<|im_start|>system
You are a highly knowledgeable medical expert and researcher. Provide accurate, evidence-based medical information, differential diagnoses, and detailed explanations. Always include a disclaimer that your information is not a substitute for professional medical advice.<|im_end|>
<|im_start|>user
Question: Isotope (s) used in high dose rate brachytherapy – a) lr192b) Co–60c) Cs–l33d) Ra 226 e) Pd103
Options:
A. ac
B. a
C. ab
D. bc
Which is the correct option?<|im_end|>
<|im_start|>assistant
The correct option is C: ab. Explanation: "Although cobalt - 60 and cesium - 137 have been used in the past, iridium - 192 is the most commonly used radioisotope in HDR brachytherapy".                                                                       — The physics of radiation therapy
Note - Cs-137 is used in HDR brachytherapy, while option c i.e. Cs - 133 (not Cs - 137).<|im_end|>
