In radiotherapy planning, which statement correctly defines GTV, CTV, and PTV?

In radiotherapy planning, which statement correctly defines GTV, CTV, and PTV?

• A. GTV is gross tumor volume; CTV includes potential microscopic disease; PTV adds margins for setup and motion.
• B. GTV is gross tumor volume; CTV includes macroscopic disease; PTV adds margins for motion.
• C. GTV is gross tissue volume; CTV is clinical treatment volume; PTV is planned target volume.
• D. GTV is gross tumor volume; CTV excludes microscopic disease; PTV is planning tumor verification.

Answer: (A)