Radiology Brachytherapy is the internal radiation therapy procedure for treating tumors. All are used in brachytherapy, EXCEPT: A I 125 B I 131 C Cs 137 D Iridium 192 💡 Explanation Brachytherapy is the internal radiation therapy procedure for treating tumors. All are used in brachytherapy, EXCEPT: ✓ Correct Answer: B. I 131