Proton or stereotactic photon irradiation for posterior uveal melanoma? A planning intercomparison.
OBJECTIVE
Proton and stereotactic radiotherapy with photons (SRT) are both used to treat choroidal melanomas in proximity to optic disk and fovea centralis, a situation where plaque therapy is prone to complications. A comparative treatment- planning study was done to assess the capability of both modalities to preserve vision.


METHODS
In ten patients treated with 68-MeV protons, SRT with 6-MV photons was planned. Structures most important for visual acuity (fovea and optic disk, optic nerve) were contoured identically for both therapies. Safety margins of 1.5 mm for proton therapy were reduced to 1.0 mm for SRT.


RESULTS
Proton-beam therapy was superior in eight of ten situations, and this result did not differ significantly by changes in the weighting of the different parameters analyzed.


CONCLUSIONS
When dose deposition to those structures most important for the preservation of vision is taken into account, under the conditions examined proton therapy offers an advantage in the majority of the patients evaluated.
Höcht
Stefan
S
Department of Radiooncology and Radiotherapy, Charité - University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany. stefan.hoecht@charite.de
Stark
Roland
R
Seiler
Frank
F
Heufelder
Jens
J
Bechrakis
Nikolaos E
NE
Cordini
Dino
D
Marnitz
Simone
S
Kluge
Heinz
H
Foerster
Michael H
MH
Hinkelbein
Wolfgang
W
D005131:Eye Injuries / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008545:Melanoma / Q000628:therapy*; D011379:Prognosis; D061766:Proton Therapy; D011522:Protons / Q000009:adverse effects; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D011874:Radiometry / Q000379:methods; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome; D014604:Uveal Neoplasms / Q000628:therapy*
D011522:Protons