Complex sentence: Castle Hill Hospital was extended by the addition of an oncology and hematology unit in 2009, "The Queen's Centre for Oncology and Haematology", a cardiac unit and additional cancer centre for teenage patients in 2011.
Split into simpler sentences: Castle Hill Hospital was extended by the addition of an oncology and hematology unit in 2009, "The Queen's Centre for Oncology and Haematology". A a cardiac unit and additional cancer centre for teenage patients in 2011.