New research suggests clinicians should increase follow-up times for evaluating ground-glass nodules (GGNs) found on CT from one to three years, according to a study published in Radiology.
The researchers created a simulation model for one million hypothetical patients with GGNs who would have undergone follow-up as directed by the Lung Imaging Reporting and Data System (Lung-RADS) recommendations. They were on average 64 years old.
Mark M. Hammer, MD, of Brigham and Women’s Hospital in Boston, and colleagues tested the effectiveness of annual versus three-year interval follow-up of Lung-RADS category 2 nodules. They also compared three treatment strategies: stereotactic body radiation therapy (SBRT), surgery and no therapy.
A total of 2.3 percent of nodules were clinically significant malignancies, and 30 percent of Lung-RADS category 4B or 4X nodules were clinically significant malignancies. Overall survival at 10 years was 72 percent with annual follow-up and 71 percent with three year follow-up.
“Our results argue for raising the follow-up interval for GGNs to 3 years,” Hammer et al. wrote. “While there is a high rate of malignancy in these [GGN] nodules at biopsy, the rate of clinically significant malignancy is lower, and, overall, these malignancies demonstrate an indolent course.”
The team found SBRT the most effective treatment. Overall survival in patients receiving SBRT was 80 percent, compared to 79 percent and 74 percent after surgery and no therapy, respectively.