A prospective comparative study to assess the contribution of radioisotope tracer method to dye-only method in the detection of sentinel lymph node in breast cancer

[Application of methylene blue near-infrared fluorescence imaging for oral sentinel lymph node mapping in rats]

OBJECTIVE

To explore the concentration range and penetration depth of methylene blue near-infrared fluorescence imaging, and to clarify the role of methylene blue in oral lymphatic drainage and sentinel lymph node localization, so as to lay a foundation for the potential research and application of sentinel lymph node in oral cancer.

METHODS

10% (mass fraction) methylene blue injection was diluted into 29 different concentrations with 0.9% (mass fraction) normal saline, and the concentration range of methylene blue near-infrared fluorescence imaging was determined by near-infrared fluorescence imager. The maximum penetration depth of methylene blue near-infrared fluorescence was determined by covering pigskin with different thicknesses (1, 2, 3, 4 and 5 mm) in methylene blue solution. 0.2 mL methylene blue solution was injected into the submucosal 0.5 cm at the lateral margin of tongue on one side of the rats. The near-infrared fluorescence imager was used for continuously monitoring for 3 hours. The first near-infrared fluorescence hotspot was identified as sentinel lymph node and labeled by percutaneous observation. The rats were then sacrificed and dissected in the head and neck. Near-infrared fluorescence imaging was performed again to observe whether the fluorescent tissue was consistent with the labeled fluorescent hotspot in vitro, and the presence of lymphoid tissue was confirmed by pathological examination after resection.

RESULTS

Except that no fluorescence signals were detected in the blank control groups, the fluorescence intensity of methylene blue increased first and then decreased with its solution concentration decreased. When the concentration of methylene blue was diluted to the picomole level, the fluorescence signal could still be detected. The maximum penetration depth of methylene blue fluorescence was 4 mm. Methylene blue near-infrared fluorescence could be localized in oral lymphatic drainage and sentinel lymph node. The fluorescence was sustained for more than 3 hours after methylene blue injection. Methylene blue solution concentrations of 3.34 mmol/L, 6.68 mmol/L, 13.37 mmol/L and 26.74 mmol/L were selected in the rats to map sentinel lymph node by near-infrared fluorescence.

CONCLUSION

Methylene blue near-infrared fluorescence has a certain penetrating ability and can transcuta-neously map the sentinel lymph node and their associated lymphatic vessels in rats, which is expected to be further applied in the study of sentinel lymph node in oral cancer.

Clinical study of combined application of indocyanine green and methylene blue for sentinel lymph node biopsy in breast cancer

OBJECTIVE

This study aims to investigate the feasibility of combined application of indocyanine green (ICG) and methylene blue (MB) for sentinel lymph node biopsy (SLNB) in patients with early breast cancer.

METHODS

A total of 415 patients who underwent SLNB and axillary lymph node dissection were enrolled. Sentinel lymph node (SLN) was assessed in 197 patients with ICG and MB combination method, while, the other 218 patients were detected by MB method alone. During surgery, all SLNs were harvested for pathological examination. Then the detection rate and false negative rate of SLNs were comparatively analyzed between the 2 groups.

RESULTS

In the combined ICG and MB group, the detection rate of SLNs was 96.9%, significantly higher than that of MB group, which was 89.7% (P < .05). Similarly, in combined group, the average number of SLNs per patient was 3.0, much higher than that of MB group, which was 2.1 (P < .05). There was no statistically significant difference in false negative rate between combined group and MB alone group, which was 7.3% and 10.5%, respectively (P = .791).

CONCLUSION

The combined application of ICG and MB for SLNB is much more effective than MB alone in detecting SLNs.

Comparison between sentinel lymph node hybrid scintigraphy and blue dye technique in breast cancer patients: An institutional experience

To compare the detection efficacy of radionuclide lymphoscintigraphy (LS) versus patent blue dye (PBD) technique for hidden sentinel lymph node (SLN) in breast cancer patients and to determine which modality is better for SLN detection. One hundred and thirty-four early stage breast cancer female patients with clinically negative axilla who underwent post technetium-99m nanocolloid injection single photon emission computed tomography (SPECT-CT) for negative SLN on planar imaging were studied prospectively between 2015 and 2017. Following SPECT-CT, patients underwent peroperative gamma probe count detection GP-CD and PBD technique. Visually, blue stained ± hot nodes were surgically removed and subjected to histopathological analysis. The detection rate by individual method was calculated. Kappa statistics were applied to calculate overall agreement between radioisotope and PBD techniques for diagnostic value assessment. One hundred and thirty-four patients underwent SPECT-CT LS and PBD injection. Mean age: 47 ± 7.6 years (range: 26–82 years). Forty-nine (36.6%) had T1 and 85 (63.4%) T2. SPECT-CT LS detected SLN in 105/134 cases (success rate: 78.4%), later GP-CD localized “hot nodes” in additional 20 cases (success rate: 93.3%). The PBD successfully localized SLN in 131/134 (97.8%) cases. Three cases remained negative on both radioisotope and PBD localization, which on subsequent nodal dissection had metastatic disease. All SLNs detected on SPECT-CT showed blue dye uptake. In 112 cases, more than one SLN was surgically removed. Frozen section analysis of excised SLNs showed metastasis in 31%. Overall moderate agreement (k = 0.56) was calculated. No statistically significant difference was seen between isotope detection and PBD. Radionuclide sentinel mapping has good detection rate particularly combined with peroperative GP-CD. The PBD has added value to reduce false-negative rate of SLN mapping and can substitute radionuclide imaging with negative results.

Sentinel lymph node biopsy mapped with methylene blue dye alone in patients with breast cancer: A systematic review and meta-analysis

Background

Methylene blue dye is easy to obtain in developing countries and can be used in sentinel lymph node mapping for breast cancer. However, the accuracy of methylene blue alone for sentinel lymph node mapping in breast cancer has not been well defined. In this study, we collected data to assess the feasibility and accuracy of sentinel lymph node biopsy mapped with methylene blue alone in patients with breast cancer.

Methods

We searched the PubMed, EMBASE, and Cochrane Library databases from January 1, 1993, to March 31, 2018. Selected studies had to have a defined group of patients with breast cancer in which MBD alone was used as the mapping technique for SNB.

Results

18 studies were included in this study. The combined identification rate was 91% [95% confidence interval (CI): 88%-94%, I² = 68.3%], and the false negative rate was 13% (95% CI: 9%-18%, I² = 36.7%). The pooled sensitivity, negative predictive value, and accuracy rate were 87% (95% CI: 82%-91%, I² = 37.5%), 91% (95% CI: 87%-93%, I² = 32.4%) and 94% (95% CI: 92%-96%, I² = 29%), respectively.

Conclusions

This meta-analysis found that mapping sentinel lymph node locations with methylene blue dye alone results in an acceptable identification rate but an excessive false negative rate according to the American Society of Breast Surgeons’ recommendations. Caution is warranted when using methylene blue dye alone as the mapping method for sentinel lymph node biopsy.

Comparison of sentinel lymph node biopsy guided by indocyanine green, blue dye, and their combination in breast cancer patients: a prospective cohort study

BACKGROUND

Recent studies show that near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has the potential to improve the performance of sentinel lymph node (SLN) mapping. The current cohort study was designed to assess the value of the combination of ICG and methylene blue (MB) dye in patients undergoing SLN biopsy.

METHODS

A prospective self-controlled trial was designed to detect the difference in the detection efficacies of ICG, MB, and combined ICG and MB (ICG + MB) navigation methods. Between 2010 and 2013, 198 consecutive early breast cancer patients eligible for sentinel lymph node biopsy were enrolled and 200 biopsy procedures were performed by injection of both ICG and MB. SLNs were searched and removed under the guidance of fluorescence and/or blue dye. The mapping characteristics, the detection rate of SLNs and positive SLNs, and the number of SLNs of ICG, MB, and ICG + MB were compared. Injection safety of ICG and MB was evaluated.

RESULTS

Fluorescence imaging of lymphatic flow, which is helpful to locate the incision site, could be seen in 184 of 200 procedures. The nodal detection rate of ICG, MB, and ICG + MB samples was 97, 89, and 99.5% (χ 2 = 26.2, p < 0.001), respectively, with the combination method yielding a superior identification result. The addition of ICG to the MB method resulted in the identification of more lymph nodes (median 3 versus 2) and more positive axillas (22.7% involved axillas were discovered by fluorescence only) than either method alone. No acute or chronic allergic reaction was observed in this study. However, 23 patients (23/82) who received breast-conserving therapy reported temporary skin staining, and 5 patients had permanent tattooing. Palpable subcutaneous nodules at the injection sites were reported in nine patients. There were no reports of skin necrosis.

CONCLUSIONS

The lymphatic navigation by ICG fluorescence detects SLNs at a high detection rate and improves the mapping performance when added to the MB method. The novel ICG + MB dual tracing modality, without involvement of radioactive isotopes, exhibits great potential as an alternative to traditional standard mapping methods.

TRIAL REGISTRATION

ACTRN12612000109808 . Retrospectively registered on 23 January 2012.

Quantitative assessment of visual estimation of the infrared indocyanine green imaging of lymph nodes retrieved at sentinel node navigation surgery for gastric cancer

Background

Although the infrared indocyanine green (ICG) imaging is an effective method to identify sentinel lymph nodes (SLNs) of gastric cancer, its objectivity has not been verified.

Methods

We studied 563 lymph nodes under infrared light observation from the ICG-positive lymphatic basins of 36 patients who underwent SLN-navigated gastrectomy for clinically node-negative gastric cancer. First, the rate of SLN detection, the number of SLNs and sensitivities were compared between ordinary light observation and infrared light observation. Second, 563 lymph nodes were grouped into ICG-positive and -negative under infrared light observation. The intensities of the region of interest for each lymph node defined as the lymph node on which digital imaging was performed using an imaging-software, and the region of reference defined as its surrounding background, were compared and quantified.

Results

In the comparison of ordinary light observation with infrared light observation, the SLN identification rates were 28/36 (78 %) vs. 36/36 (100 %), the mean ± SD (minimum to maximum) number of SLNs was 3.4 ± 3.7 (0–16) vs. 9.2 ± 5.9 (2–25), and the sensitivities were 1/5 (20 %) vs. 5/5 (100 %). The ICG-positive group contained 358 lymph nodes with an intensity of 0.323 ± 1.56 (mean ± SD), and the ICG-negative group contained 205 lymph nodes with an intensity of 0.639 ± 1.93 (mean ± SD), demonstrating a significant difference between these two groups (P < 0.0001).

Conclusions

The significant difference in the intensity as measured by an imaging-software between ICG-positive and ICG-negative lymph nodes would erase the concern about the objectivity of the infrared ICG method for SLN-navigated surgery for early gastric cancer.

Feeling blue, going green and finding other attractive alternatives: a case of biphasic anaphylaxis to patent blue and a literature review of alternative sentinel node localisation methods

Patent blue dye is used for sentinel lymph node localisation in order to stage the axilla in patients with breast cancer. Patent blue is one of the most common dyes used across the UK, however, the incidence of adverse effects seems to be increasing. This case highlights our experience of a biphasic anaphylactic reaction to patent blue dye, and we conduct a brief literature review of alternative and more novel methods to adequately visualise the lymphatics for sentinel lymph node biopsy.