Sentinel lymph node detection by combining nonradioactive techniques with contrast agents: State of the art and prospects

Should lymphadenectomy be recommended in radical surgery of intrahepatic cholangiocarcinoma patients? A retrospective study

PURPOSE

Intrahepatic cholangiocarcinoma (ICC) is an extremely deadly cancer with high recurrence incidence, particularly in patients with lymph node metastasis (LNM). The necessity of lymphadenectomy including lymph node biology (LNB) and dissection (LND) during ICC radical surgery remains debate.

METHODS

We retrospectively analyzed the patients diagnosed with ICC and underwent radical surgery at the Cancer Hospital of the Chinese Academy of Medical Sciences from 2012 to 2023.

RESULTS

A total of 308 ICC patients were involved in this study. pLNM+ group had poorer OS (P < 0.0001) and poorer DFS (P < 0.0001) compared with pLNM- group. Compared to the LN- group, LN+ group exhibited worse OS (P = 0.038) and worse DFS (P = 0.003). After PSM and IPTW, compared with LN- group, LNB exhibited longer operation time (IPTW: P = 0.0024) and longer hospitalization days (IPTW: P = 0.0112) with no significant differences in complications, DFS, and OS. Compared with LN- group, LND group had no better DFS and OS, only more complications (IPTW: P = 0.0191), longer operation time (all P < 0.001), higher risk of bleeding (all P < 0.05), transfusion (IPTW: P = 0.014) and longer hospitalization days (IPTW: P = 0.0044). Compared with LNB group, LND had longer operation time (P = 0.0227), higher risk of bleeding (P = 0.017) and transfusion (P = 0.0321), and more postoperative complications (P = 0.0425), with no difference in DFS and OS.

CONCLUSION

Lymphadenectomy does not necessarily provide long-term survival or recurrence benefits. LND only achieves the effect of LNB while negatively affects postoperative recovery without survival benefit for ICC patients. LNB can be performed for accurate pathological staging while not all patients may require LND based on their specific circumstances.

Advances in molecular imaging and targeted therapeutics for lymph node metastasis in cancer: a comprehensive review

Lymph node metastasis is a critical indicator of cancer progression, profoundly affecting diagnosis, staging, and treatment decisions. This review article delves into the recent advancements in molecular imaging techniques for lymph nodes, which are pivotal for the early detection and staging of cancer. It provides detailed insights into how these techniques are used to visualize and quantify metastatic cancer cells, resident immune cells, and other molecular markers within lymph nodes. Furthermore, the review highlights the development of innovative, lymph node-targeted therapeutic strategies, which represent a significant shift towards more precise and effective cancer treatments. By examining cutting-edge research and emerging technologies, this review offers a comprehensive overview of the current and potential impact of lymph node-centric approaches on cancer diagnosis, staging, and therapy. Through its exploration of these topics, the review aims to illuminate the increasingly sophisticated landscape of cancer management strategies focused on lymph node assessment and intervention.

Lymph node metastasis of intrahepatic cholangiocarcinoma: the present and prospect of detection and dissection

Intrahepatic cholangiocarcinoma (ICC) ranks as the second most primary liver cancer that often goes unnoticed with a high mortality rate. Hepatectomy is the main treatment for ICC, but only 15% of patients are suitable for surgery. Despite advancements in therapeutic approaches, ICC has an unfavorable prognosis, largely due to lymph node metastasis (LNM) that is closely linked to the elevated recurrence rates. Consequently, the identification of precise and suitable techniques for the detection and staging of LNM assumes paramount importance for ICC therapy. While preoperative imaging plays a crucial role in ICC diagnosis, its efficacy in accurately diagnosing LNM remains unsatisfactory. The inclusion of lymph node dissection as part of the hepatectomy procedures is significant for the accurate pathological diagnosis of LNM, although it continues to be a topic of debate. The concept of sentinel lymph node in ICC has presented a novel and potentially valuable approach for diagnosing LNM. This review aims to explore the current state and prospects of LNM in ICC, offering a promising avenue for enhancing the clinical diagnosis and treatment of ICC to improve patient prognosis.

Nano-tracers for sentinel lymph node detection: current trends in technique and application

Sentinel lymph node (SLN) detection and biopsy is a critical staging component for several cancers. Apart from established methods using dyes or radiolabeled colloids, newer techniques are emerging, like near-infrared fluorescent compounds, targeted molecular radiopharmaceuticals and magnetic nano-tracers. In the overview section of this review, we categorize SLN detection tracers based on their principle of use. We discuss the merits of existing tracers and provide a glimpse of in-development formulations. A subsequent clinical section explores the expanded role of SLN detection in management of various cancers, citing current medical guidelines and the leading conclusions of long-term clinical trials. The concluding section tries to provide a perspective of promising developments and the work required to bring them to clinical fruition.

Advances in photoacoustic imaging aided by nano contrast agents: special focus on role of lymphatic system imaging for cancer theranostics

Photoacoustic imaging (PAI) is a successful clinical imaging platform for management of cancer and other health conditions that has seen significant progress in the past decade. However, clinical translation of PAI based methods are still under scrutiny as the imaging quality and clinical information derived from PA images are not on par with other imaging methods. Hence, to improve PAI, exogenous contrast agents, in the form of nanomaterials, are being used to achieve better image with less side effects, lower accumulation, and improved target specificity. Nanomedicine has become inevitable in cancer management, as it contributes at every stage from diagnosis to therapy, surgery, and even in the postoperative care and surveillance for recurrence. Nanocontrast agents for PAI have been developed and are being explored for early and improved cancer diagnosis. The systemic stability and target specificity of the nanomaterials to render its theranostic property depends on various influencing factors such as the administration route and physico-chemical responsiveness. The recent focus in PAI is on targeting the lymphatic system and nodes for cancer diagnosis, as they play a vital role in cancer progression and metastasis. This review aims to discuss the clinical advancements of PAI using nanoparticles as exogenous contrast agents for cancer theranostics with emphasis on PAI of lymphatic system for diagnosis, cancer progression, metastasis, PAI guided tumor resection, and finally PAI guided drug delivery.

Functional roles of magnetic nanoparticles for the identification of metastatic lymph nodes in cancer patients

Staging lymph nodes (LN) is crucial in diagnosing and treating cancer metastasis. Biotechnologies for the specific localization of metastatic lymph nodes (MLNs) have attracted significant attention to efficiently define tumor metastases. Bioimaging modalities, particularly magnetic nanoparticles (MNPs) such as iron oxide nanoparticles, have emerged as promising tools in cancer bioimaging, with great potential for use in the preoperative and intraoperative tracking of MLNs. As radiation-free magnetic resonance imaging (MRI) probes, MNPs can serve as alternative MRI contrast agents, offering improved accuracy and biological safety for nodal staging in cancer patients. Although MNPs' application is still in its initial stages, exploring their underlying mechanisms can enhance the sensitivity and multifunctionality of lymph node mapping. This review focuses on the feasibility and current application status of MNPs for imaging metastatic nodules in preclinical and clinical development. Furthermore, exploring novel and promising MNP-based strategies with controllable characteristics could lead to a more precise treatment of metastatic cancer patients.

Looking deep inside tissue with photoacoustic molecular probes: a review

Significance

Deep tissue noninvasive high-resolution imaging with light is challenging due to the high degree of light absorption and scattering in biological tissue. Photoacoustic imaging (PAI) can overcome some of the challenges of pure optical or ultrasound imaging to provide high-resolution deep tissue imaging. However, label-free PAI signals from light absorbing chromophores within the tissue are nonspecific. The use of exogeneous contrast agents (probes) not only enhances the imaging contrast (and imaging depth) but also increases the specificity of PAI by binding only to targeted molecules and often providing signals distinct from the background.

Aim

We aim to review the current development and future progression of photoacoustic molecular probes/contrast agents.

Approach

First, PAI and the need for using contrast agents are briefly introduced. Then, the recent development of contrast agents in terms of materials used to construct them is discussed. Then, various probes are discussed based on targeting mechanisms, in vivo molecular imaging applications, multimodal uses, and use in theranostic applications.

Results

Material combinations are being used to develop highly specific contrast agents. In addition to passive accumulation, probes utilizing activation mechanisms show promise for greater controllability. Several probes also enable concurrent multimodal use with fluorescence, ultrasound, Raman, magnetic resonance imaging, and computed tomography. Finally, targeted probes are also shown to aid localized and molecularly specific photo-induced therapy.

Conclusions

The development of contrast agents provides a promising prospect for increased contrast, higher imaging depth, and molecularly specific information. Of note are agents that allow for controlled activation, explore other optical windows, and enable multimodal use to overcome some of the shortcomings of label-free PAI.