My father has had treatment for lung cancer chemo and radiotherapy . sclc. He now just has scar tissue but is incredibly weak. His legs have lost all muscle and he has noticed black spots on his calves which are crusty. Last night my mother had to undress him for bed as he was so weak. He is 78 years old and lost over a stone in weight over the past 6 months. Should he go to hospital? The black marks are worrying.