PET/CT: Four or more follow-up scans alter treatment in over 28% of lung cancer cases

A new study suggests the use of not only three, but four or more PET/CT evaluations during follow-up for lung cancer, as the research revealed that additional PET/CTs changed patient management in 28.1 percent of cases, the Society of Nuclear Medicine and Molecular Imaging (SNMMI) announced Feb. 18. 

CMS’s June 2013 decision to cover three follow-up FDG PET scans for most oncologic applications laid the foundation for more careful study of just how many scans may be necessary--and warranted--to provide the best cancer care for not just lung cancer patients but those with other forms of cancer, as well.

In a retrospective study, a team of researchers including Rathan Subramaniam, MD, PhD, associate professor of radiology, oncology, head and neck surgery, and health policy and management at Johns Hopkins School of Medicine in Baltimore, evaluated 1,171 cases of lung cancer patient management from 2001 to 2013 to assess the benefit of four or more PET/CTs during follow-up. They published their findings in the February 2015 issue of the Journal of Nuclear Medicine. . 

“This study showed us that follow-up PET/CTs, in this case the fourth and subsequent PET/CTs, were able to provide added value and additional information for the critical judgment of whether a person had disease or not,” Subramaniam told Health Imaging. “They also proved useful in changing the management of the disease.”

This evidence could potentially influence the future standard of cancer care and the likelihood of reimbursement for additional scans, because, for the first time, researchers have data to back it up.

Results of the study showed that among the 1,171 biopsy-proven cases of lung cancer, 85 patients, or 7.3 percent, received four or additional follow-up PET/CT scans to evaluate their cancer. The fourth follow-up PET/CT scan was performed at a median of 31.4 months. A grand total of 285 scans above and beyond the third follow-up scan were reported. The fourth or subsequent FDG PET/CT scan was interpreted as positive 52.28 percent of the time, or 149 scans out of 285, and these additional PET/CTs were able to identify unsuspected recurrent or metastatic disease in 24.2 percent of scans.

Treatment changes resulted from 80 of the scans, including new or additional treatment prescribed as a result of 58 of the additional scans. Changes were made to treatment planning and the administration of chemotherapy and other forms of therapy after 16 of the scans, and cessation of treatment was reported following six of the 285 scans performed. A total of 55.3 percent of the participating patients died during that span of study from 2001 to 2013.

Subramaniam explained that while this data is still relatively raw, it could have an impact on the reimbursement of the fourth or additional FDG PET/CT scans as decided by local Medicare Administrative Contractors. Research has already begun to replicate this study for colorectal cancer and, in time, breast cancer.

“In any field, you want to see multiple independent studies provide similar answers in order to get broad, robust evidence development.”