Pulsoni A, Starza ID, Cappelli LV, et al. - Including 67 consecutive patients with stage I/II follicular lymphoma, researchers undertook this investigation, in which, involved-field radiotherapy (IF-RT) (24–30 Gy) was used to treat all patients included. Using polymerase chain reaction (PCR), real time quantitative PCR and digital droplet PCR, the participants were investigated for the presence of BCL2/IGH rearrangements. Rituximab (R) (375 mg/m², 4 weekly administrations) was given to patients with minimal residual disease (MRD) after IF-RT. A median follow-up of 82 months (17–196) was carried out. Patients with undetectable/low levels (< 10⁻⁵) of circulating BCL2/IGH+ cells at diagnosis and those who were persistently MRD− during follow-up experienced significantly better progression-free survival (PFS). Failure of standard IF-RT to induce an MRD-negative status in half of patients was evident. MRD− status was achieved in most patients after treatment with R and this was related to a significantly better PFS.