366 Turk Neurosurg 30(3):366-370, 2020 Received: 11.02.2019 Accepted: 01.06.2019 Published Online: 03.12.2019 Muge AKMANSU 1 , Gokhan KURT 2 , Volkan DEMIRCAN 1 , Ertugrul SENTURK 1 1 Gazi University, School of Medicine, Department of Radiation Oncology, Ankara, Turkey 2 Gazi University, School of Medicine, Department of Neurosurgery, Ankara, Turkey This study has been presented at the 11 th Multidisciplinary Neurooncology Symposium between 24 and 27 May 2018 at Mugla, Turkey. Results of Chordoma Patients Treated by Different Approaches in a Single Institution ABSTRACT AIM: To discuss the optimal and recent treatment options based on clinical review of 16 chordoma patients. MATERIAL and METHODS: Data of the patients diagnosed and treated between 1999 and 2017 in Gazi University School of Medicine has been collected through patients’ fles and the electronic database of hospital records. Statistical analysis was applied to evaluate the correlation between the progression free survival and treatment modalities. RESULTS: Nine of the 16 patients were women (56.3%). Half of the patients had intracranially located tumors, whereas the other 50% of the sample had spinal (n=5) and sacral (n=3) chordomas. The median follow-up time was 51.7 months. Recurrence was observed in 50% of patients, while the median recurrence time equaled to 27.6 months. Multivariate analysis results showed that age, gender tumor size, intra or extracranial location of tumor, treatment modalities, subtotal or grosstotal resection of tumor, radiotherapy dose, and techniques were not associated with recurrence. On the other hand, 2 patients are still under chemoterapy (imatinib, bevacizumab) without evident of recurrent disease. CONCLUSION: Despite the fact that surgery remains to be the cornerstone of treatment, total resection is not reasonable for all patients with chordomas. For this reason, adjuvant treatment for ensuring local control is highly important. If the residual tumor is of a small volume, SBRT may provide more advantages. Targeted treatment or chemotheapeutic agents may also be benifcial for maintanence therapy. As the clinical awareness about chordomas is based on our series, aggressive multi-modality treatment options should be applied in the adjuvant therapy. KEYWORDS: Chordoma, Radiotherapy, Radiosurgery, Surgery, Imatinib, Bevacizumab Corresponding author: Volkan DEMIRCAN  nvdemircan@hotmail.com Original Investigation █ INTRODUCTION C hordomas are known as rare malign tumors typically present in the skull base, axial skeleton or sacrococcy- geal region. They usually emerge from the remnants of embriyonic notochord (11). Chordoma is composed of 1-4% of all bone malignancies (18). It can be observed in the sacral region (50-60%), followed by the skull base area (25-30%) (7). It represents a tumor with lobules as well as vacuolated, moderately atypical, neoplastic cells across a myxoid stroma separated by fbrous bands. It mainly develops in the cranial and caudal ends of the axial skeleton, having quite a slow, ag- gressive and locally invasive character (10). Despite the histologically low-grade nature of chordoma, this locally invasive characater of tumor causes malignant activity patterns and poses a high risk for recurrence of the disease. A wide surgical resection is still considered standard and primary treatment of chordomas, with application of postoperative radiotherapy for the residual macroscopic disease. En-bloc resection or any other resection of tumor cannot be operated because of the anatomical location of mass. In such cases, Muge AKMANSU : 0000-0002-5747-2522 Gokhan KURT : 0000-0002-2773-056X Volkan DEMIRCAN : 0000-0001-9632-180X Ertugrul SENTURK : 0000-0002-7186-731X DOI: 10.5137/1019-5149.JTN.24406-19.4