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Geoffrey  Zhang

Geoffrey Zhang

Geoffrey Zhang
Associate Professor


Office: Moffitt Radiation Oncology, Moffitt Cancer Center 1083A
Phone: 813/745-4815



PhD, Physics, 1998, Carleton University, Ottawa, Canada
MS, Particle Physics, 1988, Institute of High Energy Physics, Beijing, China
BS, Nuclear Physics, 1983, University of Science and Technology of China, Hefei, China


  • Ventilation calculation using 4DCT and deformable image registration.
  • Four-dimensional (4D) dosimetry in radiotherapy.
  • Monte Carlo dose calculation in radiotherapy.
  • Medical image texture analysis (Quantitative Image Analysis)
  • Image guided radiotherapy.
  • Radiation dose delivery measurement in radiotherapy.

Deformable image registration (DIR) has been applied in radiotherapy for adaptive treatment planning, 4D dosimetry. Use of deformable image registration to establish the voxel correspondence among 4DCT images and calculation of local lung volume changes in a respiratory cycle led to high resolution pulmonary ventilation imaging using 4DCT data. We applied DIR in multiple research projects and published many peer-reviewed papers. Our ongoing research using DIR includes the use of functional lung information in treatment planning to spare normal lung volumes in radiotherapy, adaptive treatment when multiple image sets are used in the treatment course.

The Monte Carlo technique has been applied in TomoTherapy dosimetry for chest wall treatment. Also, Monte Carlo simulation was used to compare compensator-based IMRT and MLC-based IMRT. Several ongoing research projects apply this technique for accurate dose calculations when media heterogeneity or superficial region is involved.

Medical images possess a vast amount of texture information relevant to clinical practice. Medical image texture analysis is another research frontier in radiotherapy. The quantitative texture features can give additional information regarding the lesion’s histology, pathology, which can help in diagnosis and personalized treatment. We have a few ongoing research projects in this area.

Technologies used in radiotherapy update quickly. Safety is always the first consideration when apply the new technologies in treatment. Accurate dose delivery is an important aspect in safety. We are involved in accurate dose delivery verification method development research in image guided radiotherapy.