Heufelder, J.; Cordini, D.; Stark, R.; Weber, A.; Gollrad, J.; Kourkafas, G.; Zeitz, O.; Denker, A.; Zips, D.; Joussen, A.M.: 25 Years of Ocular Proton Therapy in Berlin. International Journal of Particle Therapy 12 (2024), p. 100209/1
10.1016/j.ijpt.2024.100209
Open Access version by external provider
Abstract:
Background and aims: Technical progress and clinical results of 25 years ocular proton therapy (OPT) in Berlin will be presented. Methods: Since 1998 the Charité – Universitätsmedizin Berlin treats intra-ocular tumors at Helmholtz-Zentrum Berlin (HZB). The Department of Ophthalmology selects and prepares patients for OPT. This includes clip surgery, eye biometrics, and imaging for treatment planning (fundus imaging, ultrasound, ocular coherence tomography, CT and MRI). Until 2006 EYEPLAN was used as treatment planning system. In 2006 we changed to OCTOPUS, an in-house development of the HZB and the Deutsches Krebsforschungszentrum with full integration of fundus and 3D imaging (CT/MRI) into the treatment planning process. Treatment plan simulation and proton irradiation (typically 4 fractions) are performed at the HZB using their 68 MeV cyclotron with a dedicated ocular beam line. The patients are immobilized with a combination of bite block and thermoplastic head mask in sitting position. Axial and lateral X-rays in combination with an in-house developed positioning system are used to verify and correct the patient position. The radiation oncologist observes the correct eye position during the irradiation and can interrupt it manually if necessary. Aftercare is performed at the Department of Ophthalmology. Results: 4639 patients (47% male vs. 53% female; eye 49% right vs. 51% left) from Germany and other European countries were treated by the end of 2023. Patient age ranges typically between 40 and 80 years. Typical indications are small choroidal melanoma near posterior pole (60%), large choroidal or ciliary body melanoma (30%), iris melanoma (4%), re-irradiation after OPT or brachytherapy (3%) and hemangioma (3%). Typical observed side effects are cataract, radiation retinopathy, glaucoma and toxic tumor syndrome, which are handled by the ophthalmological aftercare. 5-year tumor control is better for iris melanoma (99%) than for choroidal melanoma (96%). Eye preservation for both modalities is 95%. Conclusions: These successes are based on excellent interdisciplinary cooperation between all disciplines, from ophthalmology and radiotherapy to medical physics and accelerator physics, as well as the continuous further development of the procedures and methods used. Acknowledgements Many thanks to the HZB accelerator crew for outstanding work over the last 25 years.