By Dr. Brian McDonough

PHILADELPHIA (CBS) — For years, many cancer patients have claimed they don’t think quite as clearly after chemotherapy as they did prior to the treatment.

It is a condition called Chemo Brain, and for a long time, many people thought it didn’t exist. Now, according to new information based on a retrospective study which looked at brain scans from 128 breast cancer patients, the PET and CT scans showed there were changes in brain metabolism after chemotherapy, suggestive of an effect on the brain.

This is important, because it supports the concerns that many patients have had, and it also will allow scientists and physicians treating patients to take a look at Chemo Brain and find ways to offset it.