Diagnosed lung cancer

Hi everyone 

hoping someone can shed some light here, my Nan was diagnosed today with a 13mm tumour as being lung cancer. It is situated in the left lower lobe, with a smaller 7mm tumour underneath. There is also traces in her lymph nodes. The consultant said he is concerned about the bigger one as it’s active and is growing quickly. He did say it’s not aggressive (how he knows that I can’t work out) it’s to big to remove and it’s too deep to take a biopsy. They have now refered my Nan to the cancer specialists at another hospital where in his opinion she will undergo radiotherapy. He believes she is to unwell to have chemotherapy. This is a secondary cancer as she had bowel cancer. Does anyone know what will happen next? How do they know it’s not aggressive and what stage it is without doing a biopsy? Is radiotherapy likely to cure her. Hoping for any advice please, 

janine xxxx