1. TheraPanacea (France) Paul Scherrer Institute (Switzerland)
2. České Vysoké Učení Technické v Praze (Czech Republic)
3. Paul Scherrer Institute
Changes and uncertainties of the irradiated anatomy are a major challenge for radiotherapy and particle therapy in particular. Tumours located in organs affected by breathing motion, heartbeat or peristalsis therefore are especially difficult to treat and in fact often show poor prognosis for the patients. Research on dedicated treatment strategies for such tumours has been conducted at GSI and many other centers, resulting in many different strategies for motion mitigation and compensation. Nearly all of this research has been conducted on patients lying on a couch for imaging and therapy. For upright patients, the anatomy as well as the organ motion of the abdomen and thorax changes significantly, which will have an impact on target coverage, OAR doses and the efficacy of motion mitigation strategies.
The objective of this PhD project is to investigate the impact of the upright patient posture on particle therapy of tumours in the thorax and abdomen. This includes studies on the changed anatomy, change motion patterns, as well as different motion mitigation strategies. GSI’s in house treatment planning system TRiP98 supports simulations and experimental planning of several motion mitigation strategies, including range-considering ITVs, gating, rescanning, tracking or dedicated 4D-plan libraries, as well as robust plan evaluation in the presence of periodic or variable motion.
The Doctoral Candidate will assess these effects on data acquired together with the project partners at PSI, ASG or HZDR, supported by secondments at PSI and Therapanacea. Based on treatment planning studies, recommendations for upright therapy of mobile targets will be developed, including patient positioning, beam directions, motion mitigation and plan adaptation strategies. The Candidate will finetune existing or develop additional motion mitigation strategies dedicated to upright therapy, also in support of particle arc therapy. Finally, the results will be validated in an experimental campaign at the clinical sites of the UPLIFT project using the phantom developed by DC15, and in collaboration with several other projects for immobilization, imaging, QA, and beam surveillance.
My name is Guangsheng Li, and I am originally from Henan, China. I studied Biological Engineering at Fudan University in China, where I gained my experience with radiotherapy. Throughout my studies, I developed a strong interest in particle therapy, which motivated me to pursue further research-oriented work. Now, I am pursuing my PhD at Technische Universität Darmstadt and am hosted by GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, under the supervision of Prof. Christian Graeff.
Within the UPLIFT project, I am working on the research topic entitled “Motion Mitigation in Upright Position”. The main objective of my work is to analyze the anatomical changes and motion patterns of thoracic and abdominal organs and tumors under upright position, and to investigate appropriate strategies to mitigate tumor motion in particle therapy. I chose this topic because it aligns closely with my academic background, allowing me to apply my previous experience and skills to this research.
Moreover, this project is also challenging, as upright radiotherapy is rarely applied to thoracic and abdominal tumors, and clinical experience in motion management for upright positioning is still limited. But I enjoy tackling such challenges and hope that my research will contribute effective motion mitigation strategies, ultimately helping to make upright particle therapy for tumors with large motion amplitudes a practical reality.
On a personal level, I am highly motivated by the opportunity to grow as an independent researcher and to contribute to work with a tangible impact on cancer treatment. This project represents an important step in my professional development, as it provides me with a unique platform to collaborate with other outstanding young researchers from around the world. I firmly believe that our collective efforts will lead to remarkable results in the future.
Outside academia, my hobbies include travelling, badminton and music, which help me maintain a healthy work-life balance.
