RESUMO
Cyberattacks are increasing year after year and many organizations, including hospitals, are becoming targets. Radiation oncology is especially vulnerable because of the reliance on computer and network capabilities to transfer relevant patient information for safe and effective patient treatment. In early 2019, our institution was hit by a ransomware attack that brought down our oncology information system (OIS). Although we were not fully prepared for such an attack, a total of 69 treatment fractions occurred without our OIS thanks to the quick development of a contingency plan and the ability to restore the patients' records. The OIS was recovered by the manufacturer 4 days after the attack. We also have developed a contingency plan and outline important considerations for institutions trying to prepare for unexpected downtime such as a cyberattack.