TITLE:
Complications from Plaque versus Proton Beam Therapy for Choroidal Melanoma: A Qualitative Systematic Review
AUTHORS:
Victoria L. Tseng, Anne L. Coleman, Zuo-Feng Zhang, Tara A. McCannel
KEYWORDS:
Choroidal Melanoma, Uveal Melanoma, Plaque Therapy, Brachytherapy, Proton Therapy, Treatment Complications, Metastasis, Enucleation
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.7 No.3,
March
10,
2016
ABSTRACT: Plaque
brachytherapy has been a mainstay of treatment for choroidal melanoma to
achieve intraocular tumor control. The most common radioisotopes used for
treating smaller sized tumors are Iodine-125 in North America and Ruthenium-106
in Europe. Proton beam radiotherapy is available at a few centers and may also
be used to achieve local tumor control. Both plaque and proton beam therapy are
known to be associated with a range of complications that may affect visual
outcome and quality of life. These include radiation retinopathy, optic
neuropathy, neovascular glaucoma and local treatment failure, requiring
enucleation. While differences in the rates of these complications have not been
well established in the literature for patients treated with plaque versus
proton beam therapy for choroidal melanoma, certain geographic regions prefer
one treatment modality over the other. The purpose of this qualitative
systematic review was to compare and contrast reported complications that
developed with plaque and proton beam therapy for the treatment of choroidal
melanoma in studies published over a ten-year period. Reported rates suggest
that patients with proton beam therapy had potentially higher rates of
complications, including vision loss, enucleation, and neovascular glaucoma
compared to those with plaque therapy. The rates of optic neuropathy, radiation
retinopathy, and cataract formation were widely variable for the two treatment
modalities and rates of metastasis and metastasis-free survival appeared
similar with both treatments. The most common reported predictors of ocular
complications following both types of therapy were tumor distance from the
optic nerve, tumor thickness, and radiation dose, suggesting that inherent
tumor characteristics play a role in visual prognosis.