Evaluation of brain edema formation defined by MRI after LINAC-based stereotactic radiosurgery
Article Category: Research Articles
Published Online: Apr 12, 2017
Page range: 137 - 141
Received: Aug 28, 2016
Accepted: Mar 02, 2017
DOI: https://doi.org/10.1515/raon-2017-0018
© 2017 Maciej Harat, Andrzej Lebioda, Judyta Lasota, Roman Makarewicz
This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background
Peri-lesional edema is a serious and well-known complication of stereotactic radiosurgery (SRS). Here we evaluated edema risk after SRS and assessed its formation and resolution dynamics.
Patients and methods
107 patients underwent SRS for heterogeneous diagnoses: 34 (29%) with arteriovenous malformations, 38 (35%) with meningiomas, 16 (15%) with metastatic tumors, 16 (15%) with acoustic neuromas, 3 with (3%) cavernomas, and 2 (2%) each with anaplastic astrocytomas and anaplastic oligoastrocytomas. Edema area was delineated in MRI T2-FLAIR sequences 0, 6, 12, 18, 24, 30, and 38 months after treatment. Lesion location was defined as either above (n = 80) or below (n = 32) the “Frankfurt modified line” (FML).
Results
17% of patients developed or had worsening post-treatment edema. Edema volume was maximal at 6 months (mean 7.2, SD 1.2) post radiosurgery. Post-SRS edema was 5.1 (1.06 – 24.53) times more likely in patients with lesions above the FML. There was no association between edema development and age, PTV size, number of beams, and diagnosis (p = 0.07).
Conclusions
Radiosurgery-associated edema develops within 6 months of treatment and decreases over time. Edema occurrence is strongly related to lesion location, and its presence is much more likely when the treated lesions are situated above the Frankfurt line.