Post-therapy ¹⁸F-fluorodeoxyglucose positron emission tomography for predicting outcome in patients with peripheral T cell lymphoma.

The International Harmonization Project on Lymphoma recommends (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) for the routine assessment of treatment efficacy in patients with FDG-avid lymphomas such as Hodgkin's and diffuse large B cell lymphomas. The utility of FDG-PET in predicting outcomes in patients with peripheral T cell lymphomas (PTCL) has not been fully elucidated. We retrospectively determined the predictive value of FDG-PET after first-line treatment (post-PET) for outcome in PTCL. Of the 36 patients enrolled, 16 were histologically diagnosed with PTCL not otherwise specified and 20 were diagnosed with angioimmunoblastic T cell lymphoma. All patients received curative-intent anthracycline-containing chemotherapy regimens. Post-PET images were visually evaluated by local nuclear medicine physicians. The median observation period for the surviving patients was 44 months. Positive and negative post-PET results were obtained in 31 % (11/36) and 69 % (25/36) of patients, respectively. The 3-year progression-free survival rates in the positive and negative post-PET result groups were 18 % and 62 %, respectively (P < 0.001). Nine of the 11 patients in the positive post-PET result group experienced progressive disease (PD) (positive predictive value, 82 %), whereas 16 of the 25 patients in the negative post-PET result group did not experience PD (negative predictive value, 64 %). The 3-year overall survival rates in the positive and negative post-PET result groups were 44 % and 84 %, respectively (P = 0.03). Our findings indicate that post-PET is predictive of outcome in patients with PTCL.