Clinical Report: Late Enhancement and Washout Maps in Malignant Brain Tumors

Overview

This retrospective, single-center observational study examined whether MRI late-enhancement and washout maps could help distinguish tumor progression from radiation necrosis in adults with malignant brain tumors. The supplied article excerpt describes the rationale, eligibility criteria, and imaging approach but does not provide the study’s sample size, diagnostic results, or conclusions.

Background

Contrast-enhanced T1-weighted MRI is central to response assessment in glioblastoma and informs the RANO criteria, but treatment-related changes such as radiation necrosis and pseudoprogression can resemble tumor progression. This overlap limits the specificity of conventional MRI and complicates post-treatment assessment. The article identifies perfusion MRI, MR spectroscopy, diffusion-weighted imaging, and PET as additional imaging approaches; it also notes that amino acid PET availability may be limited by infrastructure and radiotracer access. The study’s approach uses images acquired at different times after contrast administration to map washout and delayed enhancement.

Data Highlights

Key Findings

• The study was designed to assess whether delayed-enhancement imaging could improve differentiation of true progression from radiation necrosis during follow-up of malignant brain tumors.
• Eligible patients had newly appearing contrast-enhancing lesions on follow-up MRI after surgery and radiochemotherapy; suspected diagnoses included progression, radiation necrosis, or pseudoprogression.
• The protocol used two post-contrast T1-weighted acquisitions, with the first obtained approximately 5–9 minutes after contrast administration; the supplied excerpt does not specify the timing of the second acquisition.
• Washout maps were generated by co-registering and normalizing the image sets and subtracting corresponding voxels; red represented washout and green represented delayed or late enhancement.
• The excerpt provides no enrolled-patient count, reference-standard details, diagnostic accuracy estimates, or study outcome results.
• Related literature listed in the supplied context includes a 2010 study of parametric response maps for distinguishing progression from pseudoprogression in high-grade glioma and a 2008 study of functional diffusion maps as an early imaging biomarker; no results from those studies are provided here.

Clinical Implications

The supplied material describes late-enhancement and washout mapping as an investigational imaging approach and does not report results sufficient to establish its diagnostic performance or clinical role. It also notes that amino acid PET may assist when MRI findings are inconclusive, while access can depend on specialized infrastructure and radiotracer availability.

Conclusion

The article excerpt outlines a temporally resolved MRI method intended to distinguish tumor progression from radiation necrosis in malignant brain tumors. Because outcome data are not included in the supplied text, the method’s diagnostic performance cannot be summarized.

Related Resources & Content

1. Tsien C, et al., Journal of Clinical Oncology, 2010 -- Parametric Response Map As an Imaging Biomarker to Distinguish Progression From Pseudoprogression in High-Grade Glioma
2. Hamstra DA, et al., Neuro-Oncology, 2008 -- Functional Diffusion Map As an Early Imaging Biomarker for High-Grade Glioma: Correlation With Conventional Radiologic Response and Overall Survival
3. Wen PY, et al., Neuro-Oncology, 2023 -- RANO 2.0: Update to the Response Assessment in Neuro-Oncology Criteria for High- and Low-Grade Gliomas in Adults
4. EANM/EANO/RANO/SNMMI, European Journal of Nuclear Medicine and Molecular Imaging -- Joint practice guideline/procedure standard for PET imaging of brain metastases: version 1.0
5. Contrast clearance analysis in neuro-oncology: A systematic review and meta-analysis on differentiating posttreatment changes from tumor progression
6. ASCO Publications — Parametric Response Map As an Imaging Biomarker to Distinguish Progression From Pseudoprogression in High-Grade Glioma
7. Journal of Neuro-Oncology — Radiological and pathomic analyses of glioblastoma reveal non-enhancing tumor infiltration phenotypes linked to response to bevacizumab therapy
8. RANO 2.0: Update to the Response Assessment in Neuro-Oncology Criteria for High- and Low-Grade Gliomas in Adults
9. Joint EANM/EANO/RANO/SNMMI practice guideline/procedure standard for PET imaging of brain metastases: version 1.0
10. Contrast clearance analysis in neuro-oncology: A systematic review and meta-analysis on differentiating posttreatment changes from tumor progression
11. RANO 2.0: Update to the Response Assessment in Neuro-Oncology Criteria for High- and Low-Grade Gliomas in Adults - PMC
12. Joint EANM/EANO/RANO/SNMMI practice guideline/procedure standard for PET imaging of brain metastases: version 1.0 | European Journal of Nuclear Medicine and Molecular Imaging | Springer Nature Link
13. Contrast clearance analysis in neuro-oncology: A systematic review and meta-analysis on differentiating posttreatment changes from tumor progression - PMC
14. Dynamic susceptibility contrast perfusion in differentiation between recurrence and pseudoprogression in glioblastoma: a systematic review and meta-analysis - PMC
15. Diagnostic Accuracy of Amino Acid PET for Differentiating Tumor Recurrence or Progression from Treatment-Related Changes in Glioma Patients: A Systematic Review and Meta-Analysis