Partial volume tolerance of the spinal cord and complications of single-dose radiosurgery

Samuel Ryu, Jian Yue Jin, Ryan Jin, Jack Rock, Munther Ajlouni, Benjamin Movsas, Mark Rosenblum, Jae Ho Kim

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177 Scopus citations

Abstract

BACKGROUND. Spine radiosurgery causes a rapid dose fall-off within the spinal cord. The tolerance of partial volume of the spinal cord may determine the extent of clinical application. The study analyzed the partial volume tolerance of the human spinal cord to single fraction radiosurgery. METHODS. A total of 230 lesions with spine metastases in 177 patients were treated with radiosurgery with single fraction of 8 to 18 Gy, prescribed to the 90% isodose line that encompassed the target volume. Spinal cord volume was defined as 6 mm above and below the radiosurgery target volume. Spinal cord dose was calculated from the radiation dose/spinal cord volume histogram and correlated with clinical/neurological status and radiographic studies. Median follow-up was 6.4 months (range, 0.5-49 months). The 1-year survival rate was 49%. RESULTS. The average spinal cord volume defined at the treated spinal segment was 5.9 ± 2.2 mL. The average dose to the 10% spinal cord volume was 9.8 ± 1.5 Gy, calculated from the dose-volume histogram in the group of 18 Gy prescribed dose. The spinal cord volume that received higher than 80% of the prescribed dose was 0.07 ± 0.10 mL, which represented 1.3 ± 1.8% of the cord volume. Among the 86 patients who survived longer than 1 year there was 1 case of radiation-induced cord injury after 13 months of radiosurgery. There were no other cases of spinal cord sequelae. CONCLUSIONS. Whereas the maximum spinal cord tolerance to single-dose radiation is not known, partial volume tolerance of the human spinal cord is at least 10 Gy to 10% of the spinal cord volume defined as 6 mm above and below the radiosurgery target.

Original languageEnglish (US)
Pages (from-to)628-636
Number of pages9
JournalCancer
Volume109
Issue number3
DOIs
Publication statusPublished - Feb 1 2007

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Keywords

  • Partial volume tolerance
  • Spinal cord tolerance
  • Spine metastasis
  • Spine radiosurgery

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this

Ryu, S., Jin, J. Y., Jin, R., Rock, J., Ajlouni, M., Movsas, B., ... Kim, J. H. (2007). Partial volume tolerance of the spinal cord and complications of single-dose radiosurgery. Cancer, 109(3), 628-636. https://doi.org/10.1002/cncr.22442