Optimal surgical margin for infiltrative soft tissue sarcomas: Assessing the efficacy of excising beyond the infiltration

BACKGROUND: Tumor infiltration in soft tissue sarcoma (STS) is known to correlate with an inadequate surgical margin and poor local control. This study aims to determine whether the radiological infiltration (R-inf) in STS cor relates with histological infiltration (H-inf) and to devise methods to determine a resection margin for infiltrative STS. METHODS: We reviewed the medical records of 145 patients with high-grade STS. We measured the R-inf on short-T1 inversion recovery or gadolinium-enhanced fat-suppressed (GdFS) magnetic resonance imaging. In addition, we assessed H-inf as the infiltrative growth of atypical tumor cells. The local control rate (LCR) was assessed using the Kaplan-Meier method. RESULTS: A statistically significant positive correlation was found between H-inf and R-inf (P < 0.0001). The R-inf obtained from the GdFS images exhibited a stronger correlation with H-inf than that obtained from the short-T1 inversion recovery images. Univariate and multivariate analyses revealed that a positive H-inf significantly correlated with a poor LCR. Moreover, the contaminated margins, which included intrainfiltration margins, significantly correlated with a poor LCR compared with the wide margins. CONCLUSIONS: R-inf as assessed by the GdFS images significantly correlates with H-inf, suggesting that we should exercise the infiltrative STS beyond their R-infs detected by the GdFS images.