Spatial and Temporal Variability of Upper Extremity Edema Measures After Breast Cancer Surgery
Linda A. Koehler, PhD, PT,1,2 and Harvey N. Mayrovitz, PhD3,4. Lymphatic Research Biology 2018
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Spatial and Temporal Variability of Upper Extremity Edema Measures After Breast Cancer Surgery
Linda A. Koehler, PhD, PT,1,2 and Harvey N. Mayrovitz, PhD3,4. Lymphatic Research Biology 2018
Background: Tissue dielectric constant (TDC), as an index of local tissue water, and girth measurements are quantitative methods to measure and characterize lymphedema. Objective: To describe the spatial and temporal variability in arm girth and TDC values in women surgically treated for breast cancer and to describe the relationship between these measures.
Methods and Results: This was a prospective longitudinal study that observed 36 women for 78 weeks after breast cancer surgery with lymph node removal. Arm circumferences and TDC values, as indices of local tissue water, were measured on both arms at multiple sites at postsurgery weeks 2, 4, 12, and 78 in women undergoing surgical breast cancer treatment with one or more axillary lymph nodes removed. TDC and girth values remained relatively uniform from visit-to-visit for both at-risk and contralateral control arms with no overall statistically significant difference in values (p>0.05). There was a strong inverse correlation between arm girth and the TDC value in both the at-risk and control arms (p<0.001). Overall, there was no statistically significant difference in TDC interarm ratios among visits or anatomical sites. TDC values for at-risk and control arms tended to significantly decrease with increasing distance from the wrist (p<0.001).
Conclusion: TDC arm values and girth measures remained relatively uniform in women after breast cancer surgery. The fact that TDC values are higher distally than proximally provides new information from which TDC measurements may be interpreted and also provides a better understanding of arm spatial variability in relation to girth measures.
Main findings
- The two main goals of this work are 1) to describe the spatial and temporal variability in TDC values in women treated for breast cancer at sequential times after their breast surgery, and 2) to describe the relationship of these TDC values with other assessment parameters, the patient’s breast cancer treatment, and treatment-related complications.
- Lymphedema measures were taken with individuals lying supine with the palm facing upward and arm slightly abducted to access the medial arm. Girth measurements were taken first followed by TDC measures. Marks were made with a marking pen on the medial side of the arms bilaterally from 0 to 40cm measuring at 8cm increments distal to proximal starting at the ulnar styloid.
- At each arm site, the TDC values remained relatively uniform from visit-to-visit for both at-risk and contralateral control arms with no overall statistically significant difference in TDC values among visits 1 through 4.
- There was a decrease in TDC values with increasing distance from the wrist, interarm TDC ratios remained relatively uniform with no overall significant difference among sites.
- Average interarm ratio for the six measured sites ranged from 1.003–0.070 at the wrist to 1.031–0.054 at 16cm proximal to the wrist. However, analysis of individual patient changes from visit-to-visit indicated that at 78 weeks postsurgery (visit 4), four patients showed interarm ratios >1.26, a value that has been reported to be indicative of lymphedema presence.
- The observed decrease in arm TDC values distal to proximal is likely influenced by the variation in tissue components with increased girth being associated with increased subcutaneous fat that has lower water content. Higher distal TDC values could also potentially be influenced by pooling of fluid in the distal arm due to the dependent position of the arm. Theoretically, one would expect fluid content to be higher in the distal arm and hand, especially if the arm is in a dependent position over the course of a day, but this was unlikely since the TDC measures were taken 8–10 minutes after the individual was positioned supine allowing for redistribution of fluid.
- A limitation is that preoperative measurements were not taken.
