Non-pharmacological treatments of oral mucositis in onco-hematological patients undergoing autologous/allogeneic stem cell transplantation: A systematic review without meta-analysis

Introduction : Oral mucositis is a common and debilitating complication in patients undergoing hematopoietic stem cell transplantation (HSCT). Although non-pharmacological interventions are increasingly implemented in supportive care, HSCT-specific evidence remains fragmented. This review aimed to synthesize current evidence on non-pharmacological strategies for preventing and managing oral mucositis in adult patients undergoing autologous/allogeneic HSCT. Methods : A systematic search of PubMed, Embase, and Scopus was conducted for quantitative primary studies published up to August 2025. Two reviewers independently screened the studies, assessed methodological quality using the Joanna Briggs Institute (JBI) criteria, and evaluated the risk of bias. A narrative synthesis was conducted in accordance with the Synthesis Without Meta-Analysis (SWiM) reporting guideline. Results : Twenty-seven studies met inclusion criteria. The non-pharmacological interventions were categorized as (a) oral cryotherapy (OC), (b), low-level laser therapy (LLLT), and (c) other biologically derived or plant-based treatments. OC demonstrated consistent reductions in Grade 3-4 oral mucositis, particularly during high-dose melphalan conditioning. Prophylactic LLLT reduced incidence of Grade ≥ 2 oral mucositis, although parameter heterogeneity was notable. The other treatments demonstrated effectiveness in reducing both severity and duration of oral mucositis. Conclusions Oral cryotherapy and prophylactic photobiomodulation (PBM) demonstrate the most consistent evidence for preventing moderate-to-severe oral mucositis in adult HSCT recipients. Plants-based and biologically derived adjunctive interventions show preliminary promise but require further high-quality trials. Standardized intervention protocols and core outcome reporting are essential to strengthen clinical guidance. PROSPERO registration number: CRD42023482768.