Value of indocyanine green pelvic lymph node mapping in the surgical approach of cervical cancer

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.

Impact of Indocyanine Green Dose on Sentinel Lymph Node Mapping in Cervical Cancer: A Systematic Review

Over the past decade, SLN mapping has become increasingly important in cervical cancer surgery. ICG is the most commonly used tracer due to its high bilateral detection rates, ease of use, and safety. However, there is no consensus on the optimal ICG dose, leading to variability in outcomes. This systematic review aims to evaluate the impact of different ICG doses on SLN detection in early-stage cervical cancer, identifying the most effective and safe dose for clinical practice. A comprehensive search was conducted in MEDLINE/PubMed up to May 2024. Studies included assessed SLN mapping using ICG in stage IA2-IIA/IIB cervical cancer. Exclusions were applied to studies not reporting ICG dose or using multiple tracers without dose-specific results. Twelve studies were included, with ICG concentrations ranging from 0.25 mg/mL to 25 mg/mL and injection volumes from 1 to 10 mL. Overall SLN detection rates ranged from 88% to 100%, while bilateral detection rates varied between 74.1% and 98.5%. The most consistent results were obtained with an ICG concentration of 1.25 mg/mL and a 4 mL injection volume. In conclusion, an ICG concentration of 1.25 mg/mL with a 4 mL injection volume is recommended for effective SLN mapping in cervical cancer, achieving high detection rates with minimal variability. Standardizing this dose in clinical practice is suggested to improve reproducibility and outcomes.

Indocyanine green-guided sentinel lymph node mapping during laparoscopic surgery with vaginal cuff closure but no uterine manipulator for cervical cancer

BACKGROUND

Lymph node metastasis is a critical prognostic factor in cervical cancer. Considering the potential complications of lymphadenectomy and desirability of avoiding systemic lymphadenectomy, accurate intraoperative prediction of the existence of lymph node metastasis is important in patients undergoing surgery for cervical cancer. We evaluated the feasibility and value of indocyanine green (ICG) use for sentinel lymph node (SLN) mapping during laparoscopic surgery performed for cervical cancer.

METHODS

This single-center cohort study included 77 patients undergoing a new laparoscopic radical surgery method with pelvic lymphadenectomy for early-stage cervical cancer. The surgery, performed without using a uterine manipulator, included creation of a vaginal cuff. Bilateral ICG-guided SLN mapping and rapid histopathological examination were performed, and results were analyzed in relation to final histopathologic diagnoses.

RESULTS

The SLN pelvic side-specific detection rate was 93.5%, sensitivity (SLN-positive cases/SLN-detected pelvic lymph node-positive cases) was 100%, intraoperative negative predictive value (NPV) was 97.8%, and final pathological NPV was 100%. The detection rate was significantly lower for tumors ≥ 2 cm in diameter than for tumors < 2 cm in diameter. Micrometastases were missed by intraoperative examination in 3 cases.

CONCLUSION

The high NPV suggests the feasibility and usefulness of ICG-based SLN mapping plus rapid intraoperative examination for identification of metastatic SLNs. Use of ICG-based mapping for intraoperative identification of SLNs in patients undergoing this new laparoscopic surgery method for early-stage cervical cancer was particularly effective for tumors < 2 cm in diameter. However, incorporating a search for micrometastases into rapid intraoperative histopathologic examination may be necessary.

Sentinel node navigation surgery in cervical cancer: a systematic review and metaanalysis

Sentinel node navigation surgery (SNNS) is used in clinical practice for the treatment of cervical cancer. This study aimed to elucidate the appropriate sentinel lymph node (SLN) mapping method and assess the safety and benefits of SNNS. We searched the PubMed, Ichushi, and Cochrane Library databases for randomized controlled trials (RCT) and studies on SLN in cervical cancer from January 2012 to December 2020. Two authors independently assessed study quality and extracted data. We quantitatively analyzed the detection rate, sensitivity/specificity, and complications and reviewed information, including the survival data of SLN biopsy (SLNB) without pelvic lymphadenectomy (PLND). The detection rate of SLN mapping in the unilateral pelvis was median 95.7% and 100% and in the bilateral pelvis was median 80.4% and 90% for technetium-99 m (Tc) with/without blue dye (Tc w/wo BD) and indocyanine green (ICG) alone, respectively. The sensitivity and specificity of each tracer were high; the area under the curve of each tracer was 0.988 (Tc w/wo BD), 0.931 (BD w/wo Tc), 0.966 (ICG), and 0.977 (carbon nanoparticle). Morbidities including lymphedema, neurological symptoms and blood loss were associated with PLND. One RCT and five studies all showed SNNS without systematic PLND does not impair recurrence or survival in early-stage cervical cancer with a tumor size ≤ 2-4 cm. Both Tc w/wo BD and ICG are appropriate SLN tracers. SNNS can reduce the morbidities associated with PLND without affecting disease progression in early-stage cervical cancer.