially clinically positive nodes (N1) that become clinically node-negative (N0) after neoadjuvant chemotherapy. Although there is debate regarding whether ALND should be performed in patients with micrometastases in the SLN, it seems premature to abandon ALND in clinical practice. Moreover, it remains unclear whether it is appropriate to avoid complete ALND in patients with ITC-positive SLN alone.

CONCLUSIONS

In the absence of data from randomised trials, the long-term impact of SLN biopsy alone on axillary recurrence and survival rate in patients with SLN micrometastases as well as those with ITC-positive SLN remains uncertain. These important issues must be determined by careful analysis of the results of ongoing clinical trials.

President’s Address

In breast cancer surgery, there has been a major shift toward less invasive local treatment: from extended or radical mastectomy to modified radical mastectomy, from modified radical mastectomy to breast conserving therapy, and from routine axillary lymph node dissection to sentinel lymph node biopsy. Many breast surgeons have experienced an evolutionary progression of surgical management of breast cancer. However, there is an increasing demand for minimally invasive and non-surgical treatment methods for patients with small breast cancer. Radiofrequency (RF) ablation is the most promising among non-surgical ablation techniques in the treatment of breast cancer, although it is still in the investigative stage. Nevertheless, surgery still plays an integral role in the treatment of breast cancer, because local therapy is important for enhancing survival in the presence of systemic therapy. In clinical practice, surgical oncologists must individualize treatments, selecting a surgical or non-surgical procedure that provides the best local control, does not compromise the chances of cure, and achieves the best cosmetic results.

Sentinel node detection in breast cancer using contrast-enhanced sonography with 25% albumin--Initial clinical experience

PURPOSE

To determine the clinical usefulness of a sentinel lymph node (SLN) identification technique using contrast-enhanced sonography (CEUS) with 25% albumin.

METHODS

The subjects were 23 women with breast cancer. Each was injected subcutaneously with 5 ml of 25% albumin solution as a negative contrast agent directly superficial to the breast tumor. The area was massaged, and the inferior axillary hairline was examined continuously using gray-scale sonography with a 7.5- or 10-MHz transducer. Any contrast-enhanced lymph node was considered a CEUS-detected SLN, was differentiated from other level I and II nodes, and was resected and pathologically assessed.

RESULTS

In all 23 patients, 1 or 2 CEUS-detected SLNs (mean, 1.3 SLNs) were identified. Their sizes ranged from 5 mm to 25 mm (mean, 11.3 mm), and their depths (from the skin surface) ranged from 5mm to 20 mm (mean, 12.6 mm). Pathologic examination revealed a metastasis in 5 of the 23 patients, all in CEUS-detected SLNs.

CONCLUSION

In a clinical study using CEUS with 25% albumin, contrast-enhanced nodes were identified in all subjects. The pathologic findings suggested that any metastatic nodes observed were SLNs, indicating that this technique may represent a new modality for SLN identification.

Reliability of sentinel lymph node biopsy with squamous cell carcinoma of the oral cavity

OBJECTIVES

Although sentinel lymph node biopsy (SLNB) may reduce surgery-related complications related to unnecessary lymph node dissection and is now widely used for many patients with cutaneous melanoma and breast cancer, its use for oral cancer patients remains controversial. One of the main reasons for the reluctance to initiate SLNB for oral cancer is that the frequency of skip metastasis has not been clarified. The objectives of this study are to examine the frequency of skip metastasis and to evaluate SLNB for oral cancer.

STUDY DESIGN

To shed light on these concerns, we first conducted a retrospective study of 296 patients with squamous cell carcinoma of the oral cavity who underwent neck dissection. Next, the accuracy of lymph node biopsy with and without detecting sentinel lymph node was examined.

RESULTS

Ten patients showed skip neck metastasis in the level III-V region without level I-II involvement. Of these patients, 7 underwent neck dissection when their initially N0 neck progressed to N+, 2 underwent neck dissection when local recurrence occurred, and only 1 underwent surgery as an initial therapy. Most patients who underwent neck dissection as the initial therapy showed skip metastasis. Intraoperative lymph node biopsy without any attempt to detect sentinel lymph nodes by means of blue dye or lymphoscintigraphy was performed on 68 patients with oral cancer. Sixty-one (90%) were diagnosed correctly, whereas 7 diagnosed as N- actually had neck metastasis. SLNB with blue dye was performed on 21 patients. In 17 of them, sentinel lymph node was easily detected, resulting in a correct diagnosis for 16 patients (94%), while 1 with a false negative result actually had micrometastasis.

CONCLUSION

These findings seem to suggest that SLNB is useful and can be applied to patients with oral cancer who undergo surgery as the initial therapy.

Follow-up of cases with false-negative pathologic sentinel nodes in breast cancer

BACKGROUND

The clinical practice of sentinel lymph node biopsy for breast cancer patients started in 1999 in our hospital, to obviate unnecessary axillary lymph node dissection. The present study examines the pathological false-negative cases on intraoperative sentinel lymph node investigations and evaluates their outcomes.

METHODS

The subjects consisted of 183 cases with clinically node-negative breast cancer who had undergone sentinel node biopsy. When the sentinel node was noted to contain malignant cells intraoperatively, a complete axillary lymph node dissection was performed subsequently. The patients with tumor free sentinel nodes underwent no further axillary surgery. The pathological false-negative cases in this series were defined as patients with lymph node involvement which was revealed postoperatively, despite negative intraoperative sentinel node examinations. After these surgeries and/or adjuvant therapies, interval clinical evaluations were performed for all patients.

RESULTS

Intraoperative diagnosis of the sentinel node was 96.2% accurate compared with the results of permanent sections. There were six pathological false-negative cases, a false-negative rate of 4.1%, all of which had only micrometastasis. Five cases received systemic adjuvant therapy and have been disease-free, however, one patient who refused further therapy developed infraclavicular lymph node metastasis two years after surgery.

CONCLUSIONS

In the management of the patients with postoperatively revealed sentinel node micrometastasis, systemic adjuvant therapies might reduce local relapse without secondary lymph node dissection.

Sentinel lymph nodes with technetium-99m colloidal rhenium sulfide in patients with esophageal carcinoma

BACKGROUND

The authors assessed the detection of sentinel lymph nodes in patients with esophageal squamous cell carcinoma (SCC) using technetium-99m colloidal rhenium sulfide. They studied whether an analysis of sentinel lymph nodes using cytokeratin (CK) immunohistochemistry increased the accuracy of staging.

METHODS

The authors observed 25 patients with thoracic esophageal carcinomas who underwent radical esophagectomy. The day before surgery, technetium-99m colloidal rhenium sulfide was injected into the submucosa at four sites around the primary tumor. Lymphoscintigraphy was performed. Esophagectomy and regional lymph node dissection were performed 17 hours after the technetium-99m injection. After surgery, the resected lymph nodes were evaluated by CK staining.

RESULTS

Lymphoscintigraphy detected sentinel lymph nodes in 92% of the patients (23 of 25 patients). The accuracy of sentinel lymph node was 91.3% (21 of 23 patients), the sensitivity was 86.7% (13 of 15 patients), and the false-negative rate was 8.7% (2 of 23 patients). A comparison of the number of sentinel lymph nodes and clinicopathologic factors showed that there was a significant association between the number of sentinel lymph nodes and lymph node status (P < 0.01), pathologic stage (P < 0.05), and the number of metastatic lymph nodes (P < 0.05). Occult metastasis was detected by CK staining in 14 (56%) of the 25 patients and in 23 (1.7%) of 1406 lymph nodes. Because the 2 false-negative (sentinel lymph node-negative and nonsentinel lymph node-positive) patients who had occult metastases in the sentinel lymph nodes, the accuracy of sentinel lymph node evaluation using CK staining was 100% (23 of 23).

CONCLUSIONS

Lymphatic mapping with technetium-99m colloidal rhenium sulfide was used to identify the lymphatic basin and was feasible in patients with esophageal SCC. An analysis of sentinel lymph nodes using CK immunohistochemistry increased the accuracy of sentinel lymph node.

Combination of subareolar blue dye and peritumoral RI for sentinel lymph node biopsy

BACKGROUND

The identification rate of sentinel lymph nodes (SLNs) is variable because numerous different methods employing different tracers have been used for sentinel lymph node detection. The aim of this study was to determine the optimal technique for sentinel lymph node biopsy (SLNB).

METHODS

From May 1999 to December 2001, SLNB was performed for 376 patients with T1-3 and N0-1 primary breast cancer using blue dye alone, radioisotope (RI) alone and combination of RI and blue dye. Two hundred sixty-eight patients underwent SLNB using blue dye alone. They were divided into 4 groups (Group A: n=50; peritumoral injection, Group B: n=83; the first half to receive subareolar injection, Group C: n=83; the second half to receive subareolar injection, and Group D: n=52; small incision according to an axillary skin landmark). One hundred eight patients underwent SLNB using RI. Tin colloid was used in 49 cases (Tin Colloid Group) and phytate in 59 cases (Phytate Group). Among them, 29 patients underwent injection of RI alone and 79 patients received a combination of RI and blue dye.

RESULTS

The identification rates of SLN using blue dye alone were 60%, 82%, 92% and 79% in Groups A, B, C and D, respectively. The identification rates of SLN in patients receiving RI alone and in those receiving combination of RI and blue dye were 40% and 89%, respectively, in Tin Colloid Group, and 92% and 94%, respectively, in Phytate Group.

CONCLUSION

When using blue dye alone, subareolar injection provided a better identification rate than peritumoral injection. The combination of peritumoral phytate and subareolar blue dye provided the best identification rate (94%) in all the groups. The combination of intraparenchymal phytate and subareolar blue dye was the most efficient technique for sentinel node biopsy in breast cancer patients.

Therapeutic relevance of breast cancer micrometastases in sentinel lymph nodes

BACKGROUND AND METHODS

This review examines the various methods of detecting occult breast cancer metastasis in the sentinel lymph node (SLN). The prognostic relevance of such micrometastases and isolated tumour cells, and their impact on stage migration and decision making with respect to axillary dissection and adjuvant systemic therapy, are discussed.

RESULTS

Examination of SLNs by serial section with haematoxylin and eosin and/or immuno histochemical staining significantly increases the detection rate of micrometastases, even in patients with very small (T1) tumours. However, the prognostic relevance of isolated tumour cells and small micrometastases is uncertain. Moreover, deciding which patients might benefit from axillary dissection is complicated by the fact that adjuvant radiotherapy and systemic chemotherapy alone may eradicate most micrometastases.

CONCLUSION

Ongoing randomized trials comparing the results of SLN biopsy alone with those of axillary dissection should answer the question of whether isolated tumour cells and small micrometastases are clinically relevant. This should also indicate which patients with SLN micrometastasis are likely to benefit from axillary dissection. In this sense, SLN biopsy must be considered still to be at an investigative stage; outwith clinical trials complete axillary dissection should be performed on all patients with SLN micrometastasis.

Sentinel lymph node biopsy in breast cancer: an overview of the Japanese experience

This paper reviews the Japanese literature regarding sentinel lymph node (SLN) biopsy in an attempt to provide an overview of existing controversies and to suggest a method for the identification of the SLN and the detection of micrometastases in the SLN to eliminate unnecessary axillary lymph node dissection (ALND). The combined dye- and gamma probe-guided method resulted in the accurate identification of the SLN in 96% of patients, compared with 80% when the dye-guided method alone was used. Although neither 99m-Tc sulfur colloid nor 99m-Tc colloidal albumin is commercially available in Japan, 99m-Tc stannous phytate and 99m-Tc rhenium colloid appear to be ideal tracers for identifying SLNs. Moreover, subdermal injection over the primary tumor or subareolar injection was found to enhance SLN identification, although these injection routes do not lead to detection of internal mammary SLNs. Furthermore, the accuracy of SLN diagnosis using frozen sections as well as imprint cytology improved with an increase in the number of sections, and could attain a sensitivity comparable to that obtained with routine histologic examination of permanent sections. As a result, several surgeons have begun to offer the option of forgoing ALND to patients with negative SLN. Although subsequent relapse in the axilla has not yet been reported, longer follow-up periods are needed to assess accurately the incidence of axillary failure in these negative SLN patients.

Sentinel lymph node biopsy and breast cancer

BACKGROUND AND METHOD

This paper reviews and discusses the feasibility and accuracy of sentinel lymph node (SLN) biopsy in breast cancer. A standardized method of identifying the SLN and detecting micrometastases is suggested, along with a strategy for the elimination of routine axillary lymph node dissection (ALND).

RESULTS

Although the SLN can be identified successfully by experienced practitioners using either the dye-guided or gamma probe-guided method, identification is facilitated when the two techniques are combined. To improve the likelihood of spotting metastases in the SLN, it is desirable to perform step sectioning combined with haematoxylin and eosin staining and immunohistochemistry of permanent and frozen sections. SLN biopsy is as accurate for T2 tumours as it is for T1 tumours. However, it is highly unlikely that all false-negative cases can be eliminated, even by detailed histological examination. Nevertheless, patients with T1 tumours with micrometastases in the SLN have shown no evidence of tumour in the non-sentinel nodes. In other words, ALND can be avoided in these patients, even if histological examination of the SLN fails to detect micrometastasis.

CONCLUSION

In practice, routine ALND can be avoided in patients with T1 tumours when the identified SLN proves to be histologically negative. However, investigation of long-term regional controls and of survival in a prospective randomized trial is necessary before SLN biopsy can replace routine ALND, particularly for patients with T2 tumours.

Sentinel lymph nodes study in 30 cases of melanoma

In 30 cases of melanoma, we attempted to detect sentinel lymph nodes using 1-2% patent blue dye and were able to detect them in 27 cases (90%): 19 cases out of 21 cases in the groin area (90%), 5 out of 5 cases in the axilla area (100%), and 3 out of 4 cases in the neck area (75%). The numbers of sentinel lymph nodes were one in 16 cases, two in 7 cases, three in 2 cases, and four in 2 cases. The cases with three and four nodes were all in the groin area. In 22 cases, tumor metastasis was negative in sentinel lymph nodes. Sentinel lymph nodes were detected in 36 out of 174 samples, and tumor metastasis was negative except in these sentinel lymph nodes (false negative 0%). In the groin area, sentinel lymph nodes were located around the femoral and great saphenous vein junction. In the axilla area, sentinel lymph nodes were located in the central, lateral and subscapular lymph nodes. In the head and neck area, sentinel lymph nodes were found in the submandibular and occipital lymph nodes. The positions of sentinel lymph nodes differed a little with tumor location. By accumulating cases, it should become possible to predict the positions of sentinel lymph nodes before operations. Sentinel lymph node biopsy is easy and requires only a small incision.

Clinical and pathologic factors predicting axillary lymph node involvement in breast cancer

The diagnosis of axillary disease remains a challenge in the management of breast cancer and is a subject of controversy. In 1998, the Japanese Breast Cancer Society conducted a study assessing axillary lymph node involvement in breast cancer. The study included (a) clinical assessment by pre-operative imaging modalities, (b) histologic assessment for peritumoral lymphatic invasion, (c) biologic assessment by gelatinolytic activity using film in situ zymography, and (d) sentinel lymph node (SLN) biopsy. Clinical assessments by CT, PET, and US as well as biologic assessment were limited in their ability to detect axillary lymph node disease, although these imaging techniques may be useful to exclude node-positive patients from the need for SLN biopsy. Histologic assessment for peritumoral lymphatic invasion was useful, particularly for detecting false-negative cases by SLN biopsy. Nevertheless, the utility of SLN biopsy in assessing axillary nodal status was confirmed. Axillary lymph node dissection (ALND) can be avoided in patients with a small tumor and a negative SLN. However, further studies will be required to investigate the value of SLN biopsy for predicting regional control and survival before it can replace routine ALND as the optimal staging procedure for operable breast cancer.

Sentinel lymph node biopsy in breast cancer using blue dye with or without isotope localization

BACKGROUND

The purpose of this study was to determine the feasibility of sentinel lymph node (SLN) biopsy using blue dye with or without isotope localization to predict the presence of axillary and internal mammary lymph node (IMN) metastases in patients with breast cancer. We also investigated whether multiple sectioning of the SLN could improve the accuracy of frozen section examination.

METHOD

One-hundred twenty-six patients underwent dye-guided or dye- and gamma probe-guided SLN biopsy followed by complete axillary lymph node dissection (ALND). No ALND was performed in the 14 patients with small tumors and a negative SLN. In addition, 69 patients underwent IMN biopsy.

RESULTS

The axillary SLN was identified in 123 of 140 (88%) patients. An accuracy rate of 90% was obtained by frozen section examination of the SLN, which increased to 100% in patients examined with a greater number of sections. Lymphatic flow to the IMN and/or a radioactive hot spot in the IMN was found in 9 of 102 (9%) patients, while a hot node was detected using a gamma probe in only 2 of these patients. No involvement of the IMNs was found histologically in these 9 patients. IMN involvement was found in 7 of 61 (11%) patients without lymphatic flow to the IMNs or a hot spot by lymphoscintigraphy or who did not undergo lymphoscintigraphy.

CONCLUSION

ALND can be avoided in patients with small breast cancers and a negative SLN. SLN biopsy guided by lymphatic mapping is unreliable for identifying metastases to IMNs.

Sentinel lymph node biopsy as an alternative to routine axillary lymph node dissection in breast cancer patients

Sentinel lymph node (SLN) biopsy is a useful way of assessing axillary nodal status and obviating axillary lymph node dissection (ALND) in patients with node-negative breast cancer. Because SLN technology is evolving rapidly, however, variation in technique is widespread, and no standardization has yet been accomplished. This review discusses the feasibility and accuracy of this procedure and suggests the optimal method for identifying the SLN and detecting micrometastases. Although the SLN can be successfully identified by either the dye-guided or gamma probe-guided method in experienced hands, identification is facilitated when the two techniques are used together. In the gamma probe-guided method, the use of a large-sized radiotracer (particle size, 200-1000 nm) may be preferred because only one or two SLNs are identified. To increase the chance of finding metastases in SLN, it is desirable to make step sections with hematoxylin and eosin staining on permanent and frozen sections. The addition of immunohistochemistry may improve the accuracy of SLN diagnosis. The intraoperative examination of imprint cytology may be useful in determining the status of the SLNs, but further studies are needed to establish whether it has additional value when combined with the frozen section. In practice, routine ALND can be avoided when there is documentation of extensive experience and a low false-negative rate with the technique in the hands of a particular surgeon and hospital team. Particularly, SLN biopsy is more successful and has a lower false-negative rate in patients with smaller tumors. However, investigation of long-term regional control and survival in a prospective randomized trial is necessary, before SLN biopsy can replace routine ALND as the preferred staging operation for women with breast cancer.

A multicenter validation study of sentinel lymph node biopsy by the Japanese Breast Cancer Society

Several pilot studies have indicated that SLN biopsy can be used to identify axillary lymph node metastases in patients with breast cancer. To confirm this finding, a multicenter study in a variety of practice settings was performed. A total of 674 patients with breast cancer at five institutions were enrolled. The techniques of SLN identification included the vital dye-guided and the vital dye- and gamma probe-guided methods. The SLN was removed, and complete axillary lymph node dissection (ALND) was performed. SLN and ALND specimens were examined separately. The SLN was successfully identified in 214 (94%) of 227 patients using the combined dye- and gamma probe-guided methods. The SLN was identified in 332 (74%) of 447 patients using vital dye-guided method alone. Patient age of at least 21 years, medially located primary tumor, and clinically positive nodes were correlated with failure to identify the SLN. The accuracy of SLN biopsy for the detection of metastatic disease was 96% (522 of 546), and the sensitivity was 90% (203 of 226). Accuracy of 100% was achieved in the patients with tumors less than 1.6 cm in diameter. All 23 false negative results occurred with larger primary tumors. SLN biopsy can accurately predict the presence or absence of axillary lymph node metastases, particularly in patients with small (< or = 1.5 cm) breast cancers.

Pilot study on sentinel node biopsy in breast cancer

BACKGROUND AND OBJECTIVES

Sentinel node biopsy (SNB) in breast cancer using indigo carmine was started in January 1998, and this method has proved feasible and reliable. From our initial experience, sentinel lymph nodes (SLNs) were identified in 65 of 88 cases of breast cancer (74%).

METHODS

Lymphatic mapping in breast cancer was assessed using radionuclide, technetium-99m human serum albumin or technetium-99m tin colloid. A pilot study on SNB with dye or a combined method was performed between August 1998 and January 1999.

RESULTS

SLNs were identified in 55 of 59 cases (93%). False-negative SLNs were found in 2 cases. The sensitivity and accuracy in all cases were 92% and 96%. SLNs in 52 cases were also diagnosed by immediate frozen sectioning. The sensitivity and accuracy were 89% and 96%.

CONCLUSIONS

SNB in the combined method was the best way to identify SLNs in breast cancer.

Dye- and gamma probe-guided sentinel lymph node biopsy in breast cancer patients: using patent blue dye and technetium-99m-labeled human serum albumin

BACKGROUND

Sentinel lymph node (SLN) biopsy is a promising method for the diagnosis of the axillary nodal status. We examined the availability of the SLN biopsy using two mapping procedures: the dye- and gamma probe-guided method, and preoperative lymphoscintigraphy by gamma camera imaging.

METHODS

We enrolled 48 patients with breast cancer. Technetium-99m-labeled human serum albumin was injected into the subdermal tissue above the primary tumor or biopsy cavity, and preoperative gamma camera imaging was performed. After induction of general anesthesia, patent blue dye was injected into the peritumoral area prior to the surgical procedure. A handheld gamma-detection probe was used to assist in SLN detection. Careful dissection was performed to identify blue-stained afferent lymphatic vessels and nodes. An SLN was defined as any blue and/or radioactive node, and was excised. After SLN biopsy, axillary lymph node dissection of level I, II, and III was completed, in order to confirm the diagnostic ability of the SLN biopsy.

RESULTS

Intraoperative SLN identification of axillary lesions was successful in 43 of 48 patients (90%). The dye- and gamma probe-guided method was successful in 25 patients (52%), the dye-guided method alone succeeded in 11 patients (23%), and the gamma probe-guided method alone succeeded in 7 patients (15%). Preoperative lymphoscintigraphy revealed axillary focal accumulations in 29 of 48 patients (60%). All patients who underwent successful preoperative SLN identification by lymphoscintigraphy had successful intraoperative SLN identification. A diagnostic accuracy of 95%, a sensitivity of 89%, and a specificity of 100% were achieved in the diagnosis of axillary metastasis. Internal mammary SLNs were identified in four patients intraoperatively, but we could not detect cancer metastasis in the internal mammary SLNs.

CONCLUSIONS

The dye-guided and gamma probe-guided methods were complementary. Preoperative lymphoscintigraphy was useful to predict intraoperative SLN identification. Further study is necessary to assess the role of SLN biopsy of the internal mammary lymph nodes.

Indications and technique of sentinel lymph node biopsy in breast cancer using 99m-technetium labeled tin colloids

BACKGROUND

The status of the sentinel lymph node (SLN) can reflect the status of other lymph nodes in breast cancer. The efficacy of dye injection and radiolabeled tin colloids for the accurate identification of the SLN was investigated. The indications for SLN biopsy for determining clinical nodal status were also investigated.

METHODS

A total of 108 patients with breast cancers less than 5 cm were enrolled. Ninety-six patients were clinically node negative and 12 were node positive. About 2 hours before surgery, 1 to 2.5 ml of 99m-technetium-labeled tin colloid was injected around the tumor. Just before the operation, dye was also injected into the tissue surrounding the tumor. Six clinically node negative patients were omitted from the dye-injection process. The SLN was identified as a lymph node with extremely high radioactivity using a gamma probe or a gamma counter. Complete axillary dissection was performed and the metastatic status investigated by hematoxylin and eosin staining.

RESULTS

In clinically node negative patients undergoing dye-injection, the SLN was identified in 89 of 90 patients (98.9%), and there was only one patient with lymph node metastasis outside the SLN. However, in clinically node positive patients undergoing dye-injection, the identification rate of the SLN was 66.7% (8 of 12 patients) and there was one patient with lymph node metastasis outside the SLN (12.5%). Without dye-injection, the SLN could be detected in 4 of 6 patients (66.7%).

CONCLUSIONS

Successful identification of the SLN with tin colloid requires concomitant dye-injection and candidates for SLN biopsy should be restricted to clinically node negative cases.

Staging efficacy of breast cancer with sentinel lymphadenectomy

Seventy-two patients underwent dye-guided or dye- and gamma probe-guided sentinel lymphadenectomy (SLND) followed by complete axillary lymph node dissection (ALND). The results of imprint cytology, frozen sections, and permanent sections of the sentinel lymph node (SLN) were compared to each other and to the histologic findings in the nonsentinel nodes. The SLN was identified in 62 (88%) of 72 patients. Evaluation of the SLN on the permanent sections yielded a diagnostic accuracy of 95%, a sensitivity of 89%, and a specificity of 100%, although the reliability of SLN diagnosis using frozen sections or imprint cytology is limited. Therefore, it may be concluded that SLND with multiple sectioning and histopathologic examination of the SLNs can predict the presence or absence of axillary-node metastases in patients with breast cancer. However, further studies will be needed to investigate the value of SLND in respect to the long-term regional control and any possible detriment or benefit to survival, before it can replace routine ALND as the preferred staging operation for operable breast cancer.