Perometry versus simulated circumferential tape measurement for the detection of breast cancer-related lymphedema

Fangdi Sun, Alexander Hall, Megan P, Tighe, Cheryl L. Brunelle, Hoda E. Sayegh, Tessa C. Gillespie, Kayla M. Daniell, Alphonse G. Taghian. Breast Cancer Research and Treatment 2018

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Perometry versus simulated circumferential tape measurement for the detection of breast cancer-related lymphedema

Fangdi Sun, Alexander Hall, Megan P, Tighe, Cheryl L. Brunelle, Hoda E. Sayegh, Tessa C. Gillespie, Kayla M. Daniell, Alphonse G. Taghian. Breast Cancer Research and Treatment 2018

Purpose Despite increasing emphasis on screening and early intervention for breast cancer-related lymphedema (BCRL), there is marked heterogeneity in diagnostic methodology, including for volumetric measures. This retrospective study compared two volumetric modalities, perometry and simulated circumferential tape measurement (anatomic- and interval-based), for BCRL detection.

Methods Between 2005 and 2017, 287 female patients with unilateral breast cancer were prospectively screened for BCRL by perometry and the relative volume change (RVC) formula. Circumferential measurement was performed by sampling at five anatomic landmark-based points or 4-cm intervals from pairs of perometer arm diameter measurements. Volumetric conversion was by a frustum model. The Bland–Altman method was used to compare segmental volume differences. Confusion matrix analysis was performed for each circumferential measurement technique against perometry.

Results Median follow-up was 34.7 months over 4 postoperative visits. There was no difference in total arm volume comparing any of the circumferential measurement techniques to perometry. Landmark-based methods significantly underestimated upper arm volume (mean difference − 207 mL [− 336, − 78 mL]) and overestimated forearm volume (mean difference + 170 mL [+ 105, + 237 mL]). Landmark-based methods had greater sensitivity and specificity compared to 4-cm interval methods for detection of both RVC ≥ 10 and 5–10%. Landmark-based methods were comparable to perometry for detection of RVC ≥ 10%, but sensitivity was only 63.2–66.7% for RVC 5–10%.

Conclusions This hypothesis-generating study suggested the superiority of anatomic landmark-based circumferential tape measurement compared to interval-based methods, while generating questions about the underestimation of upper arm volume and overestimation of forearm volume of circumferential tape measurement compared to perometry.

Main findings

  • N = 287
  • Unclear of the exact procedure of tape measuring.
  • Each of the four simulated circumferential measurement methods (4-cm intervals; 4-cm intervals, end correction; Landmarks; Landmarks, midpoint) was evaluated against perometry as an objective screening test for BCRL.
  • There was no significant difference between total arm volumes of either the ipsilateral or contralateral side, this study showed that anatomic landmark-based methods underestimate volume of the upper arm and overestimate volume of the forearm. The absolute magnitude of this mean difference was greater than 200 mL for both the ipsilateral and contralateral upper arm.
  • Only one quarter had oedema distributed throughout the whole arm. This finding raises concerns about detection of localized lymphedema with landmark-based circumferential methods, given systematic upper arm underestimation.
  • Landmark-based methods performed well for detection of relative volume change (RVC) ≥ 10%, its sensitivity was only 63.2–66.7% for RVC 5–10%.
  • The simulated nature of circumferential measurement in this study does not allow us to account for test–retest reliability and the human error of tape measurement.
  • This study suggested the superiority of landmark-based simulated circumferential measurement compared to interval-based techniques, a finding that has the potential to minimize the time providers spend measuring patients. At the same time, these findings generated questions about the underestimation of upper arm volume and overestimation of forearm volume compared to perometry, a significant finding for emerging concerns of segmental lymphedema both demonstrated here and in previous work. These questions warrant further research, specifically in the form of prospective screening trials that directly compare techniques of volumetric BCRL quantification.