A study from Johns Hopkins School of Medicine shows that there is significant value in performing additional PET/CT scans in the follow-up of lung cancer patients.

The study, which was published in the February issue of the Journal of Nuclear Medicine, was carried out in the context of a recent decision by the Centers for Medicare and Medicaid Services (CMS) to limit coverage to three FDG PET/CT scans when used to guide subsequent management of anti-tumor treatment strategy, following initial anticancer therapy. It is up to local Medicare administrative contractors to determine whether additional scans will be covered.

The researchers, led by Rathan Subramaniam, MD, PhD, carried out a retrospective study in which they looked at 1,171 patients with biopsy-proven lung cancer and had FDG PET scans during the period between 2001 and 2013. Of those, 85 patients had four or more follow up PET/CT scans (for a total of 285 follow-up scans).

Of those 285 scans, 149 were interpreted as positive and 136 as negative for recurrence of metastasis. PET/CT identified recurrence or metastasis in 44.3% of scans performed without prior clinical suspicion and ruled out recurrence or metastasis in 24.2% of scans performed with prior clinical suspicion. The PET/CT scan resulted in a treatment change in 28.1% (80/285) of the patients. New treatment was initiated for 20.4% (58/285) of the scans, treatment was changed in 5.6% (16/285), and ongoing treatment was stopped in 2.1% (6/285).

“Although the value of FDG PET/CT has been established in the follow-up of patients with lung cancer, this study specifically looks at the value of the fourth and subsequent follow-up PET/CT studies, which has not been addressed in any prior studies,” said Subramaniam in a statement. “We now need to establish similar evidence for other human solid tumors.”