Phase 1/2 trial of total marrow and lymph node irradiation to augment reduced-intensity transplantation for advanced hematologic malignancies

Abstract

This phase 1/2 study assessed the augmentation of reduced-intensity conditioning (RIC) with total marrow and lymph node irradiation (TMLI), for peripheral blood stem cell transplantation, in patients with advanced hematologic disease. The regimen consisted of fludarabine 25 mg/m(2) per day for 5 days, melphalan 140 mg/m(2) for one day, and TMLI radiation at 150 cGy/fraction in 8 fractions over 4 days. Eligible patients were over 50 years old and/or had compromised organ function. Median age of the 33 evaluable patients was 55.2 years. Eighteen events of nonhematologic grade III or higher toxicities occurred in 9 patients. Day 30 and day 100 mortalities were 3% and 15%, respectively. Patients achieved myeloid and platelet engraftment at a median of 14 days after transplantation. Long-term toxicities occurred in 2 patients: hypokalemia and tremor, both grade III, on days 370 and 361 after transplantation. Fourteen patients died, 7 of relapse-related causes and 7 of non-relapse-related causes. With a median follow-up for living patients of 14.7 months, 1-year overall survival, event-free survival, and non-relapse-related mortality were 75%, 65%, and 19%, respectively. Addition of TMLI to RIC is feasible and safe and could be offered to patients with advanced hematologic malignancies who might not otherwise be candidates for RIC.

Figure 1

TMLI isodose distribution shows the colorwash isodose distribution of a patient receiving 12 Gy TMLI. Representative sagittal, coronal, and axial planes. Isodose distributions for 12, 10, 8, and 6 Gy are shown.

Figure 2

Survival outcome curves show OS (solid line) and EFS (hyphenated line) in months, calculated as Kaplan-Meier estimates.

Figure 3

Cumulative incidence of NRM and relapse as competing risks shows both cumulative incidence of relapse (hyphenated line) and NRM (solid line).