Local Recurrence After Primary Proton Beam Therapy in Uveal Melanoma: Risk Factors, Retreatment Approaches, and Outcome

Measurements regarding a combined therapy concept for ophthalmic tumors consisting of brachytherapy and x-rays

Objective.We present a novel concept to treat ophthalmic tumors which combines brachytherapy and low-energy x-ray therapy. Brachytherapy with106Ru applicators is inadequate for intraocular tumors with a height of 7 mm or more. This results from a steep dose gradient, and it is unfeasible to deliver the required dose at the tumor apex without exceeding the maximum tolerable sclera dose of usually 1000 Gy to 1500 Gy. Other modalities, such as irradiation with charged particles, may be individually contraindicated. A dose boost at the apex provided by a superficial x-ray therapy unit, performed simultaneously with the brachytherapy, results in a more homogeneous dose profile than brachytherapy alone. This avoids damage to organs at risk. The applicator may also serve as a beam stop for x-rays passing through the target volume, which reduces healthy tissue dosage. This study aims to investigate the suitability of the applicator to serve as a beam stop for the x-rays.Approach.A phantom with three detector types comprising a soft x-ray ionization chamber, radiochromic films, and a self-made scintillation detector was constructed to perform dosimetry. Measurements were performed using a conventional x-ray unit for superficial therapy to investigate the uncertainties of the phantom and the ability of the applicator to absorb x-rays. The manufacturer provided a dummy plaque to obtain x-ray dose profiles without noise from106Ru decays.Results.The phantom is generally feasible to obtain dose profiles with three different detector types. The interaction of x-rays with the silver of the applicator leads to an increased dose rate in front of the applicator. The dose rate of the x-rays is reduced by up to 90% behind a106Ru applicator. Therefore, a106Ru applicator can be used as a beam stop in combined x-ray and brachytherapy treatment.

External Beam Radiotherapy in the Management of Uveal Melanoma

OPINION STATEMENT

Uveal melanoma is the most common primary ocular tumor in adults. With the evidence demonstrating that episcleral plaque brachytherapy (EPB) has similar survival rates as enucleation in the Collaborative Ocular Melanoma Study (COMS), eye-sparing treatments have come to the fore today. External radiotherapy techniques (proton beam radiotherapy and stereotactic radiosurgery/fractionated stereotactic radiosurgery) are an important treatment option for globe-sparing treatments. There are no prospective randomized trials comparing these techniques; however, retrospective series, meta-analyses, and reviews indicate that these EPB and external radiotherapy techniques are equal. With this review, we aimed to examine the external radiotherapy techniques used in the treatment of uveal melanoma in detail with reference to the current literature.

Re-treatment of locally recurrent uveal melanoma with repeat eye plaque I-125 brachytherapy: A single institution experience

PURPOSE

Eye plaque brachytherapy (EPBT) is the most common treatment for uveal melanoma with high local control rates of 95-100%. When local recurrences occur following EPBT, salvage options include enucleation, transpupillary thermotherapy (TTT), external beam radiation, or re-irradiation with EPBT. The purpose of this study is to report our institution's experience with EPBT re-irradiation for locally recurrent uveal melanoma.

METHODS AND MATERIALS

Patients were included if they were previously treated for uveal melanoma with EPBT, experienced local recurrence, and were subsequently treated at our institution with EPBT from 2016- 2020.

RESULTS

A total of 5 patients with median age 68 years were included. All patients were initially treated at an outside institution (OSI) with Iodine-125 or Ruthenium-106 EPBT. Mean time between EPBT at the OSI and EPBT at our facility was 130 months (range 28-231 months). Patients were re-irradiated with Iodine-125 EPBT prescribed to 85 Gy over 168 hours. Median follow up after re-treatment at our center was 24 months. Local control among this cohort was 100%. Metastasis occurred in two patients after re-treatment, at 8 months and 7 months. At last follow up, all treated lesions were decreased in size. Four patients experienced worsening visual acuity. Four patients developed cataracts, while two patients developed radiation retinopathy with cystoid macular edema requiring anti-VEGF injections. One patient developed radiation retinopathy but did not require injections. No patients required enucleation.

CONCLUSIONS

Re-treatment of locally recurrent uveal melanomas with EPBT is a feasible alternative to enucleation with a high local control rate. Ocular toxicities have not been significant enough to require enucleation.

Survival of patients with recurrent uveal melanoma after treatment with radiation therapy

BACKGROUND/AIMS

We evaluated a large cohort of patients treated for local recurrence of choroidal or ciliary body melanomas at the Massachusetts Eye and Ear (MEE) to quantify the risk of melanoma-related mortality associated with recurrence, independent of other risk factors.

METHODS

Patients treated with radiation therapy from 1982 to 2017 were identified through the Uveal Melanoma Registry at MEE. Competing risks regression was performed to investigate the risk of melanoma-related mortality associated with recurrence, treating recurrence as a time-varying covariate.

RESULTS

Of 4196 patients treated, 4043 patients remained recurrence-free and 153 patients experienced a recurrence (median follow-up: 9.9 years). Median time from initial treatment to recurrence was 30.5 months (range: 2.0-238.7). Seventy-nine (69.9%) patients with recurrences and 826 (37.9%) patients in the recurrence-free group died of metastatic uveal melanoma (p<0.001). Median time from initial treatment to melanoma-related death was 4.9 years (1.0-31.8) for patients who developed recurrences and 4.3 years (0.59-33.8) for patients who did not (p=0.17). Five-year and 10-year probabilities of melanoma-related mortality were 9.5% and 15.0%, respectively, in patients without local recurrences compared with 32.0% and 46.6% in patients with recurrences (p<0.001).

CONCLUSION

These data confirm previous reports that local recurrence is associated with an increased risk of dying of melanoma and quantify the risk that can be attributed to local recurrence independent of other risk factors. This group of patients should be strongly considered for adjuvant therapies when available.

Uncertainties in ocular proton planning and their impact on required margins

PURPOSE

To review required margins in ocular proton therapy (OPT) based on an uncertainty estimation and to compare them with widely used values. Further, uncertainties when using registered funduscopy images in the 3D model is investigated.

METHODS

An uncertainty budget in planning and delivery was defined to determine required aperture and range margins. Setup uncertainties were considered for a cohort of treated patients and tested in a worst-case estimation. Other uncertainties were based on a best-guess and knowledge of institutional specifics, e.g. range reproducibility. Margins for funduscopy registration were defined resulting from scaling, rotation and translation of the image. Image formation for a wide-field fundus camera was reviewed and compared to the projection employed in treatment planning systems.

RESULTS

Values for aperture and range with margins of 2.5 mm as reported in literature could be determined. Aperture margins appear appropriate for setup uncertainties below 0.5 mm, but depend on lateral penumbra. Range margins depend on depth and associated density uncertainty in tissue. Registration of funduscopy images may require margins of >2 mm, increasing towards the equator. Difference in the projection may lead to discrepancies of several mm.

CONCLUSIONS

The commonly used 2.5 mm aperture margin was validated as an appropriate choice, while range margins could be reduced for lower ranges. Margins may however not include uncertainties in contouring and possible microscopic spread. If a target base is contoured on registered funduscopy images care must be taken as they are subject to larger uncertainties. Multimodal imaging approach in OPT remains advisable.

Comparing efficacy of charged-particle therapy with brachytherapy in treatment of uveal melanoma

BACKGROUND

Uveal melanoma (UM) is the most common primary ocular tumour in adults. The most used eye-preserving treatments are charged-particle therapy (CPT) and brachytherapy. We performed a systematic review and meta-analysis to compare efficacies and complications of these two radiotherapies.

METHODS

We searched EMBASE, PubMed, MEDLINE, and the Cochrane Library from January 2012 to December 2022. Two independent reviewers identified controlled studies comparing outcomes of CPT versus brachytherapy. Case series that utilize either treatment modality were also reviewed.

RESULTS

One hundred fifty studies met the eligibility criteria, including 2 randomized control trials, 5 controlled cohort studies, and 143 case series studies. We found significant reduction in local recurrence rate among patients treated with CPT compared to brachytherapy (Odds ratio[OR] 0.38, 95% Confidence interval [CI] 0.24-0.60, p < 0.01). Analysis also showed a trend of increased risks of secondary glaucoma after CPT. No statistically significant differences were found in analyzing risks of mortality, enucleation, and cataract.

CONCLUSIONS

Our study suggested no difference in mortality, enucleation rate and cataract formation rate comparing the two treatments. Lower local recurrence rate and possibly higher secondary glaucoma incidence was noted among patients treated with CPT. Nevertheless, the overall level of evidence is limited, and further high-quality studies are necessary to provide a more definitive conclusion.

Correction Method for Optical Scaling of Fundoscopy Images: Development, Validation, and First Implementation

Purpose

Although fundus photography is extensively used in ophthalmology, refraction prevents accurate distance measurement on fundus images, as the resulting scaling differs between subjects due to varying ocular anatomy. We propose a PARaxial Optical fundus Scaling (PAROS) method to correct for this variation using commonly available clinical data.

Methods

The complete optics of the eye and fundus camera were modeled using ray transfer matrix formalism to obtain fundus image magnification. The subject's ocular geometry was personalized using biometry, spherical equivalent of refraction (RSE), keratometry, and/or corneal topography data. The PAROS method was validated using 41 different eye phantoms and subsequently evaluated in 44 healthy phakic subjects (of whom 11 had phakic intraocular lenses [pIOLs]), 29 pseudophakic subjects, and 21 patients with uveal melanoma.

Results

Validation of the PAROS method showed small differences between model and actual image magnification (maximum 3.3%). Relative to the average eye, large differences in fundus magnification were observed, ranging from 0.79 to 1.48. Magnification was strongly inversely related to RSE (R2 = 0.67). In phakic subjects, magnification was directly proportional to axial length (R2 = 0.34). The inverse relation was seen in pIOL (R2 = 0.79) and pseudophakic (R2 = 0.12) subjects. RSE was a strong contributor to magnification differences (1%-83%). As this effect is not considered in the commonly used Bennett-Littmann method, statistically significant differences up to 40% (mean absolute 9%) were observed compared to the PAROS method (P < 0.001).

Conclusions

The significant differences in fundus image scaling observed among subjects can be accurately accounted for with the PAROS method, enabling more accurate quantitative assessment of fundus photography.

Tebentafusp as a Promising Drug for the Treatment of Uveal Melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults and commonly occurs in the Caucasian population. The malignancy involves the uvea of the eye, which includes the iris, ciliary body, and choroid. The etiology of UM is still not well understood, but age is a risk factor. Symptoms include blurred vision, redness of the eye, floaters, dark spots, a change in the size of the pupil, and loss of vision. The location, shape, and size of the tumor are important for therapeutic purposes. Treating metastasis is always a challenge in UM cases. In cases of lung metastasis, the survival rate decreases. Treatment includes surgery, laser therapy, immunotherapy, hormone therapy, and chemotherapy. Recently, in 2022, the United States Food and Drug Administration (FDA) approved the drug tebentafusp. Tebentafusp was developed to target the most common HLA complex in humans. The present review discusses the indications for the use of a new drug tebentafusp, its mechanism of action, dose, pharmacokinetics, results of clinical trials conducted, and adverse effects like cytokine release syndrome. Hence, tebentafusp is the first T cell receptor (TCR) therapeutic drug that could be considered for the treatment of UM.

Treatment with Anti-HER2 Chimeric Antigen Receptor Tumor-Infiltrating Lymphocytes (CAR-TILs) Is Safe and Associated with Antitumor Efficacy in Mice and Companion Dogs

Patients with metastatic melanoma have a historically poor prognosis, but recent advances in treatment options, including targeted therapy and immunotherapy, have drastically improved the outcomes for some of these patients. However, not all patients respond to available treatments, and around 50% of patients with metastatic cutaneous melanoma and almost all patients with metastases of uveal melanoma die of their disease. Thus, there is a need for novel treatment strategies for patients with melanoma that do not benefit from the available therapies. Chimeric antigen receptor-expressing T (CAR-T) cells are largely unexplored in melanoma. Traditionally, CAR-T cells have been produced by transducing blood-derived T cells with a virus expressing CAR. However, tumor-infiltrating lymphocytes (TILs) can also be engineered to express CAR, and such CAR-TILs could be dual-targeting. To this end, tumor samples and autologous TILs from metastasized human uveal and cutaneous melanoma were expanded in vitro and transduced with a lentiviral vector encoding an anti-HER2 CAR construct. When infused into patient-derived xenograft (PDX) mouse models carrying autologous tumors, CAR-TILs were able to eradicate melanoma, even in the absence of antigen presentation by HLA. To advance this concept to the clinic and assess its safety in an immune-competent and human-patient-like setting, we treated four companion dogs with autologous anti-HER2 CAR-TILs. We found that these cells were tolerable and showed signs of anti-tumor activity. Taken together, CAR-TIL therapy is a promising avenue for broadening the tumor-targeting capacity of TILs in patients with checkpoint immunotherapy-resistant melanoma.

Choroidal Melanoma: A Mini Review

Choroidal melanoma is a rare malignant tumour, yet it is the most common primary intra-ocular neoplasm and second on the list of top ten most malignant melanoma sites in the body. Clinical presentation can be non-specific and includes photopsia, floaters, progressive visual field loss, and blurry vision. The tumour is quite often diagnosed clinically during fundus examination; however, the most valued diagnostic tests are A- and B-scan ultrasonography (US). Several factors affect prognosis, including the patient's age, tumour size, histological features, and presence of metastases. Still, with primary treatment and tight surveillance, around 50% of choroidal melanoma patients metastasise.

Inter-Observer Variability in MR-Based Target Volume Delineation of Uveal Melanoma

Purpose

Several efforts are being undertaken toward MRI-based treatment planning for ocular proton therapy for uveal melanoma (UM). The interobserver variability of the gross target volume (GTV) on magnetic resonance imaging (MRI) is one of the important parameters to design safety margins for a reliable treatment. Therefore, this study assessed the interobserver variation in GTV delineation of UM on MRI.

Methods and Materials

Six observers delineated the GTV in 10 different patients using the Big Brother contouring software. Patients were scanned at 3T MRI with a surface coil, and tumors were delineated separately on contrast enhanced 3DT1 (T1gd) and 3DT2-weighted scans with an isotropic acquisition resolution of 0.8 mm. Volume difference and overall local variation (median standard deviation of the distance between the delineated contours and the median contour) were analyzed for each GTV. Additionally, the local variation was analyzed for 4 interfaces: sclera, vitreous, retinal detachment, and tumor-choroid interface.

Results

The average GTV was significantly larger on T1gd (0.57cm³) compared with T2 (0.51cm³, P = .01). A not significant higher interobserver variation was found on T1gd (0.41 mm) compared with T2 (0.35 mm). The largest variations were found at the tumor-choroid interface due to peritumoral enhancement (T1gd, 0.62 mm; T2, 0.52 mm). As a result, a larger part of this tumor-choroid interface appeared to be included on T1gd-based GTVs compared with T2, explaining the smaller volumes on T2.

Conclusions

The interobserver variation of 0.4 mm on MRI are low with respect to the voxel size of 0.8 mm, enabling small treatment margins. We recommend delineation based on the T1gd-weighted scans, as choroidal tumor extensions might be missed.

Recent Advances and Challenges in Uveal Melanoma Immunotherapy

Simple Summary

Uveal melanoma is the most common primary intraocular malignancy in adults. Although it can be controlled locally, half of the patients still develop metastases. To date, there have been no standard therapeutic strategies for the prevention or treatment of metastases. Existing therapies, such as chemotherapy and targeted therapies, induce only minimal responses. This review focuses on newly published research on immunotherapy. We highlight expanding treatments and their clinical outcomes, as well as propose promising new treatments and feasible checkpoints. Based on these findings, we provide innovative insights into feasible strategies for the treatment of patients with uveal melanoma.

Abstract

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Compared to cutaneous melanoma (CM), which mainly harbors BRAF or NRAS mutations, UM predominantly harbors GNAQ or GNA11 mutations. Although primary UM can be controlled locally, approximately 50% of patients still develop metastases. To date, there have been no standard therapeutic strategies for the prevention or treatment of metastases. Unfortunately, chemotherapy and targeted therapies only induce minimal responses in patients with metastatic UM, with a median survival time of only 4–5 months after metastasis detection. Immunotherapy agents, such as immune checkpoint inhibitors, have achieved pioneering outcomes in CM but have shown limited effects in UM. Researchers have explored several feasible checkpoints to identify options for future therapies. Cancer vaccines have shown little in the way of therapeutic benefit in patients with UM, and there are few ongoing trials providing favorable evidence, but adoptive cell transfer-related therapies seem promising and deserve further investigation. More recently, the immune-mobilizing monoclonal T-cell receptor against the cancer molecule tebentafusp showed impressive antitumor effects. Meanwhile, oncolytic viruses and small molecule inhibitors have also gained ground. This review highlights recent progress in burgeoning treatments and provides innovative insights on feasible strategies for the treatment of UM.

Sclerostin Suppression Facilitates Uveal Melanoma Progression Through Activating Wnt/β-Catenin Signaling Via Binding to Membrane Receptors LRP5/LRP6

Objective

Uveal melanoma (UM) is the most frequent primary eye cancer in adults with a 50% mortality rate. Characterizing the fundamental signaling pathways that drive UM is of importance for the development of targeted therapy. This study aims to probe the impact of sclerostin (SOST) on malignant progression of UM and regulation of Wnt/β-catenin signaling.

Methods

Epithelial-type (n=20) and spindle-type (n=16) UM tissues were collected for immunohistochemical staining of SOST, Wnt-1, and β-catenin expressions. SOST was silenced in three UM cell lines (primary spindle-type OCM-1 cells, metastatic epithelial Mum-2B cells, and metastatic spindle-type Mum-2C cells) through transfecting specific siRNA. RT-qPCR and Western blot were presented for examining the levels of SOST, and markers in Wnt/β-catenin signaling. Flow cytometry, MTT, EdU, transwell, and tube formation assays were conducted, respectively. By implanting BALB/c nude murine models in situ, the function of SOST on tumor growth was investigated, followed by immunofluorescence double staining of SOST and LRP5/6.

Results

Low SOST expression as well as high Wnt-1 and β-catenin expressions were found in epithelial-type (high malignancy) than spindle-type (low malignancy) UM tissues. Silencing SOST activated the markers in Wnt/β-catenin signaling as well as accelerated cell cycle progression, migration, invasion, angiogenesis, and reduced apoptosis in UM cells. In situ tumor formation in murine eyes showed that SOST knockdown promoted tumor growth. Moreover, SOST interacted with LRP5/LRP6.

Conclusion

SOST silencing may facilitate the malignant progression of UM cells through activating Wnt/β-catenin signaling. Mechanistically, SOST may exert this function by interacting with LRP5/LRP6 membrane receptors.

Technical Note: Impact of Beam Properties for Uveal Melanoma Proton Therapy - An In-Silico Planning Study

PURPOSE

To evaluate the impact of beam quality in terms of distal fall-off (DFO, 90% to 10%) and lateral penumbra (LP, 80% to 20%) of single beam ocular proton treatment (OPT) and to derive resulting ideal requirements for future systems.

METHODS

Nine different beam models with DFO varying between 1 mm and 4 mm and LP between 1 mm and 4 mm were created. Beam models were incorporated into the RayStation with RayOcular TPS version 10 B (RaySearch Laboratories, Sweden). Each beam model was applied for eight typical clinical cases, covering different sizes and locations of uveal melanoma. Plans with and without an additional wedge were created, resulting in 117 plans with a total prescribed median dose of 60 Gy(RBE) to the CTV. Treatment plans were analyzed in terms of V20-V80 penumbra volume, D1 (dose to 1% of the volume) for optic disc and macula, optic nerve V30 (volume receiving 30 Gy(RBE), i.e. 50% of prescription), as well as average dose to lens and ciliary body. A LP dependent aperture margin was based on estimated uncertainties, ranging from 1.7 mm to 4.0 mm.

RESULTS

V20-V80 showed a strong influence by LP, while DFO was less relevant. The optic disc D1 reached an extra dose of up to 3000 cGy(RBE), comparing the defined technical limit of DFO = LP = 1 mm with DFO = 3 mm/ LP = 4 mm. The latter may result from a pencil-beam scanning (PBS) system with static apertures. Plans employing a wedge showed an improvement for organs at risk (OAR) sparing.

CONCLUSION

Plan quality is strongly influenced by initial beam parameters. The impact of LP is more pronounced when compared to DFO. The latter becomes important in the treatment of posterior tumors near the macula, optic disc or optic nerve. The plan quality achieved by dedicated OPT nozzles in single- or double-scattering design might not be achievable with modified PBS systems. This article is protected by copyright. All rights reserved.

Long-Term Outcomes in Uveal Melanoma After Ruthenium-106 Brachytherapy

Uveal melanoma is the most common primary intraocular malignancy. The aim of this retrospective study was to report the results after ruthenium-106 (Ru-106) plaque brachytherapy for uveal melanoma in terms of tumor control, visual acuity, radiation-related complications, tumor recurrence, metastases, and patients’ survival rate during 4 years’ follow-up. A total of 355 eyes from 355 patients have been treated with Ru-106 plaque brachytherapy for uveal melanoma between February 2011 and March 2020. Five patients were lost to follow-up, and then 350 eyes of 350 patients (mean age 58 ± 11 years) were enrolled in this retrospective study. All patients underwent a complete ophthalmic examination including echography and spectral domain–optical coherence tomography. The mean follow-up was 4 years (3 months to 9 years). After treatment, the mean tumor thickness was reduced to 1.75 ± 0.21 mm. Radiation complications were found in 63% of patients: 38% showed radiation maculopathy, 11% had optic neuropathy, and 14% developed cataracts. Cancer-free survival was 99%, 97%, and 85%, respectively, at 5, 7, and 9 years. Ru-106 plaque brachytherapy represents a reliable treatment of uveal melanoma. This technique is valid and safe with a low rate of ocular complications during a long-term follow-up.

Clinical Outcomes after International Referral of Uveal Melanoma Patients for Proton Therapy

Simple Summary

This study aims to assess cancer control and preservation of the eye and visual acuity after proton therapy abroad for eye melanoma. For this, medical files were reviewed of Dutch uveal melanoma patients who were treated in Switzerland with proton therapy from 1987 to 2019. The tumours of these patients were too large and/or localised too close to the optic nerve to be treated with local plaque irradiation. There were 103 patients, of whom one had a uveal melanoma in both eyes. The tumours were relatively large and often localised around the central part of the retina. At five years after treatment, proton therapy had controlled the uveal melanomas of 94% of the patients and 81% had preserved their eye. Spread of the cancer beyond the eye was observed in 30% of the patients. Most patients (79%) became blind or had severe visual impairment after proton therapy; a small group of patients had mild or no visual impairment (17%). The size of the tumour, its localisation and the dose of proton therapy were important for the risk of decline in visual acuity. This study shows that proton therapy abroad for uveal melanoma is feasible and yields good results.

Abstract

Objective: To assess oncological and ophthalmological outcomes after international referral of uveal melanoma patients for proton therapy. Materials and Methods: This is a retrospective study among Dutch uveal melanoma patients who were treated in Switzerland with 60.0 CGE proton therapy (in 4 fractions) from 1987 to 2019. All patients were ineligible for brachytherapy due to tumour size and/or proximity to the optic nerve. Time-to-event analyses were performed using Kaplan–Meier’s methodology and Cox proportional hazards models. Results: There were 103 patients (104 eyes) with a median largest tumour diameter of 19 mm (range 6–26 mm). Tumours were localised centrally (11%), mid-peripherally (65%) or peripherally (34%). Median follow-up was 7 years. Five-year local control, distant metastasis-free survival and eye preservation rates were 94%, 70% and 81% respectively. At five years, severe, moderate and mild visual impairment was observed in respectively 79%, 4% and 6% of the patients. Larger tumour volumes and more central tumour localisation were associated with severe visual impairment. After correction for these factors, dose to the macula, optic disc and retina, but not optic nerve was significantly associated with severe visual impairment. Conclusion: International referral for proton therapy yielded good tumour control and eye preservation rates, but risk of distant metastasis and severe visual impairment were substantial, possibly due to the selection of advanced tumour stages and/or central localisation. Dose to the macula may be more relevant than dose to the optic nerve for preservation of visual acuity, which is relevant for the treatment planning of proton therapy.

Large Hemorrhagic Extrascleral Ciliary Body Melanoma Recurrence Treated With Transarterial Embolization and Coiling Followed by Exenteration

A 59-year-old male patient who suffered from a systemically metastasized, large extrascleral uveal melanoma recurrence of the left eye presented with active hemorrhage from the tumor. He had undergone proton beam irradiation for an epithelioid ciliary body melanoma 4 years before presentation and was lost to follow-up. Magnetic resonance angiography showed vascularization of the lesion via the ophthalmic and maxillary artery. Selective transarterial embolization of the tumor was conducted with polyvinyl alcohol microparticles followed by coiling of the supplying arteries. The bleeding stopped after 2 days and the tumor started to become necrotic. As tumor removal was the primary wish of the patient at this point in time, exenteration was carried out a week later without significant blood loss, intraoperative or postoperative complications. Socket healing was adequate, and the patient reported improved quality of life. He refused systemic palliative treatment and died 3 months after the intervention.

Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging-Part II: treatment indications and complications

Therapy of uveal melanoma aims to preserve the eye and its function and to avoid metastatic dissemination. The treatment choice is difficult and must keep into account several factors; the therapeutic strategy of uveal melanoma should therefore be personalized, sometimes requiring to combine different treatment techniques. Nowadays globe-sparing radiotherapy techniques are often preferred to enucleation. Plaque brachytherapy, the most commonly used eye-preserving therapy, is suitable for small- and medium-sized uveal melanomas. Proton beam radiotherapy is indicated for tumours with noticeable size, challenging shape and location, but is more expensive and less available than brachytherapy. Enucleation is currently restricted to advanced tumours, uveal melanomas with orbital or optic nerve involvement, blind and painful eyes because of treatment-related complications (neovascular glaucoma, chronic inflammatory processes). The effect of proton beam therapy on neoplastic tissue is related to direct cytotoxic action of the radiations, impairment of neoplastic vascular supply and immunologic response. Complications after radiotherapy are frequent and numerous and mainly related to tumour thickness, radiation dose and distance between the tumour and optic nerve. The purpose of this pictorial review is to provide the radiologists with awareness about diagnostic methods and therapeutic options of uveal melanoma. In the present second section, we discuss the therapeutic management of uveal melanoma, describing the main ocular-conserving radiotherapic techniques. We subsequently present an overview of the effects of radiations on neoplastic tissue. Lastly, we review ocular complications following radiotherapy that should be evaluated by radiologists during follow-up MRI examinations.

Recent advancements in the management of retinoblastoma and uveal melanoma

Retinoblastoma in children and uveal melanoma in adults can pose a serious threat to both vision and life. For many decades, enucleation was often the only option to treat these intraocular malignancies. For retinoblastoma, intra-arterial chemotherapy is often utilized as the primary treatment at advanced academic centers and has dramatically improved local tumor control and eye salvage rates. For uveal melanoma, both plaque brachytherapy and proton beam irradiation have served as widely utilized therapies with a local failure rate of approximately 1–10%, depending on the series. Major recent advancements have allowed for a better understanding of the genomics of uveal melanoma and the impact of certain mutations on metastatic susceptibility. Gene expression profile stratifies uveal melanomas into two classes: low-risk (class 1) and high-risk (class 2). A loss-of-function mutation of BAP1 is associated with a class 2 gene expression profile and therefore confers worse prognosis due to elevated risk of metastasis. On the other hand, gain-of-function mutations of EIF1AX and SF3B1 correspond to a gene expression profile of class 1A and class 1B and confer a better prognosis. Preferentially expressed antigen in melanoma (PRAME) is an antigen that increases metastatic susceptibility when expressed in uveal melanoma cells. In addition to plaque brachytherapy and proton beam irradiation, both of which have demonstrated superb clinical outcomes, scientists are actively investigating newer therapeutic modalities as either primary therapy or adjuvant treatment, including a novel nanoparticle therapy and immunotherapy.

Hypoxia-dependent drivers of melanoma progression

Hypoxia, a condition of low oxygen availability, is a hallmark of tumour microenvironment and promotes cancer progression and resistance to therapy. Many studies reported the essential role of hypoxia in regulating invasiveness, angiogenesis, vasculogenic mimicry and response to therapy in melanoma. Melanoma is an aggressive cancer originating from melanocytes located in the skin (cutaneous melanoma), in the uveal tract of the eye (uveal melanoma) or in mucosal membranes (mucosal melanoma). These three subtypes of melanoma represent distinct neoplasms in terms of biology, epidemiology, aetiology, molecular profile and clinical features.In this review, the latest progress in hypoxia-regulated pathways involved in the development and progression of all melanoma subtypes were discussed. We also summarized current knowledge on preclinical studies with drugs targeting Hypoxia-Inducible Factor-1, angiogenesis or vasculogenic mimicry. Finally, we described available evidence on clinical studies investigating the use of Hypoxia-Inducible Factor-1 inhibitors or antiangiogenic drugs, alone or in combination with other strategies, in metastatic and adjuvant settings of cutaneous, uveal and mucosal melanoma.Hypoxia-Inducible Factor-independent pathways have been also reported to regulate melanoma progression, but this issue is beyond the scope of this review.As evident from the numerous studies discussed in this review, the increasing knowledge of hypoxia-regulated pathways in melanoma progression and the promising results obtained from novel antiangiogenic therapies, could offer new perspectives in clinical practice in order to improve survival outcomes of melanoma patients.

Iatrogenic Ocular Surface Diseases Occurring during and/or after Different Treatments for Ocular Tumours

Simple Summary

The ocular surface represents a finely regulated system that allows the protection of the eye. It can be affected by therapies used for the treatment of various intraocular tumours, particularly conjunctival cancers and uveal melanoma. In these conditions, treatments are chosen according to the characteristics of the lesion, and include a combination of selective surgery, anticancer eye drops, and/or radiotherapy delivered through different mechanisms. Possible side effects affecting the ocular surface range from transient dry eye or keratitis up to more severe complications such as corneal melting and perforation. These complications deserve careful evaluation for the risk of permanent sight-threatening sequelae. Physicians involved in the management of patients affected by ocular tumours should be aware of this risk in order to reach an early diagnosis and promptly set up an adequate treatment. The present review summarizes acute and chronic complications affecting the ocular surface following different therapies for the treatment of conjunctival cancers and uveal melanoma, and also reports clinical cases of representative patients who experienced these complications.

Abstract

The ocular surface represents a finely regulated system that allows the protection of the eye. It is particularly susceptible to different treatments for intraocular tumours, such as uveal melanoma and conjunctival cancers. Traditionally, the management of ocular tumours depends on the characteristics of the lesion, and is based on a combination of selective surgery, topical chemotherapy, and/or radiotherapy delivered through different mechanisms (e.g., charged-particle radiotherapy or brachytherapy). Possible complications involving the ocular surface range from transient dry eye disease or keratitis up to corneal melting and perforation, which in any case deserve careful evaluation for the risk of permanent sigh-threatening complications. Clinicians involved in the management of these patients must be aware of this risk, in order to reach an early diagnosis and promptly set up an adequate treatment. The present review of the literature will summarize acute and chronic complications affecting the ocular surface following different therapies for the treatment of ocular tumours.

Three-dimensional MRI-based treatment planning approach for non-invasive ocular proton therapy

PURPOSE

To develop a high-resolution three-dimensional (3D) magnetic resonance imaging (MRI)-based treatment planning approach for uveal melanomas (UM) in proton therapy.

MATERIALS/METHODS

For eight patients with UM, a segmentation of the gross tumor volume (GTV) and organs-at-risk (OARs) was performed on T1- and T2-weighted 7 Tesla MRI image data to reconstruct the patient MR-eye. An extended contour was defined with a 2.5-mm isotropic margin derived from the GTV. A broad beam algorithm, which we have called πDose, was implemented to calculate relative proton absorbed doses to the ipsilateral OARs. Clinically favorable gazing angles of the treated eye were assessed by calculating a global weighted-sum objective function, which set penalties for OARs and extreme gazing angles. An optimizer, which we have named OPT'im-Eye-Tool, was developed to tune the parameters of the functions for sparing critical-OARs.

RESULTS

In total, 441 gazing angles were simulated for every patient. Target coverage including margins was achieved in all the cases (V95%  > 95%). Over the whole gazing angles solutions space, maximum dose (Dmax ) to the optic nerve and the macula, and mean doses (Dmean ) to the lens, the ciliary body and the sclera were calculated. A forward optimization was applied by OPT'im-Eye-Tool in three different prioritizations: iso-weighted, optic nerve prioritized, and macula prioritized. In each, the function values were depicted in a selection tool to select the optimal gazing angle(s). For example, patient 4 had a T2 equatorial tumor. The optimization applied for the straight gazing angle resulted in objective function values of 0.46 (iso-weighted situation), 0.90 (optic nerve prioritization) and 0.08 (macula prioritization) demonstrating the impact of that angle in different clinical approaches.

CONCLUSIONS

The feasibility and suitability of a 3D MRI-based treatment planning approach have been successfully tested on a cohort of eight patients diagnosed with UM. Moreover, a gaze-angle trade-off dose optimization with respect to OARs sparing has been developed. Further validation of the whole treatment process is the next step in the goal to achieve both a non-invasive and a personalized proton therapy treatment.

FLASH proton irradiation setup with a modulator wheel for a single mouse eye

PURPOSE

Recent studies indicate that FLASH irradiation, which involves ultra-high dose rates in a short time window (usually >40 Gy/s in <500 ms), might be equally efficient against tumors but less harmful to healthy tissues, compared to conventional irradiation with the same total dose. Aiming to verify the latter claim for ocular proton radiotherapy, in vivo experiments with mice are being carried out by Charité - Universitätsmedizin Berlin. This work presents the implemented setup for delivering FLASH proton radiation to a single eye of mice at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB).

MATERIALS AND METHODS

The HZB cyclotron is tuned to provide a high-intensity 68 MeV focused proton beam. Outside the vacuum beamline, the protons hit a single scatterer, which also serves as range shifter, and a rotating modulator wheel, which produces a flat depth-dose distribution. Two transmission ionization chambers in between, read out by fast electronics, are used as dose monitors for triggering an in-vacuum beam shutter, which blocks the beam once the desired dose has been delivered. A collimating aperture shapes the radiation field at the isocenter, which is measured by a radioluminescent screen and a CCD camera. At the same position, a parallel-plate ionization chamber of type Advanced Markus^® is used for absolute dosimetry and characterization of the spread-out Bragg peak inside a water phantom. A thin-foil mirror of adjustable tilt in the beam path assists the correct alignment of the target through side illumination. Radiochromic films of type EBT3 are used to supplement the dosimetry and assist the alignment.

RESULTS

A dose rate of 75 Gy/s has been measured, delivering within 200 ms 15 Gy (RBE) with a reproducibility better than ±1%. A depth-dose curve with a range of 5.2 mm in water, 0.9 mm distal fall-off (90%-10%), and ±2.5% ripple has been demonstrated, with a PTV of 6.3 mm diameter, 1.7 mm lateral penumbra (90%-10%), 8% uniformity, and 3% symmetry.

CONCLUSIONS

The implemented setup is able to accommodate ocular irradiation of narcotized mice with protons, targeting selectively the left or the right eye, under conventional and FLASH conditions. Switching between these two modes can be done within half an hour, including the calibration of the dose monitors and the verification of the dose delivery. Further upgrades are planned after the completion of the on-going experiment.

Local tumour control and radiation side effects for fractionated stereotactic photon beam radiotherapy compared to proton beam radiotherapy in uveal melanoma

PURPOSE

To compare the adverse side effects of fractionated stereotactic photon beam radiotherapy (fSRT) with proton beam radiotherapy (PBR) in patients with uveal melanoma (UM).

METHODS

A retrospective study investigating 306 UM patients treated with fSRT (N=153) by the Rotterdam Ocular Melanoma Study group (ROMS), The Netherlands, between 1999-2014 or with PBR (N=153) at the Royal Liverpool University Hospital and the Clatterbridge Cancer Centre, Bebington, United Kingdom, between 1993-2014. The tumours treated with fSRT were matched with tumours treated with PBR based on sex, left or right eye, TNM classification, posterior margin ≤ or > 3mm of the fovea and of the optic disc.

RESULTS

The five-year actuarial rates of tumour recurrence were 4.5% for fSRT and 6.1% for PBR. For fSRT and PBR, the five-year actuarial rates of maculopathy were 14.9% and 12.4%, and for vitreous haemorrhage were 29.4% and 4.7%, respectively. Only vitreous haemorrhage (HR: 0.19, 95% CI: 0.07-0.56) was more common after fSRT compared to PBR. Overall, larger tumours were risk factors for maculopathy and secondary enucleation.

CONCLUSIONS

Both treatments have excellent local tumour control. In matched groups, vitreous haemorrhage was the only adverse side effect showing a significant difference between groups.

Hypofractionated stereotactic photon radiotherapy of choroidal melanoma: 20-year experience

BACKGROUND

To evaluate the long-term results after hypofractionated stereotactic photon radiotherapy (SRT) in patients with choroidal melanoma treated between 1997 and 2016.

MATERIAL AND METHODS

A total of 335 patients (183 male and 152 female) with choroidal melanoma unsuitable for ruthenium-106 brachytherapy or local resection were treated with linear accelerator-based SRT at the Medical University of Vienna. All patients received five fractions with either 10, 12 or 14 Gy per fraction. A complete ophthalmic examination including visual acuity and measurement of the tumor base and height using standardized A- and B-scan ultrasonography was performed every 3 months in the first 2 years, every 6 months until 5 years and yearly thereafter. Early and late adverse side effects were assessed at every follow-up visit.

RESULTS

The median overall follow-up was 78.6 months (39.1 to 113.7 months). Local tumor control was 95.4% after 10 and 12 years, respectively. Fifty-four patients developed metastatic disease, and 31 died during the follow-up. Mean visual acuity decreased from 0.55 Snellen at baseline to 0.05 Snellen at the last individual follow-up. Ischemic retinopathy (192/335cases) and optic neuropathy (174/335cases) were the most common radiogenic side effects, followed by radiogenic cataract (n = 127), neovascular glaucoma (n = 71) and corneal epithelium defects (n = 49). Enucleation was performed in 54 patients mostly due to neovascular glaucoma (n = 41) or tumor recurrence (n = 10) during the study period. The eye retention rate was 79.7% after 10 and 12 years.

CONCLUSION

Hypofractionated stereotactic photon radiotherapy showed a high rate of local tumor control for choroidal melanoma and an acceptable rate of radiogenic side effects.

Proton beam irradiation of uveal melanoma involving the iris, ciliary body and anterior choroid without surgical localisation (light field)

AIMS

To assess treatment outcomes after proton beam irradiation (PBI) without surgical localisation of uveal melanomas involving the iris, ciliary body and anterior choroid.

METHODS

Retrospective chart review of 125 patients evaluated at Massachusetts Eye and Ear and treated with PBI using a light field set-up without localisation surgery between November 1975 and April 2017. The tumours were characterised as follows: iris (n=18, 14.4%), ciliary body (n=12, 9.6%), iridociliary (n=58, 46.4%), ciliochoroidal (n=24, 19.2%) and iridociliochoroidal (n=13, 10.4%). The tumours were measured by transillumination and ultrasonography before treatment. Tumours with posterior margin located less than two disc diameters from the ora serrata were treated using the light field technique. Patient outcomes after PBI were evaluated.

RESULTS

Most patients had good vision at the time of tumour diagnosis (69.6% had baseline visual acuity (VA) of ≥20/40). Median VA at last follow-up (median follow-up: 72.1 months) was 20/63. Recurrences occurred in 12 patients (9.6%) at a median time of 4.0 years post-treatment. Recurrences were treated by repeat PBI (n=5) or enucleation (n=7). Secondary enucleation was performed in 18 patients (14.4%), and 61.1% of these were due to complications. Neovascular glaucoma (NVG) developed in 21 patients (16.8%). Of seven patients who developed NVG after anti-vascular endothelial growth factor (anti-VEGF) therapies became available, five were treated with intravitreal Avastin injections (23.8% of patients with NVG). Of 69 patients diagnosed with cataract after treatment, 51 (73.9%) were characterised as radiation-related. Death from metastatic uveal melanoma occurred in 20.8% of the cohort, with a median follow-up of 10.1 years.

CONCLUSIONS

Patients treated with PBI using a light field set-up technique experience good outcomes after irradiation. Eye preservation and retention of good VA are seen in the majority of cases, and tumour recurrence is low.

Artificial intelligence for modeling uveal melanoma

Understanding of the cellular signaling pathways involved in cancer disease is of great importance. These complex biological mechanisms can be thoroughly revealed by their structure, dynamics, and control methods. Artificial intelligence offers rule-based models that favor the research of human signaling processes. In this paper, we give an overview of the advantages of the formalism of symbolic models in medical biology and cell biology of the uveal melanoma. A language is described that allows us: (1) To define the system states and elements with their alterations; (2) To model the dynamics of the cellular system; and (3) To perform inference-based analysis with the logical tools of the language.

Prognostic significance of PD-1/PD-L1 expression in uveal melanoma: correlation with tumor-infiltrating lymphocytes and clinicopathological parameters

BACKGROUND

To understand how to improve the effect of immune checkpoint inhibitors in uveal melanoma (UM), we need a better understanding of the expression of PD-1 and PD-L1, their relation with the presence of tumor-infiltrating lymphocytes (TILs), and their prognostic relevance in UM patients.

MATERIALS AND METHODS

Expression of PD-1 and PD-L1 was assessed in 71 UM tissue samples by immunohistochemistry and quantitative real-time PCR (qRT-PCR), and further validated by western blotting. The effect of interferon gamma (IFN-γ) on PD-1/PD-L1 expression was determined on four UM cell lines.

RESULTS

Immunoreactivity of PD-1 was found in 30/71 cases and of PD-L1 in 44/71 UM samples. Tumor-infiltrating lymphocytes were found in 46% of UM tissues. PD-1 was expressed on TILs while tumor cells expressed PD-L1. UM with and without TILs showed expression of PD-1 in 69% and 18% cases, respectively (p = 0.001). Similarly, PD-L1 was found in 75% of UM with TILs and in 50% of cases without TILs, respectively (p = 0.03). DFS rate were lower in patients with TILs with expression of PD-1 and PD-L1, but the rate of DFS was higher with expression of PD-L1 in patients without TILs. After treatment of UM cell lines with IFN-γ, PD-1 expression was induced in all UM cell lines whereas PD-L1 expression was found at a lower level in untreated cells, while expression also increased following treatment with IFN-γ.

CONCLUSION

Our study suggests that increased infiltration with TILs promotes the aggressive behavior and suppresses the immune response of UM cells, thereby inhibiting immunotherapy.

Molecular Insights and Emerging Strategies for Treatment of Metastatic Uveal Melanoma

Uveal melanoma (UM) is the most common intraocular cancer. In recent decades, major advances have been achieved in the diagnosis and prognosis of UM allowing for tailored treatments. However, nearly 50% of patients still develop metastatic disease with survival rates of less than 1 year. There is currently no standard of adjuvant and metastatic treatment in UM, and available therapies are ineffective resulting from cutaneous melanoma protocols. Advances and novel treatment options including liver-directed therapies, immunotherapy, and targeted-therapy have been investigated in UM-dedicated clinical trials on single compounds or combinational therapies, with promising results. Therapies aimed at prolonging or targeting metastatic tumor dormancy provided encouraging results in other cancers, and need to be explored in UM. In this review, the latest progress in the diagnosis, prognosis, and treatment of UM in adjuvant and metastatic settings are discussed. In addition, novel insights into tumor genetics, biology and immunology, and the mechanisms underlying metastatic dormancy are discussed. As evident from the numerous studies discussed in this review, the increasing knowledge of this disease and the promising results from testing of novel individualized therapies could offer future perspectives for translating in clinical use.

The Role of Immune Checkpoint Blockade in Uveal Melanoma

Uveal melanoma (UM) represents the most common intraocular malignancy in adults and accounts for about 5% of all melanomas. Primary disease can be effectively controlled by several local therapy options, but UM has a high potential for metastatic spread, especially to the liver. Despite its clinical and genetic heterogeneity, therapy of metastatic UM has largely been adopted from cutaneous melanoma (CM) with discouraging results until now. The introduction of antibodies targeting CTLA-4 and PD-1 for immune checkpoint blockade (ICB) has revolutionized the field of cancer therapy and has achieved pioneering results in metastatic CM. Thus, expectations were high that patients with metastatic UM would also benefit from these new therapy options. This review provides a comprehensive and up-to-date overview on the role of ICB in UM. We give a summary of UM biology, its clinical features, and how it differs from CM. The results of several studies that have been investigating ICB in metastatic UM are presented. We discuss possible reasons for the lack of efficacy of ICB in UM compared to CM, highlight the pitfalls of ICB in this cancer entity, and explain why other immune-modulating therapies could still be an option for future UM therapies.

Breakdown of the blood-eye barrier in choroidal melanoma after proton beam radiotherapy

PURPOSE

Irradiation of choroidal melanoma is a safe and globe preserving procedure. Chronic inflammatory processes and ischemia are the main reasons for secondary enucleation in the long run. The aim of this study was to determine whether intraocular inflammation and especially inflammatory response after proton beam therapy (PBT) is related to primary tumor characteristics such as height, tumor volume, and initial flare values.

METHODS

Twenty-six patients treated for uveal melanoma using PBT were included. All patients were examined for signs of inflammation using laser flare photometry (LFP). Each examination included assessment of the melanoma and fellow eye (which acted as the control) and imaging of the melanoma.

RESULTS

Significant differences of flare values between melanoma eyes and control group were found both at baseline (median 17.65 ph/ms (min 4, max 37.10), 7.45 ph/ms (min 0.80, max 16.40), respectively) and during follow-up (median 21.45 ph/ms (min 4.5, max 70.90); 6.05 ph/ms (min 2.40, max 16.40), respectively) (p < 0.001, Wilcoxon test). Flare values in melanoma eyes increased significantly after PBT (p = 0.005, Wilcoxon test) and after a follow-up of 94 days (median, 7-420 days). Flare values of the control group did not change (p = 0.946, Wilcoxon test). The increase of flare values correlated significantly with maximum tumor height and volume (Spearman-Rho 0.633, p = 0.001 and 0.519, p = 0.007, respectively).

CONCLUSION

LFP has proven to show significantly higher flare values in melanoma eyes as compared with the control group and provides data on the course of the inflammatory response after treatment. It may ease treatment planning both at baseline and during follow-up.

Radiotherapy for Melanoma: More than DNA Damage

Despite its reputation as a radioresistant tumour, there is evidence to support a role for radiotherapy in patients with melanoma and we summarise current clinical practice. Melanoma is a highly immunogenic tumour and in this era of immunotherapy, there is renewed interest in the potential of irradiation, not only as an adjuvant and palliative treatment, but also as an immune stimulant. It has long been known that radiation causes not only DNA strand breaks, apoptosis, and necrosis, but also immunogenic modulation and cell death through the induction of dendritic cells, cell adhesion molecules, death receptors, and tumour-associated antigens, effectively transforming the tumour into an individualised vaccine. This immune response can be enhanced by the application of clinical hyperthermia as evidenced by randomised trial data in patients with melanoma. The large fraction sizes used in cranial radiosurgery and stereotactic body radiotherapy are more immunogenic than conventional fractionation, which provides additional radiobiological justification for these techniques in this disease entity. Given the immune priming effect of radiotherapy, there is a strong but complex biological rationale and an increasing body of evidence for synergy in combination with immune checkpoint inhibitors, which are now first-line therapy in patients with recurrent or metastatic melanoma. There is great potential to increase local control and abscopal effects by combining radiotherapy with both immunotherapy and hyperthermia, and a combination of all three modalities is suggested as the next important trial in this refractory disease.

Personalized re-treatment strategy for uveal melanoma local recurrences after interventional radiotherapy (brachytherapy): single institution experience and systematic literature review

Purpose

To report the results of a patient’s tailored therapeutic approach using a second course of interventional radiotherapy (brachytherapy) in patients with locally recurrent uveal melanoma.

Material and methods

Patients who had already undergone ocular brachytherapy treated at our IOC (Interventional Oncology Center) were considered. Five patients who has received a second course of treatment with a plaque after local recurrences were included in our study. Re-irradiation was performed with Ruthenium-106 (prescribed dose to the apex 100 Gy) or with Iodine-125 plaques (prescribed dose to the apex 85 Gy). Moreover, a systematic literature search was conducted through three electronic databases, including Medline/PubMed, Scopus, and Embase.

Results

All patients were initially treated with Ruthenium-106 plaque; the re-irradiation was performed with Ruthenium-106 plaque in three cases and with Iodine in two cases. Mean time between the first and the second plaque was 56.8 months (range, 25-93 months). Local tumor control rate was 100%, no patient underwent secondary enucleation owing to re-treatment failure. Distant metastasis occurred in 1 patient after 6 months from re-treatment. After a median follow-up of 44.2 months (range, 26-65 months) from re-treatment, all patients experienced worsening of the visual acuity (median visual acuity was 0.42 at time of recurrence and decline to 0.24 at the most recent follow-up); cataract occurred in two cases, no patient developed scleral necrosis. We considered 2 papers for a systematic review.

Conclusions

In selected cases, especially in presence of marginal local recurrence, a personalized re-treatment strategy with a plaque may offer high probability of tumor control and organ preservation but worsening of visual acuity.

Iodine-125 Episcleral Plaque Brachytherapy for AJCC T4 Posterior Uveal Melanoma: Clinical Outcomes in 158 Patients

Background/Aims

The aim of this study is to report the burden of ocular morbidity following iodine-125 episcleral plaque brachytherapy (EPBT) in the treatment of American Joint Committee on Cancer (AJCC) T4-staged posterior uveal melanoma (PUM).

Methods

Clinical records of patients with T4-staged PUM treated with ¹²⁵I EPBT were analyzed for incidence of treatment failure and radiation-induced complications.

Results

Cumulative incidence of local treatment failure was 9% (95% CI 5-15%) at 5 years and was associated with decreased tumor height (HR = 0.78; p = 0.01). Cumulative incidence of enucleation at 5 years was 21% and was correlated with worsening baseline visual acuity (HR = 1.42; p = 0.05). Increasing patient age was associated with higher rates of vitreous hemorrhage (HR = 1.03; p = 0.02) and cataract surgery (HR = 1.05; p < 0.001). Increased tumor height was associated with higher rates of neovascular glaucoma (HR = 1.16; p = 0.03) and vitreous hemorrhage (HR = 1.23; p < 0.001).

Conclusion

¹²⁵I EPBT is an effective treatment for T4-staged PUM and achieves high rates of local control. Treatment failure appears to be more common among minimally elevated tumors. Other causes of ocular morbidity were associated with increasing tumor height, patient age, and baseline visual acuity.

Proton beam therapy for cancer in the era of precision medicine

Precision radiotherapy, which accurately delivers the dose on a tumor and confers little or no irradiation to the surrounding normal tissue and organs, results in maximum tumor control and decreases the toxicity to the utmost extent. Proton beam therapy (PBT) provides superior dose distributions and has a dosimetric advantage over photon beam therapy. Initially, the clinical practice and study of proton beam therapy focused on ocular tumor, skull base, paraspinal tumors (chondrosarcoma and chordoma), and unresectable sarcomas, which responded poorly when treated with photon radiotherapy. Then, it is widely regarded as an ideal mode for reirradiation and pediatrics due to reducing unwanted side effects by lessening the dose to normal tissue. During the past decade, the application of PBT has been rapidly increasing worldwide and gradually expanding for the treatment of various malignancies. However, to date, the role of PBT in clinical settings is still controversial, and there are considerable challenges in its application. We systematically review the latest advances of PBT and the challenges for patient treatment in the era of precision medicine.

Proton Beam Irradiation: A Safe Procedure in Postequatorial Extraocular Extension From Uveal Melanoma

PURPOSE

This study was performed to show long-term outcomes concerning metastasis rates and local recurrence rates after primary proton beam therapy in uveal melanoma with posterior extraocular extension (EOE) with the main focus on optic nerve invasion.

DESIGN

Retrospective case series.

METHODS

All patients treated with primary proton beam therapy for choroidal or ciliary body melanoma with posterior EOE between July 1998 and August 2010 were included. EOE was detected either upon sonography at primary examination or during the surgical application of tantalum clips onto the sclera. Ultrasound was performed in each patient before surgery, and if EOE was detected, a magnetic resonance imaging (MRI) scan was performed to confirm EOE. All patients with tumors exceeding 6 mm in thickness or abutting the optic disc received a 1.5 Tesla MRI scan after clip surgery. To assess EOE during follow-up, either ultrasound examinations or-if initially detected only by MRI-MRI scans were performed during follow-up.

RESULTS

A total of 27 patients underwent primary proton beam therapy. The EOE was separated into 3 growth types: optic nerve infiltration in 10 patients, vortex vein infiltration in 9 patients, and transscleral growth postequatorially in 8 patients. No local recurrences were found during the overall median follow-up of 80 months (11-168 months). Metastasis rates correlated with AJCC stages but not EOE volume.

CONCLUSION

This study shows that posterior EOE can safely be treated by proton beam therapy, even if the optic nerve is infiltrated. MRI enables safe detection of optic nerve invasion.

[CyberKnife®: new treatment option for uveal melanoma]

BACKGROUND

CyberKnife® stereotactic radiosurgery is a new treatment option for uveal melanoma.

OBJECTIVE

This review outlines the technique of robot-assisted CyberKnife® therapy, as well as the pros and cons in the treatment of uveal melanoma.

METHODS

The study provides a PubMed literature review and own preliminary clinical experiences.

RESULTS

CyberKnife® therapy for choroidal and ciliary body melanomas shows comparable results concerning local tumor control and overall survival matching those of conventional therapies. With only low complication rates, a high level of quality of life can be conserved by possible preservation of visual acuity as well as the ocular globe.

CONCLUSION

Stereotactic radiosurgery using CyberKnife® seems to be an efficient and safe therapeutic option for malignant melanomas affecting the choroid and ciliary body. Comparative studies with conventional radiation strategies are now a high priority.

Adjuvant Ab Interno Tumor Treatment After Proton Beam Irradiation

PURPOSE

This study was performed to show long-term outcomes concerning globe preservation in uveal melanoma patients after proton beam therapy with the main focus on outcomes according to different adjuvant ab interno surgical procedures.

DESIGN

Retrospective cohort study.

METHODS

All patients treated with primary proton beam therapy for choroidal or ciliary body melanoma between June 1998 and June 2015 were included.

RESULTS

A total of 2499 patients underwent primary proton beam therapy, with local tumor control and globe preservation rates of 95.9% and 94.8% after 5 years, respectively. A total of 110 (4.4%) patients required secondary enucleation. Unresponsive neovascular glaucoma was the leading cause of secondary enucleation in 78 of the 2499 patients (3.1%). The 5-year enucleation-free survival rate was 94.8% in the endoresection group, 94.3% in the endodrainage group, and 93.5% in the comparator group. The log-rank test showed P = .014 (comparator group vs endoresection group) and P = .06 (comparator group vs endodrainage-vitrectomy group). Patients treated with endoresection or endodrainage-vitrectomy developed less radiation retinopathy (30.5% and 37.4% after 5 years, P = .001 and P = .048 [Kaplan-Meier], respectively) and less neovascular glaucoma (11.6% and 21.3% after 5 years, P = .001 and P = .01 [Kaplan-Meier], respectively) compared with the comparator group (52.3% radiation retinopathy and 57.8% neovascular glaucoma after 5 years).

CONCLUSION

This study suggests that in larger tumors the enucleation and neovascular glaucoma rates might be reduced by adjuvant surgical procedures. Although endoresection is the most promising adjuvant treatment option, the endodrainage-vitrectomy is recommended in patients who are ineligible for endoresection.

Repeat Episcleral Plaque Brachytherapy: Clinical Outcomes in Patients Treated for Locally Recurrent Posterior Uveal Melanoma

PURPOSE

To report the outcomes of survival, local control, visual acuity, and eye retention in patients treated with repeat episcleral plaque brachytherapy (EPBT) for locally recurrent posterior uveal melanoma (PUM).

DESIGN

Retrospective, interventional case series.

METHODS

Setting: Institutional.

PATIENT POPULATION

A total of 1201 patients that underwent iodine-125 (I-125) EPBT as primary treatment for PUM between 1985 and 2015.

INCLUSION CRITERIA

Development of locally recurrent disease and retreatment with I-125 EPBT.

OBSERVATION PROCEDURES

Clinical records review.

MAIN OUTCOME MEASURES

Visual acuity, Kaplan-Meier estimates of survival, local control, metastasis, and loss of the eye over the duration of follow-up.

RESULTS

Twenty-seven patients (13 men) met our inclusion criteria. Median (range) follow-up from initial treatment was 100 months (14-365 months), while median time to local recurrence was 43 months (9-185 months). Median (range) follow-up after retreatment was 47 months (3-120 months). Kaplan-Meier estimate for local control at 5 years was 77.2% (95% confidence interval [CI], 53.29%-89.91%). All marginal recurrences were successfully retreated whereas 6 of 15 patients with central recurrence developed subsequent re-recurrence following salvage EPBT. Median (range) visual acuity was 20/70 (20/20 to counting fingers at 1 foot) at time of recurrence and declined to counting fingers (20/25 to hand motion) at the most recent follow-up examination. Kaplan-Meier estimate for absence of metastatic disease at 5 years was 78.5% (95% CI, 54.77%-90.70%).

CONCLUSIONS

Repeat I-125 EPBT offers a viable alternative to enucleation in patients with local recurrence of PUM, yielding high rates of local control with predictable decline in visual acuity.

The biology of uveal melanoma

Uveal melanoma (UM), a rare cancer of the eye, is distinct from cutaneous melanoma by its etiology, the mutation frequency and profile, and its clinical behavior including resistance to targeted therapy and immune checkpoint blockers. Primary disease is efficiently controlled by surgery or radiation therapy, but about half of UMs develop distant metastasis mostly to the liver. Survival of patients with metastasis is below 1 year and has not improved in decades. Recent years have brought a deep understanding of UM biology characterized by initiating mutations in the G proteins GNAQ and GNA11. Cytogenetic alterations, in particular monosomy of chromosome 3 and amplification of the long arm of chromosome 8, and mutation of the BRCA1-associated protein 1, BAP1, a tumor suppressor gene, or the splicing factor SF3B1 determine UM metastasis. Cytogenetic and molecular profiling allow for a very precise prognostication that is still not matched by efficacious adjuvant therapies. G protein signaling has been shown to activate the YAP/TAZ pathway independent of HIPPO, and conventional signaling via the mitogen-activated kinase pathway probably also contributes to UM development and progression. Several lines of evidence indicate that inflammation and macrophages play a pro-tumor role in UM and in its hepatic metastases. UM cells benefit from the immune privilege in the eye and may adopt several mechanisms involved in this privilege for tumor escape that act even after leaving the niche. Here, we review the current knowledge of the biology of UM and discuss recent approaches to UM treatment.

Uveal melanoma: epidemiology, etiology, and treatment of primary disease

Uveal melanoma (UM) is the most common intraocular malignancy and arises from melanocytes in the iris, ciliary body, or choroid. Early diagnosis and local treatment is crucial, as survival correlates with primary tumor size. However, approximately 50% of patients will develop metastatic disease with 6-12 months' survival from metastatic diagnosis. Genomic analyses have led to the development of gene-expression profiles that effectively predict metastatic progression; unfortunately, no adjuvant therapy has been shown to prolong survival to date. New insights into the molecular biology of UM have found frequent activating mutations in genes encoding for the G-protein α-subunit, GNAQ and GNA11, and improved understanding of the downstream signaling pathways MAPK, PI3K/Akt, and Hippo have afforded an array of new targets for treatment of this disease. Studies are under way with rationally developed regimens targeting these pathways, and novel agents are under development. We review the diagnosis, management, and surveillance of primary UM and the adjuvant therapy trials under way.

Early outcomes of uveal melanoma treated with intraoperative ultrasound guided brachytherapy using custom built plaques

PURPOSE

To report early outcomes of patients with uveal melanoma treated with Eye Physics iodine-125 episcleral plaque therapy using modern biopsy techniques and intraoperative ultrasound guidance at our institution.

METHODS AND MATERIALS

A retrospective chart review was conducted for 48 consecutive patients with uveal melanoma who were treated with Eye Physics plaque brachytherapy performed by 1 ocular oncologist. All patients underwent intraoperative ultrasound for image guidance of plaque placement. A dose of 85 Gy was prescribed to the apical height of the tumor or 5 mm from the inner sclera, whichever was greater. Forty-five patients underwent biopsy. Visual acuity, complication data, and recurrence rates were recorded.

RESULTS

Median age at presentation was 63.0 years (range, 19-86 years). Median follow-up was 21.6 months. Median tumor apical height was 3.3 mm (range, 1.8-11.5 mm). Median dose at apex for tumor height >5 mm was 85.0 Gy and 142.5 Gy for tumor height ≤5 mm. Mean percent decrease in tumor height from baseline at 12, 24, and 36 months was 39.6%, 51.8%, and 53.8%, respectively. At 24 months, 19/23 (82.6%) patients maintained vision within 3 lines of baseline visual acuity. Twelve patients developed radiation retinopathy, 6 of whom were treated with anti-vascular endothelial growth factor therapy in the context of a clinical trial. No patients to date have local failure. Three patients are alive with confirmed hepatic metastases.

CONCLUSIONS

We reported 0% early local failure rate and steady reduction in tumor height in 48 patients with uveal melanoma, ranging from small to large size, who were treated with Eye Physics iodine-125 episcleral plaque therapy using intraoperative ultrasound guidance. This promising result emphasizes the importance of image guided brachytherapy with intraoperative ultrasound at the time of plaque placement.

Antiangiogenic or Corticosteroid Treatment in Patients With Radiation Maculopathy After Proton Beam Therapy for Uveal Melanoma

PURPOSE

To reveal differences or advantages in regard to different treatment options after proton beam therapy for uveal melanoma.

DESIGN

Retrospective, comparative, interventional case series.

METHODS

All patients receiving intravitreal treatment between January 2011 and July 2014 for radiation maculopathy after proton beam therapy were included. Excluded were all patients who required re-irradiation, vitrectomies, or tumor resections; and those whose treatment was performed for potentially other reasons, such as radiation-induced optic neuropathy, or where visual outcome was influenced by tumor growth under the macula or macular ischemia. Minimum follow-up was 12 months after last injection.

RESULTS

Of 78 patients, 38 (48.7%) received bevacizumab injections, 35 (44.9%) triamcinolone acetonide injections, and 5 (6.4%) a dexamethasone implant. In the bevacizumab group visual acuity improved in 11 patients (28.9%) by 0.25 logMAR (0.1-0.4 logMAR) and remained stable in 24 patients (63.2%) 4 weeks after injection. In the triamcinolone group visual acuity showed improved outcomes in 10 patients (28.6%) by 0.25 logMAR (0.1-0.4 logMAR) and stability in function in 20 patients (57.1%). Four weeks after dexamethasone implantation visual acuity remained stable in 4 patients (80%). No differences among the groups were detected regarding functional outcome or reduction in central foveal thickness.

CONCLUSIONS

This study showed that antiangiogenic or corticosteroid intravitreal treatment led to reduced central foveal thickness and visual improvement in some patients without showing differences or advantages. Therefore a patient-specific treatment choice can be recommended.