Evaluation of magnetic resonance imaging parameters and compliance with guidelines in soft tissue sarcomas

Accurate imaging plays a crucial role for prognostic assessment and treatment allocation in soft tissue sarcoma (STS). Guidelines recommend contrast-enhanced magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) for tumor assessment. This study aims to evaluate the extent to which the MRI protocols used in clinical practice align with the sequences specified in the guideline in the diagnostic work-up of sarcoma patients. We analyzed a cohort of patients treated at the Sarcoma Center of the University Medical Center Mannheim (UMM). Pretherapeutic MRI protocols were compared with the recommendations of the German sarcoma guideline. We analyzed 64 MRI examinations of patients with STS of the extremities and trunk, notably 62 performed at external radiology centers and 2 at UMM. A pretherapeutic contrast-enhanced MRI was available in 51 of 64 cases (79.7%), of which 40 referrals explicitly indicated a soft tissue tumor. In 3.1% of the cases, the complete set of guideline-recommended sequences was not performed. At least two of the required sequences were consistently available. The most frequently absent sequences were the T1-weighted sequence without fat saturation acquired before and after contrast administration using identical acquisition parameters (82.8%) and DWI sequences (78.1%). MRI protocol selection is primarily guided by the clinical referral question. Our analysis indicates that a substantial proportion of examinations deviated from recommended protocols. Contributing factors may include inaccurate clinical referral questions, limited guideline awareness, reimbursement constraints in outpatient settings, or diagnostic considerations. Standardized imaging represents a key instrument for quality assurance in the diagnosis of STS and forms the foundation for clinical and translational studies. In the future, the recommendations should be re-evaluated and published in a clear, accessible format to ensure broad implementation.