Prognostic significance of interim PET/CT based on visual, SUV-based, and MTV-based assessment in the treatment of peripheral T-cell lymphoma

BACKGROUNDS: The role of interim PET/CT in peripheral T-cell lymphoma (PTCL) is less identified compared to other subtype of lymphoma. This study prospectively investigated the prognostic accuracy of sequential interim PET/CT using visual and quantitative assessment to determine whether it provided prognostic information for the treatment of PTCL. METHODS: Sixty-three patients with newly diagnosed PTCL were enrolled, and 59 patients underwent interim PET/CT after three or four courses of induction treatment. The response of interim PET/CT was assessed by three parameters: the Deauville five-point scale (5-PS), ΔSUVmax, and ΔMTV2.5. RESULTS: Over a median follow up of 40.3 months, each assessment of interim PET/CT using the 5-PS, ΔSUVmax, and ΔMTV2.5 had predictive value for progression-free survival. To increase the predictive accuracy of interim PET/CT, we divided patients into three groups according to the sum of scores for three adverse responses based on the visual, SUV-based and MTV-based assessment: favorable, intermediate, and poor responder. The clinical outcome of patients in the favorable group was significantly superior to patients in the poor or intermediate group. CONCLUSION: Visual, quantitative SUV-based, and MTV-based assessment in interim PET/CT are valuable for early treatment response assessment in patients with PTCL, and the combined approach using the three parameters was more efficient in discriminating between patients with different survival outcomes compared with single-parameter assessment. TRIAL REGISTRATION: NCT01470066.