The sentinel node in gynaecological malignancies

Value of sentinel node ultrastaging and pathologic techniques in tumoral detection

PURPOSE OF REVIEW

Sentinel lymph node assessment is an option for patients with clinically early-stage vulvar cancer, endometrial cancer, cervical cancer, and, more recently, ovarian cancer. However, although ultrastaging is mandatory as part of the node evaluation, universally accepted pathology protocols are lacking. This review focuses on the current evidence for the most relevant aspects of sentinel lymph node evaluation, as well as some controversial topics like frozen section or one-step nucleic acid amplification.

RECENT FINDINGS

The diagnostic accuracy of sentinel lymph node detection algorithms for patients with gynecologic neoplasms is high. However, the heterogeneity among the published studies and the absence of clear recommendations from most guidelines make it challenging to recommend one protocol over another. The minimum requirement from ultrastaging protocols (regarding the number of levels to be assessed, among others) to get the highest accuracy with a minor cost is unknown.

SUMMARY

Sentinel lymph node evaluation is now part of the surgical management for most early-stage gynecologic neoplasms. However, a universally accepted ultrastaging pathology protocol is lacking in literature and clinical practice. This gap requires significant effort from the gynecologic oncology and pathology community to be closed and then to allow advancements in surgical management for early-stage gynecologic tumors to go forward.

Imaging of Vaginal and Vulvar Malignancy

Vaginal and vulvar malignancies are rare gynecologic malignancies but can be associated with high morbidity and mortality if undiagnosed and untreated. Advanced imaging modalities such as MRI enable assessment of the local extent of disease and evaluation for regional or distant spread. Accurate identification and description of the primary lesion and sites of involvement as well as detection and localization of suspicious lymph nodes are critical in guiding appropriate management. Additionally, radiologists should be aware of potential mimickers on imaging and the differential diagnoses for vaginal and vulvar lesions.

Sentinel lymph node biopsy alone in the management of early cervical carcinoma

OBJECTIVE

Sentinel lymph node (SLN) biopsy aims to assess lymph node status with reduced surgical morbidity. The aim of the study was to determine the accuracy and safety of SLN biopsy in the management of early cervical carcinoma using a double technique (technetium-99m (Tc-99m) nanocolloid and methylene blue dye injection).

METHODS

This was a 10-year study from January 2009 to January 2019 that recruited 103 consecutive women undergoing surgery for early cervical carcinoma, FIGO 2009 stage IA1 (grade 3, and grade 2 with lymphovascular space invasion) to IB1 (<2 cm), at the West Kent Gynaecological Oncology Centre, Maidstone, UK. All patients were given the choice of pelvic node dissection and SLN mapping or SLN only. All patients elected to undergo SLN only. In total 97 patients had SLN mapping performed laparoscopically. We used the combined method (Tc-99m nanocolloid and/or methylene blue dye). All SLN routinely underwent ultrastaging.

RESULTS

At least one SLN was detected in all 103 patients, using at least one of the combined methods (Tc-99m nanocolloid or blue dye). Bilaterally SLN were removed in 85/103 women with an 83% bilateral detection rate. The median SLN count was 2.3 (range 1-6) nodes. Of 103 patients, 7 (6.7%) patients had lymph node involvement. There were no pelvic or para-aortic lymph node recurrences with a median follow-up of 53 (range 8-120) months. The specificity and negative predictive value of a negative SLN was 100%. None of our 103 patients reported lower extremity lymphedema.

CONCLUSION

In carefully selected patients with early cervical carcinoma, SLN biopsy alone appears to be a safe method for lymph node assessment of women undergoing surgical staging. Ultrastaging is an essential part of histologic examination of SLN.

Location of Sentinel Lymph Node in Cervical Carcinoma and Factors Associated With Unilateral Detection

OBJECTIVE

The aims of this study were to assess locality of the sentinel lymph node (SLN) in cervical carcinoma and examine factors affecting bilateral SLN detection.

METHODS

This was a retrospective review of SLN data (anatomical location, count and laterality) in patients with early-stage cervical cancer (International Federation of Gynecology and Obstetrics stage IA1 with lymphovascular space invasion to stage IIA) using intraoperative gamma probe and blue dye. The preoperative single-photon emission computed tomography with computed tomography was used to detect laterality, number of the SLNs, and rare locations. Patients were treated between January 2005 to January 2015 at the West Kent Gynaecological Oncology Centre, Maidstone Hospital, Maidstone, United Kingdom.

RESULTS

A total of 132 women were investigated. The most common SLN location was the external iliac (38.6%) followed by obturator (25.3%) and internal iliac (23.6%) regions. A small percentage was identified in presacral (1.4%) and para-aortic regions (0.7%). Older age (P = 0.01) and an elevated body mass index (P = 0.03) were associated with decreased SLN count by preoperative single-photon emission computed tomography with computed tomography, and only age affected SLN count by gamma probe (P = 0.01). Initial surgery, large loop excision of the transformation zone, or cone biopsy of the cervix had no effect on SLN count. There was no difference observed in bilateral detection with respect to surgical approach (open: n = 48/laparoscopic: n = 84). However, older age was independently associated with a decrease in bilateral SLN detection (P = 0.003). In these patients who underwent unilateral full pelvic lymphadenectomy, all the nonsentinel nodes were negative.

CONCLUSIONS

The majority of SLNs were located in the external iliac, obturator, and internal iliac regions. Both older age and an elevated body mass index were associated with a reduced SLN count. Unilateral detection of SLN was independently associated with older age, which may be due to sclerosis in the lymphatic vessels or reduced perfusion in the pelvis in these women. If no SLN is detected on one side, the consensus is to perform a full pelvic lymphadenectomy on that side of the pelvis.

Diagnosis and treatment of lymph node metastases in pediatric rhabdomyosarcoma in the Netherlands: a retrospective analysis

BACKGROUND

In pediatric rhabdomyosarcoma (RMS), evaluation of lymph node involvement (N1) is an important staging aspect, but difficult to assess. The aim of our study was to evaluate the assessment of lymph node infiltration and impact on outcome in N1 RMS patients.

METHODS

We identified 277 non-metastatic RMS patients diagnosed and treated between 1990 and 2008. Patients with recorded N1 disease were evaluated for their diagnostic procedures and outcome.

RESULTS

In 13.7% N1 status was reported. In 19 of 34 N1 patients, lymph node biopsies were performed for histologically confirmation. Different treatment modalities were used to treat lymph node metastases. In total 23 of 31 patients received local treatment of the node (11/23 RT, 4/23 surgery, and 8/23 both). All patients received chemotherapy. Lymph node relapse occurred in 7 of 31 patients who were treated with one or two modalities. Only 1 (14%) of 8 patients treated with three modalities relapsed. In N0 patients 10 (4.2%) of 239 had a regional lymph node relapse, and 9 of 10 died.

CONCLUSION

Lymph node metastases are an essential part of staging. Node positivity contributes to relapse of disease. Nodal relapse is also associated with a high mortality rate. These data imply that nodal assessment needs to be optimal and standardized for improved staging.

A prospective single-center study of sentinel lymph node detection in cervical carcinoma: is there a place in clinical practice?

OBJECTIVE

To establish the accuracy of sentinel lymph node (SLN) detection in early cervical cancer.

MATERIALS AND METHODS

Sentinel lymph node detection was performed prospectively over a 6-year period in 86 women undergoing surgery for cervical carcinoma by the combined method (Tc-99m and methylene blue dye). Further ultrastaging was performed on a subgroup of 26 patients who had benign SLNs on initial routine histological examination.

RESULTS

The SLN was detected in 84 (97.7%) of 86 women by the combined method. Blue dye uptake was not seen in 8 women (90.7%). Sentinel lymph nodes were detected bilaterally in 63 women (73.3%), and the external iliac region was the most common anatomic location (48.8%). The median SLN count was 3 nodes (range, 1-7). Of the 84 women with sentinel node detection, 65 also underwent bilateral pelvic lymph node dissection, and in none of these cases was a benign SLN associated with a malignant non-SLN (100% negative predictive value). The median non-SLN count for all patients was 19 nodes (range, 8-35). Eighteen patients underwent removal of the SLN without bilateral pelvic lymph node dissection. Nine women (10.5%) had positive lymph nodes on final histology. One patient had bulky pelvic nodes on preoperative imaging and underwent removal of the negative bulky malignant lymph nodes and a benign SLN on the contralateral side. This latter case confirms the unreliability of the SLN method with bulky nodes. The remaining 8 patients had positive SLNs with negative nonsentinel lymph nodes. Fifty-nine SLNs from 26 patients, which were benign on initial routine histology, underwent ultrastaging, but no further disease was identified. Four patients (5%) relapsed after a median follow-up of 28 months (range, 8-80 months).

CONCLUSION

Sentinel lymph node detection is an accurate and safe method in the assessment of nodal status in early cervical carcinoma.

[Current position of the sentinel lymph node procedure in endometrial cancer]

Lymph node status is a major prognostic element in endometrial cancer and affects the choice of adjuvant therapy. The sentinel lymph node (SLN) procedure is proposed as an alternative to lymphadenectomy. This review aims to assess its feasibility. To this end, 19 studies have been analysed. It appears that double detection (colorimetric and isotopic) is better than single detection, independent of injection site. Hysteroscopic injection is technically more difficult, yet can be done near the tumoral lesion. The cervical site does not accurately reflect the lymphatic drainage of the uterine body but is easier to access. SLN detection rate is notably identical between these two injections sites. Lomboaortic detection rate is lower for cervical injections than for endometrial ones. The myometrial site is also difficult to access (intraoperatively), due to same limitations as the hysteroscopic route, and can be deceiving (insufficient detection rate and high false-negative rate). The SLN allows for ultrastadification (micrometastases and isolated tumoral cells) with the development of new pathological techniques (serial sections and immunohistochemistry). Data on SLN in endometrial cancer is very heterogeneous in terms of methodology and populations studied. Despite being well-known, the SLN procedure in endometrial cancer remains in its feasibility stage. Its place in therapeutic strategies needs to be further explored and its potential benefit remains to be confirmed.

Use of contrast-enhanced ultrasound imaging to detect the first draining lymph node (FDLN) in a swine model: correlation of imaging findings with the distance from the injection site to the FDLN

OBJECTIVE

The purpose of this study was to investigate the use of contrast-enhanced ultrasound imaging (CEUS) to detect the first draining lymph node (FDLN) in a swine model and to determine whether the distance from the contrast agent injection site to the FDLN has any affect on the ability to detect contrast-enhanced FDLNs.

METHODS

Thirteen swine (25-32 kg) were anesthetized during examinations and euthanized afterward. In every swine, 1 mL of a sulfur hexafluoride microbubble ultrasound contrast agent was bilaterally injected subcutaneously below a mammilla. The examined distances varied from 6 to 36 cm. The contrast-enhanced lymphatic channels were visualized with low-mechanical index CEUS and mapped from the injection site to the FDLN. After CEUS was performed, blue dye was injected in the same locations as the contrast agent, and dye-guided surgery was used to localize the FDLNs. To ensure the lymph node detected with the blue dye technique was the same found with CEUS, it was scanned again to confirm contrast enhancement.

RESULTS

After 26 injections, 22 inguinal FDLNs were detected with CEUS and the blue dye technique. After 4 injections in 2 swine, contrast-filled lymphatic channels were identified with a course running toward the neck. In all cases but 1, the FDLNs received the contrast agent within 5 minutes.

CONCLUSIONS

In this swine model, it was possible to use CEUS to locate the FDLNs. In these preliminary experiments, the distances from the contrast agent injection site to the FDLN did not affect the ability to detect the contrast-enhanced FDLNs.

Micrometastases in cervical lymph nodes from patients with squamous carcinoma of the head and neck: should they be actively sought? Maybe

Techniques are now being developed, which allow ever smaller metastatic deposits in regional lymph nodes to be detected; the question is, should they be sought, or does their presence convey no additional information for treatment of head and neck carcinoma patients at this time? Preliminary findings have suggested that the presence of micrometastases may carry with it some prognostic information, and as a consequence, the search for micrometastases would, for the foreseeable future, appear to be a fertile ground for investigation. To bring some uniformity to this project, it is suggested that these definitions be adopted: a micrometastasis measures greater than 0.2 mm but less than 2.0 mm in diameter, and smaller deposits should be designated as isolated tumor cells, which, in turn, are subdivided into those isolated tumor cells detected by light microscopy, immunohistochemistry, or molecular methods. At this juncture, the import of such micrometastases remains in the realm of the clinical investigator--it remains an open question whether the identification of micrometastases (however they may ultimately come to be defined) will prove to have an impact on the care of head and neck cancer patients.

Current status of sentinel lymph node navigation surgery in breast and gastrointestinal tract

Sentinel lymph node biopsy (SLNB) has been developed as a new diagnostic and therapeutic modality in melanoma and breast cancer surgery. The purpose of the SLNB include preventing the operative morbidity and improving the pathologic stage by focusing on fewer lymph nodes using immunocytochemic and molecular technology has almost achieved in breast cancer surgery. The prognostic meaning of immunocytochemically detected micrometastases is also evaluating in the SLN and bone marrow aspirates of women with early-stage breast cancer. SLNB using available techniques have suggested that the lymphatic drainage of the gastrointestinal tract is much more complicated than other sites, skip metastasis being rather frequent because of an aberrant lymphatic drainage outside of the basin exist. At the moment, the available data does not justify reduced extent of lymphadenectomy, but provides strong evidence for an improvement in tumor staging on the basis of SLNB. Two large scale prospective multi-center trials concerning feasibility of gamma-probe and dye detection for gastric cancer are ongoing in Japan. Recent studies have shown favorable results for identification of SLN in esophageal cancer. CT lymphography with endoscopic mucosal injection of iopamidol was applicable for SLN navigation of superficial esophageal cancer. The aim of surgical treatment is complete resection of the tumor-infiltrated organ including the regional lymph nodes. Accurate detection of SLN can achieve a selection of a more sophisticated tailor made approach. The patient can make a individualized choice from a broader spectrum of therapeutic options including endoscopic, laparoscopic or laparoscopy-assisted surgery, modified radical surgery, and typical radical surgery with lymph node dissection. Ultrastaging by detecting micrometastasis at the molecular level and the choice of an adequate treatment improve the postoperative quality of life and survival. However these issues require further investigation.

Sentinel lymph nodes in early stage cervical cancer

OBJECTIVES

Lymph node status is the most important prognostic factor in cervical cancer. Sentinel lymph node (SLN) procedures have been purported to reduce peri- and postoperative morbidity and operative time.

METHODS

All patients with surgically managed clinical FIGO stage IA/B1 cervical cancer underwent SLN followed by pelvic lymphadenectomy with technetium+/-lymphazurin from April 2004 to April 2006. 0.1-0.2 mci of filtered sulfur colloid technetium was injected submucosally into 4 quadrants of the exocervix. Lymphazurin (4cc) was only used if technetium was unsuccessful in identifying bilateral sentinel lymph nodes. Serial microsections at 5 microm intervals were performed and stained intraoperatively. Complete pelvic node dissections were performed in all patients.

RESULTS

Forty-two patients underwent SLN, prior to full pelvic lymphadenectomy. Thirty-nine patients were included for the purposes of this study. The incidence in detecting at least one sentinel node was 98% per patient, and 85% per side. Identification of bilateral sentinel lymph nodes was successful in 28 cases (72%). The median number of SLN/side was 2. Three patients were found to have metastatic tumor to lymph nodes. No false negatives were identified. No adverse effects were noted.

CONCLUSIONS

SLN biopsy in cervical cancer is feasible to do, with a low false negative rate. We believe SLN should be evaluated per side and not per patient, that a pelvic lymphadenectomy is otherwise required. By following this protocol, the false negative rate can be minimized. The combined reported FN rate in the literature is 1.8%. If our definition is applied, the majority of reported false negative SLN is not actual false negatives.