Intraoperative identification of sentinel lymph node in patients with malignant melanoma

Biomedical Applications of Quantum Dots: Overview, Challenges, and Clinical Potential

Despite the massive advancements in the nanomedicines and their associated research, their translation into clinically-applicable products is still below promises. The latter fact necessitates an in-depth evaluation of the current nanomedicines from a clinical perspective to cope with the challenges hampering their clinical potential. Quantum dots (QDs) are semiconductors-based nanomaterials with numerous biomedical applications such as drug delivery, live imaging, and medical diagnosis, in addition to other applications beyond medicine such as in solar cells. Nevertheless, the power of QDs is still underestimated in clinics. In the current article, we review the status of QDs in literature, their preparation, characterization, and biomedical applications. In addition, the market status and the ongoing clinical trials recruiting QDs are highlighted, with a special focus on the challenges limiting the clinical translation of QDs. Moreover, QDs are technically compared to other commercially-available substitutes. Eventually, we inspire the technical aspects that should be considered to improve the clinical fate of QDs.

Mapping the Sentinel Lymph Node in Malignant Melanoma by Blue Dye, Lymphoscintigraphy and Intraoperative Gamma Probe

Eighty-eight consecutive patients (48 men and 40 women; mean age, 58.9 years; range, 16–84 years) with clinically localized cutaneous melanoma involving the trunk, extremities or head and neck underwent lymphatic mapping at our institution. The primary melanoma had a mean thickness of 2.74 mm (range, 0.95 to 9 mm). Patients were divided into two groups: group A (39 patients) underwent only vital blue dye (VBD) mapping, while group B (49 patients) underwent lymphatic mapping with VBD and radio-guided surgery (RGS) combined. In all patients 1-1.5 mL of VBD was injected subdermally around the biopsy scar 10–20 min before surgery. In group B 37 MBq in 150 μL of 99mTc-HSA nanocolloid was additionally injected intradermally 18 h before surgery (3–6 aliquots injected perilesionally). In all lymphatic basins where drainage was noted the sentinel lymph nodes (SNs) were identified and marked with a cutaneous marker. Final identification of the SN was then performed externally by a hand-held gamma probe. After the induction of anesthesia 0.5–1-0 mL of patent blue V dye was injected intradermally with a 25-gauge needle around the site of the primary melanoma. SNs were examined by routine hematoxylin and eosin (H&E) staining and immunohistochemistry. Patients with histologically positive SN(s) underwent standard lymph node dissection (SLND) in the involved lymph node basin.

The SN was identified in 37/39 patients (94.9%) of group A and in 48/49 patients (98.0%) of group B. Blue dye mapping failed to identify the SN in 5 of the 88 patients (5.8%), while the radioisotope method failed in only 1 of 49 patients (2.0%). Similar results were obtained with the combined use of the two probes. The average number of SNs harvested was 1.9 per basin sampled, which does not differ significantly from the numbers reported by other authors114. The SN was histologically positive in 18 patients (20.5%). None of the 12 patients with a Breslow thickness less than 1.5 mm had positive SNs, whereas 18 of the 77 patients (23.4%) with a Breslow index exceeding 1.5 mm showed metastatic SNs with H&E or immunohistochemistry. The latter all underwent SLND of the affected basin. In 10 patients (55.6%) the SN was the only site of tumor invasion; eight patients (44.4%) with positive SNs had one or more metastatic lymph nodes in the draining basin.

Metastases of malignant neoplasms: Historical, biological, & clinical considerations

The metastasis of neoplastic cells from their site of origin to distant anatomic locations continues to be the principal cause of death from malignant tumors, and that fact has been recognized by physicians for over a century. After the work done by Halsted in the treatment of breast cancer in the 1880s, accepted surgical canon held that metastasis occurred in a linear fashion, with centrifugal "growth in continuity" from the primary neoplasm that first involved regional lymph nodes. Those structures were considered to then be the sources of more distant, visceral metastases. With that premise in mind, radical and "ultra-radical" surgical procedures were devised to remove as many lymph nodes as possible in the treatment of carcinomas and melanomas. However, such interventions were ineffective in altering tumor-related mortality. This review considers the details of the historical material just mentioned. It also reviews currently-held concepts on biological mechanisms of metastasis, the "sentinel" lymph node biopsy technique, and the important topic of metastatic tumor "dormancy" as the cause of surgical treatment failure. Finally, predictive models of tumor behavior are discussed, which are based on gene signatures. These will likely be the key to identifying malignant lesions of low surgical stage that ultimately prove fatal through later manifestation of metastasis.

Evidence-Based Principles in Pathology: Existing Problem Areas and the Development of “Quality” Practice Patterns

Context.—Contrary to the intuitive impressions of many pathologists, several areas exist in laboratory medicine where evidence-based medicine (EBM) principles are not applied. These include aspects of both anatomic and clinical pathology. Some non-EBM practices are perpetuated by clinical “consumers” of laboratory services because of inadequate education, habit, or overreliance on empirical factors. Other faulty procedures are driven by pathologists themselves.

Objectives.—To consider (1) several selected problem areas representing non-EBM practices in laboratory medicine; such examples include ideas and techniques that concern metastatic malignancies, “targeted” oncologic therapy, general laboratory testing and data utilization, evaluation of selected coagulation defects, administration of blood products, and analysis of hepatic iron-overload syndromes; and (2) EBM principles as methods for remediation of deficiencies in hospital pathology, and implements for the construction of “quality” practices in our specialty.

Data Sources.—Current English literature relating to evidence-based principles in pathology and laboratory medicine, as well as the authors' experience.

Conclusions.—Evidence-based medicine holds the promise of optimizing laboratory services to produce “quality” practices in pathology. It will also be a key to restraining the overall cost of health care.

Metastasis of squamous cell carcinoma of the oral tongue

Squamous cell carcinoma of the oral tongue (SCCOT) is one of the most prevalent tumors of the head and neck region. Despite advances in treatment, the survival of patients with SCCOT has not significantly improved over the past several decades. Most frequently, treatment failure takes the form of local and regional recurrences, but as disease control in these areas improves, SCCOT treatment failures are occurring more often as distant metastasis. The presence of cervical lymph node metastasis is the most reliable adverse prognostic factor in patients with SCCOT, and extracapsular spread (ECS) of cervical lymph nodes metastasis is a particularly reliable predictor of regional and distant recurrence and death from disease. Decisions regarding the elective and therapeutic management of cervical lymph node metastases are made mainly on clinical grounds as we cannot always predict cervical lymph node metastasis from the size and extent of invasion of the primary tumors. Therefore, the treatment of these metastases in the management of SCCOT remains controversial. The promise of basing treatment decisions on biomarkers has yet to be fully realized because of our poor understanding of the mechanisms of regional and distant metastases of SCCOT. Here we summarize the current status of investigations of SCCOT metastases and the potential of these studies to have a positive impact on the clinical management of SCCOT in the future.

Clinical Study of Neck Dissection for Lymph Node Metastasis in Patients with Malignant Skin Tumors of the Forehead and Face

We reviewed the records of 10 patients with malignant skin tumors of the forehead and face who underwent neck lymph node dissection at Kurume University Hospital between 2000 and 2004. Two patients underwent selective neck dissection (SND), 5 patients underwent SND and superficial parotidectomy (SP) and 3 patients underwent modified radical neck dissection and SP. Lymph node metastasis to the upper jugular group was found in 3 patients, and metastasis to lymph nodes of the parotid region was found in 3 patients. In a patient with malignant melanoma of the forehead, the patent blue dye was injected intradermally around the tumor and blue-stained lymph nodes were identified in the upper jugular group and parotid region. From these results, we consider that the sentinel lymph nodes of frontal and facial malignant tumors are located in the upper jugular group and parotid region. Thus, in malignant skin tumor patients, SND and SP might be mandatory.

[Feasibility and technical problems of sentinel node analysis in melanoma]

BACKGROUND

Development of the sentinel lymph node (SLN) biopsy the last 10 years has changed surgical approach of solid tumor treatment and particularly of melanoma. The aim of our study was to analyze in our hospital, the feasibility of the SLN biopsy technique in order to define a better prognostic classification of melanomas.

PATIENTS AND METHODS

Between July 1999 and October 2003, 97 patients were included in this study in our center. Criteria for inclusion were cutaneo-mucosal melanoma of Breslow >or=1,5 mm, and/or Clarck >or=IV, and/or ulceration, and/or signs of regression, before any surgical margins.

RESULTS

Lymphoscintigraphy (LS) identified at least 1 SLN in 94 cases/97 (97%), thus permitting intraoperative SLN mapping and sentinel node biopsy of at least 1 lymph node in 88 cases/94 (94%). Failure of the SLN procedure was noted in 9 cases: in 3 cases, no lymph node was individualized by LS, in 1 patient, intraoperative SLN mapping failed to find the previously identified SLN and in 5 cases, a SLN was identified by LS and intraoperative mapping but could not be removed because of its deep location and difficulty of dissection. In 17 patients, removal of one or two "non sentinel lymph node(s)" was (were) made by the surgeon because of its (their) suspected aspect (black or large). Among the 88 patients who had dissection of at least 1 SLN, a micrometastasis was detected by standard histological evaluation and/or immunohistochemical stains in 14 cases (16%) and into a "non SLN" in 2 cases (2,3%). The median follow up of patients was 16 months (1- 48 months). Among the 14 patients with positive SLN, 6 (43%) relapsed. The other eight were in complete remission of their melanoma with a mean follow up of 11,44 months . Among the 74 patients with negative SLN, 7 (9,5%) developed a recurrence. Among the 9 patients in whom any sentinel lymph node have been removed, 3 had a relapse (one in transit than on lymph nodes, and two on lymph nodes).

CONCLUSION

Our results are in accordance with the literature, and confirm the feasibility of SLN mapping and of SLN histological analysis in our center. We described in this study technical problems we encountered. Our study also show the prognostic value of this technique. However, advantage in global survey of sentinel node dissection and regional lymph node dissection in cases of micrometastases has still to be demonstrated.

Histological features of melanoma sentinel lymph node metastases associated with status of the completion lymphadenectomy and rate of subsequent relapse

BACKGROUND

The current recommendation for patients with cutaneous melanoma and a positive sentinel lymph node (SLN) biopsy is a completion lymph node dissection (CLND). This study sought to define a population of SLN-positive patients, based on their histological pattern of SLN metastases, who may not require CLND.

METHODS

All patients with SLN-positive cutaneous melanoma who underwent CLND between March 1999 and December 2004 at a single academic institution were enrolled. Metastatic deposits in the SLN were categorized by their histological zone of involvement (subcapsular, parenchymal and/or sinusoidal). Logistic regression was used to examine the effect of SLN zone, size of nodal metastases, and other histological factors on CLND positivity. Kaplan-Meier and Cox models were used to study disease recurrence.

RESULTS

A total of 127 patients were included, and 15.8% had positive non-sentinel nodes. In adjusted analyses, the size of the largest tumor deposit in the SLN was the only factor associated with CLND status. No patients with a tumor deposit <or=0.20 mm had a positive CLND. Although a specific zone of tumor involvement was not predictive of CLND status, involvement of all three zones was independently associated with increased recurrence. Size of the largest tumor deposit was also associated with recurrence, with no recurrences in patients with nodal deposits <or=0.20 mm.

CONCLUSION

Histologic features of tumor metastases in positive SLN may be useful in defining a population of patients who may be spared CLND and a group at high risk of recurrence.

Intraoperative lymphatic mapping and sentinel lymph node biopsy using radioactive tracer in gastric cancer

BACKGROUND

Gastric cancer continues to be a significant health problem around the world. Surgical resection with a lymph node dissection remains the only potentially curative treatment with gastric cancer. Determination of the extent of lymph node dissection required on the basis of actual node involvement in patients with gastric cancer is important as less extensive dissection may reduce postoperative morbidity and mortality rates. The current study examines the feasibility and reliability of sentinel lymph node biopsy in gastric cancer.

METHODS

A total of 32 patients who underwent gastrectomy with extended lymphadenectomy were enrolled in this study. A total volume of 148 MBq (2 mL) technetium-99m-radiolabeled, filtered sulphur colloid solution was injected into the primary lesion under gastroscopy 2 hours before the operation. Lymph nodes were examined as soon as possible by a hand-held gamma probe during the operation, without significant manipulation of the stomach or greater omentum. A sentinel lymph node (SLN) was defined by a level of radioactivity 10 times higher than the background.

RESULTS

Thirty-one of 32 patients had successful SLN biopsy, with a success rate of 97%. The sensitivity, specificity, positive predictive value, and negative predictive value of SLN biopsy were 100%, 95%, 90%, and 100%, respectively.

CONCLUSIONS

SLN biopsy using gamma probe in gastric cancer is a feasible procedure with high sensitivity and accuracy. This technique may be of a great benefit to surgeons in planning the extend of lymph node dissection in gastric cancer.

Evidence-based principles and practices in pathology: selected problem areas

Contrary to the intuitive impression of most pathologists, there are still many areas in laboratory medicine where evidence-based medicine (EBM) principles are not applied. These include aspects of both anatomic and clinical pathology. Some non-EBM practices are perpetuated by clinical "consumers" of laboratory services, because of inadequate education, habit, or over-reliance on empirical factors. Other faulty procedures are pathologist-driven, with similar underpinnings. This overview considers several exemplary problem areas representing non-EBM practices in the hospital laboratory. Such examples include ideas and techniques centering on metastatic malignancies, "targeted" oncological therapy, analysis of surgical margins in the excision of neoplasms, general laboratory testing and data utilization, evaluation of selected coagulation defects, administration of blood products, and analysis of hepatic iron-overload syndromes. The concepts illustrating departures from EBM are discussed for each of those topics.

Is a lymph node detected by the dye-guided method a true sentinel node in gastric cancer?

PURPOSE

A sentinel node is defined as the initial lymph node, to which cancer cells metastasize from a primary tumor. Recently, sentinel node navigation surgery has been done using the dye-guided method. However, no study has shown that a lymph node detected by the dye-guided method is the true sentinel node from the viewpoint of micrometastasis. Micrometastases of lymph nodes, in which no metastasis was found by H&E staining, were examined to establish whether a lymph node detected by the dye-guided method is the true sentinel node.

EXPERIMENTAL DESIGN

Isosulfan blue was injected endoscopically as the dye-guided method at a submucosal lesion of early gastric cancer. Total 345 lymph nodes, including 150 blue-dyed lymph nodes and 195 nondyed lymph nodes were collected from 57 patients and each was quartered. Two quarters were examined histologically by H&E staining and cytokeratin staining. The other specimens were used for quantitative reverse transcription-PCR of CEA and CK20 mRNAs.

RESULTS

Lymph node disease was not found in any of 345 lymph nodes from the 57 patients by routine H&E staining. By contrast, either CEA or CK20 mRNA expression was detected in 21 of 345 lymph nodes obtained from the 10 (18%) of 57 patients by quantitative reverse transcription-PCR. Eight of the 21 micrometastasis-positive lymph nodes were confirmed to be positive for cytokeratin staining. Although micrometastasis of nondyed lymph nodes was found in three cases, these were included in the 10 cases with micrometastasis of blue-dyed nodes, such that there was no patient who only had micrometastasis in nondyed nodes. Six of 10 cases were micrometastasis-positive in a single node; all six were blue-dyed nodes.

CONCLUSION

A lymph node detected by the dye-guided method should be a true sentinel node to which cancer cells metastasize initially.

The sentinel node concept in head and neck cancer: solution for the controversies in the n0 neck?

BACKGROUND

The majority of patients with head and neck squamous cell carcinoma (HNSCC) who have a clinical N0 neck undergo neck dissection (ND) even though no lymph node metastases may be detected. With this background, our investigation critically analyzes the value of sentinel lymphadenectomy.

METHODS

Ninety patients with HNSCC, all staged with an N0 neck, underwent intraoperative 99mTc-radiolabeled detection of up to three hot nodes (SN1-3) during elective ND and primary site resection.

RESULTS

Sentinel lymphadenectomy (SN1-3) detected occult metastatic spread in 20 (22%) of 90 patients, whereas failure occurred in three of 90 patients. Metastatic spread was directed to level II in the majority (66.7%) of cases. If only the SN1 had been examined, the procedure would have failed in nine (39%) of 23 patients.

CONCLUSION

Sentinel lymphadenectomy correctly identified the stage of metastatic disease in 97% of patients in cases in which up to three sentinel nodes were identified. If only the lymph node with the highest tracer activity had been excised, 39% of cancer-positive necks would have been missed. Selective ND identified metastatic disease in the additional 3% of patients.

Reassessing the role of lymphatic mapping and sentinel lymphadenectomy in the management of cutaneous malignant melanoma

Lymphatic mapping and sentinel lymphadenectomy was developed as a minimally invasive technique to provide regional lymph node staging information for patients at high risk for metastatic melanoma, but without clinically palpable disease. Only patients who demonstrate micrometastases undergo complete regional lymphadenectomy, sparing approximately 80% of patients the expense and morbidity of an elective lymph node dissection. This technique has been widely accepted as the preferred method to determine the pathologic status of the regional lymph nodes and the staging information gained is incorporated into the latest version of the American Joint Committee on Cancer staging system for cutaneous melanoma. Still, there is much controversy as to the use of this technique as a staging procedure and its overall therapeutic benefit in the treatment of patients with melanoma. Currently ongoing clinical trials will determine if lymphatic mapping and sentinel lymphadenectomy directly influences overall survival for patients with malignant melanoma. We review the latest technical aspects of this procedure and discuss the controversies surrounding its use.

Nodal staging in localized melanoma. The experience of the Brescia Melanoma Unit

BACKGROUND AND OBJECTIVES

We report our experience with patients affected by cutaneous melanoma undergoing sentinel node (SN) biopsy.

METHODS

From November 1997 to October 2000 we performed 128 selective lymphadenectomies (SN biopsy) on 127 patients with cutaneous melanoma with Breslow thickness>1 mm or regression or ulceration. Age, sex, tumour location ad histology were recorded.

RESULTS

Two hundred and thirty eight SNs were identified by lymphoscintigraphy in 167 lymphatic stations, 236 of them were identified intraoperatively using a gamma probe and patent blue V injection. Twenty-one patients had SNs with melanoma metastases (15.8%), 12 patients in the groin, eight patients in the axilla and one patient in the neck. After therapeutic lymphadenectomy eight more lymph nodes with metastases of melanoma were found in the specimens of three patients. After a follow-up ranging from 10 to 56 months the results are that 111 patients are free of disease. Ten patients died. Three patients have visceral metastases and are alive. One patient has developed two more melanomas. One patient was lost to follow-up.

CONCLUSIONS

Our data confirm the clinical reliability of the SN technique in melanoma; for optimisation of the therapeutic strategy, this technique might be considered the standard method of nodal staging in the evaluation of melanoma patients.

Sentinel node biopsy: not only a staging tool?

The management of clinically negative regional lymph nodes in early-stage melanoma has been controversial for at least a century. While some surgeons offer elective lymph node dissection (ELND), others recommend treatment of the primary alone and only perform a therapeutic dissection (TLND) for cases of recurrence in the nodal basin. The rationale for ELND is based on the concept that metastases occur via the sequential passage of tumor from the primary site to the regional lymph nodes and then to more distant sites. If this theory is correct then early dissection of the regional lymph nodes will disrupt the metastatic cascade and prevent further spread of disease. On the other hand, advocates of the "wait and watch" approach suggest that metastases to the regional lymph node basin are only a marker of disease progression and that distant disease can occur in the absence of lymph node metastases. Four randomized prospective studies have examined the efficacy of ELND versus TLND. While all four studies have failed to demonstrate a survival advantage of ELND, there is some suggestion that patients with metastases in the regional basin may benefit from ELND. As an alternative approach to this controversy, Morton and associates at the John Wayne Cancer Institute devised the technique of intraoperative lymphatic mapping and sentinel lymphadenectomy (LM/SL). This minimally invasive operative procedure allows the surgeon to identify the first or sentinel lymph (SN) in the regional basin. The technique is predicated on accurate mapping of the cutaneous lymphatics by lymphoscintigraphy and the intraoperative use of a vital blue dye to lead the surgeon to the SN and allow the pathologists to identify metastases in the lymph nodes. Patients with tumor-positive dissections would undergo complete lymph node dissection (CLND), and for those without metastases the complications and costs associated with CLND could be avoided. The success of the procedure depends on the completion of a learning phase and on the cooperation of nuclear medicine physicians, surgeons, and pathologists. While this technique has become almost standard practice in the United States and around the world, we await the results of several important clinical trials to determine whether LM/SL will replace ELND or the wait and watch approach in the management of early-stage melanoma.

Sentinel node detection in N0 cancer of the pharynx and larynx

Neck lymph node status is the most important factor for prognosis in head and neck squamous cell carcinoma. Sentinel node detection reliably predicts the lymph node status in melanoma and breast cancer patients. This study evaluates the predictive value of sentinel node detection in 50 patients suffering from pharyngeal and laryngeal carcinomas with a N0 neck as assessed by ultrasound imaging. Following 99m-Technetium nanocolloid injection in the perimeter of the tumour intraoperative sentinel node detection was performed during lymph node dissection. Postoperatively the histological results of the sentinel nodes were compared with the excised neck dissection specimen. Identification of sentinel nodes was successful in all 50 patients with a sensitivity of 89%. In eight cases the sentinel node showed nodal disease (pN1). In 41 patients the sentinel node was tumour negative reflecting the correct neck lymph node status (pN0). We observed one false-negative result. In this case the sentinel node was free of tumour, whereas a neighbouring lymph node contained a lymph node metastasis (pN1). Although we have shown, that skipping of nodal basins can occur, this technique still reliably identifies the sentinel nodes of patients with squamous cell carcinoma of the pharynx and larynx. Future studies must show, if sentinel node detection is suitable to limit the extent of lymph node dissection in clinically N0 necks of patients suffering from pharyngeal and laryngeal squamous cell carcinoma.

The role of sentinel lymph node biopsy for melanoma

Regional lymph nodes are a common site of melanoma metastases, and the presence or absence of melanoma in regional lymph nodes is the single most important prognostic factor for predicting survival. Furthermore, identification of metastatic melanoma in lymph nodes and excision of these nodes may enhance survival in a subgroup of patients whose melanoma has metastasized only to their regional lymph nodes and not to distant sites. Sentinel lymph node (SLN) biopsy was developed as a low morbidity technique to stage the lymphatic basin without the potential morbidity of lymphedema and nerve injury. The presence or absence of metastatic melanoma in the SLN accurately predicts the presence or absence of metastatic melanoma in that lymph node basin. When performed by experienced centers, the false-negative rate of SLN biopsy is very low. As such, the nodal basin that contains a negative SLN will usually be free of microscopic disease. Since occult micrometastatic disease affects only 12% to 15% of patients with melanoma, selective SLN dissection allows up to 85% of patients with melanoma to be spared a formal lymph node dissection, thus avoiding the complications usually associated with that procedure. While standard pathologic evaluation of lymph nodes may miss metastatic melanoma cells, more sensitive techniques are developing which may identify micrometastases more accurately. The clinical significance of these micrometastases remains unknown and is the subject of active investigations.

Improved staging of node-negative patients with intermediate to thick melanomas (>1 mm) with the use of lymphatic mapping and sentinel lymph node biopsy

BACKGROUND

Elective lymph node dissection (ELND) may contribute to a survival benefit in certain stratified subsets of melanoma patients. We hypothesized that lymphatic mapping and sentinel lymph node (SLN) biopsy (with complete node dissection if metastases are present) may improve both staging and survival of patients with clinically negative nodes, without subjecting all patients to the morbidity associated with complete ELND.

METHODS

We reviewed the data for all 14,914 N0 patients of the AJCC Melanoma Staging Database to determine the effect of SLN biopsy and ELND on staging and survival.

RESULTS

Retrospective analysis revealed that there was an apparent statistically significant survival advantage to SLN biopsy in patients with melanomas > 1 mm (n = 9024; 68.5% and 26.2% reduction in mortality compared with patients staged to be N0 by clinical exam and ELND, respectively; P < .0001). Five-year survivals were 90.5%, 77.7%, and 69.8%, respectfully, for patients staged by SLN biopsy (n = 2552), ELND (n = 2014), and clinical examination alone (n = 5192). The survival advantage of SLN biopsy was statistically significant for each T-stage category (T2, T3, and T4) and ulceration status. There was no advantage to SLN biopsy in patients with melanomas <1 mm (n = 5890).

CONCLUSIONS

SLN biopsy provides more accurate staging and may contribute to a survival benefit in populations of patients with melanoma.

Value of sentinel lymphonodectomy in head and neck cancer patients without evidence of lymphogenic metastatic disease

OBJECTIVE

Only few communications deal with the value of sentinel node (SN) biopsy for head and neck squamous cell carcinoma (HNSCC). Based on the results of 38 investigated patients with clinically N0-neck the feasibility of SN biopsy in HNSCC is critically discussed.

PATIENTS AND METHODS

Thirty-eight previously untreated patients with clinically N0-neck were staged by intraoperative SN biopsy. After intraoperative identification of the hottest node (SN(1)) and further less tracer accumulating lymph nodes (SN(2), SN(3)), patients were treated by different types of neck dissection (ND), adjusted to the location and extent of the primary tumour. Postoperatively the histologic results of the SN(1-3) and the entire ND specimen were compared.

RESULTS

The stage of cervical metastatic disease was demonstrated by a disease-free SN(1) in 32 patients. In five patients an isolated metastasis could be proven in the intraoperatively identified SN(1), while in the remaining patient an isolated metastasis was found in the SN(2).

CONCLUSION

Intraoperative SN biopsy seems to be valuable for the detection of occult lymph node metastases in HNSCC. This method might help to limit the extent of ipsilateral ND, if used as an intraoperative staging procedure to investigate the first draining tracer accumulating lymph nodes (SN(1-3)).

Evaluation of micrometastases in sentinel lymph nodes of cutaneous melanoma: higher diagnostic accuracy with Melan-A and MART-1 compared with S-100 protein and HMB-45

Accurate diagnosis of micrometastases in sentinel lymph nodes of cutaneous melanoma is critical for proper clinical management. S-100 protein and HMB-45 are the traditional immunomarkers widely used for this purpose. However, the interpretation of micrometastases by these markers is difficult with significant reduction in the diagnostic accuracy. S-100 protein demonstrates immunoreactivity for other nonmelanoma cells and obscures nuclear details, which are crucial for the interpretation of single cell metastases. We compared the new melanoma markers, Melan-A (clone A103) and MART-1 (clone M2-7C10), with S-100 protein and HMB-45, by examining 77 formalin-fixed paraffin-embedded sections of sentinel lymph nodes from 13 cases of primary cutaneous melanoma. CD68 (PG-M1) and hematoxylin-eosin-stained sections were also studied. Four pathologists interpreted the staining pattern after concealing the identity of each immunomarker. Az values (area under receiver operating characteristic curve) with receiver operating characteristic curve were higher with Melan-A (0.9742) and MART-1 (0.9779) compared with S-100 protein (0.8034) and HMB-45 (0.8651), demonstrating a higher diagnostic accuracy with Melan-A and MART-1 with superior detection of melanoma micrometastases. Melan-A and MART-1 showed sharp cytoplasmic immunoreactivity, almost exclusively restricted to the melanoma cells. Therefore, Melan-A and MART-1 are recommended for the evaluation of micrometastases in sentinel lymph nodes of cutaneous melanoma as a routine alternative to S-100 protein and HMB-45.

Carbon dye histologically confirms the identity of sentinel lymph nodes in cutaneous melanoma

BACKGROUND

False-negative results from lymphatic mapping and sentinel lymphadenectomy (LM/SL) are associated with technical failures in nuclear medicine and surgery or with erroneous histologic evaluation. Any method that can confirm sentinel lymph node (SN) identity might decrease the false-negative rate. Carbon dye has been used as an adjunct to assist lymphadenectomy for some tumors, and the authors hypothesized that it could be used for the histologic verification of SNs removed during LM/SL. The current study assessed the clinical utility of carbon dye as a histopathologic adjunct for the identification of SNs in patients with melanoma and correlated the presence of carbon particles with the histopathologic status of the SNs.

METHODS

LM/SL was performed using carbon dye (India ink) combined with isosulfan blue dye and sulfur colloid. Blue-stained and/or radioactive lymph nodes (two times background) were defined as SNs. Lymph nodes were evaluated for the presence of carbon particles and melanoma cells. If an SN lacked carbon dye in the initial histologic sections, four additional levels were obtained with S-100 protein and HMB-45 immunohistochemistry. Completion lymph node dissection (CLND) was performed if any SN contained melanoma cells.

RESULTS

One hundred patients underwent successful LM/SL in 120 lymph node regions. Carbon particles were identified in 199 SNs from 111 lymph node regions of 96 patients. Sixteen patients had tumor-positive SNs, all of which contained carbon particles. The anatomic location of the carbon particles within these tumor-positive SNs was found to be correlated with the location of tumor cells in the SNs. The presence of carbon particles appeared to be correlated with blue-black staining (P = 0.0001) and with tumor foci (P = 0.028). All 35 non-SNs that were removed during LM/SL were tumor-negative, and only 2 contained carbon particles. Of the 272 non-SNs removed during CLND, 5 contained metastases; 3 of these 5 were the only non-SNs that had carbon particles. The use of carbon particles during LM/SL was found to be safe and nontoxic.

CONCLUSIONS

Carbon dye used in LM/SL for melanoma permits the histologic confirmation of SNs. Carbon particles facilitate histologic evaluation by directing the pathologist to the SNs most likely to contain tumor. The location of carbon particles within SNs may assist the pathologist in the detection of metastases, thereby decreasing the histopathologic false-negative rate of LM/SL and subsequently reducing the same-basin recurrence rate.

Gamma probe-directed lymphatic mapping and sentinel lymphadenectomy in primary melanoma: Reliability of the procedure and analysis of failures after long-term follow-up

BACKGROUND AND OBJECTIVES

Some patients presenting with cutaneous malignant melanoma without palpable adenopathy have regional metastatic disease. The results of a prospective clinical study of gamma probe-directed sentinel lymph node (SLN) biopsy are presented.

METHODS

Over a 3-year period, 103 patients with a diagnosis of invasive primary cutaneous malignant melanoma (Breslow > 0.12 mm or > Clark level II) underwent preoperative lymphoscintigraphy with technetium sulfur colloid followed by gamma-probe-guided sentinel lymphadenectomy. There were 46 women and 57 men with a mean age of 55.7 years (range, 19-91).

RESULTS

Mean Breslow thickness was 2.3 mm (range, 0.12-10 mm). Primary locations were head and neck in 12, trunk 46, upper extremity 19, and lower extremity in 26. One hundred sixteen lymph node basins were mapped in 103 patients. Axillary, inguinal, and cervical nodal basins comprised 55, 34, and 11% of the total basins evaluated, respectively. Sixty-eight patients (66%) underwent lymphatic mapping of one regional nodal basin, 27 patients (26%) underwent synchronous lymphatic mapping of 2 regional nodal basins, 6 patients (6%) underwent synchronous lymphatic mapping of 3 regional nodal basins, and 2 patients (2%) underwent synchronous lymphatic mapping of 4 regional nodal basins. Seroma or infection did not occur in any patients. Micrometastatic disease was identified in 15 sentinel lymph node biopsy sites in 13 (10%) patients. Of 10 patients undergoing lymph node dissection, 9(90%) had no additional pathological lymph node involvement. We achieved 99% success rate, 1% rate of failed sentinel node procedure, and 8% false-negative rate after median follow-up for 2 years.

CONCLUSIONS

We concluded that gamma probe-directed sentinel lymph node biopsy is a straightforward procedure which can be done in the outpatient setting and facilitates management of patients with cutaneous malignant melanoma. It allows the surgeon to identify all basins at risk for metastatic disease and the location of the sentinel node(s) in relation to the basin.

Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of nonsentinel nodes following completion lymphadenectomy for melanoma

INTRODUCTION

Most melanoma patients with sentinel lymph nodes (SLN) that are histologically positive for metastasis have no additional positive lymph nodes found upon completion lymph node dissection (CLND). Therefore, it has been suggested that CLND may not be required for all patients with positive SLN. This study was undertaken to determine the frequency with which nonsentinel nodes contain melanoma cells detected by RT-PCR.

METHODS

Negative control lymph nodes were obtained from patients with breast and colon cancer. Positive control lymph nodes contained histologic evidence of melanoma. Nonsentinel nodes were harvested from melanoma patients undergoing CLND for a positive SLN. RT-PCR analysis for melanoma markers tyrosinase, gp100, MART-1, and MAGE-3 was performed, with Southern blot detection. The RT-PCR test was considered positive for the presence of melanoma cells if tyrosinase and at least one other marker were detected above background levels.

RESULTS

RT-PCR analysis detected the presence of melanoma cells in 0/100 (0%) of negative control lymph nodes and 28/29 (97%) of positive control lymph nodes. A total of 117 histologically negative nonsentinel nodes from 13 patients who underwent CLND for positive SLN were evaluated. RT-PCR analysis was positive in 18/117 histologically negative nonsentinel nodes (15%) from 7/13 patients (54%).

CONCLUSION

RT-PCR analysis suggests that when the SLN contains histologic evidence of melanoma, the remaining nodes in that basin are at risk for metastatic disease, despite the fact that these nonsentinel nodes are infrequently histologically positive.

Application of sentinel node biopsy to gastric cancer surgery

BACKGROUND

Sentinel node (SN) biopsy has been tried in the management of a variety of cancers with the hope that it would eliminate many unnecessary lymph node dissections, resulting in less morbidity. This important technique, however, has not been tried in gastric cancer surgery. The feasibility of SN biopsy and its accuracy in predicting the lymph node status in patients with gastric cancer were examined in the current study.

PATIENTS AND METHODS

SN biopsy was performed in patients with T1 (n = 44) or T2 (n = 30) gastric cancers (ie, immediately after laparotomy, indocyanine green was injected around the primary tumor, and the green-stained nodes [SNs: 2.6 +/- 1.7 nodes per patient] were removed). Then, gastrectomy with extended lymphadenectomy was performed. The unstained nodes (non-SNs: 39 +/- 18 nodes per patient) were obtained from the resected specimens. Both SNs and non-SNs were subjected to histologic examination with hematoxylin-eosin.

RESULTS

SNs could be identified in 73 of 74 patients (success rate, 99%). Of these 73 patients, 10 had lymph node metastases in SNs or non-SNs, or both; 6 in both SNs and non-SNs; 3 in SNs alone; and 1 in non-SNs alone. The sensitivity of the SN status in the diagnosis of the lymph node status of the patient was 90% (9/10) and specificity was 100% (63/63). Sensitivity was 100% in the T1 group (n = 44) and 88% in the T2 group (n = 29).

CONCLUSIONS

SN biopsy using indocyanine green can be performed with a high success rate, and the SN status can predict the lymph node status with a high degree of accuracy, especially in patients with T1 gastric cancer.

The role of sentinel lymph nodes in malignant melanoma

Selective sentinel lymph node dissection should be considered a standard approach in the treatment of primary malignant melanoma. With the combination of blue dye and radioisotope mapping, the sentinel lymph nodes (SLNs) can be harvested with pinpoint accuracy. This article compares blue dye and radioisotope mapping techniques. Based on the clinical outcome data of selective sentinel lymph node dissection, micrometastasis to the SLNs carries a poor prognosis for patients with primary invasive melanoma.

Sentinel lymph node biopsy in malignant melanoma: a series of 100 consecutive patients

A consecutive cohort of 100 patients who had undergone sentinel lymph node biopsy (SLNB) was analysed retrospectively. Three areas were studied: success in finding the sentinel node(s); complications of the procedure; and extra costs incurred by SLNB. The sentinel node(s) were successfully identified in 98% of the lymph node basins biopsied. The overall complication rate was 33%. The additional cost of the procedure was estimated at 1420 pounds sterling per patient. SLNB can reliably identify the sentinel node. However there is a significant complication rate of the technique and considerable additional costs. SLNB requires further critical evaluation before it can be accepted as a standard treatment for patients with malignant melanoma.

Surgical Management of Malignant Melanoma Using Dynamic Lymphoscintigraphy and Gamma Probe-Guided Sentinel Lymph Node Biopsy: The Emory Experience

Sentinel lymph node (SLN) biopsy is revolutionizing the surgical management of primary malignant melanoma. It allows accurate nodal staging which targets patients who may benefit from regional lymphadenectomy and systemic therapy. This is a retrospective review of patients treated at Emory University for stage I and II malignant melanoma with gamma probe-guided SLN biopsy from 1/1/94 to 6/30/98. Three hundred sixty patients (males 228, females 132) were identified. Primary melanoma sites included: head and neck 58, trunk 148, and extremities 154 (upper 71, lower 83). Primary tumor staging was T1 9, T2 134, T3 153, and T4 64. SLNs were successfully identified in 99.7 per cent of patients and 98.9 per cent of nodal basins mapped. In 275 (76.6%) cases a single draining nodal basin was identified. In 84 (23.3%) cases there were multiple draining nodal basins. Positive SLNs were identified in 63 patients (17.5%). SLN positivity by tumor staging was T1 0 per cent, T2 9.0 per cent, T3 22.2 per cent, and T4 26.6 per cent. The overall recurrence rate was 11.9 per cent. Recurrences by SLN status were SLN+, 27 per cent, and SLN-, 8.8 per cent. Regional recurrence occurred in 7 (2.4%) of the 297 with negative SLN biopsies and 7 (11.1%) of the 63 with positive SLN biopsies. Dynamic lymphoscintigraphy and gamma probe-guided SLN localization was successful in more than 98 per cent of cases. Patients with negative SLN biopsies have a low risk of recurrence.

Detection of mycobacterial DNA in cervical granulomatous lymphadenopathy from formalin-fixed, paraffin-embedded tissue by PCR

Cervical tuberculous lymphadenitis is the most common form of inflammatory neck mass in Korea. The diagnosis of tuberculosis requires proof of the presence of Mycobacterium tuberculosis by acid-fast staining or bacterial growth in culture. However, these are often difficult in cervical tuberculous lymphadenitis. The aim of this study was to investigate the value of the polymerase chain reaction (PCR) technique for detection of mycobacteria in routinely processed tissue sections of cervical granulomatous lymphadenopathy. In this retrospective study, twenty formalin-fixed, paraffin-embedded biopsy specimens from clinically and/or histopathologically diagnosed cervical granulomatous lymphadenopathy were analyzed for mycobacterial DNA by PCR. Two different primers to amplify mycobacterial-common 383-base pair (bp) DNA and Mycobacterium tuberculosis-complex-specific 123-bp DNA were used. Positive PCR products were sequenced directly. Mycobacterial-common DNA (383-bp positive) was found in 10 of the 20 cases. Among them, 7 cases were PCR positive with both primer sets. These seven cases can be considered as tuberculosis. The other three cases indicated possible atypical mycobacteriosis. PCR is a useful technique for the demonstration of mycobacterial DNA fragments in patients with clinically suspected cervical tuberculous lymphadenitis who have acid fast-negative histology and/or unsuccessful mycobacterial cultures.

Successful mapping of lymphorrhea using patent blue dye after lymph node dissection for malignant melanoma

Patent blue is a dye that has been used for intraoperative lymphatic mapping. We used this mapping method on a patient with lymphorrhea after groin dissection. We easily detected the lymphatic channel causing lymphorrhea and successfully ligated it. This technique may have great merit for treating of lymphorrhea.

Melanoma. A multidisciplinary approach for the general surgeon

Advances in the understanding of the biology and treatment of melanoma have moved the care of melanoma patients into an increasingly multidisciplinary environment. Surgeons must understand these advances because they will often be responsible for directing the overall care of these patients. Most patients with melanomas more than 1 mm in diameter and no evidence of metastatic disease should be offered SLNB to more accurately stage them and direct decisions about participation in postoperative adjuvant therapy trials. Until the results of the MSLT are known, the effect of SLNB and ELND on outcome remains unknown. SLNs should be analyzed with serial sectioning and immunohistochemistry to avoid missing micro-metastatic disease. Based on the results of the ECOG-1684 trial, the FDA approved IFN-alpha 2b for the adjuvant treatment of melanoma patients with thick primary tumors (> 4 mm) or resected nodal disease. IFN-alpha 2b treatment is expensive and potentially toxic. The data from ECOG-1684 do not support the use of IFN-alpha 2b in patients with node-negative disease. In light of the ECOG-1690 trial results, the role of high-dose IFN-alpha 2b in the management of patients with resected nodal disease is considerably less clear. Any recommendations for treatment with high-dose IFN-alpha 2b should be made only after weighing the costs, side effects, and potential benefits for individual patients. Numerous, less toxic, promising, adjuvant immunotherapeutic strategies have been developed and are being tested in multicenter, prospective, randomized trials. These strategies include GMK, PMCV, and Melacine. If the results of any of these trials show a survival advantage compared with placebo or equivalent survival compared with IFN-alpha 2b, these immunotherapeutic agents will become the adjuvant treatment of choice for patients with resected high-risk melanoma. RT-PCR detection of tyrosinase in SLNs can identify patients with submicroscopic nodal disease who may be at increased risk for recurrence or death from melanoma. An ongoing, prospective, randomized trial will determine whether patients with histologically negative but RT-PCR-positive SLNs will benefit from lymphadenectomy or adjuvant IFN-alpha 2b therapy. RT-PCR can also identify minimal residual disease in peripheral blood and bone marrow from patients with high-risk melanoma, but RT-PCR analysis of peripheral blood and bone marrow is still experimental, and procedural details need to be standardized and prospectively validated in large patient groups before its use can be considered the standard of care.

Sentinel node detection in malignant melanoma

The initial application of intraoperative lymphatic mapping and sentinel lymphadenectomy followed by selective complete lymphadenectomy (LM/SL/SCLND) was in melanoma. This arose as a solution to the ongoing debate concerning immediate vs. delayed lymph node dissection. Acceptance of the concept and advances in nuclear medicine, surgery, and pathology aspects of the sentinel node procedure have brought it into widespread use for melanoma and have expanded its application for other solid tumors that progress through the lymphatic route. Although the diagnostic accuracy of the procedure has been demonstrated in multicenter trials, caution should be exercised regarding therapeutic aspects until definitive benefit can be shown from well-designed clinical trials. Current issues of active discussion and debate are reviewed including ideal nomenclature, clinical significance of occult metastatic disease, quality assurance, and the role of LM/SL/SCLND outside high-volume melanoma centers.

The pathologist's role in sentinel lymph node evaluation

Patients with high-risk (thick, deeply invasive) primary melanoma were, in the past, managed by wide local excision and elective node dissection or wide local excision alone, with subsequent lymphadenectomy if the regional nodes developed clinically detectable metastases. We recently developed a more logical approach called selective lymph node dissection. To be effective, this requires close collaboration of surgeons, pathologists, and nuclear medicine physicians. The draining lymph node basin is identified preoperatively by lymphoscintigraphy. During surgery, a marker dye (isosulfan blue) and radioactive technetium labeled albumin are injected intradermally around the primary melanoma and the afferent lymphatics are followed up to the first lymph nodes of the ipsilateral regional nodal basin. The surgeon excises the blue-colored and maximally radioactive sentinel nodes and the pathologist critically evaluates these for the presence of a metastatic tumor. If the sentinel nodes are tumor free, no further nodal dissection is undertaken; if a tumor is present, a complete dissection of the nodal basin is performed. We have examined 1,119 sentinel lymph nodes from 669 patients treated by selective lymph node dissection. We identified melanoma cells in sentinel nodes from 126 patients (17.8%). A single node contained tumors in 67% of patients, 2 nodes were positive in 25%, and the remaining 12% of patients had three tumor-containing nodes. Melanoma cells were dispersed singly or in variably sized groups, usually in the peripheral nodal sinus. In around 40% of patients, immunohistochemistry is required to identify minute numbers of tumor cells. With experience, pathologists identify tumors in hematoxylin and eosin (H&E) preparations in an increasing proportion of lymph nodes. Tumor cells are more frequent in the sentinel nodes of patients with primary tumors of deeper Clark level and greater Breslow thickness. Tumor cells must be discriminated from capsular nevus cells, interdigitating dendritic leukocytes, macrophages, and intranodal neural tissues.

The concept of sentinel node localization: how it started

Intraoperative lymphatic mapping and sentinel lymphadenectomy (LM/SL) followed by selective complete lymphadenectomy (SCLND) has revolutionized the management of the regional lymph node basin in patients with solid tumors. Many investigators over the centuries have contributed to the understanding of the progression of tumor cells through the lymphatic system. This article discusses the conceptual background for the development of LM/SL in the original model of melanoma. The sentinel node hypothesis has been validated by a multicenter clinical trial showing that LM/SL in melanoma can be accurately performed in a uniform manner by multidisciplinary teams at cancer centers worldwide. Although the diagnostic and prognostic accuracy of LM/SL has been established, demonstration of the therapeutic use of this procedure awaits analysis of survival data from the multicenter randomized trial of wide excision alone versus wide excision plus LM/SL/SCLND.

Intraoperative lymphatic mapping and the sentinel node concept in colorectal carcinoma

BACKGROUND

Orderly progression of nodal metastases has been described for melanoma and breast cancer. The first draining lymph node, the sentinel node, is also the first to contain metastases and accurately predicts nodal status. The aim of this study was to assess the feasibility of lymphatic mapping and sentinel node biopsy in colorectal cancer.

METHODS

In 50 patients with colorectal cancer patent blue dye was injected around the tumour. After resection of the tumour the specimen was examined to identify blue-stained lymph nodes. Routine histopathological examination was performed on all nodes and the blue, haematoxylin and eosin-stained tumour-negative nodes were tested immunohistochemically.

RESULTS

Lymphatic mapping was possible in 35 of 50 patients (70 per cent). Pathological examination with haematoxylin and eosin staining showed lymph node metastases in 20 of 35 patients. In eight of these 20 patients the blue nodes showed tumour, while in 12 the blue nodes were not involved. This represents a false-negative rate of 60 per cent.

CONCLUSION

Lymphatic mapping using patent blue dye is feasible in colorectal cancer. The blue-stained nodes do not predict nodal status of the remaining lymph nodes in the resected specimen. The concept of lymphatic mapping and sentinel node identification is not valid for colorectal cancer.

Sentinel lymph node biopsy and axillary staging of T1-T2 N0 breast cancer: a multicenter study

From December 1996 to May 1998, 84 T1-T2 NO breast cancer patients were recruited for a multicenter study on the lymphoscintigraphic search of the axillary sentinel lymph node (SLN). The SLN was searched intraoperatively with a sodium iodide hand-held gamma-detecting probe (GDP) and excised before the standard axillary dissection was performed. Lymphoscintigraphy was unsuccessful in 8 of 84 cases (9.5%). In 73 of 76 patients with positive lymphoscintigraphy, SLN were found and excised (96%). The SLN proved to be predictive of axillary status in 71 of 73 cases (97.2%). Thirty of 41 patients had axillary metastases: in 16 cases, the SLN was the only site of the metastases (50%). In two cases, the SLN (reactive) did not match with the axillary status (2 of 63 reactive SLN, 4.6% of "skip" metastases). Age, tumor diameter, and histology seem to have little importance in affecting the predictivity of SLN biopsy. These results demonstrate the applicability of the lymphatic mapping techniques to a multicenter setting.