Vital dyes in sentinel node localization

The Use and Technique of Sentinel Node Biopsy for Skin Cancer

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the indications for and prognostic value of sentinel lymph node biopsy in skin cancer. 2. Learn the advantages and disadvantages of various modalities used alone or in combination when performing sentinel lymph node biopsy. 3. Understand how to perform sentinel lymph node biopsy in skin cancer patients.

SUMMARY

Advances in technique used to perform sentinel lymph node biopsy to assess lymph node status have led to increased accuracy of the procedure and improved patient outcomes.

Percutaneous contrast-enhanced ultrasound for localization and diagnosis of sentinel lymph node in early breast cancer

This study assessed the efficacy of percutaneous contrast-enhanced ultrasound (CEUS) in localization sentinel lymph node (SLNs) for biopsy and diagnosis of metastatic SLNs in patients with early breast cancer. From January to November 2017, seventy-five patients with early breast cancer confirmed by pathology were enrolled in this study. CEUS was performed after subdermal injection of ultrasound contrast agent (SonoVue, 2.0 ml in total dose) around the areola on the ipsilateral side of the breast. The contrast-enhanced lymphatic vessels and associated SLNs were observed and traced in real time. The lymphatic vessels and SLN were mapped and labeled on the skin surface. Sentinel lymph node biopsy (SLNB) was performed after injection of 2.0 ml methylene blue at same injection site of SonoVue. The accuracy of percutaneous CEUS localization of SLNs was determined compared to blue dye injection technique. The pathological results under blue dye guided biopsy were used as the reference standard to calculate the sensitivity and specificity of CEUS for the diagnosis of SLNs. A total of 163 SLNs obtained through SLNB following methylene blue tracing in 75 patients. There were 116 SLNs identified by percutaneous CEUS. The difference of detection rates between blue dye and CEUS was statistically significant (Z = -2.651, P = 0.008). The identification rate of SLNs by CEUS was 71.17% (116/163). The accuracy of percutaneous CEUS localization of axillary SLNs was 94.67% (71/75) compared to blue dye-guided biopsy. Among the 116 SLNs detected by percutaneous CEUS, pathologic results showed 51 positive SLNs and 65 negative SLNs whiles CEUS findings indicated 83 positive SLNs and 33 negative SLNs. Only 50 of 83 SLNs had metastasis on pathology, while 33 were detected as false positive. The sensitivity and specificity of CEUS for the diagnosis of metastatic SLN was 98.04%(50/51) and 49.23%(32/65), respectively. Percutaneous CEUS can be used as an effective method to localize the SLNs for guiding SLNB. This method has excellent sensitivity for identifying the SLNs but lower specificity for detecting metastatic SLNs in patients with early stage breast cancer.

Subdermal Ultrasound Contrast Agent Injection for Sentinel Lymph Node Identification: An Analysis of Safety and Contrast Agent Dose in Healthy Volunteers

OBJECTIVES

Mapping of the lymphatic chain for identification of the sentinel lymph node (SLN) is an important aspect of predicting outcomes for patients with breast cancer, and it is usually performed as an intraoperative procedure using blue dye and/or radiopharmaceutical agents. Recently, the use of contrast-enhanced ultrasound (CEUS) has been proposed as an alternative imaging technique for this mapping. The objective of this study was to evaluate the use of subdermal administration of the ultrasound (US) contrast agent Sonazoid (GE Healthcare, Oslo, Norway) in terms of patient safety and to select the dose to be used for lymphatic applications in humans.

METHODS

This study was performed in 12 female volunteers who received bilateral subdermal injections of Sonazoid (1 or 2 mL dose) in the mid-upper outer quadrant of their breasts at 2 different time points. Contrast-enhanced US examinations were performed 0, 0.25, 0.5, 1, 2, 4, 6, and 24 hours after injection to identify SLNs.

RESULTS

Sentinel lymph nodes were identified within the first hour after injection as enhanced structures, and there was no significant difference by dose in the number of SLNs identified (P = .74). The volunteers only had minor adverse experiences (AEs) that resolved completely without intervention by study completion.

CONCLUSIONS

The subdermal use of Sonazoid in this study showed only minor local and nonsignificant AEs that were completely resolved without any intervention. Two different doses were compared with no significant differences observed between them. Hence, the lower dose studied (1 mL) was selected for use in future clinical studies.

Indocyanine-green-loaded microbubbles for localization of sentinel lymph node using near-infrared fluorescence/ultrasound imaging: a feasibility study

Current strategies for sentinel lymph node (SLN) biopsy to detect cancer metastasis have some limitations such as the associated radiation exposure and high false-negative rates due to dye particles through the true SLNs to contiguous LNs.

A prospective pilot study of detection of sentinel lymph nodes in gynaecological cancers using a novel near infrared fluorescence imaging system

BACKGROUND

Sentinel Lymph Node (SLN) sampling may significantly reduce surgical morbidity by avoiding needless radical lymphadenectomy. In gynaecological cancers, the current practice in the UK is testing the accuracy of SLN detection using radioactive isotopes within the context of clinical trials. However, radioactive tracers pose significant logistic problems. We, therefore, conducted a pilot, observational study to assess the feasibility of a novel optical imaging device for SLN detection in gynaecological cancers using near infrared (NIR) fluorescence.

METHODS

A novel, custom-made, optical imaging system was developed to enable detection of multiple fluorescence dyes and allow simultaneous bright-field imaging during open surgery and laparoscopic procedures. We then evaluated the performance of the system in a prospective study of 49 women with early stage vulval, cervical and endometrial cancer who were scheduled to undergo complete lymphadenectomy. Clinically approved fluorescent contrast agents indocyanine green (ICG) and methylene blue (MB) were used. The main outcomes of the study included SLN mapping detection rates, false negative rates using the NIR fluorescence technique and safety of the procedures. We also examined the association between injection sites and differential lymphatic drainage in women with endometrial cancer by fluorescence imaging of ICG and MB.

RESULTS

A total of 64 SLNs were detected during both open surgery and laparoscopy. Following dose optimisation and the learning phase, SLN detection rate approached 100 % for all cancer types with no false negatives detected. Fluorescence from ICG and MB detected para-aortic SLNs in women with endometrial cancer following uterine injection. Percutaneous SLN detection was also achieved in most women with vulval cancer. No adverse reactions associated with the use of either dyes were observed.

CONCLUSIONS

This study demonstrated the successful clinical application of a novel NIR fluorescence imaging system for SLN detection across different gynaecological cancers. We showcased the first in human imaging, during the same procedure, of two fluorescence dyes in women with endometrial cancer.

Contrast-enhanced sonography for detection of secondary lymph nodes in a melanoma tumor animal model

OBJECTIVES

To investigate the use of contrast-enhanced ultrasound imaging (US) for detection of secondary lymph nodes (LNs) in a naturally occurring melanoma swine model compared to surgery and pathologic assessment.

METHODS

Twenty-seven Sinclair swine were studied. The perfluorobutane microbubble contrast agent Sonazoid (GE Healthcare, Oslo, Norway) was administered (1.0 mL total dose) around the melanoma, and contrast-enhanced US was used to localize contrast-enhanced sentinel lymph nodes (SLNs). Then Sonazoid (dose, 0.25-1.0 mL) was injected into the SLNs to detect contrast-enhanced efferent lymphatic channels and secondary LNs. After peritumoral injection of blue dye, a surgeon (blinded to the contrast-enhanced US results) performed a radical LN dissection. Contrast-enhanced US was used to guide removal of any enhanced secondary LNs left after radical LN dissection. Clustered conditional logistic regression analyzed the benefit of contrast-enhanced US-directed secondary LN dissection over radical LN dissection using pathologic findings as the reference standard.

RESULTS

A total of 268 secondary LNs were resected, with 59 (22%) containing metastases. Contrast-enhanced US detected 92 secondary LNs; 248 were identified by radical LN dissection; and 68 were identified by both methods. Metastases were detected in 20% (51 of 248) and 40% (37 of 92) of the secondary LNs identified by radical LN dissection and contrast-enhanced US, respectively. Thus, secondary LNs detected by contrast-enhanced US were nearly 5 times more likely to contain metastases than secondary LNs removed by radical LN dissection (odds ratio, 4.8; P < .0001). Twenty-two of the 180 secondary LNs (12%) identified only by radical LN dissection contained metastases, whereas contrast-enhanced US identified 20 secondary LNs after the surgeon completed the radical LN dissection, of which 8 (40%) contained metastases.

CONCLUSIONS

Secondary LNs can be detected by using contrast-enhanced US after injection of Sonazoid into SLNs. Secondary LNs detected with contrast-enhanced US are significantly more likely to contain metastases than those removed by radical LN dissection.

Detection and credibility of sentinel node in vulvar cancer: a single institutional study and short review of literature

PURPOSE

To evaluate the detectability and credibility of sentinel lymph node (SLN) in vulvar cancer.

METHODS

With Tc99m-nanocolloid and methylene blue, we identified SLNs in 34 patients. In 27 cases both tracers were used, while in 7 only blue dye was used. Completion lymphadenectomy was performed in all patients. SLNs and non-SLNs were sent separately for pathologic evaluation.

RESULTS

At least one SLN was identified in all patients. Detection rate per groin was not significantly higher in the combined versus blue dye only technique (42/50 vs. 10/14, p = 0.43). 99m-Tc was not superior to blue dye in detecting SLN (42/50 vs. 50/64, p = 0.65). Midline location of the tumor did not seem to negatively affect the procedure. Four false negatives were observed in three patients with tumors >4 cm. Negative predictive value of SLN was 100% for grade I tumors ≤ 4 cm in patients ≤ 71 years.

CONCLUSION

Tc-99m does not seem to be superior to methylene blue in the detection of SLN in vulvar cancer. Patients of younger age with small, well-differentiated tumors appear to be the most suitable candidates for lymphatic mapping.

Contrast-enhanced ultrasound imaging of sentinel lymph nodes after peritumoral administration of Sonazoid in a melanoma tumor animal model

OBJECTIVES

The purpose of this study was to compare lymphosonography (ie, contrast-enhanced ultrasound imaging [US] after interstitial injection of a US contrast agent) for the detection of sentinel lymph nodes (SLNs) in swine with naturally occurring melanoma tumors to lymphoscintigraphy using blue dye-guided surgical dissection as the reference standard. Also, we sought to determine if lymphosonography can be used to characterize SLNs.

METHODS

Sixty-three swine with 104 melanomas were evaluated. Contrast-specific US was performed after peritumoral injection (1 mL dose) of Sonazoid (GE Healthcare, Oslo, Norway). Lymphoscintigraphy was performed after peritumoral injections of technetium Tc 99m sulfur colloid. Peritumoral injection of 1% Lymphazurin (Ben Venue Labs, Inc, Bedford, OH) was used to guide SLN resection. The accuracy of SLN detection with the two imaging modalities was compared using the McNemar test. The SLNs were qualitatively and quantitatively characterized as benign or malignant based on the lymphosonography results with histopathology and RNA analyses used as the reference standards.

RESULTS

Blue dye-guided surgery identified 351 SLNs. Lymphosonography detected 293 SLNs and 11 false-positives, while lymphoscintigraphy detected 231 SLNs and 20 false-positives. The accuracy of SLN detection was 81.8% for lymphosonography, which was significantly higher than the 63.2% achieved with lymphoscintigraphy (P < .0001). The accuracy of lymphosonography for SLN characterization was 80%. When the size of the enhanced SLN was taken into consideration to characterize SLNs, the accuracy was 86%.

CONCLUSIONS

Lymphosonography is statistically better than lymphoscintigraphy for the detection of SLNs in this animal model. The ability to use lymphosonography as a means to characterize SLNs as benign or malignant is limited.

Comparison of efficacy of Tc-99m HIG and Tc-99m nanocolloid on sentinel lymph node mapping in patients with breast cancer

BACKGROUND AND AIM

This study compared the effectiveness of Tc-99m human polyclonal immunoglobulin (HIG) and Tc-99m nanocolloid at detecting sentinel lymph nodes (SLNs) with lymphoscintigraphy and an intraoperative gamma-probe (IGP) in patients with early breast cancer.

METHODS

The study group consisted of 50 women; 25 patients each were given Tc-99m HIG or Tc-99m nanocolloid for lymphoscintigraphy. Then, intraoperative SLN localization with IGP was performed. The results of IGP, lymphoscintigraphy, blue dye injected just before surgery, and pathology were compared.

RESULTS

In the Tc-99m HIG group, one patient had tumours in both breasts. In two patients, we could not detect SLNs with lymphoscintigraphy, although they were detected with IGP and blue dye. We found SLNs for all tumours with IGP. With the intraoperative blue dye, SLNs were identified for 25 tumours; for one tumour, no SLN was detected with blue dye. In the histopathological examination, 13 tumours showed metastasis in the SLN and in 11 of these 13, there were also metastases in the axilla. One patient had a skip metastasis. In the Tc-99m nanocolloid group, SLNs were identified in 24 patients with lymphoscintigraphy. IGP found SLNs in 24 patients. The blue dye detected SLNs in all patients. On histopathological examination, 10 patients had metastasis in the SLN and there were also metastases in the axilla in all of these patients.

CONCLUSION

Tc-99m HIG can be used in SLN detection with preoperative lymphoscintigraphy and IGP in early-stage breast cancer patients.

Gray-scale contrast-enhanced ultrasonography of sentinel lymph nodes in a metastatic breast cancer model

RATIONALE AND OBJECTIVES

Previous studies showed it was possible to employ sonographic contrast agent for identification of the sentinel lymph nodes (SLNs). This study is to investigate the usefulness of SonoVue (a sonographic contrast agent) and gray-scale contrast-enhanced ultrasonography (CEUS) for detecting the SLNs in a metastatic breast cancer model.

MATERIALS AND METHODS

CEUS was performed in 12 female rabbits with breast VX2 tumor after subcutaneous administration of SonoVue. The site, number, and pattern of enhancement of the SLNs were observed and recorded. After CEUS, 0.5 mL of blue dye was injected into the same location as SonoVue and the SLNs were detected by surgical dissection. The findings of CEUS were compared with those of blue dye.

RESULTS

Of the 12 tumors assessed, a total of 17 enhanced SLNs were detected by CEUS. Among them, a single SLN was detected in eight tumors, two SLNs in three tumors, and three SLNs in one tumor. All the SLNs showed partial enhancement on CEUS. Nineteen SLNs were identified by blue dye with surgical dissection. There were no false-positive CEUS findings in terms of SLN detection. The overall sensitivity of CEUS for detecting SLNs was 89.5% (17/19). Among the 17 SLNs detected by CEUS, tumor metastases were identified histopathologically in 4 SLNs, whereas proliferation of lymphatic tissue was identified in the other 13 SLNs.

CONCLUSIONS

CEUS combined with SonoVue is useful for detecting SLNs, although it may not be helpful for detecting metastases in SLNs.

Gray-scale contrast-enhanced ultrasonography in detecting sentinel lymph nodes: an animal study

OBJECTIVE

To investigate the usefulness of gray-scale contrast-enhanced ultrasonography for detecting sentinel lymph nodes.

METHODS

Contrast-enhanced ultrasonography was performed in five normal dogs (four female and one male) after subcutaneous administration of a sonographic contrast agent (Sonovue, Bracco, Milan, Italy). Four distinct regions in each animal were examined. After contrast-enhanced ultrasonography, 0.8 ml of blue dye was injected into the same location as Sonovue and the sentinel lymph nodes were detected by surgical dissection. The findings of contrast-enhanced ultrasonography were compared with those of the blue dye.

RESULTS

Twenty-one sentinel lymph nodes were detected by contrast-enhanced ultrasonography while 23 were identified by blue dye with surgical dissection. Compared with the blue dye, the detection rate of enhanced ultrasonography for the sentinel lymph nodes is 91.3% (21/23). Two patterns of enhancement in the sentinel lymph nodes were observed: complete enhancement (5 sentinel lymph nodes) and partial enhancement (16 sentinel lymph nodes). The lymphatic channels were demonstrated as hyperechoic linear structures leading from the injection site and could be readily followed to their sentinel lymph nodes. Histopathologic examination showed proliferation of lymphatic follicles or lymphatic sinus in partial enhanced sentinel lymph nodes while normal lymphatic tissue was demonstrated in completely enhanced sentinel lymph nodes.

CONCLUSIONS

Sonovue combined with gray-scale contrast-enhanced ultrasonography may provide a feasible method for detecting sentinel lymph nodes.

Validation and application of the sentinel lymph node concept in malignant vulvar tumours

PURPOSE

Inguinal lymphadenectomy, unilateral or bilateral, is widely used in cases of vulvar squamous cell carcinoma and melanoma but has a high morbidity. Sentinel lymph node (SLN) biopsy may be used in the management of these patients. The aims of this study were firstly to determine the reliability of SLN biopsy in predicting regional lymph node status and secondly to apply this technique in the routine clinical setting.

METHODS

We prospectively studied 70 women with vulvar malignancies. The first 50 cases were of squamous vulvar cancer and were used to validate the SLN technique in this clinical setting (validation group). Once a satisfactory success rate had been achieved in the validation group, the SLN technique was applied to a further 20 patients with vulvar malignancies, i.e. squamous cell carcinoma (n=12) and melanomas (n=8) (application group). Dynamic and static images were acquired after the injection of 74-148 MBq of a colloidal albumin, and continued until SLN identification. Fifteen minutes before surgery, blue dye injection was administered in a similar manner to the radiocolloid. After incision, a hand-held gamma probe was used to find the SLN. In the validation group, dissection of the SLN was always followed by lymphadenectomy. In the application group, this procedure was only performed if the SLN was positive for metastases. For pathological staging, samples were evaluated using haematoxylin and eosin and immunohistochemistry.

RESULTS

In the validation group, lymphoscintigraphy allowed SLN detection in 49/50 patients (98%). Blue dye detected the SLN in 40/50 patients (80%). In 16 patients (33%), the SLN showed metastases in the pathology study. All 33 patients with negative SLN had regional lymph nodes negative for metastases (negative predictive value 100%). In the application group, lymphoscintigraphy showed drainage to an SLN in 19 out of 20 patients (95%) and blue dye demonstrated a stained SLN in 17/20 patients (85%). Seven of the 19 SLN-identified nodes (37%) were positive for metastases.

CONCLUSION

SLN identification permits the accurate pathological study of regional nodes and could reduce the high morbidity of current surgical treatment in vulvar tumour patients if the technique were to be adopted on a routine clinical basis.

Contrast-assisted ultrasound for sentinel lymph node detection in spontaneously arising canine head and neck tumors

OBJECTIVES

We sought to evaluate a minimally invasive contrast-assisted ultrasound (US) technique for sentinel lymph node (SLN) localization.

METHODS

Microbubble contrast medium was injected into peritumoral tissues in 10 dogs with spontaneous head or neck tumors. Regional lymph nodes (LNs) were imaged up to 20 minutes after contrast administration using power Doppler US. Comparative lymphoscintigraphy studies were performed in all dogs by peritumoral injection of 99mTc-sulfur colloid administered around the primary lesion.

RESULTS

US contrast enhancement of SLN revealed sentinel nodes and associated lymphatics in 8 of 10 dogs. In each instance in which contrast-enhanced LN was identified with US, a corresponding SLN was detected by lymphoscintigraphy. Multiple SLNs were present in 2 dogs. Regional lymph nodes were positive for metastasis in 1 dog and reactive in 9 dogs.

CONCLUSIONS

Contrast-assisted US is effective in localizing SLN. This technique could reduce or eliminate many of the limitations of current SLN detection procedures.

The efficacy of 99mTc-HIG for sentinel lymph node mapping in breast cancer patients

OBJECTIVE

To evaluate the efficacy of Tc-HIG on SLN identification in patients with early-stage breast cancer.

MATERIALS AND METHODS

Seventeen women (18 tumours) with early-stage breast cancer were included. On the day of the operation, 111 MBq Tc-HIG was injected around the tumour or biopsy scar in all patients. Subsequently, dynamic lymphoscintigraphic images were taken for 30 min. After this, static images were recorded at 15-20 min intervals until the SLN was visualized. Patients were taken to the operating room 2-4 h after radiopharmaceutical injection. Before the incision, 5 ml of isosulfan blue dye solution was injected peritumourally in all subjects. Aided by blue dye and gamma probe SLN detection was done during the operation.

RESULTS

In 17/18 tumours, SLN was detected with Tc-HIG lymphoscintigraphy. The mean visualization time for axillary SLNs was 49.94+/-11.25 min and for internal mammary SLNs was 52.50+/-10.60 min. In 15 of the tumours, only one SLN was detected in the axillary region. However, in two tumours, SLNs were found in both axillary and internal mammary regions. With blue dye mapping, axillary SLNs were found in 17/18 tumours. With the application of intraoperative gamma probe, all axillary and internal mammary SLNs were detected in 18 tumours.

CONCLUSION

We conclude that Tc-HIG may be a suitable agent for SLN detection by lymphoscintigraphy and intraoperative gamma probe application in early-stage breast cancer patients.

Contrast-enhanced sonographic imaging of lymphatic channels and sentinel lymph nodes

OBJECTIVE

The purpose of this study was to determine whether lymphatic channels (LCs) and sentinel lymph nodes (SLNs) could be detected on sonographic imaging after subcutaneous, submucosal, or parenchymal injections of a sonographic contrast agent (ie, lymphosonography) in a variety of anatomic locations in several animal models.

METHODS

Eight swine, 7 canines, 4 rabbits, and a monkey were used for these evaluations. Gray scale pulse inversion harmonic imaging of the LCs and the SLNs was performed after subcutaneous (n = 58), submucosal (n = 14), or parenchymal (n = 8) injections of a tissue-specific sonographic contrast agent (Sonazoid; GE Healthcare, Oslo, Norway). In many instances, blue dye was injected into the same locations as Sonazoid, and surgical dissection of the SLNs and LCs was performed for comparison. Scanning electron microscopy (SEM) of contrast-enhanced and control lymph nodes from 2 rabbits was performed to determine the mechanism of contrast agent uptake and retention within SLNs.

RESULTS

After subcutaneous, submucosal, or parenchymal contrast agent injections, gray scale pulse inversion harmonic imaging could be used to identify the number and location(s) of LCs and SLNs. After subcutaneous, submucosal, or parenchymal contrast agent injections, Sonazoid was confined to the SLNs (ie, contrast enhancement was not detected in the second-echelon nodes). There was good agreement between the results of lymphosonography and blue dye with surgical dissection in identifying the regional LCs and SLNs. Scanning electron microscopy identified vacuoles representing intact contrast microbubbles within contrast-enhanced SLN macrophages, which were not present in the control lymph nodes.

CONCLUSIONS

Lymphosonography can be used to detect lymphatic drainage pathways and SLNs in a variety of animal models.

Sentinel node biopsy procedures with an analysis of recurrence patterns and prognosis in melanoma patients: technical advantages using computer-assisted gamma probe with adjustable collimation

The purpose of this study was to investigate whether a computer-assisted gamma probe with adjustable collimation could aid in the detection of sentinel nodes (SNs) and to analyse the patterns of recurrence and prognosis in SN-positive and SN-negative cases. We analysed 385 SN biopsies. The SN identification rate was 87.2% using preoperative lymphoscintigraphy and blue dye, 93.9% using preoperative lymphoscintigraphy, blue dye and different probes, and 100% using preoperative lymphoscintigraphy, blue dye and a computer-assisted probe with adjustable collimation. The computer-assisted probe was particularly advantageous in cases where the melanoma was located very close to the SN and in cases of deep-seated nodes or nodes with low uptake, due to the possibility of changing the collimation during the procedure. The SN-positive rate according to the thickness of the primary melanoma was 1.7% for melanomas < or = 1 mm in thickness and 27.5% for melanomas > or = 1 mm. In 4.9% of cases we identified nodes outside the regional nodal basin. In one case we found a micrometastasis in a blue and hot interval node of the lateral abdominal wall. Analysing the node counts registered by the computer-assisted probe, we verified that the blue-positive node for tumour metastases was not the most radioactive node in the field in six out of 52 positive cases (11.5%). Distant metastases were present in 2.0% of SN-negative patients, and in 24% of SN-positive patients (P < 0.001). Highly statistically significant differences were found between SN-negative and SN-positive patients in both the 3 year disease-free survival (86.3% versus 49.2%) and the 3 year disease-specific survival (92.3% versus 77.1%) (P < 0.001).

J, Lewin S, Marone MMS. Pesquisa do linfonodo sentinela em pacientes com melanoma: experiência com fitato marcado com Tecnécio-99m e revisão da literatura

FUNDAMENTOS: A progressão linfática do melanoma maligno habitualmente se inicia pelo linfonodo sentinela (LNS), cuja análise histopatológica permite predizer o acometimento de toda a cadeia. OBJETIVO: O trabalho tem por objetivo descrever a utilização do 99mTc-Fitato na detecção do LNS em pacientes com melanoma maligno, revisando as indicações e informações fornecidas por sua biópsia. MÉTODO: A pesquisa de LNS foi realizada por meio da linfocintilografia com 99mTc-Fitato em 92 pacientes com melanoma (54,0±14,3 anos). Após 18-24 horas, 88 pacientes foram submetidos à localização intra-operatória com detector portátil, seguida da ressecção e análise histopatológica do LNS. RESULTADOS: A linfocintilografia permitiu a identificação do LNS em todos os estudos, havendo detecção intra-operatória em 98,8% dos casos. O LNS estava acometido em 23 pacientes (26%). O valor preditivo negativo foi de 100% e não se observaram reações adversas pelo uso do 99mTc-Fitato. CONCLUSÃO: A detecção do LNS pode ser realizada com diferentes radiofármacos, incluindo o 99mTc-Fitato, que apresenta vantagens de custo e disponibilidade no Brasil. A pesquisa de LNS resulta em maior acurácia e menor morbidade no estadiamento de pacientes com melanoma maligno

Sentinel lymph nodes in a swine model with melanoma: contrast-enhanced lymphatic US

PURPOSE

To determine if lymphatic channels and sentinel lymph nodes (SLNs) with and without metastases can be detected with lymphatic ultrasonography (US) after peritumoral injection of a US contrast agent and to determine if lymphatic US can be used to assess SLNs for the presence of metastatic infiltration.

MATERIALS AND METHODS

Six swine with 17 melanomas were evaluated. Conventional gray-scale, color flow, and gray-scale phase-inversion harmonic US examinations were performed. A US contrast agent was administered in four sites around each melanoma (1-mL total dose). Lymphoscintigraphy was followed by injection of a blue dye and then dissection. SLNs identified at lymphatic US were characterized by two readers in consensus as normal or as having metastases; results were compared with histologic findings. Statistical analyses included the sign test and the kappa statistic.

RESULTS

Lymphatic US depicted 28 SLNs, while lymphoscintigraphy depicted 27 "hot spots" suspected of representing SLNs (including two false-positive findings). Dissection after blue dye injection helped identify 31 SLNs. There were no false-positive US findings for SLN detection. Five of six nodes not seen with lymphoscintigraphy were detected with lymphatic US. The accuracy of SLN detection was 90% (28 of 31) for lymphatic US and 81% (25 of 31) for lymphoscintigraphy (P =.29). Lymphatic US correctly depicted metastases in 19 of 20 SLNs, and five of the eight normal SLNs were correctly characterized, with an accuracy of 86% (kappa = 0.62).

CONCLUSION

Detection of SLNs with lymphatic US compared favorably with that at lymphoscintigraphy. Lymphatic US can depict metastases within the SLN, which was not possible with lymphoscintigraphy.

Further data on the usefulness of sentinel lymph node identification and ultrastaging in vulvar squamous cell carcinoma

OBJECTIVE

The aim was to determine the feasibility of surgical identification and pathological ultrastaging of sentinel nodes (SNs) in vulvar carcinoma and to evaluate whether SN negativity rules out the possibility of metastasis in other nodes and can therefore avoid conventional lymphadenectomy.

MATERIAL AND METHODS

In 26 patients with vulvar squamous cell carcinoma the SNs were detected using both peritumoral injection of (99m)Tc and blue dye (isosulfan or methylene) before the surgical procedure. Dissection of the SNs was followed by standard lymphadenectomy and vulvar exeresis. For pathological ultrastaging at least eight histological sections of every node separated 400 microm were evaluated using hematoxylin & eosin and immunostaining against cytokeratin.

RESULTS

We identified the SNs in 25/26 patients (96%). In 19 patients (76%) the SN was unilateral and in 6 (24%) it was bilateral. A total of 46 SNs were isolated. Metastatic carcinoma was identified in 9 SNs from 8 patients (30.8%). Thirty-eight percent (3 of 8) patients with metastatic SNs presented micrometastasis detected only in ultrastaging. Seven (3.3%) of 239 nonsentinel nodes (non-SNs) showed metastasis. No metastatic implant was detected in non-SNs when SNs were negative in patients without clinical suspicious adenopathy (100% negative predictive value).

CONCLUSION

Inguinofemoral lymph nodes can be confidently avoided when sentinel node metastases are excluded by histological ultrastaging. This may reduce the surgical morbidity of conventional inguinofemoral lymphadenectomy, without worsening vulvar cancer prognosis.