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Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors.

Publication ,  Journal Article
Khoo, VS; Oldham, M; Adams, EJ; Bedford, JL; Webb, S; Brada, M
Published in: Int J Radiat Oncol Biol Phys
September 1, 1999

PURPOSE: Intensity-modulated radiotherapy (IMRT) offers the potential to more closely conform dose distributions to the target, and spare organs at risk (OAR). Its clinical value is still being defined. The present study aims to compare IMRT with stereotactically guided conformal radiotherapy (SCRT) for patients with medium size convex-shaped brain tumors. METHODS AND MATERIALS: Five patients planned with SCRT were replanned with the IMRT-tomotherapy method using the Peacock system (Nomos Corporation). The planning target volume (PTV) and relevant OAR were assessed, and compared relative to SCRT plans using dose statistics, dose-volume histograms (DVH), and the Radiation Therapy Oncology Group (RTOG) stereotactic radiosurgery criteria. RESULTS: The median and mean PTV were 78 cm3 and 85 cm3 respectively (range 62-119 cm3). The differences in PTV doses for the whole group (Peacock-SCRT +/-1 SD) were 2%+/-1.8 (minimum PTV), and 0.1%+/-1.9 (maximum PTV). The PTV homogeneity achieved by Peacock was 12.1%+/-1.7 compared to 13.9%+/-1.3 with SCRT. Using RTOG guidelines, Peacock plans provided acceptable PTV coverage for all 5/5 plans compared to minor coverage deviations in 4/5 SCRT plans; acceptable homogeneity index for both plans (Peacock = 1.1 vs. SCRT = 1.2); and comparable conformity index (1.4 each). As a consequence of the transaxial method of arc delivery, the optic nerves received mean and maximum doses that were 11.1 to 11.6%, and 10.3 to 15.2% higher respectively with Peacock plan. The maximum optic lens, and brainstem dose were 3.1 to 4.8% higher, and 0.6% lower respectively with Peacock plan. However, all doses remained below the tolerance threshold (5 Gy for lens, and 50 Gy for optic nerves) and were clinically acceptable. CONCLUSIONS: The Peacock method provided improved PTV coverage, albeit small, in this group of convex tumors. Although the OAR doses were higher using the Peacock plans, all doses remained within the clinically defined threshold and were clinically acceptable. Further improvements may be expected using other methods of IMRT planning that do not limit the treatment delivery to transaxial arcs. Each IMRT system needs to be individually assessed as the paradigm utilized may provide different outcomes.

Duke Scholars

Published In

Int J Radiat Oncol Biol Phys

DOI

ISSN

0360-3016

Publication Date

September 1, 1999

Volume

45

Issue

2

Start / End Page

415 / 425

Location

United States

Related Subject Headings

  • Radiotherapy, Conformal
  • Radiotherapy Planning, Computer-Assisted
  • Radiosurgery
  • Optic Chiasm
  • Oncology & Carcinogenesis
  • Meningioma
  • Meningeal Neoplasms
  • Humans
  • Glioma
  • Cranial Nerve Neoplasms
 

Citation

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Khoo, V. S., Oldham, M., Adams, E. J., Bedford, J. L., Webb, S., & Brada, M. (1999). Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors. Int J Radiat Oncol Biol Phys, 45(2), 415–425. https://doi.org/10.1016/s0360-3016(99)00213-8
Khoo, V. S., M. Oldham, E. J. Adams, J. L. Bedford, S. Webb, and M. Brada. “Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors.Int J Radiat Oncol Biol Phys 45, no. 2 (September 1, 1999): 415–25. https://doi.org/10.1016/s0360-3016(99)00213-8.
Khoo VS, Oldham M, Adams EJ, Bedford JL, Webb S, Brada M. Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors. Int J Radiat Oncol Biol Phys. 1999 Sep 1;45(2):415–25.
Khoo, V. S., et al. “Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors.Int J Radiat Oncol Biol Phys, vol. 45, no. 2, Sept. 1999, pp. 415–25. Pubmed, doi:10.1016/s0360-3016(99)00213-8.
Khoo VS, Oldham M, Adams EJ, Bedford JL, Webb S, Brada M. Comparison of intensity-modulated tomotherapy with stereotactically guided conformal radiotherapy for brain tumors. Int J Radiat Oncol Biol Phys. 1999 Sep 1;45(2):415–425.
Journal cover image

Published In

Int J Radiat Oncol Biol Phys

DOI

ISSN

0360-3016

Publication Date

September 1, 1999

Volume

45

Issue

2

Start / End Page

415 / 425

Location

United States

Related Subject Headings

  • Radiotherapy, Conformal
  • Radiotherapy Planning, Computer-Assisted
  • Radiosurgery
  • Optic Chiasm
  • Oncology & Carcinogenesis
  • Meningioma
  • Meningeal Neoplasms
  • Humans
  • Glioma
  • Cranial Nerve Neoplasms