Optimal particle size of radiocolloid for sentinel node identification in breast cancer — Electron microscopic study and clinical comparison

Indocyanine green detects sentinel lymph nodes in early breast cancer

Objective

To explore the clinical value of indocyanine green (ICG) for the fluorescence-guided detection of sentinel lymph nodes (SLNs) during sentinel lymph node biopsy (SLNB) in patients with early breast cancer.

Methods

This retrospective study included female patients with breast cancer. Patients were administered methylene blue and ICG using standard techniques. All SLNs that were collected during surgery were submitted for pathological examination. SLNs were defined as those that were either fluorescent, blue, fluorescent and blue or palpably suspicious. Surgical complications, axillary recurrence, distant metastasis and overall survival rates were observed postoperatively.

Results

A total of 60 patients were enrolled in the study. The fluorescence detection rate of SLNs was 100% (n = 177), with a mean of 2.95 SLNs per patient. The methylene blue staining rate was 88.3% (n = 106), with a mean of 1.77 SLNs per patient. Pathological assessment of intraoperative frozen specimens revealed SLN metastases in 10 patients, who immediately underwent axillary lymph node dissection. No patient had axillary recurrence or distant metastases, with a survival rate of 100%. Patients who underwent SLNB showed good appearance in the axillary wound, with no limited shoulder joint abduction and upper limb oedema.

Conclusion

Fluorescence-guided SLNB has several advantages and is suitable for clinical application.

(99m)Tc-human serum albumin nanocolloids: particle sizing and radioactivity distribution

Several parameters affect the biodistribution of administered nanocolloids (NC) for Sentinel Lymph Node (SLN) detection: particle size distribution, number of Tc atoms per particle and specific activity (SA). Relatively few data are available with frequently conflicting results. (99m)Tc-NC-human serum albumin (HSA) Nanocoll®, Nanoalbumon® and Nanotop® were analysed for particles' dimensional and radioactivity distribution, and a mathematical model was elaborated to estimate the number of particles involved. Commercially available kits were reconstituted at maximal SA of 11 MBq/µg HSA. Particles size distribution was evaluated by Dynamic Light Scattering. These data were related to the radioactivity distribution analysis passing labelled NC through three polycarbonate filters (15-30-50-nm pore size) under vacuum. Highest radioactivity was carried by 30-50 nm particles. The smallest ones, even though most numerous, carried only the 10% of (99m)Tc atoms. Nanocoll and Nanotop are not significantly different, while Nanoalbumon is characterized by largest particles (>30 nm) that carried the most of radioactivity (80%). Smallest particles could saturate the clearing capacity of macrophages; therefore, if the tracer is used for SLN detection, more node tiers could be visualized, reducing accuracy of SLN mapping. Manufacturers could implement technical leaflets with particle size distribution and could improve the labelling protocol to provide clinicians useful information.

Sentinel lymph node detection in patients with vulvar carcinoma; Feasibility of intra-operative mapping with technetium-99m-labeled nanocolloid

AIMS

Sentinel lymph node (SLN) mapping appears to be feasible in patients with primary vulvar cancer. Previous protocols describe the injection of the technetium-99m-nanocolloid at least 3 h before surgery which involves two invasive procedures for the patient. In this study, we assessed the feasibility, safety, and accuracy of an intra-operative rather than preoperative SLN mapping in patients with primary vulvar cancer.

METHODS

Patients with histologically confirmed squamous cell vulvar cancer and clinically FIGO stage Ib disease underwent intra-operative SLN mapping by intradermal injection of the nanocolloid around the tumor. SLN were identified and removed before a complete inguinofemoral lymphnode dissection was performed. Surgical and pathologic data on all patients were prospectively entered into a database.

RESULTS

An SLN procedure was performed in 16 patients; 3 patients received unilateral lymphadenectomy, and 13 women underwent surgery on both groins. In all groins but 4 at least one SLN was clearly identified (detection rate 25/29, 86%). A median number of 2 SLN and 4 non-SLN per groin were removed. 3 of 16 patients (19%) had metastatic disease in the lymph nodes. There was no false negative SLN result.

CONCLUSION

Intra-operative SLN detection seems feasible in patients with early stage vulvar cancer. More patients need to be enrolled in this ongoing study before this more convenient technique can be considered safe.

Current trends and emerging future of indocyanine green usage in surgery and oncology: a literature review

Ever since Kitai first performed fluorescent navigation of sentinel lymph nodes (SLNs) using indocyanine green (ICG) dye with a charge-couple device and light emitting diodes, the intraoperative use of near infrared fluorescence has served a critical role in increasing our understanding in various fields of surgical oncology. Here the authors review the emerging role of the ICG fluorophore in the development of our comprehension of the lymphatic system and its use in SLN mapping and biopsy in various cancers. In addition, they introduce the novel role of ICG-guided video angiography as a new intraoperative method of assessing microvascular circulation. The authors attempt to discuss the promising potential in addition to assessing several challenges and limitations in the context of specific surgical procedures and ICG as a whole. PubMed and Medline literature databases were searched for ICG use in clinical surgical settings. Despite ICG's significant impact in various fields of surgical oncology, ICG is still in its nascent stages, and more in-depth studies need to be carried out to fully evaluate its potential and limitations.

Current technical overviews of sentinel lymph node biopsy for breast cancer

Sentinel lymph node biopsy (SLNB) is based on the hypothesis that the sentinel lymph node (SLN) reflects the lymph-node status and a negative SLN might allow complete axillary lymph node dissection (ALND) to be avoided. Although the survival outcome is still unknown, this technique has already become a standard of care for breast cancer patients. However, it is still important to discuss current techniques and some controversies. This article reviews these issues for a variety of SLNB techniques.

Added value of the presence of blue nodes or hot nodes in sentinel lymph node biopsy of breast cancer

BACKGROUND

Combined use of blue dye and radiocolloid is considered to be useful for sentinel lymph node (SLN) biopsy of breast cancer. Whether both techniques together is superior to either alone was analyzed.

PATIENTS AND METHODS

A consecutive series of 308 cases of breast cancer who underwent SLN biopsy using the combination technique was used. The frequency of a blue node or hot node was analyzed in all cases and only node-positive cases. Furthermore, the frequency of a blue node and hot node together, or either alone, and the highest radiocount of the SLNs in each case were examined for correlation with 8 clinicopathologic features. Three types of SLN containing both blue dye and radioactivity (blue-hot node), blue dye alone (blue-only node) and radioactivity alone (hot-only node), and the SLN radiocounts were analyzed for correlation with metastatic tumor.

RESULTS

Of 308 cases, a blue node was present in 298 (97%), a hot node in 295 (96%), and either a blue or hot node in 306 (99%). The presence of a blue node or hot node was similarly affected by previous surgical biopsy and body mass index (BMI), and the presence of a hot node was also affected by age and tumor location. However, the presence of either a blue node or hot node was not affected by any of these characteristics. Of 77 node-positive cases, 8 (10%), 15 (19%) and 6 (8%) were considered to be node-negative based on blue node, hot node and either blue node or hot node positivity, respectively. The frequency of positivity for SLN metastasis decreased in order from blue-hot, blue-only to hot-only nodes. Of 62 cases with metastatic hot nodes, six (10%) were negative when the hottest node was examined, but the second-hottest node was positive.

CONCLUSIONS

The added value of the presence of blue node or hot node was confirmed in the SLN biopsy using the combination technique, which suggests that all blue nodes and hot nodes need to be harvested.