title: Radionecrosis secondary to interstitial brachytherapy: correlation of magnetic resonance imaging and histopathology.
abstract: Radiation-induced tissue damage in the central nervous system is a well-known complication of interstitial brachytherapy for brain tumors, yet imaging correlates have historically been based upon computed tomographic scans. We now present magnetic resonance imaging (MRI) to correlate radiation changes after interstitial brachytherapy with the histopathology. The central nervous system of a 38-year-old man with a left frontal cerebral glioma diagnosed by stereotactic biopsy was treated with interstitial brachytherapy (iridium-192, 47 Gy), followed by limited-field irradiation (45 Gy). With progressive deterioration, a second biopsy demonstrated radiation changes. Despite aggressive medical management, the patient died 9 months after completion of radiation therapy. Postmortem evaluation compared MRI scans of the intact, fixed brain with the histopathology. Axial sections (10 mm) obtained by MRI scan and autopsy brain slices were cut in the identical plane. Neuroimaging and histopathological findings of the lesion correlated within 2 to 3 mm resolution. In the peripheral white matter, MRI scan did not indicate the extent of radiation effect histologically. We suggest that MRI has limited utility in assessing the extent of impact of radiation on surrounding brain.
authors.affiliation: Department of Neurological Surgery, University of Southern California Medical Center, Los Angeles.
authors.forename: J H
authors.initials: JH
authors.lastname: Oppenheimer
authors.forename: M L
authors.initials: ML
authors.lastname: Levy
authors.forename: U
authors.initials: U
authors.lastname: Sinha
authors.forename: H
authors.initials: H
authors.lastname: el-Kadi
authors.forename: M L
authors.initials: ML
authors.lastname: Apuzzo
authors.forename: G
authors.initials: G
authors.lastname: Luxton
authors.forename: Z
authors.initials: Z
authors.lastname: Petrovich
authors.forename: C S
authors.initials: CS
authors.lastname: Zee
authors.forename: C A
authors.initials: CA
authors.lastname: Miller
mesh_terms: D000328:Adult; D001254:Astrocytoma / Q000473:pathology / Q000532:radiotherapy*; D001918:Brachytherapy; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D016371:Cranial Irradiation; D005625:Frontal Lobe / Q000473:pathology / Q000528:radiation effects*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009336:Necrosis; D011832:Radiation Injuries / Q000473:pathology*; D011879:Radiotherapy Dosage; D014057:Tomography, X-Ray Computed