This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Brachytherapy, Subject name: Radiology
[{'content': 'All are used in brachytherapy EXCEPT: \nSelect and explain. \nA. I125, B. I131, C. Cs137, D. Iridium 192', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ANSWER: (B) I131REF: APPENDIX-67 for "ISOTOPES USED IN RADIOTHERAPY" APPENDIX - 67Isotopes Used in RadiotherapyIsotopeHalf LifeUsesTechnetium 996 hoursBone scanCobalt 60 (Artificial)5.27 yearsTeletherapy & BrachytherapyIodine 12313 hoursRadioactive iodine uptakeIodine 12560 daysBrachytherapy (P)Iodine 1318 daysRadiotherapyIodine 1322.3 hours (min) Radium1622 years (max)Not used now a daysAu 198 (gold)2.7 daysBrachytherapy (P)Pd 103 (palladium)17 daysBrachytherapy (P)Cesium 1319.7 daysBrachytherapy (P)Cesium 13730 yearsTeletherapy 81 Brachytherapy (T)Iridium 192 (Artificial)74 daysBrachytherapy (T)Strontium 9029 yearsBrachytherapy (T)Radon 2223.8 daysBrachytherapy (T)Brachytherapy can be of two types, permanent implant (P) or temporary implant (T)', 'role': 'assistant'}]