The Impact of Low-Dose Cranial Boost on the Long-Term Outcomes of Adult Patients with High-Risk Acute Lymphoblastic Leukemia Undergoing Total Body Irradiation and Allogeneic Hematopoietic Stem Cell Transplantation.

Abstract

PURPOSE:

Total body irradiation (TBI) is an integral part of the conditioning regimen for patients with acute lymphoblastic leukemia (ALL) undergoing allogeneic, hematopoietic, cell transplantation (allo-HCT). There are conflicting data in the literature regarding the utility of a cranial irradiation boost in high-risk adult ALL without evidence of preexisting central nervous system (CNS) involvement. This study investigates the posttransplant clinical outcomes of patients with high-risk adult ALL undergoing TBI conditioning for allo-HCT with or without a whole-brain boost, without overt CNS involvement at the time of diagnosis.

METHODS AND MATERIALS:

A retrospective cohort study was conducted using a medical record analysis. We identified 58 patients who were treated between January 1998 and December 2016, and met our preset inclusion criteria of adults (age >18 years old) who carried a pathologically confirmed diagnosis of CNS-negative, high-risk ALL, who underwent hematopoietic stem cell transplantation with TBI conditioning. A multivariate analysis of correlation between patient outcomes and collected categorical variables was assessed with stepwise Cox logistic regression. Survival analyses were assessed using the Kaplan-Meier technique with a log-rank test.

RESULTS:

With a median follow-up time of 5.3 years, there was a statistically significant improvement in actuarial 7-year CNS relapse-free survival (100% vs 76.4%; P = .043) in favor of patients undergoing a cranial boost. There was no statistically significant improvement in 7-year progression-free survival (78.3% vs 62.5%; P = .076) or overall survival (49.4% vs 43.5%; P = .921) with versus without a cranial boost. On multivariate analysis, the presence of a cranial boost was the only identified variable with an independent relationship to CNS relapse-free survival.

CONCLUSIONS:

Adult patients with high-risk, CNS-negative ALL were found to have a statistically significant improvement in CNS relapse-free survival and a trend toward improved progression-free survival with the inclusion of a cranial boost with TBI pretransplant conditioning. Our data indicate that further investigation into the use of cranial boost in this patient population is warranted.

• Authors: Justin M Famoso, Joel L Grow, Brady Laughlin, Emmanuel Katsanis, Baldassarre Stea
• Journal: Practical radiation oncology (Pract Radiat Oncol) Vol. 9 Issue 3 Pg. e283-e289 (May 2019) ISSN: 1879-8519 [Electronic] United States
• PMID: 30578956 (Publication Type: Clinical Trial, Journal Article)
• Copyright: Copyright © 2018 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Topics

• Adolescent
• Adult
• Cranial Irradiation (adverse effects, methods)
• Disease-Free Survival
• Female
• Hematopoietic Stem Cell Transplantation (methods)
• Humans
• Male
• Middle Aged
• Precursor Cell Lymphoblastic Leukemia-Lymphoma (mortality, radiotherapy, therapy)
• Radiotherapy Dosage
• Retrospective Studies
• Transplantation Conditioning (methods)
• Transplantation, Homologous (methods)
• Whole-Body Irradiation (adverse effects, methods)