Role of sentinel lymph node biopsy for gynecologic cancers

Future of sentinel node biopsy in ovarian cancer

PURPOSE OF REVIEW

The rationale on the use of sentinel lymph node (SLN) biopsy in the surgical staging of apparent early-stage ovarian cancer (OC) is supported by the fact that diagnostic and prognostic role of systematic staging lymphadenectomy has been determined but its therapeutic significance is still matter of controversy. Moreover, SLN biopsy represents an option to decrease intra- and postoperative morbidity. The present review aims to provide an overview on the current and future role of SLN in OC.

RECENT FINDINGS

Most recent evidence shows that the overall mean per patient SLN detection rate in case of indocyanine green (ICG) alone was 58.6% compared with 95% in case of ICG + technetium, and with 52.9% in case of technetium alone or in combination with blue dye ( P  < 0.001). Site of injection has been reported to be in both ovarian ligaments in majority of studies (utero-ovarian ligament and infundibulo-pelvic ligament), before or after ovarian mass removal, at time of primary or re-staging surgery and by minimally invasive or open approach. Cervical injection has been recently proposed to replace utero-ovarian injection. SLN detection rate in patients with confirmed ovarian malignancy varied across different studies ranging between 9.1% and 91.3% for the injection in the utero-ovarian ligament and migration to pelvic lymph nodes and between 27.3% and 100% for the injection in the infundibulo-pelvic ligament and migration to para-aortic lymph nodes. No intra- or postoperative complication could be attributed directly to SLN biopsy. The sensitivity and the accuracy of SLN in detecting lymphatic metastasis ranged between 73.3-100% and 96-100%, respectively. In up to 40% of positive SLNs, largest metastatic deposit was classified as micro-metastasis or isolated tumor cells, which would have been missed without ultrastaging protocol.

SUMMARY

SLN biopsy represents a promising tool to assess lymph node status in apparent early-stage OC. The type and volume of injected tracer need to be considered as appear to affect SLN detection rate. Ultrastaging protocol is essential to detect low volume metastasis. Sensitivity and accuracy of SLN biopsy are encouraging, providing tracer injection in both uterine and ovarian ligaments.

Benefits of the Enhanced Recovery After Surgery (ERAS) Pathway With Quadratus Lumborum Blocks for Minimally Invasive Gynecologic Surgery Patients: A Retrospective Cohort Study

STUDY OBJECTIVE

This study aimed to determine the effect of the implementation of the Enhanced Recovery After Surgery (ERAS) protocol among patients receiving minimally invasive gynecologic surgery.

DESIGN AND SETTING

This retrospective cohort study was performed in a tertiary care hospital.

PATIENTS

A total of 328 females who underwent minimally invasive gynecologic surgeries requiring at least one overnight stay at Keck Hospital of University of Southern California (USC), California, USA, from 2016 to 2020 were included in this study.

INTERVENTIONS

The institutional ERAS protocol was implemented in late 2018. A total of 186 patients from 2016 to 2018 prior to the implementation were compared to 142 patients from 2018 to 2020 after the implementation. Intraoperatively, the ERAS group received a multimodal analgesic regimen (including bilateral quadratus lumborum (QL) blocks) and postoperative care geared toward a satisfactory, safe, and expeditious discharge.

MEASUREMENTS AND MAIN RESULTS

The two groups were similar in demographics, except for the shorter surgical time noted in the ERAS group. The median opioid use was significantly less among the ERAS patients compared with the non-ERAS patients on postoperative day 1 (7.5 vs. 14.3 mg; p<0.001) and throughout the hospital stay (17.4 vs. 36.2 mg; p<0.001). The ERAS group also had a shorter median hospital length of stay compared to the non-ERAS group (p<0.01). Among patients with a malignant diagnosis, patients in the ERAS group had significantly less postoperative day 1 and total opioid use and a shorter hospital stay (p<0.01). Within the ERAS group, 20% of the patients did not end up receiving a QL block. Opioid use and length of stay were similar between patients who did and did not receive the QL block.

CONCLUSIONS

The ERAS pathway was associated with a reduction in opioid use postoperatively and a shorter length of hospital stay after minimally invasive gynecologic surgery. There was a more significant decrease in opioid use and hospital length of stay for patients with malignant diagnoses compared to patients with benign diagnoses. Further research can be done to fully delineate the effect of QL blocks in ERAS protocols.

A Drop-in Gamma Probe for Minimally Invasive Sentinel Lymph Node Dissection in Prostate Cancer: Preclinical Evaluation and Interim Results From a Multicenter Clinical Trial

PURPOSE

This study evaluated the performance of a drop-in gamma probe for prostate cancer (PCa) sentinel lymph node dissection (SLND) in a pelvic phantom, porcine model, and in PCa patients as part of an ongoing prospective multicenter clinical trial.

METHODS

Two design variants of the drop-in gamma probe (SENSEI; Lightpoint Medical Ltd) were assessed in the pelvic phantom, and the preferred design was evaluated in a porcine model with clinically representative volumes and 99mTc activities. In the clinical trial, radical prostatectomy, SLND, and extended pelvic lymph node dissection were performed the day after 99mTc-nanocolloid injection and imaging. Sentinel lymph nodes (SLNs) were detected with the drop-in probe and a rigid laparoscopic gamma probe (RLGP). An interim analysis was performed after 10 patients were recruited.

RESULTS

The narrow field of view probe design outperformed the wide field of view design in the pelvic phantom (detection rate, 100% vs 50%). In the porcine model, all activity concentrations could be successfully detected. The drop-in gamma probe successfully detected SLNs in all 10 patients (detection rate, 100%). Two of the SLNs identified by the drop-in gamma probe could not be found with the RLGP. No false-negative cases and no adverse events related to the SLND procedure or the drop-in gamma probe occurred.

CONCLUSION

The drop-in gamma probe meets the usability and performance requirements for SLND in PCa and provides performance advantages over the RLGP. The final clinical study results will confirm the performance of the technique across multiple sites.

Technetium Tc 99m tilmanocept fails to detect sentinel lymph nodes in endometrial cancer

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Indocyanine green (ICG) is effective for sentinel lymph node detection (SLN) in endometrial cancer.

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Technetium Tc 99m tilmanocept is FDA-approved for SLN detection in breast cancer, melanoma, and head and neck cancers.

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We aimed to determine the SLN detection rate in endometrial cancer with concurrent technetium Tc 99m tilmanocept and ICG use.

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Technetium Tc 99m tilmanocept failed to detect sentinel lymph nodes in endometrial cancer patients in our prospective study.

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ICG alone remains a standard SLN detection technique in endometrial cancer, while limiting burdens from a dual agent.

Background

Technetium Tc 99m tilmanocept is a synthetic radiotracer specifically designed for sentinel lymph node (SLN) mapping that has been FDA-approved in breast cancer, melanoma, and head and neck cancer. No published studies exist for the use of this radiotracer in endometrial cancer.

Objective

The primary objective was to determine the detection rate of bilateral SLNs in endometrial cancer with the concurrent use of technetium Tc 99m tilmanocept and ICG.

Methods

An open-label, single cohort, prospective feasibility study was conducted with participants receiving preoperative cervical injections of technetium Tc 99m tilmanocept followed by subsequent imaging and SPECT/CT. Intraoperative ICG injections were administered for all patients with near-infrared imaging used to visualize lymphatic vessels and nodes. A laparoscopic gamma counter was used to detect radioactive SLN intraoperatively.

Results

All six evaluated patients had FIGO grade 1 or 2 endometrioid histology. Stage IA/IB were in 33% and 66% of patients, respectively. Tilmanocept did not map any SLN in the first six patients but instead showed retention of the tracer in the cervical stroma, leading to study discontinuation for futility. ICG mapped bilateral SLN in all patients with the most common location being the external iliac region, followed by the obturator and common iliac areas. All patients had CD206 positive staining throughout the full wall thickness of ectocervix, transformation zone, endocervix, and lymphatic vessels. No patients experienced adverse events.

Conclusion

Technetium Tc 99m tilmanocept did not detect SLN in early stage endometrial cancers and is unlikely to improve bilateral detection rate compared to ICG alone. ICG remains a standard technique for SLN detection in low stage, low grade endometrial cancer.

Management of Early-Stage Vulvar Cancer

Simple Summary

Vulvar cancer is a rare gynecological malignancy that affects mainly postmenopausal women. Recently, however, an alarming increase in the rates among young women has been observed due to human papillomavirus infection. The standard treatment for vulvar cancer is surgery with or without radiotherapy as adjuvant treatment. In recent decades, sentinel lymph node biopsy has been included as part of the surgical treatment. Thus, our objective was to review and discuss the advances found in the literature about early-stage vulvar cancer. For this, we searched PubMed for publications in the English language. Relevant articles, such as the GROINS-V studies, and the GOG protocols, are presented in this review exhibiting the evolution of early-stage vulvar cancer treatment and the decrease in surgical morbidity rates.

Abstract

Vulvar cancer is a rare gynecological malignancy since it represents 4% of all cancers of the female genital tract. The most common histological type is squamous cell carcinoma (90%). This type can be classified into two clinicopathological subtypes according to the etiology. The first subtype is associated with persistent human papillomavirus infection and is usually diagnosed in younger women. The second subtype is associated with lichen sclerosus condition, and in most cases is diagnosed in postmenopausal women. Currently, an increase in first subtype cases has been observed, which raised the concern about associated mortality and treatment morbidity among young women. Vulvar cancer treatment depends on histopathology grade and staging, but surgery with or without radiotherapy as adjuvant treatment is considered the gold standard. In recent decades, sentinel lymph node biopsy has been incorporated as part of the treatment. Therefore, we sought to review and discuss the advances documented in the literature about vulvar cancer focusing on the treatment of early-stage disease. Relevant articles, such as the GROINS-V studies and the GOG protocols, are presented in this review. Additionally, we discuss key points such as the evolution of treatment from invasive surgery with high morbidity, to more conservative approaches without compromising oncologic safety; the role of sentinel lymph node mapping in the initial staging, since it reduces the complications caused by inguinofemoral lymphadenectomy; the recurrences rates, since local recurrence is common and curable, however, groin-associated, or distant recurrences have a poor prognosis; and, finally, the long-term follow-up that is essential for all patients.

Recent advances in aggregation-induced emission luminogens in photoacoustic imaging

Photoacoustic imaging (PAI) is a rapidly emerging modality in biomedical research with the advantages of noncontact operation, high optical resolution, and deep penetration. Great efforts and progress in the development of PAI agents with improved imaging resolution and sensitivity have been made over the past 2 decades. Among them, organic agents are the most promising candidates for preclinical/clinical applications due to their outstanding in vivo properties and facile biofunctionalities. Motivated by the unique properties of aggregation-induced emission (AIE) luminogens (AIEgens), various optical probes have been developed for bioanalyte detection, multimodal bioimaging, photodynamic/photothermal therapy, and imaging-guided therapeutics. In particular, AIE-active contrast agents have been demonstrated in PAI applications with excellent performance in imaging resolution and tissue permeability in vivo. This paper presents a brief overview of recent progress in AIE-based agents in the field of photoacoustic imaging. In particular, we focus on the basic concepts, data sorting and comparison, developing trends, and perspectives of photoacoustic imaging. Through numerous typical examples, the way each system realizes the desired photoacoustic performance in various biomedical applications is clearly illustrated. We believe that AIE-based PAI agents would be promising multifunctional theranostic platforms in clinical fields and will facilitate significant advancements in this research topic.

Systematic Pelvic and Para-Aortic Lymphadenectomy During Fertility-Sparing Surgery in Patients With Early-Stage Epithelial Ovarian Cancer: A Retrospective Study

Objective

The implication of pelvic and para-aortic lymphadenectomy in surgical staging of early-stage epithelial ovarian cancer (eEOC) is still debated. Limited data are available about systematic lymphadenectomy during fertility-sparing surgery (FSS) in patients with eEOC.

Methods

The medical records of 38 patients with FIGO stage I EOC and below 40 years who underwent FSS at our hospital between January 2003 and December 2018 were retrospectively reviewed.

Results

Among them, 18 patients (47.4%) underwent comprehensive lymphadenectomy, 11 patients (28.9%) underwent lymph node sampling, and 9 patients (23.7%) did not undergo lymphadenectomy. There was no statically significant difference in age, histology, grade, surgical approach, chemotherapy, and gestation among the three groups. With a median follow-up of 52.5 months (range: 24-153), three patients (7.9%) with FIGO stage IC EOC developed tumor recurrence. In these patients, progress-free survival (PFS) was 92.1%, and overall survival (OS) was 94.7%. No significant difference in the OS. Three patients had among all the patients, 15 patients (39.5%) had gestation after treatment, and 23 patients (60.5%) did not have gestation after treatment.

Conclusion

The number of lymph nodes removed did not significantly affect survival eEOC with FSS. Systematic pelvic and para-aortic lymphadenectomy could not be performed for mucious eEOC patients with FSS if intraoperative freezing in confirmed and no suspicious lymph nodes are found. A better understanding of sentinel lymph node biopsy may help to identify whether the patient requires FSS.

The Feasibility of Sentinel Lymph-Node, Mapped with Indocyanine Green, Biopsy in Endometrial Cancer Patients: A Prospective Study

Background and objectives. Systematic pelvic lymphadenectomy (LND) is an essential part of lymph-node status evaluation in endometrial cancer (EC) patients to tailor the adjuvant treatment. However, it is associated with the post-operative lymphatic complications and does not improve the outcomes of the disease. Indocyanine green (ICG) mapped sentinel lymph-node biopsy (SLB) has recently been introduced into the clinical practice as an alternative for the surgical lymph-node evaluation in EC patients with the potential to decrease LND related complications. The aim of our study was to evaluate the feasibility of ICG mapped SLB in low, intermediate, and high-risk EC patients in a center with no previous experience on endoscopic SLB procedure. Materials and Methods: The prospective study was performed. 170 patients with histologically confirmed EC were included. Sentinel lymph-nodes (SLs) were mapped with ICG dye and removed ahead of the total laparoscopic hysterectomy. Low-risk patients received only SLB, while SLB and LND were performed for intermediate and high-risk patients. Results: The overall detection rate of SLs was 88.8%. Bilateral mapping was achieved in 68.2% of the patients. The overall detection rate for low-risk patients was 93.7%, 85.0% for the intermediate-risk group, and 100% for high-risk patients (p = 0.232). The most common anatomical sites of SLs were the external iliac (45.8% on the right and 46.6% on the left) and obturator regions (20.9% and 25.6%, respectively). Positive lymph-nodes were found in 8 (4.7%) patients. The sensitivity of SLB was 75.0% and negative predictive value (NPV)—97.2%. Conclusions: Even in the center with no previous experience, sentinel lymph-node biopsy using ICG mapping is feasible. However, the favorable outcomes might be associated with the learning process of newly established method.

Cervical versus utero-ovarian ligament injection of the tracer for the pelvic sentinel lymph node mapping in gynecologic oncology: a prospective observational study

OBJECTIVE

In gynecologic oncology, the consolidated injection site for the pelvic sentinel lymph node mapping is the cervix. However, in apparent early-stage ovarian cancer, current trials map the pelvic area injecting the tracers in the utero-ovarian ligament. A different injection site is proposed based on a possible different lymphatic ovarian drainage through the utero-ovarian ligament and uterus and consequently a different pelvic sentinel lymph node mapping than the cervix; however, this was never proven. On that basis, this study aimed to investigate whether injecting the tracer in the utero-ovarian ligament map the same or a different pelvic sentinel lymph node than the cervix.

DESIGN

Prospective observational study.

METHODS

All consecutive women undergoing primary surgery for gynecologic malignancy with planned pelvic sentinel lymph node mapping were enrolled. The cervical injection was performed at 3 and 9 o'clock injecting indocyanine green. Bilateral utero-ovarian ligament injection was performed injecting methylene blue. The probability of detecting the same sentinel lymph node (concordance rate) and the probability of detecting a different sentinel lymph node (discordance rate) in each hemipelvis were compared using the McNemar's exact test.

RESULTS

Out of 36 hemipelvis (18 patients), the overall detection rate with cervical indocyanine green injection was 86.1% (31/36) versus 52.8% (19/36) with utero-ovarian ligament methylene blue injection (p=0.0004). Indocyanine green and methylene blue identified the same sentinel lymph node in all hemipelvis when sentinel lymph node mapping was obtained by both dyes (19/19; concordance rate 100%). No different or additional sentinel lymph nodes were identified by one of the two dyes (0/19; discordance rate 0%). The probability of detecting the same pelvic sentinel lymph node by the two injections sites was significantly higher than the probability of detecting a different pelvic sentinel lymph node (p<0.0001).

LIMITATIONS

The use of two different dyes with known different sentinel lymph node mapping performance impedes to evaluate differences in detection rate attributable to the two injection sites, limiting the comparison only in hemipelvis in which both dyes identified a sentinel lymph node.

CONCLUSIONS

Cervix and utero-ovarian ligament are two sites for the tracer injection that have a higher probability of detecting the same than a different pelvic sentinel lymph node. Given the higher technical challenge in performing the utero-ovarian ligament injection, these results suggest that the injection of the tracer into the cervix could be a more reliable alternative for the pelvic sentinel lymph node mapping in ovarian cancer.