Heterogeneity in tumor microvascular response to radiation

M. W. Dewhirst, R. Oliver, C. Y. Tso, C. Gustafson, Timothy W Secomb, J. F. Gross

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

Viable hypoxic cells have reduced radiosensitivity and could be a potential cause for treatment failure with radiotherapy. The process of reoxygenation, which may occur after radiation exposure, could increase the probability for control. However, incomplete or insufficient reoxygenation may still be a potential cause for local treatment failure. One mechanism that has been thought to be responsible for reoxygenation is an increase in vascular prominence after radiation. However, the effect is known to be heterogeneous. In this study, tumor microvascular hemodynamics and morphologies were studied using the R3230 Ac mammary adenocarcinoma transplanted in a dorsal flap window chamber of the Fisher-344 rat. Measurements were made before and after (at 24 and 72 hr) 5-Gy radiation exposure to assess microvascular changes and to explore possible explanations for the heterogeneity of the effect. There was considerable heterogeneity between tumors prior to radiation. Vascular densities ranged from 67 to 3000 vessels/mm3 and median vessel diameters from 22 to 85 μm. Pretreatment perfusion values varied by a factor of six. In irradiated tumors, conjoint increases in both vascular density and perfusion occurred in most tumors, although the degree of change was variable from one individual to the next. The degree of change in density was inversely related to median pretreatment diameter. Relative change in flow, as predicted by morphometric measurements, overestimated observed changes in flow measured hemodynamically. These results support that heterogeneity in tumor vascular effects from radiation are somewhat dependent on pretreatment morphology as well as relative change in morphology. Since changes in flow could not be completely explained by morphometric measurements, however, it is likely that radiation induced changes in pressure and/or viscosity contribute to the overall effect. Further work in this laboratory will investigate these hypotheses.

Original languageEnglish (US)
Pages (from-to)559-568
Number of pages10
JournalInternational Journal of Radiation Oncology Biology Physics
Volume18
Issue number3
DOIs
StatePublished - 1990

Fingerprint

tumors
Blood Vessels
Radiation
pretreatment
radiation
radiation dosage
Neoplasms
Treatment Failure
vessels
Perfusion
Radiation Dosage
hemodynamics
causes
Radiation Tolerance
Radiation Effects
radiation tolerance
Viscosity
rats
radiation therapy
Adenocarcinoma

Keywords

  • Heterogeneity
  • Hypoxia
  • Microcirculation
  • Reoxygenation

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Radiation

Cite this

Heterogeneity in tumor microvascular response to radiation. / Dewhirst, M. W.; Oliver, R.; Tso, C. Y.; Gustafson, C.; Secomb, Timothy W; Gross, J. F.

In: International Journal of Radiation Oncology Biology Physics, Vol. 18, No. 3, 1990, p. 559-568.

Research output: Contribution to journalArticle

Dewhirst, M. W. ; Oliver, R. ; Tso, C. Y. ; Gustafson, C. ; Secomb, Timothy W ; Gross, J. F. / Heterogeneity in tumor microvascular response to radiation. In: International Journal of Radiation Oncology Biology Physics. 1990 ; Vol. 18, No. 3. pp. 559-568.
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