## 4 Discussion
Thus, it suggests that BLM also can reach lymph node tissue. Additional comprehensive studies, including analysis of the cellular localization of ICG and BLM, are necessary to support the findings. In theory, the problem of uneven tissue distribution of BLM and ICG could be solved by encapsulating both compounds inside a nanocarrier. Such an approach was explored in several studies, most of which used ICG as a photosensitizer. For example, [PERSON] et al. established a drug delivery system consisting of ICG and doxorubicin encapsulated in microvesicles to obtain effective synergistic photochemotherapy toward cervical cancer [33]. ICG was also used to solubilize the hydrophobic drug SN38 eliciting synergistic phototoxic and cytotoxic effects in vitro and in vivo against human glioblastoma cells and breast cancer cells upon NIR irradiation [34]. Importantly, ICG was combined with cisplatin (another standard drug used in ECT) within a hydrazided hyaluron/cisplatin/ICG coordination nano-prodrug, which appeared to be highly effective toward hepatocellular carcinoma [32]. However, it has to be noted that lipid carriers may not be delivered with the standard ESOPE protocol due to their instability in the electric field. On the other hand, lipid nanoparticles had been successfully delivered to colon cancer cells using electric pulses of millisecond duration [35]. Overall, the ECT protocol with the modification involving the fusion of ICG and chemotherapeutics entrapped in nanocarriers seems to be a promising approach to trigger synergistic cytotoxic and photovoltaic antitumor effects. One of the main applications of NIRF-ICG imaging is mapping the sentinel lymph nodes [3; 13; 36; 37]. In our study, we noticed fluorescence in the region of the popliteal node a few minutes after the injection. Histopathological examination confirmed that the fluorescent signal was from the regional lymph node. Our observation is in agreement with the clinical studies of [PERSON] et al. concluding that NIR lymph node mapping was a safe procedure that helped identify and resect normal-sized metastatic lymph nodes in a cat with MCT [38]. Combining ICG with bleomycin for ECT has a theranostic implication--allowing both treatment of the primary tumor with additional visualization of the sentinel node draining from the region of interest. Electrochemotherapy (ECT) is an effective local therapy for cutaneous tumors in human and veterinary patients. However, according to the National Institute for Occupational Safety and Health, handling cytotoxic drugs has been classified as an occupational health hazard [39; 40], thus all procedures that involve cytostatic drugs are a risk; such drugs are carcinogenic, mutagenic, teratogenic, and abortifacient, increasing the risk of stillbirth [39]. The administration of the cytotoxic drug may be controlled by using well-established guidelines for chemotherapy administration protocols, but the guidelines during intratumoral application are still complicated and sometimes challenging. Our experience in IT injections in the case of tumor masses that are dense in structure and have more fibrous tissue indicates the spillage usually occurs after a backward flush of the drug; on the other hand, in soft tumors, the spillage usually occurs through pores and holes in the necrotizing mass. In both cases, the contamination risk may be elevated whether the treatment is simultaneous ECT and surgical excision. We hypothesize that adding the ICG to the BLM may allow for fast visualization of the possible drug leakage and contaminants during the ECT. In this study, the tumor mass was small, and accidental drug outflow was noted. Thus, as we can state, the long-term benefits of NIRF imaging applications are not only for the patient during the procedure but also for the personnel's safety during ECT with IT injection. In our opinion, further investigations on NIRF imaging in ECT treatment might focus on its influence on the following:  
1.