Madam, we thank the authors of the aforementioned comment on our article. Their keen interest is appreciated. 
We did not compare our fractionation schedules to any other trial but one can always do that and find out the biologically equivalent dosages. Obviously 5.4 G/day is far more aggressive than 5.7 G/week. Moreover UK FAST trial recruited breast conservation patients and not post mastectomy patients. 
Our trial was designed in 1997 and CT planning system was not available at our institute at that time. As most of our experience in breast cancer radiotherapy has been with Co 60 so it was quite natural and justified to use the same equipment for these aggressive protocols. 
Accrual in the protocol was started in 1998 and completed in 2004. Data analysis was performed in January 2008. So the follow up period varies from 4-10 years. Lost to follow up patients were included in dead category. 
Cardiac toxicity and mortality is very widely variable in the international data. We have already shown our results uptill now. Let us see what happens at 15 years. 
Multiple modalities have been tried to evaluate the cardiac toxicity in the world literature and none can be declared wrong. We had selected echocardiography by a single operator due to easy access, cost effectiveness and our confidence and experience in this modality. 
Thank you once again for your interest and comments. 
Abubaker Shahid 
Institute of Nuclear Medicine & Oncology, Lahore.