Febrile Neutropenia (FN)

The goal of this clinical trial is to evaluate whether stopping antibiotic treatment early is safe in paediatric patients with cancer who develop high-risk febrile neutropenia but show good clinical evolution and low biomarker levels 48-72 hours after the episode. The main questions it aims to answer are: Is early discontinuation of antibiotics as safe as the standard strategy in terms of preventing invasive bacterial infections (such as sepsis, microbiologically documented infection, ICU admission, or death)? Does this strategy reduce the number of days on antibiotics without increasing infection-related complications? Researchers will compare early antibiotic discontinuation with the standard care strategy to see whether the early-stop approach provides similar safety while reducing antibiotic exposure. Participants will: Receive standard initial antibiotic therapy for febrile neutropenia. Undergo clinical and biomarker evaluations (including CRP and PCT). Be randomly assigned to: Experimental group: early discontinuation of antibiotics, or Control group: continuation of the standard antibiotic strategy. Be followed for 28 days after randomisation to monitor safety outcomes and treatment effects.

The goal of this clinical trial is to learn if a personalized duration of antibiotic therapy, based on clinical stability, is as effective as a standard duration of at least 10 days in hospitalized patients with hematologic malignancies (such as leukemia or lymphoma) who develop febrile neutropenia and Gram-negative bacteraemia. The main questions it aims to answer are: * Can a personalized antibiotic duration increase the number of days free from anti-Gram-negative therapy within 28 days without compromising patient safety? * How does the duration of antibiotic therapy (short vs. prolonged) affect the rate and modality of gut microbiota reconstitution? Researchers will compare: * Group A (Personalized Duration): Antibiotics are stopped after the patient maintains clinical stability (no fever and stable vital signs) for 72 consecutive hours. * Group B (Standard of Care): Antibiotics are continued for a standard duration, typically at least 10 days, based on current clinical surveys and physician decision. Participants will: * Be randomized to receive either the personalized or the standard duration of antibiotic therapy once a Gram-negative infection is confirmed in the blood. * Be monitored for 28 days to assess for new fever episodes, recurrence of infection, and overall survival. * If participating in the microbiological sub-study, provide biological samples (blood, feces, and rectal swabs) at specific time points (at the onset of fever, at the end of treatment, and at day 28). * Undergo specialized laboratory testing (Whole Metagenomic Sequencing) on the collected samples to evaluate the evolution of their intestinal and blood microbiota and the presence of antibiotic-resistant genes.

The goal of this clinical trial is to Primary Objectives: 1. To compare the incidence of febrile neutropenia in patients with non-Hodgkin's lymphoma who received early or late granulocyte colony-stimulating factor (G-CSF) during standard chemotherapy in a multicenter study 2. To determine the incidence of leukopenia and neutropenia in patients with non-Hodgkin's lymphoma who received early or late G-CSF during standard chemotherapy in a multicenter study Secondary Objectives: 1. To determine changes in white blood cell, hemoglobin, and platelet levels in patients with non-Hodgkin's lymphoma who received early or late G-CSF during standard chemotherapy. 2. To determine the quality of life of patients with non-Hodgkin's lymphoma who undergoing standard chemotherapy and with neutropenia Researchers will compare the outcome between patients received either early G-CSF (within 72 hours) or late G-CSF (after 72 hours). All patients will be followed up to monitor for febrile neutropenia events, other hematological parameters and quality of life.