title: Low-dose cranial boost in high-risk adult acute lymphoblastic leukemia patients undergoing bone marrow transplant.
abstract: OBJECTIVE
  Acute lymphoblastic leukemia (ALL) has a predilection for CNS involvement. Patients with high-risk ALL are often managed with transplant using a radiation-based conditioning regimen. Historically, a high-dose prophylactic cranial boost (CB) of ≥12 Gy was given to reduce risk of central nervous system (CNS) recurrence. However, the use of CB has fallen out of favor because of toxicity concerns. In high-risk adults undergoing transplant at our institution, we have used a low-dose 6 Gy CB to reduce toxicity while conditioning adults with fully developed brains. The safety, efficacy, and utility of a low-dose CB in adults are poorly studied; herein, we report their outcomes and toxicity.
  
  
  METHODS
  We identified all high-risk ALL patients undergoing total body irradiation as part of their conditioning regimen. Those who received 6 Gy CB or no CB were included (55 total). Their charts were reviewed and statistical analyses were completed with R, version 2.15.2.
  
  
  RESULTS
  In patients undergoing CB, 3-year CNS disease-free survival and overall survival were 94.7% and 62.7%. In those not undergoing CBs, survivals were 81.8% and 51.5%. Notably, within the CB cohort, patients without prior CNS involvement had no CNS failures. In contrast, in the non-CB cohort, there were 2 CNS failures in patients with no history of CNS involvement. In the CB cohort, the only notable acute toxicity was parotitis (2.8%). Late toxicity in the CB cohort included 1 instance of cataracts (2.8%) without any evidence of cognitive impairment or potential radiation induced secondary malignancy.
  
  
  CONCLUSIONS
  A dose of 6 Gy CB is well-tolerated in the adult ALL population as part of a radiation-based conditioning regimen. Low-dose CB may be considered in adult patients with high-risk ALL without prior CNS involvement to reduce the likelihood of recurrence.
authors.affiliation: Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: William
authors.initials: W
authors.lastname: Su
authors.affiliation: Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Marcher
authors.initials: M
authors.lastname: Thompson
authors.affiliation: Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Ren-Dih
authors.initials: RD
authors.lastname: Sheu
authors.affiliation: Department of Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Amir
authors.initials: A
authors.lastname: Steinberg
authors.affiliation: Department of Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Luis
authors.initials: L
authors.lastname: Isola
authors.affiliation: Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Richard
authors.initials: R
authors.lastname: Stock
authors.affiliation: Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, New York, New York. Electronic address: Richard.Bakst@mountsinai.org.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Bakst
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols; D016026:Bone Marrow Transplantation; D002490:Central Nervous System / Q000528:radiation effects; D016543:Central Nervous System Neoplasms / Q000517:prevention & control*; D003131:Combined Modality Therapy / Q000379:methods; D016371:Cranial Irradiation / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000532:radiotherapy* / Q000601:surgery*; D011829:Radiation Dosage; D012189:Retrospective Studies; D019172:Transplantation Conditioning / Q000379:methods*; D016896:Treatment Outcome; D014916:Whole-Body Irradiation / Q000009:adverse effects / Q000379:methods; D055815:Young Adult