Comparison of High Doses of Total Body Irradiation in Myeloablative Conditioning before Hematopoietic Cell Transplantation.

Publication/Presentation Date

12-1-2019

Abstract

Malignancy relapse is the most common cause of treatment failure among recipients of hematopoietic cell transplantation (HCT). Conditioning dose intensity can reduce disease relapse but is offset by toxicities. Improvements in radiotherapy techniques and supportive care may translate to better outcomes with higher irradiation doses in the modern era. This study compares outcomes of recipients of increasing doses of high-dose total body irradiation (TBI) divided into intermediate high dose (IH; 13-13.75 Gy) and high dose (HD; 14 Gy) with standard dose (SD; 12 Gy) with cyclophosphamide. A total of 2721 patients ages 18 to 60 years with hematologic malignancies receiving HCT from 2001 to 2013 were included. Cumulative incidences of nonrelapse mortality (NRM) at 5 years were 28% (95% confidence interval [CI], 25% to 30%), 32% (95% CI, 29% to 36%), and 34% (95% CI, 28% to 39%) for SD, IH, and HD, respectively (P = .02). Patients receiving IH-TBI had a 25% higher risk of NRM compared with those receiving SD-TBI (12 Gy) (P = .007). Corresponding cumulative incidences of relapse were 36% (95% CI, 34% to 38%), 32% (95% CI, 29% to 36%), and 26% (95% CI, 21% to 31%; P = .001). Hazard ratios for mortality compared with SD were 1.06 (95% CI, .94 to 1.19; P = .36) for IH and .89 (95% CI, .76 to 1.05; P = .17) for HD. The study demonstrates that despite improvements in supportive care, myeloablative conditioning using higher doses of TBI (with cyclophosphamide) leads to worse NRM and offers no survival benefit over SD, despite reducing disease relapse.

Volume

25

Issue

12

First Page

2398

Last Page

2407

ISSN

1523-6536

Disciplines

Medicine and Health Sciences

PubMedID

31473319

Department(s)

Department of Medicine, Lehigh Valley Topper Cancer Institute

Document Type

Article

Share

COinS