brachytherapy Ru plaque 106 melanomas following Predicting local control of choroidal

Background We evaluated the control rate of choroidal melanomas treated with Ru plaque brachytherapy to identify the risk factors associated with local recurrence and lack of response. Methods A retrospective review of Ru plaque brachytherapy for patients with choroidal melanoma treated at St Bartholomew’s Hospital, London. Survival analysis was used to assess associations between evaluated age, sex, location, foveal proximity, tumour base and height, presence of lipofuscin and subretinal fluid, apex dose, radiation rate and type of plaque with time to local recurrence. Logistic regression analysis was used to assess to evaluate the association between the same set of variables and lack of tumour response. Results From January 2002 to December 2006 189 patients were treated. The follow-up ranged from 12 to 78 (median 33) months. None of the patients received adjuvant diode laser thermotherapy. The control rate was 85.7% (14 recurred while 13 did not respond). Of the patients who had local recurrence, univariate survival analysis demonstrated an association with younger patients, foveal proximity, preoperative subfoveal fluid and tumour base >11 mm. Age and foveal proximity remained significant in a Cox multiple variable model (p1⁄40.03). Of the patients who did not respond, logistic regression analysis showed that lack of response was associated with a tumour height >5 mm, confirmed through multiple variable analysis (p1⁄40.027). Conclusions Tumours that are close to the fovea in young patients appear more likely to show local recurrence. Tumour height >5 mm was the only prognostic factor that determined lack of response. These results may be used to select which tumours require adjuvant therapy. INTRODUCTION Published data on the growth rate of uveal melanoma and effect on tumour control of different treatment modalities have raised important concerns over the appropriate choice of treatment. Since the introduction of Ruplaque brachytherapy by Lommatzsch and Vollmar in 1964, this type of globe-conserving procedure has been widely accepted in many centres throughout Europe. In 1991 the Collaborative Ocular Melanoma Study demonstrated that for medium-sized choroidal melanoma, patient survival was comparable with enucleation. Plaque brachytherapy offers the patient a perceived better quality of life with the potential to preserve vision and the eye. However, the application of Ru plaque brachytherapy is limited by a steep dose-gradient in tissue, with the upper limit of penetration judged to be approximately 5 mm. Therefore, this radioisotope is only suitable for small to medium-sized melanomas. Adjuvant treatment with diode laser thermotherapy may allow better tumour control for more elevated melanomas with the potential to reduced radiation complications. During the study period, however, diode laser thermotherapy was not used as routine adjuvant therapy for uveal melanoma and was only performed for local recurrence. The aim of this study was to identify the clinical factors associated with local tumour recurrence and lack of tumour response following treatment of choroidal melanoma with Ru plaque brachytherapy in order to provide an evidence-based strategy to select patients who may benefit from adjuvant diode laser thermotherapy. PATIENTS AND METHODS A retrospective review was undertaken on patients with posterior uveal melanomas, treated with Ru plaque brachytherapy from January 2002 to December 2006, at the Ocular Oncology Unit of St Bartholomew’s Hospital in London. The inclusion criteria were patients with posterior uveal melanomas (choroidal tumours with no ciliary body component) treated solely with Ru plaque brachytherapy, and who had at least 1 year of follow-up in the service. Patients were excluded from the study if there was insufficient follow-up information in the medical records or if they had received adjuvant diode laser thermotherapy. The diagnosis of posterior uveal melanoma was based on the findings of comprehensive ophthalmic examination supplemented by B scan ultrasonography and fundal photography. Tumours were treated with Ru brachytherapy, using commercial radioactive plaques (BEBIG, Berlin, Germany). Both indirect ophthalmoscopy and transillumination were used to demarcate tumour margins intraoperatively. Dummy plaques were placed initially to ensure that all tumour margins were within the field of irradiation. All tumours received at least a 2 mm safety margin. Active plaques were subsequently positioned and left in place until the prescribed treatment dose had been delivered to the tumour apex. After irradiation, follow-up visits took place at 1, 3, 6 and 12 months post-brachytherapy, then twice a year until the second post-operative year and annually thereafter. Follow-up evaluation included best corrected visual acuity, ophthalmoscopic and ultrasonographic assessment of local tumour control and brachytherapy-related complications. All data were collected retrospectively. Demographic data included age, sex and race of the Department of Ophthalmology, St Bartholomew’s and the London NHS Trust, West Smithfield, London, UK Department of Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust, London, UK Medical Statistics, Research and Development, Moorfields Eye Hospital NHS Foundation Trust, London, UK Correspondence to Dr Victoria Cohen, Consultant in Ocular Oncology, Department of Ophthalmology, Barts and the London NHS Trust, West Smithfield, London EC1A 7BE, UK; victoria.cohen@ bartsandthelondon.nhs.uk Accepted 17 February 2010 Published Online First 1 October 2010 166 Br J Ophthalmol 2011;95:166e170. doi:10.1136/bjo.2009.176198 Review group.bmj.com on January 21, 2011 Published by bjo.bmj.com Downloaded from