title: Feasibility of Proton Beam Therapy for Ocular Melanoma Using a Novel 3D Treatment Planning Technique.
abstract: OBJECTIVE
  We evaluated sparing of normal structures using 3-dimensional (3D) treatment planning for proton therapy of ocular melanomas.
  
  
  METHODS
  We evaluated 26 consecutive patients with choroidal melanomas on a prospective registry. Ophthalmologic work-up included fundoscopic photographs, fluorescein angiography, ultrasonographic evaluation of tumor dimensions, and magnetic resonance imaging of orbits. Three tantalum clips were placed as fiducial markers to confirm eye position for treatment. Macula, fovea, optic disc, optic nerve, ciliary body, lacrimal gland, lens, and gross tumor volume were contoured on treatment planning compute tomography scans. 3D treatment planning was performed using noncoplanar field arrangements. Patients were typically treated with 3 fields, with at least 95% of planning target volume receiving 50 GyRBE in 5 fractions.
  
  
  RESULTS
  Tumor stage was T1a in 10 patients, T2a in 10 patients, T2b in 1 patient, T3a in 2 patients, T3b in 1 patient, and T4a in 2 patients. Acute toxicity was mild. All patients completed treatment as planned. Mean optic nerve dose was 10.1 Gy relative biological effectiveness (RBE). Ciliary body doses were higher for nasal (mean: 11.4 GyRBE) than temporal tumors (5.8 GyRBE). Median follow-up was 31 months (range: 18-40 months). Six patients developed changes which required intraocular bevacizumab or corticosteroid therapy, but only 1 patient developed neovascular glaucoma. Five patients have since died: 1 from metastatic disease and 4 from other causes. Two patients have since required enucleation: 1 due to tumor and 1 due to neovascular glaucoma.
  
  
  CONCLUSIONS
  3D treatment planning can be used to obtain appropriate coverage of choroidal melanomas. This technique is feasible with relatively low doses to anterior structures, and appears to have acceptable rates of local control with low risk of enucleation. Further evaluation and follow-up is needed to determine optimal dose-volume relationships for organs at risk to decrease complications rates.
authors.affiliation: Northwestern Medicine Chicago Proton Center, Warrenville, Illinois; Proton Collaborative Group. Electronic address: whartsell@chicagocancer.org.
authors.forename: William F
authors.initials: WF
authors.lastname: Hartsell
authors.affiliation: Retina Consultants, Des Plaines, Illinois.
authors.forename: Rashmi
authors.initials: R
authors.lastname: Kapur
authors.affiliation: Northwestern Medicine Chicago Proton Center, Warrenville, Illinois.
authors.forename: Siobhan O'Connor
authors.initials: SO
authors.lastname: Hartsell
authors.affiliation: Northwestern Medicine Chicago Proton Center, Warrenville, Illinois.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sweeney
authors.affiliation: Rush Medical College, Chicago, Illinois.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Lopes
authors.affiliation: Northwestern Medicine Chicago Proton Center, Warrenville, Illinois.
authors.forename: Amanda
authors.initials: A
authors.lastname: Duggal
authors.affiliation: Department of Ophthalmology, Rush University, Chicago, Illinois.
authors.forename: Jack
authors.initials: J
authors.lastname: Cohen
authors.affiliation: Northwestern Medicine Chicago Proton Center, Warrenville, Illinois; Proton Collaborative Group.
authors.forename: John
authors.initials: J
authors.lastname: Chang
authors.affiliation: Northwestern Medicine Central DuPage Hospital, Winfield, Illinois.
authors.forename: Rajeev S
authors.initials: RS
authors.lastname: Polasani
authors.affiliation: Proton Collaborative Group.
authors.forename: Megan
authors.initials: M
authors.lastname: Dunn
authors.affiliation: Northwestern Medicine Chicago Proton Center, Warrenville, Illinois; Proton Collaborative Group.
authors.forename: Mark
authors.initials: M
authors.lastname: Pankuch
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002830:Choroid Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D015353:Eye Enucleation; D005240:Feasibility Studies; D005260:Female; D057918:Fiducial Markers; D005500:Follow-Up Studies; D015355:Glaucoma, Neovascular / Q000517:prevention & control; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D009898:Optic Disk / Q000528:radiation effects; D059351:Organ Sparing Treatments / Q000379:methods*; D058958:Organs at Risk / Q000528:radiation effects; D061766:Proton Therapy / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012062:Relative Biological Effectiveness; D013997:Time Factors; D014792:Visual Acuity / Q000528:radiation effects