Indocyanine Green Tattooing During Colonoscopy as a Guide to Laparoscopic Colorectal Cancer Surgery: A Literature Review

BACKGROUND

Endoscopic tattooing of colorectal lesions has been performed employing several markers. The indocyanine green (ICG) that uses near infrared fluorescence technology, has been recently adopted in laparoscopic colorectal cancer surgery. This study aims to systematically review the international literature to validate the ICG in laparoscopic colorectal surgery, in order to include the ICG in the therapeutic protocol.

METHODS

Following AMSTAR 2 criteria, we performed a systematic review to evaluate the use of green indocyanine as a marker for preoperative endoscopic tattooing and for lymph nodes mapping. The study selection was conducted using the PubMed database from January 1989 to July 2022.

RESULTS

We identified 25 eligible studies. 13 based on fluorescent tumor localization in laparoscopic colorectal surgery using ICG while 12 of them reported the lymphatic road mapping and sentinel node identification by ICG using a near-infrared camera system. One study analyzed both topics.

CONCLUSIONS

In laparoscopic colorectal cancer surgery indocyanine green can be used to localize fluorescent tumors and mapping fluorescence lymph node. The use of ICG appears to be a valid and safe technique that helps the surgeon to achieve a better oncological radicality. However, the protocols need to be clarified by further studies.

Factors Affecting the Efficiency of Near-Infrared Indocyanine Green (NIR/ICG) in Lymphatic Mapping for Colorectal Cancer: A Systematic Review

As laparoscopy gained global popularity in oncologic surgery, the challenge of detecting lymph nodes spurred researchers to explore innovative techniques and approach the situation from a fresh perspective. While many proposed methods have faded into obscurity, the utilization of indocyanine green (ICG) in the surgical treatment of oncologic patients has continued to advance. The immense potential of this dye is widely acknowledged, yet its full extent and limitations in lymphatic mapping for colorectal cancer remain to be precisely determined. This article aims to assess the magnitude of its potential and explore the constraints based on insights from clinical studies published by pioneering researchers. A systematic review of the existing literature, comprising articles in English, was conducted using the Scopus, PubMed, and Springer Link databases. The search employed keywords such as "colorectal cancer" AND/OR "indocyanine green," "fluorescence" AND/OR "lymphatic mapping" AND/OR "lymph nodes." Initially identifying 129 articles, the application of selection criteria narrowed down the pool to 10 articles, which served as the primary sources of data for our review. Despite the absence of a standardized protocol for the application of ICG in colorectal cancer, particularly in the context of lymphatic mapping, the detection rates have exhibited considerable variation across studies. Nevertheless, all authors unanimously regarded this technique as beneficial and promising. Additionally, it is advocated as an adjunctive tool to enhance the accuracy of cancer staging. Near-infrared (NIR)-enhanced surgery holds the promise of transforming the landscape of oncologic surgery, emerging as a valuable tool for surgeons. However, the absence of a standardized technique and the subjective nature of result assessment impose limitations on the potential of this method. Consequently, it can be inferred that the establishment of a universally accepted protocol, encompassing parameters such as dose, concentration, technique, and site of administration of ICG, along with the optimal time needed for fluorescence visualization, would enhance the outcomes. Emphasizing the accurate selection of patients is crucial to prevent the occurrence of false-negative results.

Role of Nuclear Sentinel Lymph Node Mapping Compared to New Alternative Imaging Methods

With the emergence of sentinel node technology, many patients can be staged histopathologically using lymphatic mapping and selective lymphadenectomy. Structural imaging by using US, CT and MR permits precise measurement of lymph node volume, which is strongly associated with neoplastic involvement. Sentinel lymph node detection has been an ideal field of application for nuclear medicine because anatomical data fails to represent the close connections between the lymphatic system and regional lymph nodes, or, more specifically, to identify the first draining lymph node. Hybrid imaging has demonstrated higher accuracy than standard imaging in SLN visualization on images, but it did not change in terms of surgical detection. New alternatives without ionizing radiations are emerging now from "non-radiological" fields, such as ophthalmology and dermatology, where fluorescence or opto-acoustic imaging, for example, are widely used. In this paper, we will analyze the advantages and limits of the main innovative methods in sentinel lymph node detection, including innovations in lymphoscintigraphy techniques that persist as the gold standard to date.

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.

Advances in surgical techniques for gastric cancer: Indocyanine green and near-infrared fluorescence imaging. Is it ready for prime time?

Surgery is still the primary curative treatment for gastric cancer, which includes resection of the tumor with adequate margins and extended lymphadenectomy. In order to improve the operative results and the quality of life of patients, several endeavors have been made toward precision medicine through image-guided surgery, allowing access to real-time intraoperative anatomy and accurate tumor staging. The goal of the surgeon is to achieve a more precise, individualized, and less invasive surgery without compromising oncological efficiency and safety. In this perspective, we have demonstrated the role of indocyanine green (ICG) and near-infrared (NIR) fluorescence imaging method in gastric cancer surgery. This technique may be used to improve localization of the tumor, detection of sentinel lymph nodes (SLN), real-time lymphatic mapping, and blood flow assessment (anastomosis perfusion).

Identification and Biopsy of Sentinel Lymph Node in Early-Stage Cervical Carcinoma: Diagnostic Accuracy and Clinical Utility

Background Due to the subsequent complications of pelvic lymphadenectomy in patients with early-stage cervical cancer, the sentinel lymph node (SLN) technique has been increasingly employed. This study aimed to investigate the detectability of SLN using methylene blue and explore the diagnostic accuracy of SLN biopsy. Methodology A study was conducted from September 2015 to August 2018 and included 90 women with cervical cancer, FIGO (International Federation of Gynecology and Obstetrics-2009) stage IA1-IIA1. Methylene blue was injected intracervically. Any detected dyed nodes were sent for frozen section biopsy, followed by bilateral pelvic lymphadenectomy. The predictive ability of SLN was evaluated in statistical terms after comparison of intraoperative biopsy and final histopathology. Results The sensitivity, specificity, false-negative rate, positive predictive value, and negative predictive value (NPV) were 55.6%, 95.1%, 4.9%, 55.6%, and 95.1%, respectively. The SLN performance in patients with tumor size ≤2.2 cm, negative lymphovascular space involvement, and depth of stromal invasion ≤5 mm was superior (sensitivity 100%, specificity 93.5%, NPV 100%). Conclusions The SLN technique with blue dye alone is a feasible and adequate alternative to systematic lymphadenectomy in early-stage cervical cancer in selected patients, given that a strict algorithm is applied.

ICG-Guided Lymphadenectomy during Surgery for Colon and Rectal Cancer-Interim Analysis of the GREENLIGHT Trial

Lymphadenectomy is crucial for an optimal oncologic resection of colon and rectal cancers. However, without a direct visualization, an aberrant route of lymph node (LN) diffusion might remain unresected. Indocyanine-green (ICG) lymphatic mapping permits a real-time LNs visualization. We designed the GREENLIGHT trial to explore in 100 patients undergoing robotic colorectal resection the clinical significance of a D3 ICG-guided lymphadenectomy. The primary endpoint was the number of patients in whom ICG changed the extent of lymphadenectomy. We report herein the interim analysis on the first 70 patients. After endoscopic ICG injection 24 h (n = 49) or 72 h (n = 21) ahead, 19, 20, and 31 patients underwent right colectomy, left colectomy, and anterior rectal resection. The extent of lymphadenectomy changed in 35 (50%) patients, mostly (29 (41.4%)) for the identification of LNs (median two) outside the standard draining basin. Identification of such LNs was less frequent in rectal tumors that had undergone chemoradiotherapy (26.3%) (p > 0.05). A non-significant correlation between time-to-ICG injection and identification of aberrant LNs was observed (48.9% at 24 h vs. 23.8% at 72 h). The presence of LN metastases did not affect a proper fluorescent mapping. These data indicate that ICG lymphatic mapping provides relevant information in 50% of patients, thus increasing the accuracy of potentially curative resections.

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.

Superficial lymphatic drainage of the vulva and its relation to the regional nodes: an experimental study

BACKGROUND

Sentinel node biopsy in vulvar cancer is associated with much less morbidity than inguinofemoral node dissection. Our study focused on describing the morphology of superficial lymphatic drainage of the vulva and its relationship to regional nodes, which may facilitate orientation during surgery.

MATERIALS AND METHODS

In 24 female cadavers, injections of patent blue (at various localisations medially, unilaterally and bilaterally) were used to visualise the lymphatic drainage of the vulva. After dissection of lymphatic vessels and nodes, their course was documented by photograph and then analysed. Subsequently, a map of vulvar superficial lymphatics was created.

RESULTS

The cutaneous and subcutaneous tissue of the vulva primarily drained to superficial inguinal nodes. There was no evidence of a solitary lymph node that drained the unilateral vulva. Each area of the vulva drained to its own lymph node, which was variably localised in the subcutaneous groin around the great saphenous vein. Anastomoses between individual inguinal superficial lymph nodes are likely. Right-left symmetry in the course of lymphatic collectors was not detected. Natural drainage of the medial and paramedial areas to contralateral inguinal nodes was also not detected. The drainage pattern to ipsilateral inguinal nodes was consistent in cadavers without evidence of vulvar disease and may be applicable in the early stages of vulvar cancer.

CONCLUSIONS

There was no evidence of a solitary node that drained the unilateral vulva. Each part of the vulva may drain to a corresponding lymph node in a different localisation of the groin. The surgeon should take this variability into account.

Sentinel lymph node in cervical cancer: time to move forward

In early-stage cervical cancer, lymph node status is of paramount importance to determine the best therapeutic strategy and is one of the most important prognostic factors of survival. According to main international guidelines, pelvic full lymphadenectomy is recommended for lymph node staging. Sentinel lymph node (SLN) biopsy is an accurate method for the assessment of lymph nodal involvement and has been suggested instead of systematic pelvic lymph node dissection (PLND). The SLN technique requires a learning-curve to be well performed. Combined detection with technetium-99 and blue dye has been widely used but the recent introduction of indocyanine green (ICG) is of growing interest since it could improve SLN detection. SLN biopsy offers a more accurate anatomical staging by finding potential metastatic nodes outside of usual lymphadenectomy areas. SLN biopsy improves the diagnostic value of lymph node staging with ultrastaging and detection of low-volume nodal metastases [isolated tumor cells (ITCs) and micrometastases]. Appropriate selection of patient and minimal training combined with some simple rules may guarantee a low false negative rate. Several studies have shown that SLN mapping in these patients is feasible, with excellent detection rates and sensitivity. Less-radical lymph node dissection decreases the associated morbidity of PLND, especially the risk of lower-limb lymphoedema, which severely affects patient quality of life. Some points are still subject to debate such as the low accuracy of intraoperative SLN status assessment by frozen section and the impact of micrometastasis on prognosis. Although international guidelines consider SLN biopsy as an alternative to PLND, SLN biopsy alone is not the gold-standard yet due to lack of prospective evidence on long-term oncological safety. The 3 ongoing prospective trials SENTIX, PHENIX and SENTICOL III will most probably give an answer to these issues.

A single-center, self-controlled, phase I clinical trial of mitoxantrone hydrochloride injection for lymph tracing for sentinel lymph node identification of breast cancer

Background

Mitoxantrone hydrochloride injection for lymph tracing (MHI) is a novel lymphatic tracer for sentinel lymph node (SLN) in patients with early breast cancer but exhibited remarkable liver, kidney, and hematologic toxicities in previous studies. Here, the pharmacokinetics and pharmacodynamics profiles of MHI were evaluated to surmise safety and tolerability.

Methods

Phase 1 open-label, single center, and dose escalation study was performed. Ten patients with invasive breast cancer received 0.5, 1.0, or 2.0 mL of MHI into the breast tissues surrounding the tumor for lymphatic mapping. All of these patients were injected with 2 mCi nuclide-labeled sulfur colloid as a self-control 24 to 48 hours before surgery. Safety was assessed by the incidence of adverse events graded by the National Cancer Institute Common Terminology Criteria, version 4.0.3 (CTCAE4.0.3). Blood samples for pharmacokinetic analyses were collected before and after administration at 15, 30, 60, 120, and 240 min of the injection of MHI.

Results

Up to the cutoff date of the study (Aug 8, 2018), no dose-limiting toxic effects or obvious allergic reactions were observed. Only one case of an adverse event was certainly related to MHI, where it caused blue discoloration of the local skin over the injection site after the operation, but this stain gradually went away. The peak level of MHI was achieved after 15-30 min post injection and completely eliminated from the plasma after 60 min. There were no significant differences in the number of lymph nodes detected by MHI and radioactive colloid. Only one patient with lymph node macrometastases had no SLN detected by either the radioactive colloid or the MHI.

Conclusions

At a dose of up to 2.0 mL, MHI was well tolerated and safe for conducting SLN biopsies in patients with breast cancer. Although there was a case with blue discoloration of the local skin over the injection site after the operation, and remained for a short period of time, but the overall safety was acceptable. Here, we approached a novel SLN tracing slant; however, more investigations of MHI should be performed for further evaluations. (Chinadrugtrials.org.cn number: CXHL1301201, Date of registration: October 12, 2015.).

Anatomical basis of lymph node detection in gynecologic cancers: a review from a surgical perspective

Pelvic and para-aortic lymphadenectomy are associated with increased risk of complications and are responsible for a significant proportion of morbidity and impaired quality of life following surgical management of pelvic malignancies. Sentinel lymph node (SLN) was developed as a trade-off between systematic and no lymphadenectomy to limit morbidity while conserving good oncological staging and outcomes. In this comprehensive review, we aimed to synthetize the anatomical basis of the SLN procedure in patients with pelvic malignancies from a surgical perspective. The reliability of the SLN procedure is based on the knowledge of the dissemination pathways for each type of tumors. The most recent understanding of the uterine lymphatic anatomy defined three consistent channels: an upper paracervical pathway (UPP) with draining medial external and/or obturator lymph nodes; a lower paracervical pathway (LPP) with draining internal iliac and/or presacral lymph nodes and the infundibulo-pelvic pathway (IPP) with a course along the fallopian tube and upper broad ligament via the infundibulo-pelvic ligament to its origin. In patients with endometrial cancer, most SLNs are located on the UPP pathway: obturator and external iliac whereas 80% of the SLNs in patients with cervical cancer are located in the external iliac, interiliac and obturator area. Surgical training is a key step toward improving detection rates and exhaustiveness of SLN research while reducing overall morbidity. This is all the more important that the indications for performing complete lymphadenectomy are becoming increasingly rare.

Sentinel lymph node detection differs when comparing lymphoscintigraphy to lymphography using water soluble iodinated contrast medium and digital radiography in dogs

Sentinel lymph node (SLN) mapping by various means has become standard of care in certain types of human cancers and is receiving more attention in veterinary oncology. Current SLN mapping techniques can be costly and often require advanced imaging equipment. The objective of this prospective, method comparison study was to compare an SLN mapping protocol of lymphoscintigraphy to lymphography using water soluble iodinated contrast medium (WIC) and digital radiography for identification of an SLN. Lymphoscintigraphy and lymphography were performed on eight healthy purpose-bred dogs using technetium-99m sulfur colloid and WIC injected into the subcutaneous tissues in a four-quadrant technique around a predefined area of skin on the brachium. Images were obtained using a gamma camera and digital radiography at different time points post-injection. Image sequences were evaluated by one of two American College of Veterinary Radiology board-certified veterinary radiologists. Data obtained were compared between methods using descriptive statistics. An SLN was identified in all dogs with lymphoscintigraphy and seven of eight dogs with lymphography. Agreement between results of the lymphoscintigraphy and lymphography studies was a complete match in three dogs, a partial match in four dogs, and no match in one dog. The SLN detected differed based on the imaging modality used.

Key clinical applications for indocyanine green fluorescence imaging in minimally invasive colorectal surgery

Near-infrared indocyanine green (ICG) fluorescence imaging has gained solid acceptance over the last years, and rightly so, as this technology has so much to offer, especially in the field of minimally invasive surgery. Firm evidence from ongoing and future studies will hopefully transform many of the applications of ICG fluorescence into the standard of care for our patients. This review examines the current status of ICG fluorescence for assessment of bowel perfusion, lymphatic mapping as well as intraoperative localisation of ureter in light of the published academic literature in English.

Cryo-Assisted Resection En Bloc, and Cryoablation In Situ, of Primary Breast Cancer Coupled With Intraoperative Ultrasound-Guided Tracer Injection: A Preliminary Clinical Study

The aim of the study was to perform cryosurgery on a primary breast tumor, coupled with simultaneous peritumoral and intratumoral tracer injection of a blue dye, to evaluate lymphatic mapping. We explored the ability of our strategy to prevent tumor cells, but not that of injected tracers, to migrate to the lymphovascular drainage during conventional resection of frozen breast malignancies. Seventeen patients aged 51 (14) years (mean [standard deviation]), presenting primary breast cancer with stage I to IV, were randomly selected and treated in The Rudolfinerhaus Private Clinic in Vienna, Austria, and included in this preliminary clinical study. Under intraoperative ultrasound, 14 patients underwent curative cryo-assisted tumor resection en bloc, coupled with peritumoral tracer injection, which consisted of complete tumor freezing and concomitant peritumor injection with a blue dye, before resection and sentinel lymph node dissection (group A). Group B consists of 3 patients previously refused any standard therapy and had palliative tumor cryoablation in situ combined with intratumoral tracer injection. The intraoperative ultrasound facilitated needle positioning and dye injection timing. In group A, the frozen site extruded the dye that was distributed through the unfrozen tumor, the breast tissue, and the resection cavity for 12 patients. One to 4 lymph nodes were stained for 10 of 14 patients. The resection margin was evaluable. Our intraoperative ultrasound-guided performance revealed the injection and migration of a blue dye during the frozen resection en bloc and cryoablation in situ of primary breast tumors. Sentinel lymph node mapping, pathological determination of the tumor, and resection margins were achievable. The study paves the way for intraoperative cryo-assisted therapeutic strategies for breast cancer.

Outcomes of "one-day" vs "two-day" injection protocols using Tc-99m tilmanocept for sentinel lymph node biopsy in breast cancer

No prior studies have compared Tc-99m tilmanocept (TcTM) one-day and two-day injection protocols for sentinel lymph node (SLN) biopsy in breast cancer (BC). We retrospectively identified patients with clinically node-negative BC undergoing SLN biopsy at our institution. Patients received a single, intradermal peritumoral injection of TcTM on day of surgery or day prior to surgery in addition to an intraoperative injection of isosulfan blue dye. Univariable and multivariable Poisson regression count models were constructed to assess the effects of injection timing, radiologist, patient and surgeon characteristics on the number of removed SLNs. A total of 617 patients underwent SLN biopsy with TcTM and blue dye. Sixty-seven (10.9%) patients were injected with the two-day protocol. Patients in the one-day protocol had a mean of 3.0 (standard deviation (SD) 1.9) SLNs removed compared with 2.7 (SD 1.4) SLNs in the two-day protocol, P-value = .13. On multivariable analysis, patient age and operating surgeon significantly affected the number of removed SLNs; however, the injection timing and the nuclear radiologist did not influence the number of removed SLNs. The performance of Tc-99m tilmanocept did not differ significantly between one-day and two-day injection protocols. These results are similar to other radiotracers used for SLN biopsy in BC.

A pilot study of lymph node mapping with indocyanine green in robotic gastrectomy for gastric cancer

OBJECTIVES

Robotic gastrectomy has become increasingly popular in the treatment of gastric cancer, especially in Asian countries. The use of indocyanine green fluorescence has been reported in lymphatic mapping for gastric cancer in laparoscopic gastrectomy; however, there have been few reports regarding the use of indocyanine green in robotic gastrectomy.

METHODS

From January 2011 to March 2016, a total of 79 patients underwent robotic gastrectomy for gastric cancer. Among them, intraoperative subserosal injection (n = 9) or preoperative submucosal injection (n = 5) of indocyanine green with near-infrared imaging was performed in 14 patients, and the other 65 patients underwent robotic gastrectomy without the use of indocyanine green.

RESULTS

There was no significant difference in the operative time, total number of retrieved lymph nodes, operative blood loss, and postoperative hospital stay between the patients who underwent robotic gastrectomy with or without indocyanine green fluorescence. For each lymph node station, there was significantly more number of retrieved lymph nodes in the indocyanine green group than in the no-indocyanine green group at the greater curvature side of the low body (#4d) to the infrapyloric region (#6) of the stomach. Five of the 14 patients who received an indocyanine green injection for lymphatic mapping had lymph node metastasis, and metastatic lymph nodes were located in the lymph node stations as detected by indocyanine green fluorescence during surgery.

CONCLUSION

Indocyanine green fluorescence with near-infrared imaging is feasible and is a promising method of lymphatic mapping in robotic gastrectomy for gastric cancer. In future studies, larger patient numbers and long-term follow-up are required.

Use of 99mTc-Tilmanocept as a Single Agent for Sentinel Lymph Node Identification in Breast Cancer: A Retrospective Pilot Study

^99mTc-tilmanocept received recent Food and Drug Administration approval for lymphatic mapping in 2013. However, to our knowledge, no prior studies have evaluated the use of ^99mTc-tilmanocept as a single agent in sentinel lymph node (SLN) biopsy in breast cancer. Methods: We executed this retrospective pilot study to assess the ability of ^99mTc-tilmanocept to identify sentinel nodes as a single agent in clinically node-negative breast cancer patients. Patients received a single intradermal injection overlying the tumor of either 18.5 MBq (0.5 mCi) of ^99mTc-tilmanocept on the day of surgery or 74.0 MBq (2.0 mCi) on the day before surgery by a radiologist. Immediate 3-view lymphoscintigraphy was performed. Intraoperatively, SLNs were identified with a portable γ-probe. A node was classified as hot if the count (per second) of the node was more than 3 times the background count. Descriptive statistics are reported. Results: Nineteen patients underwent SLN biopsy with single-agent ^99mTc-tilmanocept. Immediate lymphoscintigraphy identified at least 1 sentinel node in 13 of 17 patients (76.5%). Intraoperatively, at least 1 (mean, 1.7 ± 0.8; range, 1-3) hot node was identified in all patients. Three patients (15.8%) had 1 disease-positive SLN. Conclusion: In this small, retrospective pilot study, ^99mTc-tilmanocept performed well as a single agent for intraoperative sentinel node identification in breast cancer. A larger, randomized clinical trial is warranted to compare ^99mTc-tilmanocept as a single agent with other radiopharmaceuticals for sentinel node identification in breast cancer.

Tc-99m tilmanocept versus Tc-99m sulfur colloid in breast cancer sentinel lymph node identification: Results from a randomized, blinded clinical trial

INTRODUCTION

No prior trials have compared sentinel lymph node (SLN) identification outcomes between Tc-99m tilmanocept (TcTM) and Tc-99m sulfur colloid (TcSC) in breast cancer (BC).

METHODS

We report on the secondary outcomes from a randomized, double-blinded, single surgeon clinical trial comparing post-injection site pain between TcTM and TcSC. Patients were randomized to receive a preoperative single, peritumoral intradermal injection of TcTM or TcSC. The number of total, "hot", and blue nodes detected and removed were compared between groups.

RESULTS

Fifty-two (27-TcSC and 25-TcTM) patients were enrolled and underwent definitive surgical treatment. At least one "hot" SLN was detected in all patients. Three (5.8%) patients had a disease positive-SLN. The total number of SLNs removed was 61 (mean 2.26 (standard deviation (SD) 0.90)) in the TcSC group and 54 (mean 2.16 (SD 0.90)) in the TcTM group, P = 0.69. The total number of "hot" nodes in the TcSC group was 1.96 (SD 0.76) compared to 2.04 (SD 0.73) in the TcTM group, P = 0.71.

CONCLUSIONS

The number of identified SLNs did not differ significantly between TcTM and TcSC. Given that no significant technical advantages exist between the two agents, surgeons should choose a radiopharmaceutical based on cost and side effect profile.

Lymphatic mapping and sentinel node biopsy in a patient with upper limb Merkel Cell Carcinoma: a case report and brief review of literature

Sentinel node mapping is an integral part of regional lymph node staging in many solid tumors and plays an important role in surgical oncology. This technique has been used with excellent results for non-melanoma skin cancers including Merkel Cell Carcinoma (MCC). In the current study, we reported our first MCC patient who underwent successful sentinel node mapping. We also reviewed the available literature regarding the prognostic significance of sentinel node mapping in cN0 MCC patients.

Utility of sentinel lymph node biopsy for thyroid cancer: a comprehensive review

Sentinel lymph node biopsy (SLNB) is a minimally invasive lymphatic mapping technique, used to identify lymph node micrometastases and stage multiple cancer types. Despite the performance of SLNB for thyroid cancer having been under study since 1998, its role has remained controversial. The objective of this review is to summarize current research reporting on SLNB for thyroid cancer, focusing on recent studies of its application to differentiated thyroid cancer. The technique and potential benefits of SLNB are reviewed with regards to its ability to identify lymph node metastases, aid in cancer prognostication, and direct surgical and medical treatment.

Lymphatic mapping in the treatment of chronic seroma: a case series

OBJECTIVE

Seromas or lymphoceles are common postoperative complications. This series presents 3 patients with lower extremity seromas refractory to treatment that required lymphatic mapping and lymphatic ligation for closure, and in 1 case, diagnosis.

METHODS

Lymphatic mapping procedure consisted of intraoperative injection of subcutaneous tissue with methylene blue distal to the seroma with observation of dye effluence from transected or injured lymphatics draining into area of seroma.

RESULTS

In 2 patients, methylene blue dye absorption into lymphatic vessels allowed for optimized visual identification of lymphatic leak and contrast against surrounding tissues. In the third patient, where no lymphocele leak was found, the study was diagnostic and helped to find an alternate etiology for the recurrent seroma.

CONCLUSION

Lymphatic mapping with methylene blue dye is an effective tool in the evaluation and diagnosis of chronic seroma.

Axillary reverse mapping in breast cancer: a Canadian experience

BACKGROUND

The aim of this study was to evaluate the axillary reverse lymphatic mapping (ARM) procedure for reducing the risk of arm lymphedema after breast cancer surgery.

METHODS

The ARM procedure was carried out with a subareolar injection of technetium-99 sulfur colloid the morning of surgery, and a patent blue dye injection into the upper inner arm after anesthesia.

RESULTS

Fifty-two women made up our study population. Thirty-seven patients underwent sentinel lymph node biopsy (SLNB) and 15 patients underwent an axillary lymph node dissection (ALND) for known nodal metastasis. The sentinel lymph node was identified in 36 of the 37 cases who underwent SLNB alone and in 12 of 15 patients who underwent on ALND. In 13 patients, both blue and radioactive lymph nodes or lymphatics were clearly identified (25%) and 5 patients had a clear crossover with nodes being both blue and hot. Only a single patient with crossover lymphatics had metastases present in their sentinel node.

CONCLUSION

The ARM technique did not prevent identification of the SLN and we identified much greater crossover than reported. We had a single patient, who underwent a sentinel node biopsy, with mild arm lymphedema (1.9%) after 2 years of follow up.

Mapping lymph nodes in cancer management - role of (99m)Tc-tilmanocept injection

Two decades ago, lymphatic mapping of sentinel lymph nodes (SLN) was introduced into surgical cancer management and was termed sentinel node navigated surgery. Although this technique is now routinely performed in the management of breast cancer and malignant melanoma, it is still under investigation for use in other cancers. The radioisotope technetium (^99mTc) and vital blue dyes are among the most widely used enhancers for SLN mapping, although near-infrared fluorescence imaging of indocyanine green is also becoming more commonly used. ^99mTc-tilmanocept is a new synthetic radioisotope with a relatively small molecular size that was specifically developed for lymphatic mapping. Because of its small size, ^99mTc-tilmanocept quickly migrates from its site of injection and rapidly accumulates in the SLN. The mannose moieties of ^99mTc-tilmanosept facilitate its binding to mannose receptors (CD206) expressed in reticuloendothelial cells of the SLN. This binding prevents transit to second-echelon lymph nodes. In Phase III trials of breast cancer and malignant melanoma, and Phase II trials of other malignancies, ^99mTc-tilmanocept had superior identification rates and sensitivity compared with blue dye. Trials comparing ^99mTc-tilmanocept with other ^99mTc-based agents are required before it can be routinely used in clinical settings.

CASE REPORT Treatment of a Lower Extremity Lymphocele With Intraoperative Lymphatic Mapping

OBJECTIVE

Lower extremity lymphoceles secondary to saphenous vein grafting are exceptionally rare and there is only 1 previously reported case in the English literature. Data on treatment of lower extremity lymphoceles are limited and based on studies of groin lymphoceles. We discuss operative resection with selective ligation of feeding lymphatic vessels as a treatment option of lower extremity lymphoceles.

METHODS

A 64-year-old man who had undergone coronary artery bypass grafting 6 years prior presented with a left lower extremity mass at the site where his saphenous vein had been harvested. Examination demonstrated a 12-cm, mobile, nonpulsatile mass at his medial left calf. The findings of magnetic resonance imaging were consistent with a lymphocele.

RESULTS

Intraoperative injection of isosulfan blue dye was used to identify feeding lymphatic vessels and the lymphocele cavity was excised. Leg drains were discontinued after 3 days, and the patient was discharged home after 6 days.

CONCLUSION

Operative resection with isosulfan blue dye lymphatic mapping and selective ligation of lymphatic vessels is a viable treatment of lower extremity lymphoceles.

Sentinel lymph node mapping and biopsy using radioactive tracer in gastric cancer

BACKGROUND

Lymph node metastasis is one of the most important prognostic factors in gastric cancer survival. Sentinel lymph node (SLN) mapping and biopsy may reduce the extension of lymph node dissection by determination of lymph node involvement. The current study prospectively evaluates the feasibility and reliability of SLN biopsy in gastric cancer.

METHODS

A total of 30 patients with gastric cancer with a preoperative imaging stage of T1-T2 or T3, N0 and M0 were enrolled in the study. Furthermore, 2-16 h prior to each operation, (99m) Tc-sulphur colloid solution (0.5 mL, 2 mCi/mL) was endoscopically injected into the submucosal layer around the primary lesion. Lymph nodes were examined using a hand-held gamma probe. Subsequently, a total or subtotal gastrectomy and D2 lymphadenectomy was performed in each patient.

RESULTS

The success rate of SLN biopsy was 100%. Sensitivity, specificity, positive predictive value and negative predictive value were 91.7%, 100%, 100% and 75%, respectively. Both of the two false-negative cases were in the T3 group. In cases of T2 tumours, the sensitivity was 100%.

DISCUSSION

SLN biopsy using a gamma probe in early stage gastric cancer seems to be a safe, feasible and accurate procedure with high sensitivity in predicting regional lymph node involvement.

A new device for sentinel node detection in laparoscopic colon resection

OBJECTIVE

To test the feasibility of using a newly developed device for laparoscopic lymphatic mapping of the colon by simultaneous and quantitative detection of both tissue coloration and radioactivity.

METHODS

Four pigs were used in this study. In each animal, both blue dye and radioisotope injections were utilized. Lymphatic mapping was performed laparoscopically in the sigmoid mesocolon and in the right mesocolon. A solution containing a mix of 35 microcuries of Technetium Tc-99 sulfur Colloid and 1 mL of a vital blue dye was administered subserosally by percutaneous insertion of a 25 gauge needle under laparoscopic control. The new device for automated sentinel-node detection consists of a gamma-probe coupled with a laser device and can be passed through a regular 10-mm trocar. The device detects simultaneously both radioactivity and quantitative tissue coloration. Nodes showing a radioactivity at least 5 times higher than that of the background or that had a blue colorant concentration were considered our sentinel nodes.

RESULTS

Laparoscopic simultaneous and quantitative detection of sentinel nodes was feasible in all pigs. One or more sentinel nodes were identified by either the blue dye or radioisotopic technique in both the sigmoid and right mesocolon. Quantitative tissue coloration detection led to the recognition of additional nodes that were not apparently colored to the naked eye.

CONCLUSION

Laparoscopic sentinel node detection using a device combining gamma and color detection is feasible in the porcine model. The significance of nodes apparently clear but positive with the quantitative detection technique should be further evaluated.