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

Use of Indocyanine Green for Sentinel Lymph Node Biopsy: Case Series and Methods Comparison

Introduction:

Sentinel lymph node biopsy is indicated for patients with biopsy-proven thickness melanoma greater than 1.0 mm. Use of lymphoscintigraphy along with vital blue dyes is the gold standard for identifying sentinel lymph nodes intraoperatively. Indocyanine green (ICG) has recently been used as a method of identifying sentinel lymph nodes. We herein describe a case series of patients who have successfully undergone ICG-assisted sentinel lymph node biopsy for melanoma. We compare 2 imaging systems that are used for ICG-assisted sentinel lymph node biopsy.

Methods:

Fourteen patients underwent ICG-assisted sentinel lymph node biopsy for melanoma using the SPY Elite system (Novadaq, Mississigua, Canada) and the Hamamatsu PDE-Neo probe system (Mitaka USA, Park City, Utah). We analyzed costs for 2 systems that utilize ICG for sentinel lymph node biopsies.

Results:

Intraoperative use of ICG for sentinel lymph node biopsies was successful in correctly identifying sentinel lymph nodes. There was no difference between the Hamamatsu PDE-Neo probe and SPY Elite systems in the ability to detect sentinel lymph nodes; however, the former was associated with a lower operating cost and ease of use compared with the latter.

Conclusion:

ICG-assisted sentinel lymph biopsy using the SPY Elite or the Hamamatsu PDE-Neo probe systems for melanoma are comparable in terms of sentinel node detection. The Neo probe system delivers pertinent clinical data with the advantages of lower cost and ease of operation.

Limited effectiveness of patent blue dye in addition to isotope scanning for identification of sentinel lymph nodes: Cross-sectional real-life study in 1024 breast cancer patients

BACKGROUND

Although morbidity is reduced when sentinel lymph node (SLN) biopsy is performed with dual isotopic and blue dye identification, the effectiveness of adding blue dye to radioisotope remains debated because side effects including anaphylactic reactions.

PATIENTS AND METHODS

Using data from a prospectively maintained database, 1884 lymph node-negative breast cancer patients who underwent partial mastectomy with SLN mapping by a dual-tracer using patent blue dye (PBD) and radioisotope were retrospectively studied between January 2000 and July 2013. Patients with tumors <3 cm and with >1 node detected by one of the two techniques (N = 1024) were included in this real-life cross-sectional study.

RESULTS

Among the 1024 patients, 274 had positive SLN detected by isotopic and/or PBD staining. Only 4 patients having no detectable radioactivity in the axilla had SLN identified only by PBD staining (blue-only) while 26 patients had SLN only identified by isotopic detection (hot-only) illustrating failure rates of 9.5% (26/274) and 1.5% (4/274), respectively. Among these four patients, two had negative lymphoscintigraphy. Therefore, the contribution of PBD to metastatic nodes identification was relevant for only 2/274 patients (0.8%). Three patients (0.3%) had an allergic reaction with PBD, and anaphylactic shock occurred in two cases (0.2%).

CONCLUSIONS

The added-value of PBD to reduce the false-negative rate of SLN mapping is only limited to the rare cases in which no radioactivity is detectable in the axilla (<1%). When a radioisotope mapping agent is available, the use of PBD should be avoided, because it can induce anaphylaxis.