Endoscopic fluorescent lymphography for gastric cancer

Lymphography by radioisotope or dye is a well-known technique for visualizing the lymphatic drainage pattern in a neoplastic lesion and it is in use in gastric cancer.Indocyanine green(ICG)more recently has been validated in fluorescent lymphography studies and is under evaluation as a novel tracer agent in gastric cancer.The amount and dilution of ICG injected as well as the site and the time of the injection are not standardized.In our unit,endoscopic submucosal injections of ICG are made as 0.5 mg in 0.5 mL at four peritumoral sites the day before surgery(for a total of 2.0 mg in 2.0 mL).Detection instruments for ICG fluorescence are evolving.Near-infrared systems integrated into laparoscopic or robotic instruments(near-infrared fluorescence imaging)have shown the most promising results.ICG fluorescence recognizes the node that receives lymphatic flow directly from a primary tumor.This is defined as the sentinel lymph node,and it has a high predictive negative value at the cT1 stage,able to reduce the extent of gastrectomy and lymph node dissection.ICG also enhances the number of lymph nodes detected during extended lymphadenectomy for advanced gastric cancer.Nevertheless,the practical effects of ICG use in a single patient are not yet clear.Standardization of the technique and further studies are needed before fluorescent lymphography can be used extensively worldwide.Until then,current guidelines recommend an extensive lymphadenectomy as the standard approach for gastric cancer with suspected metastasis.

Study of the Dextran-DTPA-Gd at rabbit popliteal fossa lymph node metastasis from thigh transplanted tumor with interstitial magnetic resonance lymphography

Objective： The aim of the study was to investigate the developing situation of the interstitial magnetic resonance （MR） lymphoid contrast agent Dextran-DTPA-Gd through the rabbit popliteal fossa lymph node metastasis from thigh VX2 transplanted tumor injection to show targeting enhanced metastatic lymph nodes and lymphatics. Methods： VX2 tumor was transplanted to the right hind limb quadriceps of 12 healthy New Zealand rabbits and the left side as a contrast. Eight rabbits had homonymy popliteal lymph node metastasis after 1 month through 3.0 GE MRI and they were later injected with lym phatic targeting contrast agent Dextran-DTPA-Gd 0.4 mL （3.96 x 10^-3 tool/L） through bilateral hindlimb toe web respectively. Enhanced MR images were obtained with interval 10 min, 15 min, 20 rain, 25 min, 30 rain, 35 min, 40 rain, 45 rain, 50 min, 55 min, 60 min, 2 h, 4 h, and 24 h. The signal intensities before and after enhancing were measured to calculate the enhanc- ing rates （E%） of popliteal lymph node and the popliteal lymph node signal intensity-time curves were drawn to observe the development of cancer metastasis lymph nodes and lymphatics and to compare the differences of interval sides. Results： Ten minutes after injected into the rabbit＇s bilateral hindlimb toe web, we could see hind lymphatic and popliteal lymph nodes were strengthened significantly and evenly without blood vessels developing. The signal reached a peak after 35 rain with E% to 315%, which decreased to 205% after 4 h and would be undifferentiated with the surrounding tissues after 24 h. Sta- tistical analysis was made to popliteal lymph node enhancement rate. It was considered statistically significant as long as P 〈 0.05. The tumor-side popliteal lymph node manifested as coarse and irregular shape, lymphatic vessels tortuous dilated and lymphatic chain incomplete as a result of tumor infection. Conclusion： Dextran-DTPA-Gd is specific to lymphoid tissue development. It can targeting display regional lymphatic drainage concretion and the morphology of normal and cancer cells metastasis lymph nodes rapidly.

Review of Non-Contrast MR-Lymphography Techniques and Findings: Challenges and Opportunities

Lymphedema is a major disorder of lymphatic system that occurs primarily due to lymphatic system disorders or secondary lymphedema which is caused by radiation therapy involving lymph nodes or surgical operation dissection. Magnetic resonance lymphography (MRL) has been used to effectively examine the lymph vessels and identify their morphology. This review study intended to evaluate the role of non MR-lymphographic for the diagnosis assessment of lymphedema and to provide comprehensive review on clinical outcome of non-contrast MRI compared to MRI with contrast medium. In this study, scientific publications published in languages other than English were excluded. A systematic review was done in international databases including PubMed, Scopus, web of sciences, conference proceedings published till 2019. Non contrast MRI lymphography has strong capability to be the main imaging procedure of choice in the diagnosis lymphedema with accuracy up to 90%.

Application progress of lymphography in oncology

Lymphography is often used for the diagnosis of lymphatic metastasis in oncology.Determination of lymphatic metastasis is extremely important for accurate cancer staging,which may directly guide the clinical therapeutic scheme.In recent years,the technology of lymphography has developed rapidly on the basis of traditional lymphography,with the appearance of com-puted tomography(CT)lymphography,nuclear magnetic resonance(MR)lymphography,contrast-enhanced lym-phosonography,and so on;the diagnostic accuracy has also been improved.The imaging principles and methods of these various technologies of lymphography are reviewed in this paper,and their applications and significance in oncology are also discussed in detail.

Comparison of sentinel lymph node detection performances using blue dye in conjunction with indocyanine green or radioisotope in breast cancer patients: a prospective singlecenter randomized study

Objective:This randomized study aimed to compare the clinical efficacy between the novel dual tracer composed of indocyanine green(ICG)and blue dye(BD)and the conventional dual tracer composed of radioisotope and BD for sentinel lymph node(SLN)mapping in patients with breast cancer.Methods:This study enrolled 471 clinically lymph node-negative patients with primary breast cancer.All patients underwent mastectomy,and those undergoing sentinel lymph node biopsy(SLNB)were randomized to receive blue dye plus radioisotope(RB group)or BD plus ICG(IB group).The detection performances on SLN identification rate,positive SLN counts,detection sensitivity,and false-negative rate were compared between the two groups.Results:In the IB group,97%(194/200)of the patients who underwent the ICG and BD dual tracer injection showed fluorescentpositive lymphatic vessels within 2–5 min.The identification rate of SLNs was comparable between the IB group(99.0%,198/200)and the RB group(99.6%,270/271)(P=0.79).No significant differences were observed in the identification rate of metastatic SLNs(22.5%vs.22.9%,P>0.05,RB group vs.IB group,the same below),positive SLN counts(3.72±2.28 vs.3.91±2.13,P>0.05),positive metastatic SLN counts(0.38±0.84 vs.0.34±0.78,P>0.05),SLNB detection sensitivity(94.4%vs.92.5%,P>0.05),or false-negative rate(5.6%vs.7.5%,P>0.05)between the two groups.Conclusions:ICG can be used as a promising alternative tracer for radioisotope in SLN mapping,and when it is combined with BD in lymphangiography,it offers comparable detection sensitivity compared to the conventional lymphatic mapping strategies that are widely used in clinical practice.

Distal-to-proximal sequential ICG injection technique(DOPSIT)for lymphatic vessels mapping

Supermicrosurgical lymphaticovenular anastomosis(LVA)is the most sought-after procedure among lymphedema patients.However,the same enthusiasm is currently not shared among lymphedema surgeons due to the lackluster results of LVA.The common unfavorable experience with this famed procedure is at least partially caused by the difficulty in finding the lymph vessels.We share our time-tested indocyanine green-based lymph vessel mapping technique,which has helped us establish LVA as our procedure for all fluid-predominant lymphedema.

Lymphatic reconstruction with vascularized lymph vessel flap:lymph-interpositional-flap transfer

Lymph node transfer(LNT)and lymphatic anastomosis are popular reconstructive surgeries in managing lymphedema.However,lymphatic anastomosis requires the operator to be adept at super microsurgery,and LNT has significant donor-site lymphedema risks.To address these drawbacks,lymph-interpositional-flap transfer(LIFT),a novel lymphatic reconstruction method that does not require lymph node transfers or supermicrosurgical techniques,has been introduced.Lymph circulation after tissue replantation and free flap transfer was evaluated using indocyanine green(ICG)lymphography.Postoperative ICG lymphography showed linear to linear lymphatic reconnection between an amputee/flap and a recipient site in cases where the stumps of the lymph vessels were only approximated.This was a frequent phenomenon observed in replantation cases and some free tissue transfers.Based on these results,we developed a new lymphatic reconstruction using a flap designed to include the collecting lymph vessels for bridging a lymphatic gap.ICG is injected at the peripheries of donor sites or the distal boundaries of the lymphosome where the recipient site resides in.This allows us to visualize the axial lymphatic pathways.When LIFT is used to reconstruct a soft tissue defect,ICG is also injected at the proximal edge of it to visualize proximal lymph flows.The LIFT flap is designed to include lymphatic channels seen on pre-operative ICG lymphography.As these collecting lymph vessels reside deep in the superficial fascia,the flap is elevated with the deep fat intact.Intra-operative ICG lymphography is utilized to identify the proximal and distal lymphatic stumps on the flap,and absorbable sutures are used to tag these stumps for ease of recognition during the flap inset.LIFT is indicated for soft tissue defects in major lymphosomes,resulting in a significant lymphatic gap.The advantage of the LIFT technique is the ability to perform simultaneous soft tissue and lymphatic reconstruction.LIFT can also be applied in established lymphedema and elephantiasis.

间接淋巴造影

淋巴造影在显示正常大小淋巴结的内在结构方面比CT、MRI准确，对颈淋巴结早期转移诊断将有一定的价值，其中间接淋巴造影显影淋巴结有一定的优势。本文就间接淋巴造影原理、造影剂及其应用等方面进行综述。

Practical considerations in starting a peripheral lymphedema magnetic resonance imaging program

The management of chronic peripheral lymphedema benefits from a multidisciplinary approach in which magnetic resonance imaging(MRI)can play a key role.The imaging has been well described in the literature(including this journal),but the process for starting a novel imaging service line is complex.Participants in this process,including radiologists,imaging technical staff,information technologists,and revenue cycle managers,must be engaged and work in harmony to achieve success.The purpose of this article is to detail the building blocks and steps in starting a peripheral lymphedema MRI program,how our process evolved,and lessons learned along the way.