title: Evaluation of serial changes on computed tomography and magnetic resonance imaging after implantation of carmustine wafers in patients with malignant gliomas for differential diagnosis of tumor recurrence.
abstract: Carmustine wafers are approved for localized treatment of malignant glioma. In this study, overall changes in computed tomography (CT) and magnetic resonance (MR) images of malignant glioma patients treated with carmustine wafer implantation were evaluated. The subjects were 25 patients undergoing craniotomy for malignant glioma resection and carmustine wafer implantation. Changes in the appearance of wafers, the resection cavity, and the adjacent parenchyma on CT and MR imaging were evaluated retrospectively. On CT, the wafers changed from an initially high-dense to an iso-dense appearance. All MR studies showed a low-intense wafer within 2 days. The wafers changed to a high- or iso-intense appearance on fluid attenuated inversion recovery and T1-weighted imaging, whereas they changed to an iso- to low-intense appearance on T2-weighted imaging. Gas in the cavity increased gradually after surgery, achieved a peak at 1 week postoperatively, and then disappeared in 1-3 months. Increased volume of the resection cavity was observed in 48% of patients. Regarding changes in the adjacent parenchyma, obvious contrast enhancement at the wall of the resection cavity was seen in 91% of cases at 1 month, but this disappeared gradually. Edema around the resection cavity was increased in 7 patients (28%), of whom only two experienced symptoms due to edema. We conclude that these radiological changes after carmustine wafer implantation should be carefully followed up, because these changes can easily be mistaken for infectious disease or recurrent tumors.
authors.affiliation: Departments of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan. sohue@m.ehime-u.ac.jp.
authors.forename: Shiro
authors.initials: S
authors.lastname: Ohue
authors.affiliation: Departments of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Kohno
authors.affiliation: Departments of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Inoue
authors.affiliation: Departments of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamashita
authors.affiliation: Departments of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Suehiro
authors.affiliation: Departments of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Toshimoto
authors.initials: T
authors.lastname: Seno
authors.affiliation: Departments of Regeneration of Community Medicine, Ehime University Graduate School of Medicine, Toon, Ehime, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kumon
authors.affiliation: Departments of Radiology, Ehime University Graduate School of Medicine, Toon, Ehime, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: Departments of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Ohnishi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002330:Carmustine / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D015918:Infusion Pumps, Implantable; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018906:Antineoplastic Agents, Alkylating; D002330:Carmustine
keywords: Carmustine wafer; Computed tomography; Gliadel; Magnetic resonance imaging; Malignant glioma