MRI-Based Delta Necrosis as a Prognostic Marker Following Neoadjuvant Chemotherapy in Soft Tissue Sarcoma.

Area of Science:

• Oncology
• Radiology
• Pathology

Background:

• The prognostic significance of treatment-induced necrosis in soft tissue sarcoma (STS) is not well-established.
• Assessing therapeutic response in STS often relies on imaging, but the reliability of necrosis changes is uncertain.

Purpose of the Study:

• To investigate the correlation between MRI-based changes in necrosis (Δ necrosis) and pathologic necrosis in STS patients post-neoadjuvant chemotherapy.
• To determine if MRI-derived necrosis predicts clinical outcomes, including progression-free and overall survival.

Main Methods:

• Retrospective analysis of 27 STS patients who received neoadjuvant chemotherapy and underwent pre- and post-treatment MRI.
• Categorical grading of necrosis on MRI and calculation of Δ necrosis; correlation with pathologic necrosis using Spearman's rank coefficient.
• Survival analyses (progression-free, local recurrence-free, disease-specific overall survival) using Kaplan-Meier and log-rank tests.

Main Results:

• Post-treatment MRI necrosis showed a moderate correlation with pathologic necrosis (ρ = 0.44, p = 0.028).
• Δ necrosis demonstrated a weaker, nonsignificant correlation with pathologic necrosis (ρ = 0.24, p = 0.24).
• Neither MRI-based nor pathologic necrosis thresholds were significantly associated with patient survival outcomes.

Conclusions:

• MRI-based Δ necrosis is not a reliable predictor of pathologic necrosis or oncologic outcomes in STS.
• Radiologic changes in necrosis may not accurately reflect therapeutic response in STS.
• Future research should integrate quantitative imaging, standardized pathology, and molecular tools like ctDNA for improved treatment assessment.