Interim 18-FDG-PET/CT failed to predict the outcome in diffuse large B-cell lymphoma patients treated at the diagnosis with rituximab-CHOP

Abstract

Role of interim-PET (I-PET) in diffuse large

Radiation Therapy in Primary Mediastinal B-Cell Lymphoma With Positron Emission Tomography Positivity After Rituximab Chemotherapy

“…A series of 37 patients with PMBCL, all evaluated with 18 FDG-PET at staging and restaging before RT and treated with R-CT followed by mediastinal RT, were included in the study.…”

“…The median interval between the end of R-CT and the start of mediastinal RT was 53 days (range, 20-86 days). 18 FDG-PET scans were acquired from the orbits to the proximal third of the thighs. Scans were acquired on a Philips Gemini Tomograph or a General Electric Discovery ST scanner.…”

“…In the past years, computed tomography (CT) or a combination of CT and 67 Gallium scans have been considered the gold standard. 18 Fluorodeoxyglucose positron emission tomography ( 18 FDG-PET) recently emerged as an important tool for chemosensitivity evaluation and response assessment in aggressive 18 FDG-avid lymphomas; its contribution in PMBCL management is therefore increasing, based on conventional response evaluation criteria defined for aggressive lymphomas and considering several limitations of morphologic radiologic findings in evaluating residual mediastinal tissue (12). A prospective international clinical trial lead by the collaborative International Extranodal Lymphoma Study Group, the IELSG 37 study (recently opened to accrual of patients) was designed with the aim of investigating the role of consolidation RT in 18 FDG-PET-negative patients.…”

“…18 Fluorodeoxyglucose positron emission tomography ( 18 FDG-PET) recently emerged as an important tool for chemosensitivity evaluation and response assessment in aggressive 18 FDG-avid lymphomas; its contribution in PMBCL management is therefore increasing, based on conventional response evaluation criteria defined for aggressive lymphomas and considering several limitations of morphologic radiologic findings in evaluating residual mediastinal tissue (12). A prospective international clinical trial lead by the collaborative International Extranodal Lymphoma Study Group, the IELSG 37 study (recently opened to accrual of patients) was designed with the aim of investigating the role of consolidation RT in 18 FDG-PET-negative patients. In this study, for 18 FDG-PET-positive patients (expected to be approximately 50%), the decision about further treatment is left to the treating physicians, underlining the uncertainty in the optimal management of patients with residual disease at functional imaging after R-CT.…”

“…A prospective international clinical trial lead by the collaborative International Extranodal Lymphoma Study Group, the IELSG 37 study (recently opened to accrual of patients) was designed with the aim of investigating the role of consolidation RT in 18 FDG-PET-negative patients. In this study, for 18 FDG-PET-positive patients (expected to be approximately 50%), the decision about further treatment is left to the treating physicians, underlining the uncertainty in the optimal management of patients with residual disease at functional imaging after R-CT. The introduction of an international validated scoring system for functional imaging interpretation, the Deauville 5-point system 13 and 14, might make it possible to better stratify patients on the basis of metabolic response, adapting the treatment strategy.…”