Cell proliferation activity in posterior uveal melanoma after Ru-106 brachytherapy: an EORTC ocular oncology group study

Description and Characteristics of Ocular Tumor Lysis Syndrome

Introduction

The aim of the study was to describe and evaluate characteristics of ocular tumor lysis syndrome (OTLS) in eyes with uveal melanoma.

Methods

Retrospective chart review of all patients with OTLS at the University of Colorado from 2009 to 2021. Data collected included patient demographics, tumor characteristics, radiation dosimetry, gene expression profiling (GEP), OTLS characteristics, management, and outcomes.

Results

Seven eyes of seven patients with uveal melanoma treated with I-125 brachytherapy developed OTLS. Average age was 59 years (range 32-83). Mean apical height was 8.6 mm (range 6-11); mean diameter was 12.7 mm (range 8.5-15.3). All tumors were treated with plaques ≥16 mm in diameter. On presentation, 5/7 tumors had subretinal fluid, and 6/7 had collar-button configuration. OTLS presented as extensive pigment dispersion in the vitreous in all eyes, subretinal pigment and/or retinal detachment in 4/7 eyes, vitreous hemorrhage in 2/7 eyes, and anterior chamber pigment in 3/7 eyes. Four tumors were GEP class 1, two were class 2, and one was unclassified. Biopsy route was trans-scleral in 4/7 eyes and trans-vitreal in 3/7 eyes. OTLS occurred 2-4 weeks after an intraocular procedure in 5/7 eyes. All underwent pars plana vitrectomy. Cytology of the vitreous, obtained in five cases, showed pigment laden macrophages and hemorrhage, but only 1/5 eyes had viable malignant cells. Four eyes were stable at the last follow-up, two were enucleated, and one had no light perception from pigmentary glaucoma. Poor vision (<20/200) occurred in 6/7 cases. Three patients died from metastasis (tumors were GEP class 2, GEP class without subclassification, and no GEP classification performed).

Conclusions

OTLS is a rare but devastating complication of uveal melanoma. Common characteristics included large plaque diameter, presence of subretinal fluid, and collar-button shape. The extensively dispersed pigment is typically not malignant. Though poor vision is common, enucleation may be avoided in most eyes through vitreoretinal surgical repair.

Photodynamic therapy (PDT) as adjuvant treatment to brachytherapy for amelanotic choroidal melanoma

PURPOSE

To evaluate the effect of photodynamic therapy (PDT) as adjuvant treatment, after brachytherapy, in posterior amelanotic choroidal melanomas.

METHODS

Six patients with posterior amelanotic choroidal melanoma underwent brachytherapy treatment. Tumour response was assessed by fundus examination, fundus photography and A-B scan ultrasonography. The residual tumours were treated with adjuvant PDT performed with infusion of verteporfin intravenously at 6 mg/m2 body surface area. Five minutes after infusion, a 689 nm laser was applied with a light dose of 100 J/cm2 over an interval of 166 s.

RESULTS

At a median follow-up after brachytherapy of 17.5 months (IQR 16.2-22.5, range 5-42 months), tumours showed a partial reduction of tumour thickness (22.5% as compared to baseline value) and persistent low internal reflectivity at A-B scan ultrasonography. Supplementary photodynamic treatment resulted in complete resolution of the lesion with marked decrease of elevation . Mean decrease in thickness after PDT was 49.9% with respect to previous brachytherapy treatment 22.5% (p = 0.007). The results was achieved within a median period of 4 months (range 2-4 months) after PDT, and there has been no recurrence after a median follow-up of 84.7 months ± 18.7 (range 59 to 107 months).

CONCLUSION

Combined treatment of brachytherapy and adjuvant PDT in amelanotic uveal melanoma seems to be favourable with regard to complete and rapid tumour regression.

Metastatic uveal melanoma: The final frontier

Treatment of primary intraocular uveal melanoma has developed considerably, its driver genes are largely unraveled, and the ways to assess its risk for metastases are very precise, being based on an international staging system and genetic data. Unfortunately, the risk of distant metastases, which emerge in approximately one half of all patients, is unaltered. Metastases are the leading single cause of death after uveal melanoma is diagnosed, yet no consensus exists regarding surveillance, staging, and treatment of disseminated disease, and survival has not improved until recently. The final frontier in conquering uveal melanoma lies in solving these issues to cure metastatic disease. Most studies on metastatic uveal melanoma are small, uncontrolled, retrospective, and do not report staging. Meta-analyses confirm a median overall survival of 10-13 months, and a cure rate that approaches nil, although survival exceeding 5 years is possible, estimated 2% either with first-line treatment or with best supportive care. Hepatic ultrasonography and magnetic resonance imaging as surveillance methods have a sensitivity of 95-100% and 83-100%, respectively, to detect metastases without radiation hazard according to prevailing evidence, but computed tomography is necessary for staging. No blood-based tests additional to liver function tests are generally accepted. Three validated staging systems predict, each in defined situations, overall survival after metastasis. Their essential components include measures of tumor burden, liver function, and performance status or metastasis free interval. Age and gender may additionally influence survival. Exceptional mutational events in metastases may make them susceptible to checkpoint inhibitors. In a large meta-analysis, surgical treatment was associated with 6 months longer median overall survival as compared to conventional chemotherapy and, recently, tebentafusp as first-line treatment at the first interim analysis of a randomized phase III trial likewise provided a 6 months longer median overall survival compared to investigator's choice, mostly pembrolizumab; these treatments currently apply to selected patients. Promoting dormancy of micrometastases, harmonizing surveillance protocols, promoting staging, identifying predictive factors, initiating controlled clinical trials, and standardizing reporting will be critical steppingstones in reaching the final frontier of curing metastatic uveal melanoma.

[Local treatment of choroidal melanoma: possibilities and limitations]

Local treatment of choroidal melanoma (CM) attracts the attention of many ophthalmology specialists, especially in recent years as the capabilities to target irradiation at small objects and possibilities of surgical interventions on the eyeball have expanded. The article discusses the medical indications for local treatment of CM. Review of literature of the last 16 years and author's own observations on CM patients who underwent almost all kinds of conventional methods of local treatment allowed thorough analysis of indications and counter-indications for their usage. Among the authors who favor local destruction and removal of large CM, the main indication is the possibility to preserve vision and anatomical structures of the eye. This led to unreasonably wide spread of local destruction (removal) of large CM, primarily the endovitreal resection method. However, such metastasis risk factors as CM size and its localization are being overlooked. Literature analysis and author's own observations helped validate the unsafety of the local treatment of large CM. The article features long-term results of contact and distant radiation therapy, and presents CM metrics for best therapeutic effect.

Histopathologic Patterns of Recurrent Choroidal Melanoma Following I-125 Plaque Brachytherapy

Purpose

Histologic correlation of clinical patterns of recurrent choroidal melanoma following I-125 plaque brachytherapy was performed to identify pathologic mechanisms of recurrence.

Methods

We reviewed 7 cases of recurrent choroidal melanoma following I-125 plaque brachytherapy managed with enucleation. Clinical characteristics included tumor dimensions, radiation dose, time to local recurrence, and clinical pattern of recurrence. Histopathology (hematoxylin and eosin and periodic acid - Schiff) and immunohistochemistry (Ki-67, CD-163, HMB45, and SOX10) were performed.

Results

Mean follow-up time and time to local recurrence were 42 and 21 months after brachytherapy, respectively. Tumor recurrences were described clinically as marginal in 43%, diffuse in 29%, and extraocular extension (EOE) in 29%. Eighty-six percent were classified as mixed cell type and 14% were epithelioid type. Tumor zonation (histologic demarcation between zones of recurrent and nonrecurrent tumor cells by immunohistochemistry) was present in marginal and EOE cases (n = 6) and absent in the diffuse cases (n = 2). Ki-67 proliferative index was higher in marginal and EOE recurrences, while diffuse cases showed uniform -Ki-67 staining. CD-163 staining was found to be greater in nonrecurrent tumor. HMB45 correlated with SOX10 with a greater staining in recurrent tumor.

Conclusion

Our observations provide a correlation between histopathologic and clinical patterns of local recurrence of choroidal melanoma after brachytherapy.

Clinical and histopathological features of choroidal melanoma-related enucleated eyes in a Spanish tertiary hospital

OBJECTIVE

To study clinical and pathological variables leading to a poor prognosis in a sample of uveal malignant melanoma patients who required eyeball enucleation as final treatment approach. All patients were seen and treated in the same public tertiary hospital in Madrid (Spain) within a 6-year time-period.

MATERIALS AND METHODS

Longitudinal observational retrospective study. The presence of clinical and pathologic factors known to be linked to poor prognosis, as well as other features, was assessed in 30 malignant melanoma: 20 de novo-enucleated malignant melanoma eyes (group A), and 10 in eyes that received radiotherapy prior to enucleation (group B). The diagnostic reliability of magnetic resonance imaging was assessed by comparing it with the histology results (gold standard) as a means to detect scleral and extra-scleral extension.

RESULTS

Tumour size, Bruch's membrane rupture, scleral infiltration, and distance to the optic nerve were the most decisive factors for a poor prognosis in the study sample. In 93% of cases the condition was under control, with a 6% incidence rate of metastatic spread and a 100% rate of overall survival for a mean follow-up period of 3±1.5 (range 1.2-6) years. In the study population, the sensitivity of the magnetic resonance imaging to detect scleral infiltration was 27%, which increased to 100% for identifying extra-scleral involvement.

CONCLUSIONS

The analyses of the clinical and pathological data collected within the framework of this study justify enucleation as the treatment of choice for the patients of this study. Magnetic resonance imaging was not found to be an optimum screening method to detect scleral infiltration in this study sample.

Uveal melanoma: estimating prognosis

Uveal melanoma is the most common primary malignant tumor of the eye in adults, predominantly found in Caucasians. Local tumor control of uveal melanoma is excellent, yet this malignancy is associated with relatively high mortality secondary to metastasis. Various clinical, histopathological, cytogenetic features and gene expression features help in estimating the prognosis of uveal melanoma. The clinical features associated with poor prognosis in patients with uveal melanoma include older age at presentation, male gender, larger tumor basal diameter and thickness, ciliary body location, diffuse tumor configuration, association with ocular/oculodermal melanocytosis, extraocular tumor extension, and advanced tumor staging by American Joint Committee on Cancer classification. Histopathological features suggestive of poor prognosis include epithelioid cell type, high mitotic activity, higher values of mean diameter of ten largest nucleoli, higher microvascular density, extravascular matrix patterns, tumor-infiltrating lymphocytes, tumor-infiltrating macrophages, higher expression of insulin-like growth factor-1 receptor, and higher expression of human leukocyte antigen Class I and II. Monosomy 3, 1p loss, 6q loss, and 8q and those classified as Class II by gene expression are predictive of poor prognosis of uveal melanoma. In this review, we discuss the prognostic factors of uveal melanoma. A database search was performed on PubMed, using the terms “uvea,” “iris,” “ciliary body,” “choroid,” “melanoma,” “uveal melanoma” and “prognosis,” “metastasis,” “genetic testing,” “gene expression profiling.” Relevant English language articles were extracted, reviewed, and referenced appropriately.

Management of uveal melanoma: a consensus-based provincial clinical practice guideline

INTRODUCTION

Survival in uveal melanoma has remained unchanged since the early 1970s. Because outcomes are highly related to the size of the tumour, timely and accurate diagnosis can increase the chance for cure.

METHODS

A consensus-based guideline was developed to inform practitioners. PubMed was searched for publications related to this topic. Reference lists of key publications were hand-searched. The National Guidelines Clearinghouse and individual guideline organizations were searched for relevant guidelines. Consensus discussions by a group of content experts from medical, radiation, and surgical oncology were used to formulate the recommendations.

RESULTS

Eighty-four publications, including five existing guidelines, formed the evidence base.

SUMMARY

Key recommendations highlight that, for uveal melanoma and its indeterminate melanocytic lesions in the uveal tract, management is complex and requires experienced specialists with training in ophthalmologic oncology. Staging examinations include serum and radiologic investigations. Large lesions are still most often treated with enucleation, and yet radiotherapy is the most common treatment for tumours that qualify. Adjuvant therapy has yet to demonstrate efficacy in reducing the risk of metastasis, and no systemic therapy clearly improves outcomes in metastatic disease. Where available, enrolment in clinical trials is encouraged for patients with metastatic disease. Highly selected patients might benefit from surgical resection of liver metastases.

KI-67 Immunopositivity in Choroidal and Ciliary Body Melanoma with Respect to Nucleolar Diameter and Other Prognostic Factors

PURPOSE

To study the association of cell proliferation in uveal melanoma with the mean of the 10 largest nucleoli (MLN), microvascular prognostic factors, and survival.

METHODS

Population-based, retrospective cohort study of 167 choroidal and ciliary body melanomas enucleated from 1972 to 1981. Mouse monoclonal antibody Ki-67 (clone 7B11) was used to identify proliferating cells. MLN was measured from silver stained slides. Kaplan-Meier and Cox regression analysis were performed.

RESULTS

The median number of Ki-67 immunopositive cells was 8 per tumor cross-section (range, 0-272) corresponding to a median of 0.30 cells/mm2. The percentage of immunopositive cells was 0.02% of all cells (range, 0-3.2). Tumors with epithelioid cells tended to have a higher percentage of immunopositive cells (p = 0.089). Ki-67 immunoreactivity, MLN, and presence of extravascular loops and networks were independent predictors of melanoma-related mortality, whereas Ki-67 immunoreactivity was not an independent predictor of mortality when presence of epithelioid cells was in the model.

CONCLUSIONS

Taken together with previous data, the results of this population-based study support the theory that high cell proliferation index is associated with presence of epithelioid cells and that presence of a high cell proliferation index is associated with a higher risk of metastatic death independent of MLN, microvascular density, and presence extravascular loops and networks.

Inhibitor of apoptosis proteins gene expression and its correlation with prognostic factors in primary and metastatic uveal melanoma

PURPOSE

Members of the inhibitors of apoptosis proteins (IAPs) family are thought to promote tumor growth and interfere with response to therapy by suppressing apoptosis in several malignancies. We aimed to evaluate the expression of IAPs in uveal melanoma (UM) and its correlation with prognostic factors associated with death from metastatic UM.

METHODS

Expression of eight IAP genes [Baculoviral IAP repeat-containing (BIRC) 1-8] was evaluated through reverse transcription (RT)-PCR. BIRC5 and BIRC7 expression was measured using quantitative PCR (QPCR). BIRC5 protein expression was assessed with immunohistochemistry. QPCR results were correlated with apoptosis rate and with prognostic factors in UM, including lesion dimensions, cell type, monosomy 3, and vascular mimicry patterns.

RESULTS

IAP genes were expressed in the majority of primary and metastatic UM. BIRC5 and BIRC7 levels were 8.8-fold (p = 0.0003) and 7.0-fold (p = 0.003) higher in tumors (primary and metastatic tissue) vs. normal eye tissue, respectively. BIRC5 levels correlated with presence of monosomy 3 (p = 0.01) and higher levels of BIRC7 correlated with epithelioid cell type (p = 0.048).

CONCLUSIONS

IAPs expression is up regulated in UM and is associated with some of its prognostic factors. Considering our findings together with previous reports on their role in a variety of malignancies and in UM cell lines, it is conceivable that IAPs contribute to the remarkable resistance of uveal melanoma to apoptosis-inducing chemotherapy.

Triamcinolone acetonide and anecortave acetate do not stimulate uveal melanoma cell growth

PURPOSE

Radiotherapy-induced radiation retinopathy can develop in over 40% of eyes treated for uveal melanoma. Triamcinolone acetonide (TA) and anecortave acetate (AA) can be used to treat radiation retinopathy. It is not known whether TA or AA has any effect on potentially still viable uveal melanoma cells in the choroid after radiotherapy. We therefore studied the effect of these drugs on the proliferation of uveal melanoma cell lines in vitro. Furthermore, as these drugs are supposed to counteract vascular leakage, we determined their effect on the expression and production of the proangiogenic vascular endothelial growth factor-A (VEGF-A), the antiangiogenic pigment epithelium-derived factor (PEDF), and thrombospondin-1 (TSP-1) in uveal melanoma cells.

METHODS

Three uveal melanoma cell lines were treated in vitro with TA or AA. Cell proliferation was measured by counting cells and using the Water-Soluble Tetrazolium Salt-1 (WST-1) assay. VEGF-A and PEDF production was measured by ELISA, and intracellular expression of angiogenic-associated genes including VEGF-A, PEDF, and TSP-1 was determined by real-time quantitative RT-PCR.

RESULTS

We found no effect of TA or AA on tumor cell growth or production of VEGF-A and PEDF in any of the three uveal melanoma cell lines tested. Regarding expression as measured by RT-PCR, TA had an inhibiting effect on TSP-1 in only one cell line, and no effect on VEGF-A or PEDF. AA showed a similar lack of effect.

CONCLUSIONS

Since TA and AA do not stimulate uveal melanoma cell growth, it seems to be safe to use these drugs to treat radiation retinopathy after irradiation for uveal melanoma. Additional experiments using more cell lines or primary tumor cell cultures are needed to validate this conclusion. Furthermore, the results of our study suggest that TA does not exert its antileakage effect through downregulation of VEGF-A or upregulation of TSP-1 or PEDF in uveal melanoma cell lines. It is possible that TA and AA influence these pro- and antiangiogenic factors only under hypoxic circumstances. Further investigation is needed.

Cyclooxygenase-2 expression in human irradiated uveal melanomas

AIM

Previous studies have shown that radiotherapy is a stimulus for cyclooxygenase-2 (COX-2) expression and that use of COX-2 inhibitors enhances the radio sensitivity of tumor cells. The objective of this study was to evaluate COX-2 expression, and its correlation with tumor regrowth after irradiation, in enucleated eyes with uveal melanomas.

METHODS

Fifteen tissue samples from patients who underwent enucleation after radiotherapy between 1988 and 2001 were used. Nine cases (60%) were enucleated because of tumor regrowth and six (40%) because of severe complications of radiotherapy. Specimens were immunostained for COX-2, and tumor cells were evaluated for specific cytoplasmic and granular immunostaining. COX-2 expression for these cases was compared with that in the previous study including 40 non-irradiated uveal melanoma cases. COX-2 expression was also correlated with tumor regrowth after radiotherapy.

RESULTS

Two cases (13.3%) were positive and thirteen (86.7%) were negative for COX-2 expression. One of the positive cases had been enucleated because of tumor regrowth and one because of radiotherapy complications. There was no relationship between tumor regrowth and COX-2 expression. COX-2 expression was significantly lower in irradiated cases than in non-irradiated cases in the previous study (p<0.001).

CONCLUSIONS

In contrast with studies showing an increase of COX-2 expression in other irradiated malignancies, irradiation was not a factor inducing COX-2 in uveal melanomas. Radiotherapy may, moreover, be a factor that reduces COX-2 expression in uveal melanomas.

[Macroscopic and histological data in the prognosis of malignant choroidal melanoma]

The macroscopic study of choroidal melanoma gives information on tumor extension and tumor size, which help in determining the prognosis and in making the therapeutic choice. Numerous microscopic changes observed in melanomas are also important in the prognosis. However, the number of available histologic specimens has dramatically decreased since the generalized use of conservative radiation treatment. Except in cases of enucleation or choroidectomy, the histologic criteria to establish the prognosis are not available in many cases and cannot be used for wide-range statistical studies.

Apoptosis inhibitor, survivin, in posterior uveal melanoma: comparison among primary tumors, tumors resistant to brachytherapy, tumors with liver metastases, and liver metastases

PURPOSE

To study the expression of survivin, an apoptosis inhibitor protein, in human posterior uveal melanoma.

METHODS

Specimens were divided according to eyes with tumors that were enucleated primarily, those resistant to brachytherapy, eyes from patients with known liver metastases, and liver metastases.

RESULTS

There was only low expression of survivin in uveal melanoma. No difference in survivin positive cell counts per high power field (PCC/HPF) were found among tumors that were enucleated primarily (n = 33), tumors with previous brachytherapy (n = 29), tumors with liver metastases (n = 12) or liver metastases (n = 18). Corresponding counts were 11.8 (+/-14.3), 11.8 (+/-16.8), 7.1 (+/-11.2), and 4.7 (+/-8.8) in the four groups, respectively (p > 0.05). Half of the liver metastases showed no staining for survivin. Twenty patients (24%) had tumor-related death at the end of follow-up.

CONCLUSIONS

Survivin is expressed in posterior uveal melanomas that were treated by enucleation, as well as in tumors that were previously treated with brachytherapy or liver metastases; however, its expression by immunostaining did not seem with correlate with the tumor biological activity.

Pigmented Episcleral Deposits after Brachytherapy of Uveal Melanoma

PURPOSE

To describe the characteristics and evolution of pigmented episcleral deposits after brachytherapy for uveal melanoma to determine their origin and association with melanoma-related mortality.

DESIGN

Noncomparative case series.

PARTICIPANTS

Two hundred eleven patients (108 males, 103 females; median age, 61 years; range, 14-88 years) who were treated with a single ruthenium and iodine plaque therapy (median dose to tumor base, 475 Gy and 392 Gy, respectively) for a choroidal and ciliary body melanoma. Median tumor diameter and height were 12 mm and 5.5 mm, respectively. Eighty-eight patients were treated prospectively during the study.

METHODS

The number and location of pigmented episcleral deposits were recorded under the slit lamp during each visit after brachytherapy. The association of the deposits with tumor characteristics and survival was analyzed with logistic regression and Kaplan-Meier analysis, respectively.

MAIN OUTCOME MEASURES

Number and location of episcleral deposits, melanoma-related mortality.

RESULTS

The pigmented episcleral deposits ranged from black and brownish spots to slightly thickened patches. Most deposits appeared within the first 6 months after brachytherapy. By 1 year, 85% (95% confidence interval, 77-93) of eyes had at least 1 deposit (median, 6). The deposits increased in number until 7 years from irradiation, and decreased with increasing distance from tumor center. An association between the number of deposits at 1 and 2 years and subsequent melanoma-related mortality could not be confirmed (P = 0.80 and P = 0.31, respectively).

CONCLUSIONS

Pigmented macrophage-related episcleral deposits are found in most eyes with uveal melanoma after brachytherapy. Their association with plaque size and isotope rather than with tumor size suggests that radiation atrophy of retinal pigment epithelium and choroid in addition to tumor regression contributes to the formation of the deposits. Knowledge of their existence may save patients from unnecessary enucleation.

18 years' experience with high dose rate strontium-90 brachytherapy of small to medium sized posterior uveal melanoma

AIM

To analyse local tumour control, radiation related complications, visual acuity, enucleation rate, and survival after brachytherapy of small to medium sized choroidal melanoma (CM) with a high dose rate (HDR) strontium-90 (Sr-90) applicator.

METHODS

From 1983 until 2000, 98 eyes with CM were treated with Sr-90 brachytherapy. The main outcome measures were actuarial rates of the patients' survival, ocular conservation rate, tumour regression, complication rates, and preservation of visual acuity. End point rates were estimated using Kaplan-Meier analysis.

RESULTS

The median follow up time was 6.7 years (0.5-18.8 years). Actuarial melanoma free patient survival rate was 85% (SE 4.8%) after 18 years. Actuarial rate of ocular conservation and complete tumour regression was 90% (SE 3.8%) after 15 years. In 93% local tumour control was achieved, 88% showed a stable scar. Recurrence of the tumour on the border caused enucleation of six eyes (7%). In three cases (4%) retinal detachment was the end point. No cases of optic atrophy or of sight impairing retinopathy outside the treated area were found. Actuarial rate of preservation of visual acuity of 1/10 was 65% at 5 years and 45% at 15 years of follow up (SE 5.9% and 8.8%).

CONCLUSIONS

Sr-90 brachytherapy is as effective as iodine or ruthenium brachytherapy for small to medium sized CM but causes fewer complications. The preservation of vision is better than with all other described radioisotopes. HDR Sr-90 brachytherapy can therefore safely be recommended for small to medium sized CM.

Proton beam therapy and iris neovascularisation in uveal melanoma

PURPOSE

Local treatment of uveal melanoma by radiotherapy involves the use of brachytherapy with radioactive plaques attached to the sclera, or proton irradiation. Both treatments induce growth arrest within the tumour and its slow involution over several years. Although ocular retention rates are excellent, regrowth of tumours due to resistance and neovascular glaucoma leads to enucleation of up to 10% of affected eyes. Proton irradiation involves part of the iris in most cases and we noticed that neovascularisation only occurred in the part of the iris that was not irradiated. We therefore conducted this study to determine the relationship between the development of iris neovascularisation and iris irradiation.

METHODS

A total of 21 enucleation specimens from patients who had previously had proton irradiation were collected from the files of the Department of Pathology, Moorfields Eye Hospital during the 5-year period from 1994 to 1999. Sections of these eyes were assessed for VEGF-A, bFGF, and von Willebrand Factor (vWF) by immunohistochemistry. Ophthalmic notes and radiotherapy records were reviewed to assess the extent of iris irradiation.

RESULTS

In all, 11 cases showed clinical evidence of iris neovascularisation and were selected for further study. Three of these eyes also showed clinical evidence of regrowth of the tumour. Histological evidence of iris neovascularization was noted in all 11 of the eyes examined, and was only present in the nonirradiated side of the iris in 8/11 eyes. NVI was present on both sides of the iris in three cases, but was less severe in the irradiated part. Expression of VEGF-A was at most weak within the tumour, but was present in the detached retina and in the epithelium of both ciliary body and iris. Some bFGF staining was noted around vessels in the iris stroma.

CONCLUSIONS

Our results suggest that irradiation leads to iris atrophy, and that atrophic, irradiated iris is resistant to the development of neovascularisation.

Treatment options for choroidal malignant melanoma: a case report featuring transpupillary thermotherapy

BACKGROUND

Choroidal melanoma is the most common primary ocular tumor in adults. These tumors are almost always unilateral and develop spontaneously or arise from pre-existing nevi. Historically, treatment for choroidal melanoma was enucleation. New therapies have been developed to treat choroidal melanoma and to preserve the eye. Currently, these treatment options include brachytherapy and transpupillary thermotherapy.

CASE REPORT

A 51-year-old man came to the eye clinic with symptoms of mildly decreased fluctuating vision and floaters with no flashes in the temporal visual field of the right eye. Best-corrected visual acuities were 20/30 O.D. and 20/20 O.S. A small-to-medium choroidal lesion was found in the right eye. Ultrasonography and A-scan showed this lesion to be a choroidal malignant melanoma. The patient's surgical options included enucleation, brachytherapy, and transpupillary thermotherapy. The patient opted to have transpupillary thermotherapy to preserve the eye, and subsequently underwent two procedures that eventually obliterated the melanoma, resulting in best-corrected visual acuity of 20/40.

CONCLUSION

Transpupillary thermotherapy is an excellent option for treatment of small-to-medium choroidal melanomas. Brachytherapy is also an option for treatment, but with increased ocular side effects and complications. Enucleation is still commonly performed on medium and/or large choroidal melanomas.

Macrophages and microcirculation in regressed and partially regressed irradiated choroidal and ciliary body melanomas

PURPOSE

To investigate how tumour-infiltrating macrophages and microcirculation attributes of uveal melanomas regressed after brachytherapy and whether primarily enucleated melanomas differ.

METHODS

A case-control analysis of 34 matched pairs of irradiated and nonirradiated choroidal and ciliary body melanomas with main outcome variables being area of necrosis, extravascular matrix loops and networks, tumour-infiltrating macrophages in nonnecrotic areas identified with mAb PG-M1 to the CD68 epitope, and microvascular density (MVD) determined by mAb QBEND/10 to the CD34 epitope.

RESULTS

Comparison of primarily enucleated eyes to eyes with irradiated, secondarily enucleated melanomas revealed significantly more necrosis (median difference, +9%, P = 0.0012) and lower MVD (median difference, -10 counts/0.313 mm(2), P = 0.011) in the latter. In eyes managed with brachytherapy, loops and networks tended to be less frequent (P = 0.077). Number and type of macrophages were similarly distributed, being moderate to high in about 95% (P = 0.67) of the matched pairs, and intermediate to dendritic in 79% (P = 0.90). In the irradiated eyes, presence of epithelioid cells and the number and type of macrophages showed no association with microcirculation attributes, whereas in the primarily enucleated tumours, high number of macrophages was associated with high MVD (P < 0.001).

CONCLUSIONS

This study suggests that regression after brachytherapy reduces MVD. The difference cannot be attributed to different numbers of tumour-infiltrating macrophages and different cell type in nonnecrotic areas of the tumour.

Combined plaque radiotherapy and transpupillary thermotherapy in choroidal melanoma: 5 years' experience

AIM

To evaluate the results of combined plaque radiotherapy and transpupillary thermotherapy (TTT) in 50 consecutive patients 5 years after treatment.

METHODS

50 adult patients with choroidal melanoma were treated with ruthenium-106 ((106)Ru) plaque radiotherapy combined with TTT. A flat scar was the preferred end point of treatment. The mean tumour thickness was 3.9 mm (range 1.5-8.0 mm), the mean tumour diameter was 11.3 mm (range 5.8-15.0 mm). TTT was performed with an infrared diode laser at 810 nm, a beam diameter of 2-3 mm, and 1 minute exposures. Tumours >5 mm thick received an episcleral contact dose of 800 Gy (106)Ru; tumours <or=5 mm thick received a contact dose of 600 Gy (106)Ru. TTT was repeated in case of incomplete tumour regression after combined therapy.

RESULTS

Complete tumour regression was obtained in 45 patients. It required one, two, or three TTT sessions in 32, 11, and two patients, respectively. In tumours <or=3 mm thick complete flattening was achieved significantly faster than in tumours >3 mm thick (log rank test p = 0.01). Eight melanomas were amelanotic, seven of which required multiple TTT sessions. In one patient the tumour recurred at the central margin of the treated area; this eye was enucleated. In one patient the tumour failed to regress 6 months after treatment and enucleation was performed at the patient's request. Three eyes developed severe proliferative retinopathy. Radiation maculopathy caused a loss of the best corrected visual acuity: before treatment 31 patients had a best corrected visual acuity of 20/60 or better but in only 12 patients did it remain in this range 5 years after treatment. Three patients developed distant metastasis to the liver.

CONCLUSION

The 5 year results for combined plaque radiotherapy and TTT as treatment for choroidal melanoma are favourable in terms of complete tumour regression and low rate of recurrences; however, there was considerable loss of visual acuity as a result of radiation maculopathy.

Expression of the c-kit receptor in choroidal melanomas

The KIT gene encodes c-kit, a transmembrane receptor that has tyrosine kinase activity and plays a role in haematopoiesis, gametogenesis and melanogenesis. The c-kit protein is found in normal cutaneous and choroidal melanocytes, and there is evidence that expression is lost in melanoma. Expression of c-kit was analysed in 57 paraffin-embedded sections of choroidal melanoma specimens and three choroidal melanoma cell lines using immunochemistry and Western blotting. Of the tumour specimens, 75% stained positively for c-kit with a membrane pattern of reactivity. Of the six patients who underwent proton beam therapy before enucleation, five tumours exhibited no c-kit immunoreactivity and the other tumour demonstrated weak staining. Of the three melanoma cell lines used, c-kit expression was observed in only one. No correlations between c-kit positivity and parameters such as cell type, largest macroscopic tumour dimension, scleral invasion or pigmentation were observed. In contrast, a significant positive association was found between c-kit staining and mitotic activity (P = 0.02). However, c-kit expression did not significantly influence survival when evaluated by univariate analysis. In conclusion, c-kit is expressed in most choroidal melanoma tumours. Further analysis should provide new insights into the mechanisms underlying the molecular and cellular changes in choroidal melanomas.

Thermotherapy in the management of choroidal melanoma

During the past 20 years of enucleation, which was the standard treatment for choroidal melanoma over more than a century, has largely been replaced by eye salvaging therapies such as radiotherapy or local resection. In 1995 transpupillary thermotherapy (TTT) using an infrared diode laser was introduced as a new conservative therapy for patients with choroidal melanoma. TTT can be defined as a heat treatment modality, which is delivered through a dilated pupil to the tumour surface. The technique uses a wide diode laser beam diameter with a low irradiance and a long exposure time. TTT induces tumour necrosis at sub-photocoagulation levels by a direct cell destructive effect with only a few ocular complications. TTT can be performed as sole therapy or combined with plaque radiotherapy, thus permitting a lower radiation dose. For amelanotic tumours dye-enhanced TTT with indocyanine green can be used. In this paper we review the role of sole or combined TTT, related to the current other treatment modalities for choroidal melanoma.