Risk factors for radiation-induced optic neuropathy: a case-control study.
OBJECTIVE
Identifying risk factors for radiation-induced optic neuropathy (RION) could promote a more conservative approach to radiation treatment planning in vulnerable patients.


BACKGROUND
This study explored possible factors beyond radiation dose associated with the development of RION after external beam radiation therapy.


METHODS
This was a retrospective case-control study conducted at a university hospital tertiary care center.


METHODS
Cases (n = 14) meeting criteria for a diagnosis of RION by neuro-ophthalmologic exam were identified from a single-centre neuro-ophthalmology database. Controls (n = 31) without RION were selected from a single-centre radiation oncology database.


METHODS
Controls were matched to cases based upon maximum radiation dose to the optic apparatus. Patient characteristics and treatment parameters were interrogated by univariate analysis for attributes predisposing to RION.


METHODS
The primary parameter was a significant association of patient characteristics or treatment parameters with RION.


RESULTS
Controlling for radiation dosage, no significant associations for alternative risk factors were identified.


CONCLUSIONS
These results support the literature suggesting that the primary risk factor for developing RION is radiation dosage and that additional patient-related and tumour-related risk factors may play only a minor role.
Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, Missouri, USA.
Ian
I
Ferguson
Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, Missouri, USA.
Julie
J
Huecker
Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri, USA.
Jiayi
J
Huang
Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, USA.
Collin
C
McClelland
Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, Missouri, USA.
Gregory
G
Van Stavern
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008923:Missouri / Q000453:epidemiology; D009369:Neoplasms / Q000532:radiotherapy*; D009900:Optic Nerve / Q000473:pathology / Q000528:radiation effects*; D009901:Optic Nerve Diseases / Q000453:epidemiology / Q000209:etiology*; D011832:Radiation Injuries / Q000150:complications* / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
optic nerve diseases; optic neuropathy; radiation injury