Sentinel lymph node detection using methylene blue in patients with early stage cervical cancer

Effectiveness of sentinel lymph node biopsy and bilateral pelvic nodal dissection using methylene blue dye in early-stage operable cervical cancer-A prospective study

OBJECTIVE

To evaluate the effectiveness of methylene blue dye in detecting sentinel lymph nodes (SLNs) in women with early-stage operable (defined as FIGO I-IIA) cervical cancer. It also aims to evaluate procedural challenges and accuracy.

METHOD

This prospective study, which focused on 20 women with early-stage cervical cancer, was carried out between June 2016 and December 2017. These patients had SLN mapping with methylene blue dye injections and thorough examinations, including imaging. All patients underwent radical hysterectomy and complete bilateral pelvic lymphadenectomy. No additional investigation was done on the lymph node in cases where a metastasis was found in the first H&E-stained segment of the sentinel node.

RESULT

20 patients were included in the analysis. The median age of the subjects was 53, and 95 % of them had squamous cell carcinoma. 90 % of the time, the identification of SLNs was effective, and 55 SLNs were found, of which 52.7 % were on the right side of the pelvis and 47.3 % on the left. The obturator group had the most nodes, followed by the external and internal iliac groups in descending order of occurrence. Metastasis was detected in 3 patients, resulting in a sensitivity of 100 % and a specificity of 93.75 % for SLN biopsy. Notably, no false-negative SLNs were found. Complications related to methylene blue usage included urine discoloration in 30 % of patients.

CONCLUSION

This trial highlights the promising efficacy and safety of methylene blue dye alone for SLN identification in early-stage operable cervical cancer, with a notably higher success rate. Despite limitations like a small sample size, healthcare professionals and researchers can build upon the insights from this study to enhance cervical cancer management.

Diagnostic value of sentinel lymph node scintigraphy and 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in the detection of metastatic lymph nodes in patients with early-stage cervical cancer

Cervical cancer is staged clinically using the International Federation of Gynaecology and Obstetrics staging system. Although lymph node status does not form part of the staging, it has important prognostic and potential therapeutic implications. The aim of the study was to evaluate the role of sentinel lymph node (SLN) scintigraphy and 2-[¹⁸F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in detecting lymph node metastases in patients with early-stage cervical cancer. Thirty-six patients with early-stage cervical cancer underwent SLN detection during primary operation. Of the 36 patients, 28 patients underwent ¹⁸F-FDG PET/CT before surgery. The ¹⁸F-FDG PET/CT images were analyzed with the histopathological findings as the reference standard. The diagnostic performance of ¹⁸F-FDG PET/CT in the detection of nodal disease was reported in terms of accuracy value. The SLN detection rate was the highest (91.7%) using the combined method (lymphoscintigraphy, intraoperative gamma probe, and blue dye). Seven of the thirty-six patients had lymph node involvement (19.4%), of which five had preoperative ¹⁸F-FDG PET/CT imaging. On overall patient-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of ¹⁸F-FDG PET/CT were 40.0%, 78.3%, 28.6%, 85.7%, and 71.4%, respectively. The combination of radiolabeled nanocolloid with blue dye is safe and reliable and allows successful detection of SLNs in patients with early-stage cervical cancer in a population with high prevalence of human immunodeficiency virus. The specificity and NPV of ¹⁸F-FDG PET/CT are high and can be used in conjunction with SLN biopsy.

Pathologic Protocols for Sentinel Lymph Nodes Ultrastaging in Cervical Cancer

CONTEXT.—

Ultrastaging of sentinel lymph nodes (SLNs) is a crucial aspect in the approach to SLN processing. No consensual protocol for pathologic ultrastaging has been approved by international societies to date.

OBJECTIVE.—

To provide a review of the ultrastaging protocol and all its aspects related to the processing of SLNs in patients with cervical cancer.

DATA SOURCES.—

In total, 127 publications reporting data from 9085 cases were identified in the literature. In 24% of studies, the information about SLN processing is entirely missing. No ultrastaging protocol was used in 7% of publications. When described, the differences in all aspects of SLN processing among the studies and institutions are substantial. This includes grossing of the SLN, which is not completely sliced and processed in almost 20% of studies. The reported protocols varied in all aspects of SLN processing, including the thickness of slices (range, 1-5 mm), the number of levels (range, 0-cut out until no tissue left), distance between the levels (range, 40-1000 μm), and number of sections per level (range, 1-5).

CONCLUSIONS.—

We found substantial differences in protocols used for SLN pathologic ultrastaging, which can impact sensitivity for detection of micrometastases and even small macrometastases. Since the involvement of pelvic lymph nodes is the most important negative prognostic factor, such profound discrepancies influence the referral of patients to adjuvant radiotherapy and could potentially cause treatment failure. It is urgent that international societies agree on a consensual protocol before SLN biopsy without pelvic lymphadenectomy is introduced into routine clinical practice.

Use of a Sentinel Lymph Node Biopsy Algorithm in a South African Population of Patients With Cervical Cancer and High Prevalence of Human Immunodeficiency Virus Infection

OBJECTIVES

Cervical cancer is common in resource-poor settings with high prevalence of tuberculosis, pelvic inflammatory disease, and human immunodeficiency virus (HIV) infection. There are no data regarding the sentinel lymph node (SLN) algorithm in these high-risk cancer populations. Our objectives were to establish the sensitivity, specificity, positive predictive value, and negative predictive value of the SLN algorithm in cervical cancer and to compare the detection rate of indocyanine green (ICG) versus blue dye versus technetium Tc 99m nanocolloid (Tc).

METHODS

This prospective study was conducted at the University of Pretoria. Tc-nanocolloid tracer, ICG dye, and methylene blue (MB) were used to detect SLNs. Pathological ultrastaging was performed on hematoxylin-eosin- negative nodes.

RESULTS

Results of 72 women were analyzed. The mean age was 47.2 years, 5.5% had a history of tuberculosis, 18.1% had pelvic inflammatory disease, and 65.3% were HIV positive. The SLN detection rate was 65.3%. Detection rate of MB was 56.9%; Tc, 69.4%; ICG, 87.5%; and the combination of MB and Tc, 91.7%. Pelvic nodal metastases occurred in 26.4%. The sensitivity, specificity, negative predictive value, and positive predictive value of SLN biopsy were 85.7%, 100%, 100%, and 98.33%, respectively. The false-negative rate was 14.3%, and it was 0% if the algorithm was applied.

CONCLUSIONS

The SLN algorithm is a feasible option for use in cervical cancer women with a high prevalence of HIV infection. The detection rate is generally lower, but in select subgroups of women, it was comparable to that reported elsewhere. This is the first report of the use of SLN biopsy in a substantial group of HIV-infected women.

Sentinel lymphatic mapping among women with early-stage cervical cancer: A systematic review

The presence of pelvic lymph node metastases is without doubt the most significant prognostic factor that determines recurrences and survival of women with early-stage cervical cancer. To avoid the underdiagnosis of lymph node metastasis, pelvic lymphadenectomy procedure is routinely performed with radical hysterectomy procedure. However, the pelvic lymphadenectomy procedure may not be necessary in most of these women due to the relatively low incidence of pelvic lymph node metastasis. The removal of large numbers of pelvic lymph nodes could also render non-metastatic irreversible damages for these women, including vessel, nerve, or ureteral injuries; formation of lymphocysts; and lymphedema. Over the past decades, the concept of sentinel lymph node biopsy has emerged as a popular and widespread surgical technique for the evaluation of the pelvic lymph node status in gynecologic malignancies. The histological status of sentinel lymph node should be representative for all other lymph nodes in the regional drainage area. If metastasis is non-existent in the sentinel lymph node, the likelihood of metastatic spread in the remaining regional lymph nodes is very low. Further lymphadenectomy is therefore not necessary for a patient with negative sentinel lymph nodes. Since the uterine cervix has several lymphatic drainage pathways, it is a challenging task to assess the distribution pattern of sentinel lymph nodes in women with early-stage cervical cancer. This review article will adapt the methodology proposed in these studies to systematically review sentinel lymphatic mapping among women with early-stage cervical cancer.

Sentinel Lymph Node Biopsy in Pelvic Tumors: Clinical Indications and Protocols Under Investigation

Sentinel lymph node (SLN) sampling is an attractive alternative to complete lymphadenectomy. Based on the identification and sampling of the first LN draining a primary tumor, SLN biopsy is the most accurate and the only reliable method for microscopic nodal staging for solid tumors including breast cancer and melanoma. Lymph node status in pelvic tumors remains the most important prognostic factor for recurrence and survival and a major decision criterion for adjuvant therapy. We review the clinical indications, controversies, and perspective of SLN biopsy in male and female pelvic cancers.

Experimental Study of Magnetic Multi-Walled Carbon Nanotube-Doxorubicin Conjugate in a Lymph Node Metastatic Model of Breast Cancer

BACKGROUND The lymphatic system plays a significant role in the defense of a subject against breast cancer and is one of the major pathways for the metastasis of breast cancer. To improve the prognosis, many means, including surgery, radiotherapy, and chemotherapy, have been used. However, the combination of all these modalities has limited efficacy. Lymph nodes, therefore, have become an exceptionally potential target organ in cancer chemotherapy. MATERIAL AND METHODS A lymph node metastatic model of breast cancer was established in BALB/c mice. Magnetic multi-walled carbon nanotube carrier with good adsorption and lymph node-targeting capacity was prepared and conjugated with doxorubicin to make the magnetic multi-walled carbon nanotube-doxorubicin suspension. Dispersions of doxorubicin, magnetic multi-walled carbon nanotube-doxorubicin, and magnetic multi-walled carbon nanotube were injected into lymph node metastatic mice to compare their inhibitory effects on tumor cells in vivo. Inhibition of these dispersions on EMT-6 breast cancer cells was detected via MTT assay in vitro. RESULTS Although no significant difference was found between the effects of doxorubicin and magnetic multi-walled carbon nanotube-doxorubicin with the same concentration of doxorubicin on EMT-6 breast cancer cells in vitro, in terms of sizes of metastatic lymph nodes and xenograft tumors, apoptosis in metastatic lymph nodes, and adverse reactions, the magnetic multi-walled carbon nanotube-doxorubicin group differed significantly from the other groups. CONCLUSIONS The magnetic multi-walled carbon nanotube-doxorubicin clearly played an inhibitory role in lymph node metastases to EMT-6 breast cancer cells.

Sentinel Lymph Node Detection Using Carbon Nanoparticles in Patients with Early Breast Cancer

PURPOSE

Carbon nanoparticles have a strong affinity for the lymphatic system. The purpose of this study was to evaluate the feasibility of sentinel lymph node biopsy using carbon nanoparticles in early breast cancer and to optimize the application procedure.

METHODS

Firstly, we performed a pilot study to demonstrate the optimized condition using carbon nanoparticles for sentinel lymph nodes (SLNs) detection by investigating 36 clinically node negative breast cancer patients. In subsequent prospective study, 83 patients with clinically node negative breast cancer were included to evaluate SLNs using carbon nanoparticles. Another 83 SLNs were detected by using blue dye. SLNs detection parameters were compared between the methods. All patients irrespective of the SLNs status underwent axillary lymph node dissection for verification of axillary node status after the SLN biopsy.

RESULTS

In pilot study, a 1 ml carbon nanoparticles suspension used 10-15min before surgery was associated with the best detection rate. In subsequent prospective study, with carbon nanoparticles, the identification rate, accuracy, false negative rate was 100%, 96.4%, 11.1%, respectively. The identification rate and accuracy were 88% and 95.5% with 15.8% of false negative rate using blue dye technique. The use of carbon nanoparticles suspension showed significantly superior results in identification rate (p = 0.001) and reduced false-negative results compared with blue dye technique.

CONCLUSION

Our study demonstrated feasibility and accuracy of using carbon nanoparticles for SLNs mapping in breast cancer patients. Carbon nanoparticles are useful in SLNs detection in institutions without access to radioisotope.

Sentinel-lymph-node procedures in early stage cervical cancer: a systematic review and meta-analysis

We performed a meta-analysis to assess the accuracy of sentinel-lymph-node (SLN) procedures for the assessment of nodal metastases in patients with early stage cervical cancer. Studies of SLN procedures for detecting nodal metastases in patients with early stage cervical cancer were systematically searched in MEDLINE and EMBASE between January 1, 2000 and August 30, 2013. We identified 49 eligible studies, which included 2,476 SLN procedures. The mean overall weighted-detection rate was 0.93 (95 % CI 0.92–0.94), at a pooled sensitivity of 0.88 (95 % CI 0.84–0.90) with limited heterogeneity (χ² = 80.57, degrees of freedom = 47, p = 0.002). Subgroup analysis of sensitivity and the rate of detection of different tracer techniques and surgery methods used in conjunction with an SLN procedures were as follows: studies using combined techniques, 0.88 (95 % CI 0.84–0.91) and 0.97 (95 % CI 0.96–0.98); studies using metastable technetium-99, 0.87 (95 % CI 0.78–0.93) and 0.90 (95 % CI 0.87–0.93); studies using blue dye, 0.87 (95 % CI 0.79–0.93) and 0.87 (95 % CI 0.84–0.90); studies using laparotomy, 0.86 (95 % CI 0.80–0.90) and 0.87 (95 % CI 0.83–0.91); studies using laparoscopy, 0.90 (95 % CI 0.86–0.94) and 0.93 (95 % CI 0.90–0.96); and studies using robot-assisted surgery, 0.84 (95 % CI 0.72–0.92) and 0.92 (95 % CI 0.88–0.95). We concluded that the SLN procedure performs well diagnostically for the assessment of nodal metastases in patients with early stage cervical cancer.

Sentinel node biopsy for lymph nodal staging of uterine cervix cancer: a systematic review and meta-analysis of the pertinent literature

BACKGROUND

We reviewed the available literature on the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers.

METHODS

MEDLINE and Scopus were searched by using "sentinel AND (cervix OR cervical)" as key words. Studies evaluating the accuracy of sentinel node mapping in the lymph nodal staging of uterine cervical cancers were included if enough data could be extracted for calculation of detection rate and/or sensitivity.

RESULTS

Sixty-seven studies were included in the systematic review. Pooled detection rate was 89.2% [95% CI: 86.3-91.6]. Pooled sensitivity was 90% [95% CI: 88-92]. Sentinel node detection rate and sensitivity were related to mapping method (blue dye, radiotracer, or both) and history of pre-operative neoadjuvant chemotherapy. Sensitivity was higher in patients with bilaterally detected pelvic sentinel nodes compared to those with unilateral sentinel nodes. Lymphatic mapping could identify sentinel nodes outside the routine lymphadenectomy limits.

CONCLUSION

Sentinel node mapping is an accurate method for the assessment of lymph nodal involvement in uterine cervical cancers. Selection of a population with small tumor size and lower stage will ensure the lowest false negative rate. Lymphatic mapping can also detect sentinel nodes outside of routine lymphadenectomy areas providing additional histological information which can improve the staging. Further studies are needed to explore the impact of sentinel node mapping in fertility sparing surgery and in patients with history of neoadjuvant chemotherapy.

Establishing a sentinel lymph node mapping algorithm for the treatment of early cervical cancer

OBJECTIVE

To establish an algorithm that incorporates sentinel lymph node (SLN) mapping to the surgical treatment of early cervical cancer, ensuring that lymph node (LN) metastases are accurately detected but minimizing the need for complete lymphadenectomy (LND).

METHODS

A prospectively maintained database of all patients who underwent SLN procedure followed by a complete bilateral pelvic LND for cervical cancer (FIGO stages IA1 with LVI to IIA) from 03/2003 to 09/2010 was analyzed. The surgical algorithm we evaluated included the following: 1. SLNs are removed and submitted to ultrastaging; 2. any suspicious LN is removed regardless of mapping; 3. if only unilateral mapping is noted, a contralateral side-specific pelvic LND is performed (including inter-iliac nodes); and 4. parametrectomy en bloc with primary tumor resection is done in all cases. We retrospectively applied the algorithm to determine how it would have performed.

RESULTS

One hundred twenty-two patients were included. Median SLN count was 3 and median total LN count was 20. At least one SLN was identified in 93% of cases (114/122), while optimal (bilateral) mapping was achieved in 75% of cases (91/122). SLN correctly diagnosed 21 of 25 patients with nodal spread. When the algorithm was applied, all patients with LN metastasis were detected; with optimal mapping, bilateral pelvic LND could have been avoided in 75% of cases.

CONCLUSIONS

In the surgical treatment of early cervical cancer, the algorithm we propose allows for comprehensive detection of all patients with nodal disease and spares complete LND in the majority of cases.

Guided surgical debridement: staining tissues with methylene blue

Precise surgical debridement of wounds is required to achieve wound closure. The authors describe their experience with a technique using topical methylene blue to facilitate precise surgical debridement. In this technique, methylene blue dye is applied topically to the wound surface at the onset of surgery. The stained wound site is then wiped to remove dye from the surface of normal epithelium; eschar, nonviable tissue, and granulation tissue remain stained. The methylene blue-stained tissue is surgically removed, and the newly debrided surface of the wound is assessed for adequate vascularity and biopsied to verify presence of bacteriologic balance before closure. The authors have used this technique in more than 200 wound debridements during the past year, including acute surgical or traumatic wounds, acute and subacute burn wounds, chronic granulating wounds, partially epithelialized wounds, sinus tracts, and fistulae. No adverse reactions have been noted, even on patients undergoing multiple applications through serial operations. Topical application of methylene blue to wounds with mixed tissue content helps to distinguish between viable and nonviable tissue and between epithelialized and nonepithelialized areas, facilitating more precise and complete wound debridement.

Sentinel node (SLN) biopsy in the management of locally advanced cervical cancer

OBJECTIVES

Sentinel lymph node (SLN) biopsy can significantly contribute to the management of locally advanced cervical cancers with high risk of lymph node (LN) positivity. However, low detection rate and sensitivity were reported in larger tumors, albeit on a small number of cases. It was the aim of our study to verify the SLN reliability in large tumors, with modified dye application technique and a careful identification of side-specific lymphatic drainage.

METHODS

The study involved 44 patients with tumors 3 cm in diameter or larger, stages IB1 to IIA, or selected IIB. In cases where SLN could not be detected, systematic pelvic lymphadenectomy was performed on the respective side. Systematic pelvic lymphadenectomy was performed during the second step radical procedure if not already done.

RESULTS

Detection rate in the whole cohort reached 77% per patient and 59% bilaterally. No significant difference was found whether a blue dye or a combined method was used (75% vs 80%, and 55% vs 67%). Systematic pelvic lymphadenectomy was performed in cases with undetected SLN unilaterally in 8 and bilaterally in 10 women. A systematic pelvic lymphadenectomy was included in the second step radical procedure in 19 cases and no positive LN were found. There was no case of false-negative SLN result in patients who underwent surgical treatment.

CONCLUSION

Detection rate in locally advanced cervical cancer could be improved by a careful dye application technique. Low false-negative SLN rate could be achieved if pelvic lymphatic drainage is evaluated on a side-specific principle by performing systematic lymphadenectomy if SLN is not detected.

Sentinel lymph node mapping using near-infrared fluorescent methylene blue

Methylene blue (MB) is a safe, low cost, and common blue dye remaining a popular choice for sentinel lymph node (SLN) mapping. However, the blue-dyed SLN in deep animal tissue could be seen only after a surgical management. Here the fluorescence properties of MB were investigated using a fluorescence spectrometer and a wavelength-resolved fluorescence spectral in vivo imaging system, and MB has been demonstrated for near-infrared (NIR) fluorescence mapping of SLN. When MB was injected intradermally into the second row breast of a rabbit, the lymphatic flow and axillary SLN could be observed directly through the NIR fluorescence emitted from the MB trapped in the deep tissue, which would eliminate the need for surgical management, and this fluorescence without any radioactivity was retained in the SLN for hours. The node also could be identified synchronously by the blue color and fluorescence of the MB after a surgical management. Using MB NIR fluorescence for SLN mapping may have great advantages over the traditional method.

Molecular diagnosis of sentinel lymph node metastases in cervical cancer using squamous cell carcinoma antigen

PURPOSE

To clarify the prognostic value of molecular diagnosis of SLN metastases in cervical cancer using SCCA.

EXPERIMENTAL DESIGN

All SLNs and primary tumors, part of non-SLNs, were harvested from 36 patients with cervical cancer. Expression levels of SCCA, cytokeratin 19 (CK19), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA in 178 samples (29 primary tumors, 5 histologic positive nodes, 60 histologic negative SLNs, 69 non-SLNs, and 15 normal nodes) were assessed by quantitative reverse transcription-PCR assay. The quantitative value of SCCA or CK19 mRNA was described as each value relative to GAPDH mRNA. The cutoff value was set at the upper limit of the quantitative value of nodes from noncancer patients, and those above this value constituted the molecular metastasis group.

RESULTS

The SCCA mRNA expression values were more than 1 x 10(3) in 28 primary tumors and all histologic positive nodes, and its expression levels in SLNs were higher than in non-SLNs. SLNs from patients with adverse prognostic features had higher SCCA mRNA expression levels. Four histologic negative SLNs were diagnosed molecular metastases based on SCCA mRNA. Two cases with histologically uninvolved pelvic nodes recurred. Survival analysis indicates that molecular lymphatic metastasis based on elevated SCCA mRNA level is the best predictor of recurrence. However, CK19 is not a suitable marker due to its low specificity and relative higher baseline expression in normal nodes.

CONCLUSIONS

SCCA mRNA levels for molecular diagnosis of SLN metastases in cervical cancer more accurately identifies patients at risk for recurrence than the routine histology does.

Sentinel lymph node biopsy in gynaecological cancers: the importance of micrometastases in cervical cancer

Lymph node metastases is a recognized prognostic factor in women with cervical cancer. However, there is a need for consensual histological definition of micrometastases in this indication which could give rise to a classification system similar to that used in breast cancer. We thus conducted a MEDLINE and EMBASE database analysis to evaluate the concept of micrometastases in cervical cancer. Retrospective studies place the incidence of micrometastasis between 1.5 and 15% depending on the technique used to evaluate lymph node status. Sentinel lymph node biopsy with serial sectioning and immunohistochemical analysis appears to be the most accurate micrometastases detection technique. The value of RT-PCR in micrometastases detection remains to be clarified by further studies. From a clinical view point, few data are available to support the prognostic relevance of micrometastases. However, case control and longitudinal studies have underlined the risk of recurrence in women with micrometastases, raising the issue of a revision of adjuvant therapy indications in this specific population.