ROLE OF VITREORETINAL SURGERY IN MAXIMIZING TREATMENT OUTCOME FOLLOWING COMPLICATIONS AFTER PROTON THERAPY FOR UVEAL MELANOMA

Ocular Complications of Radiotherapy in Uveal Melanoma

Uveal melanoma is the most common primary malignant intraocular tumor in adults. Radiation therapy has replaced enucleation and is now the preferred treatment in most cases. Nonetheless, around 70% of patients develop radiation-related complications, some of which are vision-threatening. The objective of this review is to present the most important complications associated with radiotherapy in the treatment of uveal melanoma and their pathogenesis, incidence, risk factors, and available preventive and therapeutic measures. The most common complications are cataracts, with a reported incidence ranging from 4% to 69%, and radiation retinopathy, reported in 5-68% of cases. Radiation-related complications are responsible for approximately half of secondary enucleations, the leading cause being neovascular glaucoma. A poor visual outcome is mainly associated with the presence of radiation retinopathy and radiation optic neuropathy. Therapeutic options are available for the majority of complications with the notable exception of optic neuropathy. However, many studies report a final visual acuity of less than 20/200 in more than 60% of treated eyes. Reducing complication rates can be achieved by lowering the dose of radiation, with the use of eccentric, customized plaques and careful planning of the irradiation delivery in order to protect structures vital to vision and by associating radiation therapy with other methods with the aim of reducing tumor volume.

Feasibility, Method and Early Outcome of Image-Guided Volumetric Modulated Arc Radiosurgery Followed by Resection for AJCC Stage IIA–IIIB High-Risk Large Intraocular Melanoma

Simple Summary

The aim of this trial was to define one optimal contemporary treatment procedure for large intraocular melanoma. Radiosurgery is a highly effective treatment in cancer. In this trial, all consecutive patients with large intraocular melanoma treated with multimodality treatment, comprising 4D image-guided volumetric modulated arc radiosurgery procedure followed by resection, were evaluated. In the short-term follow-up there was no clinical toxicity due to external beam radiation therapy, and no local tumor recurrence. In 98% of the cases, the eye bulb could be maintained with partial residual visual acuity in the mean follow-up of 18 months. The outcome estimates one optimal treatment procedure for high-risk, large intraocular melanoma, with excellent results in the first follow-up.

Abstract

The main objective of this prospective observational study was the characterization of the feasibility and early outcome of image-guided (IG) volumetric modulated arc (VMAT) radiosurgery (SRS) followed by resection for patients with large intraocular melanoma. Our study included consecutive patients with unfavorable-risk melanoma, enrolled in an ophthalmic oncology center. IG-VMAT-SRS was applied by high-resolution 4D image guidance and monitoring. Current stereotactic technique parameters were evaluated for comparison. Side effects and eye function, based on a 5-point CTC assessment score, were quantified. In patients with tumors located more than 0.7–1 mm apart from the optic nerve, partial to complete volume-sparing of the optic nerve head could be achieved. In 95.5% of this subgroup, the vitality of the optic nerve and vision could be preserved by the multimodality-treatment approach (mean follow-up: 18 months (7.5–36 months)). The advanced technology of stereotactic radiotherapy demonstrated the achievability of steep dose gradients around the high-dose volume, with 4D-IG-VMAT dose application. These results enforce IG-VMAT-SRS followed by resection as one of the major therapeutic options for patients with large intraocular melanoma. The combination of 4D-IG high-precision SRS and resection provides an effective treatment for large intraocular melanoma, with few side effects, and enables an eye bulb and even vision preserving modus operandi.

Vitreoretinal Surgery in the Prevention and Treatment of Toxic Tumour Syndrome in Uveal Melanoma: A Systematic Review

Toxic tumour syndrome (TTS) is a particularly aggressive form of secondary vasculopathy occurring after radiation therapy of uveal melanoma due to the persistence of the necrotic tumour mass inside the eye. The development of TTS confers a particularly unfavourable functional and anatomical ocular prognosis, ultimately requiring enucleation in most cases if untreated. Vitreoretinal (VR) surgery has been successfully applied for treatment and prevention of TTS using both resecting and non-resecting techniques. In this systematic review, we aim to define characteristics of uveal melanomas benefiting the most from secondary VR surgery and to outline the optimal type and timing of VR intervention in such cases. Analysis of the literature reveals that endoresection should be performed within 3 months after radiotherapy to tumours thicker than 7 mm and with a largest basal diameter between 8 mm and 15 mm with post-equatorial location, especially after proton beam treatment. Alternatively, endodrainage remains a valid therapeutic option in eyes with macula-off retinal detachment, tumour diameter larger than 15 mm or ciliary body involvement. VR surgery can be successful in the management of TTS following radiotherapy for uveal melanoma when timing and indication are appropriately evaluated.

TRPM8 Activation via 3-Iodothyronamine Blunts VEGF-Induced Transactivation of TRPV1 in Human Uveal Melanoma Cells

In human uveal melanoma (UM), tumor enlargement is associated with increases in aqueous humor vascular endothelial growth factor-A (VEGF-A) content that induce neovascularization. 3-Iodothyronamine (3-T₁AM), an endogenous thyroid hormone metabolite, activates TRP melastatin 8 (TRPM8), which blunts TRP vanilloid 1 (TRPV1) activation by capsaicin (CAP) in human corneal, conjunctival epithelial cells, and stromal cells. We compare here the effects of TRPM8 activation on VEGF-induced transactivation of TRPV1 in an UM cell line (92.1) with those in normal primary porcine melanocytes (PM) since TRPM8 is upregulated in melanoma. Fluorescence Ca²⁺-imaging and planar patch-clamping characterized functional channel activities. CAP (20 μM) induced Ca²⁺ transients and increased whole-cell currents in both the UM cell line and PM whereas TRPM8 agonists, 100 μM menthol and 20 μM icilin, blunted such responses in the UM cells. VEGF (10 ng/ml) elicited Ca²⁺ transients and augmented whole-cell currents, which were blocked by capsazepine (CPZ; 20 μM) but not by a highly selective TRPM8 blocker, AMTB (20 μM). The VEGF-induced current increases were not augmented by CAP. Both 3-T₁AM (1 μM) and menthol (100 μM) increased the whole-cell currents, whereas 20 μM AMTB blocked them. 3-T₁AM exposure suppressed both VEGF-induced Ca²⁺ transients and increases in underlying whole-cell currents. Taken together, functional TRPM8 upregulation in UM 92.1 cells suggests that TRPM8 is a potential drug target for suppressing VEGF induced increases in neovascularization and UM tumor growth since TRPM8 activation blocked VEGF transactivation of TRPV1.

Phthisis Bulbi-a Clinicopathological Perspective

Phthisis bulbi denotes end-stage eye disease characterized by shrinkage and disorganization of the eye with the resultant functional loss. The major factors associated with the pathogenesis of phthisis are hypotony, deranged blood-ocular barriers, and inflammation. Common causes include trauma, surgery, infection, inflammation, malignancy, retinal detachment, and vascular lesions. A phthisical globe shows a small squared off shape, opaque and thickened cornea, thickened sclera, neovascularization of iris, cataract, cyclitic membrane, ciliochoroidal detachment, and retinal detachment. Microscopic features include internal disorganization, inflammatory reaction, a reactive proliferation of various cells, calcification, and ossification. Early treatment of the causative etiology is the best strategy available to avoid an eye from going into phthisis. A phthisical eye has no visual potential and cosmetic rehabilitation or symptomatic relief of pain remains the mainstay in the management. The authors present a comprehensive review of the etiopathogenesis, pathology, clinical features, and management of the end-stage ocular disease.

Incidence and indications for pars plana vitrectomy following the treatment of posterior uveal melanomas in Scotland

BACKGROUND

Globe-sparing treatments such as plaque brachytherapy, local or endoresection, and proton beam therapy (PBT) are the treatments of choice for posterior uveal melanoma. However, both early and late complications can arise from these techniques, including vitreous haemorrhage (VH) and retinal detachment (RD). Choroidal melanomas in Scotland are managed by a single unit, the Scottish Ocular Oncology Service (SOOS).

METHODS

Indications and outcomes from surgery were analysed for patients undergoing vitrectomy following treatment for uveal melanoma in the SOOS between 1998 and 2013.

RESULTS

Seventeen from 715 cases (2.4%) required vitrectomy, of which 8/445 (1.8%) followed plaque brachytherapy, 7/43 (16.3%) combined local resection and brachytherapy, and 2/227 (0.9%) PBT. Case notes were reviewed for 16/17 cases, with surgery indicated for VH in 10 (63%), RD in 5 (31%), and combined VH/RD in 1 (6%). The median interval from initial tumour treatment to vitrectomy was 5.8 months (range 10 days to 8.8 years). Ten (63%) required early vitrectomy (within 6 months), of which the majority (70%) followed combined resection/brachytherapy. Six (37%) required late vitrectomy (after 6 months), of which all were non-clearing VH following plaque brachytherapy, with proliferative retinopathy in 4/6 (67%), and tumour recurrence in 2/6 (33%). Overall vision improved in 8 eyes (50%), remained the same in 2 (12.5%), and deteriorated in 6 (37.5%).

CONCLUSIONS

Early vitrectomy was most commonly indicated for RD following local resection, and late vitrectomy for VH due to radiation retinopathy. The majority of patients undergoing vitrectomy gained or maintained vision.

Endodrainage, Tumor Photocoagulation, and Silicone Oil Tamponade for Primary Exudative Retinal Detachment due to Choroidal Melanoma Persisting after Proton Beam Therapy

BACKGROUND

Choroidal melanoma is frequently accompanied by an exudative retinal detachment that can persist after proton beam therapy. This study investigates whether vitrectomy without tumor resection improves the clinical outcome.

METHODS

This is a retrospective interventional case series. Twenty patients with choroidal melanoma with exudative retinal detachment involving the macula were treated by vitrectomy, endodrainage, photocoagulation, and silicone oil tamponade after proton beam therapy.

RESULTS

The mean follow-up was 38.4 months (median 21.5, range 12.0-122.0). The mean time between proton beam therapy and surgery was 4.5 months (range 0.1-9.2). Reattachment was achieved in 95% of the patients after one vitrectomy. One patient was lost to follow-up because enucleation was performed after 45.9 months due to a secondary glaucoma. Mean visual acuity decreased from 1.1 to 1.8 logMAR before vitrectomy and after 4 years, respectively. No patient showed local tumor recurrence. Metastatic disease was present in 1 patient after 15.2 months, and this patient died after 19.2 months.

CONCLUSION

Vitrectomy is indicated after therapeutic proton beam irradiation in patients who present with persisting exudative retinal detachment involving the macula and high local or systemic risk factors for hemorrhagic complications, thus excluding endoresection.

Preliminary results of proton radiotherapy for choroidal melanoma - the Kraków experience

AIM OF THE STUDY

The objective of the study was to present the preliminary results of proton radiotherapy as a method for treating 15 patients with choroidal melanoma.

MATERIAL AND METHODS

The proton radiotherapy was administered using beams providing energy levels of 60 MeV, which ensures a clinical range of 28.4 mm. In addition, the beam has a very narrow penumbra of 1.3 mm and a sharp distal dose fall-off. All patients received the dose of 60 CGE (cobalt gray equivalent) given to the PTV (planning target volume). This dose was administered in 4 fractions over 4 successive days of treatment.

RESULTS

The tumour had regressed in 8 patients (53.3%) and remained stable in 3 patients (20%). The large tumours in another 3 patients (20%) were removed during vitrectomy (endoresection), which increased the number of patients with tumour regression up to 11 (73.3%). In the case of 1 patient, despite intraocular tumour regression occurring the choroidal melanoma had spread multifocally into the orbit, which necessitated orbit exenteration. The results ensured that the eyeballs of 14 patients (93.3%) could be saved. The follow-up period for the 15 patients ranged between 8 and 26 months (average: 17.4 months, median: 19 months). In this period some side effects were noted: an increase in intraocular pressure, retinal detachment, cataract, maculopathy, neuropathy and vitreous haemorrhaging.

CONCLUSIONS

The preliminary results confirm that proton radiotherapy is an effective method for treating patients with choroidal melanoma. This method ensures an eyeball preservation rate of 93%, with the vision function of 80% of the patients being saved.

Neuroanatomy of apathy and disinhibition in frontotemporal lobar degeneration

OBJECTIVE

To investigate the neural basis for the behavioral symptoms of frontotemporal lobar degeneration (FTLD) that cause the greatest caregiver distress.

BACKGROUND

FTLD is a progressive neurodegenerative disease associated with behavioral disturbances. Group studies have related these behaviors to volume loss on MRI.

METHODS

Forty caregivers of patients with the clinical diagnosis of FTLD completed the Neuropsychiatric Inventory. Twelve neuropsychiatric symptoms and the associated caregiver distress were assessed. Optimized voxel-based morphometry identified significant atrophy in subgroups of FTLD patients with isolated behavioral symptoms corresponding to the most distressing behaviors, and we correlated cortical atrophy directly with these distressing behavioral disorders in an unbiased group analysis.

RESULTS

The greatest stressors for caregivers were apathy and disinhibition (p < 0.005 for both contrasts). Partially distinct areas of cortical atrophy were associated with these behaviors in both individual patients with these symptoms and group-wide analyses, including the dorsal anterior cingulate cortex and dorsolateral prefrontal cortex in apathetic patients, and the medial orbital frontal cortex in disinhibited patients.

CONCLUSIONS

Caregiver stress in families of FTLD patients is due in large part to apathy and disinhibition. The anatomic distribution of cortical loss corresponding to these distressing social behaviors includes partially distinct areas within the frontal lobe.