Challenges in Imaging Treated Brain Tumors
Yae Won Park1
1Yonsei University College of Medicine, Korea, Republic of

Synopsis

The accurate assessment of glioma disease status is challenging due to the complex combination of therapies and treatment-related changes, along with the sometimes ambiguous and overlapping imaging findings.

The history of response assessment in glioma – Macdonald, RANO, and mRANO – will be introduced and discussed. The posttreatment imaging findings, including pseudoprogression, radiation necrosis, pseudoresponse, and true progression, will be discussed.

In short, this lecture will endeavor to aid the real-world imaging interpretation situation, where us radiologists must make our own decision on the posttreatment glioma MRI with the accessible information, and give the clinicians a satisfying answer.

Outline

This talk will focus on the imaging finding of treated gliomas. The accurate assessment of glioma posttreatment imaging is challenging in clinical practice.

The history of response assessment in glioma – Macdonald, RANO, and mRANO – will be introduced and discussed. Limitations of the current response assessment criteria and recent AI researches which attempt to solve these limitations will be mentioned.

The posttreatment imaging findings, including pseudoprogression, radiation necrosis, pseudoresponse, and true progression, will be discussed. Apart from the well-known imaging findings in distinguishing treatment-related change from true progression, such as conventional imaging and advanced imaging (including DWI, DSC, DCE, and APT imaging), the importance of the clinical context, which is sometimes neglected by radiologists, will be emphasized. The glioma grade, molecular markers, extent of resection, imaging point, radiation field, treatment modality, and clinical symptoms are all crucial information that should be never missed out when interpreting the posttreatment imaging of gliomas; after literature review on the impact of these information in posttreatment imaging interpretation, examples will be shown in real cases. When discussing tumor progression, recent research results on leptomeningeal metastases, which is an underrecognized downstream result of glioma, will be also mentioned.

Acknowledgements

None

References

Cancer Genome Atlas Research Network. "Comprehensive, integrative genomic analysis of diffuse lower-grade gliomas." New England Journal of Medicine 372.26 (2015): 2481-2498.

Arber, Daniel A., et al. "The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia." Blood, The Journal of the American Society of Hematology 127.20 (2016): 2391-2405.

Louis, David N., et al. "The 2021 WHO classification of tumors of the central nervous system: a summary." Neuro-oncology 23.8 (2021): 1231-1251.

Lin, Nancy U., et al. "Response assessment criteria for brain metastases: proposal from the RANO group." The lancet oncology 16.6 (2015): e270-e278.

Ellingson, Benjamin M., Patrick Y. Wen, and Timothy F. Cloughesy. "Modified criteria for radiographic response assessment in glioblastoma clinical trials." Neurotherapeutics 14.2 (2017): 307-320.

Haider, Ali S., et al. "Toward a standard pathological and molecular characterization of recurrent glioma in adults: a Response Assessment in Neuro-Oncology effort." Neuro-oncology 22.4 (2020): 450-456.

Proc. Intl. Soc. Mag. Reson. Med. 30 (2022)