PET imaging is often used after a first chemotherapy cancer treatment to show whether the treatment is working to reduce the spread of the cancer. Find out how PET imaging is one of the newest and most effective ways to identify whether cancer treatments are working with information from adoctor in this free video on chemotherapy and cancer treatments. Expert: Dr. David Cathcart Bio: Dr. David Cathcart has been an occupational medicine physician at Heartland Regional Medical Center in St …