Lung Exposure - is 3 cm too much?

svz

Hi there - I just finished my chemo yesterday and will be starting radiation next Monday.  I went in for my simulation yesterday and have a bit of a concave chest in between my breasts.  Because of this, it is difficult for the machine to get a good angle and there was a possibility that I was going to have to deflate my expander on the non treated side in order to get a good angle on the breast.  However, with the simulation, my doctor figured out that he can do it without deflating but I will have 3 cm of lung exposure.  I know the goal is to minimize exposure to the lung, but he said up to 4 cms is acceptable so we are well within range. 

 My question is - has anyone heard otherwise about whether or not 3 cm is too much exposure, what is the risk of this much lung exposure, and would it be worth it to deflate my expanders to have less lung exposed to radiation. Thoughts?

 Thanks,

Shelley