Radiotherapeutic and surgical management of iris melanoma: A review

Occupational Exposure to Low Dose Ionizing Radiation and the Incidence of Surgically Removed Cataracts and Glaucoma in a Cohort of Ontario Nuclear Power Plant Workers

Ionizing radiation is a human carcinogen and has been shown to increase the risk of non-cancerous ocular disorders. Specifically, findings from epidemiological studies suggest that ionizing radiation leads to the development of cataracts and to a lesser extent glaucoma, however, there are uncertainties of these risks at lower exposures. We analyzed data from a cohort of 60,874 Ontario Nuclear Power Plant (NPP) workers within the Canadian National Dose Registry (NDR). These workers were monitored for whole-body exposure to ionizing radiation using dosimeters, with exposure estimates derived for each year of employment. Incident cases of surgically removed cataracts and glaucoma were identified through the record linkage of occupational histories to administrative health data for Ontario between 1991 and 2022. We compared the incidence of surgically removed cataracts and glaucoma in the cohort to Ontario's general population using indirect age- and sex-standardization with matching by place of residence. We evaluated exposure-response relationships with internal cohort comparisons using age-, sex-, and calendar-period-adjusted Poisson regression. The relative risks of cataract and glaucoma were estimated across categorical measures of whole-body dose [Hp(10)] from exposure to radiation (lagged 5 years). In total, 32,855 of the 60,874 workers (58%) had a positive cumulative dose exceeding the minimum reportable threshold. Among these workers, the mean cumulative whole-body lifetime dose at end of follow-up was 23.7 mSv (interquartile range: 1.1-26.4 mSv, maximum = 959.3 mSv). Overall, 4,401 (7.2%) of workers developed glaucoma, while 2,939 (4.8%) underwent cataract-removal surgery. There was no evidence of a dose-response relationship between cumulative whole-body dose ionizing radiation (lagged 5 years) and glaucoma, but some for surgically removed cataracts. Specifically, among workers with a cumulative exposure of greater than 50 mSv relative to those with an exposure of less than 0.25 mSv, the relative risks of incident glaucoma and cataract removal surgery were 0.91 (95% CI: 0.81-1.05) and 1.13 (95% CI: 0.97-1.33), respectively. The linear excess risks per 100 mSv (lagged 5 years) for cataract removal surgery was 0.055 (95% CI: -0.042 to 0.163). Our findings provide some evidence that ionizing radiation increases the risk of cataracts but not glaucoma in an occupational cohort whose lifetime cumulative dose rarely exceeded 30 mSv.

Iris melanoma in an Australian cohort

BACKGROUND

To report the clinicopathological features and epidemiology of iris melanoma in Queensland, Australia.

METHODS

This was a retrospective study of 86 patients with iris melanoma treated between 2001 and 2022 at the Queensland Ocular Oncology Service, Brisbane, Australia. Main outcome measures included demographics, clinical and phenotypic features, age-adjusted incidence and relative survival.

RESULTS

Eighty-six patients (63% female) were included. Mean age was 54 years (range 17-82 years). The majority of patients (97%) were Caucasian, with blue eyes, fair skin and Fitzpatrick Skin Type I or II. Demographic features and clinical history showed a tendency for high ultraviolet radiation (UVR) exposure in the cohort. Histopathology was available in 69 cases (82%), and of these, 77% tumours were of spindle cell origin, with low-risk genetic profiles. Patients were followed for a mean of 8 years (median 7, range 1-21 years) after diagnosis, and only one case of metastasis was documented.

CONCLUSIONS

The association of iris freckles, history of UVR exposure and dermatologic findings supports the role of UVR in iris melanoma. Occupation and avocation history, as well as evaluation of iris freckles may offer an easily accessible way of stratifying the risk of an individual for development of UVR-related uveal melanoma.

Effectiveness of treatment for iris melanoma: surgical versus radiotherapeutic approaches

OBJECTIVE

To evaluate the effectiveness of preventing metastasis for each major treatment modality for iris melanoma.

DESIGN

Retrospective case series.

PARTICIPANTS

Three hundred consecutive eyes with iris melanoma at a single tertiary referral centre for ocular oncology.

METHODS

Retrospective analysis of eyes with iris melanoma, both with (n = 69 eyes) and without (n = 231 eyes) ciliary body extension, was undertaken for metastasis-free survival at 5, 10, and 20 years based on type of treatment, including globe-sparing surgical resection (n = 169 eyes), plaque radiotherapy (n = 74 eyes), or enucleation (n = 57 eyes).

RESULTS

For the total population, 5-, 10-, and 20-year metastasis-free survival rates were 95%, 93%, and 87%, respectively, and there was no difference in metastatic rates for tumours with versus without ciliary body extension (p = 0.95). Noninferiority was demonstrated for surgical resection and plaque radiotherapy, with metastasis-free survival rates of 98%, 97%, and 94% for surgical resection and 94%, 94%, and 89% for plaque radiotherapy (p = 0.002). The rates for globe salvage were 94%, 92%, and 90% for surgical resection and 94%, 86%, and 86% for plaque radiotherapy (p = 0.003). However, metastasis-free survival was worse in patients who underwent enucleation (86%, 67%, and NA; p < 0.001).

CONCLUSIONS

Metastasis-free survival and globe salvage following plaque radiotherapy and surgical resection are not inferior to either, but eyes undergoing enucleation demonstrated a lower metastasis-free survival, likely because enucleation is performed for larger, more extensive melanomas, often with secondary glaucoma. In this analysis, iris melanoma with ciliary body involvement did not increase the risk of metastasis.

Current management of uveal melanoma: A review

Uveal melanoma is the most frequent primary intraocular cancer in adulthood and is mostly localised to the choroid. It can be treated using radiation therapy, laser therapy, local resection and enucleation, with the best results achieved by combining these procedures. However, up to half of patients develop metastatic disease. There are no efficacious treatment methods for patients in advanced stage or with metastasis. In recent years, several novel treatment modalities aimed at improving tumour control and reducing adverse events have emerged. This review summarises current clinical treatment methods and new therapeutic perspectives for uveal melanoma.

Clinical Outcomes after Surgical Resection Combined with Brachytherapy for Uveal Melanomas

Currently, brachytherapy is the most commonly used therapeutic approach for uveal melanomas. Surgical resection by means of endoresection or exoresection is an alternative approach. The present report recounts our experience over 15 years in the treatment of uveal melanoma using a combined approach of resection surgery with brachytherapy. This is a single-center observational retrospective cohort study in which we describe clinical outcomes, complications and survival in 35 cases of melanoma of the iris or the ciliary body after a combination of surgery and brachytherapy or brachytherapy alone. Local treatment of the tumor was successful in all cases with surgery and brachytherapy. The most frequent complications were scleromalacia, bullous keratopathy, retinal toxicity, cataracts, hypotonia, and photophobia. There were three cases of recurrence, all of which were found in the group of patients who had received brachytherapy alone, and in one case we had to perform a secondary enucleation due to tumor growth after brachytherapy. At present, only one patient has died during follow-up due to liver metastases six years after the start of treatment. In carefully selected patients, this approach can be effective and safe, as long as a close follow-up is carried out after surgery.

Case Series: Different Presentations of Iris Melanoma-Potential Masquerade of Benign and Malignant

SIGNIFICANCE

Iris melanoma and iris nevi can be challenging to distinguish clinically. This case series provides unique insight into the rare condition and variable clinical presentations of iris melanoma.

PURPOSE

This study aimed to highlight the varying clinical presentations of iris melanoma and to demonstrate the overlapping features of melanoma and nevi.

CASE REPORTS

This case series includes five patients of varying age and sex who presented to clinic with pigmented iris lesions. These five patients have differing timeline to presentation and very different clinical presentations of their lesions. Clinical evaluation was based around the established "ABDCEF" guide for the assessment of malignant risk in iris lesions. The presentation of each lesion is discussed in relation to this guide and the experienced clinician's clinical suspicion of malignancy. When comparing the clinical suspicion with histological analysis, after biopsy, the result may be unexpected. Notably, initially benign nevi may transform into melanoma over time. These five cases were managed on an individual basis because the management and prognosis of iris melanomas vary significantly. Importantly, iris melanotic lesions have variable metastatic risk based on cytology and genetic predisposition. Informed consent was obtained from all the patients, institutional approval was obtained, and no identifiable health information is included in this case series.

CONCLUSIONS

When presented with a pigmented iris lesion, clinicians must be vigilant with regular monitoring and have a low threshold for biopsy in pigmented lesions of high clinical suspicion.

Proton beam radiation for iris melanoma: case series and review of literature

Objective

Purpose of this study is to analyse the visual outcomes, the complication and eye retention rate as well as tumour control data of patients treated with proton beam radiation therapy (PBRT) for iris melanoma.

Methods

Retrospective case series and review based on patients’ records. All tumours were categorised according to the American Joint Committee of Cancer staging criteria for primary iris melanoma und underwent either sectorial or whole anterior segment PBRT.

Results

Thirteen cases were identified of which five received PBRT of the whole anterior segment and eight received sectorial PBRT. Local tumour control after a mean follow-up of 25 months was 92%. Complications after PBRT included cataract (46%), secondary glaucoma (31%), superficial keratitis (15%) and madarosis (8%). Complications were more common in patients necessitating irradiation of the entire anterior segment than in patients which received sectorial irradiation. Eye retention was achieved in all cases. No statistically significant difference in the mean best corrected visual acuity (BCVA) and intraocular pressure (IOP) was found before and after treatment. Comparison of mean BCVA and IOP between different treatment groups (complete anterior segment vs sectorial irradiation) at the last follow-up visit were also not significantly different. No patient developed metastatic disease during follow-up.

Conclusion

PBRT is a safe and vision preserving therapeutic modality for iris melanoma. Complete irradiation of the anterior segment is associated with higher complication rates.

Clinical outcomes of Modified Collaborative Ocular Melanoma Study IRIS plaques for treatment of iris, iridociliary, and ciliary body melanoma

BACKGROUND/OBJECTIVES

To report clinical outcomes of modified Collaborative Ocular Melanoma Study IRIS (COMS IRIS) plaques for treatment of iris, iridociliary, and ciliary body melanoma.

SUBJECTS/METHODS

Retrospective, single-centre cohort study of iris melanoma treated with COMS IRIS plaque radiotherapy from July 26, 2010 to October 15, 2018. Medical records were reviewed for demographics, tumour features, treatment parameters, and clinical outcomes.

RESULTS

There were 22 cases, diagnosed at mean age of 59 years (median 65, range 21-85 years) with female sex in 14 (64%). Presenting tumour features included Snellen visual acuity (VA) ≥ 20/40 in 18 (82%) cases, mean largest tumour basal diameter 4.7 mm (median 3.9, range 2.3-13.8 mm) and thickness 1.7 mm (median 1.6 mm, range 0.8-3.9 mm), iris stromal seeding in 3 (14%) cases, angle seeding in 16 (73%), and ciliary body involvement in 13 (59%). After mean follow-up of 51 months (median 44, range 4-113 months), Snellen VA was ≥20/40 in 14 (64%) cases, with local tumour recurrence in 2 (9%), and enucleation in 2 (9%). The 3-year Kaplan-Meier estimated risk of local tumour recurrence was 7%. The most common radiation side effects were cataract in 17 (77%) patients and dry eye in 5 (23%). Systemic metastasis occurred in no cases, and 1 (5%) non-melanoma-related death due to natural causes was observed at last follow-up.

CONCLUSIONS

COMS IRIS plaques are effective for treatment of iris, iridociliary, and ciliary body melanoma with modest VA outcomes and low frequency of local tumour recurrence, enucleation, radiation side effects, and systemic metastasis.

Robotic assisted CyberKnife radiosurgery for the treatment of iris melanoma

Iris melanoma is a rare form of uveal melanoma with potential metastic spread. Treatment options include surgical resection, enucleation or irradiation. We analysed visual outcome, complication appearance and management in eight patients with iris melanoma following robotic-assisted CyberKnife treatment. Consecutive patients from the Department of Ophthalmology at University of Munich were included in the study if they had an iris melanoma that was treated with CyberKnife and had a minimum follow-up of 12 months. We evaluated tumor thickness, largest diameter, visual acuity and complications. 8 patients were included in this report. The median age was 74 years (range: 53-86 years). The median follow-up was 23 months (range 12-48 months). Tumor thickness decreased from 2.1 to 1.4 mm on average. Four out of eight patients showed stable or increased visual acuity compared to visual acuity at first visit. We did not find a correlation of applied radiation volume or radiation dose on visual outcome. Radiation keratopathy was the most common complication in five patients. No recurrences were noted. Robotic-assisted radiosurgery following CyberKnife is a promising non-invasive, single session treatment option for iris melanoma with comparable results regarding recurrence rate or complications to brachytherapy and proton beam therapy. All included patients showed good visual outcome.

Low- and moderate-dose non-cancer effects of ionizing radiation in directly exposed individuals, especially circulatory and ocular diseases: a review of the epidemiology

PURPOSE

There are well-known correlations between high and moderate doses (>0.5 Gy) of ionizing radiation exposure and circulatory system damage, also between radiation and posterior subcapsular cataract. At lower dose correlations with circulatory disease are emerging in the Japanese atomic bomb survivors and in some occupationally exposed groups, and are still to some extent controversial. Heterogeneity in excess relative risks per unit dose in epidemiological studies at low (<0.1 Gy) and at low-moderate (>0.1 Gy, <0.5 Gy) doses may result from confounding and other types of bias, and effect modification by established risk factors. There is also accumulating evidence of excess cataract risks at lower dose and low dose rate in various cohorts. Other ocular endpoints, specifically glaucoma and macular degeneration have been little studied. In this paper, we review recent epidemiological findings, and also discuss some of the underlying radiobiology of these conditions. We briefly review some other types of mainly neurological nonmalignant disease in relation to radiation exposure.

CONCLUSIONS

We document statistically significant excess risk of the major types of circulatory disease, specifically ischemic heart disease and stroke, in moderate- or low-dose exposed groups, with some not altogether consistent evidence suggesting dose-response non-linearity, particularly for stroke. However, the patterns of risk reported are not straightforward. We also document evidence of excess risks at lower doses/dose-rates of posterior subcapsular and cortical cataract in the Chernobyl liquidators, US Radiologic Technologists and Russian Mayak nuclear workers, with fundamentally linear dose-response. Nuclear cataracts are less radiogenic. For other ocular endpoints, specifically glaucoma and macular degeneration there is very little evidence of effects at low doses; radiation-associated glaucoma has been documented only for doses >5 Gy, and so has the characteristics of a tissue reaction. There is some evidence of neurological detriment following low-moderate dose (∼0.1-0.2 Gy) radiation exposure in utero or in early childhood.

Plaque brachytherapy in iris and iridociliary melanoma: a systematic review of efficacy and complications

Purpose

To evaluate the efficacy and vision-threatening complication rate of plaque brachytherapy with iodine-125 (¹²⁵I), palladium-103 (¹⁰³Pd), and ruthenium-106 (¹⁰⁶Ru) for treatment of iris and iridociliary melanoma.

Material and methods

A literature review was done based on results yielded from searching PubMed, Embase, and Cochrane database, using following key words: iris melanoma, iridociliary melanoma, brachytherapy, iodine-125 brachytherapy, palladium-103 brachytherapy, and ruthenium-106 brachytherapy. Initially, relationships between mean radiation dose to apex and local recurrence and complication rate were analyzed, and then, a comparison was performed between ¹²⁵I, ¹⁰³Pd, and ¹⁰⁶Ru studies.

Results

Twelve retrospective and prospective studies were selected, with 491 patients treated primarily with plaque brachytherapy. The range of radiation dose to tumor apex were from 84 to 151.5 Gy. Ranges of mean and median of follow-up time were from 27 to 96 months. Local recurrence rate following brachytherapy ranged from 0 to 8%. A decrease in the average study dose was not associated with an increased local recurrence or metastasis rate (p = 0.373 and 0.195, respectively); however, an increase in radiation dose was associated with higher radiation-related cataract and glaucoma (p < 0.05). The rate of post-treatment glaucoma was higher in studies with ¹²⁵I plaque brachytherapy (p = 0.004).

Conclusions

For brachytherapy of iris and iridociliary melanoma, in a range of 84 to 150 Gy, an increase in radiation dose may increase the risk of complications, while the tumor control rate does not change.

Anterior Segment OCTA of Melanocytic Lesions of the Conjunctiva and Iris

PURPOSE

To study the feasibility and diagnostic value of vascular imaging using optical coherence tomography (OCT)-angiography (OCTA) of melanocytic lesions of the conjunctiva and iris.

DESIGN

Cross-sectional study.

METHODS

Twenty-five patients with an untreated conjunctival lesion (5 melanoma, 13 nevus, 7 primary acquired melanosis [PAM]) and 52 patients with an untreated iris lesion (10 melanoma, 42 nevus) were included. Patients were imaged using a commercially available OCTA device, with the addition of an anterior segment lens and manual focussing. Tumor vessel presence, vascular patterns and vascular density were assessed.

RESULTS

Good OCTA images were obtained in 18 of 25 conjunctival lesions and 42 of 52 iris lesions. Failure was caused by lack of patient cooperation, an unfavorable location, or mydriasis. In all imaged conjunctival lesions and 77% of iris lesions, vascular structures were detected. Conjunctival melanoma and nevi demonstrated the same intralesional tortuous patterns, whereas vasculature in eyes with PAM was similar to normal conjunctiva. Both iris melanoma and nevi demonstrated tortuous patterns, distinct from the radially oriented normal iris vasculature.

CONCLUSIONS

Optical coherence tomography angiography (OCTA) allows for noninvasive imaging of the vasculature in melanocytic lesions of the conjunctiva and iris. Good image quality depends highly on patient cooperation and lesion characteristics. Differentiation of benign and malignant lesions was not possible. New software is called for to improve image acquisition and analysis.

Iris Melanoma: Management and Prognosis

Iris melanomas represent 2–5% of uveal melanomas. Iris melanomas vary in their size, shape, degree of pigmentation and clinical behavior. The main local clinical complications of iris melanomas are tumor vascularization, ectropion uvea, pupillary distortion, pigment dispersion, sector cataract, chronic uveitis, hyphema and glaucoma with irreversible optic nerve damage. The most effective treatment for iris nevus and melanoma remains debatable; treatment modalities have been proposed depending on the local status as well as the age and general condition of the patient. A melanocytic iris nevus is usually observed until documented progression is identified. In this case, radiotherapy or surgical resection is generally performed. Cataract, glaucoma and limbal stem cell deficiency are usually secondary to radiotherapy, while incomplete tumor excisions, which could lead to recurrence, hemorrhage, vitreous loss, dislocated lens, iridocyclitis, macular edema, retinal detachment, glaucoma and cataract, are related to surgical resection. In some cases, a combination of radiotherapy and surgery is used. Conservative treatment is an efficient alternative to enucleation and allows good local tumor control.

Uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. UMs are usually initiated by a mutation in GNAQ or GNA11, unlike cutaneous melanomas, which usually harbour a BRAF or NRAS mutation. The annual incidence in Europe and the USA is ~6 per million population per year. Risk factors include fair skin, light-coloured eyes, congenital ocular melanocytosis, ocular melanocytoma and the BAP1-tumour predisposition syndrome. Ocular treatment aims at preserving the eye and useful vision and, if possible, preventing metastases. Enucleation has largely been superseded by various forms of radiotherapy, phototherapy and local tumour resection, often administered in combination. Ocular outcomes are best with small tumours not extending close to the optic disc and/or fovea. Almost 50% of patients develop metastatic disease, which usually involves the liver, and is usually fatal within 1 year. Although UM metastases are less responsive than cutaneous melanoma to chemotherapy or immune checkpoint inhibitors, encouraging results have been reported with partial hepatectomy for solitary metastases, with percutaneous hepatic perfusion with melphalan or with tebentafusp. Better insight into tumour immunology and metabolism may lead to new treatments.

[New treatment options for iridociliary tumors]

BACKGROUND

Benign iridal tumors rarely necessitate a therapeutic intervention. In contrast, malignant tumors of the iris can threaten the patient's life and eyesight and require early treatment to prevent the development of metastases.

OBJECTIVE

Presentation of current treatment options for iridal tumors with special emphasis on iridal melanoma.

METHODS

This article gives an overview of the current literature based on a PubMed search as well as own clinical experience.

RESULTS

Treatment options for iridal and ciliary body melanomas comprise radiotherapeutic and surgical (eyeball-sparing and non-sparing) approaches. The eyeball-sparing surgical procedure of choice is block excision. While local tumor control rates and metastasis rates of block excision and radiotherapy are comparable, there are distinct differences especially between the spectra of complications. New treatment procedures include immunomodulatory approaches and targeted therapies. Using checkpoint inhibitors, no convincing enhancement of overall survival could be demonstrated for metastatic iridal melanoma, as is the case for cutaneous melanoma. In contrast, tumor vaccination with the help of tumor RNA-laden patient-derived dendritic cells seems to be a promising option for a subgroup of high-risk patients. Targeted therapies aiming to suppress the MAPK and PI3K/Akt pathways could not achieve any improvement in patient survival.

CONCLUSION

For the primary treatment of iridal melanoma a surgical, eyeball-sparing approach and also when appropriate, radiotherapy can be recommended. In the future, eligible high-risk patients could profit from a tumor vaccination. To date, there is no effective systemic treatment for metastatic iridal melanoma.

Novel Eye Plaque Designs for Brachytherapy of Iris and Ciliary Body Melanoma and the First Clinical Application

Background

While traditional eye plaque brachytherapy can be used for the treatment of iris melanoma, it faces challenges of poor patient tolerability due to cornea-plaque touch caused by radius of curvature mismatch and potential dosimetric inaccuracy from incomplete coverage. We present novel plaque designs and the first clinical application of the plaques for iris melanoma.

Methods

Two dome-shaped plaques (EP2132 and EP1930) were designed to vault above the cornea to treat tumors of the iris and ciliary body. Image-based treatment planning of the first 2 clinical cases using the EP2132 plaque covered the tumor base plus a 2 mm margin and the involved ciliary body with at least 75 Gy to the tumor apex.

Results

The tumors decreased in size following treatment. The patients tolerated the treatment well. There was no adverse event associated with the traditional iris plaques, such as decreased vision, pain, corneal edema, glaucoma, or cataract.

Conclusion

The novel dome-shaped plaques for the treatment of iris melanoma provide effective dose distribution, improved surgical maneuverability, and increased tolerability for the patient. This plaque model can be used to treat iris melanoma of various sizes, configurations, and locations, including the ciliary body. The need for a customized plaque platform for each patient is minimized.

Occupational radiation exposure and glaucoma and macular degeneration in the US radiologic technologists

There are well-documented associations of glaucoma with high-dose radiation exposure, but only a single study suggesting risk of glaucoma, and less conclusively macular degeneration, associated with moderate-dose exposure. We assessed risk of glaucoma and macular degeneration associated with occupational eye-lens radiation dose, using participants from the US Radiologic Technologists Study, followed from the date of surveys in 1994-1998, 2003-2005 to the earliest of diagnosis of glaucoma or macular degeneration, cancer other than non-melanoma skin cancer, or date of last survey (2012-2014). We excluded those with baseline disease or previous radiotherapy history. Cox proportional hazards models with age as timescale were used. There were 1631 cases of newly self-reported doctor-diagnosed cases of glaucoma and 1331 of macular degeneration among 69,568 and 69,969 eligible subjects, respectively. Estimated mean cumulative eye-lens absorbed dose from occupational radiation exposures was 0.058 Gy. The excess relative risk/Gy for glaucoma was -0.57 (95% CI -1.46, 0.60, p = 0.304) and for macular degeneration was 0.32 (95% CI -0.32, 1.27, p = 0.381), suggesting that there is no appreciable risk for either endpoint associated with low-dose and low dose-rate radiation exposure. Since this is the first examination of glaucoma and macular degeneration associated with low-dose radiation exposure, this result needs to be replicated in other low-dose studies.

Iris Melanoma Outcomes Based on the American Joint Committee on Cancer Classification (Eighth Edition) in 432 Patients

PURPOSE

The American Joint Committee on Cancer (AJCC) classification was updated to the eighth edition in January 2017, providing staging for iris melanoma. This study evaluated outcomes of iris melanoma per the AJCC classification, eighth edition.

DESIGN

Retrospective case series.

PARTICIPANTS

Four hundred thirty-two patients with iris melanoma.

METHODS

Management including tumor resection, plaque radiotherapy, or enucleation.

MAIN OUTCOME MEASURES

Local tumor recurrence, melanoma-related systemic metastasis, and melanoma-related death.

RESULTS

Of 432 patients with iris melanoma, AJCC classification was category T1 (n = 324 [75%]), T2 (n = 83 [19%]), T3 (n = 2 [<1%]), and T4 (n = 23 [5%]). There was no difference in age, race, gender, eye, or iris color among T categories. Overall, Kaplan-Meier analysis of outcomes (at 5 and 10 years) revealed visual acuity reduction by 3 lines or more (42% and 54%, respectively), secondary glaucoma (29% and 33%, respectively), local recurrence (8% and 17%, respectively), secondary enucleation (12% and 19%, respectively), lymph node metastasis (1% and 1%, respectively), melanoma-related systemic metastasis (5% and 10%, respectively), and melanoma-related death (3% and 4%, respectively). Compared with T1 category, the hazard ratio (HR) for local recurrence in nonenucleated eyes was 1.31 for T2, not evaluable (NE) for T3 (because of small cohort), and 6.61 for T4; the HR for metastasis was 3.41 for T2, NE for T3 (because of small cohort), and 25.6 for T4; the HR for death was 7.51 for T2, NE for T3 (because of small cohort), and 26.5 for T4; and the odds ratio for enucleation was 1.23 for T2, 3.63 for T3, and 4.72 for T4. Features predictive of melanoma-related metastasis (multivariate analysis) included secondary glaucoma (P < 0.001; HR, 4.51), T2 category (vs. T1; P = 0.01; HR, 4.09), and T4 category (vs. T1; P < 0.001; HR, 30.8). Features predictive of melanoma-related death (multivariate analysis) included older age (P = 0.008; HR, 2.16 per 10-year increase), T2 category (vs. T1; P = 0.005; HR, 8.07), and T4 category (vs. T1; P < 0.001; HR, 20.3).

CONCLUSIONS

The AJCC eighth edition classification provides prognostic stratification of iris melanoma. By multivariate analysis, the ratio for melanoma-related metastasis was 4 times greater in category T2 and 31 times greater in T4 compared with T1. The ratio for melanoma-related death was 8 times greater in category T2 and 20 times greater in T4 compared with T1. The cohort size for T3 was too small to provide useful information.

Ruthenium-106 brachytherapy for iris and iridociliary melanomas

BACKGROUND AND PURPOSE

To evaluate ruthenium-106 (Ru106) brachytherapy as eye-conserving treatment of iris melanomas (IMs) and iridociliary melanomas (ICMs).

MATERIALS AND METHODS

Eighty-eight patients received Ru106 brachytherapy between 2006 and 2016. Primary outcome was local control, and secondary outcomes were metastasis, survival, eye preservation, complications and visual acuity (VA).

RESULTS

Overall median follow-up was 36 months. Of 88 patients, 58 (65.9%) had IM and 30 (34.1%) had ICM. ICM were on average larger and more advanced than IM. Local failure-free survival at 3years was 98.9% (SE 1.2%). Metastasis-free survival was 98.2% (SE 1.8%) at 3years; no deaths due to melanoma occurred during follow-up. Eye preservation rate was 97.7%. Treatment-related toxicities were mostly mild and observed in 80.7% of the patients. Common toxicities were worsening of pre-existing or new cataract (51.1%), dry eyes (29.5%) and glaucoma (20.5%). VA was not affected by Ru106 brachytherapy, with only 2.3% having VA <0.33 (low vision) at follow-up.

CONCLUSIONS

Ru106 for IM and ICM yielded excellent local control (98.9%) and eye preservation (97.7%). Toxicities were common, but mostly mild and transient. Moreover, Ru106 did not affect visual acuity.

Orbital recurrence of iris melanoma 21 years after enucleation

We present the case of a 56-year-old man who developed a neoplasm of epithelioid histology in his anophthalmic left orbit 21 years after he underwent enucleation for a spindle cell iris melanoma. The recurrent tumour was managed by orbital exenteration. Neither further recurrence nor metastasis was diagnosed over a 5-year follow-up period. This case, along with five other similar cases in the literature,^1-3 emphasises the importance of long-term follow-up after treatment of iris melanoma.

Late Solitary Extraocular Recurrence From Previously Resected Iris Melanoma

PURPOSE

To report on cases of late extraocular relapse of previously resected iris melanoma, without concurrent intraocular recurrence.

DESIGN

Retrospective case series.

METHODS

A retrospective chart review of 4 patients diagnosed with late subconjunctival relapse of previously resected iris melanoma.

RESULTS

Three female patients and 1 male patient underwent iris tumor resection and presented to our service with suspicious conjunctival lesions at a median of 22 years later (mean: 21 years). None showed intraocular relapse. Treatment of the conjunctival tumors included excisional biopsy (n = 4), followed by cryotherapy (n = 3) and/or brachytherapy (n = 3). In all cases, histopathology confirmed malignant melanoma, with no intraepithelial component or associated melanosis. Genetic sequencing (n = 3) showed wild-type BRAF and NRAS in all. GNA11 mutation was found in 1 case. On array-based comparative genomic hybridization (n = 3), gain of 6p was found in 2 cases and gain of 8 in 2. Overall, findings were strongly suggestive of a diagnosis of late extraocular relapse from previously resected iris melanoma. In a median of 2.5 years (mean: 7.7 years) from the subconjunctival relapse, no further episodes of intraocular/extraocular recurrence were recorded, and all patients were free from distant metastasis.

CONCLUSIONS

Patients undergoing iris melanoma resection are at risk of developing late solitary extraocular relapse even more than 30 years after surgery. In the absence of an intraocular component, diagnosis may be challenging, as tumors mimic a primary conjunctival lesion. Management by excisional biopsy followed by adjuvant therapy was successful, and histopathology and genetic analysis supported a diagnosis of extraocular uveal tumor spread rather than a primary conjunctival tumor.

Use of Ruthenium-106 Brachytherapy for Iris Melanoma: The Scottish Experience

PURPOSE

To analyse long-term outcomes of ruthenium-106 (¹⁰⁶Ru) plaque brachytherapy for the treatment of iris melanoma.

METHODS

We retrospectively reviewed medical records of 19 consecutive patients with pure iris melanoma treated with ¹⁰⁶Ru plaque brachytherapy between 1998 and 2016 at the Scottish Ophthalmic Oncology Service, Glasgow. The iris melanoma was treated with a ruthenium plaque placed on the corneal surface to deliver a surface dose of 555 Gy. We analysed vision preservation, local tumour control, radiation-related complications, eye retention rates, symptomatic metastasis and melanoma-related mortality.

RESULTS

The mean largest basal diameter of the lesions was 3.50±1.42 mm (range 1.6-6.5 mm), and the mean maximum height was 1.47±0.65 mm (range 0.7-2.8 mm). The tumour control and eye retention were 100% at a mean follow-up of 62 months (range 6-195 months). A 62% reduction in tumour height was observed on ultrasonography. Complications included cataract (68%), dry eye (47%), uveitis (37%) and scleral thinning (5%). At the final follow-up visit, the mean loss of Snellen visual acuity was 1.11±2.90 lines and vision of 6/9 or better was maintained in 53% of patients. None of the patients had evidence of symptomatic metastasis (non-imaged) or melanoma-related mortality.

CONCLUSIONS

¹⁰⁶Ru plaque treatment for iris melanoma was highly effective a high tumour control, no tumour recurrences and a relatively a low complication rate.