This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Radiology
[{'content': 'High brachytherapy is \nSelect and explain. \nA. 0.4-2 Gy/hour, B. 12 Gy/hour, C. 2-12 Gy/hour, D. 0.01-0.3 Gy/hour', 'role': 'user'}, {'content': 'Answer: B \nExplanation: According to ICRU repo 38, treatment dose rates fall into three categories * Low Dose Rate (LDR) brachytherapy ranges between 0.4 and 2 Gy/h. However, in routine clinical practice, LDR brachytherapy is usually delivered at dose rates between 0.3 and 1 Gy/h. This is compatible with conventional manual or automatic afterloading techniques. * Medium Dose Rate (MDR) brachytherapy ranges between 2 Gy/h and 12 Gy/h. MDR can also be delivered by manual or automatic afterloading, although the latter is far more frequent. * High Dose Rate (HDR) brachytherapy delivers the dose at 12 Gy/h or more, and only automatic afterloading can be used because of the high source activity.(Ref: Radiobiology of Brachytherapy and the Dose-Rate Effect by JJ Mazeron et al, 95)', 'role': 'assistant'}]