Appearance of recurrent adult fibrosarcoma of the soft tissue and loco-regional post-treatment changes on MRI follow-up

Inferring malignancy grade of soft tissue sarcomas from magnetic resonance imaging features: A systematic review

PURPOSE

Systematic reviews on the grading of STS using MRI are lacking. This review analyses the role of different MRI features in inferring the histological grade of STS.

MATERIALS AND METHODS

A systematic review was conducted and is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) checklist. The electronic databases of PubMed/MEDLINE were systematically searched for literature addressing the correlation of MRI findings in soft tissue sarcoma with tumor grade. As keywords "MRI", "magnetic resonance imaging", "sarcoma", "grade", "grading", and "FNCLCC" have been selected.

RESULTS

14 studies have been included in this systematic review. Tumor size (p = 0.015 (51 patients) to p = 0.81 (36 patients)), tumor margin (p < 0.001 (95 patients) to 0.93 (36 patients)), necrosis (p = 0.004 (50 patients) to p = 0.65 (95 patients)), peritumoral edema (p = 0.002 (130 patients) to p = 0.337 (40 patients)), contrast enhancement (p < 0.01 (50 patients) to 0.019 (51 patients)) and polycyclic/multilobulated tumor configuration (p = 0.008 (71 patients)) were significantly associated with STS malignancy grade in most of the included studies. Heterogeneity in T2w images (p = 0.003 (130 patients) to 0.202 (40 patients)), signal intensity in T1w images/ hemorrhage (p = 0.02 (130 patients) to 0.5 (31 patients)), peritumoral contrast enhancement (p < 0.001 (95 patients) to 0.253 (51 patients)) and tumoral diffusion restriction (p = 0.01 (51 patients) to 0.53 (52 patients)) were regarded as significantly associated with FNCLCC grade in some of the studies which investigated these features. Most other MRI features were not significant.

CONCLUSION

Several MRI features, such as tumor size, necrosis, peritumoral edema, peritumoral contrast enhancement, intratumoral contrast enhancement, and polycyclic/multilobulated tumor configuration may indicate the malignancy grade of STS. However, further studies are needed to gain consensus.

Does the primary soft-tissue sarcoma configuration predict configuration of recurrent tumors on magnetic resonance imaging?

BACKGROUND

Soft-tissue sarcomas (STS) are rare malignancies of the soft tissue.

PURPOSE

To assess whether the magnetic resonance imaging (MRI) configuration of primary STS can predict the configuration of a recurring tumor and whether the MRI configuration of multiple recurrences differs in one and the same patient.

MATERIAL AND METHODS

Thirty-nine patients with histologically proven recurrent STS were included in this retrospective study and underwent pre- and post-treatment MRI. Three main configurations of primary and recurrent tumors were identified: polycyclic/multilobulated; ovoid/nodular; and streaky.

RESULTS

Sixty recurrent lesions were detected: 34 ovoid/nodular; 15 polycyclic/multilobulated; and 11 streaky. Five recurrences were multifocal and eight were bifocal. Of 39 patients, 28 (71.8%) presented one recurrence within the MRI follow-up period (P = 0.006); in 10 patients (25.6%), up to three different configurations of recurring STS were identified in one patient. Recurrences of polycyclic/multilobulated primaries were mostly ovoid/nodular (48%; P = 0.003) or polycyclic/multilobulated (37%; P = 0.014), and recurring ovoid/nodular STS significantly most often showed the same configuration as the primary tumor (85%; P < 0.001). Primary STS with a streaky configuration recurred in all three configurations in roughly equal proportions. Homogeneity/heterogeneity and tumor borders are significantly associated with the configuration of recurrences.

CONCLUSION

Primary STS configuration may help predict recurrent tumor configuration when the primary STS had a polycyclic/multilobulated or ovoid/nodular configuration. However, recurrent STS configuration can also differ from primary STS configuration, especially when the primary STS had a streaky configuration, rendering recurrent STS difficult to predict. Different configurations of recurrent STS in one and the same patient are common.

Configuration of soft-tissue sarcoma on MRI correlates with grade of malignancy

Background

The aim of the study was to assess whether the configuration of primary soft-tissue sarcoma (STS) on MRI correlates with the grade of malignancy.

Patients and methods

71 patients with histologically proven STS were included. Primary STS were examined for configuration, borders, and volume on MRI. The tumors were divided into high-grade (G3), intermediate-grade (G2) and low-grade (G1) STS according to the grading system of the French Federation of Cancer Centers Sarcoma Group (FNCLCC).

Results

30 high-grade, 22 intermediate-grade and 19 low-grade primary STS lesions were identified. High- and intermediate-grade (G3/2) STS significantly most often appeared as polycyclic/multilobulated tumors (p < 0.001 and p = 0.002, respectively). Low-grade (G1) STS mainly showed an ovoid/nodular or streaky configuration (p = 0.008), and well-defined borders. The appearance of high-, intermediate- and low-grade STS with an ovoid/nodular configuration were mainly the same on MRI. All streaky G3/2 sarcoma and 17 of 20 patients with polycyclic/multilobulated G3 sarcoma showed infiltrative borders. High-grade streaky and polycyclic/multilobulated STS are larger in volume, compared to intermediate- and low-grade STS.

Conclusions

Configuration of STS on MRI can indicate the grade of malignancy. Higher-grade (G2/3) STS most often show a polycyclic/multilobulated configuration, while low-grade STS are mainly ovoid/nodular or streaky. Infiltrative behavior might suggest higher-grade STS in streaky and polycyclic/multilobulated STS.