Transient Enlargement in Meningiomas Treated with Stereotactic Radiotherapy

Maksoud Z, Schmidt M, Huang Y, Rutzner S, Mansoorian S, Weissmann T, Bert C, Distel L, Semrau S, Lettmaier S, Eyüpoglu IY, Fietkau R, Putz F (2022)

Publication Language: English

Publication Type: Journal article, Original article

Publication year: 2022


Book Volume: 14

Pages Range: 1-13

Article Number: 1547

Journal Issue: Special Issue State-of-the-Art Research in Meningioma


DOI: 10.3390/cancers14061547

Open Access Link:


To investigate the occurrence of pseudoprogression/transient enlargement in meningiomas after stereotactic radiotherapy (RT) and to evaluate recently proposed volumetric RANO meningioma criteria for response assessment in the context of RT. Sixty-nine meningiomas (benign: 90%, atypical: 10%) received stereotactic RT from January 2005–May 2018. A total of 468 MRI studies were segmented longitudinally during a median follow-up of 42.3 months. Best response and local control were evaluated according to recently proposed volumetric RANO criteria. Transient enlargement was defined as volumetric increase ≥20% followed by a subsequent regression ≥20%. The mean best volumetric response was −23% change from baseline (range, −86% to +19%). According to RANO, the best volumetric response was SD in 81% (56/69), MR in 13% (9/69) and PR in 6% (4/69). Transient enlargement occurred in only 6% (4/69) post RT but would have represented 60% (3/5) of cases with progressive disease if not accounted for. Transient enlargement was characterized by a mean maximum volumetric increase of +181% (range, +24% to +389 %) with all cases occurring in the first year post-RT (range, 4.1–10.3 months). Transient enlargement was significantly more frequent with SRS or hypofractionation than with conventional fractionation (25% vs. 2%, p = 0.015). Five-year volumetric control was 97.8% if transient enlargement was recognized but 92.9% if not accounted for. Transient enlargement/pseudoprogression in the first year following SRS and hypofractionated RT represents an important differential diagnosis, especially because of the high volumetric control achieved with stereotactic RT. Meningioma enlargement during subsequent post-RT follow-up and after conventional fractionation should raise suspicion for tumor progression.

Authors with CRIS profile

How to cite


Maksoud, Z., Schmidt, M., Huang, Y., Rutzner, S., Mansoorian, S., Weissmann, T.,... Putz, F. (2022). Transient Enlargement in Meningiomas Treated with Stereotactic Radiotherapy. Cancers, 14(Special Issue State-of-the-Art Research in Meningioma), 1-13.


Maksoud, Ziad, et al. "Transient Enlargement in Meningiomas Treated with Stereotactic Radiotherapy." Cancers 14.Special Issue State-of-the-Art Research in Meningioma (2022): 1-13.

BibTeX: Download