Localizing the sentinel node in cutaneous melanoma: gamma probe detection versus blue dye

Lymphoscintigraphy, sentinel lymph node biopsy, and Mohs micrographic surgery in the treatment of Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with a high incidence of occult nodal metastases. MCC is believed to be similar in natural history to thick or ulcerated melanomas in its propensity for locoregional recurrence and early lymph node metastasis. Studies have shown that nodal status is statistically correlated to survival in MCC. Radiolocalization and superselective lymph node biopsy is a recent technique that has been proven to be of great value in evaluating the status of occult lymph node disease in malignant melanoma and breast cancer patients.

OBJECTIVE

In previously untreated patients, an orderly progression of metastases is observed for both cutaneous carcinomas and malignant melanomas and is anticipated for MCC. METHODS/RESULTS. We present two patients with MCC of the head and neck who underwent simultaneous Mohs micrographic surgery and sentinel lymph node biopsy with intraoperative radiolocalization.

CONCLUSION

Sentinel lymph node biopsy and intraoperative lymphoscintigraphy may prove to be a useful technique in evaluating occult nodal involvement and in limiting the potentially unnecessary morbidity of more comprehensive lymph node dissections in MCC patients who do not yet have metastatic involvement.

Sentinel lymph node biopsy in patients with primary cutaneous melanoma: study of 455 cases

BACKGROUND

The role of elective lymph node dissection in the treatment of patients with primary melanoma is a debated topic in surgical oncology. However, recent data assure a survival improvement with this technique only for patients harbouring nodal metastases. The emergence of a new procedure of lymphatic mapping permits the identification of the sentinel lymph node (SLN), the first draining node from the site of cutaneous melanoma, which has demonstrated to be predictive of staging of the entire regional lymphatic basin and useful in selecting for lymph node dissection only those patients who have early micrometastases.

OBJECTIVES

To verify in a large series of cases whether a combination of preoperative lymphoscintigraphy and intraoperative mapping with both vital blue dye and a hand-held gamma probe would permit an increase of the rate of successful SLN localization up to 100%; to check the utility of a wider application of SLN biopsy in patients with thin melanomas owing to a favourable risk-benefit ratio; to determine the predictive value of SLN biopsy by performing regional lymphadenectomy in patients who have pathological evidence of metastases in the SLN; to observe whether the use of SLN technique and selective lymphadenectomy might improve the clinical evolution of patients and favour low rates of recurrence.

METHODS

In 425 AJCC stage I or II melanoma patients, preoperative lymphoscintigraphy by intracutaneous injection of Tc99m-labelled albumin nanocolloids around the tumour or the tumour's excision scar was combined with the intraoperative use of a hand-held gamma probe and patent blue V mapping technique, in order to identify and harvest the SLN. In five cases the blue dye was voluntarily not used because of previous allergic reactions. In other 25 preliminary cases the procedure was performed using the blue dye alone (10 cases) or combined with a preoperative lymphoscintigraphy (15 cases). A wide excision of the primary site was then undertaken in all cases. SLNs were sent to the pathologist for serial sectioning and permanent preparations with histological and immunohistochemical examination. Patients with pathological evidence of metastatic disease in SLN returned for regional lymphadenectomy.

RESULTS

The combined use of lymphoscintigraphy, blue dye and gamma probe allowed us to identify one or more SLNs in all cases except for two (99.5% rate of success). In 70 melanomas less than 0.76 mm thick, SLNs were negative for metastases, whereas in 380 patients with thicker tumours micrometastases were demonstrated in 75 cases (19.7%). In patients with SLN metastases who underwent regional lymph node dissection, no other metastases were found three times out of four. After a median follow-up period of 18 months the rate of recurrence of the disease in 335 patients with SLN free of metastasis was low (5.4%) with a very low regional nodal recurrence (1.2%). Moreover, the worsening of the disease did not exceed 18.5% of cases with metastasis in SLN.

CONCLUSIONS

Our data confirm in a large series of cases that the SLN biopsy is extremely selective and useful to find early micrometastases and to identify patients needing regional lymphadenectomy and adjuvant immunotherapy. Patients with intermediate thickness melanoma (0.76-4.0 mm) should be informed on the availability of such a revolutionary procedure, which represents a new opportunity in primary melanoma surgery.

Sentinel node biopsy for melanoma in the head and neck region

BACKGROUND

Lymphatic drainage in the head and neck region is known to be particularly complex. This study explores the value of sentinel node biopsy for melanoma in the head and neck region.

METHODS

Thirty consecutive patients with clinically localized cutaneous melanoma in the head and neck region were included. Sentinel node biopsy was performed with blue dye and a gamma probe after preoperative lymphoscintigraphy. Average follow-up was 23 months (range, 1-48).

RESULTS

In 27 of 30 patients, a sentinel node was identified (90%). Only 53% of sentinel nodes were both blue and radioactive. A sentinel node was tumor-positive in 8 patients. The sentinel node was false-negative in two cases. Sensitivity of the procedure was 80% (8 of 10).

CONCLUSIONS

Sentinel node biopsy in the head and neck region is a technically demanding procedure. Although it may help determine whether a neck dissection is necessary in certain patients, further investigation is required before this technique can be recommended for the standard management of cutaneous head and neck melanoma.

Sentinel node localization in primary melanoma: preoperative dynamic lymphoscintigraphy, intraoperative gamma probe, and vital dye guidance

BACKGROUND

Sentinel node (SN) biopsy can be used to select patients with primary melanoma for therapeutic lymphadenectomy. The aim of the study was to assess the efficacy of 3 methods to locate the SN: preoperative dynamic lymphoscintigraphy, intraoperative patent blue dye (PBD), and gamma-detecting probe (GDP).

METHODS

We studied 133 patients with cutaneous melanoma and clinically negative lymph nodes. Within 24 hours before surgery, colloid labeled with technetium 99m was injected intradermally around the site of the primary melanoma. The patients were studied before their operations by using dynamic lymphoscintigraphy. A total of 208 SNs were found in 164 lymph node basins. In addition, all the patients had PBD injected immediately before the surgical procedure. When the blue-stained node was identified intraoperatively, its radioactivity level was measured with the GDP. In the absence of blue coloration, the GDP was used to trace the SN.

RESULTS

Of 208 SNs, 168 (80.8%) were identified in the regional draining basin during intraoperative lymphatic mapping by using PBD. By using the GDP method, 202 (97.1%) of 208 were identified (GDP vs PBD; P < .01). By combining the 2 methods, 206 (99%) of 208 SNs were detected. Of the 133 patients, 29 (21.8%) had pathologically positive SNs, and were subsequently subjected to regional lymphadenectomy. In 26 (89.7%) of 29 patients, the SN was the only node with metastasis. Three cases (10.3%) of recurrence in patients with microscopic SN metastasis and 7 cases (6.7%) of recurrence in patients without SN metastasis were found during a median follow-up of 566 days.

CONCLUSIONS

Preoperative dynamic lymphoscintigraphy and intraoperative mapping with PBD and GDP offer simple and reliable methods of staging regional lymph nodes without subjecting every patient to a regional lymphadenectomy.

Radiopharmaceuticals for lymphoscintigraphy: including dosimetry and radiation considerations

The recognition of the importance of lymphoscintigraphy for identification of the sentinel lymph nodes in melanoma and breast cancer plays a significant role in the clinical management of these patients. The widespread clinical acceptance of this technique and the lack of an agreement on which radiopharmaceutical agent has the most ideal properties has resulted in a wide variety of agents being used clinically with other agents under investigation or development. This article reviews some of the physical properties that a radiopharmaceutical agent should possess and discusses in depth commonly used agents and lists some agents under development. This article also discusses the dosimetry and biological effects various radiopharmaceutical agents have for lymphoscintigraphy in melanoma and breast cancer patients. In view of the lack of a consensus agreement on which radiopharmaceutical agent will provide the optimal clinical information this article will provide an overview of potentially useful radiopharmaceutical agents and radiation dosimetry considerations.

Lymphatic mapping and sentinel lymphadenectomy after wide local excision of primary melanoma

BACKGROUND

Lymphatic mapping and sentinel lymphadenectomy (LM/SL) are generally avoided in patients who have already undergone wide local excision (WLE) of a primary melanoma, because of concern that disruption of the cutaneous lymphatics might alter lymphatic flow to the sentinel node. We reviewed carefully chosen patients who had undergone LM/SL after WLE to identify circumstances that might make this approach otherwise safe and clinically accurate.

STUDY DESIGN

From our melanoma database of 8,300 patients, of whom 1,015 had undergone LM/SL, we retrospectively identified 47 patients who had previously undergone WLE. Patient and tumor characteristics were collected and compared with followup data from clinic files.

RESULTS

Median WLE surgical margins before LM/SL were 2.0 cm and most patients had extremity lesions. Eleven of the 47 patients (23%) had tumor-involved sentinel nodes, and 8 of these patients (73%) had a solitary nodal metastasis. With a median followup period of 36 months, 3 sentinel node-negative patients developed nodal recurrences. Two of these patients had positive sentinel nodes on pathology re-review and were not considered failures of the lymphatic mapping surgical procedure. The third patient developed in-transit metastases and delayed nodal recurrence. An additional patient, who had a primary tumor on the trunk, developed a nodal recurrence in the basin opposite that identified by lymphoscintigraphy. The overall error rate of the technique was 4 in 36 (11%). This included 2 pathology misdiagnoses (5.6%), 1 nodal recurrence associated with in-transit regional metastases (2.8%), and 1 lymphatic mapping error (2.8%).

CONCLUSIONS

LM/SL can be cautiously performed in patients who have undergone previous WLE if the primary resection margin was no greater than 2.0 cm and the primary was not in a region of ambiguous drainage. Lymphatic mapping may be inaccurate when melanomas have been resected with large margins, especially if the wound was closed with rotation flaps, and when melanomas are on the head and neck or trunk regions.

Identification of sentinel lymph nodes in vulvar carcinoma patients with the aid of a patent blue V injection: a multicenter study

BACKGROUND

The aim of this multicenter study was to investigate the feasibility and negative predictive value of sentinel lymph node detection with blue dye in vulvar carcinoma patients.

METHODS

In patients with squamous cell carcinoma of the vulva without suspicious groin lymph nodes, patent blue V was injected intradermally shortly before surgery. Routine groin lymph node dissection and radical vulvectomy were performed. During the surgery, blue lymph vessels and lymph nodes were identified, and the blue lymph nodes were sent separately for histologic examination. The negative predictive value of the blue lymph nodes for the absence of metastases was assessed by histologic examination of the groin lymph node specimens.

RESULTS

Fifty-one patients in whom 93 groin lymph node dissections were performed were entered. One or more blue lymph nodes were detected in only 52 groins (56%). Nine (17%) of these were tumor positive, and 6 blue lymph nodes were the only tumor positive lymph nodes in the specimen in which they were found. There were two false-negative blue lymph nodes. The negative predictive value was 0.953.

CONCLUSIONS

It was shown in this multicenter study that sentinel lymph node detection in vulvar carcinoma patients with blue dye only is not feasible because its negative predictive value is too low. Further studies involving the use of a combination of radioactive labeled technetium and blue dye are warranted.

Recent advances in melanoma staging and therapy

BACKGROUND

Recent advances in the staging and treatment of melanoma were reviewed.

METHODS

A literature-based review was performed.

RESULTS

The current American Joint Committee on Cancer (AJCC) Staging system for melanoma has several drawbacks. Proposed changes in the staging system to take into account simplified tumor thickness categories, tumor ulceration, and the number (rather than size) of nodal metastases will allow stage groups with more uniform prognosis. The widespread application of sentinel lymph node biopsy for nodal staging allows accurate nodal staging with minimal morbidity. Reverse transcriptase-polymerase chain reaction (RT-PCR) is a very sensitive molecular staging test that may prove useful for identifying early metastatic disease. There is finally an effective adjuvant therapy for melanoma--interferon alfa-2b. Other adjuvant therapies, including melanoma vaccines, may provide effective and less toxic alternatives. New immunotherapy and gene therapy strategies are under investigation.

CONCLUSIONS

Ongoing and future adjuvant therapy trials will benefit from improved melanoma staging by accrual of homogeneous groups of patients. New approaches for adjuvant therapy await completion of clinical trials. Innovative new therapies offer hope for patients with advanced disease.

Carbon dye as an adjunct to isosulfan blue dye for sentinel lymph node dissection

BACKGROUND

The success of intraoperative lymphatic mapping depends on accurate identification of the sentinel node. We hypothesized that a carbon particle suspension would allow histopathologic confirmation of the sentinel lymph node through deposition of carbon within that node.

METHODS

An animal model was used to compare the lymphatic mapping accuracy of carbon dye with that of isosulfan blue dye, the standard agent for intraoperative visualization of the sentinel lymph node. Twenty-two rats underwent lymphatic mapping in each distal lower extremity with various combinations of carbon dye and isosulfan blue dye. All stained (blue or black) nodes in the inguinal drainage basin were removed for pathologic analysis, including carbon particle analysis. A meticulous search identified all nonstained (nonsentinel) nodes in the same basin. These nonsentinel nodes were examined for carbon particles by light microscopy. Dermal diffusion of mapping agents at the injection site was also recorded. Animals were then observed for 28 days to assess the toxicity of mapping agents.

RESULTS

Although isosulfan blue dye and full-strength carbon dye each stained all sentinel nodes, the latter obscured histologic detail. The combination of 2.5% carbon dye, 7.5% saline solution, and 90% isosulfan blue dye also stained all sentinel nodes; carbon particles were seen on light microscopy in all 13 stained nodes and did not interfere with histologic evaluation. No unstained node contained carbon particles, although the number of nonsentinel nodes was small. Carbon dye exhibited significantly less intradermal diffusion than isosulfan blue dye, but the carbon left a permanent mark on the skin. No toxicity or side effect associated with the use of carbon dye was observed.

CONCLUSION

Carbon dye allows histopathologic confirmation of sentinel lymph nodes identified by isosulfan blue dye.

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.

Positive iliac and obturator nodes in melanoma: survival and prognostic factors

BACKGROUND

The need for deep groin dissection when superficial nodes contain metastatic melanoma is controversial.

METHODS

A review of 362 therapeutic groin dissections performed at our tertiary referral center between 1961 and 1995 revealed 71 patients (20%) with positive iliac and/or obturator nodes. This group was analyzed for survival rates, prognostic factors for survival, regional tumor control, and morbidity.

RESULTS

Patients with involved deep nodes exhibited overall 5-year and 10-year survival rates of 24% (SE, 5%) and 20% (SE, 5%), respectively. Independent prognostic factors for survival were the number of positive iliac nodes (P = .0011), the Breslow thickness (P = .0069), and the site of the primary tumor (P = .0075). Patients with an unknown primary tumor seemed to have better prognoses. Seven patients (10%) experienced recurrence in the surgically treated groin. The short- and long-term morbidity rates (infection, 17%; skin flap necrosis, 15%; seroma, 17%; mild/ moderate lymphedema, 19%; severe lymphedema, 6%) compared well with those of other series studying inguinal as well as ilioinguinal dissections.

CONCLUSIONS

From the present study it can be concluded that removal of deep lymph node metastases is worthwhile, because one of every five such patients survives for 10 years. Prognostic factors for survival are the number of involved iliac nodes, the Breslow thickness, and the site of the primary tumor. Long-term regional tumor control can be obtained for 90% of the patients. The morbidity of an additional deep lymph node dissection is acceptable.

Technique of lymphatic mapping and sentinel node biopsy for melanoma

AIMS

An increasing number of surgeons perform sentinel node biopsy to identify melanoma patients with early lymphatic dissemination who may benefit from regional node dissection or adjuvant therapy. The addition of lymphoscintigraphy and intraoperative gamma-ray detection with a hand-held probe increases the sensitivity of the surgical technique substantially.

METHODS

The value of lymphoscintigraphy is discussed. The operative technique of lymphatic mapping and sentinel node biopsy is described, including the use of a vital dye and a gamma-ray probe.

CONCLUSIONS

Close to 100% of first-tier lymph nodes can be identified with this combined approach without the unnecessary removal of too many higher-echelon nodes.

Sentinel lymph node biopsy for melanoma

BACKGROUND

The most powerful predictor of survival for patients with melanoma is the status of the regional lymph nodes. Sentinel lymph node biopsy may provide improved staging accuracy without the morbidity of elective lymph node dissection (ELND).

METHODS

Sixty-eight patients with intermediate thickness melanoma underwent gamma probe guided sentinel node biopsy without ELND and were followed up over a mean of 22 months.

RESULTS

A sentinel node was found in all patients. Six patients (9%) had positive sentinel nodes; all underwent complete lymphadenectomy. Two patients (3%) with negative sentinel nodes developed nodal recurrence; 1 of these patients was found to have microscopic disease on reexamination of the sentinel node. Two patients (3%) developed systemic disease.

CONCLUSION

Gamma probe guided sentinel node biopsy can be performed with a high rate of technical success. It provides accurate pathological staging with a low incidence of nodal basin failure.

Identification and biopsy of the sentinel lymph node in breast cancer

AIMS

To examine the hypothesis that lymphatic dissemination in breast cancer occurs sequentially.

METHODS

Thirty patients with clinically localized adenocarcinoma were studied. Patent blue dye was administered into the tumour at the beginning of a modified radical mastectomy or segmental mastectomy with en bloc axillary lymph-node dissection (ALND). In the removed specimen, blue-stained lymphatic channels were dissected from the primary tumour to the first draining lymph node(s) (sentinel node(s)).

RESULTS

Identification of a sentinel node (SN) was successful in 26 patients (87%). In 10 patients the SN was tumour-positive. In six of these patients, the SN was the only tumour-positive node. There was no incidence of 'skip' metastasis.

CONCLUSIONS

This study confirms the sequential nature of lymphatic dissemination. When confirmed in vivo, these data may lead to a substantial reduction of the need for ALND without compromising survival and regional control and without loss of prognostic and staging information.

Immediate or delayed dissection of regional nodes in patients with melanoma of the trunk: a randomised trial. WHO Melanoma Programme

BACKGROUND

The use of elective regional node dissection in patients with cutaneous melanoma without any clinical evidence of metastatic spread is still debated. Our aim was to evaluate the efficacy of immediate node dissection in patients with melanoma of the trunk and without clinical evidence of regional node and distant metastases.

METHODS

An international multicentre randomised trial was carried out by the WHO Melanoma Programme from 1982 to 1989. The trial included only patients with a trunk melanoma 1.5 mm or more in thickness. After wide excision of primary melanoma, patients were randomised to either immediate regional node dissection or a regional node dissection delayed until appearance of regional-node metastases.

FINDINGS

Of the 252 patients entered, 240 (95%) were eligible and evaluable for analysis. 122 of these were randomised to immediate node dissection. 5-year survival observed in patients who had delayed node dissection was 51.3% (95% CI 41.7-60.1) compared with 61.7% (52.0-70.1) of patients who had immediate node dissection (p=0.09). 5-year survival rate in patients with occult regional node metastases was 48.2% (28.0-65.8) and 26.6% (13.4-41.8, p=0.04) in patients in whom the regional node dissection was delayed until the time of appearance of regional node metastases. Multivariate analysis showed that routine use of immediate node dissection had no impact on survival (hazard ratio 0.72, 95% CI 0.5-1.02), whilst the status of regional nodes affected survival significantly (p=0.007). The patients with regional nodes that became clinically and histologically positive during follow-up had the poorest prognosis.

INTERPRETATION

Node dissection offers increased survival in patients with node metastases only. Sentinel node biopsy may become a tool to identify patients with occult node metastases, who could then undergo node dissection.

Computed tomography for the detection of neck node metastases in melanoma patients

AIMS

To assess the value of CT scanning for detection of lymph node metastases in the neck.

METHODS

The appearance and site of the metastases was studied, as well as the sensitivity and specificity of CT.

RESULTS

Nodal metastases did not always show a high contrast uptake and nodal density therefore cannot be used as a criterion for metastasis. Irregular contrast enhancement was seen in seven of the 21 tumour-positive necks. Frequently, metastases in the parotids, superficial nodes in the neck and in the posterior triangle were seen. The sensitivity and specificity of palpation and CT scanning were 87 and 100%, respectively.

CONCLUSIONS

However, because small, clinically occult, melanoma metastases were frequently overlooked on CT, the role of this imaging modality in assessing occult metastases remains limited. Based on recent data from literature it is reasonable to speculate that ultrasound guided fine needle aspiration cytology (FNAC) will prove to be more effective than a non-invasive staging procedure of the neck in melanoma patients.

Principles and guidelines for surgeons: management of cutaneous malignant melanoma. European Society of Surgical Oncology Brussels

This article outlines and discusses the principles of the guidelines for the management of malignant melanoma by surgeons. The guidelines are based, in large part, on the consensus of the Dutch Melanoma Working Party that was revised in 1997. The article reflects internationally accepted treatment principles that have arisen both from critical assessment of existing evidence and data, and from the outcome of randomized studies.