Semi-automated volumetric quantification of tumor necrosis in soft tissue sarcoma using contrast-enhanced MRI

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Current Response Evaluation Criteria in Solid Tumors (RECIST) have limitations in assessing soft tissue sarcoma (STS) treatment response.
• Histopathological assessment of necrosis post-resection is crucial for evaluating STS response.
• A novel semi-automated technique using contrast-enhanced magnetic resonance imaging (CE-MRI) for volumetric tumor necrosis measurement is introduced.

Purpose of the Study:

• To evaluate the accuracy and reproducibility of a semi-automated CE-MRI technique for measuring tumor necrosis in STS.
• To compare CE-MRI-based necrosis measurements with histopathological findings and RECIST criteria.

Main Methods:

• Eighteen patients with STS underwent neoadjuvant therapy followed by resection.
• Contrast-enhanced magnetic resonance imaging (CE-MRI) scans were acquired before resection.
• Two observers performed semi-automated segmentation on CE-MRI scans to determine tumor volume and percent necrosis.
• Measurements were compared with post-operative histopathology and RECIST criteria.

Main Results:

• Median percent necrosis by histology was 71.9%, and by CE-MRI was 67.8%.
• CE-MRI measurements showed statistical similarity to histopathological assessment, confirming accuracy.
• High intra-class correlation coefficients indicated good inter-observer reproducibility.
• Tumor necrosis measurements did not correlate with RECIST criteria.

Conclusions:

• Semi-automated determination of tumor volume and necrosis using CE-MRI is accurate.
• The CE-MRI technique demonstrates good reproducibility for assessing tumor necrosis in STS.
• This method offers a valuable alternative or adjunct to traditional assessment methods.