Lymphoscintigraphic abnormalities in the contralateral lower limbs of patients with unilateral lymphedema

Rate of Incidental Edema in the Contralateral Arm of Patients with Unilateral Postsurgical Secondary Upper Extremity Lymphedema

Background: Secondary upper extremity lymphedema occurs after an insult such as surgery. One theory suggests underlying lymphatic dysfunction predisposing certain patients into developing secondary lymphedema. We aim to determine the rate of incidental edema in the contralateral upper extremity of patients with secondary unilateral lymphedema. Methods and Results: MRI of the upper extremities were obtained in patients with lymphedema who were referred by a lymphedema clinic from 2017 to 2019. Axial short-tau inversion recovery MR images of the symptomatic and contralateral arms were retrospectively reviewed and edema severity was graded. Interobserver agreement was calculated. Indocyanine green (ICG) lymphography was compared against MRI stage in symptomatic and contralateral. Age, symptom duration, body mass index (BMI), and history of chemotherapy were compared between patients with and without contralateral limb lymphedema. ICG severity was compared against MRI stage. Seventy-eight patients were analyzed. The MRI stages of symptomatic versus contralateral arms were 1.7 ± 1.1 versus 0.1 ± 0.4 (p < 0.00001). Interobserver agreement was 0.86 (0.79-0.94). Of the patients with MRI Stage 1 or above in the symptomatic arm (n = 64), 55 (82.1%) patients demonstrated no abnormality in the contralateral arm. Nine patients (14.1%) demonstrated asymptomatic edema (MRI Stage 1). The mean ICG lymphography stage of symptomatic versus contralateral arms was 1.83 ± 0.96 versus 0.04 ± 0.25 (p < 0.00001). There was no difference in the age, symptom duration, BMI, or history of chemotherapy between patients with or without edema in the contralateral arm. Conclusion: Asymptomatic contralateral edema was detected in 14.1% of patients with unilateral secondary upper extremity lymphedema using MRI modality.

Value of one additional injection at the root of the limb in the lymphoscintigraphic evaluation and management of primary and secondary lower-limb lymphedemas

Introduction

The classical lymphoscintigraphic investigations of lower-limb lymphatic edema [LLLE] sometimes reveal either no or few lymph nodes [LNs] at the root of the limb[s] and/or in the abdomen. The aim of the present paper is to report the results of performing one additional injection at the root of the edematous limb[s] to force the visualization of the LNs and/or to demonstrate the collateral lymphatic pathways in such patients.

Methods and findings

We retrospectively reviewed our database and found 99 patients [44 primary LLLE with 47 limbs injected and 55 with LLLE secondary to treatments for cancer with 64 limbs injected] where such an additional injection had been performed.

In the 43 LLLE patients where no LNs were seen at the end of the classical exam [15 primary LLLE and 28 secondary LLLE], the extra injection showed lymphatic drainage toward LN[s] in all except 3 and when at least one LN was seen, the injection showed lymphatic drainage in every case toward the same ipsilateral [inguinal and/or iliac] LNs [as shown by the classical injection] and/or toward additional LNs.

In 40.7% of patients, we observed one or more additional lymphatic pathways: prepubic superficial lymphatic vessels [LV] crossing the midline anteriorly toward contralateral inguinal LNs in 21 [18.9%], “posterior” LV [toward contralateral inguinal LNs and/or ipsi- or contralateral lumbo-aortic and/or para-renal LNs] in 14 [12.6%], but deep LV toward the ipsilateral common iliac LNs passing between the gluteal muscles in 32 [28.8%].

Conclusion

Our work pinpoints one limitation of classical bipedal radionuclide lymphangiography. In patients with primary and secondary LLLE where inguinal and/or iliac LNs cannot be seen on bipedal radionuclide lymphangiography, this additional injection reveals the true lympho-nodal status and shows unexpected collateral lymphatic pathways in 40% of cases. Such information is of the utmost importance in LLLE management and its acquisition is consequently recommended in these patients.

Lower limb lymphedema staging based on magnetic resonance lymphangiography

OBJECTIVE

Dermal backflow (DBF) and reduced lymphatic visualization are common findings of lymphedema on various imaging modalities. However, there is a lack of knowledge about how these findings vary with the anatomic location and severity of lymphedema, and previous reports using indocyanine green lymphography or lymphoscintigraphy show variable results. Magnetic resonance lymphangiography (MRL) is expected to clarify this clinical question due to its superior ability for lymphatic visualization. This retrospective study aimed to investigate the following: (1) Are there any characteristic patterns for DBF and lymphatics' visualization, depending on the anatomic location within lower limbs and severity of lymphedema? (2) Is it possible to classify the severity of lymphedema based on MRL findings?

METHODS

Two radiologists performed consensus readings of MRL of 56 patients (112 limbs) with lower-limb lymphedema. The frequency of visualized DBF and lymphatics was analyzed in six regions in each lower limb. The results were compared with the International Society of Lymphology clinical stages and etiology of lymphedema. Characteristic findings were categorized and compared with the clinical stage and duration of lymphedema.

RESULTS

DBF and lymphatics were observed more frequently in the distal regions than the proximal regions of lower limbs. DBF appeared more frequently as the clinical stage increased, reaching statistical significance (P < 10^-3) between stages 0 or I and II. DBF above the knee joint was rarely observed (0.48%) in early stages (0 and I) but appeared more frequently (13.5%, P < 10^-5) in stage II. Lymphatics appeared less frequently as the stage progressed, with significant differences (P < .05) between stages I and II and between II and III. The frequency of lymphatics above the knee joint decreased significantly (P < .05) between stages I and II and between II and III as the stage progressed, reaching 0% in stage III. An MRL staging was proposed and showed significant positive correlations with the clinical stage (r = 0.79, P < .01) and the duration of lymphedema (r = 0.57, P < .01).

CONCLUSIONS

MRL-specific patterns of DBF and lymphatics that depended on the site within the lower limb and clinical stage were shown. The DBF pattern differed from those observed in previous studies with other imaging techniques. The proposed MRL staging based on these characteristic findings allows new stratification of patients with lymphedema. Combined with its excellent ability to visualize lymphatic anatomy, MRL could enable a more detailed understanding of individual patient's pathology, useful for determining the most appropriate treatment.

The Development and Treatment of Lymphatic Dysfunction in Cancer Patients and Survivors

Breast-cancer-acquired lymphedema is routinely diagnosed from the appearance of irreversible swelling that occurs as a result of lymphatic dysfunction. Yet in head and neck cancer survivors, lymphatic dysfunction may not always result in clinically overt swelling, but instead contribute to debilitating functional outcomes. In this review, we describe how cancer metastasis, lymph node dissection, and radiation therapy alter lymphatic function, as visualized by near-infrared fluorescence lymphatic imaging. Using custom gallium arsenide (GaAs)-intensified systems capable of detecting trace amounts of indocyanine green administered repeatedly as lymphatic contrast for longitudinal clinical imaging, we show that lymphatic dysfunction occurs with cancer progression and treatment and is an early, sub-clinical indicator of cancer-acquired lymphedema. We show that early treatment of lymphedema can restore lymphatic function in breast cancer and head and neck cancer patients and survivors. The compilation of these studies provides insights to the critical role that the lymphatics and the immune system play in the etiology of lymphedema and associated co-morbidities.

Analysis of collateral lymphatic circulation in patients with lower limb lymphedema using magnetic resonance lymphangiography

OBJECTIVE

Although the development of lymphatic collaterals is expected following lymphedema, little is known about the anatomic details of such compensatory pathways or their association with symptoms. Magnetic resonance lymphangiography (MRL) has been shown to be superior to lymphoscintigraphy and indocyanine green lymphography in visualizing lymphatics. This study aimed to analyze MRL images of lower limbs to elucidate the patterns of lymphatic collateral formation and their association with the clinical stages of lymphedema.

METHODS

We enrolled 56 consecutive patients (112 lower limbs) with lymphedema who underwent MRL. Two radiologists performed a consensus reading of MRL images for the presence or absence of collateral lymphatic pathways, and the results were compared with the clinical stages. Furthermore, the frequency of abnormal MRL findings in 43 asymptomatic lower limbs of patients with unilateral lymphedema was analyzed and compared with that in the 69 symptomatic lower limbs of the patients. The imaging findings were also compared with the cause of lymphedema.

RESULTS

All three collateral pathways (anterolateral, deep, and posteromedial lymphatics) were visualized at a higher (P < .05) frequency in stage II than in stage 0 lower limbs. The frequency of visualization of the three collaterals was significantly higher in symptomatic (stages I-III) lower limbs than in asymptomatic (stage 0) lower limbs. Most (76.8%) of the symptomatic limbs exhibited at least one of these collaterals, and the frequency was significantly higher than in the asymptomatic limbs (P < .001). Most (81.4%) of the asymptomatic (stage 0) lower limbs had at least one abnormal finding in terms of lymphatic circulation, although this proportion was significantly lower compared with the symptomatic limbs (98.6%). The collaterals tended to appear less frequently in primary lymphedema than in secondary lymphedema, reaching statistical significance in the posteromedial lymphatics.

CONCLUSIONS

These results suggested that the two superficial lymphatic groups and the deep lymphatic system act as major collaterals of the lower limbs in patients with lymphedema. Furthermore, MRL of most patients with unilateral lymphedema demonstrated abnormal findings, including collateral formation, not only in the affected lower limb but also in the asymptomatic lower limb. In primary lymphedema, the collaterals may appear less frequently than in secondary lymphedema. Collaterals should be taken into consideration in planning the site of lymphaticovenous anastomosis and assessing disease progression. MRL can visualize preclinical alterations in lymphatic flow and compensatory pathways; therefore, we expect that it will be useful for the early diagnosis of lymphedema.

Effects of mobilized peripheral blood stem cells on treatment of primary lower extremity lymphedema

OBJECTIVE

Lymphedema is a chronic debilitating disease characterized by the accumulation of fluid in the extremities as a result of lymphatic system impairment. Current treatments fail to restore the functionality and structural integrity of the lymphatic vessels lost in this condition. In this study, autologous mobilized peripheral blood stem cell transplantation was used and its potential efficacy and safety were evaluated in treating this condition.

METHODS

Ten patients with primary lymphedema in the lower extremity received granulocyte-colony stimulating factor subcutaneously for 4 days, to stimulate stem cell mobilization, after which 200 to 250 mL of blood was drawn from each patient and used to collect stem cells. Mobilized stem cells were counted by flow cytometry with International Society of Hematotherapy and Graft Engineering method. In two sessions, 3 weeks apart, these stem cells were injected subcutaneously in the affected limb at approximately 80 points, along the lymphatic vessels. Each patient was followed for 6 months, during which changes in the limb volume and circumference were measured. Lymphangiogenesis was evaluated by biopsy, the lymphoscintigraphic transport index was calculated using Lymphoscintigraphy, and quality of life was surveyed.

RESULTS

In this study, patients received on average 9.5 ± 6.8 × 10⁸ mononuclear cells (which divided into 2 × 10⁶ CD34⁺ cells for each session) in two sessions. The volume of the lower limbs decreased in 60% of patients. One patient showed a slight increase in the volume of lower limbs and three showed no change. The average limb volume was 4469.41 ± 1760.71 cm³, which on average differed from the average initial limb volume by 232.88 ± 392.53 cm³. Quality of life was reported as slightly increased in 60% of patients. The lymphoscintigraphic transport index suggested improvement in 60% of the patients. Likewise, tissue samples showed a 60% increase in lymphatic vessels.

CONCLUSIONS

Subcutaneous injection of autologous hematopoietic stem cells harvested from peripheral blood into patients with primary lower limb lymphedema is feasible, potentially effective, and without serious adverse effects. However, a larger scale study with more patients is needed to validate our results. Last, to increase the effectiveness of this treatment, the optimal dose of cells injected and the requirement for additional growth factors need further study.

Prostate-Specific Membrane Antigen Accumulation in Lower Extremity Lymphedema

Prostate-specific membrane antigen (PSMA) is overexpressed in a majority of prostate cancer cells, which has led to the development of radiolabeled small-molecule inhibitors of PSMA for molecular imaging and targeted radioligand therapy. Lu-labeled PSMA, with therapeutic β-emission and concomitant γ radiation, permits posttherapy imaging for the assessment of biodistribution and uptake in tumors and normal organs, as well as dosimetry. We report a patient with prostate cancer and metastatic lymph nodes-related lower extremity lymphedema, who presented with dermal backflow and soft-tissue uptake in the lower extremity on posttherapeutic whole body scan after intravenous Lu-PSMA treatment.

3.0 T relaxation time measurements of human lymph nodes in adults with and without lymphatic insufficiency: Implications for magnetic resonance lymphatic imaging

The purpose of this work was to quantify 3.0 T (i) T1 and T2 relaxation times of in vivo human lymph nodes (LNs) and (ii) LN relaxometry differences between healthy LNs and LNs from patients with lymphatic insufficiency secondary to breast cancer treatment-related lymphedema (BCRL). MR relaxometry was performed over bilateral axillary regions at 3.0 T in healthy female controls (105 LNs from 20 participants) and patients with BCRL (108 LNs from 20 participants). Quantitative T1 maps were calculated using a multi-flip-angle (20, 40, 60°) method with B1 correction (dual-TR method, TR1 /TR2  = 30/130 ms), and T2 maps using a multi-echo (TE  = 9-189 ms; 12 ms intervals) method. T1 and T2 were quantified in the LN cortex and hilum. A Mann-Whitney U-test was applied to compare LN relaxometry values between patients and controls (significance, two sided, p < 0.05). Linear regression was applied to evaluate how LN relaxometry varied with age, BMI, and clinical indicators of disease. LN substructure relaxation times (mean ± standard deviation) in healthy controls were T1 cortex, 1435 ± 391 ms; T1 hilum, 714 ± 123 ms; T2 cortex, 102 ± 12 ms, and T2 hilum, 119 ± 21 ms. T1 of the LN cortex was significantly reduced in the contralateral axilla of BCRL patients compared with the axilla on the surgical side (p < 0.001) and compared with bilateral control values (p < 0.01). The LN cortex T1 asymmetry discriminated cases from controls (p = 0.004) in a multiple linear regression, accounting for age and BMI. Human 3.0 T T1 and T2 relaxation times in axillary LNs were quantified for the first time in vivo. Measured values are relevant for optimizing acquisition parameters in anatomical lymphatic imaging sequences, and can serve as a reference for novel functional and molecular LN imaging methods that require quantitative knowledge of LN relaxation times.