A randomized controlled trial of varying radiation doses in the treatment of choroidal melanoma

Favorable Outcomes of Patients With High-Risk Uveal Melanoma Treated With a Novel Linear Accelerator-Based Frameless Fractionated Stereotactic Radiosurgery

PURPOSE

Uveal melanoma (UM) represents the most prevalent and aggressive intraocular malignancy in adults. This study examined the outcomes of patients diagnosed with high-risk UM who underwent fractionated stereotactic radiosurgery (fSRS) treatment utilizing a novel Linear Accelerator (LINAC)-based frameless technique.

DESIGN

Retrospective, interventional case series.

METHODS

All patients received fSRS, 50 Gy in 10 Gy/fraction, every other day on a stereotactic LINAC with a novel in-house eye localization and monitoring system. Tumor control, vision outcome, as well as acute and late toxicities were evaluated.

RESULTS

This study included 23 patients with high-risk UM. Median age was 64.8 years old (range 37.9-85.1 years). The Median Karnofsky Performance Score was 90 (range 70-100). The median tumor diameter was 13.5 mm (range 3.0-24.0 mm), and median tumor thickness was 5.05 mm (range 1.2-15.1 mm). There were 11 patients (47.8%) who received prior episcleral plaque. The other 12 patients received stereotactic radiotherapy for initial treatment. With a median follow-up of 38 months, the local control rate was 95.6% at 1 year, 90.1% at 2 years, and 85.6% at 3 years. There was no significant difference between treatment-naïve patients and those who had previously received plaque treatment. Eye preservation rate was 91.3%, with 2 patients required enucleation for tumor progression and/or toxicity. High-grade acute adverse events included 1 patient with grade 3 eye pain. The median best-corrected visual acuity by LogMAR was 0.5 pretreatment (Snellen conversion 20/63) and 1.0 (Snellen 20/200) post-treatment.

CONCLUSIONS

Our institution's novel LINAC-based frameless fSRS demonstrated favorable local control and toxicity profile for high-risk UM (tumors deemed unsuitable for episcleral plaque brachytherapy). Patients maintained a high rate of eye preservation. This approach provides an eye preservation option for patients unable to have plaque radiotherapy.

Proton Therapy in Uveal Melanoma

Background/Objectives: Uveal melanoma is the most common primary intraocular malignancy in adults. Treatment options for localized, early-stage disease include enucleation, brachytherapy, and proton beam therapy. This review aims to evaluate the role of proton therapy in the definitive management of uveal melanoma, focusing on its physics, radiobiology, treatment techniques, and associated outcomes. Methods: This narrative review synthesizes current literature on proton therapy for uveal melanoma, emphasizing case selection, treatment efficacy, and side effects. Results: Proton therapy offers significant advantages for thicker uveal melanomas (over 8 mm) due to its unique physical properties, including a rapid dose fall-off that protects critical structures like the retina and optic nerve. Proton therapy may have benefits in tumor control for ocular melanomas given its increased relative biological effectiveness relative to photon therapy for these typically more radioresistant melanomas. Proton therapy may also hold special value for uveal melanomas in close proximity to the optic nerve, as patients are at high risk of visual toxicities with brachytherapy. The review discusses the efficacy of proton therapy across small, medium, and large tumors, along with strategies for improving patient survival through combined systemic therapy. Additionally, the potential of ocular reirradiation with proton therapy is addressed. Conclusions: Proton therapy is an effective treatment for uveal melanoma. It offers advantages over brachytherapy for large tumors, tumors that are close to the optic nerve or insertion of extra-ocular muscles.

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.

Is It Possible to Preserve Vision without Compromising Metastases-Free Survival by Use of Fully Fractionated Stereotactic Radiotherapy for Posterior Choroidal Melanoma?

Introduction

Stereotactic radiotherapy (SRT) is used for choroidal melanoma (CM) abutting the optic nerve. Visual acuity (VA) deterioration to ≤6/60 is common. We report a pilot study of reduced-dose SRT using 2 Gy/day, aiming to preserve vision without compromising survival.

Method

60 Gy SRT was delivered in 30 fractions over 6 weeks. Liver metastasis surveillance was annual ultrasound. The primary endpoint was 5-year metastasis-free survival (5yMFS). Secondary endpoints were 2-year freedom from local progression (2yFFLP), VA, enucleation rate, and radiation toxicity.

Results

Twenty adults aged ≤70 years with T1-T2M0 CM without diabetes mellitus were enrolled. Median follow-up was 5.1 years. About 85% and 90% of tumours were ≤3 mm of the macula and optic disc, respectively. Median tumour height was 2.2 mm (range 1.0-4.4 mm), and median basal diameter was 8.2 mm (range: 4.3-15.0 mm). 5yMFS was 88% (95% CI: 61-97), and the 2yFFLP rate was 90% (95%: CI 66-97). There were three enucleations for disease progression. Final VA in retained eyes was ≥6/7.5 in 6 (30%), 6/9 to 6/12 in 5 (25%), 6/15 to 6/48 in 2 (10%), and ≤6/60 in 4 (20%) eyes. Retinopathy was the main cause of vision loss besides tumour progression.

Conclusion

Meaningful vision was preserved 5 years after SRT, despite high-risk tumour locations for vision loss. 2yFFLP and 5yMFS were acceptable. This dose fractionation warrants further investigation.

Visual outcomes of macular melanocytic lesions after early or delayed proton beam therapy

PURPOSE

During their initial management, some macular melanocytic lesions can be closely monitored to wait for a documented growth before advocating a treatment by irradiation. However, the visual outcomes of this strategy have not yet been assessed. This study compares the visual outcomes of macular melanocytic lesions that underwent delayed proton beam therapy (PBT) after an initial observation to those treated early.

METHODS

A total of 162 patients with suspicious melanocytic lesions whose margins were located within 3 mm of the fovea were recruited from two French ocular oncology centers.

RESULTS

Overall, 82 patients treated with PBT within 4 months after the initial visit (early PBT group) were compared to 24 patients treated with delayed PBT (delayed PBT group) and 56 patients not treated with PBT (observation group). Visual acuity was not significantly different between baseline and last visit in the observation group (p = 0.325). Between baseline and last visit, the median [IQR] loss in visual acuity was significant in both the early (0.7 [0.2; 1.8], p < 0.001) and the delayed (0.5 [0.2; 1.5], p < 0.001) PBT groups. After irradiation, there was no significant difference between the early and delayed PBT groups for visual loss (p = 0.575), diameter reduction (p = 0.190), and thickness lowering (p = 0.892). In multivariate analysis, history of diabetes mellitus and Bruch's membrane rupture remained significantly associated with greater visual loss (p = 0.036 and p = 0.002, respectively).

CONCLUSION

For small lesions in which there is no clear diagnosis of malignant melanoma, an initial close monitoring to document tumor growth does not impact visual prognosis, despite the potential complications associated with the untreated tumor. However, the survival should remain the main outcome of the treatment of these lesions.

A Comparison of Treatment Outcomes after Standard Dose (70 Gy) versus Reduced Dose (50 Gy) Proton Radiation in Patients with Uveal Melanoma

OBJECTIVE

To compare outcomes in a large patient cohort with small-medium tumors located within 1 disc diameter (DD) of the optic nerve and/or fovea treated with 50 Gy or 70 Gy proton therapy.

DESIGN

Retrospective cohort study.

SUBJECTS

A total of 1120 patients with uveal melanomas ≤ 15 mm in largest basal diameter, ≤ 5 mm in height, located within 1 DD of the optic nerve and/or fovea, who received primary treatment with protons between 1975 and 2016 at Massachusetts Eye and Ear/Massachusetts General Hospital.

METHODS

The rates of outcomes were estimated using the Kaplan-Meier method. Differences between the radiation dose groups were tested using the log-rank test.

MAIN OUTCOME MEASURES

Local tumor recurrence, melanoma-related mortality, and visual acuity preservation (≥ 20/200, ≥ 20/40).

RESULTS

Local tumor recurrence was observed in 1.8% of the 50 Gy group and 1.5% of the 70 Gy group. The median time to recurrence was 30.7 months for patients treated with 50 Gy and 32.0 months for those treated with 70 Gy (P = 0.28). Five-year rates of vision retention (≥20/40, ≥ 20/200) were 19.4% and 49.3% for patients treated with 50 Gy and 16.4% and 40.7% in those treated with 70 Gy. Ten-year rates of melanoma-related mortality were 8.4% in the 50 Gy group and 8.9% in the 70 Gy group (P = 0.47).

CONCLUSIONS

Comparable rates of local control are achieved treating small-medium tumors near the optic nerve and/or fovea with 50 Gy or 70 Gy proton therapy, supporting the use of the lower dose in patients with these tumor characteristics.

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.

Preliminary Results of Uveal Melanoma Treated With Iodine-125 Plaques: Analysis of Disease Control and Visual Outcomes With 63 Gy to the Target Volume

Purpose

Our purpose was to review the preliminary outcomes of patients with uveal melanoma treated with iodine-125 plaques using a novel treatment planning approach.

Methods and Materials

This was a single institution, retrospective review of patients treated with iodine-125 brachytherapy for uveal melanoma from November 2016 to February 2019. We used 3-dimensional treatment planning with the Eye Physics Plaque Simulator to ensure that a minimum of 63 Gy covered a 2-mm circumferential tumor margin and the apex height of the tumor over 94 hours. Primary endpoints were local failure, systemic metastasis, final visual acuity (VA), and radiation retinopathy. Associations between primary endpoints and tumor characteristics/radiation dose were performed using univariate analysis.

Results

Sixty-nine patients were included in the analysis. Mean largest basal diameter was 11.67 mm (range, 6-18; median, 12), and the average tumor thickness to the inner sclera was 3.18 mm (range, 0.5-9.3; median, 2.8). Molecular testing that was successfully performed in 59 patients revealed that 27% (16 of 59) had class 2 gene expression profile designation. Average follow-up posttreatment was 28.3 months (range, 4-46; median, 29), with 6% (4 of 69) developing local failure and 6% (4 of 69) developing metastasis over this duration. Average final VA (0.57 logMAR [Snellen 20/74]; range, 0-2.9; median, 0.3) was decreased from baseline (0.34 logMAR [Snellen 20/44]; range, 0-2.3; median, 0.1), and 48% (33 of 69) developed radiation retinopathy. Fifty percent of patients had a final VA 20/40 or better and 22% had a final VA 20/200 or worse.

Conclusions

In patients with uveal melanoma, preliminary results with brachytherapy using Eye Physics plaques with a treatment plan that delivers 63 Gy to a 2-mm circumferential tumor margin and the tumor apex suggest effective disease control and favorable VA outcomes.

Treatment of Uveal Melanoma With Radioactive Iodine 125 Implant Compared With Proton Beam Radiotherapy

Objective

To review the current state of radiation therapy for uveal melanoma and compare particle radiation and brachytherapy.

Patients and Methods

The medical records of 156 patients treated for uveal melanoma between May 30, 2012, and March 16, 2020, were retrospectively reviewed. Treatments consisted of either radioactive iodine 125 implant (RAI) or fractionated proton radiation (proton beam therapy [PBT]). Baseline characteristics were compared using a Wilcoxon rank sum test or χ² test. Outcomes were compared using Cox proportional hazards regression models or logistic regression models.

Results

The median length of follow-up after treatment was 2.7 years (range, 0.5 to 9.0 years). Patients who underwent treatment with RAI were older (median age, 67 vs 59 years; P<.001) and had a lower tumor classification (American Joint Commission on Cancer; P=.001) compared with those who underwent PBT. There was no significant difference between RAI and PBT in the outcomes of liver metastases, death, enucleation, tearing, vision loss, retinal detachment, tumor thickness, conjunctivitis, optic neuropathy, iris neovascularization, or neovascular glaucoma (all P>.05). Patients who underwent RAI treatment had significantly higher risk of diplopia (P<.001), cataract progression (P<.001), and maculopathy (P=.03) compared with those who received PBT. Patients who underwent RAI were at higher risk of eyelash loss (P=.006) compared with the PBT group.

Conclusion

Treatment with PBT and RAI has similar efficacy; however, there are differences in the adverse outcomes associated with these 2 modalities.

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.

Current status and application of proton therapy for esophageal cancer

Esophageal cancer remains one of the leading causes of death from cancer across the world despite advances in multimodality therapy. Although early-stage disease can often be treated surgically, the current state of the art for locally advanced disease is concurrent chemoradiation, followed by surgery whenever possible. The uniform midline tumor location puts a strong importance on the need for precise delivery of radiation that would minimize dose to the heart and lungs, and the biophysical properties of proton beam makes this modality potential ideal for esophageal cancer treatment. This review covers the current state of knowledge of proton therapy for esophageal cancer, focusing on published retrospective single- and multi-institutional clinical studies, and emerging data from prospective clinical trials, that support the benefit of protons vs photon-based radiation in reducing postoperative complications, cardiac toxicity, and severe radiation induced immune suppression, which may improve survival outcomes for patients. In addition, we discuss the incorporation of immunotherapy to the curative management of esophageal cancers in the not-too-distant future. However, there is still a lack of high-level evidence to support proton therapy in the treatment of esophageal cancer, and proton therapy has its limitations in clinical application. It is expected to see the results of future large-scale randomized clinical trials and the continuous improvement of proton radiotherapy technology.

Uveal Melanoma - Standardised Procedure in Diagnosis, Therapy and Surveillance

BACKGROUND

Uveal melanoma is a rare intraocular tumour, for which there is currently no national evidence-based guideline in Germany. The aim of this project was to provide a common standard operating procedure (SOP) for the diagnosis, treatment and follow-up care of uveal melanoma, within the network of German leading oncology centres funded by German Cancer Aid. The SOP was created as part of a moderated consensus process.

RESULTS AND CONCLUSION

In a multistage process, a common SOP was developed for the diagnosis, therapy and follow-up of uveal melanoma, as based on current knowledge of the subject.

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.

Proton Beam Therapy in the Treatment of Periorbital Malignancies

Purpose

Periorbital tumor location presents a significant challenge with 3-dimensional conformal radiation therapy or intensity modulated radiation therapy due to high tumor dose needed in the setting of close proximity to orbital structures with lower tolerance. Proton beam therapy (PBT) is felt to be an effective modality in such cases due to its sharp dose gradient.

Materials and Methods

We reviewed our institutional PBT registry and identified 17 patients with tumor epicenters within 2 cm of the eye and optic apparatus treated with passive scatter PBT with comparison volumetric arc therapy plans available. Maximum and mean doses to organs at risk of interest, including optic nerves, optic chiasm, lens, eye ball, pituitary, cochlea, lacrimal gland, and surrounding brain, were compared using the paired Wilcoxon signed rank test. Overall survival was determined using the Kaplan-Meier method.

Results

Median age was 67. Median follow-up was 19.7 months. Fourteen patients underwent upfront resection and received postoperative radiation and 3 received definitive radiation. One patient received elective neck radiation, 2 underwent reirradiation, and 3 had concurrent chemotherapy. There was a statistically significant reduction in mean dose to the optic nerves and chiasm, brain, pituitary gland, lacrimal glands, and cochlea as well as in the maximum dose to the optic nerves and chiasm, pituitary gland, lacrimal glands, and cochlea with PBT. The 18-month cumulative incidence of local failure was 19.1% and 1-year overall survival was 80.9%.

Conclusion

Proton beam therapy resulted in significant dose reductions to several periorbital and optic structures compared with volumetric arc therapy. Proton beam therapy appears to be the optimal radiation modality in such cases to minimize risk of toxicity to periorbital organs at risk.

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.

Gamma knife radiosurgery for uveal melanomas and metastases: a systematic review and meta-analysis

BACKGROUND

Gamma knife radiosurgery is regarded as the gold-standard stereotactic radiosurgery modality for the treatment of intracranial tumours, and its use has been expanded for the treatment of intraocular malignancies. The aim of this study was to systematically evaluate the efficacy, outcomes, and complications of gamma knife radiosurgery for uveal melanomas and metastases.

METHODS

We did a systematic review and meta-analysis to aggregate the clinical outcomes of patients with uveal melanomas or intraocular metastases treated primarily with gamma knife radiosurgery. We searched MEDLINE and Embase for studies published between Sept 1, 1960, and Feb 1, 2020, reporting the use of gamma knife radiosurgery as primary treatment for uveal melanoma or uveal metastases. The search was restricted to clinical studies and relevant grey literature published in English. Studies reporting treatment of benign tumours, extraocular tumours, or other forms of stereotactic radiosurgery were excluded to reduce heterogeneity. No restrictions were placed on participant criteria. Local tumour control and tumour regression were extracted as the primary outcomes and analysed via a random-effects meta-analysis of proportions using the DerSimonian and Laird method with a Freeman-Tukey double arcsine transformation. This study is registered with PROSPERO, CRD42019148165.

FINDINGS

Our search returned 454 studies, of which 109 were assessed for full-text eligibility. 52 studies, reporting on 1010 patients with uveal melanoma and 34 intraocular metastases, were eligible for systematic review. 28 studies were included in the meta-analysis. 840 of 898 patients (0·96, 95% CI 0·94-0·97; I²=16%) from 19 studies had local control, and 378 of 478 patients (0·81, 0·70-0·90; I²=83%) from 16 studies experienced tumour regression.

INTERPRETATION

Gamma knife radiosurgery is an efficacious primary method of treating uveal melanomas and intraocular metastases, with reliable tumour control rates. Randomised controlled trials should further evaluate the safety and efficacy of gamma knife radiosurgery in this setting.

FUNDING

The Rhodes Trust and the Howard Brain Sciences Foundation.

Evolution of Care of Orbital Tumors with Radiation Therapy

Orbital tumors are rare lesions comprising 0.1% of all tumors and less than 20% of all ocular diseases. These lesions in children and adults differ significantly in their incidence, tumor type, and treatment management. Although surgery and systemic therapies are commonly used in the management of these diseases, radiation therapy has become a widely used treatment for both benign and malignant tumors of the orbit. Radiotherapy is used as a definitive treatment to provide local control while avoiding morbidity associated with surgery for some tumors while it is used as an adjuvant treatment following surgical resection for others. For many tumors, radiation provides excellent tumor control with preservation of visual function. This article is dedicated for presenting the most common applications of orbital radiotherapy. A brief overview of the commonly available radiation therapy modalities is given. Dose constraint goals are reviewed and acute and long-term side effects are discussed. Orbital tumors covered in this article include optic glioma, ocular melanoma, retinoblastoma, orbital rhabdomyosarcoma, orbital lymphoma, and lacrimal gland tumors. Background information, indications for radiotherapy, and goals of treatment for each case example are described.

Reirradiation for Recurrent Scalp Angiosarcoma: Dosimetric Advantage of PBT over VMAT and EBT

Purpose

Reirradiation in the scalp area can be challenging given the proximity to organs at risk (OARs), such as the eye and brain. Our aim is to evaluate the dosimetric differences of volumetric modulated arc therapy (VMAT) and electron beam therapy (EBT) compared with 3-dimensional proton beam therapy (PBT).

Patients and Methods

We evaluated a patient with recurrent angiosarcoma of the left temporal scalp after prior surgical resections and radiation therapy to 60 Gy in 30 fractions who needed reirradiation. We generated VMAT, EBT, and PBT plans using the Pinnacle Treatment Planning System (TPS). Both VMAT and EBT plans used a skin bolus, whereas no bolus was used for the proton plan. Doses to the OARs, including cochlea, eyes, lens, lacrimal glands, optic nerves, optic chiasm, pituitary gland, and underlying brain, were compared.

Results

The reirradiation treatment dose was 60 Gy(RBE). Target volume coverage was comparable in all plans. Compared with VMAT and EBT, the PBT plan showed reductions in mean and maximum doses to all OARs. Without the use of protons, several OARs would have exceeded dose tolerance utilizing VMAT or electrons. Dose reduction of up to 100% was achieved for central and contralateral OARs.

Conclusion

Compared with VMAT and EBT, PBT resulted in dose reductions to all OARs, while maintaining excellent target coverage. PBT showed a significant advantage in treating superficially located skin cancers, such as angiosarcoma, without the need for a bolus. PBT can be considered in the upfront treatment and certainly in the reirradiation setting.

Particle therapy tumour outcomes: An updated systematic review

Particle therapy (PT) offers the potential for reduced normal tissue damage as well as escalation of target dose, thereby enhancing the therapeutic ratio in radiation therapy. Reflecting the building momentum of PT use worldwide, construction has recently commenced for The Australian Bragg Centre for Proton Therapy and Research in Adelaide - the first PT centre in Australia. This systematic review aims to update the clinical evidence base for PT, both proton beam and carbon ion therapy. The purpose is to inform clinical decision-making for referral of patients to PT centres in Australia as they become operational and overseas in the interim. Three major databases were searched by two independent researchers, and evidence quality was classified according to the National Health and Medical Research Council evidence hierarchy. One hundred and thirty-six studies were included, two-thirds related to proton beam therapy alone. PT at the very least provides equivalent tumour outcomes compared to photon controls with the possibility of improved control in the case of carbon ion therapy. There is suggestion of reduced morbidities in a range of tumour sites, supporting the predictions from dosimetric modelling and the wide international acceptance of PT for specific indications based on this. Though promising, this needs to be counterbalanced by the overall low quality of evidence found, with 90% of studies of level IV (case series) evidence. Prospective comparative clinical trials, supplemented by database-derived outcome information, preferably conducted within international and national networks, are strongly recommended as PT is introduced into Australasia.

Systematic review of methodology used in clinical studies evaluating the benefits of proton beam therapy

BACKGROUND

Proton beam therapy (PBT) delivers high-energy radiation to target tumours while sparing surrounding normal tissues. The dosimetric advantages of PBT over traditional photon radiotherapy may be clear but the translation of this benefit into clinically meaningful reductions in toxicities and improved quality-of-life (QoL) needs to be determined. Randomised controlled trials (RCTs) are considered the gold standard for generating the highest-level evidence in medicine. The objectives of this systematic review were to provide an overview of published clinical studies evaluating the benefits of PBT, and to examine the methodology used in clinical trials with respect to study design and outcomes.

METHODS

PubMed, EMBASE and Cochrane databases were systematically searched for published clinical studies where PBT was a cancer treatment intervention. All randomised and non-randomised studies, prospective or retrospective, were eligible for inclusion.

RESULTS

In total, 219 studies were included. Prospective studies comprised 89/219 (41%), and of these, the number of randomised phase II and III trials were 5/89 (6%) and 3/89 (3%) respectively. Of all the phase II and III trials, 18/24 (75%) were conducted at a single PBT centre. Over one-third of authors recommended an increase in length of follow up. Research design and/or findings were poorly reported in 74/89 (83%) of prospective studies. Patient reported outcomes were assessed in only 19/89 (21%) of prospective studies.

CONCLUSIONS

Prospective randomised evidence for PBT is limited. The set-up of national PBT services in several countries provides an opportunity to guide the optimal design of prospective studies, including RCTs, to evaluate the benefits of PBT across various disease sites. Collaboration between PBT centres, both nationally and internationally, would increase potential for the generation of practice changing evidence. There is a need to facilitate and guide the collection and analysis of meaningful outcome data, including late toxicities and patient reported QoL.

Corneal Substructure Dosimetry Predicts Corneal Toxicity in Patients With Uveal Melanoma Treated With Proton Beam Therapy

PURPOSE

This study examines the relationship between dose to corneal substructures and incidence of corneal toxicity within 6 months of proton beam therapy (PBT) for uveal melanoma. We aim to develop clinically meaningful dose constraints that can be used to mitigate corneal toxicity.

METHODS AND MATERIALS

Ninety-two patients were treated with PBT between 2015 and 2017 and evaluated for grade 2+ (GR2+) intervention-requiring corneal toxicity in our prospectively maintained database. Most patients were treated with 50 Gy (relative biological effectiveness [RBE]) in 5 fractions, and all had complete six-month follow-up. Analyses included Mann-Whitney, χ², Fisher exact, and receiver operating curve tests to identify risk factors for GR2+ toxicity. Bivariate logistic regression was used to identify independent dose-volume histogram (DVH) predictors of toxicity after adjustment for the most important clinical risk factor.

RESULTS

The 6-month PBT GR2+ corneal toxicity rate was 10.9%, with half of patients experiencing grade 2 toxicity and half experiencing grade 3 toxicity, with no grade 4 events. Patients with anterior chamber tumors had a higher risk (58.3%) for toxicity than those with posterior tumors (0%) or posterior tumors extending past the equator (25%, P < .0001). On univariate analysis, larger size according to Collaborative Ocular Melanoma Studies was associated with increased toxicity rate (P < .004). DVH analysis revealed that cutoffs of 58% for V25, 32% for V45, 51.8 Gy (RBE) for maximum dose, and 32 Gy (RBE) for mean dose to the cornea separated patients into groups experiencing and not experiencing toxicity with 90% sensitivity and ≥96% specificity. Bivariate logistic regression indicated that corneal V25, V45, and mean dose independently predicted for toxicity after adjusting for tumor location.

CONCLUSIONS

Patients receiving PBT for anterior uveal melanomas experience a high rate of GR2+ corneal toxicity because of increased corneal dose. Anterior location and corneal DVH parameters independently predict toxicity risk. We propose dosimetric constraints to facilitate treatment planning and toxicity mitigation.

Dose-response in choroidal melanoma

PURPOSE

In choroidal melanoma the radiation threshold dose for local control remains largely unknown. The present study examined a group of patients that received a wide range of minimum tumor dose in order to investigate a dose-response relationship. A literature review is performed to compare our results with available evidence in brachytherapy and charged particle external beam radiotherapy.

MATERIALS AND METHODS

A retrospective study was conducted on all choroidal melanomas treated with Strontium-90 (Sr-90) at the University Hospital of Leuven between 1983 and 2012. Local failure was defined as primary endpoint and was estimated according to the competing risk method.

RESULTS

In 135 patients, the minimum tumor dose (Dmin) ranged from 0 Gy to 287 Gy (median: 27.6 Gy). Multivariable analysis revealed Dmin ≥ 65 Gy (p = 0.04; HR = 0.09) and tumor distant from the optic disc (p < 0.001, HR = 0.09) to be independent variables favoring local control. The scleral dose, the tumor diameter and tumor height did not significantly affect local failure in multivariate analysis.

CONCLUSION

This is the first study to examine a group of patients treated with a Dmin ranging from 0 Gy to >250 Gy. Treatment with a Dmin of 65 Gy is necessary to achieve durable tumor response. The dose-response data provided by our study could be used for the design of future trials examining the ideal dose for the treatment of choroidal melanoma with brachytherapy or charged particle external beam radiotherapy.

Clinical Application of Proton Beams in the Treatment of Uveal Melanoma: The First Therapies Carried Out in Italy and Preliminary Results (Catana Project)

Background

The first Italian proton therapy facility was realized in Catania, at the INFN-LNS. With its energy (62 MeV proton beam), it is ideal for the treatment of shallow tumors like those of the ocular region: uveal melanoma, first of all (the most common primary intraocular malignancy of adults) and other less frequent lesions like choroidal hemangioma, conjunctiva melanoma, and eyelid tumors.

Material and methods

The first patient was enrolled in February 2002, and to date 30 patients have been treated. All patients had a localized uveal melanoma, with no systemic metastases, and had specific indications for proton beam radiation therapy: lesions between 5–25 mm basal diameter, not exceeding 15 mm thickness, absence of total retinal detachment or glaucoma. According to the tumor dimensions, 2 patients had a small lesion or T1 (6%), 3 had a medium-sized lesion or T2 (10%), 14 had a large lesion or T3 (47%), and 11 had an extra-large lesion or T3 (37%); no patient had extrascleral invasion or T4 of the TNM-AJCC Staging System. In most cases, the tumor infiltrated only the choroid (14 patients, 47%) or the choroid plus the ciliary body (14 patients, 47%). We also treated a primitive iris melanoma, without diffusion to the ciliary body. The target volume was defined as the tumor plus a safety margin of 2.5 mm, laterally and antero-posteriorly; this margin was increased to 3 mm if ciliary body involvement was present. The treatment was carried out in 4 fractions on 4 consecutive days to a total dose of 54.5 Gy (single fraction 13.6 Gy), which corresponds to 60 CGE (Cobalt Gray Equivalent; single fraction 15 CGE), because the relative biological effectiveness is 1.1.

Results

The first follow-up is planned at 6–8 months after the end of the treatment, and our clinical end points are local control (defined as cessation of growth or tumor shrinkage), eye retention, and maintenance of a good visual function. At the time of this writing, we had preliminary results from 13 patients. Nine patients showed tumor shrinkage (69%), 3 a substantially stable dimension (23%), but almost all patients presented an increased ultrasound reflectivity (a surrogate for tumor control).

Discussion and conclusions

The literature data show that charged particle therapy has allowed an optimal local control in the treatment of uveal melanomas (about 96% in the different series, superior to that obtained with plaquetherapy [between 83% and 92%]), a metastatic rate slightly better than enucleation reports, and a survival rate of almost 90% at 5 years. Our preliminary results show a tumor response in almost all cases, with no major acute or subacute side effects. We thus plan to continue with our treatment procedures and our dose prescription.

Nonsurgical Treatment of an Incompletely Excised Primary Adenocarcinoma of Nonpigmented Ciliary Epithelium

Primary adenocarcinoma of the nonpigmented ciliary epithelium (NPCE) is a very rare disease and the majority of acquired cases were treated by enucleation. We report the case of a 19-year-old man who had an adenocarcinoma arising from the NPCE. The tumor was found incidentally due to changed pupil shape. An excisional biopsy was performed and histopathological examination showed primary adenocarcinoma of the NPCE with a positive resection margin. Because of the positive resection margin and to save the eye, radiotherapy rather than enucleation was performed, followed by chemotherapy. Two years after the diagnosis, the patient continues to be followed up without evidence of relapse or cataract change.

Our case suggests that adjunctive radiotherapy should be considered as a sight-saving treatment modality for primary malignant tumors of the NPCE.

Ruthenium brachytherapy for uveal melanomas: Factors affecting the development of radiation complications

PURPOSE

To investigate how treatment complications are related to dosimetric parameters after ruthenium-106 brachytherapy for uveal melanoma, in a large, clinically homogeneous population.

METHODS AND MATERIALS

A retrospective review was performed to evaluate patients affected by small and medium size uveal melanoma, treated with ruthenium-106 brachytherapy from December 2006 to December 2014. We excluded tumors with posterior margin within 1 mm from the edge of the optic disc and foveola. Main outcome measures were occurrence and time to radiation-related maculopathy, cataract, and optic neuropathy. Secondary end points included local recurrence and distant metastases. Kaplan-Meier analysis with log-rank test and univariate Cox proportional hazards model at 3 years were performed to identify the covariates affecting the outcome of radiation complications.

RESULTS

Two hundred thirty-nine patients, with sufficient data to evaluate the end points, were enrolled. Three years after plaque treatment, radiation maculopathy was found in 61 (25.5%) patients, cataract developed in 10 patients (4.2%) receiving a dose of 27 Gy or higher to the lens, and optic neuropathy was observed in 13 patients (5.4%) with an optic nerve dose exceeding 50 Gy and tumor proximity to optic disc of less than 4 mm. Tumor recurrences and tumor-related metastasis were found respectively in 20 (8.36%) and 14 (5.85%) patients.

CONCLUSIONS

Radiation maculopathy occurs within a median time of 31 months in 25% of cases after plaque treatment for uveal melanoma. The most significant risk factors are total dose and distance of tumor margin from the fovea. If the distance is greater than 11.22 mm, no signs of retinal damage are detected.

Patterns of care and outcomes of proton and eye plaque brachytherapy for uveal melanoma: Review of the National Cancer Database

PURPOSE

To examine national practice patterns and outcomes of eye plaque brachytherapy compared to proton external beam radiotherapy in the treatment of choroid melanoma.

METHODS AND MATERIALS

Demographic and clinical data for 1224 patients with choroid melanoma treated with either brachytherapy or proton beam therapy from 2004 to 2013 were obtained from the National Cancer Database. Logistic regression and propensity score matching was used to create a 1:1 matched cohort. Kaplan-Meier and Cox regression analyses were performed to evaluate survival in brachytherapy and proton groups.

RESULTS

Median followup was 37 and 29 months for brachytherapy and protons, respectively. Most patients were treated with brachytherapy (n = 996) vs. protons (n = 228). Proton patients came from more urban, affluent, and educated zip codes, and they were more likely to be treated at an academic center (all p < 0.004). In the propensity-score matched cohort, 2-year overall survival was 97% vs. 93%, and 5-year overall survival was 77% vs. 51% for brachytherapy and protons, respectively (p = 0.008). Multivariate Cox regression found older age (hazard ratio [HR] = 1.06, 95% confidence interval (CI) = 1.03-1.09), larger tumor diameter (12-18 mm, HR = 2.48, 95% CI = 1.40-4.42, >18 mm, HR = 6.41, 95% CI = 1.45-28.35), and protons (HR = 1.89, 95% CI = 1.06-3.37) were negative prognosticators of survival.

CONCLUSIONS

Patients selected for proton treatment have inferior survival outcomes compared to brachytherapy in this retrospective analysis. There may be unaccounted variables that influence survival, warranting further prospective studies.

Low-dose brachytherapy strategies to treat uveal melanoma: is less more?

The Collaborative Ocular Melanoma Study (COMS) has established equivalency of globe salvaging brachytherapy compared with enucleation in terms of survival for medium-sized choroidal melanoma. The radiation dose protocol followed by the COMS was 85 Gray to a prescription point of the tumor apex or 5 mm inner sclera; whichever was greater. While the COMS realized appropriate local and distant tumor control rates, ocular morbidity due to radiation complications remains a significant clinical challenge. Recent studies challenge the COMS radiation dose paradigm by demonstrating similar tumor control by utilizing lower radiation doses that are associated with reduced radiation toxicity. Improved operative techniques including intraoperative ultrasound can aid to obtain adequate radiation delivery to the tumor by ensuring optimal plaque position. Adjuvant transpupillary thermotherapy, intravitreal anti-VEGF and posterior sub-Tenon steroids may further enhance outcome by providing additional tumor control and/or facilitating visual recovery.

Role of radiation therapy in melanomas: Systematic review and best practice in 2016

Radiotherapy has been used for skin cancers since early after the discovery of X-rays. The introduction of sophisticated surgery techniques and information of the general population on potential late radiation-induced toxicity and carcinogenesis have led to limiting indications in the dermatologist community. However, radiotherapy (RT) has undergone considerable developments, essentially including technological advances, to sculpt radiation delivery, with demonstration of the benefit either alone or after adding concomitant cytotoxic agents or targeted therapies. Although side effects due to high doses and/or the use of old RT techniques have been significantly decreased, the risk of atrophic scars, ulcerations or secondary cancers persist. In this systematic review, we aim to discuss indications for RT in melanomas with focus on new advances that may lead to rehabilitating this treatment option according to the tumor radiosensitivity and clinical benefit/risk ratio. Melanomas have been considered as radioresistant tumors for many years.

Role for radiation therapy in melanoma

Although melanoma is generally considered a relative radioresistant tumor, radiation therapy (RT) remains a valid and effective treatment option in definitive, adjuvant, and palliative settings. Definitive RT is generally only used in inoperable patients. Despite a high-quality clinical trial showing adjuvant RT following lymphadenectomy in node-positive melanoma patients prevents local and regional recurrence, the role of adjuvant RT in the treatment of melanoma remains controversial and is underused. RT is highly effective in providing symptom palliation for metastatic melanoma. RT combined with new systemic options, such as immunotherapy, holds promise and is being actively evaluated.

Proton beam radiotherapy of diffuse iris melanoma in 54 patients

BACKGROUND

Treatment modalities in iris melanoma include excision, plaque radiotherapy, photon or proton beam therapy and enucleation. In extensive tumours and diffuse seeding, radiotherapy remains as an alternative to enucleation.

METHODS

This study is a retrospective, consecutive, interventional, single-institutional case series. 54 patients with a diffuse and non-resectable iris melanoma diagnosed from September 1998 to June 2012 were included. A 68-megaelectron volt proton beam was used to treat the anterior segment with a total dose of 4×12.5 cobalt grey equivalent. The cases were evaluated for local tumour control, eye retention, functional outcome and local complications after treatment.

RESULTS

During a mean follow-up of 62.7 months (median 54.8 months, range 5.5-159.6 months), local tumour control was achieved in 96.3% of the patients. Cataract and glaucoma were the main complications developing after irradiation in 42.6% and 55.6%, respectively. In 34 of 44 patients (77.3%) who underwent cataract removal, a visual acuity of 20/40 or better following surgery was preserved. Enucleation was performed in three patients. The reason was suspected tumour recurrence in one and glaucoma in two. Hepatic metastasis occurred in one patient.

CONCLUSIONS

As an alternative to enucleation, whole anterior segment fractionated proton beam radiotherapy offered excellent local tumour control in diffuse iris melanoma. Given the limited alternatives, the rate of complications appears acceptable and visual function could be preserved in the majority of the patients during follow-up.

Recommendations for the referral of patients for proton-beam therapy, an Alberta Health Services report: a model for Canada?

BACKGROUND

Compared with photon therapy, proton-beam therapy (pbt) offers compelling advantages in physical dose distribution. Worldwide, gantry-based proton facilities are increasing in number, but no such facilities exist in Canada. To access pbt, Canadian patients must travel abroad for treatment at high cost. In the face of limited access, this report seeks to provide recommendations for the selection of patients most likely to benefit from pbt and suggests an out-of-country referral process.

METHODS

The medline, embase, PubMed, and Cochrane databases were systematically searched for studies published between January 1990 and May 2014 that evaluated clinical outcomes after pbt. A draft report developed through a review of evidence was externally reviewed and then approved by the Alberta Health Services Cancer Care Proton Therapy Guidelines steering committee.

RESULTS

Proton therapy is often used to treat tumours close to radiosensitive tissues and to treat children at risk of developing significant late effects of radiation therapy (rt). In uncontrolled and retrospective studies, local control rates with pbt appear similar to, or in some cases higher than, photon rt. Randomized trials comparing equivalent doses of pbt and photon rt are not available.

SUMMARY

Referral for pbt is recommended for patients who are being treated with curative intent and with an expectation for long-term survival, and who are able and willing to travel abroad to a proton facility. Commonly accepted indications for referral include chordoma and chondrosarcoma, intraocular melanoma, and solid tumours in children and adolescents who have the greatest risk for long-term sequelae. Current data do not provide sufficient evidence to recommend routine referral of patients with most head-and-neck, breast, lung, gastrointestinal tract, and pelvic cancers, including prostate cancer. It is recommended that all referrals be considered by a multidisciplinary team to select appropriate cases.

Proton beam therapy of parapapillary choroidal melanoma

PURPOSE

To analyze the functional outcome with regard to the development of visual acuity and radiation-induced optic neuropathy of patients with parapapillary choroidal melanoma treated with proton beam therapy.

DESIGN

Clinical case series, retrospective study.

METHODS

We evaluated 147 consecutive patients with parapapillary choroidal melanoma who received proton beam therapy as primary tumor treatment at the Helmholtz Center in Berlin from 1998 to 2005. A cumulative dose of 60 Cobalt Gray Equivalents (CGE) was delivered to the tumor and the optic disc received a minimum of 50 CGE. Kaplan-Meier analysis was used to assess ocular outcome and survival rates. For trend analysis of functional development, Wilcoxon-Mann-Whitney U test was used to compare the medians of 2 groups and Kruskal-Wallis test was used in the case of more than 2 groups.

RESULTS

The mean follow-up time was 6.5 years (range 0.3-11.7 years). The most common side effects were radiation-induced optic neuropathy, retinopathy, and cataract. The median visual acuity before and within the first year after therapy was 0.4 logMAR (20/50), lapsing to 1.3 logMAR (20/400) after 3 years and 1.4 logMAR (20/500) after 5 years. During follow-up, no light perception developed in 17 cases (11.6%), mostly attributed to radiation-induced retinopathy, optic neuropathy, and secondary glaucoma. Enucleation was carried out in 14 patients (9.5%) because of local recurrence or severe side effects.

CONCLUSION

Radiation-induced optic neuropathy is an expected issue after proton beam therapy of parapapillary choroidal melanoma, and visual impairment is common during long-term follow-up, but some useful vision can be preserved in a considerable number of patients.

Uveal melanoma treated with iodine-125 episcleral plaque: an analysis of dose on disease control and visual outcomes

PURPOSE

To investigate, in the treatment of uveal melanomas, how tumor control, radiation toxicity, and visual outcomes are affected by the radiation dose at the tumor apex.

METHODS AND MATERIALS

A retrospective review was performed to evaluate patients treated for uveal melanoma with (125)I plaques between 1988 and 2010. Radiation dose is reported as dose to tumor apex and dose to 5 mm. Primary endpoints included time to local failure, distant failure, and death. Secondary endpoints included eye preservation, visual acuity, and radiation-related complications. Univariate and multivariate analyses were performed to determine associations between radiation dose and the endpoint variables.

RESULTS

One hundred ninety patients with sufficient data to evaluate the endpoints were included. The 5-year local control rate was 91%. The 5-year distant metastases rate was 10%. The 5-year overall survival rate was 84%. There were no differences in outcome (local control, distant metastases, overall survival) when dose was stratified by apex dose quartile (<69 Gy, 69-81 Gy, 81-89 Gy, >89 Gy). However, increasing apex dose and dose to 5-mm depth were correlated with greater visual acuity loss (P=.02, P=.0006), worse final visual acuity (P=.02, P<.0001), and radiation complications (P<.0001, P=.0009). In addition, enucleation rates were worse with increasing quartiles of dose to 5 mm (P=.0001).

CONCLUSIONS

Doses at least as low as 69 Gy prescribed to the tumor apex achieve rates of local control, distant metastasis-free survival, and overall survival that are similar to radiation doses of 85 Gy to the tumor apex, but with improved visual outcomes.

New strategies in radiation therapy: exploiting the full potential of protons

Protons provide significant dosimetric advantages compared with photons because of their unique depth-dose distribution characteristics. However, they are more sensitive to the effects of intra- and intertreatment fraction anatomic variations and uncertainties in treatment setup. Furthermore, in the current practice of proton therapy, the biologic effectiveness of protons relative to photons is assumed to have a generic fixed value of 1.1. However, this is a simplification, and it is likely higher in different portions of the proton beam. Current clinical practice and trials have not fully exploited the unique physical and biologic properties of protons. Intensity-modulated proton therapy, with its ability to manipulate energies (in addition to intensities), provides an entirely new dimension, which, with ongoing research, has considerable potential to increase the therapeutic ratio.

Long-term results of carbon ion radiation therapy for locally advanced or unfavorably located choroidal melanoma: usefulness of CT-based 2-port orthogonal therapy for reducing the incidence of neovascular glaucoma

PURPOSE

To determine the long-term results of carbon ion radiation therapy (C-ion RT) in patients with choroidal melanoma, and to assess the usefulness of CT-based 2-port irradiation in reducing the risk of neovascular glaucoma (NVG).

METHODS AND MATERIALS

Between January 2001 and February 2012, a total of 116 patients with locally advanced or unfavorably located choroidal melanoma received CT-based C-ion RT. Of these patients, 114 were followed up for more than 6 months and their data analyzed. The numbers of T3 and T2 patients (International Union Against Cancer [UICC], 5th edition) were 106 and 8, respectively. The total dose of C-ion RT varied from 60 to 85 GyE, with each dose given in 5 fractions. Since October 2005, 2-port therapy (51 patients) has been used in an attempt to reduce the risk of NVG. A dose-volume histogram analysis was also performed in 106 patients.

RESULTS

The median follow-up was 4.6 years (range, 0.5-10.6 years). The 5-year overall survival, cause-specific survival, local control, distant metastasis-free survival, and eye retention rates were 80.4% (95% confidence interval 89.0%-71.8%), 82.2% (90.6%-73.8%), 92.8% (98.5%-87.1%), 72.1% (81.9%-62.3%), and 92.8% (98.1%-87.5%), respectively. The overall 5-year NVG incidence rate was 35.9% (25.9%-45.9%) and that of 1-port group and 2-port group were 41.6% (29.3%-54.0%) and 13.9% (3.2%-24.6%) with statistically significant difference (P<.001). The dose-volume histogram analysis showed that the average irradiated volume of the iris-ciliary body was significantly lower in the non-NVG group than in the NVG group at all dose levels, and significantly lower in the 2-port group than in the 1-port group at high dose levels.

CONCLUSIONS

The long-term results of C-ion RT for choroidal melanoma are satisfactory. CT-based 2-port C-ion RT can be used to reduce the high-dose irradiated volume of the iris-ciliary body and the resulting risk of NVG.