• Neurosurgery · Oct 2014

    Dose-volume analysis of radiation-induced optic neuropathy after single-fraction stereotactic radiosurgery.

    • Bruce E Pollock, Michael J Link, Jacqueline A Leavitt, and Scott L Stafford.
    • *Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota; ‡Department of Radiation Oncology, Mayo Clinic College of Medicine, Rochester, Minnesota; §Department of Otorhinolaryngology-Head and Neck Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota; ¶Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, Minnesota.
    • Neurosurgery. 2014 Oct 1; 75 (4): 456-60; discussion 460.

    BackgroundThe risk of radiation-induced optic neuropathy (RION) is the primary limitation of single-fraction stereotactic radiosurgery (SRS) for many patients with parasellar lesions.ObjectiveTo define the normal tissue complication probability of the anterior visual pathways (AVPs) after single-fraction SRS.MethodsRetrospective review comparing visual function before and after SRS in 133 patients (266 sides) with pituitary adenomas having SRS between October 2007 and July 2012. Patients with prior radiation therapy or SRS were excluded. The median follow-up after SRS was 32 months.ResultsThe median maximum point dose to the AVP was 9.2 Gy (interquartile range [IQR], 6.9-10.8). One hundred seventy-four sides (65%) received >8 Gy: the median 8-Gy volume was 15.8 mm³ (IQR, 3.7-36.2). Ninety-four sides (35%) received >10 Gy; the median 10-Gy volume was 1.6 mm³ (IQR, 0.5-5.3). Twenty-nine sides (11%) received >12 Gy; the median 12-Gy volume was 0.1 mm³ (IQR, 0.1-0.6). No patient had a RION after SRS. The chances of developing a RION at the 8-Gy, 10-Gy, and 12-Gy volumes (95% confidence interval) in this series were 0% to 2.6%, 0% to 4.7%, and 0% to 13.9%, respectively.ConclusionThe AVP in patients without prior radiation treatments can safely receive radiation doses up to 12 Gy with a low risk of RION. Although additional studies are needed to better delineate the normal tissue complication probability of the AVP, adherence to the AVP radiation tolerance guidelines developed 20 years ago (8 Gy) limits the applicability and potentially the effectiveness of single-fraction SRS for patients with lesions in the parasellar region.

      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…