Intraoperative 5-aminolevulinic acid-induced photodynamic diagnosis of metastatic brain tumors with histopathological analysis

• Published in: World journal of surgical oncology 2017-09, Vol.15 (1), p.179-179, Article 179
• Main Authors: Yagi, R, Kawabata, S, Ikeda, N, Nonoguchi, N, Furuse, M, Katayama, Y, Kajimoto, Y, Kuroiwa, T
• Format: Article
• Language: English
• Subjects: 5-Aminolevulinic acid (5-ALA); Acids; Adjacent brain tissue; Adult; Aged; Aminolevulinic acid; Aminolevulinic Acid - administration & dosage; Aminolevulinic Acid - metabolism; Bone cancer; Brain; Brain - diagnostic imaging; Brain - pathology; Brain - surgery; Brain cancer; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - pathology; Brain Neoplasms - surgery; Brain tumors; Cancer; Cancer therapies; Care and treatment; Cell invasion; Chemotherapy; Diagnosis; Female; Fluorescence; Gliomas; Humans; Intraoperative Care - methods; Light; Magnetic Resonance Imaging; Male; Margins of Excision; Melanoma; Metastases; Metastasis; Metastatic brain tumor; Middle Aged; Navigation systems; Neoplasm Invasiveness - diagnostic imaging; Neoplasm Invasiveness - pathology; Neurosurgery; Neurosurgical Procedures - instrumentation; Neurosurgical Procedures - methods; Patients; Photodynamic diagnosis (PDD); Photosensitizing Agents - administration & dosage; Prostate cancer; Protoporphyrin; Protoporphyrin IX; Protoporphyrin IX (PpIX); Protoporphyrins - chemistry; Radiation therapy; Retrospective Studies; Studies; Surgery; Surgery, Computer-Assisted - instrumentation; Surgery, Computer-Assisted - methods; Tumors
• ISSN: 1477-7819; 1477-7819
• DOI: 10.1186/s12957-017-1239-8

Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) is a promising real-time navigation method in the surgical resection of malignant gliomas. In order to determine whether this method is applicable to metastatic brain tumors, we evaluated the usefulness of intraoperative fluorescence patterns and histopathological features in patients with metastatic brain tumors. We retrospectively reviewed the cases of 16 patients with metastatic brain tumors who underwent intraoperative 5-ALA fluorescence-guided resection. Patients were given 20 mg/kg of 5-ALA orally 2 h prior to the surgery. High-powered excitation illumination and a low-pass filter (420, 450, or 500 nm) were used to visualize the fluorescence of protoporphyrin IX (PpIX), the 5-ALA metabolite. We evaluated the relationships between the fluorescence and histopathological findings in both tumoral and peritumoral brain tissue. Tumoral PpIX fluorescence was seen in only 5 patients (31%); in the remaining 11 patients (69%), there was no fluorescence in the tumor bulk itself. In 14 patients (86%), vague fluorescence was seen in peritumoral brain tissue, at a thickness of 2-6 mm. The histopathological examination found cancer cell invasion of adjacent brain tissue in 75% of patients (12/16), at a mean ± SD depth of 1.4 ± 1.0 mm (range 0.2-3.4 mm) from the microscopic border of the tumor. There was a moderate correlation between vague fluorescence in adjacent brain tissue and the depth of cancer cell invasion (P = 0.004). Peritumoral fluorescence may be a good intraoperative indicator of tumor extent, preceding more complete microscopic gross total resection. Institutional Review Board of Osaka Medical College No. 42, registered February 17, 1998, and No. 300, registered April 1, 2008. They were retrospectively registered.