Ultrasonographic Evaluation of Breast Cancer-related Lymphedema

Summary

This study utilized ultrasonography for diagnosis and follow-up tests to confirm treatment efficacy of Progressive Resistance Exercise (PRE) in breast cancer-related lymphedema (BCRL). Ultrasonography can be applied effectively to ensure diagnosis and treatment of lymphedema.

Abstract

Lymphedema is one of the most common complications after breast cancer surgery. There are many diagnostic tools for lymphedema, but no standard method yet exists. Progressive Resistance Exercise (PRE) is expected to improve lymphedema without additional swelling. This study showed the therapeutic effects of PRE on lymphedema by using ultrasonography to measure the change in thickness of the muscle and subcutaneous tissue. The thickness of subcutaneous tissue decreased more in the PRE group than in the non-PRE group. Ultrasonography is widely used in many clinics because of its easy accessibility, safety, and inexpensiveness. Ultrasound is one of the best tools for diagnosing and determining treatment efficacy on breast cancer-related lymphedema (BCRL).

Introduction

Lymphedema is defined as a condition of localized protein-rich fluid retention and tissue swelling caused by a compromised lymphatic system^1,2. As lymphedema progresses, fibrocytes and/or adipocytes proliferate in the affected areas, leading to changes in the texture of the skin and subcutaneous tissue and an increased vulnerability to bacterial and fungal infections^3,4. The observation of these changes in various parts of the extremities may further elucidate the severity and extent of lymphedema. The subfascial lymphatic system contributes to the severity of lymphedema more than the epifascial lymphatic system.

Recent research has mainly focused on the use of ultrasonography in the diagnosis of lymphedema^5,6. Ultrasonography is a relatively inexpensive method to observe soft-tissue characteristics. A previous study reported that lymphedema can be reliably diagnosed with ultrasonography by comparing the thickness of the skin and subcutaneous tissue and also by evaluating the compliance of the subcutaneous tissue in a clinical setting^7,8. In addition, ultrasonography is widely used in the clinic because of its easy accessibility, safety from radiation exposure, and inexpensiveness^5,6. In spite of these benefits, studies on ultrasonography for lymphedema have only been focused on diagnosis, not on evaluation of therapeutic intervention.

Therefore, the current study aimed to determine not only the usefulness of ultrasonography in elucidating the effects of PRE on BCRL, but also whether ultrasonography has a clinical significance as a follow-up test in confirming treatment efficacy. This study was conducted to establish the protocol for ultrasounds performed to examine lymphedema.

Protocol

All of the procedures were reviewed and approved by the Institutional Review Board of Chungnam National University Hospital.

1. Measurement with Ultrasonography

1. Set the posture of the patient.
   1. Lay the patient's arm in a supine position, with both arms on the bed.
2. Determine the measurement sites on the patient's upper limb.
   1. Mark in the mid-point of the wrist crease, the mid-point between the medial and lateral epicondyles at the level of the elbow, and the bicipital groove by a pen.
   2. Using a pen directly connect these three points by a ruler. Mark the two target areas on the upper arm and forearm (Figure 1).
      1. Mark the proximal part, 10 cm proximal to the elbow point along the line between the elbow and bicipital groove.
      2. Mark the distal part, 10 cm distal to the elbow point along the line between the elbow and wrist.
3. Measure the thickness of the subcutaneous tissue and muscle of the upper limb. The procedure should be performed by a skilled sonographer.
   1. Switch on the ultrasound system. Enter 2D mode of soft tissue via the keyboard. Set the depth to 5 cm.
      1. Choose the 14L5 linear array transducer.
      2. Apply sufficient gel to the ultrasound transducer. Focus on the subcutaneous tissue.
   2. Place the ultrasound transducer perpendicularly to the upper limb ventral axis. Use the short-axis view. Capture the image where the thickness of the gel is at least 1 cm and the soft tissue contour is not distorted.
   3. Measure the thicknesses of the muscle and subcutaneous tissue.
      1. Draws a line by selecting the calibrator in the software via the keyboard of the ultrasound system
      2. Measure the thickness of the muscle, defined as the distance from the highest point on the boundary of the bone to the highest point on the boundary portion of the fascia (Figure 2).
      3. Measure the thickness of the subcutaneous tissue, defined as the distance from the skin to the fascia.

2. Clinical Application of Ultrasonography to BCRL

1. Measure the thickness of the subcutaneous tissue and muscle of the upper limb at baseline.
   1. Perform the baseline measurements in the order shown in Step 1.
2. Instruct the patient to perform a series of PREs using a 0.5 kg dumbbell¹⁴.
   1. Give the patient a compression stocking or a multilayer bandage to wear. Choose a 0.5 kg dumbbell.
   2. Instruct the patient to perform the PREs in the following order: (1) dumbbell fly, (2) triceps extension, (3) one arm bent-over row, (4) biceps curl, (5) dumbbell side raise, and (6) lifting the arms forward (Figure 3).
      1. Instruct the patient to complete the 6 exercises twice a day, according to the following schedule: 5 times each during the 1^st week, 10 times each during the 2^nd week, 15 times each during the 3^rd week, 20 times each during the 4^th week, and 25 times each during 5^th-8^th weeks (Figure 4).
3. Use ultrasonography to identify the therapeutic effects of PRE compared to conventional therapy.
   1. Measure the thickness of the subcutaneous tissue and muscle of the upper limb at 4 and 8 weeks. Perform the measurements in the order shown in Step 1.
4. Calculate the thickness of the subcutaneous tissue and muscle at baseline, 4 weeks, and 8 weeks.
5. Analyze the data.
   1. Compare the difference between both arms using a paired t-test. Compare the changes in subcutaneous tissue and muscle thickness using a repeated-measures ANOVA.

Results

This study included 32 patients diagnosed with BCRL. The thickness of muscle and subcutaneous tissue and the circumferences of proximal and distal upper limbs were measured at baseline, 4 weeks, and 8 weeks after PRE. Examiners measured the circumference of upper limbs with a tape measure, and then the thickness of the muscle and subcutaneous tissue were measured by ultrasonography. Patients were randomly divided into a PRE group and a non-PRE group. Participants were reminded to not reve...

Discussion

Evaluations of BCRL can be conducted through various techniques, including arm circumferences tape measurement, water displacement measurement, bioimpedance spectroscopy, perometry (optoelectronic volumeter), lymphoscintigraphy, clinician diagnosis, or swelling self-reports by the patient. However, there are no standards for the measurement of BCRL; the diagnosis and duration of treatment can be determined empirically in a number of ways, depending upon the clinic.

Clinically, measuring arm ci...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
ACUSON S2000	Siemens	10041461
Eco Gel 99	Seung Won Medical Corp.