Q. A 68-year-old man comes to his physician’s office for a routine checkup with no complaints. His temperature is 98.4°F (36.8°C), heart rate is 80/min, respiratory rate is 14/minute, and blood pressure is 120/80 mm of Hg. Physical examination shows a non-tender enlargement of bilateral supraclavicular and axillary lymph nodes. Mild non-tender splenomegaly is noted on abdominal examination. Laboratory investigations are shown below. A peripheral blood smear shows a majority of cells that are mature-appearing small lymphocytes. Peripheral blood flow cytometry shows positive expression of the B cell-associated antigens CD19 and CD20. What is the next best step in the management of this patient?