Understanding the water content of skin and subcutaneous tissue is central to diagnosing and managing numerous medical conditions. One of the validated methods for doing this is Tissue Dielectric Constant (TDC) measurement, which offers non-invasive, real-time insights into local tissue water content.
Developed for clinical lymphedema assessment, TDC technology has evolved into a powerful tool for both clinical practice and medical research. At Delfin Technologies, we are proud to offer handheld TDC devices like the LymphScanner, designed for precision, portability, and ease of use in both point-of-care and research settings.
A 2023 review by Dr. Harvey Mayrovitz in Cureus underscores the versatility and reliability of TDC methods — especially for lymphedema detection and monitoring, and highlights a wide array of potential research applications in other fields of medicine.
TDC in Clinical Practice: Objective Assessment of Lymphedema
Lymphedema — particularly in breast cancer survivors and other cancer patients — presents a critical need for early detection and reliable monitoring. Traditional methods like limb circumference and water displacement are either too general, too cumbersome, or not sensitive enough to detect early-stage or localized fluid accumulation.
TDC measurement addresses these limitations by providing:
- Localized, quantitative assessment of tissue water content
- Rapid, non-invasive readings (in seconds)
- Portability, enabling bedside or outpatient clinic use
- Sensitivity to even subclinical lymphedema
Validated Clinical Applications: Localized, Objective Lymphedema Assessment
TDC measurement has been validated across a range of clinical lymphedema scenarios — enabling fast, objective assessments that support clinical decisions and improve patient outcomes.
Breast Cancer-Related Arm and Breast Edema (BCRL)
TDC technology was first introduced to assess arm lymphedema in breast cancer survivors, and has since proven useful in detecting both arm and breast tissue changes after surgery and radiotherapy. Its ability to quantify percentage water content (PWC) offers clinicians a sensitive tool for:
- Detecting preclinical lymphedema before visual swelling
- Tracking treatment response to compression or manual lymph drainage
- Assessing localized breast edema, often overlooked using standard methods
Lower Limb Lymphedema: Unilateral and Bilateral Cases
TDC is well suited for evaluating lower extremity lymphedema, where anatomical variability and bilateral involvement often complicate standard measurements. Clinical protocols can utilize:
- Side-to-side comparisons when only one leg is affected
- Arm-to-Leg PWC ratios in case of bilateral swelling
- Validated measurement sites including medial/lateral calf, foot, and thigh
This enables clinicians to localize edema with precision and track subtle improvements or deterioration over time.
Midline and Trunk Edema
Edema in central body regions — such as the chest wall, axilla, abdomen, or thorax — is notoriously difficult to measure with circumference or volume-based tools. Mayrovitz highlights TDC as one of the few practical methods for evaluating midline and trunk lymphedema, including post-radiation edema in the chest and abdomen.
Head and Neck Lymphedema (HNL)
TDC measurement has shown increasing promise in the evaluation of head and neck lymphedema, particularly in following treatment effects in lymphedema with head and neck cancer patients and survivors:
- Existing protocols for head and neck assessments
- Repeatable, localized measurements during recovery and therapy follow-up
How It Works
At 300 MHz, the TDC probe sends a low-power electromagnetic signal into the skin. Water has a high dielectric constant, so the reflected signal correlates directly with local tissue hydration.
The result: an objective, numerical value indicating percentage water content (PWC) — a key metric in evaluating edema severity, guiding clinical interventions, and tracking treatment response.
This simple, yet scientifically grounded principle enables fast, reproducible measurements without discomfort or invasive procedures.
Beyond Lymphedema: Opportunities in Medical Research
While lymphedema detection is the most established clinical application, Mayrovitz’s review also outlines emerging research opportunities where TDC could offer valuable insights:
Potential Research Applications:
- Diabetic skin assessment: Investigating microcirculation and hydration
- Wound healing: Monitoring hydration dynamics in chronic wounds
- Dermatology and barrier function: Evaluating inflammatory skin conditions
- Cardiac and pulmonary edema: Exploring tissue-level fluid changes
- Radiation-induced fibrosis: Studying hydration shifts in fibrotic tissue
As a validated, portable measurement modality, TDC is gaining traction in translational medicine, clinical trials, and exploratory studies — providing a versatile platform for skin and soft tissue science.
References:
Mayrovitz. 2023. Medical Applications of Skin Tissue Dielectric Constant Measurements
https://pmc.ncbi.nlm.nih.gov/articles/PMC10787628/
Conclusion
A Platform for Precision, Portability and Progress
TDC measurement is no longer just a research tool — it’s a clinically valuable, field-proven solution for objective edema assessment. With Delfin’s LymphScanner, healthcare providers gain access to real-time, actionable data that improves diagnostics, enhances therapy monitoring, and supports evidence-based care.
At the same time, medical researchers are leveraging the same technology to explore new frontiers in skin and soft tissue science — including breast edema, lower limb lymphedema, head and neck swelling, and midline edema.
Whether you're treating lymphedema or designing the next clinical study, Delfin's TDC devices empower you with precision you can trust — in the palm of your hand.
