In aggressive non-Hodgkin lymphomas, the result of positron emission tomography (PET) with [18F]fluorodeoxyglucose performed after a few cycles of chemotherapy has been shown to correlate with long-term treatment outcome. The PETAL trial investigates whether a change in treatment protocol may improve the outcome of patients with a positive scan after two cycles of (R-)CHOP. Such patients are randomized to receive a further six cycles of (R-)CHOP or six blocks of the B-ALL protocol, a regimen for the treatment of Burkitt lymphoma. Precautions taken to minimize false-positive interim-PET results include adherence to a 3-week interval between chemotherapy and interim-PET scanning, avoidance of hematopoietic growth factors, and SUV-based rather than visual interim-PET assessment. So far, 175 patients have been enrolled of whom 128 have reached interim-PET scanning. In patients with a positive scan, relapses were six times more frequent than in patients with a negative scan. Recruitment into the trial continues.
Trial registration: ClinicalTrials.gov NCT00554164.