Medical Physics Seminar – Monday, January 23, 2012
From Radiological Image to Molecular Image Guided Radiation Therapy
Lei Xing, Ph.D., (guest of Dr. Weibo Cai)
Jacob Haimson Professor, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305
Recent technical advances in planning and delivering intensity modulated radiation therapy (IMRT) & volumetric modulated radiation therapy (VMAT) provide unprecedented means for producing exquisitely shaped radiation doses that closely conform to the tumor dimensions while sparing sensitive structures. The need to improve targeting in radiation treatment has recently spurred a flood of research activities in image-guided radiation therapy (IGRT). These techniques combine new imaging tools, which interface with the radiation delivery system through hardware or software, and state-of-the-art IMRT/VMAT, and allow physicians to optimize the accuracy and precision of the radiotherapy by adjusting the radiation beam based on the true position of the target tumor and critical organs. With IGRT, it is also possible to take tumor motion into account during RT planning and treatment.
Briefly, IGRT developments are focused in five major areas: (1) biological imaging tools for better definition of tumor volume; (2) time-resolved (4D) imaging techniques for modeling the intra-fraction organ motion; (3) on-board imaging system or imaging devices registered to the treatment machines for inter-fraction patient localization; (4) real-time imaging for monitoring intra-fractional organ motion and therapeutic guidance6; (5) new radiation treatment planning and delivery schemes incorporating the information derived from the new imaging techniques. In this talk I will highlight recent developments of various available IGRT techniques, summarize our recent research on various related subjects, such as real-time image guidance, new volumetric imaging and planning tools, and respiration-gated RT. I will also present our recent work on molecular imaging and nanomedicine, as well as their potential applications in image guided interventions.