Utility of 18Fluoro-Deoxyglucose Positron Emission Tomography for Prognosis and Response Assessments in a Phase 2 Study of Romidepsin in Patients With Relapsed or Refractory Peripheral T-Cell Lymphoma
Menée sur 130 patients atteints d'un lymphome T périphérique récidivant ou réfractaire et inclus dans un essai de phase II évaluant la romidepsine, cette étude évalue l'intérêt d'ajouter à un examen radiographique conventionnel une tomographie numérique par émission de positrons à base de fluorodésoxyglucose (18F) pour évaluer la réponse au traitement et la survie des patients
Background : For patients with peripheral T-cell lymphoma (PTCL), the value of 18fluoro-deoxyglucose positron emission tomography (FDG-PET) scans for assessing prognosis and response to treatment remains unclear. The utility of FDG-PET, in addition to conventional radiology, was examined as a planned exploratory endpoint in the pivotal phase 2 trial of romidepsin for the treatment of relapsed/refractory PTCL.
Patients and methods : Patients received romidepsin at a dose of 14 mg/m2 on days 1, 8, and 15 of 28-day cycles. The primary endpoint was the rate of confirmed/unconfirmed complete response (CR/CRu) as assessed by International Workshop Criteria (IWC) using conventional radiology. For the exploratory PET endpoint, patients with at least baseline FDG-PET scans were assessed by IWC+PET criteria.
Results : Of 130 patients, 110 had baseline FDG-PET scans, and 105 were PET positive at baseline. Use of IWC+PET criteria increased the objective response rate to 30% compared with 26% by conventional radiology. Durations of response were well differentiated by both conventional radiology response criteria (CR/CRu vs partial response [PR], P=.0001) and PET status (negative vs positive, P<.0001). Patients who achieved CR/CRu had prolonged progression-free survival (PFS, median 25.9 months) compared with other response groups (P=.0007). Patients who achieved PR or stable disease (SD) had similar PFS (median 7.2 and 6.3 months, respectively, P=.6427). When grouping PR and SD patients by PET status, patients with PET-negative vs PET-positive disease had median PFS of 18.2 vs 7.1 months (P=.0923)
Conclusion(s) : Routine use of FDG-PET does not obviate conventional staging, but may aid in determining prognosis and refine response assessments for patients with PTCL, particularly for those who do not achieve CR/CRu by conventional staging. The optimal way to incorporate FDG-PET scans for patients with PTCL remains to be determined.
Annals of Oncology , résumé, 2015