Baseline F-FDG PET/CT may contribute to the determination of initial treatment strategy for newly diagnosed follicular lymphoma.

Background: "Watch-and-wait" approach is an important management option in asymptomatic follicular lymphoma (FL) patients with low tumor burden. Since most FL lesions are FDG-avid, we wonder if F-FDG PET/CT at baseline can help to better choose the patients who can benefit from early chemotherapy. This study aimed to investigate the prognostic value of baseline F-FDG PET/CT in newly diagnosed FL patients treated with either watch-and-wait approach or chemotherapy.

Results: Patients received chemotherapy as initial treatment had higher Ann Arbor stage, higher incidence of extranodal involvement and bulky disease, more involved lymph nodes larger than 3 cm, and higher SUVmax, MTV, and TLG than those managed with watch-and-wait approach (p < 0.05). The median PFS and TTNT in patients received chemotherapy and under watch-and-wait did not show significant difference, however patients with MTV<111.66 mL or TLG<141.50 SUVbw*mL had significantly longer PFS and TTNT than those patients with MTV≥111.66 mL or TLG≥141.50 SUVbw*mL (p < 0.05). Further analysis revealed that for patients with TLG≥141.50 SUVbw*mL or MTV≥111.66 mL, those who received chemotherapy as initial treatment had a significantly longer PFS and TTNT than those managed with initial watch-and-wait approach (p < 0.05). However, for patients with MTV<111.66 mL or TLG<141.50 SUVbw*mL in baseline PET/CT, there was no significant difference in PFS or TTNT between patients who received chemotherapy and those under watch-and-wait.

Conclusion: Baseline F-FDG PET/CT may provide prognostic value and help to improve the decision-making of initial treatment plans for newly diagnosed FL patients.