Accuracy of magnetic resonance spectroscopy in distinction between radiation necrosis and recurrence of brain tumors.
Anbarloui، Mousa Reza نويسنده Department of Neurosurgery, School of Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Anbarloui, Mousa Reza , Ghodsi، Seyed Mohammad نويسنده Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran Ghodsi, Seyed Mohammad , Khoshnevisan، Alireza نويسنده Department of Neurosurgery, Shariati Hospital, Tehran University of Medical Sciences, Tehran, IR Iran , , Khadivi، Masoud نويسنده Department of Neurosurgery, School of Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Khadivi, Masoud , ABDOLLAHZADEH، SINA نويسنده , , Aoude، Ahmad نويسنده Department of Neurosurgery, School of Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Aoude, Ahmad , Naderi، Soheil نويسنده Department of Neurosurgery, School of Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Naderi, Soheil , Najafi، Zeynab نويسنده Department of Pediatrics, School of Medicine AND Childrens Medical Center, Tehran University of Medical Sciences, Tehran, Iran. Najafi, Zeynab , Faghih-Jouibari، Morteza نويسنده Department of Neurosurgery, School of Medicine, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran. Faghih-Jouibari, Morteza
Background: Distinction between radiation necrosis and recurrence of intraparenchymal tumors is necessary to select the appropriate treatment, but it is often difficult based on imaging features alone. We developed an algorithm for analyzing magnetic resonance spectroscopy (MRS) findings and studied its accuracy in differentiation between radiation necrosis and tumor recurrence.
Methods: Thirty-three patients with a history of intraparenchymal brain tumor resection and radiotherapy, which had developed new enhancing lesion were evaluated by MRS and subsequently underwent reoperation. Lesions with Choline (Cho)/N- acetyl aspartate (NAA) > 1.8 or Cho/Lipid > 1 were considered as tumor recurrence and the remaining as radiation necrosis. Finally, pre-perative MRS diagnoses were compared with histopathological report.
Results: The histological diagnosis was recurrence in 25 patients and necrosis in 8 patients. Mean Cho/NAA in recurrent tumors was 2.72, but it was 1.46 in radiation necrosis (P < 0.01). Furthermore, Cho/Lipid was significantly higher in recurrent tumors (P < 0.01) with the mean of 2.78 in recurrent tumors and 0.6 in radiation necrosis. Sensitivity, specificity, and diagnostic accuracy of the algorithm for detecting tumor recurrence were 84%, 75% and 81%, respectively.
Conclusion: MRS is a safe and informative tool for differentiating between tumor recurrence and radiation necrosis.