Greetings! My father 82 years old, completed 6 cycles of R-COP (every 21 days), and one Rituximab (Roche). He still has to receive one more Rituximab and thereafter will be placed on maintenance Rituximab (once in 2 months) for next two years. However, after completing one cycle of Rituximab he started having trouble with left eye, headache and left ear pain. His PET-CT scan month ago was clear except for one tiny lymoh node in thorax. Please advise