Background/Aims. To report the safety and efficacy of strontium (Sr90) beta radiotherapy as adjuvant treatment for conjunctival melanoma. Methods. A retrospective cohort study was undertaken from 1999 to 2007 of all patients who underwent Sr90 beta radiotherapy for incompletely excised conjunctival melanoma. Failure of treatment was defined as recurrence of a conjunctival melanoma at the same location following beta radiotherapy. Results. Twenty patients underwent Sr90 beta radiotherapy for incompletely excised conjunctival melanoma. Median follow-up interval was 59 months (8–152). All patients had conjunctival melanoma involving the bulbar conjunctiva. Underlying diagnoses included PAM with atypia in 60% (12 of 20), PAM without atypia in 15% (3 of 20), and de novo conjunctival melanoma in 25% (5 of 20). Following Sr90 beta radiotherapy, in 90% (18 out of 20) local control was achieved and visual acuity was not affected in any patient. Three patients (15%) had dry eye symptoms, episcleritis, and descemetcoele, respectively. No cataract or secondary glaucoma was reported. Conclusions. Sr90 treatment is a very effective adjuvant treatment after excisional biopsy and cryotherapy for conjunctival melanoma with a local success rate of 90%. The treatment is not associated with significant side effects and visual acuity is not affected. 1. Introduction Conjunctival melanoma accounts for 1-2% of all ocular melanomas [1]. The management of conjunctival melanoma is fraught with difficulties. The majority of patients have the associated condition of primary acquired melanosis (PAM) with atypia and are therefore prone to multiple new tumours throughout their lifetime [2, 3]. Recurrent or incompletely excised conjunctival melanoma is associated with an increased risk of metastases [3]. Therefore, primary conjunctival melanoma is managed by complete excision and double freeze-thaw cryotherapy. Adjuvant therapy is necessary to improve local tumour control and survival of the patient especially when the histopathology reports indicate tumour is present at the surgical margins. Adjuvant therapy includes cryotherapy [4], topical mitomycin C [5], brachytherapy [6–8], proton beam radiotherapy [9], or rarely alpha 2b interferon [10]. Brachytherapy includes the use of ruthenium-106, [6, 7] iodine-191 [8], or strontium-90 beta radiotherapy. Strontium-90 (Sr90) beta radiotherapy is a noninvasive treatment using a hand held applicator (Figure 1). It has also been used for controlling wound healing after glaucoma drainage surgery [11]. It is only available for the treatment of
References
[1]
B. Damato and S. E. Coupland, “An audit of conjunctival melanoma treatment in Liverpool,” Eye, vol. 23, no. 4, pp. 801–809, 2009.
[2]
C. L. Shields, J. A. Shields, K. Gündüz et al., “Conjunctival melanoma: risk factors for recurrence, exenteration, metastasis, and death in 150 consecutive patients,” Archives of Ophthalmology, vol. 118, no. 11, pp. 1497–1507, 2000.
[3]
C. L. Shields, J. S. Markowitz, I. Belinsky et al., “Conjunctival melanoma: outcomes based on tumor origin in 382 consecutive cases,” Ophthalmology, vol. 118, no. 2, pp. 389–395, 2011.
[4]
F. A. Jakobiec, F. J. Rini, F. T. Fraunfelder, and S. Brownstein, “Cryotherapy for conjunctival primary acquired melanosis and malignant melanoma. Experience with 62 cases,” Ophthalmology, vol. 95, no. 8, pp. 1058–1070, 1988.
[5]
L. C. Ditta, Y. Shildkrot, and M. W. Wilson, “Outcomes in 15 patients with conjunctivalmelanoma treated with adjuvant topical mitomycin C: complications and recurrences,” Ophthalmology, vol. 118, no. 9, pp. 1754–1759, 2011.
[6]
M. Zehetmayer, R. Menapace, and W. Kulnig, “Combined local excision and brachytherapy with ruthenium-106 in the treatment of epibulbar malignancies,” Ophthalmologica, vol. 207, no. 3, pp. 133–139, 1993.
[7]
L. Krause, A. Mladenova, N. E. Bechrakis, et al., “Treatment modalities for conjunctival melanoma,” Klinische Monatsbl？tter für Augenheilkunde, vol. 226, no. 12, pp. 1012–1016, 2009.
[8]
J. A. Shields, C. L. Shields, J. E. Freire, L. W. Brady, and L. Komarnicky, “Plaque radiotherapy for selected orbital malignancies: preliminary observations—the 2002 montgomery lecture, part 2,” Ophthalmic Plastic and Reconstructive Surgery, vol. 19, no. 2, pp. 91–95, 2003.
[9]
H. Wuestemeyer, W. Sauerwein, D. Meller et al., “Proton radiotherapy as an alternative to exenteration in the management of extended conjunctival melanoma,” Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 244, no. 4, pp. 438–446, 2006.
[10]
T. R. Herold and C. Hintschich, “Interferon alpha for the treatment of melanocytic conjunctivallesions,” Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 248, no. 1, pp. 111–115, 2010.
[11]
J. F. Kirwan, P. H. Constable, I. E. Murdoch, and P. T. Khaw, “Beta irradiation: new uses for an old treatment: a review,” Eye, vol. 17, no. 2, pp. 207–215, 2003.
[12]
“Uveal melanoma 591-610,” in GEC ESTRO Handbook of Brachytherapy, R. Potter and E. van Limbergen, Eds., 2012, http://www.estro-education.org/publications/Pages/ESTROHandbooks.aspx.
[13]
P. K. Lommatzsch, “Beta irradiation of conjunctival melanomas,” Transactions of the Ophthalmological Societies of the United Kingdom, vol. 97, no. 3, pp. 378–380, 1977.
[14]
P. K. Lommatzsch, “Beta-Ray treatment of malignant epibulbarmelanoma,” Albrecht von Graefe's Archive for Clinical and Experimental Ophthalmology, vol. 209, no. 2, pp. 111–124, 1978.
[15]
L. Krause, C. Ritter, J. Wachtlin, et al., “Recurrence rate following adjuvant strontium-90 brachytherapy after excision of conjunctivalmelanoma,” Klinische Monatsbl？tter für Augenheilkunde, vol. 225, no. 7, pp. 649–652, 2008.
[16]
G. Missotten, R. J. W. De Keizer, W. Spileers, et al., “Strontium brachytherapy in conjunctival melanoma (abstract),” Acta Ophthalmol, vol. 89, article S248, 2011.
[17]
G. Missoten, M. J. Tassignon, and R. J. X. De Kaizer, “Strontium brachytherapy in conjunctival melanoma(abstract). SBO-BOG,” 2008, http://www.ophthalmologia.be/plugins/abstracts/view_abstract.php?abs_id=1402.
[18]
J. J. Khong and J. Muecke, “Complications of mitomycin C therapy in 100 eyes with ocular surface neoplasia,” British Journal of Ophthalmology, vol. 90, no. 7, pp. 819–822, 2006.
[19]
H. C. Russell, V. Chadha, D. Lockington, and E. G. Kemp, “Topical mitomycin C chemotherapy in the management of ocular surface neoplasia: a 10-year review of treatment outcomes and complications,” British Journal of Ophthalmology, vol. 94, no. 10, pp. 1316–1321, 2010.
[20]
P. T. Finger, G. Czechonska, and S. Liarikos, “Topical mitomycin C chemotherapy for conjunctival melanoma and PAM with atypia,” British Journal of Ophthalmology, vol. 82, no. 5, pp. 476–479, 1998.
[21]
H. Westekemper, G. Anastassiou, W. Sauerwein et al., “Analysis of ocular surface alterations following proton beam radiation in eyes with conjunctival malignant melanoma,” Ophthalmologe, vol. 103, no. 7, pp. 588–595, 2006.
