Archbishop Daniel Buechlein of Indianapolis won't be able to greet the pope later this month.
The archbishop is being treated for Hodgkin's disease. He's not healthy enough to join the crowds of Roman Catholics and others who will greet the pope in Washington, D.C., and New York City during his visit to the United States.
Buechlein received his fifth chemotherapy treatment on Friday.
Buechlein is the spiritual head of some 230,000 Roman Catholics in 39 counties across central and southern Indiana.
Pope Benedict's visit will include celebrating outdoor Masses for thousands of worshippers at Nationals Park in Washington on April 17th, and at Yankee Stadium in New York on April 20th.