Radiobiological Analyse based on Cell Cluster Models

Key words: 
• tumor targeted radionuclide therapy /
• cell cluster model /
• radiobiological quantity /
• activity distribution

Abstract: The influence of cell cluster dimension on EUD and TCP for targeted radionuclide therapy was studied using the radiobiological method. The radiobiological features of tumor with activity lack in core were evaluated and analyzed by associating EUD，TCP and SF. The results show that EUD will increase with the increase of tumor dimension under the activity homogeneous distribution. If the extracellular activity was taken into consideration， the EUD will increase 47%. Under the activity lack in tumor center and the requirement of TCP=0.90， the α crossfire influence of ²¹¹At could make up the maximum(48 μm)3 activitylack for Nucleus source， but (72 μm)3 for Cytoplasm， Cell Surface， Cell and Voxel sources. In clinic， the physician could prefer the suggested dose of Cell Surface source in case of the future of local tumor control for underdose. Generally TCP could well exhibit the effect difference between underdose and duedose， but not between duedose and over dose，which makes TCP more suitable for the therapy plan choice. EUD could well exhibit the difference between different models and activity distributions，which makes it more suitable for the research work. When the user uses EUD to study the influence of activity inhomogeneous distribution， he should keep the consistency of the configuration and volume of the former and the latter models.