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LymphActivist's Site
Dedicated to Lymphedema Patients and the Therapists Who Treat Them
LymphActivist's Site
Dedicated to Lymphedema Patients and the Therapists Who Treat Them
REVIEW – JOHANSSON (2014)
MEASUREMENT OF BREAST LYMPHEDEMA WITH TISSUE DIELECTRIC CONSTANT
This is a review of one of the more important papers to be published this year. The paper entitled "Breast edema following breast conserving surgery and radiotherapy" was published in the European Journal of Lymphology and Related Problems in 2014. Authors Karen Johansson was from the Institute of Health Science at Lund University in Sweden, Tapani Lathinen from the Cancer Center at Kuopio University Hospital in Finland, and Thomas Bjork-Eriksson from the Department of Oncology at Skäne University Hospital and Lund University in Sweden.
The paper is noteworthy in that it uses a new method of lymphedema measurement suitable to non-extremity body parts, and it explores the relative contributions of surgery and radiotherapy to the risk of lymphedema of the breast. An incidental outcome of the study is a comment on the relative effect of hypo-fractionated radiation on lymphedema risk.
Rates of lymphedema vary in the literature due predominantly to the lack of a standard means of measurement, standard criteria, and inability to measure lymphedema affecting body sites other than the arms or legs. Recent studies by Clarke and Rönkä within the last decade have disclosed that rates of lymphedema affecting the breast and trunk are equivalent to the rates affecting the arms of patients treated for breast cancer. Research in this area has been difficult because of the lack of an appropriate and accepted means of measurement of lymphedema of the breast and trunk.
Recently two measurement protocols have been documented that have been found to be useful and stable. One of these, used the by Rönkä, is the ultrasonic measurement of skin thickness, relying on the observation that lymphedema often presents as a thickening of the dermal layer due to presence of interstitial fluid. The 2nd method that has been found useful is the measurement of the amount of interstitial fluid by radiological measurements.
One instrument developed to make these measurements of interstitial fluid is the Moisture Meter D, developed by the Delfin company in Finland. This noninvasive measurement involves the imposition of radio frequencies into a small area of skin and measurement of the characteristics of the return signal. Appropriate selection of frequency and size of the probe limits the signal to the depths of 2.5 mm, corresponding to the effective area of the superficial lymph system. Extensive studies of the use of this technique for measuring lymphedema by measurement of the tissue dielectric constant (TDC) have been performed by Dr. Harvey Mayrovitz in Florida.
In this study 118 patients were measured prior to, during, and 2 and 4 weeks after the end of radiotherapy (RT). Measurements of TDC were made on each of the 4 quadrants of the affected breast and the non-affected breast. Measurement of localized lymphedema prior to and after surgery was able to yield information on the risk of lymphedema due to surgery, and measurements after surgery but before radiation and then after radiation were able to define additional risk of lymphedema due to radiation.
Results: Difference in TDC ratio (p < 0.001) between the operated and healthy breast was found at each measurement time-point. The incidence of breast edema was 31.4% before start of the RT treatment, increasing during RT and was 62.6% at 4 weeks after completion of RT. The mean pre-RT TDC ratio 1.30 ± 0.29 increased during the first week of therapy to 1.43 ± 0.33 and stayed elevated through the observation period (p < 0.001). Pre-RT patients with scar in quadrant 4 showed higher TDC ratio (p = 0.02) (n = 71, TDC ratio 1.36 ± 0.31) than patients with no scar tissue in quadrant 4 (n = 46, a TDC ratio 1.20 ± 0.23). [Paper Abstract]
Conclusion: The healthy breast can act as a control to provide a ratio between the breasts. Based on the evaluation of the mean TDC ratio, the incidence of breast edema was found to be high (> 30%). The TDC values illustrating edema in the operated breast were higher compared to the healthy breast at all measurement time-points, also pre-RT, suggesting a high influence of surgery on breast edema. However, axillary surgery did not seem to increase breast edema more than sentinel lymph node biopsy. It was also shown that patients with scar in the fourth quadrant are more likely to have a higher TDC ratio. The higher weekly doses in the hypofractionated RT seem to induce more edema than conventional fractionation. [Paper Abstract]
REFERENCES:
Clarke D, Martinez A, Cox RS, Goffinet DR: "Breast edema following staging axillary node dissection in patients with breast carcinoma treated by radical radiotherapy." Cancer Jun 1, 1982;49(11):2295-9.
Mayrovitz HN: "Assessing tissue edema in Postmastectomy lymphedema" Lymphology 2007;40:87-94.
Nuutinen J., Ikäheimo R., Lahtinen T.: "Validation of a new dielectric device to assess changes of tissue water in skin and subcutaneous fat" Physiol Meas. 2004; 25(2): 447-54.
Rönkä R.H., Pamilo MS, von Smitten KA, Leidenius MH: "Breast lymphedema after breast conserving treatment. Acta Oncol. 2004; 43: 551-7.