MRI spine results, possible lung mass?

Yesterday I had an MRI of my thoracic spine and today I received the results.  My thoracic spine is ok, no mets at least, but the report states that I have paranchymal scarring versus a mass at the left lung apex.  I had left sided breast cancer with radiation to my breast, chest wall, axilla and supraclavicular nodes.  The radiation onc said that he missed my heart but my left lung was affected some.  Today, my PC said that this could be scarring from the radiation.  But I am stil afraid that it may be either mets or lung cancer.  After 2 months of back pain and fear of spinal mets, now another scare.  Tomorrow I have a CT scan with contrast to check out this "mass".  Has anyone else had anything like this?  I am praying that this is just scarring from the radiation!