Sentinel lymph node biopsy with cervical injection of indocyanine green in apparent early-stage endometrial cancer: predictors of unsuccessful mapping

Sentinel Lymph Node Assessment in Endometrial Cancer: A Review

As the number of patients diagnosed with endometrial cancer rises, so does the number of patients who undergo surgical treatment, consisting of radical hysterectomy, bilateral salpingo-oophorectomy, and bilateral pelvic lymphadenectomy or lymph node sampling. The latter entail intra- and post-surgical complications, such as lymphedema and increased intra-operative bleeding, which often outweigh their benefits. Sentinel Lymph Node (SLN) sampling is now common practice in surgical management of breast cancer, as it provides important information about the disease without jeopardizing surgical radicality and patient outcomes. While this technique has also been shown to be feasible in patients with endometrial cancer, there is little consensus on several aspects, such as tracer injection volume and site, pathological ultrastaging, and result interpretation. The aim of this review is to analyze the current literature on SLN assessment in order to help standardize the procedure.

Indocyanine green in gynecologic surgery: Where do we stand? A literature review and meta-analysis

The main objective of this study was to review and perform a meta-analysis of current literature on the use of indocyanine green for sentinel lymph node detection in pelvic gynecologic cancer. We included all studies focusing on indications and procedures associated with the use of ICG in gynecologic surgery and available on the Medline and Pubmed database. For the meta-analysis, random effect models were used for estimation of the 95 % detection rate and 95 % confidence interval, and stratified analyses by cancer type, concentration and localization of injection were performed. A total of 147 articles were included, of which 91 were studied in a meta-analysis. Results concerning detection rate by indocyanine green injection site were found to be 95.1 % and 97.3 % respectively for intracervical injection in 2 or 4 quadrants, and 77.0 % and 94.8 % for hysteroscopic and intradermal injection respectively. Results concerning detection rate by cancer type were 95.8 %, 95.2 %, 94.7 % and 95.7 % respectively for cervical, endometrial, vulvar and endometrial/cervical cancers. Finally, the results concerning detection rate by indocyanine green concentration were 91.2 %, 95.7 %, 96.7 % and 97.7 % for concentrations of <1.25 mg/ml, 1.25 mg/ml, 2.5 mg/ml and 5 mg/ml respectively. In conclusion, indocyanine green is shown to allow highlighting of sentinel lymph nodes with good reliability with an overall indocyanine green detection rate of 95.5 %. Our literature review revealed that indocyanine green feasibility has also been demonstrated in several surgical contexts, notably for reconstructive surgery and detection of endometriosis.

Assessment of sentinel Lymph node mapping with different volumes of Indocyanine green in early-stage ENdometrial cancer: the ALIEN study

OBJECTIVE

To evaluate the impact of different volumes of indocyanine green (ICG) on the detection rate and bilateral mapping of sentinel lymph nodes in patients with apparent uterine-confined endometrial cancer.

METHODS

All patients who underwent surgical staging with sentinel node mapping in six reference centers were included. Two different protocols of ICG intracervical injection were used: (1) 2 mL group: total volume of 2 mL injected superficially; (2) 4 mL group: total volume of 4 mL, 2 mL deeply and 2 mL superficially. Logistic regression was used to analyze factors that could influence dye migration and detection rates. A sensitivity analysis was carried out to determine how independent variables could affect the sentinel node detection rate.

RESULTS

Of 442 eligible patients, 352 were analyzed (172 in the 2 mL group and 180 in the 4 mL group). The bilateral detection rates of the 2 mL and 4 mL groups were 84.9% and 86.1%, respectively (p=0.76). The overall detection rate was higher with a volume of 4 mL than with 2 mL (97.8% vs 92.4%, respectively; p=0.024). In the univariate analysis the rate of bilateral mapping fell from 87.5% to 73.5% when the International Federation of Gynecology and Obstetrics (FIGO) 2009 tumor stage was >IB (p=0.018). In the multivariate analysis, for both overall and bilateral detection rates a statistically significant difference emerged for the volume of ICG injected and FIGO 2009 stage >IB. Increasing body mass index was associated with worse overall detection rates on univariate analysis (p=0.0006), and significantly decreased from 97% to 91% when the body mass index exceeded 30 kg/m2 (p=0.05).

CONCLUSIONS

In patients with early-stage endometrial cancer, a volume of 2 mL ICG does not seem to compromise the bilateral detection of sentinel lymph nodes. In women with obesity and FIGO 2009 stage >IB, a 4 mL injection should be preferred.

Impact of comorbidities and extent of lymphadenectomy on quality of life in endometrial cancer patients treated with minimally invasive surgery in the era of sentinel lymph nodes

OBJECTIVE

To identify predictors of quality of life (QoL) among patients who undergo surgical staging with sentinel lymph node (SLN) biopsy or lymphadenectomy for endometrial cancer.

METHODS

Patients who underwent minimally invasive surgery for primary endometrial cancer at the Mayo Clinic from October 2013 to June 2016 were mailed a 30-item QoL in Cancer survey (QLQ-C30) and a validated 13-item lower extremity lymphedema screening questionnaire. Patients who answered <50% of the items or had a pre-operative history of lymphedema were excluded. Multivariable linear regression models were fit to evaluate predictors of QoL using inverse-probability of treatment weighting to adjust for differences at the time of the surgery between the lymphadenectomy and SLN groups.

RESULTS

The 221 patients included in the analysis were stratified into two groups: patients who underwent (1) bilateral lymphadenectomy as 'backup' after SLN mapping (lymphadenectomy group; n=101) or (2) SLN removal with or without side-specific lymphadenectomy (SLN group; n=120). On multivariable analysis, obesity, lower extremity lymphedema, and kidney disease had significant (p<0.05) and clinically meaningful negative impacts on global QoL. Declines in average adjusted global QoL scores were marked (19.7 points lower) in patients with BMI ≥40 kg/m2 and lower extremity lymphedema compared with non-obese patients without lower extremity lymphedema. In contrast, there was only a 2.9 point difference in the adjusted average global QoL score between the SLN and lymphadenectomy groups.

CONCLUSIONS

Lower extremity lymphedema coupled with obesity predicts poorer QoL in patients who undergo surgical staging for endometrial cancer. In this population, reduction of lower extremity lymphedema by performing SLN instead of lymphadenectomy and earlier targeted interventions may improve patients' QoL. Future research focusing on targeted interventions is needed.

Predictive factors of sentinel lymph node failed mapping in endometrial carcinoma patients: a systematic review and meta-analysis

OBJECTIVE

In endometrial carcinoma patients, sentinel lymph node bilateral mapping fails in 20-25% of cases, with several factors affecting the likelihood of detection. However, pooled data about predictive factors of failure are lacking. The aim of this systematic review and meta-analysis was to assess the predictive factors of sentinel lymph node failed mapping in endometrial cancer patients undergoing sentinel lymph node biopsy.

METHODS

A systematic review and a meta-analysis was performed searching all studies assessing predictive factors of sentinel lymph node failed mapping in apparent uterine-confined endometrial cancer patients undergoing sentinel lymph node biopsy through the cervical injection of indocyanine green. The associations between sentinel lymph node failed mapping and predictive factors of failure were assessed, calculating the odds ratio (OR) with 95% confidence intervals.

RESULTS

Six studies with a total of 1345 patients were included. Compared with patients with sentinel lymph node bilateral successful mapping, patients with sentinel lymph node failed mapping showed: OR 1.39 (p=0.41) for body mass index >30 kg/m²; OR 1.72 (p=0.24) for menopausal status; OR 1.19 (p=0.74) for adenomyosis; OR 0.86 (p=0.55) for prior pelvic surgery; OR 2.38 (p=0.26) for prior cervical surgery; OR 0.96 (p=0.89) for prior Cesarean section; OR 1.39 (p=0.70) for lysis of adhesions during surgery before sentinel lymph node biopsy; OR 1.77 (p=0.02) for indocyanine green dose <3 mL; OR 1.28 (p=0.31) for deep myometrial invasion; OR 1.21 (p=0.42) for International Federation of Gynecology and Obstetrics (FIGO) grade 3; OR 1.89 (p=0.01) for FIGO stages III-IV; OR 1.62 (p=0.07) for non-endometrioid histotype; OR 1.29 (p=0.25) for lymph-vascular space invasion; OR 4.11 (p<0.0001) for enlarged lymph nodes; and OR 1.71 (p=0.022) for lymph node involvement.

CONCLUSION

Indocyanine green dose <3 mL, FIGO stage III-IV, enlarged lymph nodes, and lymph node involvement are predictive factors of sentinel lymph node failed mapping in endometrial cancer patients.

Laparoscopic sentinel lymph node mapping with indocyanine green in endometrial cancer: surgeon's learning curve (cumulative sum analysis)

OBJECTIVES

To evaluate surgeons' learning curves for laparoscopic sentinel lymph node biopsy in endometrial cancer.

METHODS

A prospective observational study was performed at the Oncogynecology Center, Lithuanian University of Health Sciences Hospital, from March 2018 to October 2022. Participating surgeons had no previous experience of laparoscopic sentinel lymph node biopsy with indocyanine green tracer. Cumulative sum analysis was used to create learning curves for the performance of eight surgeons, based on a specific result over a time period. Two different cumulative sum plots were made for each surgeon: successful bilateral sentinel lymph node mapping and removal of sentinel lymph node specimens containing actual lymphatic tissue.

RESULTS

190 patients were included. The overall rate of sentinel lymph node mapping was 89.5%: successful bilateral mapping was achieved in 134 (70.5%) patients, while in 36 (19%) patients sentinel lymph nodes were mapped unilaterally. The bilateral detection rate significantly improved in later study periods (from 59.3% in the first year to 85.0% in the last year; p=0.03). Analysis of the performance of the surgeons for bilateral sentinel lymph node mapping showed that the cumulative sum plot crossed the H₀ limit line after 13 consecutive successful bilateral sentinel lymph node biopsies, indicating an acceptable level of competence to achieve the bilateral detection rate of at least 75%. This was accomplished by only one surgeon after 30 surgeries. Analysis of the performance of the surgeons for identification and removal of specimens containing histologically confirmed lymphatic tissue showed that the cumulative sum plots crossed the H₀ limit line after six consecutive successful sentinel lymph node removals. This was accomplished by most of the surgeons (5 of 8).

CONCLUSION

At least 30 procedures of indocyanine green traced laparoscopic sentinel lymph node biopsy were needed to reach an acceptable level of competence for a bilateral sentinel lymph node detection rate of at least 75%.

TRIAL REGISTRATION NUMBER

ACTRN12619000979156.

Characteristics of systematic lymph node dissection and influencing factors of sentinel lymph node biopsy using carbon nanoparticles in endometrial carcinoma: a single-center study

BACKGROUND

Carbon nanoparticles (CNPs) are a new tracer for lymph node mapping, which can quickly reach and develop lymph nodes through a lymphatic network. This research investigated the characteristics of systematic lymph node dissection and sentinel lymph node biopsy mapped with CNPs in endometrial carcinoma.

METHODS

We first applied CNPs to systematic lymph node dissection in 18 endometrial carcinoma patients as the study group and another 18 endometrial carcinoma patients who were not injected with anything served as the control group. Then, we applied CNPs to sentinel lymph nodes biopsy in 54 endometrial carcinoma patients. All 54 patients received systematic lymph node dissection after sentinel lymph node biopsy. The detection rate, sensitivity, specificity, and accuracy of systematic lymph node dissection and sentinel lymph node biopsy by CNPs were respectively analyzed. A nomogram model for predicting the success of sentinel lymph node mapping was established.

RESULTS

The average number of lymph nodes removed in the CNP-labeled study group was higher than that in the control group (p<0.001). CNPs improved the number of lymph nodes with a diameter ≤ 0.5cm. The detection rate, sensitivity, specificity, and accuracy of sentinel lymph nodes biopsy by CNPs for endometrial carcinoma were 70.4%, 100%, 100%, and 100%, respectively. The nomogram model included factors of long menopause time, cervical cyst, and hard cervical texture, and the area of ROC curve was 0.816.

CONCLUSIONS

CNPs improve the detection rate of small lymph nodes. CNPs can trace sentinel lymph nodes in evaluating lymph node metastasis in endometrial carcinoma.

Clinical factors associated with failed sentinel lymph node mapping in endometrial cancer

Objective

Sentinel lymph node (SLN) mapping is a highly accurate surgical technique for detecting metastases in endometrial cancer. The objective of this study was to identify clinical factors associated with failed mapping.

Methods

All patients with endometrial cancer undergoing minimally-invasive staging and planned SLN biopsy from 1/1/2017 to 12/31/2020 at a single institution were identified retrospectively. Demographic, clinicopathologic and treatment data were obtained. Data were compared using descriptive statistics. Univariate and multivariable logistic regression were performed to identify predictors of failed mapping.

Results

819 patients were identified with a mean age of 64.6 years (range 26-93) and mean BMI of 35.6 kg/m² (range 18-68). Most (88.5 %, 725/819) had early-stage disease and endometrioid histology (82.3 %, 674/819). A majority (74.2 %, 608/819) had successful bilateral mapping, and 54 (6.6 %) had unsuccessful bilateral mapping. Increasing BMI was significantly associated with unsuccessful bilateral mapping: patients with BMI > 30 were more likely to have unsuccessful SLN mapping (p = 0.033). Among patients with known lymph node status (799/819), patients with macrometastases and micrometastases were more likely to have failed bilateral mapping compared to those with negative SLNs or isolated tumor cells (p = 0.013). On multivariable analysis, higher BMI and histology were associated with failed bilateral mapping (OR = 1.023, 95 % CI (1.005, 1.041) and OR = 1.678, 95 % CI (1.177, 2.394), respectively).

Conclusion

SLN mapping has a high success in patients undergoing minimally-invasive surgical staging for endometrial cancer. Increasing BMI, high risk histology, and lymph node metastases are risk factors for failed mapping.

Pathological processing of sentinel lymph nodes in endometrial carcinoma - routine aspects of grossing, ultra-staging, and surgico-pathological parameters in a series of 833 lymph nodes

Sentinel lymph nodes are widely accepted in the treatment of endometrial carcinoma. Whereas surgical aspects are well studied, the pathological work-up in terms of grossing, frozen section, and the so-called ultra-staging is still a matter of debate. This results in conflicting national or center-based recommendations. In a series of consecutive 833 sentinel lymph nodes from 206 patients in endometrial carcinomas, we compared three different grossing techniques and the use of frozen section in terms of anatomy, detection rates, and survival. In total, 42 macro-metastases, 6 micro-metastases, and 25 nodes with isolated tumor cells were found. Lymph nodes affected at least with micro-metastasis were about 0.5cm enlarged. Detection rates in lamellation technique increased with a step of 5.9% to 8.3% in comparison to bi-valved or complete embedding. The lamellation technique presented with a slight beneficial prognosis in pN0 subgroup (OS, p=0.05), which besides size effects might be attributed to trimming loss. In frozen section, this effect was less pronounced than expected (OS, p=0.56). Ultra-staging only revealed additional micro-metastases and isolated tumor cells. Exclusively, macro-metastases showed poor survival (p<0.001). In multivariate analysis, T-stage, subtype, and lympho-vascular invasion status outperformed this staging parameter significantly. Grossing of sentinel lymph nodes is the most essential step with evidence to prefer lamellation in 2 mm steps. Step sectioning should consider widely spaced protocols to exclude macro-metastases. Frozen sections might add value to the intra-operative assessment of endometrial carcinoma in selected cases. The excellent biological behavior of cases with isolated tumor cells might question the routine application of pan-cytokeratin as ultra-staging method.

Surgical and oncological outcomes of sentinel lymph node sampling in elderly patients with intermediate to high-risk endometrial carcinoma

OBJECTIVE

We aimed to evaluate the surgical and oncological outcomes of elderly patients with intermediate to high-risk endometrial cancer undergoing staging with sentinel lymph node (SLN) sampling and pelvic lymphadenectomy.

METHODS

We conducted a retrospective study of elderly (>65-year-old) patients diagnosed with endometrial cancer between December 2007 and August 2017. These patients had been treated at a single center in Montreal, Canada. We compared the surgical and oncological outcomes of three cohorts undergoing surgical staging in non-overlapping eras: 1) lymphadenectomy, 2) lymphadenectomy and SLN sampling, 3) SLN sampling alone. Using life tables, Kaplan-Meier survival curves and log-rank tests, we analyzed 2-year progression-free survival, overall survival, and disease-specific survival.

RESULTS

Our study included 278 patients with a median age of 73 years (range; 65-91): 84 (30.2%) underwent lymphadenectomy, 120 (43.2%) underwent SLN sampling with lymphadenectomy, and 74 (26.6%) had SLN sampling alone. The SLN sampling alone group had shorter operative times with a median duration of 199 minutes (range, 75-393) compared with 231 (range, 125-403) and 229 (range, 151-440) minutes in the SLN sampling with lymphadenectomy and lymphadenectomy cohorts; respectively (p<0.001). The SLN sampling alone group also had lower estimated blood loss with a median loss of 20 mL (range, 5-150) vs 25 mL (range, 5-800) and 40 mL (range, 5-400) in the SLN sampling with lymphadenectomy and lymphadenectomy cohorts, respectively (p=0.002). The 2 year overall survival and progression-free survival were not significantly different between the three groups (p=0.45, p=0.51, respectively). On multivariable analysis after adjusting for age, American Society of Anesthesiologists (ASA) score, stage, grade, and lymphovascular space invasion, adding SLN sampling was associated with better overall survival, (HR 0.2, CI [0.1 to 0.6], p=0.006) and progression-free survival (HR 0.5, CI [0.1 to 1.0], p=0.05).

CONCLUSION

Sentinel lymph node-based surgical staging is feasible and associated with better surgical outcomes and comparable oncological outcomes in elderly patients with intermediate and high-risk endometrial cancer.

Sentinel Lymph Node Sampling in Robot-Assisted Staging of Endometrial Cancer

OBJECTIVE

Sentinel lymph node (SLN) sampling in endometrial cancer staging has become an acceptable standard. Indocyanine green dye injected into the cervix and detected by near-infrared light is technically simple and sensitive. We aimed to evaluate SLN sampling in robot-assisted surgical staging of endometrial cancer at a university-affiliated teaching hospital.

METHODS

A retrospective chart review, from January 2016 to December 2017, of patients who underwent robot-assisted surgical staging with cervical injection of indocyanine green dye detected by near-infrared light. The map rate, sensitivity, false negatives, and negative predictive value were calculated.

RESULTS

A total of 105 charts were reviewed; 79 patients met inclusion criteria. The mean age was 65 (range 38-93) and the mean body mass index was 33.3 (range 16-49). Most patients (72.2%) had stage I disease and grade 1 or 2 histology (77.1%). Eight (10.1%) patients had lymph node metastasis. Seventy-two (91.1%) patients had positive mapping to at least 1 SLN. Sixty-two (78.5%) patients had bilateral mapping. Forty-four patients had concurrent pelvic ± para-aortic lymph node dissection and were included in the sensitivity analysis. Five of 44 cases had LN metastasis. The sensitivity was 80%, and the negative predictive value of SLN sampling was 97.5%.

CONCLUSIONS

SLN mapping and sampling at a university-affiliated teaching hospital have comparable map rate, sensitivity, and negative predictive value as demonstrated in multiple trials. The technique has the potential to standardize endometrial cancer staging across different practice settings.

Utility of indocyanine green as a single tracer for sentinel node biopsy in endometrial cancer

AIM

Our study aims to investigate the safety and effectiveness of sentinel lymph node biopsy using indocyanine green (ICG) for the surgical staging of early-stage endometrial cancer in comparison to technetium-99 m use.

METHODS

We conducted an observational retrospective study with patients diagnosed of endometrial cancer and FIGO stages I-II. All participants were injected technetium-99m the day prior to the surgery and underwent lymphoscintigraphy along with single-photon emission computed tomography. In addition, all patients were administered intraoperatively ICG injection to detect sentinel lymph node biopsy. The surgical staging was then completed according to the European Society for Medical Oncology preoperative risk category. Data obtained from the analysis of technetium-99m detection was compared to ICG detection.

RESULTS

A total of 53 women with endometrial cancer were included in the study, 49 (92.5%) of them showed drainage preoperatively in the single-photon emission computed tomography and/or lymphoscintigraphy. The intraoperative bilateral detection rate for technetium-99 m was 26 (49.1%) patients compared to 40 (75.5%) patients with ICG (p = 0.013). We observed a 42.5% increase in the mean number of lymph nodes retrieved by ICG compared to technetium-99m (2.85 vs 2,0 nodes; p = 0.002). We intraoperatively identified 164 lymph nodes, 104 (63.4%) located in both obturator areas and external iliac vessels.

CONCLUSION

The use of ICG for the performance of sentinel node biopsy in patients with endometrial cancer seems safe and could be superior to technetium-99 m, since it offers a higher bilateral detection rate and nodal retrieval, resulting in the possibility to perform safely less full staging lymphadenectomies.

Sentinel Lymph Node in Aged Endometrial Cancer Patients "The SAGE Study": A Multicenter Experience

OBJECTIVE

The incidence of endometrial cancer is increasing in elderly people. Considering that aging progressively affects lymphatic draining function, we aimed to define its impact on IGC uptake during SLN mapping.

METHODS

A multicenter retrospective cohort of endometrial cancer patients with apparently early-stage endometrial cancer undergoing complete surgical staging with SLN dissection was identified in four referral cancer centers from May 2015 to March 2021. Patients were classified in Group 1 (<65 years old) and Group 2 (≥65 years old). The primary endpoint was the assessment of the overall, bilateral, and unsuccessful SLN mapping in the two groups. Secondary outcomes were the evaluation of SLN anatomical distribution and the identification of predictors for mapping failure applying a logistic regression.

RESULTS

A total of 844 patients were enrolled in the study (499 in Group 1 and 395 in Group 2). The overall detection rate, the successful bilateral mapping, and the mapping failure rate of the SLN were 93.8% vs. 87.6% (p = 0.002), 77.1% vs. 66.8% (p = 0.001), and 22.9% vs. 33.2% (p = 0.001), respectively, in Group 1 vs. Group 2. The advanced age affects the anatomical distribution of the SLN leading to a stepwise reduction of "unexpected" mapping sites (left hemipelvis: p < 0.001; right hemipelvis: p = 0.058). At multivariate analysis age ≥ 65 (OR: 1.495, 95% CI: 1.095-2.042, p = 0.011), BMI (OR: 1.023, 95% CI: 1.000-1.046, p = 0.047), non-endometrioid histotype (OR: 1.619, 95% CI: 1.067-2.458, p = 0.024), and LVSI (OR: 1.407, 95% CI: 1.010-1.961, p = 0.044) represent independent predictors of unsuccessful mapping. Applying binomial logistic regression analysis, there was a 1.280-fold increase in the risk of failed mapping for every 10-year-old increase in age (OR: 1.280, 95% CI: 1.108-1.479, p = 0.001). A higher rate of surgical under-staging (0.9% vs. 3.3%, p = 0.012) and adjuvant undertreatment (p = 0.018) was reported in Group 2.

CONCLUSIONS

Old age represents a risk factor for SLN mapping failure both intrinsically and in relation to the greater incidence of other independent risk factors such as LVSI, non-endometrioid histotype, and BMI. Surgeons should target the usual uptake along UPP during the SLN dissection in this subgroup of patients to minimize mapping failure and the consequent risk of surgical under-staging and adjuvant undertreatment.

Sentinel node mapping in endometrial cancer: Tips and tricks to improve bilateral detection rate. The sentitricks study, a monocentric experience

OBJECTIVE

The objective of the study is to show some small tricks for bilateral sentinel lymph node (SLN) uptake in endometrial cancer.

MATERIALS AND METHODS

Each step of the sentinel lymph node technique was analyzed. The cervix was exposed through the use of vaginal valves and by Martin pliers stapling of the anterior cervical lip. Fifty mg Indocyanine Green (ICG) powder was diluted with 10 ml of physiological solution. The spinal needle was marked at 15 mm with a steri-strip. After 20 min from the administration, in case of no LNS identification, an additional 1 ml in the non-detected side was administered in the superficial cervical area. All cervical injections were made by a single (BR) surgeon experienced in oncological gynecology.

RESULTS

Fifty patients undergoing sentinel lymph node research for endometrial cancer. The uptake of at least one side of the sentinel node was 98% (49 cases). Forty-six (92%) patients had bilateral lymph node uptake and 3 patients (6%) had unilateral uptake. Only one patient with pelvic and metastatic aortic lymph nodes had no sentinel nodal uptake.

CONCLUSIONS

Little tricks can increase the bilateral uptake of the SLN up to 92%. The reinjection could be a key element for the success of the SLN technique. Experienced surgeons could certainly play a fundamental role in raising bilateral SLN detection. Further prospective randomized studies are needed to achieve the best SLN infiltration strategy.

Carbon nanoparticles combined with indocyanine green for sentinel lymph node detection in endometrial carcinoma

OBJECTIVE

To evaluate the feasibility and clinical value of the combination of carbon nanoparticles (CNPs) and indocyanine green (ICG) for identifying sentinel lymph nodes (SLNs) in endometrial cancer.

MATERIALS AND METHODS

About 153 patients with endometrial cancer were recruited from July 2015 to May 2019. All patients underwent SLN biopsy according to the SLN algorithm for surgical staging with ICG and/or CNPs. The detection rate, factors associated with the detection rate, sensitivity, and negative predictive value (NPV) of SLNs were analyzed.

RESULTS

The detection rates of SLNs with the combined method were the highest among the different methods. As calculated per hemipelvis, the sensitivity and NPV with ICG alone or with ICG plus CNPs were 100%. With CNP, tumor Grade 3 and laparoscopy were related to unsuccessful overall SLN mapping while tumor diameter greater than 2 cm and laparoscopy were statistically associated with failed bilateral mapping. With ICG, a higher body mass index was significantly associated with unsuccessful bilateral detection of SLN.

CONCLUSION

SLN assessment in endometrial cancer is feasible and safe with high sensitivity and high NPV when ICG and CNPs are combined and in low-risk patients. It is a superior option to use CNPs in laparotomy for patients with endometrial cancer.

Cervical re-injection of indocyanine green to improve sentinel lymph node detection in endometrial cancer

OBJECTIVES

To evaluate the role of cervical re-injection of indocyanine green (ICG) to increase the detection rate of sentinel lymph node (SLN) in patients with endometrial cancer (EC) who underwent robotic-assisted surgical staging.

METHODS

We retrospectively identified consecutive EC patients undergoing robotic-assisted staging with SLN biopsy at our Institution between June 2016 and April 2020. Patients were excluded if they had open abdominal surgical approach, neoadjuvant chemotherapy, and advanced stage [International Federation of Gynecology and Obstetrics (FIGO) stage III-IV] at diagnosis. According to our SLN protocol, in case of either unilateral or no SLN detection, we performed an ipsilateral or bilateral cervical re-injection of ICG.

RESULTS

In total, 251 patients meeting inclusion criteria were included in the analysis. At first injection, bilateral detection was achieved in 184 (73.3%), unilateral detection in 57 (22.7%), and no detection in 10 (4.0%) patients. Cervical re-injection was performed in 51 of 67 patients with failed bilateral mapping. After cervical re-injection, bilateral detection rate increased to 94.5% (222/235), while unilateral and no detection were 5.1% (12/235) and 0.4% (1/235), respectively.

CONCLUSIONS

Our results suggest that cervical re-injection of ICG, in case of failed bilateral mapping of SLN, brings about a significant improvement in SLN detection rates, therefore reducing the number of side-specific required lymphadenectomies.

Sentinel lymph node detection in endometrial cancer with indocyanine green: laparoscopic versus robotic approach

BACKGROUND

The aims of the present study were to assess bilateral sentinel lymph node (SLN) mapping with laparoscopic versus robotic approach, to assess variables affecting bilateral detection rates and to assess survival difference in patients with no/unilateral, compared to bilateral SLN detection.

METHODS

This is a retrospective, single-centre, observational cohort study, including patients with endometrial cancer FIGO stage IA-IVB, treated with minimally invasive primary surgery and undergoing indocyanine green (ICG) injection to detect SLN, between January 2015 and December 2019.

RESULTS

Of the 549 included patients, 286 (52.1%) and 263 (47.9%) underwent the laparoscopic and robotic approach respectively. 387 (70.5%) patients had bilateral SLN mapping, 102 (18.6%) and 60 (10.9%) had unilateral and no mapping, respectively. Patients who underwent the robotic approach were older (median 61 versus 64 years, p=0.046) and had a higher BMI (median 26.0 versus 34.8 kg/m2, p<0.001). No difference in any SLN mapping or in SLN bilateral detection was evident between the laparoscopic or robotic approach (p=0.892 and p=0.507 respectively). Patients with bilateral SLN detection in the entire cohort were younger (p<0.001) and had a better 3-year disease-free survival (DFS) compared to patients with no/unilateral SLN mapping (77.0% versus 66.3%, respectively, p=0.036). No 3-year overall survival (OS) difference was reported (p=0.491).

CONCLUSION

SLN mapping and bilateral SLN detection with ICG in endometrial cancer was not different in the laparoscopic and robotic approach, even though patients undergoing the robotic approach were older and more obese. Bilateral SLN detection was associated with improved 3-year DFS, but not with 3-year OS, compared to no and unilateral SLN detection.

Reduced lymphedema after sentinel lymph node biopsy versus lymphadenectomy for endometrial cancer

Objective

Endometrial cancer surgical staging includes lymph node assessment which can lead to lower extremity lymphedema. The aim of this study was to estimate prevalence after sentinel lymph node biopsy versus lymphadenectomy.

Methods

Consecutive patients who underwent minimally invasive surgery at the Mayo Clinic, Rochester, Minnesota, USA, between January 2009 and June 2016 for newly diagnosed endometrial cancer were mailed our validated 13 item lower extremity lymphedema screening questionnaire. We also ascertained via questionnaire whether the patient was ever diagnosed with lower extremity lymphedema.

Results

Among 378 patients included in the analysis, 127 (33.5%) had sentinel lymph node biopsy with or without side specific lymphadenectomy (sentinel lymph node cohort) and 251 (66.4%) underwent bilateral lymphadenectomy prior to sentinel lymph node biopsy implementation at our institution or as 'backup' after sentinel lymph node mapping (lymphadenectomy cohort). The prevalence of lower extremity lymphedema was 41.5% (157/378), with 69 patients (18.3%) self-reporting a lower extremity lymphedema diagnosis after their endometrial cancer surgery at a median of 54.3 months (interquartile range 31.2–70.1 months), and an additional 88 patients (23.3%) identified by the screening questionnaire. The prevalence of lower extremity lymphedema was significantly higher in the lymphadenectomy cohort compared with the sentinel lymph node group (49.4% (124/251) vs 26.0% (33/127); p<0.001). When the cohorts were restricted to patients surgically managed after the introduction of sentinel lymph node, the prevalence of lower extremity lymphedema was still significantly higher in the lymphadenectomy cohort compared with the sentinel lymph node cohort (39.0% (41/105) vs 26.0% (33/127); p=0.03). In a multivariable analysis adjusted for body mass index, receipt of adjuvant external beam radiation, diabetes, congestive heart failure, and International Federation of Gynecology and Obstetrics grade, the adjusted odds ratio for the association between type of nodal sampling (lymphadenectomy cohort vs sentinel lymph node cohort) and lower extremity lymphedema was 2.75 (95% confidence interval 1.69 to 4.47, p<0.001).

Conclusions

Sentinel lymph node biopsy was associated with a decreased risk of post-treatment lymphedema compared with lymphadenectomy in patients who underwent surgical staging for endometrial carcinoma.

Laparoscopic sentinel node mapping with intracervical indocyanine green injection for endometrial cancer: the SENTIFAIL study – a multicentric analysis of predictors of failed mapping

Objectives

Laparoscopy is commonly used for endometrial cancer treatment, and sentinel lymph node (SLN) mapping has become the standard procedure for nodal assessment. Despite the standardization of the technique, there is no definitive data regarding its failure rate. The objective of this study is to identify factors associated with unsuccessful SLN mapping in endometrial cancer patients undergoing laparoscopic SLN mapping after intracervical indocyanine green (ICG) injection.

Methods

We retrospectively evaluated a consecutive series of endometrial cancer patients who underwent laparoscopic SLN mapping with intracervical ICG injection, in four oncological referral centers from January 2016 to July 2019. Inclusion criteria were biopsy-proven endometrial cancer, total laparoscopic approach, and intracervical ICG injection. Exclusion criteria were evidence of lymph node involvement or extrauterine disease at pre-operative imaging, synchronous invasive cancer, the use of tracers different from ICG, and the use of neoadjuvant treatment. Bilateral and failed bilateral SLN mapping groups were compared for clinical and pathological features. In patients with an unsuccessful procedure, side-specific lymphadenectomy was performed. Logistic regression was used to identify predictors of failure.

Results

A total of 376 patients were included in the study. The overall bilateral and unilateral SLN detection rates were 96.3%, 76.3%, and 20.0% respectively. The failed bilateral mapping detection rate was 23.7%. The median number of sentinel nodes removed was 2.2 (range, 0–5). After multivariate analysis, lymph vascular space involvement [OR 2.4 (1.04–1.12), P=0.003], non-endometrioid histology [OR 3.0 (1.43–6.29), P=0.004], and intraoperative finding of enlarged lymph node [OR 2.3 (1.01–5.31), P=0.045] were identified as independent predictors of failure of SLN mapping.

Conclusion

Lymph vascular space involvement, non-endometrioid histology, and intra-operative finding of enlarged lymph nodes were identified as independent risk factors for unsuccessful mapping in patients undergoing laparoscopic SLN mapping.

Technetium-99m-indocyanine green versus technetium-99m-methylene blue for sentinel lymph node biopsy in early-stage endometrial cancer

INTRODUCTION

The low accuracy of pre-operative imaging techniques for prediction of nodal status strengthens the relevance of sentinel lymph node (SLN) biopsy in endometrial cancer, although the optimal method for its detection is still under investigation. The increasing use of indocyanine green (ICG) has aroused concern about its enhanced visualization of lymphatic channels, which could lead to a specimen that is thought to be nodal tissue not subsequently yielding a lymph node on pathologic analysis ('empty node packet'). Our main objective was to compare the overall and bilateral detection rates for SLN biopsy using two combined techniques: technetium-99m-ICG (Tc-99m-ICG) versus technetium-99m-methylene blue (Tc-99m-MB). Our secondary aim was to compare the 'empty node packet' rates between the two cohorts.

METHODS

A prospective, non-randomized, single-center trial including patients diagnosed with endometrial cancer (any grade or histology) in pre-operative early stage, and operated on between February 2017 and July 2019. All tracers were injected intracervically. Pelvic and aortic lymphadenectomy were performed on patients at intermediate or high risk of recurrence pre-operatively. All SLNs were sent for intra-operative frozen section and afterwards processed following an ultrastaging protocol.

RESULTS

Eighty-four patients were included, 58% (n=49) in the Tc-99m-MB group and 42% (n=35) in the Tc-99m-ICG group. Overall detection rate was 93% and was not statistically different between the two groups. A better bilateral detection rate was observed among Tc-99m-ICG patients (69% vs 41%, p=0.012). The 'empty node packet' rate was 4% in the Tc-99m-ICG cohort and 0% in the Tc-99m-MB cohort (p=0.032).

DISCUSSION

Tc-99m-ICG is a feasible, safe technique for SLN biopsy in early-stage endometrial cancer, and appears to be superior in terms of bilateral detection to Tc-99m-MB. The addition of Tc-99m to ICG could decrease the rate of 'empty node packets' and better define the anatomic location of SLNs in patients with endometrial cancer.