Predictive risk factors for radiation retinopathy and optic neuropathy after proton beam therapy for uveal melanoma

PTCOG Ocular Statement: Expert Summary of Current Practices and Future Developments in Ocular Proton Therapy

Although rare cancers, ocular tumors are a threat to vision, quality of life, and potentially life expectancy of a patient. Ocular proton therapy (OPT) is a powerful tool for successfully treating this disease. The Particle Therapy Co-Operative Ocular Group) formulated an Evidence and Expert-Based Executive Summary of Current Practices and Future Developments in OPT: comparative dosimetric and clinical analysis with the different OPT systems is essential to set up planning guidelines, implement best practices, and establish benchmarks for eye preservation, vision, and quality of life measures. Contemporary prospective trials in select subsets of patients (eg, tumors near the optic disc and/or macula) may allow for dosimetric and clinical analysis between different radiation modalities and beamline systems to evaluate differences in radiation delivery and penumbra, and resultant tumor control, normal tissue complication rates, and overall clinical cost-effectiveness. To date, the combination of multimodal imaging (fundus photography, ultrasound, etc), ophthalmologist assessment, and clip surgery with radiation planning have been keys to successful treatment. Increased use of three-dimensional imaging (computed tomography/magnetic resonance imaging) is anticipated although its spatial resolution might be a limiting factor (eg, detection of flat diffuse tumor parts). Commercially produced ocular treatment-planning systems are under development and their future use is expected to expand across OPT centers. Future continuity of OPT will depend on the following: (1) maintaining and upgrading existing older dedicated low-energy facilities, (2) maintaining shared, degraded beamlines at large proton therapy centers, and (3) developing adapted gantry beams of sufficient quality to maintain the clinical benefits of sharp beam conformity. Option (1) potentially offers the sharpest beams, minimizing impact on healthy tissues, whereas (2) and (3) potentially offer the advantage of substantial long-term technical support and development as well as the introduction of new approaches. Significant patient throughputs and close cooperation between medical physics, ophthalmology, and radiation therapy, underpinned by mutual understanding, is crucial for a successful OPT service.

Comparison of stereotactic radiotherapy and protons for uveal melanoma patients

Background and purpose

Uveal melanoma (UM) is the most common primary ocular malignancy. We compared fractionated stereotactic radiotherapy (SRT) with proton therapy, including toxicity risks for UM patients.

Materials and methods

For a total of 66 UM patients from a single center, SRT dose distributions were compared to protons using the same planning CT. Fourteen dose-volume parameters were compared in 2-Gy equivalent dose per fraction (EQD2). Four toxicity profiles were evaluated: maculopathy, optic-neuropathy, visual acuity impairment (Profile I); neovascular glaucoma (Profile II); radiation-induced retinopathy (Profile III); and dry-eye syndrome (Profile IV). For Profile III, retina Mercator maps were generated to visualize the geographical location of dose differences.

Results

In 9/66 cases, (14 %) proton plans were superior for all dose-volume parameters. Higher T stages benefited more from protons in Profile I, especially tumors located within 3 mm or less from the optic nerve. In Profile II, only 9/66 cases resulted in a better proton plan. In Profile III, better retina volume sparing was always achievable with protons, with a larger gain for T3 tumors. In Profile IV, protons always reduced the risk of toxicity with a median RBE-weighted EQD2 reduction of 15.3 Gy.

Conclusions

This study reports the first side-by-side imaging-based planning comparison between protons and SRT for UM patients. Globally, while protons appear almost always better regarding the risk of optic-neuropathy, retinopathy and dry-eye syndrome, for other toxicity like neovascular glaucoma, a plan comparison is warranted. Choice would depend on the prioritization of risks.

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.

Surgical Approach in Intraocular Tumors

Surgery in intraocular tumors is done for excision/biopsy and the management of complications secondary to the treatment of these tumors. Excision/biopsy of intraocular tumors can be done via fine-needle aspiration biopsy (FNAB), transretinal biopsy (TRB), partial lamellar sclerouvectomy (PLSU), and endoresection. FNAB, TRB, and PLSU can be used in tumors that cannot be diagnosed by clinical examination and other ancillary testing methods. PLSU is employed in tumors involving the iridociliary region and choroid anterior to the equator. Excisional PLSU is performed for iridociliary and ciliary body tumors with less than 3 clock hours of iris and ciliary body involvement and choroidal tumors with a base diameter less than 15 mm. However, for biopsy, PLSU can be employed with any size tumor. Endoresection is a procedure whereby the intraocular tumor is excised using vitrectomy techniques. The rationale for performing endoresection is based on the fact that irradiated uveal melanomas may cause complications such as exudation, neovascular glaucoma, and intraocular pigment and tumor dissemination (toxic tumor syndrome), and removing the dead tumor tissue may contribute to better visual outcome. Endoresection is recommended 1-2 weeks after external radiotherapy. Pars plana vitrectomy is also used in the management of complications including vitreous hemorrhage, retinal detachment, and epiretinal membrane that can occur after treatment of posterior segment tumors using radiotherapy and transpupillary thermotherapy. It is important to make sure the intraocular tumor has been eradicated before embarking on such treatment.

Treatment and prophylaxis of radiation optic neuropathy: A systematic review and meta-analysis

PURPOSE

Radiation optic neuropathy (RON) generally follows radiation therapy that exceed 50 Gy to the visual axis and occurs within three years of therapy. Currently, there are no universally accepted treatments or prophylaxis for RON. The review aimed to examine the efficacy of all treatments and prophylaxis for RON.

METHODS

MEDLINE, Embase, the Cochrane Library, and gray literature were searched to December 2020. Studies on treatment(s) and/or prophylaxis of RON were included. Results were meta-analyzed using a random-effects model. Primary outcomes included the proportions of patients who experienced improvement, no change, or worsening of visual acuity (VA) for each treatment. Secondary outcome was the incidence of RON for studies on prophylaxis.

RESULTS

Overall, 50 studies (n = 5397) were included. Meta-analysis (n = 1752) showed significantly lower incidence of RON in patients who underwent intravitreal anti-VEGF prophylaxis compared to control (RR 0.64, 95%CI [0.48, 0.86]) for uveal melanoma. Intravitreal anti-VEGF injections (n = 68), hyperbaric oxygen therapy alone (n = 14), and pentoxifylline (n = 5) resulted in improved or stable vision ≤1 logMAR in 54.5%, 42.9%, and 40.0% of patients, respectively. Systemic corticosteroids (n = 82), anticoagulants (n = 12), and systemic bevacizumab (n = 7) showed improved or stable vision ≤1 logMAR in 17.1%, 33.3%, and 14.3% of patients, respectively. Overall risk of bias was low, but evidence was limited to retrospective studies.

CONCLUSION

Intravitreal anti-VEGF injections reduced incidence of RON in irradiated uveal melanoma patients. Systemic corticosteroids, systemic bevacizumab, and warfarin alone are likely ineffective treatments. Early hyperbaric oxygen therapy and intravitreal anti-VEGF injections were most effective among those investigated and require further investigation.

OCT-angiography for the diagnosis of radiation maculopathy in patients treated with proton beam therapy: A 2-year prospective study

PURPOSE

Radiation maculopathy (RM) is the leading cause of visual acuity (VA) loss after proton beam therapy (PBT) of choroidal melanoma. The aim of this study was to assess the value of optical coherence tomography-angiography (OCT-A) for the diagnosis of RM in patients with choroidal melanoma treated with PBT.

MATERIALS & METHODS

This 2-year prospective, descriptive, single-center study included patients treated with PBT for choroidal melanoma. VA measurement, retinography, OCT and OCT-A were performed. Vascular density (VD) in the superficial capillary plexus (SCP), peri-foveal anastomotic ring changes and foveal avascular zone (FAZ) enlargement were studied.

RESULTS

Nineteen patients were included in the study. The median baseline melanoma thickness was 5.7 [3.6-8.1] mm. The median melanoma-to-macula distance was 3.5 [2.6-4.6] mm. The earliest signs of RM identified on retinography were hard exudates developing at 12 [12-24] months, followed by retinal hemorrhages at 18 [12-30] months, found in 88.9% and 77.8% of patients respectively. On OCT, the earliest sign was the onset/progression of cystoid macular edema (CME) at 12 [6-12] months, found in 10 patients (52.6%). On OCT-A, 100% of patients presented with a discontinuity of the perifoveal anastomotic ring and a FAZ enlargement after 12 [6-24] months. After 12 months, a VD loss in the SCP by 11.7% and 10.8% compared to baseline, was found in the macular and foveal areas respectively. A significant negative correlation was found between the VA and the VD in the macular SCP (R = -0.43; p = 0.029).

CONCLUSION

OCT-A is a reliable and effective diagnostic tool for RM in patients with choroidal melanoma treated with PBT.

Predictive factors of radio-induced complications in 194 eyes undergoing gamma knife radiosurgery for uveal melanoma

BACKGROUND AND PURPOSE

To report the factors predictive of radio-induced complications (i.e. radiation retinopathy [RR], radiation papillopathy [RP] and neovascular glaucoma [NVG]) in uveal melanoma (UM) patients undergoing gamma knife radiosurgery (GKR).

MATERIALS AND METHODS

Longitudinal cohort study on patients with UM treated at the Ocular Oncology Service, San Raffaele Scientific Institute, Milan, between June 1994 and November 2018. Data were retrospectively reviewed. Rates of GKR-related complications were reported. Variables associated with each complication were investigated using multivariable Cox models and confirmed by logistic regression analysis. Hazard ratio (HR) and 95% confidence intervals (CI) were reported for significant associations.

RESULTS

One hundred ninety-four patients (99 males, 51%) were included, and 184 tumours were primarily located in the choroid (95%). Median follow-up was 57 months (range 6-286). Local control was achieved in 182 eyes (94%), and 152 eyes (78%) experienced at least one radiation-induced complication. Radiation retinopathy was documented in 67 eyes (35%) after a median of 23 months. Older age (HR = 0.97, 95% CI = 0.95-0.99, p = 0.02) had a protective effect for RR. Radiation papillopathy was diagnosed in 35 eyes (18%) after a median of 14 months after GKR. Macular or peripapillary location (HR = 3.06, 95% CI = 1.52-6.16, p = 0.002) was associated with increased risk of RP, while older age was protective (HR = 0.95, 95% CI = 0.93-0.98, p = 0.001). New-onset NVG was found in 53 eyes (27%), and median onset was 28 months. Tumour thickness (HR = 4.41, 95% CI = 2.23-8.72, p < 0.001) and peripapillary location (HR = 2.78, 95% CI = 1.46-5.27, p = 0.002) were the main risk factors associated with NVG.

CONCLUSION

Understanding factors predictive for radiation-related complications in patients undergoing GKR might help for better counselling and treatment planning.

Assessment of Radiation-Induced Optic Neuropathy in a Multi-Institutional Cohort of Chordoma and Chondrosarcoma Patients Treated with Proton Therapy

Simple Summary

Proton therapy is an effective therapeutic option for the treatment of skull-base tumors that require high radiation doses to be controlled. On rare occasions, patients suffer from radiation-induced optic neuropathy (RION) to the detriment of their post-treatment quality-of-life. We have collected multi-institutional data of 289 skull-base patients having received high doses to the optic apparatus from proton therapy or proton–photon mixed treatments and have observed a RION incidence rate (all grades) of 4.2% (12). We have furthermore confirmed older age and hypertension as risk factors for the onset of this side effect, with tumor involvement or its proximity to the optic apparatus and repeated surgical procedures showing moderate association. Our findings were consolidated into a NTCP model that can support pre-treatment patient segmentation into risk groups and the planning of necessary treatment countermeasures. However, further data and validation are necessary to confirm validity of the model.

Abstract

Radiation-induced optic neuropathy (RION) is a rare side effect following radiation therapy involving the optic structures whose onset is, due to the low amount of available data, challenging to predict. We have analyzed a multi-institutional cohort including 289 skull-base cancer patients treated with proton therapy who all received >45 Gy_RBE to the optic apparatus. An overall incidence rate of 4.2% (12) was observed, with chordoma patients being at higher risk (5.8%) than chondrosarcoma patients (3.2%). Older age and arterial hypertension, tumor involvement, and repeated surgeries (>3) were found to be associated with RION. Based on bootstrapping and cross-validation, a NTCP model based on age and hypertension was determined to be the most robust, showing good classification ability (AUC-ROC 0.77) and calibration on our dataset. We suggest the application of this model with a threshold of 6% to segment patients into low and high-risk groups before treatment planning. However, further data and external validation are warranted before clinical application.

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.

Radiation Retinopathy: Detection and Management Strategies

A gradual shift in trend from primary enucleation to globe salvaging radiation therapy for the management of ocular tumors has resulted in the rise of several post-treatment ocular complications including radiation retinopathy. Radiation retinopathy is a chronic, progressive, and occlusive vasculopathy that can manifest anytime between 1 month to 15 years after starting radiation therapy. The aim of treatment in most of these cases is to prevent further vision loss. Treatment options such as laser photocoagulation, anti-vascular endothelial growth factor and intraviral steroids have been described. However, despite several advances in diagnostic and therapeutic modalities, a significant proportion of eyes with radiation retinopathy eventually go blind. This review summarises some of the clinical features, investigative modalities, and recent therapeutic strategies used in the management of radiation retinopathy.

Prospective Assessment of Early Proton Therapy-Induced Optic Neuropathy in Patients With Intracranial, Orbital or Sinonasal Tumors: Impact of A Standardized Ophthalmological Follow Up

PURPOSE

Proton therapy (PT) can be a good option to achieve tumor control while reducing the probability of radiation induced toxicities compared to X-ray-based radiotherapy. However, there are still uncertainties about the effects of PT on the organs in direct contact with the irradiated volume. The aim of this prospective series was to report 6-month follow-up of clinical and functional optic neuropathy rates of patients treated by proton therapy using a standardized comprehensive optic examination.

METHODS AND MATERIALS

Standardized ophthalmological examinations were performed to analyze subclinical anomalies in a systematic way before treatment and 6 months after the end of proton therapy with: Automatic visual field, Visual evoked potential (VEP) and optic coherence of tomography (OCT).

RESULTS

From October 2018 to July 2020 we analyzed 81 eyes. No significant differences were found in the analysis of the clinical examination of visual functions by the radiation oncologist. However, considering VEP, the impairment was statistically significant for both fibers explored at 30'angle (p:0.007) and 60'angle (p <0.001). In patients with toxicity, the distance of the target volume from the optical pathways was more important with a p-value for 30'VEP at 0.035 and for 60'VEP at 0.039.

CONCLUSIONS

These results confirm uncertainties concerning relative biological effectiveness of proton therapy, linear energy transfer appears to be more inhomogeneous especially in areas close to the target volumes. The follow-up of patients after proton therapy is not an easy process to set up but it is necessary to improve our knowledges about the biological effects of proton therapy in real life. Our study which will continue during the coming years, suggests that follow-up with in-depth examinations such as VEP as a biomarker could improve the detection of early abnormalities.

Radiation-Induced Optical Coherence Tomography Angiography Retinal Alterations in Patients With Nasopharyngeal Carcinoma

Aim: The aim of the study was to investigate the early neurovascular alterations of the retina in radiation encephalopathy (RE) patients with normal-ranged visual acuity after radiotherapy for nasopharyngeal carcinoma.

Methods: Fifty-five RE patients and 54 healthy age-matched subjects were enrolled in this retrospective cross-sectional case–control study. The best corrected visual acuity (LogMAR) of the included eye should not be more than 0. The vessel density and thickness of different locations in the retina were acquired automatically using optical coherence tomography angiography (OCTA). The data were then compared between the RE patients and the controls. The location included the whole retina, the superficial vascular plexus (SVP)/the ganglion cell complex (GCC), the deep vascular plexus (DVP), and the choroid in the macular area, as well as the inside disc and peripapillary area in the optic nerve head (ONH). The risk factors in OCTA retinal impairments were analyzed using a backward multiple linear regression. The relationships between mean deviation (MD) and pattern standard deviation (PSD) in the visual field (VF) and the OCTA parameters were also analyzed in RE patients.

Results: The vessel density of the GCC was significantly reduced in RE patients compared with controls (p = 0.018), and the reductions were mainly shown in the parafoveal (p = 0.049) and perifoveal fields (p = 0.006). The thickness of the GCC was correspondingly reduced (whole image GCC mean thickness: p = 0.044; parafoveal thickness: p = 0.038; perifoveal thickness: p = 0.038). In addition, the sub-foveal choroidal thickness (p = 0.039) was also reduced in RE patients. The vessel density of the GCC (R² = 0.643) and DVP (R² = 0.777) had a significant positive correlation with high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (ApoA1) and had a significant negative correlation with age (GCC: HDL-C, β = 29.89, p = 0.005; ApoA1, β = 78.92, p = 0.002; age, β = −0.886, p = 0.001; DVP: HDL-C, β = 40.09, p = 0.003; ApoA1, β = 62.65, p = 0.013; age, β = −1.31, p = 0.001). The vessel density of the GCC also had a significant negative correlation with apolipoprotein B (ApoB) (β = −32.18, p = 0.006). In the VF, MD had a significant positive correlation with the vessel density inside disc (R² = 0.241, β = 0.304, p = 0.045), whereas PSD showed a significant negative correlation with the vessel density inside disc and the average GCC thickness, respectively (R² = 0.437; vessel density inside disc, β = −0.358, p = 0.004; average GCC thickness, β = −0.510, p < 0.001).

Conclusion: With the aid of OCTA, we found that neurovascular alterations of the retina may exist in RE patients with normal-ranged visual acuity. Herein, we suggest the implementation of OCTA to assist ophthalmologists in the early detection and consistent monitoring of radiation-related eye diseases to avoid delayed diagnosis.

Stereotactic radiosurgery for orbital cavernous venous malformation: a single center's experience for 15 years

BACKGROUND

Stereotactic radiosurgery such as Gamma Knife radiosurgery (GKRS) has been shown to have a good treatment effect for orbital cavernous venous malformation (CVM). However, radiation-induced retinopathy or optic neuropathy is a vision-threatening complication of orbital irradiation. Predicting the post-treatment visual outcome is critical.

METHODS

Clinical and radiological outcomes were investigated in 30 patients who underwent GKRS for orbital CVM between July 2005 and February 2020. Measurement of peripapillary retinal nerve fiber layer (pRNFL) thickness using optical coherence tomography (OCT) was obtained in 14 patients.

RESULTS

The median clinical and radiological follow-up periods were 46.6 months (range, 15.9-105.8) and 27.5 months (range, 15.4-105.8), respectively. Twenty-eight patients underwent multisession (4 fractions) GKRS. The median cumulative marginal dose was 20 Gy (range, 16-24). Two patients underwent single-session GKRS. Marginal doses were 15 Gy and 10.5 Gy in each patient. The volume of CVM decreased in 29 (97%) patients. Visual acuity was improved in 6 (20%) patients and was stable in 22 (73%) patients. Visual field defect and exophthalmos were improved in all patients. Serial investigation of OCT showed no statistically significant difference in pRNFL thickness after GKRS. Patients with normal average pRNFL thickness showed better visual recovery than patients with thin average pRNFL thickness.

CONCLUSIONS

GKRS is an effective and safe treatment option for orbital CVM. The pRNFL thickness before GKRS can be a prognostic indicator for visual recovery in orbital CVM after GKRS.

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.

Visual outcomes of proton beam therapy for choroidal melanoma at a single institute in the Republic of Korea

We evaluate the ocular effects of proton beam therapy (PBT) in a single institution, in Korea, and identify factors contributing to decreasing visual acuity (VA) after PBT. A total of 40 patients who received PBT for choroidal melanoma (2009‒2016) were reviewed. Dose fractionation was 60‒70 cobalt gray equivalents (CGEs) over five fractions. Complete ophthalmic examinations including funduscopy and ultrasonography were performed at baseline and at 3, 6, and 12 months after PBT, then annually thereafter. Only patients with at least 12 months follow-up were included. During the follow-up, consecutive best-corrected visual acuity (BCVA) changes were determined, and univariate and multivariate logistic regression analyses were performed to identify predictors for VA loss. The median follow-up duration was 32 months (range: 12‒82 months). The final BCVA of nine patients was > 20/40. The main cause of vision loss was intraocular bleeding, such as neovascular glaucoma or retinal hemorrhage. Vision loss was correlated with the tumor size, tumor distance to the optic disc or fovea, maculae receiving 30 CGEs, optic discs receiving 30 CGEs, and retinas receiving 30 CGEs. Approximately one-third of PBT-treated choroidal melanoma patients with good pretreatment BCVA maintained their VA. The patients who finally lost vision (VA < count fingers) usually experienced rapid declines in VA from 6‒12 months after PBT. Tumor size, tumor distance to the optic disc or fovea, volume of the macula, and optic discs or retinas receiving 30 CGEs affected the final VA.

Influence of Ranibizumab versus laser photocoagulation on radiation retinopathy (RadiRet) - a prospective randomized controlled trial

Purpose

To demonstrate superiority of intravitreal ranibizumab 0.5 mg compared to focal and peripheral laser treatment in patients with radiation retinopathy for choroidal melanoma.

Methods

Inclusion criteria were as follows: patients with radiation retinopathy and visual acuity impairment due to radiation maculopathy accessible for laser therapy, age ≥ 18 years, and BCVA less than 20/32. The main objective was to study the change in best-corrected visual acuity (BCVA) over 6 months from ranibizumab 0.5 mg (experimental) compared to focal laser of the macula and panretinal laser treatment of the ischemic retina (control) in patients with radiation retinopathy in choroidal melanoma. The secondary objectives of the radiation retinopathy study were to compare functional and anatomical results between ranibizumab and laser group over 12 months and to measure the frequency of vitreous hemorrhage and rubeosis iridis.

Results

The intention-to-treat analysis included 31 patients assigned to ranibizumab (n = 15) or laser treatment (n = 16). In terms of BCVA at month 6, ranibizumab was superior to laser treatment, with an advantage of 0.14 logMAR, 95% CI 0.01 to 0.25, p = 0.030. The positive effect of ranibizumab disappeared after treatment was discontinued. Similar results without statistically significant difference were found with respect to macular thickness. In both groups, no change was observed at month 6 in the size of ischemia in the macula or periphery compared to baseline. There was 1 case of vitreous hemorrhage in the laser group and no case of rubeosis iridis over time.

Conclusions

This study showed a statistically significant improvement in visual acuity and clear superiority of ranibizumab compared to laser treatment up to 26 weeks, but this effect disappeared at week 52 after completion of intravitreal treatment. Ranibizumab and PRP are considered equivalent in terms of the non-appearance of proliferative radiation retinopathy during the study.

Trial registration

EudraCT Number: 2011-004463-69

Electronic supplementary material

The online version of this article (10.1007/s00417-020-04618-7) contains supplementary material, which is available to authorized users.

Radiation-Induced Optic Neuropathy: Observation versus Intravitreal Treatment: Can Visual Acuity Be Maintained by Intravitreal Treatment?

PURPOSE

To compare intravitreal therapy with the natural course of radiation optic neuropathy after primary proton beam therapy for choroidal melanoma with respect to long-term visual acuity and development of optic atrophy.

DESIGN

Retrospective comparative case series.

METHODS

Inclusion criteria: patients treated with primary proton beam therapy for choroidal melanoma with a minimum follow-up of 24 months after the occurrence of radiation optic neuropathy and optic disc imaging during follow-up.

EXCLUSION CRITERIA

pathologic condition of the optic disc before irradiation and intravitreal therapy to treat cystoid macular edema not originating from the optic disc.

RESULTS

Of 93 patients, 48 were observed only after radiation optic neuropathy, and 45 were treated with intravitreal therapy (triamcinolone, bevacizumab, and/or dexamethasone). Median follow-up was 55 months (29-187 months); median interval between onset of radiation optic neuropathy and the last patient visit was 34 months (24-125 months). Of 48 observed patients, 41 (85.4%) developed an optic atrophy after a median of 14 months (3-86 months) after radiation optic neuropathy; and of 45 intravitreally treated patients, 34 (75.5%) presented with an optic atrophy after a median of 12.5 months (1-55 months) following optic neuropathy, indicating no statistically significant differences between the groups. Comparing the change in visual acuity from occurrence of optic neuropathy to final visual acuity, no statistically significant differences were found between either group (P = 0.579).

CONCLUSIONS

Patients treated with intravitreal therapy for radiation optic neuropathy showed no statistically significant differences related to visual acuity or optic atrophy development from patients who underwent only observation.

Long-Term Visual Outcomes for Small Uveal Melanoma Staged T1 Treated by Proton Beam Radiotherapy

There is increasing evidence of the survival benefit of treating uveal melanoma in an early stage, however it is important to discuss with the patient the associated risk of visual loss. We investigated visual outcomes for uveal melanomas staged T1 (T1UM) treated by proton beam radiotherapy (PBR) as a function of their distance to fovea-optic disc. This retrospective study included a cohort of 424 patients with T1UM treated with PBR between 1991 and 2010 with at least a 5-year follow-up. Visual acuity (VA) was analyzed for patients with posterior edge of tumor located at ≥3 mm (GSup3) or <3 mm (GInf3) from fovea-optic disc. The mean follow-up duration was 122 months, no tumor recurrence was observed. The mean baseline and final VA were 20/25 and 20/32 for GSup3 (n = 75), and 20/40 and 20/80 for GInf3 (n = 317) respectively. The frequency of a 20/200 or greater visual conservation was 93.2%(CI95%:87.7-99.1) and 60.1%(CI95%:54.9-65.9) for GSup3 and GInf3 respectively. This difference between groups was statistically significant (p < 0.001). The risk factors for significant VA loss (less than 20/200) were GInf3 location (p < 0.001), tumor touching optic disc (p = 0.04), initial VA inferior to 20/40 (p < 0.001), documented growth (p = 0.002), and age greater than 60 years (p < 0.001). In summary, PBR for T1UM yields excellent tumor control and good long-term visual outcomes for tumors located ≥3 mm from fovea-optic disc.

Radiation tolerance of the optic pathway in patients treated with proton and photon radiotherapy

INTRODUCTION

Radiation-induced optic neuropathy (RION) is a complication of radiation therapy (RT) that causes blindness. We aimed to define the tolerance of the anterior optic pathway to fractionated RT and identify risk factors for RION.

MATERIALS/METHODS

Patients with chordoma or chondrosarcoma of the skull base treated with proton and photon therapy between 1983 and 2013, who received a minimum of 30 Gy (relative biologic effectiveness [RBE]) to the anterior optic pathway were assessed. Optic neuropathy with radiographic correlation occurring ≥6 months after completion of RT in the absence of tumor recurrence or other probable cause was diagnosed as RION.

RESULTS

Of 514 patients, 17 developed RION. With median follow-up of 4.8 years, cumulative incidence of RION was 1% among patients receiving <59 Gy (RBE) and 5.8% among patients receiving ≥60 Gy (RBE) to the optic pathway. Higher maximum point dose to the optic pathway (subhazard ratio [SHR] = 1.2, 95% CI 1.05-1.2, p = 0.001), older age (SHR = 1.1, 95% CI 1.02-1.08, p < 0.0005), and female sex (SHR = 16.3, 95% CI 2.2-122.4, p = 0.007) were statistically significant risk factors for RION in multivariate analysis.

CONCLUSION

In our study cohort, rates of RION were very low with conventionally fractionated RT up to 59 Gy. At doses ≥60 Gy, there is an increased risk of RION, with greater risk for women and older patients.

Quantification of radiation retinopathy after beam proton irradiation in centrally located choroidal melanoma

PURPOSE

To localize and quantify ischemic changes induced by proton beam irradiation of central choroidal melanoma and to identify baseline predictors correlated with the extent of ischemic changes.

METHODS

Retrospective chart review of patients with central choroidal melanoma treated by proton beam irradiation and conducted widefield fluorescein angiography (≥ 20 months after radiation therapy). Quantification and location of ischemic areas and correlation to baseline predictors. Multiple linear regression model was performed for analyses.

RESULTS

Twenty-five eyes from 25 patients were included in final analysis. Mean largest basal tumor area was 56.6 ± 40.0 mm² and mean maximal tumor prominence 2.5 ± 1.4 mm. Mean total radiated area was 339.1 ± 68.3 mm². All patients showed ischemic changes. Mean ischemic area was 387.6 ± 123.3 mm² and mean ischemic index (ischemic area/total visible area) was 0.53 ± 0.23. Twenty-two patients (88%) presented ischemic changes outside of the irradiation field, which comprised of 23% of total ischemic area. Mean angular distance between lateral border of irradiation field and ischemic area outside of the radiated area was 44.8 ± 36.5°. Multivariable analysis revealed a positive correlation of total ischemic area with total radiated area (p = 0.02) and initial sonographic tumor prominence (p = 0.02).

CONCLUSIONS

Ischemic changes induced by proton beam irradiation of central choroidal melanoma were localized and quantified. Ischemic changes exceed the tumor area distinctly and are found also outside of the irradiation field in the majority of patients. Size of irradiation area and tumor prominence are positively correlated with extent of ischemic area.

Quantitative OCT Angiography Evaluation of Peripapillary Retinal Circulation after Plaque Brachytherapy

OBJECTIVE

To study peripapillary retinal capillary circulation in eyes treated with I-125 plaque brachytherapy for uveal melanoma using optical coherence tomography angiography (OCTA).

DESIGN

Cross-sectional study of 10 subjects imaged with OCTA prior to uveal melanoma treatment and 15 subjects imaged after development of radiation retinopathy and/or optic neuropathy.

PARTICIPANTS

Following IRB approval, subjects were enrolled from an academic ocular oncology clinical practice. All subjects had uveal melanoma in one eye and treatment with I-125 plaque brachytherapy was planned or had previously taken place. Patients with low vision at baseline and uncontrolled hypertension were excluded. In the post-treatment group, seven subjects were male and eight were female; age range 38 to 81 years. Visual acuities in the irradiated eyes ranged from 20/20 to counting fingers. Visual acuities in the untreated fellow eyes were 20/25 or better.

METHODS

Peripapillary retinal capillary circulation was measured by OCTA (Optovue, Inc). 4.5×4.5 mm optic disc scans were obtained. 10 subjects were imaged prior to brachytherapy treatment and 15 subjects were imaged after development of clinically apparent radiation retinopathy and/or radiation optic neuropathy post-brachytherapy.

MAIN OUTCOME MEASURES

The relationship of the peripapillary retinal capillary density (PPCD) as measured by OCTA to the calculated dose to the optic nerve (D50, the dose to 50% of the disc) and the LogMAR vision was evaluated.

RESULTS

No significant difference was seen in the PPCD as measured by OCTA when comparing the eye with melanoma to the fellow eye prior to brachytherapy; however the PPCD was significantly lower in treated eyes (52.9% +/- 22.4%) than in fellow eyes that did not receive radiation (73.3% +/- 13.7%, p = 0.004). There was an inverse linear correlation between D50 and the PPCD (Pearson's; r= -0.528, P=0.043) and between visual acuity and the PPCD (Pearson's; r= -0.564, P=0.028).

CONCLUSIONS

Among patients with clinically apparent radiation retinopathy and/or radiation optic neuropathy, PPCD was lower in the treated eye and correlated with the radiation dose to the optic nerve and the visual acuity. OCTA provides a measure of capillary changes following radiation, and may serve as a quantitative endpoint to address visual prognosis.

Peripapillary vascular changes in radiation optic neuropathy: an optical coherence tomography angiography grading

AIMS

To investigate peripapillary vascular changes secondary to radiation optic neuropathy (RON) using optical coherence tomography angiography (OCT-A) and to propose a clinical grading of RON based on OCT-A findings.

METHODS

Thirty-four patients affected by RON were consecutively included. Each patient underwent best corrected visual acuity measurement (ETDRS score) and OCT-A (Nidek RS-3000 Advance device, Nidek, Gamagori, Japan). The radial peripapillary capillary plexus (RPCP) and the entire peripapillary capillary bed (EPCB) were analysed. Quantitative analysis of the OCT-A images was performed using open-source available ImageJ software (National Institutes of Health, Bethesda, Maryland, USA). Qualitative analysis based on the proposed clinical grading (Grades 0-4) was also performed by two masked graders.

RESULTS

RON clinical (qualitative) classification based on RPCP correlated with the quantitative RPCP perfusion analysis (P=0.0001). RON clinical classification based on RPCP statistically correlated with ETDRS score (P=0.001). RON clinical classification based on EPCB also correlated with the quantitative EPCB perfusion analysis and ETDRS score (P=0.02 and P=0.01, respectively). Compared with the clinical classification based on EPCB, the qualitative classification based on RPCP reached a higher intergrader agreement (0.96 and 0.86, respectively).

CONCLUSION

OCT-A can be used to detect RPCP abnormalities and to clinically classify RON with a high interexaminer agreement. The proposed clinical classification is supported by the quantitative analysis based on the use of specific images elaboration techniques and correlates with visual acuity of the examined eyes.

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.