{
  "abstract": "Background and Importance Building on Kwak’s 1 work on Relative Dose Intensity (RDI, received dose/theoretical dose) in DLCL, our study refines a prognostic model. We conducted a tree-structured survival analysis integrating RDI with the clinical variables IPI, EPI, and SGA.This approach identifies high risk patient subgroups by analysing the combined impact of chemotherapy delivery and clinical status.Aim and Objectives The main objective is to use tree-structured survival analysis to determine an RDI cut-off and characterise patients below this threshold using the other covariates.Material and Methods Chemotherapy doses, extracted from the Human Bimind software, were converted to mg/m2/week to calculate the RDI.A tree-structured multivariate survival analysis (R software, version 4.2.2) was then developed with the dual aim of:Establishing a ‘cut–off’ for RDI.Profiling patients below this threshold using the remaining covariates.Graphical analysis was performed for the three endpoints using the aforementioned covariates, employing both the multivariate model (presented here) and univariate models with single doses.Results In the multivariate model, the sole stratification factor for Overall Survival (OS) was the relative dose intensity (RDI) of doxorubicin (p<0.001, figure 1).Abstract 4CPS-138 Figure 1This RDI splits the population into two distinct groups:≥71% RDI: median OS (mOS) was not reached (74– NA).<71% RDI: mOS is 32 months (16−NA).For Event-Free Survival (EFS) and Progression-Free Survival (PFS), the first significant stratification factor was the IPI score (p=0.014).Patients with an IPI score ≤3 had a mPFS of 66 months (63− NA) and mEFS was not reached (64− NA).For patients with an IPI score 4/5, further factors emerged:For EFS: The RDI of cyclophosphamide was significant with a cut–off of 72.3% (p=0.02). Below this RDI, mEFS was 8 months (6−21) versus not reached (29− NA).For PFS: The doxorubicin RDI cut–off at 68% split the population into two groups with mPFS of 7 months (4−21) and 29 months (20− NA).Conclusion and Relevance Maintaining a doxorubicin RDI ≥71% is crucial for OS (mOS Not Reached vs 32 months).For EFS/PFS, risk stratifies by IPI score, with high risk patients showing poorer outcomes linked to low cyclophosphamide (mEFS 8 vs NA) and doxorubicin RDI (mPFS 7 vs 29 months).References and/or Acknowledgements 1. Kwak LW, et al. J Clin Oncol. 1990 Jun;8(6):963–77.Conflict of Interest No conflict of interest",
  "authors": [
    {
      "affiliations": [
        "Asugi, SC Farmacia PO Cattinara-Maggiore, Trieste, Italy"
      ],
      "name": "S Loiacono"
    },
    {
      "affiliations": [
        "Asugi, UCO Ematologia, Trieste, Italy"
      ],
      "name": "E Lucchini"
    },
    {
      "affiliations": [
        "University of Trieste, Department of Economics- Business- Mathematics- and Statistics ‘Bruno De Finetti’, Trieste, Italy"
      ],
      "name": "L Egidi"
    }
  ],
  "title": "4CPS-138 Diffuse large B-cell lymphoma: a retrospective, relative dose intensity-based tree-structured analysis",
  "uid": "5ce19bdf-9522-5023-b28d-d8a95b1ef806"
}