Evaluation of lymphedema in upper extremities by MR lymphangiography: Comparison with lymphoscintigraphy

Analysis on efficacy of magnetic resonance lymphangiography using INV-001 in healthy beagle dogs

We aimed to conduct a proof-of-concept study of INV-001 in visualizing lymphatic vessels and nodes without venous contamination and to determine the optimal dose condition of INV-001 for magnetic resonance lymphangiography (MRL) in healthy beagles. MRL was performed using a 3.0-Tesla (T) whole body clinical magnetic resonance imaging (MRI) scanner. A dose-finding study of INV-001 for MRL in beagles (N = 6) was carried out according to an adaptive optimal dose finding design. For the reproducibility study (N = 6), MRL was conducted at selected INV-001 doses (0.056 and 0.112 mg Fe/kg) with a 15 mM concentration. Additionally, an excretion study (N = 3) of INV-001 was conducted by analyzing T1, T2, and T2* maps of the liver and kidney 48 h post-administration. INV-001 administration at doses of 0.056 and 0.112 mg Fe/kg (concentration: 15 mM) consistently demonstrated the visualization of contrast-enhanced lymphatic vessels and nodes without venous contamination in the beagles. The contrast enhancement effect was highest at 30 min after INV-001 administration, then gradually decreasing. No toxicity-related issues were identified during the study. After 48 h, the T1, T2, and T2* values in the liver and both kidneys were found to be comparable to the pre-administration values, indicating thorough INV-001 excretion. The optimal dosing conditions of INV-001 for MRL for contrast-enhanced visualization of lymphatic vessels and nodes exclusively with no venous contamination in beagles was determined to be 0.056 mg Fe/kg with a 15 mM concentration.

Association between Bioimpedance Spectroscopy and Magnetic Resonance Lymphangiography in the Diagnosis and Assessment of Lymphedema

BACKGROUND

 This study assesses associations between bioimpedance spectroscopy (BIS) and magnetic resonance lymphangiography (MRL) in the staging and assessment of lymphedema.

METHODS

 Adults who received MRL and BIS between 2020 and 2022 were included. We collected fluid, fat, and lymphedema severity ratings, and measured fluid stripe thickness, subcutaneous fat width, and lymphatic diameter on MRL. BIS lymphedema index (L-Dex) scores were collected from patient charts. We assessed sensitivity and specificity of L-Dex scores to detect MRL-identified lymphedema, and examined associations between L-Dex scores and MRL imaging measures.

RESULTS

 Forty-eight limbs across 40 patients were included. L-Dex scores had 72.5% sensitivity and 87.5% specificity for detecting MRL-defined lymphedema, with a 96.7% estimated positive predictive value and 38.9% negative predictive value. L-Dex scores were associated with MRL fluid and fat content scores (p ≤ 0.05), and lymphedema severity (p = 0.01), with better discrimination between fluid than fat content levels on pairwise analysis, and poor discrimination between adjacent severity levels. L-Dex scores were correlated with distal and proximal limb fluid stripe thickness (distal: rho = 0.57, p < 0.01; proximal: rho = 0.58, p < 0.01), partially correlated with distal subcutaneous fat thickness when accounting for body mass index (rho = 0.34, p = 0.02), and were not correlated with lymphatic diameter (p = 0.25).

CONCLUSION

 L-Dex scores have high sensitivity, specificity, and positive predictive value for the identification of MRL-detected lymphedema. L-Dex has difficulty distinguishing between adjacent severity levels of lymphedema and a high false negative rate, explained in part by reduced discrimination between levels of fat accumulation.

MR Lymphangiography in Lymphatic Disorders: Clinical Applications, Institutional Experience, and Practice Development

Lymphatic flow and anatomy can be challenging to study, owing to variable lymphatic anatomy in patients with diverse primary or secondary lymphatic pathologic conditions and the fact that lymphatic imaging is rarely performed in healthy individuals. The primary components of the lymphatic system outside the head and neck are the peripheral, retroperitoneal, mesenteric, hepatic, and pulmonary lymphatic systems and the thoracic duct. Multiple techniques have been developed for imaging components of the lymphatic system over the past century, with trade-offs in spatial, temporal, and contrast resolution; invasiveness; exposure to ionizing radiation; and the ability to obtain information on dynamic lymphatic flow. More recently, dynamic contrast-enhanced (DCE) MR lymphangiography (MRL) has emerged as a valuable tool for imaging both lymphatic flow and anatomy in a variety of congenital and acquired primary or secondary lymphatic disorders. The authors provide a brief overview of lymphatic physiology, anatomy, and imaging techniques. Next, an overview of DCE MRL and the development of an MRL practice and workflow in a hybrid interventional MRI suite incorporating cart-based in-room US is provided, with an emphasis on multidisciplinary collaboration. The spectrum of congenital and acquired lymphatic disorders encountered early in an MRL practice is provided, with emphasis on the diversity of imaging findings and how DCE MRL can aid in diagnosis and treatment of these patients. Methods such as DCE MRL for assessing the hepatic and mesenteric lymphatic systems and emerging technologies that may further expand DCE MRL use such as three-dimensional printing are introduced. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Current and Developing Lymphatic Imaging Approaches for Elucidation of Functional Mechanisms and Disease Progression

Study of the lymphatic system, compared to that of the other body systems, has been historically neglected. While scientists and clinicians have, in recent decades, gained a better appreciation of the functionality of the lymphatics as well as their role in associated diseases (and consequently investigated these topics further in their experimental work), there is still much left to be understood of the lymphatic system. In this review article, we discuss the role lymphatic imaging techniques have played in this recent series of advancements and how new imaging techniques can help bolster this wave of discovery. We specifically highlight the use of lymphatic imaging techniques in understanding the fundamental anatomy and physiology of the lymphatic system; investigating the development of lymphatic vasculature (using techniques such as intravital microscopy); diagnosing, staging, and treating lymphedema and cancer; and its role in other disease states.

Lymphoscintigraphy findings in patients with chylothorax: influence of biochemical parameters

BACKGROUND

Chylothorax is a condition that can be challenging to diagnose due to its nonspecific clinical presentation. Several biochemical parameters of chylous pleural effusion have been identified as important indicators for the diagnosis of chylothorax. Lymphoscintigraphy is utilized to assess chylothorax and determine the location of chyle leakage. The present study aimed to evaluate the correlation between the biochemical parameters of chylous pleural effusion and 99mTc-dextran (99mTc-DX) lymphoscintigraphy in diagnosing chylothorax.

MATERIAL AND METHODS

A total of 120 patients were enrolled in the study, 83 of the patients with unilateral chylothorax, and 37 with bilateral chylothorax. All patients underwent both 99mTc-DX lymphoscintigraphy and pleural effusion laboratory analysis. The 99mTc-DX lymphoscintigraphy images were categorized as positive or negative groups based on the presence or absence of abnormal radioactive tracer accumulation in the thorax, respectively. The biochemical parameters of the two groups were subsequently compared.

RESULTS

Among these patients, 101 (84.17%) had exudative effusions, while 19 (15.83%) had transudative effusions, as determined by the levels of pleural effusion protein, lactate dehydrogenase and cholesterol. Abnormal tracer accumulation in thorax was observed in 82 patients (68.33%). Our findings indicated that lymphoscintigraphy results were not associated with exudative and transudative chylothorax (P = 0.597). The lymphoscintigraphy positive group displayed significantly higher levels of pleural effusion triglyceride and pleural effusion triglyceride/serum triglyceride ratio in all biochemical parameters, compared to the negative group (P = 0.000 and P = 0.005). We identified cutoff values of 2.870 mmol/L for pleural effusion triglycerides and 4.625 for pleural effusion triglyceride/serum triglyceride ratio, respectively, which can facilitate differentiating the positive and negative cases on lymphoscintigraphy.

CONCLUSION

Lymphoscintigraphy technique is a dependable diagnostic tool for the qualitative assessment of chylous pleural effusion. Higher pleural effusion triglyceride level and pleural effusion triglyceride/serum triglyceride ratio indicate a positive result in patients with chylothorax on lymphoscintigraphy, with the cutoff values of 2.870 mmol/L and 4.625 aiding in the diagnosis.

Pneumatic Compression-Assisted Lymphoscintigraphy for Quantitative Evaluation of Breast Cancer-Related Lymphedema

OBJECTIVES

Acquired lymphedema of upper extremity is a chronic pathologic status that frequently occurs after breast cancer treatment. Reliable and quantitative evaluation of lymphedema is crucial for successful management of patients. Although lymphoscintigraphy is the primary investigation for the confirmation and evaluation of lymphedema, the specific protocol of stress intervention is not well established. This study aims to introduce intermittent pneumatic compression (IPC) as a part of stress lymphoscintigraphy and compare the effectiveness of conventional stress lymphoscintigraphy (CSL) and pneumatic compression-assisted lymphoscintigraphy (PCAL).

METHODS

Our study was designed as a retrospective analysis of 85 breast cancer patients with lymphedema who underwent lymphoscintigraphy utilizing either IPC device or conventional stress maneuver and received complex decongestive therapy. The flow extent of the lymphatic fluid (FE) was evaluated using a 0- to 4-point scale based on lymphoscintigraphic images. The visualization of lymph nodes was also assessed. The clinical outcomes were evaluated by changes in side-to-side circumferential and volume differences of upper extremities and compared between groups.

RESULTS

Of 85 patients, 47 underwent CSL, and 38 underwent PCAL. Participants with relatively preserved flow extent of the lymphatic fluid (FE 3) showed a significant difference in percentage reduction of volume (PRV) between CSL and PCAL groups (P = 0.036). In the other groups, CSL and PCAL demonstrated comparable differences in PRV without statistical significance.

CONCLUSION

Our study suggests that participants in the PCAL group with relatively preserved lymphatic flow extent (FE 3) had better PRV compared with those in the CSL group. The use of IPC devices in lymphoscintigraphy with the novel stress maneuver can help in the quantitative description of lymphedema status and the selection of an appropriate treatment method.

The Clinical Usefulness of Ultrasonographic Measurement Technique in Patients with Lower Extremity Lymphedema

Background: A previous study reported a new ultrasonography (US) measurement technique to evaluate the cross-sectional area (ΔCSA) of lymphedema in the upper extremity. This ΔCSA correlated well with parameters, such as the circumference, volumetry, and bioimpedance analysis (BIA) in healthy people and upper extremity lymphedema patients. This study examined whether a US measurement technique is clinically useful in patients with lymphedema in the lower extremity. Methods and Results: Forty patients diagnosed with unilateral lower extremity lymphedema were enrolled in this study. The subjects' leg circumference, BIA, isokinetic strength, and ΔCSA were examined on the same day. The leg circumference was measured at 15 cm above the knee (AK) and below the knee (BK) crease using a tape measure. BIA was performed by a trained physical therapist, and the data of impedance (Z) at 1 and 5 kHz of each side of the lower limbs and extracellular water (ECW) were used. A fully experienced physician measured soft tissue thickness, the distance between the skin and the fascia of the muscle, three times each at the anterior, medial, posterior, and lateral aspects of the bilateral legs by US at 15 cm AK and BK. The amount of soft tissue in the ΔCSA was calculated using the designed formula from the mean values of the thicknesses. Each parameter was calculated as the ratio of the sound side to the lesion side. The Pearson and Spearman correlation coefficients were used to assess the significance of these parameters. The ratio of ΔCSA measured at 15 cm AK and BK showed strong positive correlations with the circumference difference at the same level (rho = 0.790, p = 0.000, and rho = 0.882, p = 0.000, respectively). In addition, it showed moderate or strong correlations with the ratio of Z at 5 and 1 kHz in the BIA of the lower limbs (AK15, r = -0.511, p = 0.001 and r = -0.497, p = 0.001; BK15, r = -0.780, p = 0.000 and r = -0.756, p = 0.000, respectively). Although ECW and body mass index showed weak positive correlations with the ratio of ΔCSA measured at 15 cm BK, there was no significant correlation between the ratio of ΔCSA and the isokinetic muscle strength. Conclusion: The ΔCSA results showed moderate-to-strong correlations with other conveniently used methods except for the isokinetic muscle strength. As the US ΔCSA technique could measure lymphedema status with a structural consideration, it could also be recommended as a conventional measurement method in patients with upper and lower extremity lymphedema.

Imaging of the Lymphatic Vessels for Surgical Planning: A Systematic Review

BACKGROUND

Secondary lymphedema is a common complication after surgical or radiotherapeutic cancer treatment. (Micro) surgical intervention such as lymphovenous bypass and vascularized lymph node transfer is a possible solution in patients who are refractory to conventional treatment. Adequate imaging is needed to identify functional lymphatic vessels and nearby veins for surgical planning.

METHODS

A systematic literature search of the Embase, MEDLINE ALL via Ovid, Web of Science Core Collection and Cochrane CENTRAL Register of Trials databases was conducted in February 2022. Studies reporting on lymphatic vessel detection in healthy subjects or secondary lymphedema of the limbs or head and neck were analyzed.

RESULTS

Overall, 129 lymphatic vessel imaging studies were included, and six imaging modalities were identified. The aim of the studies was diagnosis, severity staging, and/or surgical planning.

CONCLUSION

Due to its utility in surgical planning, near-infrared fluorescence lymphangiography (NIRF-L) has gained prominence in recent years relative to lymphoscintigraphy, the current gold standard for diagnosis and severity staging. Magnetic resonance lymphography (MRL) gives three-dimensional detailed information on the location of both lymphatic vessels and veins and the extent of fat hypertrophy; however, MRL is less practical for routine presurgical implementation due to its limited availability and high cost. High frequency ultrasound imaging can provide high resolution imaging of lymphatic vessels but is highly operator-dependent and accurate identification of lymphatic vessels is difficult. Finally, photoacoustic imaging (PAI) is a novel technique for visualization of functional lymphatic vessels and veins. More evidence is needed to evaluate the utility of PAI in surgical planning.

A Prospective Study on the Safety and Efficacy of Vascularized Lymph Node Transplant

PURPOSE

While vascularized lymph node transplant (VLNT) has gained popularity, there are a lack of prospective long-term studies and standardized outcomes. The purpose of this study was to evaluate the safety and efficacy of VLNT using all available outcome measures.

METHODS

This was a prospective study on all consecutive patients who underwent VLNT. Outcomes were assessed with 2 patient-reported outcome metrics, limb volume, bioimpedance, need for compression, and incidence of cellulitis.

RESULTS

There were 89 patients with the following donor sites: omentum (73%), axilla (13%), supraclavicular (7%), groin (3.5%). The mean follow-up was 23.7±12 months. There was a significant improvement at 2 years postoperatively across all outcome measures: 28.4% improvement in the Lymphedema Life Impact Scale, 20% average reduction in limb volume, 27.5% improvement in bioimpedance score, 93% reduction in cellulitis, and 34% of patients no longer required compression. Complications were transient and low without any donor site lymphedema.

CONCLUSIONS

VLNT is a safe and effective treatment for lymphedema with significant benefits fully manifesting at 2 years postoperatively. Omentum does not have any donor site lymphedema risk making it an attractive first choice.

Contrast-enhanced ultrasound: a new tool for imaging the superficial lymphatic vessels of the upper limb

Background

Despite the new lymphatic imaging methods, there is still a need for a straightforward method of detecting lymphatic abnormalities. Our goal was to investigate the feasibility of applying a contrast enhanced ultrasound (CEUS) procedure as a new approach for visualising the superficial lymphatic vessels of the upper limb.

Methods

Thirty healthy volunteers were examined with CEUS after bilateral intradermal injection of Sonazoid® contrast agent in distal antebrachium. We registered factors affecting intradermal injections, imaging of the superficial lymphatic vessels and the enhancement time of contrast agent reaching the levels of elbow and axilla.

Results

CEUS imaging of superficial lymphatic vessels was successful in 59 of 60 upper limbs (98.3%). Median [interquartile ranges] enhancement times of contrast agent to reach the elbow (right 18 s [11–25], left 15 s [12–25]) and axilla (right 77 s [33–118], left 66 s [42–115]) were equally fast. Successful intradermal injections were found to result in two types of contrast enhancement (strong or moderate), while the enhancement time depended on the type of the successful injection. No major differences in enhancement times were observed related to sex, body mass index, age, or side of the arm.

Conclusions

The superficial lymphatic pathways of the upper limb can be visualised with CEUS imaging. Since enhancement time is dependent on the success of intradermal injections, one must pay attention to the injection technique. Further studies are needed to evaluate the method in patients with lymphatic function disorders such as breast cancer therapy related lymphoedema.

Imaging biomarkers for diagnosis and treatment response in patients with lymphedema

Lymphedema is defined as a dysfunction of the lymphatic system producing an accumulation of lymphatic fluid in the surrounding tissue, as well as edema and fibrosis. A total of 250 million people worldwide are affected by this condition. Greater than 99% of these cases are related to a secondary cause. As there is a lack of curative therapy, the goal involves early diagnosis, in order to prevent the progression of the disease. Additionally, early diagnosis can aid in decreasing the demand for more complex surgical procedures. Currently, there is an impressive breadth of diagnostic tests available for these patients. We aimed to review the available literature in relation to the utilization of imaging biomarkers for the early diagnosis and treatment response in lymphedema.

Relationship Between the Circumference Difference and Findings of Indocyanine Green Lymphography in Breast Cancer-Related Lymphedema

BACKGROUND

Breast cancer-related lymphedema (BCRL) is a common complication. Indocyanine green (ICG) lymphography has been performed to assess lymphatic functionality. We found that some BCRL patients had a difference in circumference in partial regions only. The purpose of this study was to evaluate the patients with BCRL about the correlation between the difference in circumference and the findings of ICG lymphography.

METHODS

One hundred fifty-five patients with unilateral BCRL were enrolled in this study. We evaluated the differences in circumference taken at 4 parts on the upper limb (at around the wrist, forearm, elbow, and brachium). The difference in circumference was evaluated between the affected part (Caf) and the unaffected part (Cun). We calculated the circumference difference rate (CDR) as follows: CDR = 100 (Caf - Cun)/Caf. First, we classified each part of all BCRL patients (620 parts) based on the findings of ICG lymphography (linear, collateral, dermal back flow [DBF], and no enhancement) and evaluated the correlation. Second, in the patients with partial volume change, we compared the mean CDR in each part.

RESULTS

One hundred six parts were of a linear pattern, 31 parts were collateral, 350 parts were DBF, and 133 parts had no enhancement. The mean CDR of each finding was 3.3% in linear, 4.0% in collateral, 9.6% in DBF, and 9.4% in no enhancement. There was no significant difference between linear and collateral (P = 0.62), DBF, and no enhancement (P = 0.89) patterns. However, there was a significant difference between linear or collateral and DBF or no enhancement (all P < 0.001). In the 22 patients with distal DBF and proximal linear, the CDR was significantly higher in the forearm compared with the brachium (6.4% and 3.0%; P = 0.003). In the 26 patients with distal linear and proximal DBF, the CDR was significantly higher in the brachium compared with the forearm (4.3% and 7.7%; P = 0.005).

CONCLUSIONS

There was a significant correlation between the difference in circumference and the severity of ICG findings.

Magnetic resonance lymphangiography: with or without contrast?

Lymphedema is an important medical issue around the world, caused by an anomalous collection of fluid in soft tissue due to congenital malformations or stenosis or obstruction of lymphatic vessels. Magnetic resonance lymphangiography (MRL) is an emerging technique focused on noninvasive or minimally invasive imaging of lymphatics with the goal to diagnose and treat lymphedema. This review will briefly discuss lymphatic imaging starting with lymphography and radionuclide lymphoscintigraphy up to the newest methods, focusing on MRL, a rising technique, and highlighting the technical aspects fundamental for achieving high-resolution MRL.

Lymphatic Development and Implications for Diagnosis and Therapy

The lymphatic system was first described in the 17th century independently by Olaus Rudbeck and Thomas Bartholin. Since then, there has been deep-seated fascination with its development, function, and dysfunction.

Visualization of Both the Superficial and Deep Lymphatic System of the Upper Extremity Using Magnetic Resonance Lymphography

Background: The lymphatic system consists of the superficial and deep lymphatic system. Several diagnostic methods are used to assess the lymphatic system. Lymphoscintigraphy and indocyanine green lymphography are widely applied, both showing disadvantages, such as a poor resolution and lack of field of view. Magnetic resonance lymphography (MRL) shows satisfactory temporal and spatial resolution. The aim of this study was to assess both the superficial and deep lymphatic system in the upper extremity of healthy subjects, using an MRL protocol. Methods and Results: Ten healthy volunteers underwent an MRL examination, using a three Tesla MRI unit. Water-soluble gadolinium was used as a contrast agent. MRL images were evaluated by an experienced radiologist on image quality, enhancement of veins and lymphatic vessels, and characteristics of the latter. Overall image quality was good to excellent. In all subjects, veins and lymphatic vessels could be distinguished. Superficial and deep lymphatic vessels were seen in 9 out of 10 subjects. Lymphatic vessels with a diameter between 0.9 and 4.3 mm were measured. Both veins and lymphatic vessels showed their characteristic appearance. Enhancement of veins was seen directly after contrast agent injection, which decreased over time. Lymphatic vessel enhancement slowly increased over time. Mean total MRL examination (room) time was 110 minutes (81 minutes scan time). Conclusions: The MRL protocol accurately visualizes both deep and superficial lymphatic vessels showing their characteristic appearances with high spatial resolution, indicating the MRL can be of value in diagnosing and staging peripheral lymphedema.

Lymphoscintigraphic Findings as Indicators of Lymphaticovenous Anastomosis Outcome in Patients With Extremity Lymphedema: A Retrospective Cohort Study

PURPOSE

This study was performed to evaluate the usefulness of lymphoscintigraphy in predicting the surgical outcomes of lymphaticovenous anastomosis (LVA) in a patient with extremity lymphedema.

PATIENTS AND METHODS

We retrospectively evaluated 133 patients with extremity lymphedema who underwent lymphoscintigraphy followed by LVA surgery from February 2018 to March 2020. Lymphoscintigraphic findings were evaluated on the following parameters: the extent of dermal backflow (small/large), lymphatic flow patterns (trunk flow pattern/proximal-restricted pattern/distal-restricted pattern), visualization of lymph nodes, and collateral lymphatic vessels. The mean circumferential difference change before and after surgery, circumferential reduction (CR) rate (%), was used as the clinical outcome variables.

RESULTS

A decrease in circumference was observed in 93 (69.9%) of 133 patients after LVA. The extent of dermal backflow and lymphatic flow patterns was significantly correlated with improved clinical outcomes after LVA. The large extent of the dermal backflow group showed a more significant CR rate than the small extent (19.27% vs 1.24%, P = 0.005). The TP group showed the most significantly decreased CR rate to 21.46%, and the proximal-restricted pattern and distal-restricted pattern groups were -2.49% and -5.33%, respectively (P < 0.001). Multivariate analysis revealed that dermal backflow and lymphatic flow patterns were independent predictors of therapeutic outcome (P < 0.001).

CONCLUSIONS

Our study demonstrates that pretreatment lymphoscintigraphy may help predict the therapeutic effect of LVA in patients with extremity lymphedema. Furthermore, dermal backflow and lymphatic flow patterns are independent predictors of CR rate after LVA surgery for extremity lymphedema.

Systematic Review of Magnetic Resonance Lymphangiography From a Technical Perspective

BACKGROUND

Clinical examination and lymphoscintigraphy are the current standard for investigating lymphatic function. Magnetic resonance imaging (MRI) facilitates three-dimensional (3D), nonionizing imaging of the lymphatic vasculature, including functional assessments of lymphatic flow, and may improve diagnosis and treatment planning in disease states such as lymphedema.

PURPOSE

To summarize the role of MRI as a noninvasive technique to assess lymphatic drainage and highlight areas in need of further study.

STUDY TYPE

Systematic review.

POPULATION

In October 2019, a systematic literature search (PubMed) was performed to identify articles on magnetic resonance lymphangiography (MRL).

FIELD STRENGTH/SEQUENCE

No field strength or sequence restrictions.

ASSESSMENT

Article quality assessment was conducted using a bespoke protocol, designed with heavy reliance on the National Institutes of Health quality assessment tool for case series studies and Downs and Blacks quality checklist for health care intervention studies.

STATISTICAL TESTS

The results of the original research articles are summarized.

RESULTS

From 612 identified articles, 43 articles were included and their protocols and results summarized. Field strength was 1.5 or 3.0 T in all studies, with 25/43 (58%) employing 3.0 T imaging. Most commonly, imaging of the peripheries, upper and lower limbs including the pelvis (32/43, 74%), and the trunk (10/43, 23%) is performed, including two studies covering both regions. Imaging protocols were heterogenous; however, T2 -weighted and contrast-enhanced T1 -weighted images are routinely acquired and demonstrate the lymphatic vasculature. Edema, vessel, quantity and morphology, and contrast uptake characteristics are commonly reported indicators of lymphatic dysfunction.

DATA CONCLUSION

MRL is uniquely placed to yield large field of view, qualitative and quantitative, 3D imaging of the lymphatic vasculature. Despite study heterogeneity, consensus is emerging regarding MRL protocol design. MRL has the potential to dramatically improve understanding of the lymphatics and detect disease, but further optimization, and research into the influence of study protocol differences, is required before this is fully realized.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

State-of-the-Art Lymphedema Surgery Treatment Program

The purpose of this article is to describe the multidisciplinary lymphedema surgery treatment program at Washington University in St. Louis. In this article, we discuss our collaboration with colleagues in medicine and therapy for conservative management and lymphedema staging. We describe our preferred imaging modalities for diagnosis, staging, and surgical treatment. Finally, we provide an overview of the surgical procedures we perform and our surgical treatment algorithm.

Standardization of lower extremity quantitative lymphedema measurements and associated patient-reported outcomes in gynecologic cancers

Practice changing standardization of lower extremity lymphedema quantitative measurements with integrated patient reported outcomes will likely refine and redefine the optimal risk-reduction strategies to diminish the devastating limb-related dysfunction and morbidity associated with treatment of gynecologic cancers. The National Cancer Institute (NCI), Division of Cancer Prevention brought together a diverse group of cancer treatment, therapy and patient reported outcomes experts to discuss the current state-of-the-science in lymphedema evaluation with the potential goal of incorporating new strategies for optimal evaluation of lymphedema in future developing gynecologic clinical trials.

A systematic review of magnetic resonance lymphography for the evaluation of peripheral lymphedema

OBJECTIVE

Visualization of the lymphatic system is necessary for both early diagnosis and associated treatments. A promising imaging modality is magnetic resonance lymphography (MRL). The aim of this review was to summarize different MRL protocols, to assess the clinical value in patients with peripheral lymphedema, and to define minimal requirements necessary for visualization of lymphatics.

METHODS

A systematic literature search was conducted in PubMed, Embase, and the Cochrane Library in December 2018. Studies performing MRL in patients with peripheral lymphedema or healthy participants were included. Study design, population, etiology, duration of lymphedema, clinical staging, contrast agent, dose, injection site, and technical magnetic resonance imaging details were analyzed. No meta-analyses were performed because of different study aims and heterogeneity of the study populations.

RESULTS

Twenty-five studies involving 1609 patients with both primary lymphedema (n = 669) and secondary lymphedema (n = 657) were included. Upper and lower limbs were examined in 296 and 602 patients, respectively. Twenty-two studies used a gadolinium-based contrast agent that was injected intracutaneously or subcutaneously in the interdigital web spaces. Contrast-enhanced T1-weighted combined with T2-weighted protocols were most frequently used. T1-weighted images showed lymphatics in 63.3% to 100%, even in vessels with a diameter of ≥0.5 mm. Dermal backflow and a honeycomb pattern were clearly recognized.

CONCLUSIONS

MRL identifies superficial lymphatic vessels with a diameter of ≥0.5 mm with high sensitivity and specificity and accurately shows abnormal lymphatics and lymphatic drainage patterns. Therefore, MRL could be of clinical value in both early and advanced stages of peripheral lymphedema. Minimum requirements of an MRL protocol should consist of a gadolinium-based contrast-enhanced T1-weighted gradient-recalled echo sequence combined with T2-weighted magnetic resonance imaging, with acquisition at least 30 minutes after injection of contrast material.

Surgical treatment of lymphedema

Lymphedema is a debilitating and progressive condition, which results in the accumulation of lymphatic fluid within the interstitial compartments of tissues and hypertrophy of adipose tissue due to the impairment of lymphatic circulation. The mainstay of current lymphedema treatment is nonsurgical management such as complex decongestive therapy and compression therapy. Recently, surgical treatment of lymphedema based on microsurgery has been developed to enable the functional recovery of lymphatic drainage and has complemented nonsurgical treatment. Lymphaticovenular anastomosis and vascularized lymph node transfer are representative physiologic surgeries in the treatment of lymphedema. Lymphaticovenular anastomosis is conducted to drain lymphatic fluid from obstructed lymphatic vessels to the venous circulation through surgically created lymphaticovenous shunts. Vascularized lymph node transfer involves harvesting lymph nodes with their vascular supply and transferring this vascularized tissue to the lymphedema lesion as a free flap. In addition to physiologic surgeries, ablative surgeries such as direct excision and liposuction also can be performed, especially for end-stage cases. Indications for surgical treatment vary across institutions. It is important not to delay physiologic surgery in mild to moderate cases of lymphedema.

Lymphedema in survivors of breast cancer

The tremendous improvement of survival in patients with breast cancer can be attributed to several treatment strategies, but these strategies also lead to the occurrence of breast cancer-related lymphedema (BCRL). BRCL is regularly associated with factors such as axillary lymph node dissection and local lymph node radiotherapy and manifests as an increase of >10% in the volume of affected limbs. Being overweight or having obesity (body mass index ≥25 kg/m2), an excessive number of positive lymph nodes (>8) and capsular invasion by a tumor are additional risk factors for lymphedema. It is worth assessing the risk before surgery as this can prevent the occurrence of BCRL at the initial stage of breast cancer management. The clinical utility of many diagnostic tools and lymphedema surveillance allows early stage and even subclinical BCRL to be diagnosed, and allows real-time monitoring of the disease. The early diagnosis of BRCL allows treatment at an early stage, which is beneficial to the reduction of excess limb volume and the improvement of quality of life. At present, the major therapeutic methods of BCRL include complex decongestive therapy, pneumatic compression devices, participating in exercise, microsurgery and liposuction, each of which alleviates lymphedema effectively. No medications for treatment of BRCL have yet been developed. However, the recent findings on the success of molecular therapy in animal models may remedy this deficiency. Furthermore, the volume reduction of swollen limbs without swelling rebound by transplanting autologous stem cells has been successfully reported in some pilot studies, which may provide a new technique for treating BCRL. This review aimed to discuss the pathogenesis, clinical manifestation, risk factors, advantages and disadvantages of diagnostic tools, lymphedema surveillance and the characteristics of traditional and newly emerging BCRL treatments.

Preoperative Assessment of Upper Extremity Secondary Lymphedema

Introduction: The purpose of this study was to evaluate the most commonly used preoperative assessment tools for patients undergoing surgical treatment for secondary upper extremity lymphedema. Methods: This was a prospective cohort study performed at a tertiary cancer center specializing in the treatment of secondary lymphedema. Lymphedema evaluation included limb volume measurements, bio-impedance, indocyanine green lymphography, lymphoscintigraphy, magnetic resonance angiography, lymphedema life impact scale (LLIS) and upper limb lymphedema 27 (ULL-27) questionnaires. Results: 118 patients were evaluated. Limb circumference underestimated lymphedema compared to limb volume. Bioimpedance (L-Dex) scores highly correlated with limb volume excess (r2 = 0.714, p < 0.001). L-Dex scores were highly sensitive and had a high positive predictive value for diagnosing lymphedema in patients with a volume excess of 10% or more. ICG was highly sensitive in identifying lymphedema. Lymphoscintigraphy had an overall low sensitivity and specificity for the diagnosis of lymphedema. MRA was highly sensitive in diagnosing lymphedema and adipose hypertrophy as well as useful in identifying axillary vein obstruction and occult metastasis. Patients with minimal limb volume difference still demonstrated significantly impaired quality of life. Conclusion: Preoperative assessment of lymphedema is complex and requires multimodal assessment. MRA, L-Dex, ICG, and PROMs are all valuable components of preoperative assessment.

MR Lymphangiography

림프부종의 수술적 치료는 최근 늘어나고 있으며 그에 따른 림프관 평가를 위해 자기공명영상 획득이 증가하고 있다. 전통적인 T2 강조영상에서부터 삼차원 영상에 이르기까지 많은 발전이 이루어지고 있는 분야이다. 삼차원 영상으로는 spoiled gradient echo 영상이 있고 그 변형기법들이 시행되고 있으며 영상에 필수적인 지방억제기법은 최근 mDixon 기법이 각광받고 있다.

Magnetic Resonance Lymphography of Lymphatic Vessels in Upper Extremity With Breast Cancer-Related Lymphedema

BACKGROUND

Magnetic resonance lymphangiography (MRL) has been proven to be able to visualize pathological lymphatic networks and accompanying complications through subcutaneous injection of commonly used contrast agents. However, no comprehensive prior studies have previously been reported regarding MRL for the evaluation of upper extremity lymphedema in patients with breast cancer-related lymphedema (BCRL). In this study, we establish a novel MRL protocol to characterize the normal and abnormal characteristics of different clinical stages of BCRL in patients using high-spatial-resolution MRL.

METHODS

Fifty females with unilateral upper extremity BCRL underwent MRL. Lymphatic vessel morphology in normal and affected limbs was compared. The appearance, distribution pattern, morphologic characteristics, and maximum transversal diameter of the lymphatic vessels, dermal backflow, and regeneration of lymphatic vessels were analyzed.

RESULTS

Lymph fluid was retained in the subcutis of the affected limbs, and no edema was observed in the subfascial compartment. In stage 1, tortuous and dilated lymphatic vessels exhibited a beaded appearance, and their diameters were larger than those in the contralateral forearm (P < 0.05). In stage 2, the dilated lymphatic vessels exhibited larger diameters. "Dermal backflow" and tiny regenerated lymphatic vessels appeared. The thickened subcutaneous tissue showed a honeycomb pattern induced by soft tissue fibrosis and adipose hypertrophy. In stage 3, disordered and unrecognizable affected lymphatic vessels were observed with many small regenerated lymphatics and confluent dermal backflow; the tissue fibrosis was more serious.

CONCLUSIONS

Each stage presents different characteristics, and the deformity degree of the lymphatic network is consistent with the severity of the disease. Magnetic resonance lymphangiography could provide adequate information for clinical staging in patients with BCRL.