title: 103Pd versus125I ophthalmic plaque brachytherapy: preoperative comparative radiation dosimetry for 319 uveal melanomas.
abstract: OBJECTIVE
  This study was conducted to compare the relative, clinical intraocular dose distribution for palladium-103 (103Pd) versus iodine-125 (125I) ophthalmic plaque radiation therapy.
  
  
  METHODS
  Preoperative comparative radiation dosimetry was performed to evaluate 319 consecutive uveal melanomas treated between 2006 and 2012.
  
  
  RESULTS
  There were 68 (21.3 %) anterior (iris and/or ciliary body) and 251 (78.7 %) choroidal melanomas examined in this study. According to AJCC staging, 7th edition, 146 (45.8 %) were T1, 126 (39.5 %) T2, 40 (12.5 %) T3, and 7 (2.2 %) T4. All were prescribed an equivalent tumor-apex dose. When compared to125I,103Pd was associated with a mean 41.9 % lower radiation dose to the opposite eye wall (p< 0.001), 12.7 % to the lens center (p< 0.001), 7.5 % to the optic disc (p= 0.008), and a 3.8 % decrease to the fovea (p= 0.034). However, subgroup analysis of smaller (T1-staged) tumors showed greater dose reductions to normal ocular structures compared to larger (T4-staged) tumors. Tumor and therefore plaque location also affected intraocular dose distribution. For example, palladium-103-related dose reductions to the fovea, optic nerve, and opposite eye wall were significantly greater for iris and ciliary body tumors compared to posterior choroidal melanomas (p< 0.001). After comparative dosimetry, 98.7 % (n= 315/319) were treated with103Pd.
  
  
  CONCLUSIONS
  Preoperative comparative radiation dosimetry was performed for a large cohort of patients with uveal melanoma. It influenced radionuclide selection, offered an opportunity for radiation sparing of critical vision-related intraocular structures, and typically increased radiation within the tumors.
authors.affiliation: The New York Eye Cancer Center, 115 East 61st Street, New York City, NY 10065 USA ; Mt. Sinai Beth Israel Cancer Center, New York City, NY USA ; The New York Eye and Ear Infirmary of Mt. Sinai, New York City, NY USA ; New York University School of Medicine, New York City, NY USA.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Finger
authors.affiliation: The New York Eye Cancer Center, 115 East 61st Street, New York City, NY 10065 USA ; New York University School of Medicine, New York City, NY USA.
authors.forename: Di
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Mt. Sinai Beth Israel Cancer Center, New York City, NY USA.
authors.forename: Nina
authors.initials: N
authors.lastname: Kalach
authors.affiliation: The New York Eye Cancer Center, 115 East 61st Street, New York City, NY 10065 USA ; The New York Eye and Ear Infirmary of Mt. Sinai, New York City, NY USA.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Semenova
authors.affiliation: Mt. Sinai Beth Israel Cancer Center, New York City, NY USA ; The New York Eye and Ear Infirmary of Mt. Sinai, New York City, NY USA.
authors.forename: Walter
authors.initials: W
authors.lastname: Choi
keywords: Brachytherapy; Choroidal melanoma; Iodine-125; Palladium-103; Plaque