Long-Term Visual Outcomes for Small Uveal Melanoma Staged T1 Treated by Proton Beam Radiotherapy

Abstract

There is increasing evidence of the survival benefit of treating uveal melanoma in an early stage, however it is important to discuss with the patient the associated risk of visual loss. We investigated visual outcomes for uveal melanomas staged T1 (T1UM) treated by proton beam radiotherapy (PBR) as a function of their distance to fovea-optic disc. This retrospective study included a cohort of 424 patients with T1UM treated with PBR between 1991 and 2010 with at least a 5-year follow-up. Visual acuity (VA) was analyzed for patients with posterior edge of tumor located at ≥3 mm (GSup3) or <3 mm (GInf3) from fovea-optic disc. The mean follow-up duration was 122 months, no tumor recurrence was observed. The mean baseline and final VA were 20/25 and 20/32 for GSup3 (n = 75), and 20/40 and 20/80 for GInf3 (n = 317) respectively. The frequency of a 20/200 or greater visual conservation was 93.2%(CI95%:87.7–99.1) and 60.1%(CI95%:54.9–65.9) for GSup3 and GInf3 respectively. This difference between groups was statistically significant (p < 0.001). The risk factors for significant VA loss (less than 20/200) were GInf3 location (p < 0.001), tumor touching optic disc (p = 0.04), initial VA inferior to 20/40 (p < 0.001), documented growth (p = 0.002), and age greater than 60 years (p < 0.001). In summary, PBR for T1UM yields excellent tumor control and good long-term visual outcomes for tumors located ≥3 mm from fovea-optic disc.

Visual outcomes of proton beam therapy for choroidal melanoma at a single institute in the Republic of Korea

“…For these reasons, an understanding of long-term visual outcomes and their associations with radiation treatment planning parameters are critical for optimal care of choroidal melanoma patients. There have been several reports on visual outcomes after radiation therapy, as well as on factors associated with visual outcomes [14,[17][18][19]. It is well known that tumor height and distance of the tumor from the optic disc or fovea are commonly associated with the final VA [18][19][20].…”

“…There have been several reports on visual outcomes after radiation therapy, as well as on factors associated with visual outcomes [ 14 , 17 – 19 ]. It is well known that tumor height and distance of the tumor from the optic disc or fovea are commonly associated with the final VA [ 18 – 20 ]. These studies had many patients, and long follow-up periods; therefore, they showed similar results.…”

Improving organs-at-risk sparing for choroidal melanoma patients: A CT-based two-beam strategy in ocular proton therapy with a dedicated eyeline

“…Long-term clinical outcomes [25,[36][37][38][39] reported in the literature are based on the existing geometrical eye model [1] available in EYEPLAN and EOPP (Varian Medical Systems Particle Therapy GmbH & Co. KG, Troisdorf, Germany) software, which is less accurate than 3D delineations based on CT or MRI [14,17,40]. A translation to an expected reduction in complications is therefore difficult to make.…”

Proton beam radiotherapy for choroidal and ciliary body melanoma in the UK—national audit of referral patterns of 1084 cases

“…Some recent studies suggested that early treatment of UM may have a beneficial effect on survival (9)(10)(11). PBR could be of particular advantage, as the damaging side effects on vision caused by the destruction of non-malignant tissue surrounding the tumour seem to be less pronounced in small T1 tumours compared to other methods of radiotherapy (12). This could lower the threshold for early treatment of small tumours near the fovea and disc.…”