Juliette Thariat1,2, Sophie Jacob3, Jean-Pierre Caujolle4, Celia Maschi4, Stéphanie Baillif4, Gaelle Angellier1, Thibaud Mathis5, Laurence Rosier6, Adela Carnicer1, Joel Hérault1, Julia Salleron7. 1. Institution, Department of Radiation Oncology-Proton Therapy, Nice, France. 2. Centre Francois Baclesse, Department of Radiation Oncology, Normandie Universite - Unicaen, Caen, France. 3. Laboratory of Epidemiology, Institut de Radioprotection et de Sureté Nucléaire (IRSN), PRP-HOM, SRBE, LEPID, Fontenay-aux-Roses, France. 4. Department of Ophthalmology, University Hospital Pasteur 2, Nice, France. 5. Department of Ophthalmology, Eye University Clinic la Croix Rousse, Lyon, France. 6. Eye Clinic, Centre d'Exploration et de Traitement de la Retine et de la Macula, Bordeaux, France. 7. Department of Biostatistics, Institut de Cancérologie de Lorraine, Vandoeuvre les Nancy, France.
Abstract
Purpose: The lens is a radiosensitive organ. Any dose of cephalic irradiation can give rise to radiation-induced cataracts. Contrary to other forms of radiotherapy, proton therapy (PT) can spare all or part of the lens due to accurate dose deposition. We investigated whether a lens-sparing approach was relevant to avoid cataracts in uveal melanoma patients. Methods: Patients were referred for PT from onco-ophthalmologists of private and academic institutions. Patients without preexisting cataracts or implants were entered in a prospective database. Dose thresholds responsible for cataracts were investigated in volumes of lens or lens periphery. Lens opacifications and de novo vision-impairing cataracts (VICs) had biannual follow up by ophthalmologists blinded to lens dose. Correlations between dose-volume relationships and VICs were assessed using univariate/multivariate regressions. Results: Between 1991 and 2015, 1696 uveal melanoma patients were consecutively treated with PT. After a median follow up of 48 months, 14.4% and 8.7% of patients had cataracts and VIC within median times of 19 and 28 months, respectively. Median values of mean lens and lens periphery doses were 1.1 (radiobiologically effective [RBE] dose in photon-equivalent grays [GyRBE]) and 6.5 GyRBE, respectively. The lens received no dose in 25% of the patients. At an irradiated lens volume of ≤5%, there was no significantly increased risk for VIC below a dose of 10 GyRBE. Conclusions: A lens-sparing approach is feasible and results not only in reduced need for cataract surgery but also in better fundus-based tumor control. Reassessment of radioprotection rules for lens dose thresholds may follow.
Purpose: The lens is a radiosensitive organ. Any dose of cephalic irradiation can give rise to radiation-induced cataracts. Contrary to other forms of radiotherapy, proton therapy (PT) can spare all or part of the lens due to accurate dose deposition. We investigated whether a lens-sparing approach was relevant to avoid cataracts in uveal melanomapatients. Methods:Patients were referred for PT from onco-ophthalmologists of private and academic institutions. Patients without preexisting cataracts or implants were entered in a prospective database. Dose thresholds responsible for cataracts were investigated in volumes of lens or lens periphery. Lens opacifications and de novo vision-impairing cataracts (VICs) had biannual follow up by ophthalmologists blinded to lens dose. Correlations between dose-volume relationships and VICs were assessed using univariate/multivariate regressions. Results: Between 1991 and 2015, 1696 uveal melanomapatients were consecutively treated with PT. After a median follow up of 48 months, 14.4% and 8.7% of patients had cataracts and VIC within median times of 19 and 28 months, respectively. Median values of mean lens and lens periphery doses were 1.1 (radiobiologically effective [RBE] dose in photon-equivalent grays [GyRBE]) and 6.5 GyRBE, respectively. The lens received no dose in 25% of the patients. At an irradiated lens volume of ≤5%, there was no significantly increased risk for VIC below a dose of 10 GyRBE. Conclusions: A lens-sparing approach is feasible and results not only in reduced need for cataract surgery but also in better fundus-based tumor control. Reassessment of radioprotection rules for lens dose thresholds may follow.
Authors: Charlotte A Espensen; Ane L Appelt; Lotte S Fog; Anita B Gothelf; Juliette Thariat; Jens F Kiilgaard Journal: Cancers (Basel) Date: 2019-08-06 Impact factor: 6.639
Authors: Bianca A W Hoeben; Enrica Seravalli; Amber M L Wood; Mirjam Bosman; Witold P Matysiak; John H Maduro; Astrid L H M W van Lier; Matteo Maspero; Gijsbert H Bol; Geert O Janssens Journal: Clin Transl Radiat Oncol Date: 2021-08-29