Effect of activated carbon nanoparticles on lymph node harvest in patients with colorectal cancer

Safety and effectiveness of carbon nanoparticles suspension-guided lymph node dissection during thyroidectomy in patients with thyroid papillary cancer: a prospective, multicenter, randomized, blank-controlled trial

Objective

This study aimed to evaluate the effectiveness and safety of carbon nanoparticles-guided lymph node dissection during thyroidectomy in patients with papillary thyroid cancer(PTC).

Methods

Clinical trials consisted of two subgroups: unilateral lobectomy (UL; n=283) and total thyroidectomy (TT; n=286). From each subgroup, the patients were randomly assigned to two groups: the carbon nanoparticle group and control group. Primary endpoints included parathyroid hormone (PTH) levels, number of lymph nodes (LNs) detected, number of tiny lymph nodes detected, and recognition and retention of the parathyroid glands. Secondary endpoint was recognition and protection of the recurrent laryngeal nerve.

Results

A total of 569 patients with PTC were recruited. There were no statistically significant differences in demographics between the carbon nanoparticles and control groups (P > 0.05). In the UL subgroup, there were no significant differences in PTH levels between the two groups at preoperative, intraoperative, and postoperative day one, and postoperative month one (P>0.05). There was no significant difference in the serum Ca2+ levels between the two groups preoperatively and at postoperative month one (P>0.05). The number of lymph nodes dissected in the carbon nanoparticles group was significantly higher than that in the control group (P<0.0001). The detection rate of tiny lymph nodes in the carbon nanoparticles group was higher than that in the control group (P=0.0268). In the TT subgroup, there was no significant difference in PTH levels between the two groups at preoperative, intraoperative, and postoperative day one (P>0.05). However, the mean PTH level in the carbon nanoparticles group was significantly higher than that of the control group at postoperative month one (P=0.0368). There was no significant difference in the serum Ca2+ levels between the two groups preoperatively and at postoperative month one (P>0.05). There were no significant differences between the two groups in the number of dissected LNs (P>0.05) or the detection rate of tiny lymph nodes (P>0.05). No drug-related AE and complications due to the injection of carbon nanoparticles were recorded in this study. There were no significant differences between the two groups in terms of parathyroid preserved in situ and recurrent laryngeal nerve injury in the UL and TT subgroups.

Conclusions

Carbon nanoparticles demonstrated efficacy and safety in thyroidectomy. The application of carbon nanoparticles could significantly facilitate the identification and clearance of LNs and the optimum preservation of parathyroid function.

Clinical trial registration

https://www.chictr.org.cn/, identifier ChiCTR2300068502.

The Role of Carbon Nanoparticles as Lymph Node Tracers in Colorectal Cancer: A Systematic Review and Meta-Analysis

Colorectal malignancies are the third-most common malignancies worldwide, with a rising incidence. Surgery remains the treatment of choice and adequate lymph node dissection is required for accurate staging. The objective of this study is to assess the use of carbon nanoparticles in lymph node tracing and resection in cases of colorectal cancer. For that purpose, we conducted a systematic review and meta-analysis of studies included in Medline, Scopus, Embase, Cochrane Library, and Google Scholar databases. In the end, ten studies with a total number of 1418 patients were included in the final statistical analysis. The meta-analysis carried out showed that the use of carbon nanoparticles results in an increased number of lymph nodes harvested (WMD 6.15, 95% CI 4.14 to 8.16, p < 0.001) and a higher rate of cases with more than 12 lymph nodes harvested (OR 9.57, 95% CI 2.87 to 31.96, p = 0.0002). As a consequence, we suggest that carbon nanoparticles are used on a wider scale and that future research focuses on assessing the association between their use and overall patient survival. This study is limited by the fact that all included studies originate from China and by the fact that certain oncologic parameters and long-term outcomes have not been taken into account in the analysis.

Use of Carbon Nanoparticles to Improve the Efficiency of Harvesting Lymph Nodes in Rectal Cancer

BACKGROUND

The accurate determination of lymph node status in patients with rectal cancer requires harvesting a certain number of lymph nodes. This study investigated whether using carbon nanoparticles (CNs) could improve the efficiency of harvesting lymph nodes in rectal cancer patients.

MATERIALS AND METHODS

Data from patients with rectal cancer treated with radical resection were collected from Nanfang Hospital between January 2014 and June 2021. Patients in the CN group received a CN suspension 1 day before surgery, which was endoscopically injected around the tumor. A 1:1 case-matched study was performed using the propensity score. The efficiency of harvesting lymph nodes was investigated by comparing the number of total nodes, total time, and percentage of nodes <5 mm in size between the CN and non-CN groups.

RESULTS

A total of 768 patients were included, with 246 patients who underwent CN injection and 522 patients who did not. After matching, 246 pairs of patients were analyzed. After matching, the number of total nodes of each sample was significantly higher in the CN group than in the non-CN group ( P <0.001). The total time for node detection ( P <0.001) was significantly shorter in the CN group. The percentage of nodes <5 mm in size was increased significantly in the CN group ( P <0.001). Among patients with clinical staging I/II, the difference in positive LNs was significant (21.79% vs. 11.95%, P =0.029).

CONCLUSIONS

The application of CNs improved the efficiency of harvesting lymph nodes during rectal cancer surgery.

Lymphatic Mapping in Colon Cancer Depending on Injection Time and Tracing Agent: A Systematic Review and Meta-Analysis of Prospective Designed Studies

An optimized lymph node yield leads to better survival in colon cancer, but extended lymphadenectomy is not associated with survival benefits. Lymphatic mapping shows several colon cancers feature aberrant drainage pathways inducing local recurrence when not resected. Currently, different protocols exist for lymphatic mapping procedures. This meta-analysis assessed which protocol has the best capacity to detect tumor-draining and possibly metastatic lymph nodes. A systematic review was conducted according to PRISMA guidelines, including prospective trials with in vivo tracer application. The risk of bias was evaluated using the QUADAS-2 tool. Traced lymph nodes, total resected lymph nodes, and aberrant drainage detection rate were analyzed. Fifty-eight studies met the inclusion criteria, of which 42 searched for aberrant drainage. While a preoperative tracer injection significantly increased the traced lymph node rates compared to intraoperative tracing (30.1% (15.4, 47.3) vs. 14.1% (11.9, 16.5), p = 0.03), no effect was shown for the tracer used (p = 0.740) or the application sites comparing submucosal and subserosal injection (22.9% (14.1, 33.1) vs. 14.3% (12.1, 16.8), p = 0.07). Preoperative tracer injection resulted in a significantly higher rate of detected aberrant lymph nodes compared to intraoperative injection (26.3% [95% CI 11.5, 44.0] vs. 2.5% [95% CI 0.8, 4.7], p < 0.001). Analyzing 112 individual patient datasets from eight studies revealed a significant impact on aberrant drainage detection for injection timing, favoring preoperative over intraoperative injection (OR 0.050 [95% CI 0.010-0.176], p < 0.001) while indocyanine green presented itself as the superior tracer (OR 0.127 [95% CI 0.018-0.528], p = 0.012). Optimized lymphatic mapping techniques result in significantly higher detection of aberrant lymphatic drainage patterns and thus enable a personalized approach to reducing local recurrence.

Carbon-Based Nanomaterials as Drug Delivery Agents for Colorectal Cancer: Clinical Preface to Colorectal Cancer Citing Their Markers and Existing Theranostic Approaches

Colorectal cancer (CRC) is one of the universally established cancers with a higher incidence rate. Novel progression toward cancer prevention and cancer care among countries in transition should be considered seriously for controlling CRC. Hence, several cutting edge technologies are ongoing for high performance cancer therapeutics over the past few decades. Several drug-delivery systems of the nanoregime are relatively new in this arena compared to the previous treatment modes such as chemo- or radiotherapy to mitigate cancer. Based on this background, the epidemiology, pathophysiology, clinical presentation, treatment possibilities, and theragnostic markers for CRC were revealed. Since the use of carbon nanotubes (CNTs) for the management of CRC has been less studied, the present review analyzes the preclinical studies on the application of carbon nanotubes for drug delivery and CRC therapy owing to their inherent properties. It also investigates the toxicity of CNTs on normal cells for safety testing and the clinical use of carbon nanoparticles (CNPs) for tumor localization. To conclude, this review recommends the clinical application of carbon-based nanomaterials further for the management of CRC in diagnosis and as carriers or therapeutic adjuvants.

Nanoparticles in the diagnosis and treatment of cancer metastases: Current and future perspectives

Metastasis accounts for greater than 90% of cancer-related deaths. Despite recent advancements in conventional chemotherapy, immunotherapy, targeted therapy, and their rational combinations, metastatic cancers remain essentially untreatable. The distinct obstacles to treat metastases include their small size, high multiplicity, redundancy, therapeutic resistance, and dissemination to multiple organs. Recent advancements in nanotechnology provide the numerous applications in the diagnosis and prophylaxis of metastatic diseases, including the small particle size to penetrate cell membrane and blood vessels and their capacity to transport complex molecular 'cargo' particles to various metastatic regions such as bones, brain, liver, lungs, and lymph nodes. Indeed, nanoparticles (NPs) have demonstrated a significant ability to target specific cells within these organs. In this regard, the purpose of this review is to summarize the present state of nanotechnology in terms of its application in the diagnosis and treatment of metastatic cancer. We intensively reviewed applications of NPs in fluorescent imaging, PET scanning, MRI, and photoacoustic imaging to detect metastasis in various cancer models. The use of targeted NPs for cancer ablation in conjunction with chemotherapy, photothermal treatment, immuno therapy, and combination therapy is thoroughly discussed. The current review also highlights the research opportunities and challenges of leveraging engineering technologies with cancer cell biology and pharmacology to fabricate nanoscience-based tools for treating metastases.

Methylene blue can increase the number of lymph nodes harvested in colorectal cancer: a meta-analysis

AIM

The lymph node (LN) status plays an important role in colorectal cancer (CRC), which depends on adequate LN harvest. In some studies, methylene blue has been used to increase the number of LNs harvested in vitro. The purpose was to evaluate the effect of methylene blue staining on LN harvest during radical resection of CRC.

METHODS

The Cochrane Library, MEDLINE, Embase, PubMed, and Web of Science were searched from the dates of inception until 15 October 2022. Studies were included if they were randomized controlled trials or nonrandomized controlled trials for radical resection of rectal cancer according to the principle of total mesorectal excision that compared the use of methylene blue with blank control in LN harvest. The primary outcomes were the number of LNs harvested and the incidence of fewer than 12 LNs harvested.

RESULT

Of 328 articles found, a meta-analysis was conducted of 15 studies (2 randomized controlled trials and 13 non-randomized controlled trials) composed of 3104 patients. Meta-analysis showed that methylene blue could not only significantly increase the number of LNs harvested in CRC specimens (stained group 28.23 vs unstained group 16.15; weighted mean difference 12.08; 95% CI, 8.03-16.12; p < 0.001; I² = 95%), but also reduce the incidence of fewer than 12 LNs harvested (methylene blue-stained group 7.91% vs unstained group 30.90%; OR 0.12; 95% CI, 0.05-0.26; p < 0.001; I² = 78%).

CONCLUSION

Methylene blue can increase the number of LNs harvested in CRC, reduce the incidence of fewer than 12 LNs harvested, and ensure the accuracy of LN staging.

Lymph node stain after radical resection of rectal cancer mainly increased the harvest of mini lymph node: A randomized controlled trial

AIM

The lymph node status plays an important role in rectal cancer, which depends on adequate lymph node harvest. Lymph node stain techniques increase the lymph node harvest. The aim of this prospective study is to investigate which subgroups of lymph nodes harvested were increased mostly.

METHODS

From May 2020 to May 2022, 172 stage II-III rectal cancer patients were randomized to methylene blue (MB) stained group or unstained group to retrieve the lymph nodes. Methylene blue solution was injected into the inferior mesenteric artery, we dissected lymph nodes by palpation and sight. The lymph nodes were divided into 3 groups depending on the anatomy (main lymph nodes, superior rectal and perirectal lymph nodes (SPLNs), and pericolic lymph nodes located beyond 10 cm proximal to the tumor), and 3 groups depending on the short diameter of the nodes (big: ≥ 5 mm, small: 5-2 mm, mini: ≤ 2 mm).

RESULTS

The number of lymph nodes harvested with MB was significantly higher (22.0 (14.8, 32.0) vs 14.5 (11.0, 22.0); p < 0.001) without difference in positive patients or number of positive nodes. The positive rate of the big node was 3.5%, the small node was 1.9%, and the mini node was 0.2%. In the subgroup analysis, the median number of mini lymph nodes in the MB-stained group was significantly more than that of the unstained group (median (IQR): 9.0 (6.0, 14.0) vs 4.0 (2.0,6.0), p < 0.001); and the median number of SPLNs in the MB-stained group were significantly more than that of the unstained group (median (IQR): 15.0 (9.0, 19.0) vs 10.0 (6.0, 13.3), p < 0.001); these differences were existing in both patients with and without neoadjuvant treatments.

CONCLUSION

Intra-arterial injection of MB can significantly increase the number of lymph nodes harvested in rectal cancers, especially those mini lymph nodes. However, methylene blue staining did not significantly increase the number of positive lymph nodes and the proportion of patients with more than 12 lymph nodes, or affect lymph node staging accuracy after radical resection of rectal cancer.

The effect of carbon nanoparticles staining on lymph node tracking in colorectal cancer: A propensity score matching analysis

Purpose

The aim of this study was to evaluate the effect of carbon nanoparticles staining (CNS) on colorectal cancer (CRC) surgery, lymph node tracing and postoperative complications using propensity score matching (PSM).

Method

Patients who were diagnosed with CRC and underwent surgery were retrospectively collected from a single clinical center from Jan 2011 to Dec 2021. Baseline characteristics, surgical information and postoperative information were compared between the CNS group and the non-CNS group. PSM was used to eliminate bias.

Results

A total of 6,886 patients were enrolled for retrospective analysis. There were 2,078 (30.2%) patients in the CNS group and 4,808 (69.8%) patients in the non-CNS group. After using 1: 1 ratio PSM to eliminate bias, there were 2,045 patients left in each group. Meanwhile, all of their baseline characteristics were well matched and there was no statistical significance between the two groups (P > 0.05). In terms of surgical information and short-term outcomes, the CNS group had less intraoperative blood loss (P < 0.01), shorter operation time (P < 0.01), shorter postoperative hospital stay (P < 0.01), less metastatic lymph nodes (P = 0.013), more total retrieved lymph nodes (P < 0.01), more lymphatic fistula (P = 0.011) and less postoperative overall complications (P < 0.01) than the non-CNS group before PSM. After PSM, the CNS group had less intraoperative blood loss (P = 0.004), shorter postoperative hospital stay (P < 0.01) and more total retrieved lymph nodes (P < 0.01) than the non-CNS group. No statistical difference was found in other outcomes (P > 0.05).

Conclusion

Preoperative CNS could help the surgeons detect more lymph nodes, thus better determining the patient's N stage. Furthermore, it could reduce intraoperative blood loss and reduce the hospital stay.

Study on naked eye tracing of inguinal sentinel lymph nodes in penile cancer patients with carbon nanoparticle suspension injection

Objective

Exploratory study of the effect and clinical value of carbon nanoparticle suspension injection (CNSI) as a tracer for inguinal sentinel lymph nodes in penile cancer.

Method

We selected 29 patients with penile cancer in our department from January 2019 to October 2022. According to whether the CNSI tracer was injected during the pathological biopsy of the inguinal lymph nodes, the enrolled patients were assigned to the control group, the group in which CNSI was injected 12 h before the surgery (12HBS group) and the group in which CNSI was injected 0.5 h before the surgery (0.5HBS group). Evaluating the effectiveness of CNSI as a lymphatic tracer involves analyzing the following: its safety, the statistical analysis of the detection rate (DR) of different groups, the number of lymph nodes sent for each case (NOLNSFEC), the difference of positive rate of lymphatic metastasis (PROLM), and operation time (OT).

Results

The lymph nodes in the 12HBS group and 0.5HBS group had an obvious black staining appearance, and no adverse reactions or surgical complications were found. Most of the black-stained areas caused by CNSI injection were removed with penile excision, which did not affect the postoperative appearance. This did not affect the pathological analysis. The DR of lymph nodes in the 12HBS group was higher (p < 0.05) than that in the control group. More lymph nodes were removed for examination (p < 0.05), which improved the efficiency of surgery. Compared with the 12HBS group, the number of lymph nodes removed in the 0.5HBS group decreased (p < 0.05). The OT was shortened (p < 0.05), but there was no significant difference in the DR and PROLM.

Conclusion

CNSI was applied to the naked-eye tracing of inguinal sentinel lymph nodes in penile cancer, which is safe and efficient. Injection of CNSI 0.5 h before surgery can help identify the "foremost position" of sentinel lymph nodes and reduce surgical trauma.

A Preoperative Scoring System to Predict the Risk of Inadequate Lymph Node Count in Rectal Cancer

Purpose

The aim of this study was to develop and validate a preoperative scoring system to stratify rectal cancer (RC) patients with different risks of inadequate lymph node examination.

Methods

A total of 1,375 stage I–III RC patients between 2011 and 2020 from the Second Affiliated Hospital of Harbin Medical University were included in the retrospective study and randomly divided into a development set (n = 688) and a validation set (n = 687). The logistic regression model was used to determine independent factors contributing to lymph node count (LNC) < 12. A preoperative scoring system was constructed based on beta (β) coefficients. The area under the receiver operating curve (AUC) was used to test model discrimination.

Results

Preoperative significant indicators related to LNC < 12 included age, tumor size, tumor location, and CEA. The AUCs of the scoring system for development and validation sets were 0.694 (95% CI = 0.648–0.741) and 0.666 (95% CI = 0.615–0.716), respectively. Patients who scored 0–2, 3–4, and 5–6 were classified into the low-risk group, medium-risk group, and high-risk group, respectively.

Conclusions

The preoperative scoring system could identify RC patients with high risk of inadequate lymphadenectomy accurately and further provide a reference to perform preoperative lymph node staining in targeted patients to reduce the difficulty of meeting the 12-node standard, with the purpose of accurate tumor stage and favorable prognosis.

Lymph Node Cluster Dissection After Carbon Nanoparticles Injection Enhances the Retrieval Number in Colorectal Cancer

For colorectal cancer patients, NCCN recommended that at least 12 lymph nodes should be detected since the number and metastases status of lymph nodes played an important role in the treatment and prognostic. Carbon nanoparticles have been proved to be an efficient lymph node tracer. Faced with the clinical problem of insufficient lymph nodes in colorectal cancer, we proposed a lymph node cluster (D3, D2 and D1) dissection method combined with carbon nanoparticle injection. In our study, patients were divided into 2 groups (CNP and control). All lymph nodes of each patient were collected and made into hematoxylin-eosin sections to observe their size, staining appearance and metastasis status under the microscope. As a result, the total lymph nodes in CNP group were greatly higher than control group (51.45 vs. 29.62, P = 0.000), especially micro LNs and positive micro LNs. Compared with D2 and D1 stations, fewer lymph nodes were found in D3, and it was the same for cancer metastasis status. In CNP group, most lymph nodes got black for quick visualization. In conclusion, lymph node cluster dissection combined with carbon nanoparticles could enhance the number of lymph node retrieval.

Application of Carbon Nanoparticles in Tracing Lymph Nodes and Locating Tumors in Colorectal Cancer: A Concise Review

Background

Accurate lymph node (LN) staging has considerably prognostic and therapeutic value in patients with colorectal cancer (CRC). The purpose of this study is to evaluate the feasibility of applying carbon nanoparticles (CNPs) to track LN metastases in CRC.

Methods

Two researchers independently screened publications in PubMed, EMBASE, Cochrane and Ovid MEDLINE databases. The keywords were (carbon nanoparticles OR activated carbon nanoparticles) AND (colon cancer OR rectal cancer OR colorectal cancer). Titles and abstracts of the articles were meticulously read to rule out potential publications. Next, full texts of the ultimately obtained eligible publications were retrieved and analyzed in detail.

Results

The search produced 268 publications, and 140 abstracts were identified after a bibliographic review. Finally, 20 studies relevant to our subject were obtained; however, only 14 papers met our inclusion criteria and were included for final review. All studies included have compared the control group with carbon nanoparticles group (control group, defined as nontattooed group; and carbon nanoparticles group, defined as administering carbon nanoparticles during surgery) for their efficacy in intraoperative detecting and positioning. After analysis, appreciably less amount of bleeding (3/5 trials), shorter operation time (2/4 trials), and shorter time to detect lesions and dissect LNs (2/2 trials) were revealed in CNPs group compared to control group. Thirteen studies have recorded the numbers of the harvested LNs in both groups; meanwhile, CNPs group shows superiority to control group in LN retrieval as well (11/13 trials), which also could effectively aid in locating and harvesting more LNs with diameter below 5 mm.

Conclusion

The tracing technique for CNPs is a safe and useful strategy both in localizing tumor and tracing LNs in CRC surgery. But there is still a need for more randomized controlled trials to further establish its contribution to patient survival.

Clinical application of carbon nanoparticles in lymphatic mapping during colorectal cancer surgeries: A systematic review and meta-analysis

OBJECTIVE

To investigate the overall performance of carbon nanoparticles (CNs) for detecting lymph nodes (LNs) and node metastasis during colorectal cancer surgery.

METHODS

The English and Chinese literature was searched until 29 April 2020. Studies were included if they were randomized controlled trials (RCTs) for colorectal resection and LN dissection that compared the use of CNs with a blank control in colorectal cancer surgery. Quality assessment and data extraction were performed, and a meta-analysis was conducted using ReviewManager 5.3 and Stata 15.1 software.

RESULTS

A total of 17 RCTs comprising 1241 patients were included for analysis. Compared with the outcomes of the blank controls, the use of CNs resulted in an average of 5.21 more LNs per patient (weighted mean difference = 5.21, 95% confidence interval [CI] = 4.14-6.29, p < 0.001) and a 68% higher detection rate of micro LNs (relative risk [RR] = 1.68, 95% CI = 1.38-2.04, p < 0.001). In addition, more metastatic LNs were identified in stained nodes (RR = 1.56, 95% CI = 1.40-1.75, p < 0.001), but the total detection rate of metastatic nodes did not differ between the groups.

CONCLUSION

CN is an effective lymphatic tracer in colorectal cancer surgeries. Further studies with larger sample sizes are needed to validate these findings.

The safety and effectiveness of carbon nanoparticles suspension in tracking lymph node metastases of colorectal cancer: a prospective randomized controlled trial

OBJECTIVE

This study was to evaluate the safety and effectiveness of carbon nanoparticles suspension in tracking lymph node metastases of colorectal cancer.

METHODS

Eligible patients diagnosed with stages I-III colorectal cancer in Fudan University Shanghai Cancer Center between 1 May 2017 and 31 May 2018 fulfilling the inclusion criteria were included in this prospective randomized controlled study. All the patients were randomly allocated to two groups: the nanocarbon group and the control group. Patients' clinicopathological characteristics were compared between the nanocarbon group and the control group. For continuous variables, data were presented as mean (±SD) and differences between the two groups were compared by the Mann-Whitney U test; for categorical variables, data was presented as frequency (%) and the Pearson's chi-squared test was used to compare the differences between two groups.

RESULTS

All the patients' characteristics between two groups did not achieve statistical significance (P > 0.05). Patients in nanocarbon group were more likely to be associated with more lymph nodes retrieved totally compared with control group (19.84 ± 6.428 vs. 17.41 ± 7.229, P < 0.001). The number of lymph nodes retrieved in nanocarbon group were more likely to be ≥12 than that in the control group (P = 0.005).

CONCLUSIONS

Our study confirmed the safety of using carbon nanoparticles suspension as a tracer in colorectal cancer. More importantly, nanocarbon could significantly increase the detected number of lymph nodes in colorectal cancer, which can help improve the accuracy of lymph node staging and even improve patients' survival.

Comparison of indocyanine green and carbon nanoparticles in endoscopic techniques for central lymph nodes dissection in patients with papillary thyroid cancer

BACKGROUND

Injection of carbon nanoparticle (CN) into the thyroid gland is used to stain CLNs in endoscopic surgery of patients with papillary thyroid cancer (PTC). The black-dye technique facilitates the central lymph nodes (CLNs) harvest and parathyroid protection, but improper handling of CN during injection leads to unwanted staining of surrounding tissues and increases the difficulty in anatomical identification. Therefore, a new method is needed to overcome this problem.

METHODS

Forty-eight patients with PTC underwent endoscopic thyroidectomy via breast approach. Patients were randomized into the indocyanine green (ICG) group (Group ICG; n = 23) and CN group (Group CN; n = 25). After thyroid gland exposure, ICG was injected into the thyroid lobes. Fluorescent CLNs were identified and dissected in Group ICG. In Group CN, CN was used instead. Black dyed CLNs were harvested. The following was compared between groups: demographic characteristics, surgical time, drainage amount, hospital stay duration, number of CLNs harvested, frequency of postoperative hoarseness and hypothyroidism, and surgical cost.

RESULTS

Group ICG showed decreased hypoparathyroidism frequency than Group CN (1/23 vs. 7/25, p = 0.028) and more harvested CLNs (4.6 ± 1.0 vs. 3.8 ± 1.2, p = 0.020). There was no difference between drainage amount, hospital stay duration, and frequency of postoperative hoarseness. The cost of Group ICG was less than that of Group CN (p = 0).

CONCLUSION

Injection of ICG into the thyroid gland using fluorescence imaging in endoscopic surgery in patients with PTC is safer and more effective in identifying CLNs than injection with CN. This novel method can lead to improved identification and subsequent harvesting of CLNs.