[Intraoperative photodynamic diagnosis for spinal ependymoma using 5-aminolevulinic acid: technical note].
OBJECTIVE
The fluorescence-guided resection using 5-aminolevulinic acid (5-ALA) is a well established method for the treatment of brain tumor, especially malignant glioma. However, there is no report on photodynamic diagnosis (PDD) for spinal tumor. In the present study, we evaluated the usefulness of PDD for spinal ependymoma using 5-ALA.


METHODS
Three patients with spinal ependymoma received oral doses of 5-ALA (20 mg/kg body weight) 2 hours before anesthesia induction. Intraoperatively, fluorescence was observed with a 420 nm sharp cut filter after excitation with a violet semiconductor laser (405 nm) and was verified by analysis of fluorescent spectra. Residual fluorescent samples taken from the tumor cavity were examined histologically


RESULTS
Fluorescence peaked at 636nm in the removed tumors in all cases. Fluorescent tissue tended to exist at the cranial and caudal portion in the tumor cavity or around the anterior median fissure. The residual fluorescent tissue was not detected after removal of the tumor in case 1. The residual fluorescent tissue was composed of tumor cells and ependymal lining in case 2 or the infiltrated inflammatory cells and vascular endothelial cells in case 3. Postoperative magnetic resonance (MR) imaging showed no residual tumor in any of the cases.


CONCLUSIONS
The results of this study indicate the usefulness of 5-ALA-induced tumor fluorescence in guiding resection of spinal ependymoma. 5-ALA-induced porphyrin fluorescence may label spinal ependymomas easily and clearly enough to enhance the completeness of tumor removal.
Arai
Takao
T
Department of Neurosurgery, Jikei University School of Medicine, 3-26-8 Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan. takao-a@jikei.ac.jp
Tani
Satoshi
S
Isoshima
Akira
A
Nagashima
Hiroyasu
H
Joki
Tatsuhiro
T
Takahashi-Fujigasaki
Junko
J
Abe
Toshiaki
T
D000328:Adult; D000622:Aminolevulinic Acid; D004806:Ependymoma / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D005453:Fluorescence; D006801:Humans; D007432:Intraoperative Period; D008029:Lighting; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017319:Photosensitizing Agents; D011166:Porphyrins; D012680:Sensitivity and Specificity; D013120:Spinal Cord Neoplasms / Q000175:diagnosis* / Q000601:surgery
D017319:Photosensitizing Agents; D011166:Porphyrins; D000622:Aminolevulinic Acid