title: Chromosomal aberration in peripheral lymphocytes and doses to the active bone marrow in radiotherapy of prostate cancer.
abstract: OBJECTIVE
  Radiotherapy plays an important role in the management of prostate cancer. Epidemiological data indicate a small but significant risk of radiation-induced leukemia after radiotherapy which might be related to the high mean bone marrow dose associated with radiotherapy of prostate cancer. The purpose of the study was to investigate the relation between the mean bone marrow dose and unstable chromosome aberrations in peripheral blood lymphocytes in patients undergoing conformal radiotherapy for prostate cancer as a possible indicator of risk. Endometrial cancer patients were also included for comparison.
  
  
  METHODS
  Nine patients, six with prostate cancer (60-73 years old) and three with endometrial cancer (61-81 years old) treated with radiotherapy were included in the study. The non-bony spaces inside the pelvic bones were outlined on every CT slice using the treatment planning system and mean doses to the bone marrow calculated. Blood samples of the patients were obtained at different times before, during and at the end of treatment. Lymphocytes were cultured in the usual way and metaphases scored for dicentric aberrations.
  
  
  RESULTS
  46 samples from nine patients were obtained. The mean number of metaphases analyzed per sample was 180 with a range from 52 to 435. The mean bone marrow doses for prostate cancer patients ranged from 2.8 to 4.2 Gy and for endometrial cancer patients from 12.8 to 14.8 Gy. The aberration yield increased with the planning target volume and the mean bone marrow dose.
  
  
  CONCLUSIONS
  The yield of dicentric aberrations for prostate cancer patients correlated closely with the mean bone marrow dose albeit the induction of dicentrics occurred in mature T lymphocytes most of which were probably in transit through the irradiated volumes. Therefore, the observed relationship between dicentrics and mean bone marrow doses are indirect.
authors.affiliation: Department of Radiotherapy, Hematology-Oncology Clinic, Clinicum of the University of Tartu, Estonia.
authors.forename: Eduard
authors.initials: E
authors.lastname: Gershkevitsh
authors.forename: Guido
authors.initials: G
authors.lastname: Hildebrandt
authors.forename: Ulrich
authors.initials: U
authors.lastname: Wolf
authors.forename: Friedrich
authors.initials: F
authors.lastname: Kamprad
authors.forename: Enn
authors.initials: E
authors.lastname: Realo
authors.forename: Klaus-Rüdiger
authors.initials: KR
authors.lastname: Trott
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000528:radiation effects*; D001918:Brachytherapy; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D020732:Cytogenetic Analysis; D016889:Endometrial Neoplasms / Q000532:radiotherapy; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects* / Q000648:ultrastructure; D008297:Male; D008677:Metaphase; D008875:Middle Aged; D010315:Particle Accelerators; D016012:Poisson Distribution; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011829:Radiation Dosage; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects; D012307:Risk Factors; D012984:Software