TLI in pediatric patients.

Abstract

Hematopoietic progenitor cell transplantation (HSCT) is a procedure used in different hematological diseases as part of the curative treatment, so the investigators propose a system of conditioning of reduced intensity based on total lymphoid irradiation (TLI) as an alternative to the classic total body irradiation (TBI) followed by haploidentical transplantation in patients compatible with a single HLA haplotype, as an alternative to patients who do not have an HLA compatible donor. A cohort of 25 patients with hematological disease underwent haploidentical HSCT from February 2015 to May 2018, conditioned with TLI from day -10 (2-4days of treatment) followed by thiotepa (5mg/kg/12h) and melphalan (70mg/m2/day) prior to HSCT and prophylaxis with ciclosporin (1.5mg/kg/12h). 2Gy/fraction was administered to complete 8Gy with IMRT and VMAT technique. 12% rejection of the transplant was obtained with acute GVHD < II (48%) and chronic GVHD 12%. No acute toxicity was recorded in irradiated patients and 56% survival of patients at the end of follow-up. Conditioning the haploidentical transplant with TLI, IMRT, and VMAT techniques compared with TBI and RT3D-C techniques is a feasible technique that helps inducing the necessary immunosuppression in patients with a high risk of graft rejection, minimal adverse effects, low incidence of GVHD, and high survival rate.