Lymphatic mapping in management of patients with primary cutaneous melanoma

In patients with primary cutaneous melanoma, knowledge of regional lymph-node status provides important information on outlook. Evidence suggests that early removal of nodes that contain metastatic disease improves survival outcome. Lymphatic drainage occurs first to sentinel nodes, which are therefore the nodes most likely to contain metastatic disease. Lymphatic mapping with lymphoscintigraphy is important to identify reliably sentinel nodes for removal and thus establish the status of regional nodes. Mapping studies in patients with melanoma have provided new insights into lymphatic anatomy and have shown previously unsuspected drainage pathways, which have important implications for accurate identification and removal of sentinel nodes. Because it is impossible to predict the site or sites of sentinel nodes clinically in individual patients, routine preoperative lymphoscintigraphy is a prerequisite if reliable results are to be obtained from sentinel-node biopsy.     

The role of lymphoscintigraphy in the detection of lymph node drainage in melanoma

Lymphatic drainage of the skin cannot be predicted based on clinical guidelines developed more than 100 years ago. Approximately 30% of patients experience drainage from the skin to unexpected lymph node sites rather than those specified by these guidelines, and therefore these outdated assumptions should no longer be used to plan surgery. A possible survival benefit has been shown for the early detection and surgical removal of metastatic disease in the draining lymph nodes, and therefore, clinicians must obtain accurate lymphatic mapping for each patient who has intermediate thickness melanoma to plan appropriate surgical therapy. Lymphoscintigraphy can be used to accurately define the precise position of each true sentinel node in every patient, whether these nodes lie in a standard node field or in an unusual location. In this way, lymphoscintigraphy has a direct beneficial impact on the surgical management of patients who have melanoma.     

Radioguided sentinel lymph node biopsy in patients with malignant cutaneous melanoma: the nuclear medicine contribution

As for other solid tumors, malignant cutaneous melanoma drains in a logical way through the lymphatic system, from the first to subsequent levels. Therefore, the first lymph node encountered (the sentinel node) will most likely be the first to be affected by metastasis, and a negative sentinel node makes it highly unlikely that other nodes in the same lymphatic basin are affected. Sentinel lymph node biopsy distinguishes patients without nodal metastases, who can avoid nodal basin dissection with its associated risk of lymphedema, and those with metastatic involvement who might benefit from additional therapy. This procedure represents a significant advantage as a minimally invasive procedure, considering that only an average 20% of melanoma patients with Breslow thickness between 1.5 and 4 mm harbour metastasis in their sentinel node(s) and are therefore candidates to elective lymph node dissection procedures. The cells that originate cutaneous melanomas are located between dermis and epidermis, a zone that drains to the inner lymphatic network in the reticular dermis, in turn to larger collecting lymphatics in subcutis. Therefore, the optimal modality of interstitial administration of radiocolloids for lymphoscintigraphy and subsequent radioguided sentinel lymph node biopsy is through intradermal/subdermal injection. (99m)Tc-labeled colloids in various size ranges are equally adequate for radioguided sentinel lymph node biopsy in patients with cutaneous melanoma, depending on local experience and availability. For melanomas located in the midline area of the head, neck, and trunk, particular consideration should be given to ambiguous lymphatic drainage, which frequently requires interstitial administration virtually all around the tumor or surgical scar from prior excision of the melanoma. Lymphoscintigraphy is an essential part of radioguided sentinel lymph node biopsy because images are used to direct the surgeon to the sites of the node(s). The sentinel lymph node should have a significantly higher count than that of background (at least 10:1 intraoperatively). After removal of the sentinel node, the surgical bed must be reexamined to ensure that all radioactive sites are identified and removed for analysis. The success rate of radioguidance in localizing the sentinel lymph node in melanoma patients is about 98% in institutions where a high number of procedures are performed, approaching 99% when combined with the vital blue dye technique. The procedure is becoming the standard of care for patients with cutaneous melanoma because of its high prognostic value that has led to include the procedure in the most recent version of the TNM staging system.     

Sentinel node identification by scintigraphic methods in cutaneous melanoma

In melanoma patients lymph node metastasis is an important prognostic factor that indicates the need for therapeutic lymph node dissection. Preoperative lymphoscintigraphy mapping associated with radioguided sentinel lymph node biopsy has become a well established procedure for cutaneous melanoma patients without clinically detectable lymph node metastases (stage I, II). This technique is a versatile way of characterizing the lymphatic basin at risk for metastases and identifying involved lymph nodes. The purpose of the present study was to examine the reproducibility of lymphoscintigraphy and sentinel lymph node biopsy in detecting micro metastases in cutaneous melanoma. The study was a single-institution prospective analysis of 74 melanoma patients, with primary tumors having Breslow thickness > 0.7 mm, who underwent lymphoscintigraphies between May 2002 and September 2003. Technetium-99m sulfur colloid was injected intradermally at the primary tumor site and dynamic images were obtained for 40 minutes. Two observers evaluated the images. One to two weeks after the first lymphoscintigraphy, radioguided lymph node biopsy was performed. For the biopsy, technetium-99m sulfer colloid was injected intradermally in the same manner as performed before. Lymph nodes were identified and removed with the aid of a gamma ray detecting probe (GDP), and were submitted to histopathological analysis. The histopathological analysis of the sentinel lymph nodes collected during surgery was performed in a sequential manner. First, frozen sections were analyzed during surgery. The lymph nodes considered negative by frozen section were analyzed by H&E staining. Subsequently, the slides considered negative with H&E were sent for immunohistochemical analysis. Lymphoscintigraphy identified at least one sentinel lymph node in all patients. Sentinel node biopsy detected metastases in 20 patients (27.2%). In all cases the lymph node basins identified during lymphoscintigraphy were found to have at least one sentinel lymph node during surgery. Frozen section analysis of the lymph node was only able to identify the disease in 35% of the patients eventually found to have micrometastases with H&E and immunohistochemistry. Two lymph nodes were negative with H&E and positive with immunohistochemical analysis. In conclusion, lymphoscintigraphy is a simple procedure that is well tolerated by patients. It is useful in locating sentinel lymph nodes in patients with melanoma and is an important tool in the clinical practice of oncology. We recommend performing H&E, and if necessary, immunohistochemical analysis of all sentinel lymph nodes because of the high rate of false negative results with frozen sections alone.     

Implications of lymphatic drainage to unusual sentinel lymph node sites in patients with primary cutaneous melanoma

BACKGROUND: Sentinel lymphadenectomy reliably identifies the first site(s) of regional lymphatic drainage and, therefore, the most likely lymph nodes to contain occult metastasis in patients with primary cutaneous melanoma. Although in most patients lymphatic drainage from the primary melanoma first reaches a standard lymph node basin, a sentinel lymph node (SLN) may be identified in an unusual location. The objective of this study was to determine the frequency and significance of unusual sentinel lymph node drainage patterns in a large cohort of patients with primary melanoma. METHODS: The records of 1145 consecutive primary melanoma patients who underwent SLN biopsy were reviewed. Preoperative lymphoscintigraphy was performed in all patients with truncal melanoma and in many patients with distal extremity lesions. Unusual lymph node sites were defined as epitrochlear, popliteal, or ectopic/interval (in-transit or any other nonstandard lymph node-bearing area). RESULTS: At least one SLN was harvested in 1117 patients (98%). SLN biopsy of an unusual lymph node site was attempted in 59 patients (5%). Successful intraoperative localization and biopsy was performed in 54 (92%) of 59 patients for a total of 56 unusual sites. Of these, 7 (13%) were popliteal, 8 (14%) were epitrochlear, and 41 (73%) were ectopic/interval. Preoperative lymphoscintigraphy was performed in 41 of these 54 patients and correctly identified unusual SLN locations in 12 (29%); the majority of unusual SLNs were identified only with the assistance of the intraoperative gamma probe. In four patients (7%), the unusual lymph node site was the only site from which SLNs were harvested. In the remaining 50 patients (93%), biopsies were performed on SLNs from both unusual sites and from a standard lymph node basin. Among the 54 patients who underwent a SLN biopsy of an unusual nodal site, 7 (13%) had lymph node metastases in that location. In four of the seven patients, the only positive SLN was from the unusual site. CONCLUSIONS: Sentinel lymphatic drainage patterns include lymph node-bearing areas that may be outside established standard lymph node basins and may represent the only site of regional lymph node metastases. Although preoperative lymphoscintigraphy may assist in the identification of unusual SLN drainage patterns, intraoperative use of the gamma probe is recommended to identify accurately and completely all sites of regional lymph node drainage.     

Preoperative cutaneous lymphoscintigraphy in malignant melanoma

To identify the regional lymph node basins cutaneous lymphoscintigraphy with technetium 99m rhenium sulfide colloid (99mTc-ReS) was performed in 45 patients and with technetium 99m antimony sulfide colloid (99mTc-Sb2S3) in seven patients after excisional biopsy of the primary tumor. All patients had skin tumors located in the face or neck or on the trunk with 47 cases of cutaneous malignant melanoma and 5 cases of benign or premalignant lesions. In 48 patients the scintiscans 1 hour after perilesional injection of the tracer colloid clearly showed the lymphatic drainage patterns from the tumor sites, of them 25 patients demonstrated unidirectional drainage, whereas the remaining 23 patients had multidirectional drainage to two or three lymph node groups. There were technical difficulties in performing the examinations in four patients. The authors recommend cutaneous lymphoscintigraphy as a safe, simple and reliable technique for mapping the lymphatic drainage preoperatively in patients with Stage I cutaneous malignant melanoma of axial localization.     

Lymphatic mapping and sentinel lymph node biopsy in the management of primary cutaneous melanoma: report of a single-centre experience

AIMS AND BACKGROUND: Lymphatic mapping and sentinel lymph node biopsy provide important prognostic data in patients with early stage melanoma and are crucial in guiding the management of the tumor. We report our experience with lymphatic mapping and sentinel lymph node biopsy in a group of patients with primary cutaneous melanoma and discuss recent concepts and controversies on its use. PATIENTS AND METHODS: A total of 111 patients with stage I-II AJCC primary cutaneous melanoma underwent lymphatic mapping and sentinel lymph node biopsy from December 1999 through December 2004 using a standardized technique of preoperative lymphoscintigraphy and biopsy guided by blue dye injection in addition to a hand-held gamma probe. After removal, sentinel lymph nodes were submitted to serial sectioning and permanent preparations for histological and immunohistochemical examination. Complete lymph node dissection was performed only in patients with tumor-positive sentinel lymph nodes. RESULTS: Sentinel lymph nodes were identified and removed in all patients (detection rate of 100%), and metastases were found in 17 cases (15.3%).The incidence of metastasis in sentinel lymph nodes was 2.1%, 15.9%, 35.2%, and 41.6% for melanomas < or 1.0, 1.01-2.0, 2.01-4.0, and > 4.0 mm in thickness, respectively. Complete lymph node dissection was performed in 15 of 17 patients with positive sentinel lymph nodes, and metastases in non-sentinel lymph nodes were detected in only 2 cases (11.7%). Recurrences were more frequently observed in patients with a positive than in those with negative sentinel lymph node (41.1% vs. 5.3% at a median follow-up of 31.5 months, P < 0.001). The false-negative rate was 2.1%. CONCLUSIONS: Our study confirms that lymphatic mapping and sentinel lymph node biopsy allow accurate staging and yield relevant prognostic information in patients with early stage melanoma.     

Sentinel node-guided evaluation of drainage patterns for melanoma of the helix of the ear

The head and neck region, and especially the ear and its helix, is notorious for its ambiguous pattern of lymphatic drainage. Therefore, the primary nodal drainage basins in melanoma of the helix of the ear are often unpredictable. The aim of the study was to examine the value of sentinel lymph node biopsy in melanoma of the helix of the ear and to describe the natural history of the disease. Fifteen consecutive patients (14 men) with primary melanoma of the helix of the ear (median thickness, 1.2 mm; range, 0.7-10.0) underwent preoperative lymphoscintigraphy, followed by intraoperative lymphatic mapping, using blue dye in combination with a hand-held gamma probe and sentinel lymphadenectomy. The melanomas were characterized by low mitotic rate, low lymphocytic infiltrate, low spontaneous-regression rate, and mostly epitheloid cell type. In one patient, preoperative lymphoscintigraphy failed to demonstrate the draining nodes. The sentinel lymph nodes were identified and retrieved in all patients during surgery. In 13 patients (87%), they were found in the upper jugular lymphatic basin (level IIA); none were found in the retroauricular region. All sentinel lymph nodes were tumor-negative. At a median follow-up of 39 months (range, 12-73), all 15 patients were disease-free. In conclusion, sentinel lymph node biopsy for helix melanoma is an excellent alternative to elective lymph node neck dissection and superficial parotidectomy, with a high success rate and low morbidity. Melanoma of the helix of the ear has an indolent natural history.     

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.     

Sentinel lymphadenectomy in cutaneous melanoma

AIMS AND BACKGROUND: In the last ten years validation of the sentinel lymph node (SLN) concept has led to modification of the surgical approach for patients with intermediate-risk cutaneous melanoma. METHODS AND STUDY DESIGN: Forty-eight patients affected by cutaneous melanoma with a Breslow thickness between 0.65 and 4 mm were enrolled in the study. Approximately 2 mCi of radiotracer and 1 mL of vital blue dye were injected in each patient around the site of the primary lesion. Lymphoscintigraphy was performed until the lymphatic basin and the respective SLN were localized. The whole surgical procedure consisted of enlargement of the surgical margins followed by localization and excision of the SLN(s) by using both radiotracer and vital dye. Whenever the SLN proved to be histologically positive for metastasis, complete regional lymphadenectomy was performed. RESULTS: Within 15 minutes of radiotracer administration the lymphatic basin was localized in all 4 patients by lymphoscintigraphy. Vital dye and radiotracer successfully allowed SLN localization and excision in 46 of 48 patients (97%); in one case the SLN was detected by radiotracer alone. The SLN proved to be metastatic in six (13%) of 46 evaluable patients; interestingly, in three of them the presence of metastatic cells was revealed only by immunohistochemistry. All patients with tumor-positive SLNs had primary lesions with a Breslow thickness = 2 mm. CONCLUSIONS: Sentinel lymphadenectomy is able to identify lymph node involvement in patients with cutaneous melanoma with a Breslow thickness > 1 mm, thus avoiding the risks associated with radical regional lymphadenectomy. Lymphoscintigraphy proved to be an important tool to obtain correct preoperative localization of the drainage basin, especially for melanomas located on the face and trunk.     

Contrast-enhanced ultrasound: a filter role in AJCC stage I/II melanoma patients

One of the most significant advances in melanoma staging is sentinel lymph node biopsy (SLNB). It is a surgical technique to detect occult nonpalpable micrometastases in regional lymph nodes. Recently, contrast-enhanced ultrasound (CEUS) was introduced as a noninvasive procedure, in spite of SLNB, for the detection of SLNs in patients with cutaneous melanoma. The main purpose of this study was to evaluate the diagnostic accuracy of CEUS in the diagnostic workup of patients with melanoma in comparison with the final histology of SLNs detected through preoperative lymphoscintigraphy. Fifteen patients with cutaneous melanoma underwent prompt excisional biopsy with narrow margins in order to avoid impairment of the melanoma lymphatic basin and were referred for SLNB according to routine indications between January and February 2009. In our study CEUS showed, albeit based on a small patient sample, a negative predictive value of 100%, that means that all negative results were confirmed by negative SLN histopathological examination; all ultrasonographically negative lymph nodes corresponded to nonmetastatic sentinel nodes.     

Lymphatic mapping and sentinel node identification in squamous cell carcinoma and melanoma of the head and neck

AIM: The aim of our study was to evaluate the role of scintigraphy in lymphatic mapping and in the identification of the sentinel lymph node (SLN) in patients with head and neck cancer. METHODS: Between September 1999 and February 2001 we enrolled 22 consecutive patients with cancer in the head and neck region: five squamous cell carcinomas, one Merkel cell tumor of the cheek, and 16 malignant melanomas. Lymphoscintigraphy was performed three hours before surgery after injection of 30-50 MBq of 99mTc -Nanocoll in 0.3 mL; the dose was fractionated by injecting the radiotracer at two points around the lesion. Static acquisition (anterior and/or lateral views, 512 x 512 matrix, 5 mins pre-set time) was started immediately after the injections so as to visualize the pathways of lymphatic drainage. The skin projection of the SLN was marked with ink. Intraoperative SLN detection was performed with perilesional injection of patent blue. RESULTS: SLNs were found with lymphoscintigraphy in all patients. Thirty-three SLNs were identified: one occipital node, three nodes at the base of the tongue, 10 superficial lateral nodes (external jugular), five submandibular nodes, five submental nodes, three mastoid nodes and six supraclavicular nodes. Biopsy was performed in 21/22 patients. In 20/22 patients the first lymph nodes were visualized in the proximal cranial regions (retroauricular, jugular and submandibular) at five minutes post injection. The SLN positivity rate was 13.6% (three patients). All patients with tumor-positive SLNs were submitted to radical dissection. Poor concordance in the detection of sentinel nodes was observed with patent blue. CONCLUSIONS: The flow of nanocolloid in the lymph vessels of the head is rapid. In our experience immediate scintigraphic imaging was essential to visualize the pathways of lymphatic drainage and the first SLN. Radioguided SLN biopsy is therefore recommended within three hours. Injection of patent blue is inadvisable because of the poor concordance with lymphoscintigraphy and the risk of permanent tattooing of the face.     

Decisive role of SPECT/CT in localization of unusual periscapular sentinel nodes in patients with posterior trunk melanoma: three illustrative cases and a review of the literature

Sentinel node mapping is widely applied in patients with melanoma. Although this type of skin cancer usually drains to the standard regional nodal basins, some patients have drainage to an unpredicted site. Nodes lying along a lymphatic channel, between the primary melanoma site and a common basin, are often called interval, in-transit, ectopic, intercalated, or aberrant nodes. They must be considered sentinel lymph nodes because they receive direct lymphatic drainage from a primary tumor site. Most investigators agree that interval sentinel nodes should be harvested; however, the management of melanoma patients with an involved interval sentinel node without established metastasis in the regional basin downstream is controversial. New and innovating technologies have improved nuclear medicine images, including single-photon emission computed tomography/computed tomography (SPECT/CT), a multimodal technique that fuses the radioactivity distribution detected by SPECT with the anatomic information harvested by CT. SPECT/CT does not replace the conventional planar images; it should be considered as a complementary modality for the search of sentinel lymph nodes. We report three illustrative cases that underline the decisive role of SPECT/CT with two-dimensional and three-dimensional reconstruction images to localize the uncommon periscapular sentinel nodes in patients with melanoma of the posterior trunk. The use of this image fusion technique on these patients leads to improved preoperative visualization of the sentinel nodes, may help identify additional periscapular interval sentinel nodes, and enables precise localization of the nodes with their surrounding anatomic structures. The cases are discussed together with a review of the literature.     

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.     

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.     

乳腺癌淋巴引流途径的临床研究

目的探讨乳腺癌时乳腺淋巴引流的特点。方法以2004年11月至2006年5月期间住院的206例乳腺癌患者为研究对象，其中191例术前行淋巴闪烁显像。用前哨淋巴结活检和腋窝溶脂后腔镜观察联合验证淋巴闪烁显像所见的乳腺淋巴引流途径和前哨淋巴结。结果肿瘤周围腺体实质和肿瘤被覆皮下联合注射示踪剂内乳前哨淋巴结显示率为46．8％。淋巴显像、前哨淋巴结活检和腋窝溶脂后腔镜3种方法联合观察发现乳腺淋巴经不同输入淋巴管直接引流到腋窝或内乳区；腋窝前哨淋巴结位于第2肋骨与胸大肌外缘交界处周围，少数患者有浅、深两组腋窝前哨淋巴结。内乳淋巴结转移率为26．2％，腋窝淋巴结转移≥4枚时内乳转移率为50．7％。第2肋间隙是内乳淋巴结最常见的转移部位。内乳淋巴结转移与肿瘤部位或大小无显著相关性。结论乳腺实质及皮肤的淋巴沿各自的集合淋巴管不经乳晕淋巴丛而直接汇人腋窝或内乳淋巴结；多数患者不同的淋巴管在腋窝汇人同一前哨淋巴结，少数汇人深浅不同组前哨淋巴结。有选择地行内乳淋巴结活检有助于乳腺癌的精确分期、治疗和预后判断。     

Sentinel node biopsy in early vulvar cancer

Lymph node pathologic status is the most important prognostic factor in vulvar cancer; however, complete inguinofemoral node dissection is associated with significant morbidity. Lymphoscintigraphy associated with gamma-probe guided surgery reliably detects sentinel nodes in melanoma and breast cancer patients. This study evaluates the feasibility of the surgical identification of sentinel groin nodes using lymphoscintigraphy and a gamma-detecting probe in patients with early vulvar cancer. Technetium-99m-labelled colloid human albumin was administered perilesionally in 37 patients with invasive epidermoid vulvar cancer (T1-T2) and lymphoscintigraphy performed the day before surgery. An intraoperative gamma-detecting probe was used to identify sentinel nodes during surgery. A complete inguinofemoral node dissection was then performed. Sentinel nodes were submitted separately to pathologic evaluation. A total of 55 groins were dissected in 37 patients. Localization of the SN was successful in all cases. Eight cases had positive nodes: in all the sentinel node was positive; the sentinel node was the only positive node in five cases. Twenty-nine patients showed negative sentinel nodes: all of them were negative for lymph node metastases. Lymphoscintigraphy and sentinel-node biopsy under gamma-detecting probe guidance proved to be an easy and reliable method for the detection of sentinel node in early vulvar cancer. This technique may represent a true advance in the direction of less aggressive treatments in patients with vulvar cancer.     

Predicting lymphatic drainage patterns and primary tumour location in patients with breast cancer

Detailed knowledge of the lymphatic drainage of the breast is limited. Lymphoscintigraphy is a technique used during breast cancer treatment to accurately map patterns of lymphatic drainage from the primary tumour to the draining lymph nodes. This study aimed to create a statistical model to analyse the spread of breast cancer and primary tumour location using a large lymphoscintigraphy database, and visualise the results with a novel computational model. This study was based on lymphoscintigraphy data from 2,304 breast cancer patients treated at the Royal Prince Alfred Hospital Medical Centre in Sydney, Australia. Bayesian inferential techniques were implemented to estimate the probabilities of lymphatic drainage from each region of the breast to each draining node field, to multiple node fields, and to determine probabilities of tumour prevalence in each breast region. A finite element model of the torso and discrete model of the draining node fields were created to visualise these data and a software tool was developed to display the results (). Results confirmed that lymphatic drainage is most likely to occur to the axillary node field, and that there is significant likelihood of drainage to the internal mammary node field. The likelihood of lymphatic drainage from the whole breast to the axillary, internal mammary, infraclavicular, supraclavicular and interpectoral node fields were 98.2, 35.3, 1.7, 3.1, and 0.7%, respectively; whilst the probability of lymphatic drainage to multiple node fields was estimated to be 36.4%. Additionally, primary tumours are most likely to develop in the upper regions of the breast. The models developed provide quantitative estimates of lymphatic drainage of the breast, giving important insights into understanding breast cancer metastasis and have the potential to benefit both clinicians and patients during breast cancer diagnosis and treatment.     

Sentinel-node guided lymph-node dissection for merkel cell carcinoma.

Merkel cell carcinoma is an aggressive neuroendocrine skin tumour. Treatment is still debatable. Merkel cell carcinoma resembles malignant melanoma in its cutaneous presentation and its embryonic origin; both have unpredictable biological behaviour, early regional lymph node involvement, early distant metastases and a high recurrence rate. In light of these common features, we used pre-operative lymphoscintigraphy, intraoperative lymph-node mapping and sentinel-node biopsy-a well-described technique for the treatment of melanoma-in a 60-year-old man with Merkel cell carcinoma in the right buttock. Following frozen section identification of a metastatic first-order sentinel node, radical right groin dissection was performed. All the other lymph nodes in this basin proved to be disease-free, including the second-order sentinel node and Cloquet node. The patient is now being treated with adjuvant chemotherapy and radiotherapy. This case shows that sentinel-node guided dissection is applicable to Merkel cell carcinoma.     

Technetium antimony sulfur colloid scintiscan in selective lymph node dissection for malignant melanoma

Lymphoscintigraphy with Technetium antimony sulfur colloid (TASC) was used in four patients with malignant melanoma to identify the pattern of lymphatic drainage, allowing selective lymph node dissection. TASC is safe and predictive of lymph node drainage patterns. Using this technique allows visualization of multiple tiers of lymph nodes in 2 to 6 hours.