Methylene blue-assisted lymph node dissection in combination with ex vivo sentinel lymph node mapping in gastric cancer

Assessment of the efficacy and safety of carbon nanoparticles-guided lymph node dissection in gastric cancer surgery: a systematic review and meta-analysis

BACKGROUND

To investigate the efficacy and safety of lymph nodes (LNs) dissection guided by carbon nanoparticles (CNs) in gastric cancer (GC) surgery.

MATERIALS AND METHODS

We searched electronic databases such as PubMed, Web of Science, Embase, Cochrane Library, and Scopus for relevant articles up to September 2022 and collected all studies comparing the CNs group with blank controls group on the efficacy and safety of LN dissection in gastrectomy. A pooled analysis of the collected data was performed, including the number of retrieved LNs, the staining rate of LNs, the number of metastatic LNs dissection, various intraoperative outcomes, and postoperative complications.

RESULTS

A total of 9 studies including 1770 participants (502 in the CNs group and 1268 in the control group) were included. As compared to the blank control group, the CNs group detected 10.46 more LNs in each patient (WMD = 10.46, 95% CI: 6.63 ~ 14.28, p < 0.00001, I² = 91%), and also significantly more metastatic LNs (WMD = 2.63, 95% CI: 1.43 ~ 3.83, p < 0.0001, I² = 41%). However, there was no significant difference in the rate of metastatic LNs between the CNs and control groups (OR = 1.37, 95% CI: 0.94 ~ 2.00, P = 0.1, I² = 89%). In addition, there was no increase in operative time, intraoperative blood loss, and postoperative complications associated with CNs-guided gastrectomy.

CONCLUSION

CNs-guided gastrectomy is safe and effective, and can increase the efficiency of LN dissection without increasing the risk of surgery.

Examined lymph node count for gastric cancer patients after curative surgery

Lymph node (LN) metastasis is the most common form of metastasis in gastric cancer (GC). The status and stage of LN metastasis are important indicators that reflect the progress of GC. The number of LN metastases is still the most effective index to evaluate the prognosis of patients in all stages of LN metastasis. Examined LN (ELN) count refers to the number of LNs harvested from specimens by curative gastrectomy for pathological examination. This review summarizes the factors that influence ELN count, including individual and tumor factors, intraoperative dissection factors, postoperative sorting factors, and pathological examination factors. Different ELN counts will lead to prognosis-related stage migration. Fine LN sorting and regional LN sorting are the two most important LN sorting technologies. The most direct and effective way to harvest a large number of LNs is for surgeons to perform in vitro fine LN sorting.

Optical molecular imaging can differentiate metastatic from benign lymph nodes in head and neck cancer

Identification of lymph node (LN) metastasis is essential for staging of solid tumors, and as a result, surgeons focus on harvesting significant numbers of LNs during ablative procedures for pathological evaluation. Isolating those LNs most likely to harbor metastatic disease can allow for a more rigorous evaluation of fewer LNs. Here we evaluate the impact of a systemically injected, near-infrared fluorescently-labeled, tumor-targeting contrast agent, panitumumab-IRDye800CW, to facilitate the identification of metastatic LNs in the ex vivo setting for head and neck cancer patients. Molecular imaging demonstrates a significantly higher mean fluorescence signal in metastatic LNs compared to benign LNs in head and neck cancer patients undergoing an elective neck dissection. Molecular imaging to preselect at-risk LNs may thus allow a more rigorous examination of LNs and subsequently lead to improved prognostication than regular neck dissection.

Techniques to increase lymph node harvest from gastrointestinal cancer specimens: a systematic review and meta-analysis

AIMS

This review aims to compare different histopathological techniques for lymph node harvest from ex-vivo gastrointestinal cancer specimens and to examine their influence on: (i) lymph node yield; (ii) positive lymph node detection; and (iii) cancer staging.

METHOD AND RESULTS

Systematic review of the English language literature to 10 October 2011, comparing manual nodal dissection to other techniques for lymph node harvest. The methodological quality of included studies was assessed. Twenty-seven studies, examining fat clearing, methylene blue staining, fat stretching and use of a dedicated pathology assistant, were assessed. The methodological quality of the majority of included studies was poor. Meta-analysis showed that fat clearing and methylene blue staining increased mean lymph node yield by 13 and 15 nodes, respectively, when compared to manual dissection. Of the 15 studies reporting positive lymph node count, two demonstrated a significant improvement for techniques other than manual dissection. Compared to manual dissection, other techniques were not shown to influence cancer staging.

CONCLUSION

This review has shown that fat clearing and methylene blue staining increases the mean lymph node yield from gastrointestinal cancer specimens. There is insufficient evidence to suggest that these techniques increase positive lymph node count or lead to upstaging.

[Lymph node staging in gastrointestinal cancer. Combination of methylene blue-assisted lymph node dissection and ex vivo sentinel lymph node mapping]

The histopathological lymph node staging is of crucial importance for the prognosis estimation and therapy stratification in gastrointestinal cancer. However, the recommended numbers of lymph nodes that should be evaluated are often not reached in routine practice. Methylene blue assisted lymph node dissection was introduced as a new, simple and efficient technique to improve lymph node harvest in gastrointestinal cancer. This method is inexpensive, causes no delay and needs no toxic substances. All studies performed revealed a highly significantly improved lymph node harvest in comparison to the conventional technique. Moreover, this technique can be combined with a new ex vivo sentinel lymph node mapping that for the first time is based on histological sentinel lymph node detection. The success rate of this method is similar to conventional techniques and it enables an efficient application of extended investigation methods, such as immunohistochemistry or the polymerase chain reaction.

Injection of methylene blue solution into the inferior mesenteric artery of resected rectal specimens for rectal cancer as a method for increasing the lymph node harvest

BACKGROUND

The aim of the present study was to determine whether the injection of methylene blue solution into the inferior mesenteric artery could improve the lymph node harvest in rectal specimens of rectal cancer patients treated with rectal resection with total mesorectal excision.

METHODS

The study group consisted of 20 randomly selected fresh rectal specimens from patients with stages I-III rectal cancer treated at the Surgery Clinic at the Institute of Oncology of Vilnius University during the period from February 2008 to December 2010, and 20 specimens were selected under the same conditions to serve as the control group. The patients underwent conventional rectal resection with total mesorectal excision and coloanal anastomosis for low rectal cancer performed by the same surgeon, did not receive preoperative radiotherapy and had no distant metastases. After the removal of the specimen, 30 ml of 0.5% methylene blue solution was injected into the inferior mesenteric artery of the specimens in the study group (methylene blue group). The specimens from both the methylene blue and control groups were examined using the standards established by the Lithuanian National Centre of Pathology. The pathologist was not required to make any special macroscopic preparations. A retrospective analysis of clinical and histopathological records was performed.

RESULTS

Comparison of the mean lymph node harvest showed a significant difference between methylene blue and control groups with average lymph node numbers per specimen of 18 ± 5 and 14 ± 6, respectively (p = 0.025). The specimens from 12 of the 20 patients in the methylene blue group and the specimens from 7 of the 20 patients from the control group had positive nodes.

CONCLUSIONS

Injecting methylene blue solution into the inferior mesenteric artery is an efficient and simple method for improving the lymph node harvest in the histopathological examination of rectal specimens of rectal cancer patients treated with rectal resection with total mesorectal excision.

Sentinel lymph node mapping by a near-infrared fluorescent heptamethine dye

We describe a near-infrared fluorescent heptamethine dye (IR-780 iodide) with unique properties for sentinel lymph node (SLN) mapping in both small and large animals. This dye has a significant photobrightening effect in serum and a long retention time in the lymphatic system which allows to acquire much higher signal-to-noise ratios. Injection of only 10 nmol of this dye permits SLNs to be imaged easily in pigs using excitation fluence rates of only 2 microW/cm(2). In addition, this dye has a unique stability property after formalin fixation in tissues which raises the possibility of developing new and sensitive means of detecting lymph nodes in harvested surgical specimens. This dye can be completely cleared from the circulation in a couple of days and does not cause acute systemic toxicity.