title: CT densitometry of the brain: a novel method for early detection and assessment of irradiation induced brain edema.
abstract: The purpose of the study was to examine if the CT densitometric analysis during radiotherapy (RT) of brain tumors is suitable for the early detection of RT induced brain edema (BE), predicting related neurological progress, and assessing the effects of different edema therapies. Planimetric CT-densitograms were constructed by modifying the "High-Lighting" method. Three theoretical density regions were defined and color-coded on the images of the brain. These were defined as edema (10-20 HU), mild edema, and normal brain (29-38 HU). Corresponding axial CT slices were created at the mid-level of the lesion and that of the periventricular white matter to verify the changes in perifocal and diffuse BE. The monitoring was performed on 50 solitary brain tumor patients treated with RT. During RT courses weekly CT-densitometric examinations were carried out. We experienced that changes in densitograms coincided with clinical symptoms, furthermore, preceded the latter. With the use of preventive edema medication based on diuretics and along with adjunctive edema medication adopted to densitograms, the 5-7 week irradiation was completed without ultimate worsening in performance state in 49 of 50 cases and besides we succeeded in avoiding the routine usage of steroids. Based on our findings the CT-densitometry is suitable for early detection and continuous assessment of BE and preventing patient distress during RT. This simple, reproducible and non-invasive procedure could provide an additional clinical tool for new treatment strategies.
authors.affiliation: National Institute of Oncology, Department of Radiotherapy, Budapest, H-1122 Hungary. mangel@oncol.hu
authors.forename: L
authors.initials: L
authors.lastname: Mangel
authors.forename: K
authors.initials: K
authors.lastname: Vönöczky
authors.forename: Z
authors.initials: Z
authors.lastname: Hanzély
authors.forename: T
authors.initials: T
authors.lastname: Kiss
authors.forename: P
authors.initials: P
authors.lastname: Agoston
authors.forename: A
authors.initials: A
authors.lastname: Somogyi
authors.forename: G
authors.initials: G
authors.lastname: Németh
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000528:radiation effects; D001929:Brain Edema / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000628:therapy; D001932:Brain Neoplasms / Q000150:complications / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011878:Radiotherapy / Q000009:adverse effects; D014057:Tomography, X-Ray Computed / Q000379:methods*