Surgery and sentinel lymph node biopsy

Mesenchymal-epithelial transition factor (MET) immunoreactivity in positive sentinel nodes from patients with melanoma

OBJECTIVE

Patients with cutaneous melanoma and a positive sentinel node (SN) are currently eligible for adjuvant treatment with targeted therapy and immune checkpoint inhibitors. Near-infrared (NIR) fluorescence imaging could be an alternative and less invasive tool for SN biopsy to select patients for adjuvant treatment. One potential target for NIR is the mesenchymal-epithelial transition factor (MET). This study aimed to assess MET immunoreactivity in positive SNs and to evaluate its potential diagnostic, prognostic and therapeutic value.

METHODS

In this retrospective study, positive SN samples from patients with primary cutaneous melanoma were collected to assess MET immunoreactivity. To this end, paraffin-embedded SNs were stained for MET (monoclonal antibody D1C2). A 4-point Histoscore was used to determine cytoplasmic and membranous immunoreactivity (0 negative/1 weak/2 moderate/3 strong). Samples were considered positive when ≥10% of the cancer cells showed MET expression (staining intensity ≥1). Patient and clinicopathological characteristics were used for descriptive statistics, binary logistic regression, and survival analyses.

RESULTS

Positive MET immunohistochemistry was observed in 24 out of 37 samples (65%). No statistically significant associations were found between MET positivity and the following prognostic factors: Breslow thickness (P = 0.961), ulceration (P = 1.000), and SN tumor burden (P = 0.792). According to MET positivity, Kaplan-Meier curves showed no significant differences in survival.

CONCLUSION

This exploratory study found no evidence to support MET immunoreactivity in positive SNs as a possible diagnostic or prognostic indicator in patients with melanoma.

Indocyanine Green for Leakage Control in Isolated Limb Perfusion

Sarcomas are characterized by a high metastatic potential and aggressive growth. Despite surgery, chemotherapy plays an important role in the treatment of these tumors. Optimal anti-cancer therapy with maximized local efficacy and minimized systemic side effects has been the object of many studies for a long time. To improve the local efficacy of anti-tumor therapy, isolated limb perfusion with high-dose cytostatic agents has been introduced in surgical oncology. In order to control the local distribution of substances, radiolabeled cytostatic drugs or perfusion solutions have been applied but often require the presence of specialized personnel and result in a certain exposure to radiation. In this study, we present a novel strategy using indocyanine green to track tumor perfusion with high-dose cytostatic therapy. In a rat cadaver model, the femoral vessels were cannulated and connected to a peristaltic pump to provide circulation within the selected limb. The perfusion solution contained indocyanine green and high-dose doxorubicin. An infrared camera enabled the visualization of indocyanine green during limb perfusion, and subsequent leakage control was successfully performed. Histologic analysis of sections derived proximally from the injection site excluded systemic drug dispersion. In this study, the application of indocyanine green was proven to be a safe and cost- and time-efficient method for precise leakage control in isolated limb perfusion with a high-dose cytostatic agent.

Primary Melanoma: from History to Actual Debates

PURPOSE OF REVIEW

This review describes the long scientific background followed to design guidelines and everyday clinical practice applied to melanoma patients. Surgery is the first option to cure melanoma patients (PTS) at initial diagnosis, since primary cutaneous lesions are usually easily resectable. An excisional biopsy of the lesion, with minimal clear margins, can be obtained in the vast majority of cases. Punch biopsies may be proposed only in case of large lesions located on specific cosmetic or functional areas like the face, extremities, or genitals where a mutilating complete resection would not be performed without prior histological diagnosis.

RECENT FINDINGS

After the histologic confirmation of melanoma, definite surgical excision of the scar and surrounding tissue is planned, to obtain microsatellite free margins. The width of these margins has been identified following the results of several clinical trials and it is either 1 or 2 cm, depending on the Breslow thickness of the primary tumor. Following the latest staging system proposed by the American Joint Cancer commission (AJCC), a sentinel node biopsy (SNB) is usually performed in case of a primary lesion > 0.8 mm thickness or for high-risk thinner lesions, if no evidence of nodal involvement has been identified clinically or radiographically. Surgical management of primary melanoma is well established. There is debate on the optimal surgical margins for 1-2 mm melanomas. There are specific considerations for special primaries (bulky, extremity, mucosal). Sentinel node (SN) evaluation does not improve survival, but is routinely used as staging.

Dermoscopy structures as predictors of sentinel lymph node positivity in cutaneous melanoma

BACKGROUND

Histological features such as Breslow thickness, ulceration and mitosis are the main criteria to guide sentinel lymph node biopsy (SLNB) in melanoma. Dermoscopy may add complementary information to these criteria.

OBJECTIVES

To evaluate the correlation between dermoscopy structures and SLNB positivity.

METHODS

Retrospective analysis of 123 consecutive melanomas with Breslow thickness > 0·75 mm, SLNB performed during follow-up and dermoscopic images.

RESULTS

Men were more likely to have a positive SLNB. The presence of ulceration and blotch and the absence of a pigmented network in dermoscopy correlated with positive SLNB. Histological ulceration also correlated with positive SLNB. A dermoscopy SCORE predicted SLN status with a sensitivity of 96·3% and a specificity of 30·2%. When sex and Breslow thickness were added (SCOREBRESEX), the sensitivity remained at 96·3% but the specificity increased to 52·1%. This study is limited by the number of patients and was performed in only one institution.

CONCLUSIONS

Dermoscopy allowed a more precise prediction of SLN status. If a combined SCOREBRESEX was used to select patients for SLNB, 41·5% of procedures might be avoided.

Optimization via specific fluorescence brightness of a receptor-targeted probe for optical imaging and positron emission tomography of sentinel lymph nodes

The optical properties of a receptor-targeted probe designed for dual-modality mapping of the sentinel lymph node (SLN) was optimized. Specific fluorescence brightness was used as the design criterion, which was defined as the fluorescence brightness per mole of the contrast agent. Adjusting the molar ratio of the coupling reactants, IRDye 800CW-NHS-ester and tilmanocept, enabled us to control the number of fluorescent molecules attached to each tilmanocept, which was quantified by H1 nuclear magnetic resonance spectroscopy. Quantum yields and molar absorptivities were measured for unconjugated IRDye 800CW and IRDye 800CW-tilmanocept (800CW-tilmanocept) preparations at 0.7, 1.5, 2.3, 2.9, and 3.8 dyes per tilmanocept. Specific fluorescence brightness was calculated by multiplication of the quantum yield by the molar absorptivity and the number of dyes per tilmanocept. It predicted that the preparation with 2.3 dyes per tilmanocept would exhibit the brightest signal, which was confirmed by fluorescence intensity measurements using three optical imaging systems. When radiolabeled with Ga68 and injected into the footpads of mice, the probe identified SLNs by both fluorescence and positron emission tomography (PET) while maintaining high percent extraction by the SLN. These studies demonstrated the feasibility of 800CW-tilmanocept for multimodal SLN mapping via fluorescence and PET-computed tomography imaging.

Comparative evaluation of [(99m)tc]tilmanocept for sentinel lymph node mapping in breast cancer patients: results of two phase 3 trials

BACKGROUND

Sentinel lymph node (SLN) surgery is used worldwide for staging breast cancer patients and helps limit axillary lymph node dissection. [(99m)Tc]Tilmanocept is a novel receptor-targeted radiopharmaceutical evaluated in 2 open-label, nonrandomized, within-patient, phase 3 trials designed to assess the lymphatic mapping performance.

METHODS

A total of 13 centers contributed 148 patients with breast cancer. Each patient received [(99m)Tc]tilmanocept and vital blue dye (VBD). Lymph nodes identified intraoperatively as radioactive and/or blue stained were excised and histologically examined. The primary endpoint, concordance (lower boundary set point at 90 %), was the proportion of nodes detected by VBD and [(99m)Tc]tilmanocept.

RESULTS

A total of 13 centers contributed 148 patients who were injected with both agents. Intraoperatively, 207 of 209 nodes detected by VBD were also detected by [(99m)Tc]tilmanocept for a concordance rate of 99.04 % (p < 0.0001). [(99m)Tc]tilmanocept detected a total of 320 nodes, of which 207 (64.7 %) were detected by VBD. [(99m)Tc]Tilmanocept detected at least 1 SLN in more patients (146) than did VBD (131, p < 0.0001). In 129 of 131 patients with ≥1 blue node, all blue nodes were radioactive. Of 33 pathology-positive nodes (18.2 % patient pathology rate), [(99m)Tc]tilmanocept detected 31 of 33, whereas VBD detected only 25 of 33 (p = 0.0312). No pathology-positive SLNs were detected exclusively by VBD. No serious adverse events were attributed to [(99m)Tc]tilmanocept.

CONCLUSION

[(99m)Tc]Tilmanocept demonstrated success in detecting a SLN while meeting the primary endpoint. Interestingly, [(99m)Tc]tilmanocept was additionally noted to identify more SLNs in more patients. This localization represented a higher number of metastatic breast cancer lymph nodes than that of VBD.

A receptor-targeted fluorescent radiopharmaceutical for multireporter sentinel lymph node imaging

PURPOSE

To determine the imaging and receptor-binding properties of a multireporter probe designed for sentinel lymph node (SLN) mapping via nuclear and fluorescence detection.

MATERIALS AND METHODS

The animal experiments were approved by the institutional animal care and use committee. A multireporter probe was synthesized by covalently attaching cyanine 7 (Cy7), a near-infrared cyanine dye, to tilmanocept, a radiopharmaceutical that binds to a receptor specific to recticuloendothelial cells. In vitro binding assays of technetium 99m (99mTc)-labeled Cy7 tilmanocept were conducted at 4°C by using receptor-bearing macrophages. Optical SLN imaging after foot pad administration was performed by using two molar doses of Cy7 tilmanocept. Six mice were injected with 0.11 nmol of 99mTc-labeled Cy7 tilmanocept (low-dose group); an additional six mice were injected with 31 nmol of 99mTc-labeled Cy7 tilmanocept (high-dose group) to saturate the receptor sites within the SLN. After 2.5 hours of imaging, the mice were euthanized, and the sentinel and distal lymph nodes were excised and assayed for radioactivity for calculation of SLN percentage of injected dose and extraction. Four mice were used as controls for autofluorescence. Standard optical imaging software was used to plot integrated fluorescence intensity against time for calculation of the SLN uptake rate constant and scaled peak intensity. Significance was calculated by using the Student t test.

RESULTS

In vitro binding assays showed subnanomolar affinity (mean dissociation constant, 0.25 nmol/L±0.10 [standard deviation]). Fluorescence imaging showed a detection sensitivity of 1.6×10(3) counts·sec(-1)·μW(-1) per picomole of Cy7. All four imaging metrics (percentage of injected dose, SLN extraction, SLN uptake rate constant, and expected peak fluorescence intensity) exhibited higher values (P=.005 to P=.042) in the low-dose group than in the high-dose group; this finding was consistent with receptor-mediated image formation.

CONCLUSION

The multireporter probe 99mTc-labeled Cy7 tilmanocept exhibits in vitro and in vivo receptor-binding properties for successful receptor-targeted SLN mapping with nuclear and optical imaging.

Advances in sentinel lymph node mapping for patients with melanoma

Sentinel lymph node mapping allows accurate pathological staging for patients with cutaneous melanoma and clinically normal regional nodes. Early technical advances facilitated its widespread acceptance by surgeons. Morbidity as a result of the procedure is well established, but the potential benefit of providing powerful prognostic information outweighs these risks in most patients with intermediate-risk disease.

Setting up an effective and efficient sentinel node biopsy service for malignant melanoma within the NHS

Sentinel lymph node biopsy provides prognostic information for melanoma patients, and the Department of Health states that it should be available across the country by 2012. We review the setting up of a melanoma sentinel lymph node biopsy service with specific consideration to resources, service implications and patient outcomes. In total, 164 patients underwent sentinel lymph node biopsy for melanoma from August 2008 until March 2010. The median time for sentinel lymph node excision was 26 min. The median total operative time, which includes melanoma excision and sentinel node biopsy was 65 min, compared with 22 min for excision of the melanoma performed during the previous 19 months. The complication rate was 8.5%, with only 1.2% requiring operative treatment. After the initial outlay for two gamma probes, it was possible to deliver a cost neutral service within the National Tariff. Despite a significant increase in demand for the service in the second half of the study period, and 106% increase in the number of regional lymphadenectomies, only 1 patient (0.6%) breached the 'Going Further on Cancer Waits' target. In conclusion, a sentinel lymph node biopsy service for malignant melanoma can be effectively delivered within the majority of UK plastic surgery departments.

Prognostication in thin cutaneous melanomas

CONTEXT

While most patients diagnosed with thin cutaneous melanoma will have a good prognosis, nearly 5% will die of their disease. Thin melanomas are common and approximately one-quarter of all melanoma-related deaths result from thin primary tumors. Patients with thin melanoma commonly have sentinel lymph node biopsies that are uncommonly positive.

OBJECTIVE

To review the progress that has been made in the translation of prognostic and predictive biomarkers for patients with thin melanomas by focusing on the developments during the last 5 years in using measures of tumor proliferation. Given the paucity of biomarkers for patients with thin melanoma, we review some of the challenges in the development, validation, and translation of new biomarkers into clinical practice.

DATA SOURCES

Surveillance, Epidemiology and End Results registry data, cohort data from a cancer center's program in melanoma, and focused literature review.

CONCLUSIONS

The presence of dermal mitoses improves prognostication and prediction. To optimize patient management, biomarkers reflecting biologic processes underlying tumor progression will need to be included in panels and risk models, validated, generalized, and ratified.

Sentinel node biopsy in melanoma: technical considerations of the procedure as performed at the John Wayne Cancer Institute

Since its first description in 1990, sentinel node (SN) biopsy has become the standard for accurate staging of a melanoma-draining regional lymphatic basin. This minimally invasive, multidisciplinary technique can detect occult metastases by selective sampling and focused pathologic analysis of the first nodes on the afferent lymphatic pathway from a primary cutaneous melanoma. An understanding of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and the definition of SN are critical for surgical expertise with SN biopsy.

[Brazilian gamma detection device for sentinel lymph node biopsy]

OBJECTIVE

To test the effectiveness of an intra-operative gamma detection Brazilian device (IPEN) on sentinel lymph node biopsy (SLNB) procedures.

METHODS

Forty melanoma or breast cancer patients with indication for undergoing SLNB were studied. Lymphoscintigraphy was done 2 to 24 hours prior to surgery. Lymphatic mapping with vital dye and gamma detection were performed intraoperatively. For gamma detection Neoprobe 1500 was used followed by IPEN (equipment under test) in the first 20 patients and for the remaining half IPEN was used first to verify its ability to locate the sentinel node (SN). Measurements were taken from the radiopharmaceutical product injection site, from SN (in vivo and ex vivo) and from background. It was recorded if the SN was stained or not and if it was found easily by surgeon.

RESULTS

There were 33 (82.5%) breast cancer and 7 (17.5%) melanoma patients. Ages varied from 21 to 68 year-old (median age of 46). Sex distribution was 35 (87.5%) women and 5 (12.5%) men. Sentinel node was found in all but one patient. There was no statistical difference between the reasons ex vivo/ background obtained with the measures of both equipments (p=0, 2583-ns). The SN was easily found by the surgeon with both devices.

CONCLUSION

The SLNB was successfully performed using either equipment. It was possible to do SLNB with the Brazilian device developed by IPEN without prejudice for the patient.

Sentinel lymph node biopsy in melanoma patients

Appropriate surgical management of regional lymph nodes is critical in patients with cutaneous melanoma. The use of intraoperative lymphatic mapping and sentinel lymph node biopsy (SLNB) has increased significantly in the past decade. SLNB is performed as minimally invasive procedure that provides accurate staging of melanoma patients with no clinically detectable nodal disease. In many melanoma units across the world, it became the standard for detection of occult regional node metastasis in patients with intermediate-thickness primary melanoma. Use of SLNB in patients with thin melanomas is still under evaluation. Although SLNB has been established as staging procedure in melanoma patients, its therapeutic role is still not clear. Large-scale ongoing randomized trials should elucidate whether SLNB with complete lymphadenectomy has a survival benefit in melanoma patients with early lymph node metastases compared to 'watch-and-wait' policy (observation).

Imaging of lymph node micrometastases using an oncolytic herpes virus and [F]FEAU PET

Background

In patients with melanoma, knowledge of regional lymph node status provides important information on outlook. Since lymph node status can influence treatment, surgery for sentinel lymph node (SLN) biopsy became a standard staging procedure for these patients. Current imaging modalities have a limited sensitivity for detection of micrometastases in lymph nodes and, therefore, there is a need for a better technique that can accurately identify occult SLN metastases.

Methodology/Principal Findings

B16-F10 murine melanoma cells were infected with replication-competent herpes simplex virus (HSV) NV1023. The presence of tumor-targeting and reporter-expressing virus was assessed by [¹⁸F]-2′-fluoro-2′-deoxy-1-β-D-β-arabinofuranosyl-5-ethyluracil ([¹⁸F]FEAU) positron emission tomography (PET) and confirmed by histochemical assays. An animal foot pad model of melanoma lymph node metastasis was established. Mice received intratumoral injections of NV1023, and 48 hours later were imaged after i.v. injection of [¹⁸F]FEAU. NV1023 successfully infected and provided high levels of lacZ transgene expression in melanoma cells. Intratumoral injection of NV1023 resulted in viral trafficking to melanoma cells that had metastasized to popliteal and inguinal lymph nodes. Presence of virus-infected tumor cells was successfully imaged with [¹⁸F]FEAU-PET, that identified 8 out of 8 tumor-positive nodes. There was no overlap between radioactivity levels (lymph node to surrounding tissue ratio) of tumor-positive and tumor-negative lymph nodes.

Conclusion/Significance

A new approach for imaging SLN metastases using NV1023 and [¹⁸F]FEAU-PET was successful in a murine model. Similar studies could be translated to the clinic and improve the staging and management of patients with melanoma.

Sentinel node concept in clinically n0 laryngeal and hypopharyngeal cancer

BACKGROUND

Sentinel nodes (SNs) are the lymph nodes that directly receive lymphatic flow from a primary cancer lesion. The SN concept implies that lymphatic metastasis initially occurs at SNs. SN navigation surgery can be introduced for cancers in which the SN concept is established. In SN navigation surgery, lymph node dissection beyond SNs can be omitted if SNs are metastasis free. Although the SN concept has been investigated frequently for oral and oropharyngeal cancer, it has so far been investigated less for laryngeal and hypopharyngeal cancer. In this study, we investigated whether the SN concept is applicable for laryngeal and hypopharyngeal cancer.

METHODS

Twenty patients with T2-T4 and clinically N0 laryngeal and hypopharyngeal cancer were recruited. (99m)Tc-phytate was injected into several sites surrounding the tumor on the day before surgery. Lymphoscintigrams were acquired from at least two different viewpoints. SNs were surveyed intraoperatively, and neck dissections including at least levels II, III, and IV were performed.

RESULTS

SNs had occult metastases in five cases. In the remaining 15 cases, neither SNs nor other lymph nodes contained metastases, consistent with the SN concept. There was one false-negative case showing delayed nodal metastasis 2 years after initial surgery. The overall accuracy of the SN concept was 95%.

CONCLUSION

Our study shows that SN biopsy is a reliable strategy to determine correct lymph node status in N0 laryngeal and hypopharyngeal cancer. SN detection was valuable in evaluating the need for neck dissection, whether ipsilaterally or bilaterally.