31 Uveal Melanoma

Uveal Melanoma

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THE GEC ESTROHANDBOOKOF BRACHYTHERAPY | Part II Clinical Practice Version 1 - 15/04/2020

31 Uveal Melanoma

Luca Tagliaferri, Maria Antonietta Blasi, Carien Creutzberg, Gerd Heilemann, Erik Van Limbergen, Richard Pötter

1. Summary 2. Introduction

3 3 4 4 5 5 8 8

9. Treatment planning

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10. Dose, dose rate and fractionation

11 12 12 15 18 18

3. Anatomical topography

11. Monitoring

4. Pathology 5. Work up

12. Results

13. Adverse side effects 14. Key messages

6. Indications, contra-indications 7. Tumour and target volumes

15. References

8. Technique

1. SUMMARY

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults and accounts for 5% of all melanomas and includes melanoma arising in the iris, ciliary body and choroid. The diagnosis is based on the ocular oncologist’s comprehensive clinical judgement taking into account results from the different diagnostic methods applied. Enucleation has been the treatment of choice for decades, until some European experience especially using Ruthenium-106 plaques and later the Collaborative Ocular Melanoma Study (COMS) demonstrated that mortality rates following brachytherapy for small andmedium-sized uveal melanoma did not differ from those following enucleation for up to 12 years after treatment. Multiple eye-conserving treatment options are now available for the majority of UM including transpupillary thermotherapy, trans-scleral resection, and radiotherapy using episcleral brachytherapy, charged particle radiotherapy (protons) or stereotactic photon radiotherapy. Enucleation remains an accepted treatment for large choroidal melanoma. Brachytherapy is the most commonly used conservative treatment for UM. The Clinical Target Volume (CTV) is determined based on pretreatment findings from ophthalmoscopy and ultrasound scan. Different radioisotopes can be used for ocular brachytherapy. Ruthenium-106 ( 106 Ru) and Iodine-125 ( 125 I) are the most widely used. Plaques loaded with Iodine-125 seeds can be used both for the treatment of small lesions and for the treatment of larger lesions. 106Ru plaques, based on a beta-emitter, are to be used for small and medium-sized lesions, generally less than 5-6mm in thickness, with the advantage of reduced dose to the lens and other parts of the retina. Dosimetry can be performed manually or by software that allows 3D processing of the dose. The use of 3D software for preplanning may improve treatment planning. Treatment results and morbidity are specific for the different isotopes Ruthenium-106 and Iodine-125. There is a considerable amount of data available, reflecting the broad experience with the 106 Ru eye plaque brachytherapy, largely used in Europe. 106 Ru brachytherapy represents a good treatment option for small andmedium-sizedmelanomas with local control rates between 78-95%. Based on AJCC staging for posterior uveal melanoma, 10-year metastatic rate is 12% for stage I, 29% for stage II, and 61% for stage III tumours. The risk of metastasis and death increases three-fold with each increasing melanoma stage. However, it has become increasingly apparent that genetic features of the primary uveal melanoma, such as chromosome 3 status and gene expression profile, are more sensitive than size as a predictor of metastasis and death. Enucleation is required in 4-6% of all patients, usually during the first years, either for tumour recurrence or toxicity. Although enucleation has been the gold standard for the treatment of recurrences, retreatment with episcleral plaque represents an excellent option, especially for marginal recurrences.

2. INTRODUCTION

higher incidence at 4.9 cases per million than do females at 3.7 cases per million. UM is diagnosed at older ages, with a progressively rising, age-specific, incidence rate that peaks near the age of 70 years. Uveal melanoma arises from melanocytes situated in the uveal tract of the eye, and can affect any part of the uveal tract, but choroidal melanoma is predominant (85-90%), while iris and ciliary body melanomas are far less frequent accounting for 9–15% of cases. Iris melanomas are associated with the earliest detection and overall best prognosis, while ciliary body melanomas are

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults and accounts for 5% of all melanomas. It is most commonly found in light complexion Caucasians with an age-adjusted incidence of 4.3 per million people. In Europe, the incidence of uveal melanoma follows a north-to-south decreasing gradient ranging from 2 to 8 per million population. Males have a