The detection of extranodal, soft tissue, bone, and spleen involvement at baseline on PET/CT imaging predicted poor survival outcomes in patients with untreated follicular lymphoma, a retrospective study found. The findings were published online April 21, 2019, in the American Journal of Hematology.

The study authors retrospectively reviewed 613 cases of untreated follicular lymphoma between 2003 and 2016 for which PET/CT imaging datasets were available. Study authors evaluated location and number of extranodal sites, patterns of bone involvement, and splenic involvement at baseline and compared these data to survival outcomes for cases.

Related Articles

At baseline using PET/CT imaging, 301 cases (49%) were identified as having extranodal involvement and 171 cases (28%) as having spleen involvement. Most cases (77%) with extranodal involvement had it at only one site, and among the cases with extranodal involvement, 68% had bone involvement and 32% had involvement at an extranodal site other than bone.

Continue Reading

According to multivariate analyses, the involvement of 2 or more extranodal sites (HR, 1.43; 95% CI, 0.99-2.07; P =.06), the presence of focal or multifocal on diffuse pattern of bone involvement (HR, 1.71; 95% CI, 1.10-2.65; P =.02), the involvement of spleen (HR, 1.49; 95% CI, 1.11-2.00; P <.01), and the involvement of soft tissue (HR, 1.67; 95% CI, 1.06-2.62; P =.03) each independently predicted inferior EFS among cases with untreated follicular lymphoma. A separate multivariate analysis showed that the number of extranodal sites independently predicted worse overall survival (HR, 2.28; 95% CI, 1.01-5.18; P =.05).

“The presence of [2 or more extranodal] sites, bone, soft tissue, or splenic involvement predicts early clinical failure,” the study authors wrote in conclusion. “These results, when combined with other factors, may better identify high-risk patients and guide therapy.”


  1. St-Pierre F, Broski SM, LaPlant BR, et al. Detection of extranodal and spleen involvement by FDG-PET imaging predicts adverse survival in untreated follicular lymphoma [published online April 21, 2019]. Am J Hematol. doi: 10.1002/ajh.25493