title: Effect of fractionated regional external beam radiotherapy on peripheral blood cell count.
abstract: OBJECTIVE
  The purpose of this study was to assess the need for obtaining weekly complete blood count (CBC) values and to identify the pattern of changes in CBC during regional conventional fractionated radiotherapy.
  
  
  METHODS
  A retrospective analysis of CBC data on 299 adult cancer patients who received definitive conventional radiotherapy to head and neck (n = 95), chest (n = 96), and pelvis (n = 108) was performed. Temporal patterns and magnitude of change in white blood cells, neutrophils, lymphocytes, and platelets during radiotherapy were examined.
  
  
  RESULTS
  There were statistically significant declines in all counts, albeit not clinically significant. Notable differences between disease sites were found. The greatest weekly interval change in counts occurred during the first week of radiotherapy for all groups of patients. The mean WBC nadir values during treatment were 5.8 for head & neck, 6.8 for chest, and 5.4 for pelvis. The nadirs for all counts occurred toward the middle-to-end of radiotherapy. Lymphocytes were found to be more sensitive to radiotherapy than other leukocyte subcomponents.
  
  
  CONCLUSIONS
  Our study suggests that weekly CBC monitoring is not necessary for all patients undergoing standard fractionated radiotherapy. Baseline blood counts may be used to determine an optimal schedule for monitoring CBCs in patients receiving conventional radiation alone. Reduced monitoring of CBC may result in significant financial savings.
authors.affiliation: James A. Haley Veterans Administration Hospital, Tampa, FL, USA. zacharb@moffitt.usf.edu
authors.forename: B
authors.initials: B
authors.lastname: Zachariah
authors.forename: S S
authors.initials: SS
authors.lastname: Jacob
authors.forename: C
authors.initials: C
authors.lastname: Gwede
authors.forename: A
authors.initials: A
authors.lastname: Cantor
authors.forename: J
authors.initials: J
authors.lastname: Patil
authors.forename: L
authors.initials: L
authors.lastname: Casey
authors.forename: A B
authors.initials: AB
authors.lastname: Zachariah
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000166:cytology / Q000528:radiation effects*; D019583:Dose Fractionation, Radiation; D006801:Humans; D007958:Leukocyte Count; D008214:Lymphocytes / Q000166:cytology / Q000528:radiation effects*; D009369:Neoplasms / Q000097:blood* / Q000532:radiotherapy*; D009504:Neutrophils / Q000166:cytology / Q000528:radiation effects*; D010976:Platelet Count; D012189:Retrospective Studies