Linear mixed-effects models for predicting sarcoma local recurrence growth rates: Implications for optimal
Catherine S King1, Ronnie Sebro2
1Department of Radiology, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, United States.
European Journal of Radiology
|October 3, 2020
Summary
Patients with positive surgical margins had faster-growing sarcomas (LRs). For these patients, contrast-enhanced MRI surveillance every 6 months is recommended to detect local recurrence (LR) growth.
Area of Science:
- Oncology
- Radiology
- Surgical Pathology
Background:
- Sarcomas, rare mesenchymal tumors, often require surgical resection and radiation to prevent local recurrence (LR).
- Contrast-enhanced MRI is standard for LR surveillance, but optimal imaging frequency remains undetermined.
- Understanding LR growth dynamics is crucial for refining surveillance protocols.
Purpose of the Study:
- To calculate sarcoma local recurrence (LR) growth rates.
- To identify factors influencing LR growth.
- To predict optimal imaging surveillance frequency for sarcoma LRs.
Main Methods:
- Retrospective cohort study of 34 sarcoma patients with 60 histologically confirmed LRs (2007-2020).
- Maximum LR length measured on surveillance MRI.
- Linear mixed-effects models analyzed LR growth rate and influencing factors (age, sex, tumor grade, margins, adjuvant therapy).
Main Results:
- Microscopically positive margins were significantly associated with faster LR growth (P=0.036).
- 90% of LRs occurred within 42.8 months post-surgery.
- Predicted optimal surveillance MRI frequency for positive margins: every 6.2 months to detect 1cm LRs.
Conclusions:
- Positive surgical margins predict more aggressive local recurrence (LR) growth in sarcomas.
- Conservative surveillance MRI every 6 months is suggested for patients with positive margins.
- This strategy aims to detect LRs when they are approximately 1cm in size.
