International Journal of Research in Medical Sciences | February 2024 | Vol 12 | Issue 2 Page 566 International Journal of Research in Medical Sciences Gloi AM. Int J Res Med Sci. 2024 Feb;12(2):566-571 www.msjonline.org pISSN 2320-6071 | eISSN 2320-6012 Case Report HyperArc multiple brain metastases report Aime M. Gloi* INTRODUCTION Brain metastases are among the most common intracranial tumors in both adults and children, and they are typically treated with whole-brain radiotherapy. 1 A new method involving whole-brain and high-definition linac-based radiotherapy has been implemented in various clinics and hospitals to effectively treat multiple brain lesions in different regions of the brain. HyperArc is an isocentric VMAT planning and automated treatment technique that uses a high definition multileaf collimator (HDMLC) for stereotactic radiotherapy delivery. It utilizes a single isocenter and a combination of arcs and couch rotation, as well as non-coplanar beam arrangements to reduce peripheral doses. The optimization process includes an SRS automatic normal tissue objective (NTO) to enhance the dose decay between targets and minimize doses below 17% of the prescription from spilling. 2 The purpose of this report is to present the first successful HyperArc treatment delivery after whole-brain irradiation at our clinic. CASE REPORT Patient narrative The 73-year-old patient, who had a history of metastatic non-small cell lung cancer with multiple lesions, underwent whole-brain radiation therapy in April to target several areas of concern identified in the brain. She responded well to treatment and remained stable until an magnetic resonance imaging (MRI) in October of 2023 showed two new brain lesions which were consistent with metastatic disease. Furthermore, the patient had been experiencing intermittent headaches and occasional bouts of dizziness for quite some time and these symptoms had become a chronic condition. Despite these, there were no other changes in her neurological status or short-term Genesiscare, Modesto, California, United States of America Received: 16 December 2023 Revised: 06 January 2024 Accepted: 09 January 2024 *Correspondence: Dr. Aime M. Gloi, E-mail: agloi7288@gmail.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT This report presents the initial clinical experience with HyperArc, a novel modality that incorporates a non-coplanar, arc-based multileaf collimator (MLC) and automated treatment optimization and dose delivery. The study focuses on a patient who had previously received whole-brain radiotherapy. The effectiveness and challenges of HyperArc were assessed by evaluating various quality indices for stereotactic radiosurgery within the RTOG protocol, as well as an additional measure of toxicity in the form of the V12Gy volume. The HyperArc plan achieved quality indices of 1.13, 4.58, and 0.88 for CI, GI, and CIPaddick, respectively. The mean ICRU83 value was 0.17±0.01, and it remained consistent across all six lesions. The V12Gy value was equal to 8.76 cc. The HyperArc plan successfully met the constraints for organs-at-risk (OAR). These results suggest that HyperArc is a suitable modality for treating multiple brain metastases, as indicated by the quality indices and metrics. Additionally, V12Gy is a valuable indicator for assessing low-dose spillage. Keywords: HyperArc, RTOG quality indices, Brain metastases, Stereotactic radiosurgery DOI: https://dx.doi.org/10.18203/2320-6012.ijrms20240228