Sentinel node biopsy in patients with cutaneous melanoma of the head and neck

Biopsy of head and neck sentinel nodes (SNs) can be technically problematic due to the unpredictable and variable drainage patterns of this anatomic region. The aim of the present study was to evaluate the feasibility of SN biopsy for cutaneous melanoma of the head and neck. We performed SN biopsy in 17 patients affected by stage I cutaneous melanoma of the head and neck on the basis of lymphoscintigraphy, blue dye and gamma probe. A total of 24 procedures were performed. Drainage to more than one lymphatic basin was observed in five patients (two basins in three cases and three basins in two cases) and in all cases SN biopsy was performed in all basins. The biopsy distribution by site was: six cervical nodes, five parotid nodes, four supraclavicular and submandibular nodes, three auricular and axillary nodes. The SN identification rate was 87.5% (21/24); metastases were discovered in four cases, with a positivity rate of 23.6%. At the time of writing, 1 patient is alive with local disease, 3 patients are dead and 13 are alive and free of disease with a follow-up ranging from 1 to 40 months (median, 21 months) following SN biopsy. In our opinion preoperative lymphoscintigraphy and the intraoperative use of a gamma probe are useful for the identification of lymphatic drainage of cutaneous melanoma of the head and neck.     

Sentinel node localization in primary melanoma: learning curve and results

Ninety primary melanoma patients were studied to investigate the importance of adopting the simultaneous use of patent blue dye (PBD) and lymphoscintigraphy plus gamma detection probe to locate the sentinel node (SN). In total 135 SNs in 105 basins were visualized preoperatively under a gamma camera after lymphoscintigraphy. When a SN was identified intraoperatively, its radioactivity level and colour were verified and documented. Two of the SNs seen on lymphoscintigraphy were not found. Using PBD 78.52% of the SNs were identified; 95.5% were identified using the gamma detection probe. Using both methods together 98.5% of the SNs were detected. Twenty-two patients (24.4%) had pathologically positive SNs. The surgical learning curve was assessed for the two techniques. The learning curve associated with the methodology was important in finding the SN when using PBD associated with lymphoscintigraphy, but not when the gamma detection probe was used; we found a statistically significant reduction in the percentage of stained SNs found using PBD in the initial 14 SNs biopsied compared with the subsequent 121 nodes. This is important as not all institutions have access to a gamma probe. The time required to identify each SN was documented and analysed. The duration of the procedure was significantly shorter for stained SNs than for non-stained SNs, which support the use of both PBD and the gamma probe. In conclusion, SN biopsy should be performed by surgeons and nuclear medicine doctors in co-operation, both methods being adopted simultaneously to reduce the percentage of procedure failures.     

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 microL 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 authors. 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.     

Radioisotopic lymphatic mapping of the sentinel node in melanoma: importance of immunohistochemistry

BACKGROUND: Elective lymph node dissection (ELND) for patients with malignant melanoma is still controversial. A possible alternative could be biopsy of the first tumor draining lymph node, the sentinel node (SN), which can be identified by means of radionuclide techniques. AIM: Our study was undertaken to assess the accuracy of lymph node biopsy and to stress the importance of immunohistochemistry (IHC) in the pathological assessment of the SN for improved staging of the primary tumor. METHODS: We performed lymphoscintigraphy (LS) in 183 melanoma patients (89 with melanoma of the legs, 11 of the arms and 83 of the trunk). Our protocol consisted of preoperative peritumoral i.d. injection of 99mTc-labeled microcolloid to define the regional lymphatic basin and identify the sentinel node by means of planar scintigraphy. In 147 of the 183 cases a gamma probe (GP) was used during surgery to trace the SN. Vital blue dye was used during surgery in all cases. The SNs were excised for pathological examination. The pathological status of the SN was defined by means of examination of frozen sections, hematoxylin-eosin staining and immunohistochemistry for S-100 and HMB-45 MAb. RESULTS: At least one separate focus of activity was identified by LS in 182 out of 183 patients; in all 147 cases where a GP was used, it was successful in tracing the SN. LS with cutaneous mapping of the SN successfully guided the surgical excision in 177 of the 183 cases; in the 7 remaining cases, i.e. 7 out of 83 cases with SNs in the axillary basin, GP was not used and no elective node dissection was performed. Metastases were found in 39 of these 177 cases. In all 39 cases the SNs were the only positive nodes in the basin. Of the 39 metastases 18 were identified by means of frozen section, 12 by means of hematoxylin-eosin, and 9 by means of immunohistochemistry. We therefore emphasize the importance of immunohistochemistry in the pathology of LS for improved staging of the primary tumor.     

Lymphoscintigraphy and gamma probe tracing in detecting breast cancer lymph node involvement: can they replace axillary lymph node dissection?

BACKGROUND: Axillary lymph node status is the most important pathological determinant of prognosis in early breast cancer. However, axillary lymph node dissection (ALND) performed for pathological assessment is not without costs and morbidity. Recently, radioisotope-guided sentinel node biopsy (SNB) has been proposed as a promising technique for staging breast cancer patients. AIM OF THE STUDY: In this study we report our experience (76 patients) in radioguided sentinel node (SN) biopsy in breast cancer. The study was divided into two phases: the first represents our learning curve, necessary to establish our guidelines for its use in clinical practice, while the second phase was aimed at assessing the feasibility of SN localization using preoperative lymphoscintigraphy and intraoperative gamma probe (GP) detection. METHODS: All patients underwent lymphoscintigraphy (LS) up to two hours after tracer delivery (99mTc-micro-nanocolloid, four i.d. injections of 200 microCi/200 miccroL around the primary lesion) 24 hours before surgery and GP tracing during surgery. Subsequently ALND was performed for pathological assessment. RESULTS: SNs were identified in 73/76 patients using LS and in 72/76 using GP. In one case the SN was detected by GP alone while in two cases GP was not able to locate the SN although it had been identified by means of LS. Thirty-three of these 73 patients had axillary node involvement. In 31/33 cases the SN was the only positive node. No positive nodes were found in the remaining 40 ALNDs where SNs were identified. Thus, according to our experience 40/73 ALNDs could have been avoided. SNB seems to be a very interesting technique but further experience in lymph node radioisotope tracing is needed.     

Nuclear medicine aspects of melanoma and breast lymphatic mapping

A successful sentinel lymph node biopsy (SLNB) procedure in melanoma or breast cancer patients requires an accurate map of the pattern of lymphatic drainage from the primary site. Lymphoscintigraphy (LS) can provide such a map in each patient. This requires an understanding of lymphatic physiology, an appropriate small particle radiocolloid, high resolution collimators, and imaging protocols that detect all sentinel nodes (SNs) in every patient regardless of their location. The SN is not always found in the nearest node field and is best defined as "any lymph node receiving direct lymphatic drainage from a primary tumor site." Patterns of lymphatic drainage from the skin are not clinically predictable and unexpected drainage has been found from the skin of the back to SNs in the triangular intermuscular space or through the posterior body wall to SNs in the paraaortic, paravertebral, and retroperitoneal areas. Drainage from the head and neck is to unexpected nodes in 30% of patients. Upper limb drainage can be to SNs above the axilla. Interval nodes are not uncommon as SNs, especially on the trunk. Lymphatic drainage may involve SNs in multiple node fields and drainage across the midline of the body is quite common. In the breast, although 94% of patients have a SN in the ipsilateral axilla, 46% also have SNs outside the axilla, especially in the internal mammary chain (40%). Failure to biopsy all SNs in each patient thus has the potential to understage a significant number of patients with breast cancer. Micrometastatic disease can be present in any SN regardless of its location, and for the SLNB technique to be accurate a biopsy most be performed on all true SNs in every patient. LS is an important first step to ensure this goal is achieved.     

Detection of sentinel nodes by lymphoscintigraphy and gamma probe guided surgery in vulvar neoplasia

BACKGROUND: Pathologic lymph node status is the most important prognostic factor in vulvar cancer; however, complete inguinofemoral node dissection is associated with significant morbidity. Intraoperative lymphoscintigraphy associated with gamma detecting probe-guided surgery has proved to be reliable in the detection of sentinel node (SN) involvement in melanoma and breast cancer patients. The present study evaluates the feasibility of the surgical identification of inguinal sentinel nodes using lymphoscintigraphy and a gamma detecting probe in patients with early vulvar cancer. METHODS: Technetium-99-labeled colloid human albumin was administered perilesionally in 44 patients. Twenty patients had T1 and 23 had T2 invasive epidermoid vulvar cancer; one patient had a lower-third vaginal cancer. An intraoperative gamma detecting probe was used to identify SNs during surgery. Complete inguinofemoral node dissection was subsequently performed. SNs underwent separate pathologic evaluation. RESULTS: A total of 77 groins were dissected in 44 patients. SNs were identified in all the studied groins. Thirteen cases had positive nodes: the SN was positive in all of them; in 10 cases the SN was the only positive node. Thirty-one patients showed negative SNs: all of them were negative for lymph node metastasis. CONCLUSIONS: Lymphoscintigraphy and SN biopsy under gamma detecting probe guidance proved to be an easy and reliable method for detection of SNs in early vulvar cancer. If these preliminary data will be confirmed, the technique would represent a real progress towards less aggressive treatment in patients with vulvar cancer.     

Lymphoscintigraphy in clinical routine practice: Reproducibility and accuracy in melanoma patients with a long-term follow-up

Introduction

The sentinel node status is the most important single factor determining overall survival for patients with localized melanoma. Preoperative lymphoscintigraphy (LS) is essential in locating the correct sentinel lymph node (SN) and the reproducibility of the method determines the accuracy of the sentinel node biopsy (SNB). This study aims at determining the reproducibility and accuracy of LS in routine clinical practice after long-term follow-up.

Patients and methods

One hundred and eight melanoma patients with clinically unpredictable lymphatic drainage were prospectively enrolled to undergo two LS. The first LS was performed to determine the site and number of the lymphatic basins to plan SNB anesthesia and the second preoperative LS was to allow SN localization intra-operatively.

Results

Lymphatic drainage was demonstrated in all patients. In 84 of 108 cases, both LSs were concordant in terms of site and number of nodal basins visualized. After a median follow-up of 80 months, no nodal recurrence was observed in the five patients with a decreased number of lymph node basins. In the group with increased number of lymph node basins, one patient developed nodal metastases in the same regional lymph node basin visualized by both LS studies.

Conclusion

LS is an accurate and reproducible method to determine the localization of the sentinel node in the day-to-day routine to clinical practice when primary melanoma is also located in body sites with variable lymphatic drainage.     

Lymphatic mapping and sentinel node biopsy for melanoma

Worldwide experience has now confirmed that the histological status of sentinel nodes (SNs) accurately reflects the status of regional lymph nodes in patients with melanoma. Preoperative lymphoscintigraphy has proved to be invaluable in identifying SNs and in demonstrating unusual lymphatic drainage pathways. Greatest accuracy at the time of surgery is achieved using both blue dye injection and a gamma-probe. Close cooperation between surgeons, nuclear medicine physicians and pathologists is required if the SN biopsy technique is to be reliable. The results of clinical trials will demonstrate whether SN biopsy has any therapeutic value. It is already clear, however, that SN examination provides very accurate staging, and SN biopsy is therefore essential for all melanoma patients entering adjuvant therapy trials.     

Lymphatic mapping and sentinel node biopsy for melanoma

Worldwide experience has now confirmed that the histological status of sentinel nodes (SNs) accurately reflects the status of regional lymph nodes in patients with melanoma. Preoperative lymphoscintigraphy has proved to be invaluable in identifying SNs and in demonstrating unusual lymphatic drainage pathways. Greatest accuracy at the time of surgery is achieved using both blue dye injection and a γ-probe. Close cooperation between surgeons, nuclear medicine physicians and pathologists is required if the SN biopsy technique is to be reliable. The results of clinical trials will demonstrate whether SN biopsy has any therapeutic value. It is already clear, however, that SN examination provides very accurate staging, and SN biopsy is therefore essential for all melanoma patients entering adjuvant therapy trials.     

Sentinel node guided surgery for melanoma in the head and neck region

Sentinel lymph node biopsy may be more technically challenging for melanoma of the head and neck compared with other locations because of the complex lymphatic drainage patterns. This study demonstrates the value of sentinel node biopsy for head and neck melanoma, and highlights the associated difficulties. Thirty consecutive patients with primary cutaneous melanoma of the head and neck (n=26) or draining to the neck (n=4) underwent preoperative lymphoscintigraphy. This was followed by intraoperative lymphatic mapping using blue dye alone (n=8) or in combination with a hand-held gamma probe (n=22) and sentinel lymphadenectomy. Modified neck dissection was performed in all patients with positive sentinel nodes. The study population had a male predominance (73%). Most lesions were nodular and were not ulcerated. In two patients (6.2%) preoperative lymphoscintigraphy failed to demonstrate the draining nodes, which were retrieved by surgery, and in two patients (6.2%) the sentinel node was not found at surgery despite preoperative visualization. Overall, the sentinel node was identified 93% of the time: in seven out of eight cases (88%) using blue dye alone, and in 21 out of 22 cases (96%) using a combination of blue dye and gamma probe. Four out of 28 basins were deemed positive for metastases. Twenty-three of the 24 patients with negative sentinel nodes were free of disease at a median of 31 months (range 9-91 months). There was one false-negative case salvaged by surgery. The sentinel node technique is technically demanding but advantageous for most patients with head and neck melanoma. Identification rates seem to be better when preoperative lymphoscintigraphy is combined with intraoperative blue dye mapping and a hand-held gamma probe. The relative contribution of each component could not be determined.     

Is there any role for sentinel node mapping in colorectal cancer staging? Personal experience and review of the literature

BACKGROUND: We explored the role of lymphatic mapping and sentinel lymphadenectomy (originally described for melanoma and breast cancer) in colon cancer. Pathologic techniques can successfully identify micrometastatic disease in lymph nodes, but they are not suitable for clinical routine use. We evaluated the role of sentinel node (SN) mapping in refining the staging of colorectal cancer. METHODS: A total of 56 open colorectal resections were performed, and Patent Blue V dye was injected under the serosa surrounding the tumor immediately after opening the abdomen. SNs were analysed by immunohistochemistry to find micrometastatic disease. A literature search for the role of SNs in colorectal cancer was also performed. RESULTS: We identified the SN in 100% of patients, with a mean of 2.02 SNs/patient (range 1-5). After immunohistochemical staining, we could upstage 21 out of 56 patients (37.5%), and we observed 10.7% false negative SNs (6/56 patients). Fewer than half of the articles described false negative rates of <15%, and most articles showed an upstaging rate of >5% of patients. These differences are probably the result of different sensitivities of the methods used in identifying the lymph node micrometastases. CONCLUSIONS: SN mapping is an easy and cost-effective technique that holds promise and warrants further investigations.     

Role of routine preoperative lymphoscintigraphy in sentinel node biopsy for breast cancer

Sentinel node biopsy (SNB) is rapidly emerging as the preferred technique for nodal staging in breast cancer. When radioactive colloid is used, a preoperative lymphoscintiscan is obtained to ease sentinel lymph node (SN) identification. This study evaluates whether preoperative lymphoscintigraphy adds diagnostic accuracy to offset the additional time and cost required. 823 breast cancer patients underwent SNB based on lymphoscintigraphy, intraoperative gamma probe detection, and blue dye mapping using 99 mTc-nanocolloid and Patent Blue V injected peritumourally. The SNB was followed by standard axillary treatment at the same operation. Preoperative lymphoscintigraphy was performed around 3 h after the radioisotope injection. Preoperative lymphoscintigraphy revealed SNs in 593 (72%) of the 823 patients imaged. SN visualisation on lymphoscintigraphy was less successful in large tumours and tumours involving the upper outer quadrant of the breast (P=0.046, P<0.001, respectively). Lymphoscintigraphy showed internal mammary sentinel nodes in 9% (62/707) patients. The SN was identified intraoperatively in 98% (581) patients who had SN visualised on preoperative lymphoscintigraphy, with a false-negative rate of 7%. In patients who did not have SN visualised on preoperative lymphoscintigraphy, the SN was identified at operation in 90% (204) patients, with a false-negative rate of 7%. The SN identification rate was significantly higher in patients with SN visualised on preoperative lymphoscintigraphy (P<0.001). SN identification rate intraoperatively using the gamma probe was significantly higher in the SN visualised group compared with the SN non-visualised group (95% vs. 68%; chi square (1 degrees of freedom (df)) P<0.001. There was no statistically significant difference in the false-negative rate and the operative time between the two groups. A mean of 2.3 (standard deviation (SD) 1.3) SNs per patient were removed in patients with SN visualised on preoperative lymphoscintigraphy compared with 1.8 (SD 1.2) in patients with no SN visualised on lymphoscintigraphy (P<0.001). Although SN visualisation on preoperative lymphoscintigraphy significantly improved the intraoperative SN localisation rate, SN was successfully identified in 90% of patients with no SN visualisation on lymphoscintigraphy. Given the time and cost required to perform routine preoperative lymphoscintigraphy, these data suggest that it may not be necessary in all cases. It may be valuable for surgeons in the learning phase to shorten the learning curve and in patients who have increased risk of intraoperative failed localisation (obese or old patients). A negative preoperative lymphoscintiscan predicts the inability to localise with the hand-held gamma probe. Therefore, if the SN is not visualised on lymphoscintigraphy then the addition of intraoperative blue dye is recommended to increase the likelihood of SN identification.     

Identification of sentinel node in breast cancer: comparison between peritumoral and periareolar injection of the radiopharmaceutical contrast medium

Axillary node status is the most important prognostic factor for patients with primary breast carcinoma. The sentinel node biopsy (SN) technique has received much attention as a possible alternative to axillary lymph node dissection. The aim of this study is to identify the sentinel node by periareolar and subdermal injection of the radiopharmaceutical in four points, independent of tumor topography and the presence of biopsies and/or previous surgery. The peritumoral injection technique was carried out for comparison purposes. This study was performed on 115 patients, divided into 2 groups: Group A (25 patients, peritumoral injection) and Group B (90 patients, injection in four points). All the SN biopsies were studied by both imprint cytology and H&E staining. Control axillary lymph-node dissection was followed in all patients from Group A and in these positive cases from Group B. Twenty-two out of the twenty-five (88%) SNs were identified in Group A. There was no false negative; the sensitivity and specificity were 100%. Eighty-two of the ninety (91.1%) SNs were identified in Group B. Lymphoscintigraphy showed radiopharmaceutical migration to axilla in 93.7% of the cases. Hotspot area was 10 to 100 times the intensity of the background radiation. Among the 92 cases with negative sentinel nodes at intraoperative examination (TP), the SN histopathology confirmed the absence of cancer cells in 89 patients, whereas 3 were positive for metastatic cells. This study shows that periareolar injection in four points seems to be a good lymphatic mapping method for SN identification. We suggest standardizing this site of injection to identify the SNs. More studies to confirm these findings are ongoing.     

Omitting axillary lymph node dissection in sentinel node negative breast cancer patients is safe: a long term follow-up analysis

PURPOSE: To evaluate the rate of axillary recurrences in sentinel node (SN) negative breast cancer patients without further axillary lymph node dissection (ALND). PATIENTS AND METHODS: Between October 1994 and November 1999, all SN negative breast cancer patients who did not underwent complete ALND were enrolled in this prospective study. SN biopsy was performed by using the triple technique which combines preoperative lymphoscintigraphy, intraoperative use of blue dye, and a handheld gamma probe to visualize and localize the SN. SNs were examined by standard hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC). During the first year after surgery all patients underwent clinical examination at 3 monthly intervals. This follow-up interval was prolonged to 6 month after the first year. RESULTS: From the 104 patients, 93 (89%) underwent breast-conserving therapy; all remaining patients were treated by modified radical mastectomy. In 91 cases a ductal carcinoma and in 13 cases a lobular carcinoma was diagnosed. One SN was removed in 80, two SNs in 18, and three SNs in 2 patients. Twenty patients received systemic therapy based on age and primary tumor characteristics. After a median follow-up of 57 month only one axillary recurrence was observed. During follow-up three patients developed distant metastases. One of these patient with metastases to the bone is alive with evidence of disease. The remaining two patients died 9 and 19 month after surgery. CONCLUSIONS: Our long term follow-up results indicate that survival is excellent (98%) and local axillary control is adequate (99%) after omitting ALND in a group of 104 SN negative breast cancer patients.     

Evaluation of sentinel node identification with isosulfan blue in gastric cancer.

AIMS: The aim of this study was to clarify whether the metastasis of gastric cancer can be detected by identifying the sentinel lymph nodes (SNs) using only lymphatic dye. METHOD: The study was based on 101 patients clinically diagnosed with T1 and T2 gastric cancer. Isosulfan blue was intraoperatively injected within the submucosal layer around the lesion through an endoscope and blue stained nodes (BNs) were identified as SNs and harvested. Standard radical gastrectomy with D2 lymphadenectomy was performed on all patients and SNs and other nodes were evaluated. RESULTS: Out of 101 patients, 21 had lymph-node metastases. The accuracy of SN identification was 97.0% (98/101) and the metastasis detection rate was 85.7% (18/21). With improvement of the manoeuvre in the latter 84 cases, the detection rate was elevated up to 100.0% (18/18), as was the accuracy (84/84). CONCLUSION: The sentinel concept using lymphatic dye is applicable to gastric cancer, but the identification of SNs with lymphatic dye requires some practice. Furthermore, the issue of intraoperative metastasis detection remains to be resolved.     

The role of preoperative ultrasound scan in detecting lymph node metastasis before sentinel node biopsy in melanoma patients

BACKGROUND AND OBJECTIVES: To evaluate the efficacy of preoperative ultrasound (US) scanning in identifying lymph node metastasis before sentinel node biopsy (SNB), we conducted a prospective study on 125 patients with primary cutaneous melanoma (CM). METHODS: We prospectively enrolled 125 patients with >1 mm thick CM and candidate for SNB. Preoperatively, patients underwent US scanning of regional lymphatic basins and FNA of suspected lymph nodes (LN). All patients underwent lymphatic mapping and SNB. RESULTS: Combined with fine-needle aspirate (FNA) of suspect LN, US scan allowed the correct preoperative detection of 12 out of 31 histologically positive lymphatic basins, specificity and sensitivity being 100 and 39%, respectively. The false negative rate (61%) was mainly linked to tumor deposits less than 2 mm in diameter, which can be considered the current spatial resolution limit of this technique. CONCLUSIONS: Preoperative US scan could reduce the number of SNB, thus avoiding the stress of this surgical procedure in approximately 10% of patients and reducing health care costs. As a non-invasive and relatively inexpensive technique, lymph node US scan can be part of the preoperative staging process of patients' candidate for SNB in order to avoid unnecessary surgical procedures.     

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.