A cloud-based radiation therapy treatment planning system (TPS). The TPS changes the clinical workflow of the radiotherapy treatment planning process, by increasing the mobility and computational power of the treatment planning software and hardware architecture. The system is divided into computational components. A user device includes a light and flexible user interface, while the server side entails a hospital relay server, and/or a graphics processing unit cluster server. The TPS computational architecture enables the computational power of a GPU-cluster server on a tablet, laptop, or smartphone.