Posttreatment visual acuity in patients treated with episcleral plaque therapy for choroidal melanomas: dose and dose rate effects. Int J Radiat Oncol Biol Phys 2002 Mar 15;52(4):989-95
Date
04/18/2002Pubmed ID
11958893DOI
10.1016/s0360-3016(01)02723-7Scopus ID
2-s2.0-0037086331 (requires institutional sign-in at Scopus site) 45 CitationsAbstract
PURPOSE: To determine the relationship between the long-term visual function and the dose and dose rates delivered to critical ocular structures in patients with choroidal melanoma treated with 125I episcleral plaque radiotherapy.
MATERIALS AND METHODS: From 1987 to 1994, 63 patients underwent 125I episcleral plaque (Collaborative Ocular Melanoma Study [COMS] design) application for the treatment of choroidal melanoma. The mean tumor height was 4.5 mm (range 1.7-8.3). Doses and dose rates at the tumor apex, macula, and optic disc were calculated. Forty-three records were scored to assess whether a decrease in visual acuity of >2 lines on a standard Snellen eye chart had occurred. Patient age and the presence of hypertension or diabetes were noted. Statistical analysis was performed to assess both the rate at which visual decline had occurred and the presence of significant factors that had contributed to this decline.
RESULTS: With a median follow-up of 36 months, the 3-year actuarial survival rate was 93.6%. The 3-year actuarial local control rate was 86.9%. The median time to visual loss after therapy was 18.7 months. The 3-year actuarial rate of visual preservation was 40.5%. Multivariate analysis demonstrated higher macula dose rates (p = 0.003) to forecast visual decline. Macula dose rates of 111 +/- 11.1 cGy/h were associated with a 50% risk of significant visual loss.
CONCLUSION: Patients in our series treated with 125I plaque brachytherapy for choroidal melanoma experienced favorable tumor control, but with a measurable incidence of visual decline. Higher dose rates to the macula correlated strongly with poorer posttreatment visual outcome. This information may be valuable in selecting the optimal dose rates to treat choroidal melanomas and to predict the risk of visual decline.
Author List
Jones R, Gore E, Mieler W, Murray K, Gillin M, Albano K, Erickson BAuthors
Beth A. Erickson MD Professor in the Radiation Oncology department at Medical College of WisconsinElizabeth M. Gore MD Professor in the Radiation Oncology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdultAged
Aged, 80 and over
Analysis of Variance
Brachytherapy
Choroid Neoplasms
Female
Humans
Iodine Radioisotopes
Macula Lutea
Male
Melanoma
Middle Aged
Optic Disk
Survival Rate
Vision Disorders
Visual Acuity