• Int. J. Radiat. Oncol. Biol. Phys. · Sep 2012

    Comparative Study

    Do we need daily image-guided radiotherapy by megavoltage computed tomography in head and neck helical tomotherapy? The actual delivered dose to the spinal cord.

    • Marciana Nona Duma, Severin Kampfer, Tibor Schuster, Nandana Aswathanarayana, Laura-Sophie Fromm, Michael Molls, Nicolaus Andratschke, and Hans Geinitz.
    • Department of Radiation Oncology, Technische Universität München, Klinikum rechts der Isar, München, Germany. Marciana.Duma@lrz.tumuenchen.de
    • Int. J. Radiat. Oncol. Biol. Phys. 2012 Sep 1; 84 (1): 283-8.

    PurposeTo quantify the actual delivered dose to the cervical spinal cord with different image-guided radiotherapy (IGRT) approaches during head and neck (HN) cancer helical tomotherapy.Methods And MaterialsTwenty HN patients (HNpts) treated with bilateral nodal irradiation were analyzed. Daily megavoltage computed tomography MVCT) scans were performed for setup purposes. The maximum dose on the planning CT scan (plan-Dmax) and the magnitude and localization of the actual delivered Dmax (a-Dmax) were analyzed for four scenarios: daily image-guided radiotherapy (dIGRT), twice weekly IGRT (2×WkIGRT), once weekly IGRT (1×WkIGRT), and no IGRT at all (non-IGRT). The spinal cord was recontoured on 236 MVCTs for each scenario (total, 944 fractions), and the delivered dose was recalculated for each fraction (fx) separately.ResultsFifty-one percent of the analyzed fx for dIGRT, 56% of the analyzed fx for the 2×WkIGRT, 62% of the analyzed fx for the 1×WkIGRT, and 63% of the analyzed fx for the non-IGRT scenarios received a higher a-Dmax than the plan-Dmax. The median increase of dose in these fx was 3.3% more for dIGRT, 5.8% more for 2×WkIGRT, 10.0% more for 1×WkIGRT, and 9.5% more for non-IGRT than the plan-Dmax. The median spinal cord volumes receiving a higher dose than the plan-Dmax were 0.02 cm³ for dIGRT, 0.11 cm³ for 2×WkIGRT, 0.31 cm³ for 1×WkIGRT, and 0.22 cm³ for non-IGRT. Differences between the dIGRT and all other scenarios were statistically significant (p < 0.05).ConclusionsCompared to the Dmax of the initial plan, daily IGRT had the smallest increase in dose. Furthermore, daily IGRT had the lowest proportion of fractions and the smallest volumes affected by a dose that was higher than the planned dose. For patients treated with doses close to the tolerance dose of the spinal cord, we recommend daily IGRT. For all other cases, twice weekly IGRT is sufficient.Copyright © 2012 Elsevier Inc. All rights reserved.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…

Want more great medical articles?

Keep up to date with a free trial of metajournal, personalized for your practice.
1,694,794 articles already indexed!

We guarantee your privacy. Your email address will not be shared.