|
|
Malignant
gliomas: MR imaging spectrum of radiation therapy- and chemotherapy-induced
necrosis of the brain after treatment
Kumar AJ, Leeds NE, Fuller GN, Van Tassel P, Maor MH, Sawaya RE, Levin VA
Division of Diagnostic Imaging, University of Texas M.D. Anderson
Cancer Center, Box 57, Houston, TX 77030, USA.
akumar@mdanderson.org
Purpose. To describe both the common and less frequently encountered
magnetic resonance (MR) imaging features of radiation therapy- and
chemotherapy-induced brain injury, with particular emphasis on radiation
necrosis.
Materials
and Methods. A
cohort of 148 adult patients underwent surgical resection of malignant brain
(glial) tumors and were subsequently entered into a research protocol that
consisted of accelerated radiation therapy with carboplatin followed by
chemotherapy with procarbazine, lomustine, and vincristine.
Patients typically underwent sequential MR imaging at 6-8-week intervals during
the 1st year and at 3-6-month intervals during subsequent years.
In all patients, histopathologic confirmation of lesion composition was
performed by board-certified neuropathologists.
Results.
The patients exhibited different types of MR imaging-detected abnormalities of
the brain: pure radiation necrosis in 20 patients, a mixture of predominantly
radiation necrosis with limited recurrent and/or residual tumor (less than 20%
of resected tissue) in 16 patients, radiation necrosis of the cranial nerves
and/or their pathways in two patients, radiation-induced enhancement of the
white matter in 52 patients, and radiation-induced enhancement of the cortex in
nine patients.
Conclusion.
The frequent diagnostic dilemma of recurrent neoplasm versus radiation necrosis
is addressed in this study through a description of the varying spatial and
temporal patterns of radiation necrosis at MR imaging.
PMID: 11058631 [PubMed - indexed for MEDLINE]
|
