Imaging for Physicists

Summary

• FDG-PET and CT are the prime imaging modalities in lung cancer • PET improves the accuracy of staging – high negative predictive value for mediastinal lymph nodes • More consistent contouring is possible with PET-CT – volume may increase (include lymph nodes) and decrease (avoid atalectasis) – systematic approach to thresholding (e.q. source-to-background ratio) – validation with pathology is essential • 4D imaging CT is required for precise delineation of the tumor and characterizing the extent of motion – Tumor motion is not detected directly; surrogates are used