Influence of fast lymphatic drainage on metastatic spread in cutaneous malignant melanoma: a prospective feasibility study

The concept of sentinel lymph node biopsy in cutaneous malignant melanoma is widely established. Preoperative cutaneous lymphoscintigraphic mapping is a reliable method for identifying the nodal basins at risk of metastases in melanomas. In this prospective study we investigated the correlation between the scintigraphic appearance time and the metastatic involvement of sentinel lymph nodes. In 276 malignant melanoma patients (137 women, 139 men; age 16-93 years), dynamic and static lymphoscintigraphy was performed after strict intracutaneous application of technetium-99m nanocolloid (40-150 MBq; 0.05 ml/deposit) around the tumour or biopsy scar. Analysis of dynamic scans primarily focussed on the appearance time of sentinel lymph nodes. Sentinel lymph node visualisation 20 min as slow drainage. Fast lymphatic drainage was found in 236 patients, of whom 34 (14.4%) had sentinel lymph node metastases. Twenty-two patients showed hybrid (fast and slow) lymphatic drainage, and eight (36.4%) of them had sentinel lymph node metastases. Seven of the latter demonstrated fast lymphatic drainage, while one showed one positive sentinel lymph node with fast and another with slow drainage. The melanomas of 18 patients demonstrated exclusively slow lymphatic drainage, in all cases without sentinel lymph node metastases. This prospective study indicates that the scintigraphic appearance time of sentinel lymph nodes seems to be a clinically relevant factor for prediction of metastatic spread of cutaneous malignant melanoma. Larger numbers of patients need to be examined to truly assess the benefit of the scintigraphic appearance time compared with other predictors of sentinel lymph node tumour positivity.     

Sentinel node detection and definition may depend on the imaging agent and timing.

PURPOSE: Two cases of sentinel lymph node imaging are presented in which the results are exceptions to what the literature generally defines as sentinel lymph nodes. In one case, Tc-99m antimony trisulfide colloid produced significantly different results than did Tc-99m tin colloid. In the second case, the results bring into question the definition of a sentinel node as the first in a lymphatic drainage pathway. MATERIALS AND METHODS: In one patient, lymphoscintigraphy was performed initially using Tc-99m antimony trisulfide colloid injected intradermally around a melanoma excision site. Repeated lymphoscintigraphy 1 month later, 1 hour before sentinel node excision, was done using Tc-99m tin colloid, a larger particle than antimony trisulfide colloid. The second patient, with a melanoma biopsied only, had sentinel node imaging performed using Tc-99m sulfide colloid, a particulate also larger than antimony trisulfide colloid and also 1 hour before sentinel node excision. RESULTS: In the first patient, imaging with the smaller antimony trisulfide colloid showed more lymphatic pathways and more sentinel nodes than with tin colloid. In the second patient, the first focus of retention of the imaging agent in the lymphatic pathway seen showed less intense accumulation than the next focus in the pathway, contrary to published reports that the sentinel node shows more intense accumulation than do nodes further downstream in a lymphatic pathway. CONCLUSIONS: There are exceptions to published characteristics of sentinel node lymphoscintigraphy, so care must be exercised in localizing sentinel nodes.     

Temporary shielding of hot spots in the drainage areas of cutaneous melanoma improves accuracy of lymphoscintigraphic sentinel lymph node diagnostics

Detection of the "true" sentinel lymph nodes, permitting correct staging of regional lymph nodes, is essential for management and prognostic assessment in malignant melanoma. In this study, it was prospectively evaluated whether simple temporary shielding of hot spots in lymphatic drainage areas could improve the accuracy of sentinel lymph node diagnostics. In 100 consecutive malignant melanoma patients (45 women, 55 men; age 11-91 years), dynamic and static lymphoscintigraphy in various views was performed after strict intracutaneous application of technetium-99m nanocolloid (40-150 MBq; 0.05 ml/deposit) around the tumour (31 patients) or the biopsy scar (69 patients, safety distance 1 cm). The images were acquired with and without temporary lead shielding of the most prominent hot spots in the drainage area. In 33/100 patients, one or two additional sentinel lymph nodes that showed less tracer accumulation or were smaller (<1.5 cm) were detected after shielding. Four of these patients had metastases in the sentinel lymph nodes; the non-sentinel lymph nodes were tumour negative. In 3/100 patients, hot spots in the drainage area proved to be lymph vessels, lymph vessel intersections or lymph vessel ectasias after temporary shielding; hence, a node interpreted as a non-sentinel lymph node at first glance proved to be the real sentinel lymph node. In two of these patients, lymph node metastasis was histologically confirmed; the non-sentinel lymph nodes were tumour free. In 7/100 patients the exact course of lymph vessels could be mapped after shielding. In one of these patients, two additional sentinel lymph nodes (with metastasis) were detected. Overall, in 43/100 patients the temporary shielding yielded additional information, with sentinel lymph node metastases in 7%. In conclusion, when used in combination with dynamic acquisition in various views, temporary shielding of prominent hot spots in the drainage area of a malignant melanoma of the skin leads to an improvement in the accuracy of identification and localisation of sentinel lymph nodes by lymphoscintigraphy.     

Role of nuclear medicine in melanoma

Melanoma is a malignant tumour of the melanocytes presenting characteristic metabolic and biological features, which remains a difficult and important issue in oncology. As a functional modality, nuclear medicine offers a variety of possibilities to assist in the clinical management of this disease. A brief survey of currently available techniques is presented for the diagnosis, staging and follow up, either by organ imaging or by using a great spectrum of tumour-seeking radiopharmaceuticals. The role of lymphoscintigraphy in melanoma is emphasized, as well as the supportive role of nuclear medicine in the surgical theater, enabling selective lymph node dissection by the sentinel node procedure and high dose regional chemotherapy by isolated limb perfusion. Although hardly used for metastatic melanoma so far, with all its tumour-seeking approaches nuclear medicine holds a therapeutic potential for this disease as well.     

Alternative lymphatic pathway after previous axillary node dissection in recurrent/primary breast cancer

OBJECTIVES: The sentinel lymph node approach has almost become the standard procedure of choice in the management of patients with early breast cancer. The status of sentinel nodes, whether or not pathologically involved by cancer cells, represents those of the axillary nodes with a negative predictive value of almost 100%. If the axillary lymphatic nodal drainage is altered, alternative lymphatic pathways and accordingly sentinel node location will be changed. METHODS: In this article, 4 patients are presented, 3 with recurrent breast cancer who had already undergone lumpectomy, axillary node dissection, and radiotherapy in the past and 1 with primary breast cancer after surgical removal of a malignant melanoma on her back and had axillary node dissection on the same side as the breast cancer. These patients underwent lymphoscintigraphy followed by sentinel node localization using the gamma probe and also blue dye injection during surgery. RESULTS: All patients showed alternate lymphatic pathways, 1 had an ipsilateral internal mammary node and crossed lymphatics to a contralateral axillary node, 2 had intramammary sentinel nodes, and 1 had an internal mammary on the same side. Pathologic examination of the intramammary and contralateral sentinel nodes were negative for metastases. Internal mammary sentinel nodes were not biopsied. CONCLUSION: We feel that sentinel node lymphoscintigraphy should be done even in patients who have altered lymphatic pathways resulting from previous axillary node dissection. It allows identifying and biopsy of the sentinel node at its new unpredicted location.     

Preliminary experiences with sentinel lymph node detection in cases of vulvar malignancy

Lymph node status is the most important prognostic factor in vulvar malignancy. The aim of this pilot study was to explore the clinical significance of radionuclide lymphoscintigraphy in the management of vulvar neoplasms. Eight patients with squamous cell carcinoma and two patients with malignant melanoma of the vulva were studied with 100 MBq technetium-99m nanocolloid (Sentiscint, OSSKI, Budapest) 1 day before surgery. The location of the sentinel lymph node was checked by a single-head gamma camera-computer system (MB 9200, Mediso, Budapest). Vulvectomy with bilateral inguinofemoral lymphadenectomy was performed in each case. At lymphadenectomy, the sentinel lymph node was separately removed and histologically studied. Three of the ten patients had positive sentinel lymph nodes (micrometastasis). Five months later one of them had local recurrence of the vulvar cancer, and another had inguinal recurrence of the tumour 6 months postoperatively; the third patient was operated on only recently. Our preliminary results are impressive and suggest that lymphoscintigraphy is an easy and reliable method for detection of the sentinel lymph node in vulvar malignancy.     

Use of intraoperative lymphoscintigraphy in doubtful cases of sentinel node detection

Lymphoscintigraphy is a widely accepted method used to detect selectively the sentinel node in malignant melanoma. This is the case report of a patient who was operated on for an inguinal melanoma and who was referred to the Nuclear Medicine Section for preoperative lymphoscintigraphy. There were technical problems for sentinel node detection due to the proximity of injection points. We aimed to know the possibility to perform an intraoperative lymphoscintigraphy as a valid and useful technique in cases as this one.     

Lymphoscintigraphy in cutaneous melanoma: a total body atlas of sentinel node mapping.

Lymphoscintigraphy of malignant melanoma has been a reliable method of identifying regional lymph nodes at risk for metastases and is now considered part of the standard of care in patients with melanoma. The status of the sentinel lymph node (SLN) is predictive of the metastatic status of the corresponding regional lymph node group. Lymphatic channel mapping allows identification of the SLN, thereby making selective lymph node sampling possible. Consequently, SLN identification with lymphoscintigraphy results in both less extensive surgery and more efficient pathologic examination of the lymph node specimens. Therefore, it is imperative that radiologists and nuclear medicine physicians know which radiopharmaceuticals to use, recognize different lymphatic drainage patterns from various primary tumor sites throughout the body, use proper imaging techniques, and recognize potential pitfalls in image interpretation.     

Nondetection of sentinel lymph node with lymphoscintigraphy as a result of massive malignant invasion shown by positron emission tomography.

PURPOSE: The authors report the complementary roles of lymphoscintigraphy in sentinel node mapping and F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in a massively invaded sentinel node. MATERIALS AND METHODS: A 49-year-old woman was referred to the authors' institution after the resection of a malignant melanoma (Clark IV, Breslow 5.25) of the right buttock. No evidence of regional or distant organ metastases was observed on bone scintigraphy or thoracoabdominal or cerebral computed tomographs. Preoperative lymphoscintigraphy showed drainage around a circular structure, without any node detected. F-18 FDG PET imaging detected an area of focal, markedly hypermetabolic activity at the same location. RESULTS: The focal, markedly hypermetabolic activity detected by F-18 FDG PET corresponded to a massively invaded sentinel node not shown by lymphoscintigraphy but found and removed at the time of surgery. Radical regional lymphadenectomy showed only one small additional lymph node micrometastasis detected after immunohistochemical staining for S-100 protein and HMB45 antigen. CONCLUSIONS: This case emphasizes the complementary roles of lymphoscintigraphy sentinel node mapping and F-18 FDG PET. Indeed, a massively invaded sentinel node may be detected by PET but missed by lymphoscintigraphy.     

Pearls and pitfalls of radionuclide imaging of the lymphatic system. Part 2: evaluation of extremity lymphoedema

This is the second of two pictorial essays on radionuclide imaging of the lymphatic system and will focus on evaluation of extremity lymphoedema using lymphoscintigraphy. Lymphoedema results from anatomical or functional obstruction of the lymphatic system. Lymphoscintigraphy is the imaging modality of choice for assessing lymphoedema. The technique plays a pivotal role in determining the aetiology of extremity swelling and helps guide treatment. The diagnostic utility of radionuclide imaging in lymphoedema depends upon careful technical performance and accurate image interpretation. We present a pictorial review emphasising the technical and interpretative pearls and pitfalls of radionuclide evaluation of lymphoedema.     

Extraordinary Lymph Drainage in Cutaneous Malignant Melanoma and the Value of Hybrid Imaging: A Case Report

In melanoma patients, preoperative lymphoscintigraphy has become a gold standard. The role of single-photon emission computed tomography (SPECT) or its combination with computed tomography (SPECT-CT) as part of the standard sentinel scintigraphy protocol has yet to be determined. A 46-year-old female patient with melanoma of the trunk received preoperative lymphoscintigraphy and subsequent surgical excision. Planar imaging displayed two hot spots in the region of the primary lesion. No other lymphatic flow pathways could be appreciated. Two focal hot spots, one dorsal to the primary lesion near the left latissimus dorsi muscle and one just lateral to the primary lesion in the subcutaneous tissue, were appreciated with SPECT-CT imaging. The primary melanoma lesion, as well as the two additional lesions, which were detected by SPECT-CT, were excised and sent for histopathological examination. While the primary lesion was a superficial spreading melanoma, the lesions appreciated in SPECT-CT revealed four sentinel lymph nodes, each of which was negative for tumor cells. Melanomas, especially of the trunk, can demonstrate multiple lymphatic drain basins in a large percentage of patients. Given that without the detailed anatomical information provided by SPECT-CT it would be very difficult to locate the diverse lymphatic drain basins and their lymph nodes, we would suggest routinely implementing SPECT-CT in the standard planar sentinel imaging protocol.     

Radioguided sentinel lymph node biopsy in malignant cutaneous melanoma.

The procedure of sentinel lymph node biopsy in patients with malignant cutaneous melanoma has evolved from the notion that the tumor drains in a logical way through the lymphatic system, from the first to subsequent levels. As a consequence, the first lymph node encountered (the sentinel node) will most likely be the first affected by metastasis; therefore, a negative sentinel node makes it highly unlikely that other nodes in the same lymphatic basin are affected. Although the long-term therapeutic benefit of the sentinel lymph node biopsy per se has not yet been ascertained, this procedure distinguishes patients without nodal metastases, who can avoid nodal basin dissection with its associated risk of lymphedema, from those with metastatic involvement, who may benefit from additional therapy. Sentinel lymph node biopsy would represent a significant advantage as a minimally invasive procedure, considering that an average of only 20% of melanoma patients with a Breslow thickness between 1.5 and 4 mm harbor metastasis in their sentinel node and are therefore candidates for elective lymph node dissection. Furthermore, histologic sampling errors (amounting to approximately 12% of lymph nodes in the conventional routine) can be reduced if one assesses a single (sentinel) node extensively rather than assessing the standard few histologic sections in a high number of lymph nodes per patient. The cells from which cutaneous melanomas originate are located between the dermis and the epidermis, a zone that drains to the inner lymphatic network in the reticular dermis and, in turn, to larger collecting lymphatics in the subcutis. Therefore, the optimal route for interstitial administration of radiocolloids for lymphoscintigraphy and subsequent radioguided sentinel lymph node biopsy is intradermal or 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 along the midline 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 nodes. The sentinel lymph node should have a significantly higher count than that of the 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. Virtually the entire sentinel lymph node should be processed for histopathology, including both conventional hematoxylin-eosin staining and immune staining with antibodies to the S-100 and HMB-45 antigens. The success rate of radioguidance in localizing the sentinel lymph node in melanoma patients is approximately 98% in institutions that perform a high number of procedures and approaches 99% when combined with the vital blue-dye technique. Growing evidence of the high correlation between a sentinel lymph node biopsy negative for cancer and a negative status for the lymphatic basin-evidence, therefore, of the high prognostic value of sentinel node biopsy-has led to the procedure's being included in the most recent version of the TNM staging system and starting to become the standard of care for patients with cutaneous melanoma.     

Evaluation and localization of lymphatic drainage and sentinel lymph nodes in patients with head and neck melanomas by hybrid SPECT/CT lymphoscintigraphic imaging

In patients with head and neck tumors, preoperative lymphoscintigraphy can be used to map lymphatic drainage patterns and identify sentinel lymph nodes. However, it is very difficult to determine the exact locations of head and neck sentinel nodes on preoperative lymphoscintigraphy without the use of anatomic landmarks. Lymph nodes in the head and neck are grouped into 7 regions, or levels, on the basis of anatomic landmarks. In patients undergoing standard lymphoscintigraphy, obtaining lateral marker images that show important anatomic landmarks can help with the localization of sentinel nodes. However, technical problems often render marker images of little or no use. Hybrid SPECT/CT lymphoscintigraphic imaging facilitates the localization of sentinel nodes by reliably showing the relationships between sentinel nodes and important anatomic structures. After reading this article, the reader should understand the lymph node level classification system for head and neck melanomas, be able to describe the technique used for the imaging of sentinel nodes in the head and neck region, and be able to demonstrate how SPECT/CT lymphoscintigraphic imaging can enable precise sentinel node localization and thus help to ensure minimal dissection.     

Patterns of lymphatic drainage from the skin in patients with melanoma.

An essential prerequisite for a successful sentinel lymph node biopsy (SLNB) procedure is an accurate map of the pattern of lymphatic drainage from the primary tumor site in each patient. In melanoma patients, mapping requires high-quality lymphoscintigraphy, which can identify the actual lymphatic collecting vessels as they drain into the sentinel lymph nodes. Small-particle radiocolloids are needed to achieve this goal, and imaging protocols must be adapted to ensure that all true sentinel nodes, including those in unexpected locations, are found in every patient. Clinical prediction of lymphatic drainage from the skin is not possible. The old clinical guidelines based on Sappey's lines therefore should be abandoned. Patterns of lymphatic drainage from the skin are highly variable from patient to patient, even from the same area of the skin. Unexpected lymphatic drainage from the skin of the back to sentinel nodes in the triangular intermuscular space and, in some patients, through the posterior body wall to sentinel nodes in the para-aortic, paravertebral, and retroperitoneal areas has been found. Lymphatic drainage from the head and neck frequently involves sentinel nodes in multiple node fields and can occur from the base of the neck up to nodes in the occipital or upper cervical areas or from the scalp down to nodes at the neck base, bypassing many node groups. The sentinel node 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." Lymphatic drainage can occur from the upper limb to sentinel nodes above the axilla. Drainage to the epitrochlear region from the hand and arm as well as to the popliteal region from the foot and leg is more common than was previously thought. Interval nodes, which lie along the course of a lymphatic vessel between a lesion site and a recognized node field, are not uncommon, especially in the trunk. Drainage across the midline of the body is quite common in the trunk and in the head and neck. Micrometastatic disease can be present in any sentinel node regardless of its location, and for the SLNB technique to be accurate, all true sentinel nodes must be biopsied in every patient.     

Identification of bilateral breast sentinel lymph nodes draining primary melanoma of the back by preoperative lymphoscintigraphy and intraoperative mapping.

A 30-year-old white woman with a primary malignant melanoma of her right back at the Sappey line, 4 cm from the midline at the L2 level, underwent preoperative lymphoscintigraphy and intraoperative mapping of the sentinel lymph node using lymphazurin injection at the primary site and a hand-held gamma probe. Lymphoscintigraphy showed one sentinel lymph node in each breast and another one in the right axilla. These three sentinel lymph nodes were accurately identified using a hand-held gamma probe during operation. An additional sentinel and one nonsentinel lymph node from the right axilla were harvested. All four sentinel lymph nodes were blue and showed significantly elevated radioactivity compared with background. Histologic analysis showed that all these lymph nodes were negative for metastatic melanoma. She has been followed for a period of 26.7 months since her selective sentinel lymphadenectomy and has been free of disease to date. This case illustrates the importance of preoperative lymphoscintigraphy in identifying in-transit sentinel lymph nodes in both breasts in addition to the clinically predictable sentinel lymph node(s) in the right axilla.     

Revolutionary impact of lymphoscintigraphy and intraoperative sentinel node mapping in the clinical practice of oncology

Intraoperative lymphatic mapping is a rapidly emerging diagnostic approach that is revolutionizing the management of patients who have solid malignant tumors. The procedure is being performed for the most part with radiopharmaceuticals and vital blue dyes. It is widely believed that passive trapping of radioactive particles determines the sentinel lymph node (SLN) for intraoperative delineation of potential draining sites. In this article, we show that dendritic cells within the SLN actively take up and trap radioactive particles and thus define the SLN immunologically. The role of preoperative lymphoscintigraphy and the selection of the site of placement of mapping reagents for intraoperative lymphatic mapping are established for patients with melanoma. For patients with breast cancer, the role of preoperative lymphoscintigraphy is controversial. We have shown that this procedure can be performed with success in identifying SLN as hot spots 87% of the time, with 20% of the cases showing draining nodes to other basins in addition to or independent of the axilla. The use of preoperative lymphoscintigraphy for patients with breast cancer can therefore be justified. The selection of the site for placement of radiotracer and blue dye can vary for patients with breast cancer depending on the primary site of the lesion. However, based on data from our institution and others, the delivery of the mapping reagents (both radioactive tracers and blue dye) to the subareolar space may help to standardize breast cancer SLN mapping.     

Sentinel node detection in pre-operative axillary staging

The concept of sentinel lymph node biopsy in breast cancer surgery is based on the fact that the tumour drains in a logical way via the lymphatic system, from the first to upper levels. Since axillary node dissection does not improve the prognosis of patients with breast cancer, sentinel lymph node biopsy might replace complete axillary dissection for staging of the axilla in clinically N0 patients. Sentinel lymph node biopsy would represent a significant advantage as a minimally invasive procedure, considering that about 70% of patients are found to be free from metastatic disease, yet axillary node dissection can lead to significant morbidity. Subdermal or peritumoural injection of small aliquots (and very low activity) of radiotracer is preferred to intratumoural administration, and (99m)Tc-labelled colloids with most of the particles in the 100-200 nm size range would be ideal for radioguided sentinel node biopsy in breast cancer. The success rate of radioguidance in localising the sentinel lymph node in breast cancer surgery is about 97% in institutions where a high number of procedures are performed, and the success rate of lymphoscintigraphy in sentinel node detection is about 100%. The sentinel lymph node should be processed for intraoperative frozen section examination in its entirety, based on conventional histopathology and, when necessary, immune staining with anti-cytokeratin antibody. Nowadays, lymphoscintigraphy is a useful procedure in patients with different clinical evidence of breast cancer.     

Correlation between theoretical anatomical patterns of lymphatic drainage and lymphoscintigraphy findings during sentinel node detection in head and neck melanomas

Purpose

In the diagnosis of head and neck melanoma, lymphatic drainage is complex and highly variable. As regional lymph node metastasis is one of the most important prognostic factors, lymphoscintigraphy can help map individual drainage patterns. The aim of this study was to compare the results of lymphoscintigraphy and sentinel lymph node (SLN) detection with theoretical anatomical patterns of lymphatic drainage based on the location of the primary tumour lesion in patients with head and neck melanoma. We also determined the percentage of discrepancies between our lymphoscintigraphy and the theoretical location of nodal drainage predicted by a large lymphoscintigraphic database, in order to explain recurrence and false-negative SLN biopsies.

Methods

In this retrospective study of 152 patients with head and neck melanoma, the locations of the SLNs on lymphoscintigraphy and detected intraoperatively were compared with the lymphatic drainage predicted by on-line software based on a large melanoma database.

Results

All patients showed lymphatic drainage and in all patients at least one SLN was identified by lymphoscintigraphy. Of the 152 patients, 4 had a primary lesion in areas that were not described in the Sydney Melanoma Unit database, so agreement could only be evaluated in 148 patients. Agreement between lymphoscintigraphic findings and the theoretical lymphatic drainage predicted by the software was completely concordant in 119 of the 148 patients (80.4 %, 95 % CI 73.3 – 86 %). However, this concordance was partial (some concordant nodes and others not) in 18 patients (12.2 %, 95 % CI 7.8 – 18.4 %). Discordance was complete in 11 patients (7.4 %, 95 % CI 4.2 – 12.8 %).

Conclusion

In melanoma of the head and neck there is a high correlation between lymphatic drainage found by lymphoscintigraphy and the predicted drainage pattern and basins provided by a large reference database. Due to unpredictable drainage, preoperative lymphoscintigraphy is essential to accurately detect the SLNs in head and neck melanoma.

     

Vital dyes in sentinel node localization

Vital blue dyes were used to show the feasibility and accuracy of intraoperative lymphatic mapping of the sentinel node (SN) in patients with melanoma, breast cancer, and other solid tumors. Surgeons who have successfully completed an adequate number of cases of intraoperative mapping and sentinel lymph node dissection (SLND) can use blue dye alone to localize the SN. However, radiopharmaceutical agents can facilitate intraoperative mapping; preoperative lymphoscintigraphy can identify the location of the SN, and intraoperative mapping with the gamma probe can provide an auditory signal that complements the visual guide provided by the blue dye. Studies are required to establish more clearly the intralymphatic kinetics of the various radiopharmaceutical agents. An ongoing international Phase III trial in melanoma, the 2 upcoming trials in breast cancer, and similar trials for other solid tumors will further clarify the future role of SLND.     

Intra-individual comparison of sentinel lymph node scintigraphy on the day of injection and on the following day in breast cancer

OBJECTIVES: To compare, intra-individually, the detection rates of sentinel node on lymphoscintigraphy performed on the day of injection (D0) and on the following day (D1) in breast carcinoma. We also compared 2-day and 1-day protocols in the two groups of patients. METHODS: The 2-day and 1-day protocols included 76 patients in group 1 and 23 patients in group 2. Patients from group 1 underwent lymphoscintigraphy twice--at 2 h (lymphoscintigraphy 1) and 18 h (lymphoscintigraphy 2) post-injection at four sites periareolar using 99mTc sulfur colloid. Patients from group 2 underwent lymphoscintigraphy only at 2 h post-injection. The detection rates and the number of sentinel nodes were compared in the two lymphoscintigraphy examinations for group 2. RESULTS: The detection rate on lymphoscintigraphy in group 1 was 92% at D0 and 96% at D1. The overall agreement between lymphoscintigraphy 1 and lymphoscintigraphy 2 was 69/76 (91%). In 2/76 women, the sentinel node disappeared at D1 on lymphoscintigraphy, but remained detectable during surgery, and in 5/76 women, the sentinel node appeared at D1 on lymphoscintigraphy. The mean number of sentinel nodes detected on lymphoscintigraphy was 2.05+/-0.14 at D0 and 1.76+/-0.11 at D1 (P=0.004) in group 2, the detection rate of the sentinel node was 20/23 (87%). CONCLUSION: Our study demonstrated that for patients undergoing the 2-day protocol for sentinel node procedure in early stage breast cancer, the optimal imaging time would be to perform lymphoscintigraphy 1 h after injection, with the possibility of imaging patients the following day in cases where lymphoscintigraphy was negative.