Gamma Knife Stereotactic Radiosurgery for Uveal Melanoma: Clinical Results after 2 Years

Abstract

We report on 36 cases of uveal melanoma treated at our center between March 1993 and September 1995. There were 16 men and 20 women, aged 57 ±11 years. The choroid was affected in 35 patients and the ciliary body in 1. The same preoperative and follow-up protocol was adopted for all cases. The procedure included fixation and positioning of the eye with a retrobulbar injection of long-lasting anesthetic and two extraocular muscle sutures, application of the frame, computed tomography scan localization, dose planning and treatment with the Gamma Knife. The patients were divided into three groups. Group A: 10 patients with a follow-up of 24 ± 4 months, treated with a high dose (surface dose 58 ± 9 Gy, maximum dose 81 ± 15 Gy, mean dose 66 ±11 Gy). Group B: 9 patients with a follow-up of 16 ± 2 months, treated with a lower dose (surface dose 41 ± 3 Gy, maximum dose 76 ± 10 Gy, mean dose 53 ± 11 Gy). Group C: 17 patients with a follow-up of 6 ± 3 months, treated with a lower dose (surface dose 42 ± 3 Gy, maximum dose 72 ±16 Gy, mean dose: 54 ± 6 Gy). In group A, we observed marked tumor regression in 9 cases, tumor recurrence in 1 case and severe complications in 5 cases (neovascular glacuoma and/ or radiation retinopathy and/or radiation optic neuropathy). In group B, significant local control of the tumor was obtained with minor complications (cotton wool spots, hard exudates, intraretinal hemorrhages). In group C, to date we have observed a regression of the tumor in 7 cases and 1 severe complication (neovascular glaucoma). Our data show that uveal melanomas may be adequately controlled by a high radiosurgical dosage (50–70 Gy), though there are significant side effects. Comparable levels of local tumor control may be obtainable using lower doses (40–45 Gy) which would hopefully reduce the rate of complications. However, a longer follow-up is needed for further validation of these results.

Gamma-Knife-Based Stereotactic Radiosurgery for Uveal Melanoma

“…Several retrospective series using GK-based for SRS to treat uveal melanoma and one series using the GK for fractionated stereotactic radiotherapy (fSRT) have now been reported [6][7][8][9][10][11][12][13] . Our own institutional experience was among these reports and showed excellent results with short follow-up [12] .…”

Gamma knife radiosurgery for uveal melanoma ineligible for brachytherapy by the Collaborative Ocular Melanoma Study criteria

“…Previous published series have suggested its effi cacy in the treatment of uveal melanomas where the rates of local tumor control, metastasis, and death have ranged from 84% to 100%, 11% to 26%, and 11% to 19%, respectively (Marchini et al 1996;Rennie et al 1996;Mullner et al 1998;Vecsei et al 1999;Mueller et (Table 3).…”

“…However, data from several case series suggest that GKS has comparable local tumor control rate, metastasis rate, mortality rate and complication rate to brachytherapy (Seddon et al 1990;Marchini et al 1996;Rennie et al 1996;Augsburger et al 1998Augsburger et al , 1999Mullner et al 1998;Vecsei et al 1999;Mueller et al 2000;Woodburn et al 2000;Zehetmayer et al 2000;Diener-West et al 2001;Haas et al 2002;Simonova et al 2002;Cohen et al 2003), as well as similar metastasis and mortality rates to enucleation, suggesting that tumor behavior may be more dependent upon intrinsic tumor characteristics, such as its cytogenetics (Baggetto et al 2005). Our fi ndings, like previous studies, suggest that GKS may be an appropriate alternative for treating uveal melanoma, especially when lesions are ineligible for conventional brachytherapy.…”

Role of proton therapy in the treatment of cancer

“…Lokal kontrol oranı %98, enükleasyona giden hasta oranı %10-15'dir. [35][36][37][38][39][40][41] Sonuç olarak, orbital melanomlarda lokal eksternal radyoterapi kabuledilebilir toksisite ile uygulanabilir. Şu an için proton tedavisinin foton tedavisine bir üstünlüğü gösterilememiştir.…”