Proton beam radiotherapy of uveal melanoma: Italian patients treated in Nice, France.

PURPOSE: To evaluate the results of 15 years of experience with proton beam radiotherapy in the treatment of intraocular melanoma, and to determine univariate and multivariate risk factors for local failure, eye retention, and survival. METHODS: A total of 368 cases of intraocular melanoma were treated with proton beam radiotherapy at Centre Lacassagne Cyclotron Biomedical of Nice, France, between 1991 and 2006. Actuarial methods were used to evaluate rate of local tumor control, eye retention, and survival after proton beam radiotherapy. Cox regression models were extracted to evaluate univariate risk factors, while regularized least squares algorithm was used to have a multivariate classification model to better discriminate risk factors. RESULTS: Tumor relapse occurred in 8.4% of the eyes, with a median recurrence time of 46 months. Enucleation was performed on 11.7% of the eyes after a median time of 49 months following proton beam; out of these, 29 eyes were enucleated due to relapse and 16 due to other causes. The univariate regression analysis identified tumor height and diameter as primary risk factors for enucleation. Regularized least squares analysis demonstrated the higher effectiveness of a multivariate model of five risk factors (macula distance, optic disc distance, tumor height, maximum diameter, and age) in discriminating relapsed vs nonrelapsed patients. CONCLUSIONS: This data set, which is the largest in Italy with relatively long-term follow-up, demonstrates that a high rate of tumor control, survival, and eye retention were achieved after proton beam irradiation, as in other series.

A networking for patient recruitment: the experience of choroidal melanoma.

The organization of a networking for patient recruitment is a main concern for a new facility using charged particles. The experience of choroidal melanoma in Nice demonstrates the possibility to create "de novo" a protontherapy center treating a sufficient number of patients. The influence of the opening of new facilities is analyzed.

Automatic three-dimensional model for protontherapy of the eye: preliminary results.

Recently, radiotherapy possibilities have been dramatically increased by software and hardware developments. Improvements in medical imaging devices have increased the importance of three-dimensional (3D) images as the complete examination of these data by a physician is not possible. Computer techniques are needed to present only the pertinent information for clinical applications. We describe a technique for an automatic 3D reconstruction of the eye and CT scan merging with fundus photographs (retinography). The final result is a "virtual eye" to guide ocular tumor protontherapy. First, we make specific software to automatically detect the position of the eyeball, the optical nerve, and the lens in the CT scan. We obtain a 3D eye reconstruction using this automatic method. Second, we describe the retinography and demonstrate the projection of this modality. Then we combine retinography with a reconstructed eye, using a CT scan to get a virtual eye. The result is a computer 3D scene rendering a virtual eye into a skull reconstruction. The virtual eye can be useful for the simulation, the planning, and the control of ocular tumor protontherapy. It can be adapted to treatment planning to automatically detect eye and organs at risk position. It should be highlighted that all the image processing is fully automatic to allow the reproduction of results, this is a useful property to conduct a consistent clinical validation. The automatic localization of the organ at risk in a CT scan or an MRI by automatic software could be of great interest for radiotherapy in the future for comparison of one patient at different times, the comparison of different treatments centers, the possibility of pooling results of different treatments centers, the automatic generation of doses-volumes histograms, the comparison between different treatment planning for the same patient and the comparison between different patients at the same time. It will also be less time consuming.