500 Section - Feasibility of a Mobile App–Based Self-Monitoring for Objective Volume Assessment in Breast Cancer related Lymphedema

Lymphedema is a chronic condition requiring lifelong self-management. Patients with breast cancer–related lymphedema (BCRL) often face difficulties due to limited physical function, time constraints, low self-efficacy, and insufficient or inconsistent information. Structured and scalable support, including objective assessment of swelling, is essential, yet reliable self-monitoring tools remain limited. This study evaluated the feasibility of a digital healthcare intervention—a mobile app combined with a smart tape measure—for self-monitoring among BCRL patients.

Design: Thirty participants completed this 3-month, single-arm, multicenter study. The intervention included a mobile self-management app and a smart tape measure enabling patients to track arm volume changes and receive self-care guidance. The smart tape measure was preliminarily evaluated and showed acceptable reliability and validity for clinical use. Participants were instructed to measure swelling at least weekly; researchers provided reminders or re-education when data were missing or inaccurate. Primary outcomes included app usability (System Usability Scale and a custom questionnaire), adherence (usage trends), and objective limb volume via Perometer.

Results:

Participants reported a high perceived need for a self-management app (mean=4.93±1.11). App usage averaged once per week throughout the study. Limb volume showed no significant change according to Perometer measurements. Usability was rated as good (SUS=71.25±9.84), with high scores (≥4.0) for satisfaction, usefulness, ease of use, behavioral intention, continued use, and willingness to recommend. Participants also reported positive perceived behavioral changes (mean≥4.0). However, some users noted the need for improvements in app and device quality (mean=3.5±1.05), particularly regarding inconvenience with the smart tape measure (mean=4.17±1.33).

Conclusion: Overall, this mobile app–based self-monitoring system appears feasible and acceptable for supporting self-care in BCRL. While engagement and usability outcomes were positive, device usability challenges highlight the need for refinement to reduce burden and improve long-term adherence. Ongoing data collection will further clarify clinical effectiveness and guide future enhancements.