Longitudinal monitoring of the head and neck lymphatics in response to surgery and radiation

Prognostic Factors and Outcomes Associated With Neck Lymphedema in Head and Neck Cancer Survivors

OBJECTIVES

The purpose of this study is to determine the predictors of neck lymphedema and to explore its association with symptoms and patient-reported outcomes (PROs) in Head and Neck Cancer (HNC) patients who underwent non-operative treatment.

METHODS

This study involved a cross-sectional secondary analysis of data from patients diagnosed with head and neck squamous cell carcinoma who underwent radiation therapy (±chemotherapy). Patients with visits <6 weeks or >2 years following completion of radiation and those with recurrent or metastatic cancer were excluded. Presence of post-treatment lymphedema, demographics, clinical characteristics, health-related behaviors, and symptoms were collected. PROs were obtained using validated questionnaires that assessed depression, anxiety, swallowing dysfunction, and quality of life (QOL). Multivariable regression models were used to examine the relationship between lymphedema with predictors and symptoms.

RESULTS

Of the 203 patients included, 88 (43.4%) developed post-treatment lymphedema. In multivariable analysis, pre-treatment Body Mass Index (BMI) (odds ratio [OR] = 1.07, 95% confidence interval [CI] [1.01, 1.14] p = 0.016) and N stage (OR = 1.96, 95% CI [1.06, 3.66], p = 0.032) were found to be independently associated with lymphedema. Regarding PROs, lymphedema was associated with greater swallowing dysfunction (3.48, 95% CI [0.20, 6.75], p = 0.038), decreased mouth opening (-3.70, 95% CI [-7.31, -0.10], p = 0.044), and increased fatigue (1.88, 95% CI [1.05, 3.38], p = 0.034).

CONCLUSION

Higher pre-treatment BMI and greater N stage are identified as independent predictors for lymphedema development in non-operative HNC patients. Additionally, patients experiencing lymphedema reported worsening swallowing dysfunction and increased symptoms related to trismus and fatigue. Recognizing patients at elevated risk for lymphedema allows for early intervention, alleviation of symptom burden, and optimization of health care resources.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3656-3663, 2024.

Managing lymphoedema following treatment for head and neck cancer: is complete decongestive therapy an effective intervention to improve dysphagia outcomes?

PURPOSE OF REVIEW

The purpose of this review is to summarize current evidence regarding management of head and neck lymphoedema (HNL) to improve dysphagia outcomes following head and neck cancer (HNC) treatment. This review aims to support complete decongestive therapy (CDT) comprising compression, manual lymphatic drainage (MLD), exercises and skincare as an adjunct of dysphagia rehabilitation.

RECENT FINDINGS

Research in the limbs supports the use of CDT to improve lymphoedema outcomes. Emerging evidence supports the use of CDT for the head and neck, though, there is no consensus on optimal treatment required to improve dysphagia outcomes. Current evidence is limited due to a paucity of randomized controlled trials, case series or cohort studies with small participant numbers, and a lack of functional and instrumental dysphagia outcome measures. This provides a foundation to design and test an individually tailored programme of HNL intervention to evaluate swallowing outcomes post CDT.

SUMMARY

As the incidence of HNC is increasing with HPV, with patients living for longer with late effects of HNC treatment, it is vital to understand how the presence of HNL impacts on the swallow, and if functional dysphagia outcomes improve following treatment of HNL. Prospective, longitudinal research with objective and functional outcome measures are required to help determine optimal management of HNL and its impact on the swallow.

Determining risk and predictors of head and neck cancer treatment-related lymphedema: A clinicopathologic and dosimetric data mining approach using interpretable machine learning and ensemble feature selection

Background and purpose

The ability to determine the risk and predictors of lymphedema is vital in improving the quality of life for head and neck (HN) cancer patients. However, selecting robust features is challenging due to the multicollinearity and high dimensionality of radiotherapy (RT) data. This study aims to overcome these challenges using an ensemble feature selection technique with machine learning (ML).

Materials and methods

Thirty organs-at-risk, including bilateral cervical lymph node levels, were contoured, and dose-volume data were extracted from 76 HN treatment plans. Clinicopathologic data was collected. Ensemble feature selection was used to reduce the number of features. Using the reduced features as input to ML and competing risk models, internal and external lymphedema prediction capability was evaluated with the ML models, and time to lymphedema event and risk stratification were estimated using the risk models.

Results

Two ML models, XGBoost and random forest, exhibited robust prediction performance. They achieved average F1-scores and AUCs of 84 ± 3.3 % and 79 ± 11.9 % (external lymphedema), and 64 ± 12 % and 78 ± 7.9 % (internal lymphedema). Predictive ML and risk models identified common predictors, including bulky node involvement, high dose to various lymph node levels, and lymph nodes removed during surgery. At 180 days, removing 0-25, 26-50, and > 50 lymph nodes increased external lymphedema risk to 72.1 %, 95.6 %, and 57.7 % respectively (p = 0.01).

Conclusion

Our approach, involving the reduction of HN RT data dimensionality, resulted in effective ML models for HN lymphedema prediction. Predictive dosimetric features emerged from both predictive and competing risk models. Consistency with clinicopathologic features from other studies supports our methodology.

Imaging peripheral lymphatic dysfunction in chronic conditions

The lymphatics play important roles in chronic diseases/conditions that comprise the bulk of healthcare worldwide. Yet the ability to routinely image and diagnose lymphatic dysfunction, using commonly available clinical imaging modalities, has been lacking and as a result, the development of effective treatment strategies suffers. Nearly two decades ago, investigational near-infrared fluorescence lymphatic imaging and ICG lymphography were developed as routine diagnostic for clinically evaluating, quantifying, and treating lymphatic dysfunction in cancer-related and primary lymphedema, chronic venous disease, and more recently, autoimmune and neurodegenerative disorders. In this review, we provide an overview of what these non-invasive technologies have taught us about lymphatic (dys) function and anatomy in human studies and in corollary animal studies of human disease. We summarize by commenting on new impactful clinical frontiers in lymphatic science that remain to be facilitated by imaging.

A prospective observational cohort study examining the development of head and neck lymphedema from the time of diagnosis

INTRODUCTION

Head and neck lymphedema can occur in the internal or external structures of the head and neck region. Little is known about the development of this condition over the course of treatment for head and neck cancer. This study aimed to observe the development of internal and external lymphedema from diagnosis to 12 weeks postacute treatment.

METHODS

A single center, prospective observational cohort study assessed participants for external lymphedema, internal lymphedema, quality of life, and symptom burden. Assessments were conducted prior to starting radiotherapy (RT), at the end of RT, 6 and 12 weeks after RT.

RESULTS

Forty-six participants were recruited. External lymphedema as measured by percentage water content, increased from 41.9 at baseline (95% CI: 39.3-44.4) to 50.4 (95% CI: 46.0-54.8) at 12 weeks following RT (p-value < .001). After adjusting for changes in weight and participant age at baseline, a general increase in tape measurements was observed over time with significant increases from baseline to 12 weeks post-RT for all measurement points. By 12 weeks post-RT, all participants had lymphedema present in eight of 13 internal sites assessed.

CONCLUSIONS

Internal and external head and neck lymphedema was observed to increase from baseline to 12 weeks after completion of RT without abatement. People with head and neck cancer should be educated about the potentially extended duration of this treatment side effect. Further research is required to determine the point at which swelling symptoms recede.

Prediction of breast cancer-related lymphedema by dermal backflow detected with near-infrared fluorescence lymphatic imaging

PURPOSE

Mild breast cancer-related lymphedema (BCRL) is clinically diagnosed as a 5%-10% increase in arm volume, typically measured no earlier than 3-6 months after locoregional treatment. Early BCRL treatment is associated with better outcomes, yet amid increasing evidence that lymphedema exists in a latent form, treatment is typically delayed until arm swelling is obvious. In this study, we investigated whether near-infrared fluorescence lymphatic imaging (NIRF-LI) surveillance could characterize early onset of peripheral lymphatic dysfunction as a predictor of BCRL.

METHODS

In a prospective, longitudinal cohort/observational study (NCT02949726), subjects with locally advanced breast cancer who received axillary lymph node dissection and regional nodal radiotherapy (RT) were followed serially, between 2016 and 2021, before surgery, 4-8 weeks after surgery, and 6, 12, and 18 months after RT. Arm volume was measured by perometry, and lymphatic (dys) function was assessed by NIRF-LI.

RESULTS

By 18 months after RT, 30 of 42 study subjects (71%) developed mild-moderate BCRL (i.e., ≥ 5% arm swelling relative to baseline), all manifested by "dermal backflow" of lymph into lymphatic capillaries or interstitial spaces. Dermal backflow had an 83% positive predictive value and 86% negative predictive value for BCRL, with a sensitivity of 97%, specificity of 50%, accuracy of 83%, positive likelihood ratio of 1.93, negative likelihood ratio of 0.07, and odds ratio of 29.00. Dermal backflow appeared on average 8.3 months, but up to 23 months, before the onset of mild BCRL.

CONCLUSION

BCRL can be predicted by dermal backflow, which often appears months before arm swelling, enabling early treatment before the onset of edema and irreversible tissue changes.

Fluorescent Tracers for In Vivo Imaging of Lymphatic Targets

The lymphatic system continues to gain importance in a range of conditions, and therefore, imaging of lymphatic vessels is becoming more widespread for research, diagnosis, and treatment. Fluorescent lymphatic imaging offers advantages over other methods in that it is affordable, has higher resolution, and does not require radiation exposure. However, because the lymphatic system is a one-way drainage system, the successful delivery of fluorescent tracers to lymphatic vessels represents a unique challenge. Each fluorescent tracer used for lymphatic imaging has distinct characteristics, including size, shape, charge, weight, conjugates, excitation/emission wavelength, stability, and quantum yield. These characteristics in combination with the properties of the target tissue affect the uptake of the dye into lymphatic vessels and the fluorescence quality. Here, we review the characteristics of visible wavelength and near-infrared fluorescent tracers used for in vivo lymphatic imaging and describe the various techniques used to specifically target them to lymphatic vessels for high-quality lymphatic imaging in both clinical and pre-clinical applications. We also discuss potential areas of future research to improve the lymphatic fluorescent tracer design.

Systematic review of head and neck lymphedema assessment

Head and neck lymphedema (HNL) is an increasingly recognized complication of head and neck cancer and its treatment. However, no consensus exists on the "gold-standard" assessment tool for the purposes of diagnosis, classification, or monitoring of HNL. We conducted a systematic review of the literature regarding HNL assessment to determine the optimal method/s of assessment for patients with HNL. A review of publications between January 2000 and September 2021 was undertaken on four electronic databases. Studies were excluded if no clear assessment method of HNL was documented. Sixty-seven articles were included in the study. A wide range of assessment methods for HNL have been reported in the literature. For the purposes of diagnosis and classification of physical findings, computed tomography (CT) appears the most promising tool available for both external and internal HNL. In terms of monitoring, ultrasound appears optimal for external HNL, while a clinician-reported rating scale on laryngoscopy is the gold standard for internal HNL. Patient-reported assessment must be considered alongside objective methods to classify symptom burden and monitor improvement with treatment.

Lymphatic function and anatomy in early stages of lipedema

OBJECTIVE

Lipedema is an inflammatory subcutaneous adipose tissue disease that develops in women and may progress to lipolymphedema, a condition similar to lymphedema, in which lymphatic dysfunction results in irresolvable edema. Because it has been shown that dilated lymphatic vessels, impaired pumping, and dermal backflow are associated with presymptomatic, cancer-acquired lymphedema, this study sought to understand whether these abnormal lymphatic characteristics also characterize early stages of lipedema prior to lipolymphedema development.

METHODS

In a pilot study of 20 individuals with Stage I or II lipedema who had not progressed to lipolymphedema, lymphatic vessel anatomy and function in upper and lower extremities were assessed by near-infrared fluorescence lymphatic imaging and compared with that of a control population of similar age and BMI.

RESULTS

These studies showed that, although lower extremity lymphatic vessels were dilated and showed intravascular pooling, the propulsion rates significantly exceeded those of control individuals. Upper extremity lymphatics of individuals with lipedema were unremarkable. In contrast to individuals with lymphedema, individuals with Stage I and II lipedema did not exhibit dermal backflow.

CONCLUSIONS

These results suggest that, despite the confusion in the diagnoses between lymphedema and lipedema, their etiologies differ, with lipedema associated with lymphatic vessel dilation but not lymphatic dysfunction.

Enhanced T-Cell Priming and Improved Anti-Tumor Immunity through Lymphatic Delivery of Checkpoint Blockade Immunotherapy

An infusion of checkpoint blockade immunotherapy (CBI) has revolutionized cancer treatments for some patients, but the majority of patients experience disappointing responses. Because adaptive immune responses are mounted by the concentrated assembly of antigens, immune cells, and mediators in the secluded and protective environment of draining lymph nodes (dLNs), we hypothesize that lymphatic delivery of CBI (αCTLA-4 and αPD-1) to tumor dLNs (tdLNs) improves anti-tumor responses over intravenous (i.v.) administration, and that vaccination against tumor associated antigen (TAA) further enhances these responses. Mono- and combination CBI were administered i.v. or through image-guided intradermal (i.d.) injection to reach tdLNs in vaccinated and unvaccinated animals bearing either primary or orthotopically metastasizing B16F10 melanoma. Vaccination and boost against TAA, Melan-A, was accomplished with virus-like particles (VLP) directed to tdLNs followed by VLP boost after CBI administration. Lymphatic delivery of CBIs reduced primary tumor size and metastatic tumor burden, alleviated the pro-tumorigenic immune environment, and improved survival over systemic administration of CBIs. Animals receiving CBIs lymphatically exhibited significantly enhanced survival over those receiving therapies administered partially or completely through systemic routes. By combining vaccination and CBI for effective T-cell priming in the protected environment of dLNs, anti-tumor responses may be improved.

Degradation of lymphatic anatomy and function in early venous insufficiency

OBJECTIVE

We used near-infrared fluorescence lymphatic imaging in a pilot study to assess the lymphatics in preulcerative (C2-C4) venous insufficiency and determine whether involvement and/or degradation of lymphatic anatomy or function could play a role in the progression of chronic venous insufficiency. We also explored the role of lymphatics in early peripheral arterial disease.

METHODS

After informed consent and intradermal injections of indocyanine green for rapid lymphatic uptake, near-infrared fluorescence lymphatic imaging was used to assess the lymphatic anatomic structure and quantify the lymphatic propulsion rates in subjects with early venous insufficiency. The anatomic observations included interstitial backflow, characterized by the abnormal spreading of indocyanine green from the injection site primarily into the surrounding interstitial tissues; dermal backflow, characterized by the retrograde movement of dye-laden lymph from collecting lymphatics into the lymphatic capillaries; and lymphatic vessel segmentation and dilation.

RESULTS

Ten subjects with venous insufficiency were enrolled, resulting in two legs with C2 disease, nine legs with C3 disease, eight legs with C4 disease, and one leg with C5 disease. Interstitial and/or dermal backflow were observed in 25%, 33%, and 41% of the injection sites in each limb with C2, C3, and C4 disease, respectively. Distinct vessel segmentation and dilation were observed in limbs with a C3 and higher classification, and dermal backflow proximal to the injection sites was observed in two legs with C4 disease and in the inguinal region of the C5 study subject. The overall average lymph propulsion rates were 1.3 ± 0.4, 1.2 ± 0.7, and 0.8 ± 0.5 contractile events/min for limbs with C2, C3, and C4 disease, respectively. One subject with peripheral arterial disease, who had previously undergone bypass surgery, presented with extensive dermal backflow and lymphatic reflux.

CONCLUSIONS

Near-infrared fluorescence lymphatic imaging demonstrated that, compared with normal health subjects, the lymphatic anatomy and contractile function generally degrade with the severity of venous insufficiency. Lymphatic abnormalities mimic those in early cancer-acquired lymphedema subjects, as previously observed by us and others. Additional studies are needed to decipher the relationship, including any causality, between lymphatic dysfunction and peripheral vascular disease and venous insufficiency.

Lymphatic Dissemination and Axillary Web Syndrome in Primary Cutaneous Tuberculosis Secondary to Needlestick Injury

Cutaneous tuberculosis secondary to skin inoculation of Mycobacterium tuberculosis is uncommon but it can occur in the health care settings. Herein, we report an unusual case of primary cutaneous tuberculosis of the thumb following a needlestick injury. The infection progressed with a necrotic granuloma, lymphatic dysfunction as visualized by near-infrared fluorescence lymphatic imaging, and the development of an axillary web syndrome.

Assessing lymphatic route of CSF outflow and peripheral lymphatic contractile activity during head-down tilt using near-infrared fluorescence imaging

Evidence overwhelmingly suggests that the lymphatics play a critical role in the clearance of cerebrospinal fluid (CSF) from the cranial space. Impairment of CSF outflow into the lymphatics is associated with a number of pathological conditions including spaceflight‐associated neuro‐ocular syndrome (SANS), a problem that limits long‐duration spaceflight. We used near‐infrared fluorescence lymphatic imaging (NIRFLI) to dynamically visualize the deep lymphatic drainage pathways shared by CSF outflow and disrupted during head‐down tilt (HDT), a method used to mimic the cephalad fluid shift that occurs in microgravity. After validating CSF clearance into the lymph nodes of the neck in swine, a pilot study was conducted in human volunteers to evaluate the effect of gravity on the flow of lymph through these deep cervical lymphatics. Injected into the palatine tonsils, ICG was imaged draining into deep jugular lymphatic vessels and subsequent cervical lymph nodes. NIRFLI was performed under HDT, sitting, and supine positions. NIRFLI shows that lymphatic drainage through pathways shared by CSF outflow are dependent upon gravity and are impaired under short‐term HDT. In addition, lymphatic contractile rates were evaluated from NIRFLI following intradermal ICG injections of the lower extremities. Lymphatic contractile activity in the legs was slowed in the gravity neutral, supine position, but increased under the influence of gravity regardless of whether its force direction opposed (sitting) or favored (HDT) lymphatic flow toward the heart. These studies evidence the role of a lymphatic contribution in SANS.

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.

Prognostic factors for lymphedema in patients with locally advanced head and neck cancer after combined radio(chemo)therapy- results of a longitudinal study

AIM

Treatment-associated lymphedema is a common side effect after multimodal therapy for locally advanced head and neck cancer (LAHNC). This study aims to evaluate potential prognostic factors for head and neck lymphedema (HNL) and its potential impact on clinical outcome.

METHODS

This is a prospective data registry analysis on 280 patients treated for locally advanced head and neck cancer (LAHNC). All patients received surgery and risk-adapted platinum-based adjuvant intensity modulated radio(chemo)therapy (R(C)T, IMRT). Treatment- related toxicity was prospectively registered in a data base in regular intervals (baseline 3 months after R(C)T, every 3 months for 3 years, and every 6 months thereafter) and documented according to RTOG/EORTC toxicity criteria.

RESULTS

Predictive for any grade HNL 3 months after R(C)T were age, BMI, number of removed nodes and RT modality. Multivariable logistic regression analysis showed that in the acute toxicity phase (3 months after R(C)T) higher body mass index (BMI), extracapsular spread (ECE), linac-based IMRT, bilateral treatment to the neck (surgery and RT), and the addition of chemotherapy increase the risk for grade 2 HNL. For chronic HNL, higher BMI, linac-based IMRT and ECE were predictive for grade 2 HNL. Higher BMI is associated with better local control rates. Advanced age and ECE had a negative impact on OS.

CONCLUSION

HNL is a common acute and late side effect after multimodal therapy for LAHNC. Knowing risk factors for HNL prior to therapy enables caregivers and patients to take measures prior to treatment to prevent or limit the effects of HNL.

Treatment for lymphedema following head and neck cancer therapy: A systematic review

OBJECTIVE

To perform the first systematic review evaluating all established treatment modalities of head and neck lymphedema resulting from head and neck cancer therapy. Since craniofacial lymphedema treatment represents unique challenges not addressed by extremity lymphedema therapies, a systematic review and evaluation of treatment modalities specific to this area is needed to guide clinical management and further research.

DATA SOURCES

Four electronic databases were searches from inception to September 2018. These included Scopus (Embase), PubMed (Medline), Clinicaltrials.gov, and Cochrane Databases.

REVIEW METHODS

A search string was developed, and all databases queried for keywords on three subjects: head and neck cancer, lymphedema, and therapy. Results were uploaded to an EndNote database where relevant items were identified by hand-searching all titles and abstracts. Subsequently results were combined, duplicates removed, and full papers screened according to eligibility criteria.

RESULTS

Of a total 492 search results, twenty-six items met eligibility criteria for this review. These included fourteen cohort studies, seven case reports, two randomized controlled trials, two systematic reviews, and one narrative review totaling 1018 study subjects. The manual lymph drainage group had the largest number of studies and participants, with fewer studies investigating selenium, liposuction, and lymphaticovenular anastomosis.

CONCLUSION

Evidence for the efficacy of all types of lymphedema therapy is limited by paucity of large randomized controlled trials. While manual lymph drainage is best studied, liposuction and surgical treatments have also been effective in a small number of patients.

Head and Neck Lymphedema: Treatment Response to Single and Multiple Sessions of Advanced Pneumatic Compression Therapy

Ten head and neck cancer survivors diagnosed with head and neck lymphedema (HNL) were imaged using near-infrared fluorescence lymphatic imaging (NIRFLI) prior to and immediately after an initial advance pneumatic compression device treatment and again after 2 weeks of daily at-home use. Images assessed the impact of pneumatic compression therapy on lymphatic drainage. Facial composite measurement scores assessed reduction/increase in external swelling, and survey results were obtained. After a single pneumatic compression treatment, NIRFLI showed enhanced lymphatic uptake and drainage in all subjects. After 2 weeks of daily treatment, areas of dermal backflow disappeared or were reduced in 6 of 8 subjects presenting with backflow. In general, reductions in facial composite measurement scores tracked with reductions in backflow and subject-reported improvements; however, studies are needed to determine whether longer treatment durations can be impactful and whether advanced pneumatic compression can be used to ameliorate backflow characteristic of HNL.

Near-infrared fluorescence lymphatic imaging in vascular endothelial growth factor-C overexpressing murine melanoma

In this study we employ a near-infrared fluorescence lymphatic imaging (NIRFLI) technique to longitudinally image spatial and temporal changes in the lymphatics in mice bearing vascular endothelial growth factor (VEGF)-C overexpressing B16F10 (VEGF-C-B16F10) or mock-transduced B16F10 (mock-B16F10) melanoma tumors. Our NIRFLI data show that ICG-laden lymph accumulates into a VEGF-C-B16F10 tumor compared to mock-B16F10 at 3 days post implantation, presumably due to increased lymphatic vessel permeability. Quantification shows a significantly greater percentage of ICG-perfused area in VEGF-C-B16F10 (7.6 ± 2) as compared to MOCK-B16F10 (1 ± 0.5; p = 0.02), which is also confirmed by quantification of the lymphatic leakage of evans blue dye (optical density at 610nm; VEGF-C-B16F10, 10.5 ± 2; mock-B16F10, 5.1 ± 0.5; p = 0.009); thereafter, lymphatic leakage is visualized only in the peritumoral region. Our imaging data also show that anti-VEGF-C treatment in VEGF-C-B16F10 restores normal lymphatic vessel integrity and reduces dye extravasation. Because NIRFLI technology can be used to non-invasively detect lymphatic changes associated with cancer, it may provide a new diagnostic to assess the lack of lymphatic vessel integrity that promotes lymphovascular invasion and to assess therapies that could arrest invasion through normalization of the lymphatic vasculature.