Rationale for superficial injection techniques in lymphatic mapping in breast cancer patients

Internal mammary node involvement in patients with axilla-negative early breast cancer: a narrative review

Early breast cancer staging involves radiological and pathological evaluation of the tumour and regional lymph nodes. The internal mammary nodes (IMN) are an important site of possible metastasis and influence disease stage and prognosis. However, the recommendation for routine IMN assessment remains unclear. Internal mammary sentinel lymph node biopsy (SLNB) is associated with increased morbidity and an unknown survival benefit. Furthermore, the IMN are traditionally thought to be involved only synchronous with, or following, axillary node (AXN) metastasis. The aim of this review is to determine the prevalence of IMN metastasis in patients with axilla-negative early breast cancer. A narrative review of studies assessing IMN metastasis was performed. The literature search was completed using the database Medline (Ovid). Twenty-two retrospective studies were identified. The studies included data from SLNB, US, MRI, PET/CT and opportunistic biopsy during free-flap reconstruction (FFR). The prevalence of isolated IMN metastasis ranged from 1.2% to 17.9%.

Efficacy of Periareolar Versus Peritumoral Injection of TC99-Labelled Sulphur Colloid and Methylene Blue Dye for Detection of Sentinel Lymph Node in Patients with Early Breast Cancer: a Comparative Study

Sentinel lymph node biopsy using dual methods of blue dye and radioactive isotope is what is practised as the standard of care at most of the centres. The combined use of radioactive colloid and blue dye injection is considered the gold standard for axillary sentinel lymph node biopsy in breast cancer with a 97% accuracy rate. The aim of this study is to determine the optimal injection site for methylene blue dye and Tc99-labelled sulphur colloid for sentinel lymph node biopsy in early breast cancer. In both periareolar and peritumoral groups of patients, overall rate of identifying sentinel lymph node (hot, blue and hot and blue nodes) with dual dye was comparable (100% and 96.36%) with p value = 0.475. Also in both groups of patients, overall rate of getting pathological positive sentinel lymph node on final histopathological report was comparable (52.73% and 45.28%) with p value = 0.561. Periareolar versus peritumoral injection of dual dye shows comparable success rates for axillary sentinel lymph node identification and can be considered rapid and reliable method. However, the periareolar route is technically simple and especially privileged in nonpalpable (T0) and upper outer quadrant lesions mainly for the prevention of the shine through phenomenon.

Buffering the Suffering of Breast Lymphoscintigraphy

Breast lymphoscintigraphy with ^99mTc-sulfur colloid is frequently performed before breast-conserving surgery to delineate drainage to a sentinel node. Tracer injection for lymphoscintigraphy can be painful. Our aims were to determine whether administering a solution of buffered lidocaine immediately before lymphoscintigraphy injection could both reduce the patients' pain and increase nuclear medicine technologists' satisfaction with performing the procedure. Methods: A pain scale survey was obtained from patients undergoing breast lymphoscintigraphy with or without buffered lidocaine. Our nuclear medicine technologists were also surveyed for their satisfaction with the procedure, both with and without the addition of buffered lidocaine. Results: The patients' reported pain decreased by 86% with the addition of buffered lidocaine. Technologist satisfaction with performing the procedure increased by 36%. Conclusion: Lidocaine buffered with sodium bicarbonate injected before lymphoscintigraphy significantly reduces pain experienced by the patient and improves nuclear medicine technologist satisfaction in performing the procedure.

Hybrid surgical guidance based on the integration of radionuclear and optical technologies

With the evolution of imaging technologies and tracers, the applications for nuclear molecular imaging are growing rapidly. For example, nuclear medicine is increasingly being used to guide surgical resections in complex anatomical locations. Here, a future workflow is envisioned that uses a combination of pre-operative diagnostics, navigation and intraoperative guidance. Radioguidance can provide means for pre-operative and intraoperative identification of "hot" lesions, forming the basis of a virtual data set that can be used for navigation. Luminescence guidance has shown great potential in the intraoperative setting by providing optical feedback, in some cases even in real time. Both of these techniques have distinct drawbacks, which include inaccuracy in areas that contain a background signal (radioactivity) or a limited degree of signal penetration (luminescence). We, and others, have reasoned that hybrid/multimodal approaches that integrate the use of these complementary modalities may help overcome their individual weaknesses. Ultimately, this will lead to advancement of the field of interventional molecular imaging/image-guided surgery. In this review, an overview of clinically applied hybrid surgical guidance technologies is given, whereby the focus is placed on tracers and hardware.

Ultrasound-guided sentinel node procedure for nonpalpable breast carcinoma

PURPOSE

Peritumoral and periareolar tracer injection techniques lead to different lymphatic drainage in sentinel lymph node biopsy procedures. In a prospective study, the visualization and identification rates of the ultrasound (US)-guided tracer injection technique for palpable and nonpalpable breast tumors were evaluated.

METHODS

In 1262 consecutive patients with cT₁₋₂N0 breast cancer, sentinel lymph node biopsy was performed following peritumoral tracer injection. In the case of nonpalpable breast lesions, Tc-99m nanocolloid injections were given using a 7.5 MHz US probe. In the case of ultrasonographically nonvisible microcalcifications, the US-guided injection technique was wire guided.

RESULTS

In 331 patients with nonpalpable breast lesions (26.2%), the lymphoscintigraphic visualization and surgical retrieval rates of axillary sentinel lymph nodes (SLNs) were 98.5 and 99.4%, respectively. For internal mammary (IM) SLNs, these rates were 21.1 and 17.8%, respectively. These rates were similar in patients with palpable and nonpalpable tumors. Axillary metastases were detected in 38.7% of the patients with palpable tumors versus 16.5% of those with nonpalpable tumors (P<0.001), whereas IM metastases were found in 4.8 and 3.0% of patients, respectively (P=0.165).

CONCLUSION

In nonpalpable breast lesions, the US-guided injection technique is an accurate technique for SLN identification and retrieval. The substantial rates of IM metastases in both palpable and nonpalpable lesions favor a peritumoral tracer injection technique.

Methylene blue dye-related changes in the breast after sentinel lymph node localization

OBJECTIVES

The purpose of this study was to investigate the frequency and appearance of changes in the breast on sonography in patients after breast cancer surgery including sentinel lymph node localization using methylene blue dye.

METHODS

Three hundred thirty-seven consecutive patients who underwent breast-conserving surgery in 2006 underwent breast sonography during 2 years after surgery. Sentinel lymph node localization using methylene blue dye was selectively performed. We retrospectively analyzed the unexplained focal lesions not at the lumpectomy site on sonography and investigated whether these findings were associated with sentinel lymph node localization.

RESULTS

Unexplained focal lesions were identified in 36 (14.1%) of 256 patients who had undergone sentinel lymph node localization. The lesions were in the periareolar region (n = 26; outer in 16, upper in 6, inner in 2, and lower in 2) or the retroareolar region (n = 10). The lesion appeared with a fat necrosis-like pattern in the subcutaneous fat layer in 24 (66.7%) or as an irregular mass in the glandular layer in 12 (33.3%). The unexplained focal lesions were pathologically proven benign (n = 10) or were improved or stable during 2 years of imaging follow-up after surgery (n = 26). The unexplained focal lesions in 2 (2.5%) of 81 patients without sentinel lymph node localization were in the nonareolar region, and 1 of these was a recurrence.

CONCLUSIONS

After sentinel lymph node localization using methylene blue dye, breast sonography can show unexplained focal lesions in the periareolar and retroareolar regions. Although most of the changes suggest fat necrosis, an irregular parenchymal mass can develop and mimic a recurrence.

Sentinel lymph node biopsy in early breast cancer surgery--working with the risks of vital blue dye to reap the benefits

AIMS

Sentinel lymph node biopsy (SLNB) is an important method of staging early breast cancer because of the inherent benefits it confers on patients in terms of arm function and quality of life. Its success depends on a high level of accuracy in detecting the sentinel node. This is achieved by a dual mapping technique that employs a radio-labelled nanocolloid and a vital blue dye. The vital dyes however carry the risk of anaphylaxis, and as more surgeons employ SLNB in their daily practice, a proportionate rise in the number of anaphylactic reactions can be expected. A comprehensive review of risks and benefits associated with using vital blues dyes has not been published and therefore a retrospective review was undertaken of the different levels of anaphylaxis associated with vital dyes as well as their benefits in SLNB.

METHODS

An OVID MEDLINE search was performed of the English published literature using appropriate search terms to find published trial data and case series that focused on adverse reactions to vital blue dyes.

RESULTS

The risk of severe anaphylaxis (grade 3) can be as low as 0.06%, and up to 0.4% for patients undergoing SLNB when data is analysed from large trials. Furthermore, adverse reactions associated with blue dyes are reversible with appropriate management.

CONCLUSIONS

Surgeons should continue to use vital dyes to ensure that SLNB remains a highly sensitive procedure.

Current status of sentinel lymph-node biopsy in patients with breast cancer

Axillary node status is the most important prognostic indicator for patients with invasive breast cancer. Sentinel lymph-node biopsy (SLNB) is widely accepted and the preferred procedure for identifying lymph-node metastasis. SLNB allows focused excision and pathological examination of the most likely axillary lymph nodes to receive tumor metastases while avoiding morbidities associated with complete axillary nodal dissection. Since its introduction in the early 1990s, the process of SLNB has undergone continual modification and refinement; however, the procedure varies between institutions and controversies remain. In this review, we examine the technical issues that influence the success of lymph node mapping, discuss the controversies, and summarize the indications and contraindications for axillary node mapping and biopsy in clinical practice.

Axillary lymph node drainage pathways from intradermal and intraparenchymal breast planes

BACKGROUND

To compare functional anatomy of breast peri-areolar and peri-tumoral lymphatic drainage basins.

METHODS

Fifteen breast cancer patients received simultaneous peri-areolar (intradermal) and peri-tumoral (intraparenchymal) injections of human polyclonal immunoglobulin (HIG) labeled with (99m)Tc and (111)In 2 to 4 h before axillary lymph node clearance surgery. Resected nodes (range 5-20; median 16) were individually counted for (99m)Tc and (111)In in a well-counter and ranked according to activity content (echelon). Activity in distal nodes was negligible so extraction efficiency (E) of HIG in the first echelon node was calculated as counts divided by total counts in the chain.

RESULTS

Five- to 10-fold more activity was recovered after intradermal injection. The injection planes identified the same first echelon node in 10 patients (group 1) but different in five (group 2). In group 1, intradermal E correlated with intra-parenchymal E (r = 0.82; P < 0.01). E of intradermal first echelon nodes in group 2 was 51 (SD 13)%, similar to intradermal E in group 1 (58 [23]%). E of intraparenchymal first echelon nodes in group 2, however, was 28 (6)%, lower than intraparenchymal E in group 1 (54 [20]%; P < 0.02).

CONCLUSIONS

Lymph nodes extract approximately 50% of HIG. Extracted HIG does not cascade to distal nodes, validating HIG for sentinel node lymphoscintigraphy. HIG injected intradermally at the areola drains via a single route to the axilla. In two-thirds of patients, peri-tumoral HIG follows a similar route, but in one-third of patients drainage from the parenchymal plane is more complex, with more than one route to the axilla.

The sentinel node in breast cancer

Biopsy of the sentinel lymph node now forms part of routine management in many centres dealing with early stage breast cancer. This article seeks to discuss developments over the past number of years and to summarise current practice.

Safety and technical success of methylene blue dye for lymphatic mapping in breast cancer

BACKGROUND

We aimed to evaluate the safety and efficacy of methylene blue dye (MBD) for sentinel lymph node (SLN) mapping in breast cancer.

METHODS

A total of 398 patients undergoing 401 SLN biopsy procedures with MBD were retrospectively reviewed and divided into 3 groups based on dye concentration and location of dye injection. Technical success and complication rates were compared.

RESULTS

Overall technical success of SLN biopsy was 99.7%. Technical success of SLN mapping with MBD was lowest in the group receiving full strength dye in a peritumoral location (74%) and highest in the group that received very dilute MBD (1.25 mg/mL) in the subareolar location (92%, P = .004). The complication rate was highest in the first group (21%) and lowest in the latter (2%, P = .0003).

CONCLUSIONS

Dilute MBD (1.25 mg/mL) successfully maps SLNs with very few complications.

Subpleural injection of tracer improves detection of mediastinal sentinel lymph nodes in non-small cell lung cancer

BACKGROUND

The advantages and disadvantages of various tracer injection protocols for sentinel lymph node (SLN) mapping have been extensively discussed in relation to breast and gastric cancer. But no such discussion has taken place in relation to SLN mapping in non-small cell lung cancer. We therefore studied the effect of two tracer injection protocols on SLN mapping in patients with non-small cell lung cancer; of particular interest was the relationship between subpleural tracer injection and identification of mediastinal SLNs.

METHODS

A quadrant injection group (n=49) received 1.6 ml of ferucarbotran by peritumoral quadrant injection after thoracotomy. In the subpleural injection group, the same amount of ferucarbotran was injected into the peritumoral quadrants plus the subpleural region (n=27). SLNs were then detected intraoperatively by measuring the magnetic force within lymph nodes using a hand-held magnetometer. After completing the SLN mapping, lobectomy and hilar and mediastinal lymph node dissection was performed.

RESULTS

The incidence of mediastinal SLNs was significantly higher in the subpleural injection group (45.4%) than in the quadrant injection group (14.6%) (p=0.007). Moreover, nominal logistic regression analysis revealed subpleural injection to be a significant independent factor contributing to detection of mediastinal SLNs (p=0.024, odds ratio 5.26). In the quadrant injection group, mediastinal lymph node metastasis was detected in two patients thought to have nonmetastatic parenchymal SLNs. By contrast, there were no false-negative cases in the subpleural injection group.

CONCLUSION

Subpleural tracer injection significantly improves detection of mediastinal SLNs in non-small cell lung cancer.

Technical outcomes of sentinel-lymph-node resection and conventional axillary-lymph-node dissection in patients with clinically node-negative breast cancer: results from the NSABP B-32 randomised phase III trial

BACKGROUND

The goals of axillary-lymph-node dissection (ALND) are to maximise survival, provide regional control, and stage the patient. However, this technique has substantial side-effects. The purpose of the B-32 trial is to establish whether sentinel-lymph-node (SLN) resection can achieve the same therapeutic goals as conventional ALND but with decreased side-effects. The aim of this paper is to report the technical success and accuracy of SLN resection plus ALND versus SLN resection alone.

METHODS

5611 women with invasive breast cancer were randomly assigned to receive either SLN resection followed by immediate conventional ALND (n=2807; group 1) or SLN resection without ALND if SLNs were negative on intraoperative cytology and histological examination (n=2804; group 2) in the B-32 trial. Patients in group 2 underwent ALND if no SLNs were identified or if one or more SLNs were positive on intraoperative cytology or subsequent histological examination. Primary endpoints, including survival, regional control, and morbidity, will be reported later. Secondary endpoints are accuracy and technical success and are reported here. This trial is registered with the Clinical Trial registry, number NCT00003830.

FINDINGS

Data for technical success were available for 5536 of 5611 patients; 75 declined protocol treatment, had no SLNs removed, or had no SLN resection done. SLNs were successfully removed in 97.2% of patients (5379 of 5536) in both groups combined. Identification of a preincision hot spot was associated with greater SLN removal (98.9% [5072 of 5128]). Only 1.4% (189 of 13171) of SLN specimens were outside of axillary levels I and II. 65.1% (8571 of 13 171) of SLN specimens were both radioactive and blue; a small percentage was identified by palpation only (3.9% [515 of 13 171]). The overall accuracy of SLN resection in patients in group 1 was 97.1% (2544 of 2619; 95% CI 96.4-97.7), with a false-negative rate of 9.8% (75 of 766; 95% CI 7.8-12.2). Differences in tumour location, type of biopsy, and number of SLNs removed significantly affected the false-negative rate. Allergic reactions related to blue dye occurred in 0.7% (37 of 5588) of patients with data on toxic effects.

INTERPRETATION

The findings reported here indicate excellent balance in clinical patient characteristics between the two randomised groups and that the success of SLN resection was high. These findings are important because the B-32 trial is the only trial of sufficient size to provide definitive information related to the primary outcome measures of survival and regional control. Removal of more than one SLN and avoidance of excisional biopsy are important variables in reducing the false-negative rate.

Prospective Multicentric Randomized Study Comparing Periareolar and Peritumoral Injection of Radiotracer and Blue Dye for the Detection of Sentinel Lymph Node in Breast Sparing Procedures: FRANSENODE Trial

Purpose

To determine the optimal injection path for blue dye and radiocolloid for sentinel lymph node (SLN) biopsy in early breast cancer.

Patients and Methods

A prospective randomized multicentric study was initiated to compare the peritumoral (PT) injection site to the periareolar (PA) site in 449 patients.

Results

The detection rate of axillary SLN by lymphoscintigraphy was significantly higher (P = .03) in the PA group (85.2%) than in the PT group (73.2%). Intraoperative detection rate by blue dye and/or gamma probe was similar (99.11%) in both groups. The rate of SLN detection was somewhat higher in the PA group than in the PT group: 95.6% versus 93.8% with blue dye (P = .24) and 98.2% versus 96.0% by probe (P = .16), respectively. The number of SLNs detected by lymphoscintigraphy and by probe was significantly higher in the PA group than in the PT group, 1.5 versus 1.2 (P = .001) and 1.9 versus 1.7 (P = .02). The blue and hot concordance was 95.6% in the PA group and 91.5% in the PT group (P = .08). The mean ex vivo count of the SLN was significantly higher in the PA group than in the PT group (P < .0001).

Conclusion

This study strongly validates the PA injection technique given the high detection rate (99.1%) of SLN and the high concordance (95.6%) between blue dye and the radiotracer, as well as higher significant ex and in vivo counts, improving SLN probe detection.

Aspectos técnicos de interés en la localización de drenajes linfáticos en la biopsia del ganglio centinela del cáncer de mama

OBJECTIVES

The sentinel node is defined as the node with the highest probability of being involved in the case of lymphatic spread from a tumor. Accurate identification and biopsy of this node can avoid unnecessary lymphadenectomies. The aim of this study was to determine if there are differences in the number of isolated sentinel lymph nodes in breast cancer according to whether a mixed technique (vital dye plus isotopic tracer) or radiotracer alone is used and if there are differences in the detection of more than one lymphatic basin and in the number of lymphatic nodes depending on the site of tracer injection.

PATIENTS AND METHOD

A total of 173 sentinel lymph node biopsies in 173 women with breast cancer were studied taking into account the technique (mixed [n = 109] or radiotracer alone [n = 64]) and the location of tracer injection (periareolar [n = 81], intra and/or peritumoral [n = 92]). The number of lymphatic basins and the number of sentinel nodes were compared among the distinct groups resulting from the combination of the 2 parameters.

RESULTS

Simultaneous drainage to both the axilla and internal mammary chain was more frequent with the intra-periareolar technique. The number of identified nodes was significantly higher when mixed techniques were compared, and was higher with periareolar injection than with the intra-peritumoral route.

CONCLUSIONS

In breast cancer sentinel lymph node biopsy, the number of identified nodes is not influenced by the use of a mixed technique or radiotracer alone. However, the number of identified nodes is higher with the periareolar route than with the intra-peritumoral route. Intra-peritumoral injection of the tracer shows a higher frequency of internal mammary chain drainage than periareolar injection, although this difference was not statistically significant.

Optimal number of sentinel nodes after intradermal injection isotope and blue dye

BACKGROUND

Sentinel node (SN) biopsy for breast cancer is becoming more common owing to its lower morbidity when compared with full axillary dissection. However, the optimal method of finding and the number of SN to be dissected are still subject to conjecture. The aim of this study was to determine the optimal number of SN required to accurately stage an axilla after the i.d. injection of isotope and blue dye.

METHOD

Prospective data from all patients undergoing SN biopsy from April 2000 to September 2004 were analysed. For positive SN, the order in which they became positive was then tabulated.

RESULTS

During the 4 years, 113 patients who fulfilled the selection criteria had undergone SN biopsy with 216 SN harvested. Of these, 33 patients had positive SN results. If only the first SN was analysed, 87.9% of those positive biopsies would have been discovered. Two SN raised the predictive value to 97.0%.

CONCLUSION

Two SN would seem to be the optimal number to harvest after i.d. injection of both isotope and blue dye.

Clinical and Therapeutic Importance of Sentinel Node Biopsy of the Internal Mammary Chain in Patients with Breast Cancer: A Single-Center Study with Long-Term Follow-Up

BACKGROUND

We evaluated the incidence of sentinel lymph nodes (SLNs) in the internal mammary chain, calculated the lymphoscintigraphy and surgical detection rates, and evaluated the clinical effect on staging and the therapeutic approach in patients with breast cancer.

METHODS

The study involved 741 women diagnosed with breast cancer eligible for the SLN technique. Lymphoscintigraphy was performed on the day before the operation by peritumoral injection of (99m)Tc-labeled nanocolloid. During the operation, a gamma probe was used to detect the SLN, which was then removed.

RESULTS

A total of 719 SLNs were found in the axillary chain and 72 in the internal mammary chain. Preoperative lymphoscintigraphy showed 107 hot spots in the internal mammary chain, but only 72 SLNs in 65 patients were identified by the gamma probe and then removed with no complications. Of these 65 patients, 10 had a positive internal mammary chain SLN on final pathologic examination, whereas 55 patients had >or=1 negative SLNs on final pathologic analysis. Thirty-five (53%) of 65 patients had also an axillary SLN, but only 5 patients (8%) had a positive SLN on pathologic analysis.

CONCLUSIONS

Evaluation of the SLNs in the internal mammary chain may provide more accurate staging in breast cancer patients. If an internal mammary sampling is not performed, patients may be understaged. This technique may allow better selection of those patients who will be submitted to adjuvant locoregional radiotherapy.

Experience with intradermal injection and intradermal-plus-deep injection in the radioguided sentinel node biopsy of early breast cancer patients

AIMS

Methods of administering (99m)Tc-phytate during sentinel node biopsy of early breast cancer patients were compared to improve the sensitivity of the technique.

METHODS

Two injection methods, intradermal vs. intradermal-plus-deep injection, were compared in 648 early breast cancer patients. Intradermal injection was done in 323 consecutive patients (325 breasts), and intradermal-plus-deep injection was done in 325 consecutive patients (329 breasts). The following items were compared: (1) The number of axillary nodes detected scintigraphically and removed surgically, and the breast number of micrometastasis to axillary nodes; (2) The number of internal mammary nodes detected scintigraphically and removed surgically; and (3) The sensitivity of axillary SNB.

RESULTS

The number of axillary nodes scintigraphically detected was 1.63+/-0.80 (mean+/-SD) in patients given intradermal injection, and was 1.82+/-0.94 in patients given intradermal-plus-deep injection. The number of axillary nodes surgically removed was 1.78+/-0.93 in patients given intradermal injection, and was 1.95+/-0.99 in patients given intradermal-plus-deep injection. The visualization of internal mammary nodes was superior with intradermal-plus-deep injection (5/325 for intradermal, and 51/329 for intradermal-plus-deep). The putative sensitivity was 71/72 (98.6%) for the intradermal-plus-deep method and 56/62 (90.3%) for the intradermal method. The frequency of detection of micrometastasis was 24 in 71 true positive (38.8%) for the intradermal-plus-deep method and 13 in 56 true positive (23.2%) for the intradermal method.

CONCLUSIONS

The SNB procedure with the intradermal-plus-deep injection method detected more axillary and internal mammary nodes, more (not statistically significant) micrometastasis and improved the putative sensitivity more than the SNB procedure with the intradermal injection method.

The sentinel node in breast cancer: an update

There has been rapid acceptance of sentinel lymph node biopsy into the management of breast cancer over the past 10 years. This article seeks to highlight the controversies and to summarise its current status.

Clinical relevance of sentinel lymph nodes in the internal mammary chain in breast cancer patients

PURPOSE

Despite the widespread use of sentinel lymph node (SLN) biopsy in breast cancer patients, some controversy exists about the correct management of extra-axillary nodes, especially those located in the internal mammary chain. The aim of this study was to evaluate the incidence of SLNs in this region, calculate the lymphoscintigraphic and surgical detection rates and evaluate the clinical impact on staging and therapeutic decisions.

METHODS

The study involved 383 consecutive women diagnosed with early breast cancer with T1 or T2 tumours. Eight patients had a bilateral tumour, which brought the total to 391 lesions. Lymphoscintigraphy was performed on the day before surgery by injection of (99m)Tc-labelled nanocolloid. The injection site was subdermal (68 patients), peritumoural (107 patients) or intratumoural (216 patients). During surgery a gamma probe was used to guide the surgeon and the SLNs were removed. SLNs were analysed by a conventional pathological study and processed for H&E examination and immunohistochemistry.

RESULTS

Lymphoscintigraphy detected at least one SLN in 369 out of the 391 procedures (94.4%). SLNs were found in the axillary chain in 367 cases and in the internal mammary chain in 55. In two of these 55 cases (3.6%), the SLN was the only one detected. There was no drainage to the internal mammary chain in any case of subdermal injection but such drainage was found in 15.9% of cases with peritumoural injection and 17.6% of those with intratumoural injection. Compared with tumours located in the outer quadrants, a higher percentage of tumours located in the inner quadrants showed drainage to the internal mammary chain (p<0.001). A total of 42 SLNs in the internal mammary chain could be removed in 32 patients without appreciable morbidity. In 20 cases both axillary and internal mammary SLNs were negative, in four both were positive, and in five axillary SLNs were positive and internal mammary SLNs were negative. More interestingly, in the remaining patient with both axillary and internal mammary SLNs, the axillary SLN was negative while malignant cells were found in the internal mammary region. In the evaluation of the clinical impact of internal mammary SLN biopsy, we found that staging was modified from pN1a to pN1c in four patients and, more importantly, from pN0 to pN0(i+) in one patient. The change in stage led to a modification of the postoperative treatment plan with respect to radiotherapy and systemic therapy.

CONCLUSION

Evaluation of the SLNs in the internal mammary chain provides more accurate staging of breast cancer patients. If internal mammary sampling is not performed, patients can be understaged. This technique can offer a better indication of those patients who will benefit from selective treatment options like radiotherapy to this region or systemic therapy.

Optical molecular imaging of lymph nodes using a targeted vascular contrast agent

We develop a highly specific antibody-dye conjugate for optical imaging of peripheral lymph nodes. The contrast agent consists of the monoclonal antibody recognizing endothelial ligands for the lymphocyte homing receptor L-selectin, MECA-79, and a near-infrared (near-IR) fluorescent indotricarbocyanine dye. The targeting and biodistribution behavior of MECA-79 is studied after radio-iodination and intravenous injection into mice demonstrating specific uptake in lymph nodes and accumulation in high endothelial venules (HEV). After conjugation of MECA-79 with indotricarbocyanine dye, the fluorescence imaging properties of the MECA-79 dye conjugate are examined by intravenous injection in nude mice and laser-induced fluorescence whole-body imaging in vivo. The MECA-79 antibody-dye conjugate accumulates in peripheral lymph nodes, whereas an isotype antibody-dye conjugate does not. Specific lymph node near-IR fluorescent signals become detectable within minutes after injection, and stable imaging persists for more than 24 h. The results demonstrate that vascular targeting of endothelial expression of glyocproteins is feasible to visualize the accumulation of near-IR fluorescent MECA-79 in lymph nodes, making this technology potentially useful to characterize processes of inflammation.

Update on detection of sentinel lymph nodes in patients with breast cancer

Sentinel lymph node biopsy is now the practice of choice for the management of many patients with breast cancer. This was not true in the early 1990s, when the first such procedures were performed and protocols for such were refined often. This was also not true in the first years of the 21st century, when a decade of collective experience and information acquired from numerous clinical investigations dictated additional subtle and not-so-subtle refinements of the procedures. However, it is true today; reports of the latest round of clinical investigations indicate that there are several breast cancer sentinel node procedures that result in successful identification of potential sentinel nodes in nearly all patients who are eligible for such procedures. A significant component of many of these successful sentinel node procedures is a detection and localization protocol that involves radiotracer methodologies, including radiopharmaceutical administration, preoperative nuclear medicine imaging, and intraoperative gamma counting. The present state and roles of nuclear medicine protocols used in breast cancer sentinel lymph node biopsy procedures is reviewed with emphasis on discussion of recent results, unresolved issues, and future considerations. Included are brief reviews of present radiotracer and blue-dye techniques for node localization, including remarks about injection strategies, counting probe technology, and radiation safety. Included also are discussions of on-going investigations of the implications of the presence of micrometastases; of the management value of detection, localization, and excision of extra-axillary nodes such as internal mammary nodes; and of the broad range of recurrence rates presently being reported. Remarks on the present and possible near- and long-term roles for nuclear medicine in the staging of breast cancer patients including comments on positron emission tomography and intraoperative imaging conclude the article.