title: Graft-versus-host disease after radiation therapy in patients who have undergone allogeneic stem cell transplantation: two case reports.
abstract: BACKGROUND
  Patients who undergo allogeneic stem cell transplantation and subsequent radiation therapy uncommonly develop graft-versus-host disease within the irradiated area. We quantified the incidence of this complication, which is a novel contribution to the field. From 2010 to 2014, 1849 patients underwent allogeneic stem cell transplantation, and 41 (2 %) received radiation therapy afterward. Of these, two patients (5 %) developed graft-versus-host disease within the irradiated tissues during or immediately after radiation therapy.
  
  
  METHODS
  The first patient is a 37-year-old white man who had Hodgkin lymphoma; he underwent allogeneic stem cell transplantation from a matched unrelated donor and received radiation therapy for an abdominal and pelvic nodal recurrence. After 28.8 Gy, he developed grade 4 gastrointestinal graft-versus-host disease, refractory to tacrolimus and steroids, but responsive to pentostatin and photopheresis. The other patient is a 24-year-old white man who had acute leukemia; he underwent allogeneic stem cell transplantation from a matched related donor and received craniospinal irradiation for a central nervous system relapse. After 24 cobalt Gy equivalent, he developed severe cutaneous graft-versus-host disease, sharply delineated within the radiation therapy field, which was responsive to tacrolimus and methylprednisolone.
  
  
  CONCLUSIONS
  We conclude that graft-versus-host disease within irradiated tissues is an uncommon but potentially serious complication that may follow radiation therapy in patients who have undergone allogeneic stem cell transplantation. Clinicians must be aware of this complication and prepared with strategies to mitigate risk. Patients who have undergone allogeneic stem cell transplantation represent a unique population that may offer novel insight into the pathways involved in radiation-related inflammation.
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA. samilgrom@mdanderson.org.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Milgrom
authors.affiliation: Department of Stem Cell Transplantation, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: Yago
authors.initials: Y
authors.lastname: Nieto
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: Chelsea C
authors.initials: CC
authors.lastname: Pinnix
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: Grace L
authors.initials: GL
authors.lastname: Smith
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: Christine F
authors.initials: CF
authors.lastname: Wogan
authors.affiliation: Department of Stem Cell Transplantation, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Rondon
authors.affiliation: Department of Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.affiliation: Department of Stem Cell Transplantation, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: Partow
authors.initials: P
authors.lastname: Kebriaei
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas, USA.
authors.forename: Bouthaina S
authors.initials: BS
authors.lastname: Dabaja
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D017809:Fatal Outcome; D006086:Graft vs Host Disease / Q000209:etiology* / Q000628:therapy; D018380:Hematopoietic Stem Cell Transplantation; D006689:Hodgkin Disease / Q000532:radiotherapy* / Q000601:surgery*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015456:Leukemia, Biphenotypic, Acute / Q000532:radiotherapy* / Q000601:surgery*; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use; D015649:Pentostatin / Q000627:therapeutic use; D017893:Photopheresis; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D016559:Tacrolimus / Q000627:therapeutic use; D014184:Transplantation, Homologous; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D000970:Antineoplastic Agents; D007166:Immunosuppressive Agents; D015649:Pentostatin; D016559:Tacrolimus; D008775:Methylprednisolone
keywords: Allogeneic stem cell transplant; GVHD; Graft-versus-host disease; RT; Radiation therapy