Safety and Efficacy of Primary Multisession Dose Fractionated Gamma Knife Radiosurgery for Jugular Paragangliomas Manjul Tripathi 1 , Rajashekhar Rekhapalli 1 , Aman Batish 1 , Narendra Kumar 2 , Arun S. Oinam 2 , Chirag K. Ahuja 3 , Harsh Deora 4 , Ashish Aggarwal 1 , Sandeep Mohindra 1 , Parwinder Kaur 1 , Rupinder Kaur 1 , Sandeep Bhatt 3 , Jenil Gurnani 1 - BACKGROUND: While multisession dose fractionated Gamma Knife radiosurgery (DFGKS) is common, its use has never been described for jugular paragangliomas (JP), which are notoriously difficult to treat. - OBJECTIVE: To define efficacy, safety, and complication profile of DFGKS in 2 or 3 consecutive sessions for the treatment of a cohort of 10 cases of JP. - METHODS: Between 2012 and 2017, 10 patients with JP were treated with DFGKS in 2 or 3 sessions, because it was not safe to treat the lesion in a single session because of the large volume or proximity to organs at risk. The small to medium-sized JP are treated with 16e22 Gy radiation, but the large-volume JP were treated with 23e25 Gy radiation dose. The Leksell G frame was kept in situ during the whole procedure. The tumor volumes on pretreatment and posttreatment imaging were compared, using the Leksell Gamma Plan treatment plan software to assess tumor progression. The patients were regularly evaluated for their clinical outcome with radiologic correlation. - RESULTS: The mean radiologic follow-up was 39 months (range, 12e78 months). The mean marginal dose for 3 fractions and 2 fractions was 7.64 Gy at 50% and 11.2 Gy at 50%, respectively. The mean tumor size was 29.9 cm 3 (range, 9.95e47.63 cm 3 ) at treatment and 21.9 cm 3 (range, 8.83e37.5 cm 3 ) at follow-up (suggestive of 26.7% reduc- tion). Tumor control was achieved in all patients (100%). Of 110 potential neurologic problems (signs/symptoms) eval- uated (11 in each patient), 56 (50.9%) were present preop- eratively. Of them, 27 (48.2%) improved and 29 (51.8%) stabilized after treatment. There were 2 new-onset neuro- logic problems (of 110, 1.8%) attributable to treatment (new-onset headache and spinal accessory paresis). No patient had any permanent neurologic deterioration. - CONCLUSIONS: DFGKS for large-volume JP leads to acceptable progression-free survival, tumor control rate, and symptomatic improvement. It may be preferred to sur- gery or fractionated radiotherapy given its better safety, efficacy, and complication profile. INTRODUCTION Background/Rationale T he surgical management of jugular paraganglioma (JP) is often met with pessimistic outcomes in terms of both tumor control and morbidity profile because of topographic anatomy and tumor vascularity. The different modalities of management are microsurgical resection, Key words - Cranial neuropathy - Dose fractionated Gamma Knife radiosurgery - Jugular paraganglioma - Linear quadratic model - Radiosurgery Abbreviations and Acronyms AVM: Arteriovenous malformation CN: Cranial nerve DFGKS: Dose fractionated Gamma Knife radiosurgery GKS: Gamma Knife radiosurgery GTV: Gross tumor volume IMRT : Intensity modulated radiotherapy JP: Jugular paraganglioma LQ: Linear quadrantic MRI: Magnetic resonance imaging RRC: Radiosurgery Response Classification SRS: Stereotactic radiosurgery From the 1 Departments of Neurosurgery, 2 Radiotherapy, and 3 Radiodiagnosis, Post Graduate Institute of Medical Education and Research, Chandigarh and 4 Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bangalore, India To whom correspondence should be addressed: Manjul Tripathi, M.Ch. [E-mail: drmanjultripathi@gmail.com] Manjul Tripathi and Rajashekhar Rekhapalli are co-first authors. Citation: World Neurosurg. (2019). https://doi.org/10.1016/j.wneu.2019.07.090 Journal homepage: www.journals.elsevier.com/world-neurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved. WORLD NEUROSURGERY -: e1-e13, - 2019 www.journals.elsevier.com/world-neurosurgery e1 Original Article