|
|
Tolerance dose in gamma knife surgery of lesions
extending to the anterior visual pathway
Kenai H, Yamashita M, Nakamura T, Asano T, Sainoh M, Nagatomi H
Department of Neurosurgery, Nagatomi Neurosurgical Hospital, Oita, Japan.
ngkckenai@mb.neweb.ne.jp
Object. The authors performed a retrospective analysis of the radiation dose
to the anterior visual pathway (AVP) to assess its tolerance to gamma knife
surgery.
Methods. They examined five cases followed for more than 3 years.
The AVP was treated with 10-Gy doses or higher.
The mean maximum delivered
dose to the AVP was 14 Gy.
Ten gray or more was delivered to 25.5% of the
ipsilateral AVP, 12 Gy or more to 12.5% of the ipsilateral AVP, and 14 Gy or
more to 5.7% of the ipsilateral AVP.
Although the mean follow-up period was
40.8 months (36-51 months), no cases of visual function deterioration
developed.
Conclusions. The tolerance dose of the AVP is considered to be
less than 8 to 10 Gy; however, although the delivered dose to the AVP
definitely exceeded the tolerance dose in all five cases, no visual
disturbance has been identified.
Longer follow up is required before any
final conclusions may be drawn.
Nonetheless, it is suggested that a visual
disturbance may be avoided by using careful accurate dose planning even if
the dose delivered to the AVP is higher than currently believed to be
acceptable.
PMID: 15662816 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15662816
|
