Cataract development in patients treated with proton beam therapy for uveal melanoma.
OBJECTIVE
To evaluate the incidence, risk factors, and dosages of proton beam therapy associated with cataract development, and long-term visual outcomes after treatment of uveal melanoma.


METHODS
All patients receiving primary proton beam therapy for uveal melanoma between 1998 and 2008 with no signs of cataract before irradiation were included. A minimum follow-up of 12 months was determined. Exclusion criteria included all applied adjuvant therapies such as intravitreal injections, laser photocoagulation, tumor resections, or re-irradiation. For subgroup analysis, we included all patients who underwent brachytherapy between 1998 and 2008 for uveal melanoma, considering the above mentioned inclusion and exclusion criteria.


RESULTS
Two hundred and fifty-eight patients matched our inclusion criteria. Median follow-up was 72.6 months (12.0-167.4 months). Of these 258 patients, 71 patients (66.3 %) presented with cataract after 31.3 months (0.7-142.4 months), of whom 35 (20.4 %) required surgery after 24.2 (0.7-111.1 months) to ensure funduscopic tumor control. Kaplan-Meier estimates calculated a risk for cataract of 74.3 % after 5 years. There was no increase in metastasis or local recurrence in these patients. Patient's age was the sole independent statistically significant risk factor for cataract development. The probability of cataract occurrence significantly increased with doses to lens exceeding 15-20 CGE. Neither the appearance of cataract nor cataract surgery influenced long-term visual outcome.


CONCLUSIONS
Cataract formation is the most frequent complication after irradiation. There is no benefit vis-a-vis brachytherapy with regard to cataract development. Data indicate a dose-effect threshold of 0.5 CGE for cataractogenesis, with significantly increasing risk above a dose of 15 CGE. Furthermore, cataract surgery can be performed without an increased risk for metastasis.
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany. ira.seibel@charite.de.
Ira
I
Seibel
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.|Berlin Protonen am Helmholtz-Zentrum Berlin für Materialien und Energie, Charité Universitätsmedizin Berlin, Lise-Meitner-Campus, Berlin, Germany.
Dino
D
Cordini
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
Annette
A
Hager
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
Aline I
AI
Riechardt
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
Matus
M
Rehak
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
Alexander
A
Böker
Klinik für Strahlentherapie, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
Dirk
D
Böhmer
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.|Berlin Protonen am Helmholtz-Zentrum Berlin für Materialien und Energie, Charité Universitätsmedizin Berlin, Lise-Meitner-Campus, Berlin, Germany.
Jens
J
Heufelder
Augenklinik, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany.
Antonia M
AM
Joussen
D000293:Adolescent; D000328:Adult; D000368:Aged; D002386:Cataract / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007908:Lens, Crystalline / Q000000981:diagnostic imaging / Q000528:radiation effects*; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000532:radiotherapy*; D008875:Middle Aged; D061766:Proton Therapy / Q000009:adverse effects*; D011832:Radiation Injuries / Q000150:complications* / Q000175:diagnosis; D012189:Retrospective Studies; D013997:Time Factors; D014604:Uveal Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D055815:Young Adult; D000098943:Uveal Melanoma
Cataract; Irradiation dose; Proton beam irradiation; Uveal melanoma