CNAO - Centro Nazionale di Adroterapia Oncologica
Light ion therapy software for data exchange
This project is focused on creating a common software bus that shall enable any present and future package to easily interconnect in a complex and widely distributed hadron therapy facility environment. An integral part of the project is the specification of protocols to be used in the facility’s control system. These protocols should allow for data exchange, assurance of security and privacy, and discovery of devices. The design and development of libraries to support these protocols and enable to automatically connect and operate devices is also expected. As a result, an environment for supervision and monitoring of event creation and distribution will be developed. To achieve this goal, the Fellow shall research and be trained in existing software solutions for event creation, event decoding and event relaying in slow workflow environment and FPGA based solutions for the same tasks in fast workflow environments. Novel control systems for a medical accelerator facility demand the increase of the monitoring via specification of tools that help with visualization and construction of workflows. To overcome this challenge, one part of the Fellow’s research includes the design and development of a graphical environment that enables the description of workflows composed of several medical accelerator activities. The graphical environment shall be backed by an xml based language, described by the Fellow, allowing for the description of the workflow states and events for each connected device. Finally, one of the major concerns in the medical environment is the assurance that programs and components are functioning as per specification. In order to address this concern, the specification of programs that validate the set of tools that altogether constitute the Fast Workflow Manager is foreseen. These specification programs shall, furthermore, be able to evaluate tools in several different environment configurations, because the means of accessing data and devices in the accelerator complex is manifold.
Tumour tracking in particle therapy
The potential of treating mobile tumors by means of active particle beam scanning depends on the capability of overcoming a set of technological and methodological issues related to the geometric uncertainties and related dosimetric effects caused by motion. Since organ motion not only affects the target position, but also the position and the density of the surrounding anatomical structures, the radiological path length (i.e. the cumulated density) of tissues traversed by the particle beam may change as a function of time, both intrafractionally and inter-fractionally. In addition, the dynamic motion of the beam overlaps with target motion creating an interplay pattern, which ultimately leads to dose inhomogeneities, thus potentially degrading target volume dose coverage. Breath-hold irradiation and beam gating (with rescanning) represents motion suppression/compensation strategies already available (though in limited cases) in clinical practice. Conversely, beam tracking, which entails the real-time modulation of the beam direction and energy, in order to accurately conform the dose on an intra-fractionally moving target, requires further validation before clinical application. The key challenge is represented by the integration of a highly performing motion monitoring technique with an efficient solution for beam in-plane tracking and energy modulation.
CNAO has a dedicated optical motion detection device. Following preliminary studies at GSI and CNAO based on internal-external correlation models for tumor localization and dedicated interfacing between motion monitoring and beam delivery systems, additional activities are required to fill the gap between phantom studies and clinical application of tumor tracking in particle therapy.
Image courtesy of CNAO