Hartel C, Nasonova E, Fuss MC, Nikoghosyan AV, Debus J, Ritter S. Persistence of radiation-induced aberrations in patients after radiotherapy with C-ions and IMRT.
Clin Transl Radiat Oncol 2018;
13:57-63. [PMID:
30364751 PMCID:
PMC6198102 DOI:
10.1016/j.ctro.2018.10.002]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/02/2018] [Accepted: 10/08/2018] [Indexed: 11/29/2022] Open
Abstract
A follow-up of aberrations in lymphocytes of cancer patients was performed.
The ratio of dicentrics to translocations declined indicating bone marrow damage.
Bone marrow exposure was verified by examination of treatment plans.
Clonal aberrations were also present before therapy and thus not radiation induced.
Background and purpose
Chromosomal aberrations in peripheral blood lymphocytes are a biomarker for radiation exposure and are associated with an increased risk for malignancies. To determine the long-term cytogenetic effect of radiotherapy, we analyzed the persistence of different aberration types up to 2.5 years after the treatment.
Materials and methods
Cytogenetic damage was analyzed in lymphocytes from 14 patients that had undergone C-ion boost + IMRT treatment for prostate cancer. Samples were taken immediately, 1 year and 2.5 years after therapy. Aberrations were scored using the multiplex fluorescence in situ hybridization technique and grouped according to their transmissibility to daughter cells.
Results
Dicentric chromosomes (non-transmissible) and translocations (transmissible) were induced with equal frequencies. In the follow-up period, the translocation yield remained unchanged while the yield of dicentrics decreased to ≈40% of the initial value (p = 0.011 and p = 0.001 for 1 and 2.5 years after compared to end of therapy). In 2 patients clonal aberrations were observed; however they were also found in samples taken before therapy and thus were not radiotherapy induced.
Conclusion
The shift in the aberrations spectrum towards a higher fraction of translocations indicates the exposure of hematopoietic stem and progenitor cells underlining the importance of a careful sparing of bone marrow during radiotherapy to minimize the risk for secondary cancers.
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