Proton Ocular Radiotherapy (PORT)
Proton ocular radiotherapy (PORT) is an alternative to enucleation and conventional eye plaque therapy. Conventional treatments for choroidal melanoma are enucleation (removal of the eye) and radiation therapy using eye plaques. Eye plaque therapy uses a radioactive cup sutured to the surface of the eye (over the tumor) and kept in place for up to a week before it is removed. PORT is used to treat:
- ocular melanomas
- metastatic lesions contained within the eye
A patient sitting in an adjustable chair in preparation for treatment of the eye.
Tumors located in the very back of the eye and under orbital muscles are very difficult to treat with plaque therapy because it is not possible to suture the plaque over the tumor without causing significant damage to the muscles or nerves. PORT does not require covering the tumor with a solid plaque and therefore its application is much less flexible.
The success of PORT treatments is very impressive with approximately 3,500 patients treated with a 5-year local control of 98% and 95% for small/medium and large ocular melanomas, respectively. The overall 5-year metastases-free survival is 80% with a better outcome for smaller lesions (95%) and a worse outcome (60%) for larger lesions. Improvement of vision depends on the original condition of the eye, tumor size and location and whether there is retinal detachment.