Sentinel node mapping in lung cancer: the Holy Grail?

Sentinel Lymph Node Mapping in Lung Cancer: A Pilot Study for the Detection of Micrometastases in Stage I Non-Small Cell Lung Cancer

Lymphadenectomy represents a fundamental step in the staging and treatment of non-small cell lung cancer (NSCLC). To date, the extension of lymphadenectomy in early-stage NSCLC is a debated topic due to its possible complications. The detection of sentinel lymph nodes (SLNs) is a strategy that can improve the selection of patients in which a more extended lymphadenectomy is necessary. This pilot study aimed to refine lymph nodal staging in early-stage NSCLC patients who underwent robotic lung resection through the application of innovative intraoperative sentinel lymph node (SLN) identification and the pathological evaluation using one-step nucleic acid amplification (OSNA). Clinical N0 NSCLC patients planning to undergo robotic lung resection were selected. The day before surgery, all patients underwent radionuclide computed tomography (CT)-guided marking of the primary lung lesion and subsequently Single Photon Emission Computed Tomography (SPECT) to identify tracer migration and, consequently, the area with higher radioactivity. On the day of surgery, the lymph nodal radioactivity was detected intraoperatively using a gamma camera. SLN was defined as the lymph node with the highest numerical value of radioactivity. The OSNA amplification, detecting the mRNA of CK19, was used for the detection of nodal metastases in the lymph nodes, including SLN. From March to July 2021, a total of 8 patients (3 female; 5 male), with a mean age of 66 years (range 48-77), were enrolled in the study. No complications relating to the CT-guided marking or preoperative SPECT were found. An average of 5.3 lymph nodal stations were examined (range 2-8). N2 positivity was found in 3 out of 8 patients (37.5%). Consequently, pathological examination of lymph nodes with OSNA resulted in three upstages from the clinical IB stage to pathological IIIA stage. Moreover, in 1 patient (18%) with nodal upstaging, a positive node was intraoperatively identified as SLN. Comparing this protocol to the usual practice, no difference was found in terms of the operating time, conversion rate, and complication rate. Our preliminary experience suggests that sentinel lymph node detection, in association with the accurate pathological staging of cN0 patients achieved using OSNA, is safe and effective in the identification of metastasis, which is usually undetected by standard diagnostic methods.

Intraoperative combined color and fluorescent images-based sentinel node mapping in the porcine lung: comparison of indocyanine green with or without albumin premixing

OBJECTIVES

We developed a multimodal optical imaging system for intraoperative visualization of sentinel lymph nodes (SLNs). This study is to validate our system by showing SLNs in the lung through combined optical color and fluorescent image with indocyanine green (ICG) and ICG with human serum albumin (HSA).

METHODS

Identical ICG concentrations of ICG only or ICG:HSA was injected into the rat footpad and porcine lung. Absolute amounts of the fluorescents were scaled on the basis of animal weights. The entire procedures were recorded using color and near-infrared (NIR) charge-coupled device (CCD) cameras simultaneously, and the 2 images were merged by real-time image processing software. All fluorescence intensity signals to background ratio (SBR) and retention rates at SLN for both fluorescents were estimated and compared.

RESULTS

This newly developed intraoperative color and fluorescence optical imaging system successfully visualized the SLNs in animal experiments. The SLNs were identified 100% for both rat and pig under in vivo conditions. Real-time image processing software overcame the low signal of NIR fluorescence images. ICG and ICG:HSA provided no significantly different SBR in the SLN images for both rat thigh and pig lung.

CONCLUSIONS

The intraoperative optical imaging system enabled real-time image-guided surgery during SLN mapping in lung in an animal model. The ICG retention rate was similar to ICG:HSA. ICG alone can be useful for SLN imaging during lung cancer surgery.

Sentinel node navigation surgery by thoracoscopic fluorescence imaging system and molecular examination in non-small cell lung cancer

PURPOSE

The application of sentinel node navigation surgery in non-small cell lung cancer (NSCLC) is not popular because of the difficulty of sentinel node identification and the low incidence of complications after systemic lymph node dissection. We report the intraoperative assessment of sentinel node metastasis by thoracoscopic ICG fluorescence imaging system and real-time reverse transcription-polymerase chain reaction (RT-PCR).

METHODS

Sixty-one patients who underwent surgery between January 2009 and December 2010 were investigated for sentinel node biopsy. ICG fluorescence imaging was applied by an infrared light CCD system, and sentinel nodes were identified and dissected. Intraoperative real-time quantitative RT-PCR to determine the expression of cytokeratin 19 (CK-19) was performed for evaluation of metastasis and finally histologic examination of hematoxylin and eosin-stained, paraffin-embedded sections.

RESULTS

Sixteen (80%) of 20 patients with segmentectomy and 33 (80.5%) of 41 with lobectomy were identified for sentinel lymph nodes. The total identification rate was 80.3% (49 of 61). The false-negative rate was 2.1% (1 of 49). The overall accuracy rate was 78.7% (48 of 61 patients). Disease of four of these patients was upstaged to stage IIA by RT-PCR for CK-19 expression, which was positive for sentinel nodes and micrometastases.

CONCLUSIONS

These results demonstrated that thoracoscopic ICG fluorescence imaging-guided surgery and real-time quantitative RT-PCR were useful for sentinel node biopsy and might be a powerful tool for more focused pathologic or molecular evaluation for staging.

Engineering nanocomposite materials for cancer therapy

Cancer accounted for 13% of all deaths worldwide in 2005. Although early detection is critical for the successful treatment of many cancers, there are sensitivity limitations associated with current detection methodologies. Furthermore, many traditional anticancer drug treatments exhibit limited efficacy and cause high morbidity. The unique physical properties of nanoscale materials can be utilized to produce novel and effective sensors for cancer diagnosis, agents for tumor imaging, and therapeutics for cancer treatment. Functionalizing inorganic nanoparticles with biocompatible polymers and natural or rationally designed biomolecules offers a route towards engineering responsive and multifunctional composite systems. Although only a few such innovations have reached human clinical trial to date, nanocomposite materials based on functionalized metal and semiconductor nanoparticles promise to transform the way cancer is diagnosed and treated. This review summarizes the current state-of-the-art in the development of inorganic nanocomposites for cancer-related applications.

Nanotechnology in thoracic surgery

Nanotechnology is an exciting and rapidly progressing field offering potential solutions to multiple challenges in the diagnosis and treatment of lung cancer, with the potential for improving imaging and mapping techniques, drug delivery, and ablative therapy. With promising preclinical results in many applications directly applicable to thoracic oncology, it is possible that the frontiers of minimally invasive thoracic surgery will eventually be explored at the nanoscale.

Image-guided sentinel lymph node mapping and nanotechnology-based nodal treatment in lung cancer using invisible near-infrared fluorescent light

Current methods for sentinel lymph node (SLN) mapping and nodal treatment in lung cancer remain inadequate for routine clinical use. In this study, we discuss the potential for using the combination of invisible near-infrared (NIR) fluorescent light and nanotechnology for these applications. NIR fluorescence imaging has recently received significant attention for in vivo imaging applications because of its low tissue autofluorescence, high photon penetration into living tissue, and high signal-to-background ratio. Our large animal in vivo studies have been able to successfully identify SLNs in lung tissue, and several clinical studies have examined the use of NIR fluorescence imaging systems for SLN mapping in breast and gastric cancer. Promising new nanoparticle technologies, when combined with NIR fluorescence imaging, offer the potential for image-guided treatment of lymph nodes at high risk for tumor recurrence. This review provides a theoretic and empiric framework for developing the next generation of diagnostic and therapeutic agents for lung cancer.

Video-assisted thoracoscopic indocyanine green fluorescence imaging system shows sentinel lymph nodes in non-small-cell lung cancer

OBJECTIVE

The primary objective was to assess the feasibility and accuracy of intraoperative sentinel lymph node mapping by using a video-assisted thoracoscopic indocyanine green fluorescence imaging system in patients with clinical stage I non-small-cell lung cancer.

METHODS

Thirty-one patients who underwent operation between January 2009 and September 2009 were investigated for sentinel node biopsy. Indocyanine green fluorescence imaging was applied by an infrared light charge-coupled device, and sentinel nodes were identified intraoperatively and dissected. Histologic examination by hematoxylin-eosin staining was used to evaluate metastases.

RESULTS

Sentinel lymph nodes were identified by segmentectomy in 11 of 14 patients (78.5%) and by lobectomy in 14 of 17 patients (82.4%). The total identification rate was 80.7% (25/31 patients), the false-negative rate was 0% (0/24 patients), and the overall accuracy rate was 80.7% (25/31 patients).

CONCLUSION

Video-assisted thoracoscopic indocyanine green fluorescence image-guided surgery is feasible for sentinel node biopsy and may be a powerful tool to eliminate unnecessary lymph node dissection in patients with lung cancer.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.