Outcomes of treatment with stereotactic radiosurgery or proton beam therapy for choroidal melanoma

Abstract

Aim To present our experience of the use of stereotactic radiosurgery and proton beam therapy to treat posterior uveal melanoma over a 10 year period. Methods and materials Case notes of patients treated with stereotactic radiosurgery (SRS), or Proton beam therapy (PBT) for posterior uveal melanoma were reviewed. Data collected included visual acuity at presentation and final review, local control rates, globe retention and complications. We analysed post-operative visual outcomes and if visual outcomes varied with proximity to the optic nerve or fovea. Results 191 patients were included in the study; 85 and 106 patients received Stereotactic radiosurgery and Proton beam therapy, respectively. Mean follow up period was 39 months in the SRS group and 34 months in the PBT group. Both treatments achieved excellent local control rates with eye retention in 98% of the SRS group and 95% in the PBT group. The stereotactic radiosurgery group showed a poorer visual prognosis with 65% losing more than 3 lines of Snellen acuity compared to 45% in the PBT group. 33% of the SRS group and 54% of proton beam patients had a visual acuity of 6/60 or better. Conclusions Stereotactic radiosurgery and proton beam therapy are effective treatments for larger choroidal melanomas or tumours unsuitable for plaque radiotherapy. Our results suggest that patients treated with proton beam therapy retain better vision postoperatively; however, possible confounding factors include age, tumour location and systemic co-morbidities. These factors as well as the patient's preference should be considered when deciding between these two therapies.

Uveal melanoma: physiopathology and new in situ-specific therapies

“…Stereotactic radiosurgery (SRS) uses emission of high-dose gamma radiation concentrated over a small volume [88,89]. Radiation energy is delivered to a well-defined area with little exposure to surrounding tissue.…”

“…Radiation energy is delivered to a well-defined area with little exposure to surrounding tissue. This ability to direct radiation to a precise target is advantageous when treating tumors near the macula and optic disk [88]. SRS works by damaging the DNA of the target cells, which then lose the ability to reproduce, causing tumors to shrink.…”

“…Sikuade et al [88] have studied the use of SRS and PBT to treat posterior uveal melanoma over a 10-year period. They verified that both treatments achieved excellent local control rates, concluding that these techniques are effective treatments for large choroidal melanomas or tumors unsuitable for plaque radiotherapy.…”

Particle therapy is ideal for the treatment of ocular melanomas

“…A recent comparison of patients treated with stereotactic radiation versus proton beam showed improved visual outcomes in the proton cohort. 7 Particle treatment has developed tremendously over the past decades in terms of treatment planning, dose delivery, and post-RT care to maintain a high level of tumor control while reducing the incidence and/or severity of side effects.…”

Novel mouse model for primary uveal melanoma: a pilot study

“…1 It is not only a threat to vision, but, even worse, it is also a life-threatening disease. Routinely used treatment options for the primary tumour consist of radiotherapy [2][3][4] or surgical procedures such as tumour resection and in severely advanced cases, the enucleation of the whole eye. 5,6 The reported tumour control rates are quite good.…”