Sentinel node procedures in gynecologic cancers: an overview

Nonselective Lymph Node Dissection and Sentinel Lymph Node Mapping and Biopsy

Clinical staging is important for determining the extent of disease in animals with malignant cancers. The status of the lymph node will help determine whether adjuvant treatment is indicated. Historically, the regional anatomic lymph node has been sampled to determine the presence or absence of metastatic disease, but there is increasing evidence that the regional anatomic lymph node is often different to the sentinel lymph node. As a result, several sentinel lymph node mapping techniques have been described for more accurate clinical staging of oncologic patients.

A GCIG international survey: clinical practice patterns of sentinel lymph node biopsies in cervical cancer

PURPOSE

To evaluate the practice patterns among centers and physicians worldwide regarding sentinel lymph node biopsies (SLNB) in cervical cancer (CC) patients.

METHOD

A validated 35-item questionnaire regarding SLNB in CC supported by the Gynecologic Cancer Intergroup (GCIG), and sponsored by the North-Eastern German Society of Gynaecologic-Oncology (NOGGO) was sent to all major gynecological cancer societies across the globe for further distribution from October 2015 and continued for a period of 7 months.

RESULTS

One hundred and sixty-one institutions from around the world participated. One hundred and six (66%) of the participants were from university centers and 111 (69%) were gynecologic oncologists. One hundred and fifty-two (97%) performed lymphadenectomy (LNE) and 147 (94%) did so systematically; 97 (60%) used SLNB, due to lower morbidity (73%), reliability (55%) and time-saving (27%). In cases of positive SLNB (pN+), 39% of respondents stopped the operation and sent the patient for chemoradiation (CRT), 45% completed pelvic and paraaortic LNE, whereas 26% went on to perform a radical hysterectomy (RH) and systematic pelvic and paraaortic LNE. In case of negative SLNB (pN0), 39% of institutions still performed a systematic pelvic and paraaortic LNE.

CONCLUSION

In this survey worldwide, SLNB adoption is an encouraging 60%, yet ample differences exist regarding strategy, and to a lower extent the techniques used. Lack of experience is the most common reason SLNB is not performed. Efforts to increase surgical education on SLNB technique and multicenter prospective trials providing evidence-based guidelines are warranted.

How to Handle Lymphadenectomy Specimens to Identify Metastasis More Accurately in Gynecologic Pathology

AIM

To identify the value of processing multiple sections to detect metastasis in lymph nodes (LNs) dissected during gynecologic cancer surgery, and to evaluate the sizes of metastatic LNs in each region to compare with the largest one.

MATERIALS AND METHODS

This retrospective study included 362 patients who had gynecologic cancer with at least one metastatic LN. Slides of 627 metastatic LN specimens were categorized according to the processing technique into single and more than one section (MOS) groups. In the MOS group, the LNs were cut into 2 or 3 parallel slices because their greatest dimensions exceeded 0.5 cm. Sizes of LN metastatic foci (MF) were measured and defined as follows: MF ⩽2 mm as micrometastasis and MF >2 mm as macrometastasis. The largest LN diameters among the metastatic LNs and the largest LNs in those regions were measured. Groups were compared using the Kruskal-Wallis test.

RESULTS

Sixty-five (10.3%) of the metastatic LNs included in this study had micrometastases and 40 (6.3%) of them had MF ⩽1 mm. The rate of micrometastasis was higher in the MOS group than in the single-section group (11.8% vs 8.5%, respectively). Twenty-eight percent (n = 175) of metastatic LNs were not the largest, and 55.5% of those were less than 1 cm in diameter.

CONCLUSION

Methods of LN processing and macroscopic evaluation are not standardized, and processing single sections from LNs may overlook micrometastases. The detection rate of micrometastases can be improved by processing multiple sections from LNs.

Minimally invasive electro-magnetic navigational bronchoscopy-integrated near-infrared-guided sentinel lymph node mapping in the porcine lung

Background

The use of near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) for sentinel lymph node (SN) mapping has been investigated in lung cancer; however, this has not been fully adapted for minimally invasive surgery (MIS). The aim of our study was to develop a minimally invasive SN mapping integrating pre-operative electro-magnetic navigational bronchoscopy (ENB)-guided transbronchial ICG injection and intraoperative NIR thoracoscopic imaging.

Methods

A NIR thoracoscope was used to visualize ICG fluorescence. ICG solutions in a 96-well plate and ex vivo porcine lungs were examined to optimize ICG concentrations and injection volumes. Transbronchial ICG injection (n=4) was assessed in comparison to a traditional transpleural approach (n=3), where after thoracotomy an ICG solution (100μL at 100μg/mL) was injected into the porcine right upper lobe for SN identification. For further translation into clinical use, transbronchial ICG injection prior to thoracotomy followed by NIR thoracoscopic imaging was validated (n=3). ENB was used for accurate targeting in two pigs with a pseudo-tumor.

Results

The ICG fluorescence at 10 μg/mL was the brightest among various concentrations, unchanged by the distance between the thoracoscope and ICG solutions. Injected ICG of no more than 500μL showed a localized fluorescence area. All 7 pigs showed a bright paratracheal lymph node within 15 minutes post-injection, with persistent fluorescence for 60 minutes. The antecedent transbronchial ICG injection succeeded in SN identification in all 3 cases at the first thoracoscopic inspection within 20 minutes post-injection. The ENB system allowed accurate ICG injection surrounding the pseudo-tumors.

Conclusions

ENB-guided ICG injection followed by NIR thoracoscopy was technically feasible for SN mapping in the porcine lung. This promising platform may be translated into human clinical trials and is suited for MIS.

Sentinel lymph node biopsy in uterine cervical cancer patients: ready for clinical use? A review of the literature

Sentinel lymph node biopsy has been widely studied in a number of cancer types. As far as cervical cancer is concerned, this technique has already been used, revealing both positive results and several issues to be solved. The debate on the role of sentinel lymph node biopsy in cervical cancer is still open although most of the studies have already revealed its superiority over complete lymphadenectomy and the best handling possible of the emerging practical problems. Further research should be made in order to standardize this method and include it in the clinical routine.

Definition of compartment based radical surgery in uterine cancer-part I: therapeutic pelvic and periaortic lymphadenectomy by Michael höckel translated to robotic surgery

Objective. To define compartment based therapeutic pelvic and periaortic lymphadenectomy in cervical and endometrial cancer. Compartment based oncologic surgery appears to be favorable for patients in terms of radicality as well as complication rates, and the same appears to be true for robotic surgery. We describe a method of robotically assisted compartment based lymphadenectomy step by step in uterine cancer and demonstrate feasibility data from 35 patients. Methods. Patients with the diagnosis of endometrial (n = 16) or cervical (n = 19) cancer were included. Patients were treated by rTMMR (robotic total mesometrial resection) or rPMMR (robotic peritoneal mesometrial resection) and pelvic or pelvic/periaortic rtLNE (robotic therapeutic lymphadenectomy) with cervical cancer FIGO IB-IIA or endometrial cancer FIGO I-III. Results. No transition to open surgery was necessary. Complication rates were 13% for endometrial cancer and 21% for cervical cancer. Within follow-up time median (22/20) month we noted 1 recurrence of cervical cancer and 2 endometrial cancer recurrences. Conclusions. We conclude that compartment based rtLNE is a feasible and safe technique for the treatment of uterine cancers and is favorable in aspects of radicality and complication rates. It should be analyzed in multicenter studies with extended followup on the basis of the described technique.

Near-infrared fluorescence sentinel lymph node biopsy in vulvar cancer: a randomised comparison of lymphatic tracers

This study aims to confirm the feasibility of near-infrared (NIR) fluorescence imaging for sentinel lymph node (SLN) biopsy in vulvar cancer and to compare the tracer indocyanine green (ICG) bound to human serum albumin (HSA) versus ICG alone. Women received 99mTc-nanocolloid and patent blue for SLN detection. Subsequently, women randomly received ICG:HSA or ICG alone. In 24 women, 35 SLNs were intraoperatively detected. All SLNs detected were radioactive and NIR fluorescent and 27 (77%) were blue. No significant difference was found between ICG:HSA and ICG alone. This trial confirms the feasibility of NIR fluorescence imaging for SLN mapping in vulvar cancer.