Eye retention after proton beam radiotherapy for uveal melanoma

Transplantable Melanomas in Hamsters and Gerbils as Models for Human Melanoma. Sensitization in Melanoma Radiotherapy-From Animal Models to Clinical Trials

The focus of the present review is to investigate the role of melanin in the radioprotection of melanoma and attempts to sensitize tumors to radiation by inhibiting melanogenesis. Early studies showed radical scavenging, oxygen consumption and adsorption as mechanisms of melanin radioprotection. Experimental models of melanoma in hamsters and in gerbils are described as well as their use in biochemical and radiobiological studies, including a spontaneously metastasizing ocular model. Some results from in vitro studies on the inhibition of melanogenesis are presented as well as radio-chelation therapy in experimental and clinical settings. In contrast to cutaneous melanoma, uveal melanoma is very successfully treated with radiation, both using photon and proton beams. We point out that the presence or lack of melanin pigmentation should be considered, when choosing therapeutic options, and that both the experimental and clinical data suggest that melanin could be a target for radiosensitizing melanoma cells to increase efficacy of radiotherapy against melanoma.

Technical Note: Feasibility study of titanium markers in choroidal melanoma localization for proton beam radiation therapy

PURPOSE

The purpose of this study is to explore the feasibility of the use of titanium fiducial markers to minimize the metallic artifact seen with tantalum markers which causes significant distortion on postoperative orbital CT scans.

METHOD

We designed and constructed the titanium markers in the shop of Crocker Nuclear Laboratory, UC Davis, CA. The markers were placed on an eyeball phantom. The eyeball was inserted into the Rando phantom in the orbital space. The Rando phantom was imaged with coplanar x rays on Nucletron simulator at UCSF, on digital panel on the eye beam line at CNL eye treatment facility and on CT scanner at UCSF.

RESULTS

The titanium markers can be clearly seen on the hard copy of x rays and on digital panel. The CT scan of an orbit using tantalum markers on the right eye and titanium markers on the left eye shows the metal artifact from tantalum markers. Titanium markers show very little distortion on CT images.

CONCLUSION

The present study describes these markers and their relative benefit in comparison with tantalum marker, which has been used for localizing ocular tumor for decades.

Feasibility of Image-Guided Robotic Radiotherapy using Three Fractions for Uveal Melanoma

Aims

A retrospective study was performed to demonstrate the feasibility and efficacy of 3-fraction image-guided robotic stereotactic radiotherapy (fSRT) for uveal melanoma.

Materials and Methods

Six patients with medium-sized or large tumors, who declined enucleation, were enrolled. The gross tumor volume (GTV) ranged from 454 to 2185 mm3. The total doses included 36 or 39 Gy in 3 fractions.

Results

Follow-up ranged from 19 to 40 months. In 5 patients, the tumor mass gradually underwent an average 24.5% size reduction. All 3 patients with a GTV <1000 mm3 had a functional eye, while 3 patients with a GTV ≥1000 mm3 did not have a functional eye. Radiation-induced complications occurred to some degree in all patients. However, complications that required enucleation were not detected.

Conclusion

We suggest that image-guided robotic radiotherapy using 3 fractions is a feasible and safe treatment option for patients with uveal melanoma. In cases of medium-sized and large tumors, fSRT could be used as an alternative treatment for cases ineligible for brachytherapy, but a longer follow-up and a larger number of patients are required to confirm the suitability of the method.

Proton Beam Radiotherapy of Uveal Melanoma: Italian Patients Treated in Nice, France

Purpose

To evaluate the results of 15 years of experience with proton beam radiotherapy in the treatment of intraocular melanoma, and to determine univariate and multivariate risk factors for local failure, eye retention, and survival.

Methods

A total of 368 cases of intraocular melanoma were treated with proton beam radiotherapy at Centre Lacassagne Cyclotron Biomedical of Nice, France, between 1991 and 2006. Actuarial methods were used to evaluate rate of local tumor control, eye retention, and survival after proton beam radiotherapy. Cox regression models were extracted to evaluate univariate risk factors, while regularized least squares algorithm was used to have a multivariate classification model to better discriminate risk factors.

Results

Tumor relapse occurred in 8.4% of the eyes, with a median recurrence time of 46 months. Enucleation was performed on 11.7% of the eyes after a median time of 49 months following proton beam; out of these, 29 eyes were enucleated due to relapse and 16 due to other causes. The univariate regression analysis identified tumor height and diameter as primary risk factors for enucleation. Regularized least squares analysis demonstrated the higher effectiveness of a multivariate model of five risk factors (macula distance, optic disc distance, tumor height, maximum diameter, and age) in discriminating relapsed vs nonrelapsed patients.

Conclusions

This data set, which is the largest in Italy with relatively long-term follow-up, demonstrates that a high rate of tumor control, survival, and eye retention were achieved after proton beam irradiation, as in other series.

Photodynamic Therapy for Eye Cancer

Photodynamic therapy is well-established as a treatment for a number of conditions in ophthalmology, principally in the field of medical retina, but less so in ocular oncology. Cancer of the eye is rare, the commonest lesions to affect the globe being choroidal melanoma (as a primary malignancy) and choroidal metastases (a secondary malignancy). The mainstay of treatment of such lesions remains radiotherapy in various forms, however, photodynamic therapy does have a useful role to play in the management of such patients. In this article, I hope to review the current indications, treatment regimes, and the risks and benefits of photodynamic therapy (PDT) as a treatment for eye cancer.

Gamma Knife Stereotactic Radiosurgery for the Treatment of Primary and Metastatic Ocular Malignancies

BACKGROUND

Gamma knife radiosurgery (GKR) can be used for precise targeting of malignant lesions of the CNS when brachytherapy is not an appropriate option.

OBJECTIVES

This study reports treatment technique, efficacy, and radiation-induced adverse effects in patients with primary and metastatic ocular lesions treated with Leksell GKR.

METHODS

A retrospective, single-institution review was conducted of 28 patients with primary or metastatic ocular disease, treated from 2000 to 2014. The dose to margin was 17-27 Gy (maximum dose 28-54 Gy). Primary outcomes included overall survival (OS), local control, progression-free survival (PFS), and enucleation.

RESULTS

The median age at diagnosis was 70 years, and the median follow-up was 26.4 months. Of the 28 patients, 11 (39%) had metastatic ocular disease, and 17 (61%) were diagnosed with primary ocular melanoma (stage T2a-T4e). The average maximum dose and dose to margin were 41 and 21 Gy, respectively. The mean dose to the optic nerve was 12.6 Gy. The 5-year OS was 46% (95% CI: 23.6-68.4%) for the entire cohort; the 5-year PFS for M0 patients who presented with primary ocular melanoma lesions was 90% (95% CI: 71-100%). Only 1 patient required enucleation after radiation treatment.

CONCLUSION

GKR is an effective option, with acceptable levels of toxicity, in the treatment of primary and metastatic ocular lesions.

Clinical and Research Activities at the CATANA Facility of INFN-LNS: From the Conventional Hadrontherapy to the Laser-Driven Approach

The CATANA proton therapy center was the first Italian clinical facility making use of energetic (62 MeV) proton beams for the radioactive treatment of solid tumors. Since the date of the first patient treatment in 2002, 294 patients have been successful treated whose majority was affected by choroidal and iris melanomas. In this paper, we report on the current clinical and physical status of the CATANA facility describing the last dosimetric studies and reporting on the last patient follow-up results. The last part of the paper is dedicated to the description of the INFN-LNS ongoing activities on the realization of a beamline for the transport of laser-accelerated ion beams for future applications. The ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) project is introduced and the main scientific aspects will be described.

Intravitreal dexamethasone implant (Ozurdex®) for exudative retinal detachment after proton beam therapy for choroidal melanoma

PURPOSE

To evaluate the efficacy and safety of intravitreal 0.7-mg dexamethasone implant (DEX-I) (Ozurdex®) in the treatment of extensive exudative retinal detachment (RD) associated with uveal melanoma treated using proton beam therapy (PBT).

METHODS

Data from 10 patients with exudative RD after PBT treated with intravitreal injection of 0.7-mg DEX-I were reviewed retrospectively. The main outcome measures were resolution of exudative RD, visual acuity, and safety profile.

RESULTS

Mean age was 55.6 years (range 34-85). Mean time between PBT and DEX-I was 12.4 months (range 3-25). Mean follow-up was 9.9 months (range 4-15). Intravitreal Ozurdex® reduced exudative RD in 7 cases (70%) on average 3.1 months after injection with complete resolution of RD in 6 of these (60%). For half of the patients, their level of vision remained stable; the other half experienced a deterioration in visual acuity at the end of follow-up. No adverse effects were observed.

CONCLUSIONS

In this small case series, treatment with intravitreal DEX-I reduced exudative RD in the majority of cases and had an acceptable safety profile.

Mechanisms of phosphenes in irradiated patients

Anomalous visual perceptions have been reported in various diseases of the retina and visual pathways or can be experienced under specific conditions in healthy individuals. Phosphenes are perceptions of light in the absence of ambient light, occurring independently of the physiological and classical photonic stimulation of the retina. They are a frequent symptom in patients irradiated in the region of the central nervous system (CNS), head and neck and the eyes. Phosphenes have historically been attributed to complex physical phenomena such as Cherenkov radiation. While phosphenes are related to Cherenkov radiation under high energy photon/electron irradiation conditions, physical phenomena are unlikely to be responsible for light flashes at energies used for ocular proton therapy. Phosphenes may involve a direct role for ocular photoreceptors and possible interactions between cones and rods. Other mechanisms involving the retinal ganglion cells or ultraweak biophoton emission and rhodopsin bleaching after exposure to free radicals are also likely to be involved. Despite their frequency as shown in our preliminary observations, phosphenes have been underreported probably because their mechanism and impact are poorly understood. Recently, phosphenes have been used to restore the vision and whether they might predict vision loss after therapeutic irradiation is a current field of investigation. We have reviewed and also investigated here the mechanisms related to the occurrence of phosphenes in irradiated patients and especially in patients irradiated by proton therapy for ocular tumors.

Identification of novel chemotherapeutic strategies for metastatic uveal melanoma

Melanoma of the uveal tract accounts for approximately 5% of all melanomas and represents the most common primary intraocular malignancy. Despite improvements in diagnosis and more effective local therapies for primary cancer, the rate of metastatic death has not changed in the past forty years. In the present study, we made use of bioinformatics to analyze the data obtained from three public available microarray datasets on uveal melanoma in an attempt to identify novel putative chemotherapeutic options for the liver metastatic disease. We have first carried out a meta-analysis of publicly available whole-genome datasets, that included data from 132 patients, comparing metastatic vs. non metastatic uveal melanomas, in order to identify the most relevant genes characterizing the spreading of tumor to the liver. Subsequently, the L1000CDS² web-based utility was used to predict small molecules and drugs targeting the metastatic uveal melanoma gene signature. The most promising drugs were found to be Cinnarizine, an anti-histaminic drug used for motion sickness, Digitoxigenin, a precursor of cardiac glycosides, and Clofazimine, a fat-soluble iminophenazine used in leprosy. In vitro and in vivo validation studies will be needed to confirm the efficacy of these molecules for the prevention and treatment of metastatic uveal melanoma.

Dry Eye Syndrome After Proton Therapy of Ocular Melanomas

PURPOSE

To investigate whether proton therapy (PT) performs safely in superotemporal melanomas, in terms of risk of dry-eye syndrome (DES).

METHODS AND MATERIALS

Tumor location, DES grade, and dose to ocular structures were analyzed in patients undergoing PT (2005-2015) with 52 Gy (prescribed dose, not accounting for biologic effectiveness correction of 1.1). Prognostic factors of DES and severe DES (sDES, grades 2-3) were determined with Cox proportional hazard models. Visual acuity deterioration and enucleation rates were compared by sDES and tumor locations.

RESULTS

Median follow-up was 44 months (interquartile range, 18-60 months). Of 853 patients (mean age, 64 years), 30.5% had temporal and 11.4% superotemporal tumors. Five-year incidence of DES and sDES was 23.0% (95% confidence interval [CI] 19.0%-27.7%) and 10.9% (95% CI 8.2%-14.4%), respectively. Multivariable analysis showed a higher risk for sDES in superotemporal (hazard ratio [HR] 5.82, 95% CI 2.72-12.45) and temporal tumors (HR 2.63, 95% CI 1.28-5.42), age ≥70 years (HR 1.90, 95% CI 1.09-3.32), distance to optic disk ≥5 mm (HR 2.71, 95% CI 1.52-4.84), ≥35% of retina receiving 12 Gy (HR 2.98, 95% CI 1.54-5.77), and eyelid rim irradiation (HR 2.68, 95% CI 1.49-4.80). The same risk factors were found for DES. Visual acuity deteriorated more in patients with sDES (0.86 ± 1.10 vs 0.64 ± 0.98 logMAR, P=.034) but not between superotemporal/temporal and other locations (P=.890). Enucleation rates were independent of sDES (P=.707) and tumor locations (P=.729).

CONCLUSIONS

Severe DES was more frequent in superotemporal/temporal melanomas. Incidence of vision deterioration and enucleation was no higher in patients with superotemporal melanoma than in patients with tumors in other locations. Tumor location should not contraindicate PT.

Evisceration and ocular tumors: What are the consequences?

PURPOSE

Evisceration can be performed for blind, painful eyes. This surgery can promote the dissemination of tumor cells within the orbit if an ocular tumor has been missed preoperatively.

METHODS

We reviewed the medical records of patients who were eviscerated for blind, painful eyes between 2009 and 2014 and who were referred after the surgery to the Institut Curie or the Rothschild Foundation in Paris. We included the patients with a histological diagnosis of ocular tumor or orbital recurrence. Cytogenetic analysis was performed whenever possible.

RESULTS

Four patients turned out to have an ocular tumor after evisceration (two choroidal melanomas, a rhabdoid tumor and an adenocarcinoma of the retinal pigment epithelium); two had a history of prior ocular trauma. The tumors were diagnosed either on histological analysis of the intraocular contents (2 patients) or biopsy of orbital recurrence (2 patients). Prior to evisceration, fundus examination was not performed in 3 patients. One had preoperative imaging but no intraocular tumor was suspected. At the time of this study, 3 patients had had an orbital recurrence and died. We also found 2 patients who had an evisceration despite a past history of choroidal melanoma treated with proton beam therapy.

CONCLUSION

We showed that evisceration of eyes with unsuspected ocular malignancies was associated with a poor prognosis due to orbital recurrence and metastasis. The evisceration specimen should therefore always be sent for histological analysis in order to perform prompt adjuvant orbital radiotherapy if an ocular tumor is found.

Uveal melanoma: From diagnosis to treatment and the science in between

Melanomas of the choroid, ciliary body, and iris of the eye are collectively known as uveal melanomas. These cancers represent 5% of all melanoma diagnoses in the United States, and their age-adjusted risk is 5 per 1 million population. These less frequent melanomas are dissimilar to their more common cutaneous melanoma relative, with differing risk factors, primary treatment, anatomic spread, molecular changes, and responses to systemic therapy. Once uveal melanoma becomes metastatic, therapy options are limited and are often extrapolated from cutaneous melanoma therapies despite the routine exclusion of patients with uveal melanoma from clinical trials. Clinical trials directed at uveal melanoma have been completed or are in progress, and data from these well designed investigations will help guide future directions in this orphan disease. Cancer 2016;122:2299-2312. © 2016 American Cancer Society.

Innovative radiotherapy of sarcoma: Proton beam radiation

This review on proton beam radiotherapy (PBT) focusses on an historical overview, cost-effectiveness, techniques, acute and late toxicities and clinical results of PBT for sarcoma patients. PBT has gained its place among the armamentarium of modern radiotherapy techniques. For selected patients, it can be cost-effective.

Outcomes After Proton Beam Therapy for Large Choroidal Melanomas in 492 Patients

PURPOSE

To evaluate proton beam therapy (PBT) as a means to preserve the eye and spare some vision while not deteriorating survival in patients with large choroidal melanomas.

DESIGN

This is a retrospective, consecutive cohort study of patients with T3-4 choroidal melanomas according to the 7th edition of the American Joint Cancer Classification treated with PBT over a 24-year period.

RESULTS

A total of 492 patients were included. Mean (range) tumor thickness and diameter were 8.77 (2-15) mm and 14.91 (7-24.1) mm, respectively. Mean macular and optic disc distance were 4.56 (0-19.9) mm and 4.59 (0-22.1) mm, respectively. Mean follow-up was 61.9 months. Rates of neovascular glaucoma (NVG) and enucleation (mainly for local recurrence or NVG) were 27.0% and 19.5%, respectively. Enucleation rates decreased over time. The 5-year local control was 94%. Mean baseline visual acuity was 20/63, and visual acuity ≥20/200 was preserved in 20% of patients. At 5 years, 25% of T3 patients presented with metastasis; overall and specific survival rates were 65% and 75%, respectively.

CONCLUSION

Local control after PBT remained good with increasingly manageable complications and fewer secondary enucleations over time for these large melanomas. As PBT does not seem to deteriorate survival in these patients having a high risk of metastasis, PBT may be considered as a safe and efficient alternative to enucleation in patients with large choroidal melanoma, and may help to spare some vision.

Protons, Photons, and the Prostate - Is There Emerging Evidence in the Ongoing Discussion on Particle Therapy for the Treatment of Prostate Cancer?

Proton therapy is actively and repeatedly discussed within the framework of particle therapy for the treatment of prostate cancer (PC). The argument in favor of treating the prostate with protons is partly financial: given that small volumes are treated, treatment times are low, resulting in a hypothetical high patient throughput. However, such considerations should not form the basis of medical decision-making. There are also physical and biological arguments which further support the use of particle therapy for PC. The only relevant randomized data currently available is the study by Zietman and colleagues, comparing a high to a low proton boost, resulting in a significant increase in PSA-free survival in the experimental (high dose) arm (1). With modern photon treatments and image-guided radiotherapy (IGRT), equally high doses can be applied with photons and, thus, a randomized trial comparing high-end photons to protons is warranted. For high-linear energy transfer (LET) particles, such as carbon ions, the increase in relative biological effectiveness could potentially convert into an improvement in outcome. Additionally, through the physical differences of protons and carbon ions, the steeper dose gradient with carbon ions and the lack of beam broadening in the carbon beam lead to a superior dose distribution supporting the idea of hypofractionation. Biological and clinical data are emerging, however, has practice-changing evidence already arrived?

Secondary Enucleations for Uveal Melanoma: A 7-Year Retrospective Analysis

PURPOSE

To describe the indications for secondary enucleations in uveal melanoma and analyze associations and outcomes.

DESIGN

Retrospective interventional case series.

METHODS

Data of patients who underwent secondary enucleation for uveal melanoma in the London Ocular Oncology Service, between 2008 and 2014, were retrieved from medical records analyzed. Cox regression model was performed to analyze associations with secondary enucleation and metastases and Kaplan-Meier estimates to assess the probability of metastatic spread and death.

RESULTS

During the study period 515 enucleations were performed for uveal melanoma, 99 (19%) of which were secondary enucleations. Tumors were located at the ciliary body in 21 eyes (21%), juxtapapillary in 31 (31%), and choroid elsewhere in 47 (48%). Primary treatment included Ru(106) plaque radiotherapy, proton beam radiotherapy, and transpupillary thermotherapy in 85, 11, and 3 eyes, respectively. Indications for secondary enucleation were tumor recurrence in 60 (61%), neovascular glaucoma in 21 (21%), and tumor nonresponse in 18 eyes (18%). Twenty patients (20%) were diagnosed with metastasis and 12 out of 20 died of metastatic spread. On multivariate analysis, juxtapapillary tumor location was found to associate with tumor nonresponse (P = .004) and nonresponding patients with metastatic spread (P = .04).

CONCLUSIONS

Indications for secondary enucleations for uveal melanoma were tumor recurrence, neovascular glaucoma, and tumor nonresponse. This review identified a possible high-risk group (nonresponse), which proved radioresistant to treatment. These tumors were more frequently found in the juxtapapillary location and were associated with metastatic spread.

A Multidisciplinary Orbit-Sparing Treatment Approach That Includes Proton Therapy for Epithelial Tumors of the Orbit and Ocular Adnexa

PURPOSE

Postoperative radiation is often indicated in the treatment of malignant epithelial tumors of the orbit and ocular adnexa. We present details of radiation technique and toxicity data after orbit-sparing surgery followed by adjuvant proton radiation therapy.

METHODS AND MATERIALS

Twenty patients underwent orbit-sparing surgery followed by proton therapy for newly diagnosed malignant epithelial tumors of the lacrimal gland (n=7), lacrimal sac/nasolacrimal duct (n=10), or eyelid (n=3). Tumor characteristics, treatment details, and visual outcomes were obtained from medical records. Acute and chronic toxicity were prospectively scored using Common Terminology Criteria for Adverse Events version 4.0.

RESULTS

The median radiation dose was 60 Gy(RBE) (relative biological effectiveness; [range 50-70 Gy]); 11 patients received concurrent chemotherapy. Dose to ipsilateral anterior optic structures was reduced in 13 patients by having them gaze away from the target during treatment. At a median follow-up time of 27.1 months (range 2.6-77.2 months), no patient had experienced local recurrence; 1 had regional and 1 had distant recurrence. Three patients developed chronic grade 3 epiphora, and 3 developed grade 3 exposure keratopathy. Four patients experienced a decrease in visual acuity from baseline but maintained vision sufficient to perform all activities of daily living without difficulty. Patients with grade ≥3 chronic ocular toxicity had higher maximum dose to the ipsilateral cornea (median 46.3 Gy[RBE], range 36.6-52.7 Gy[RBE] vs median 37.4 Gy[RBE], range 9.0-47.3 Gy(RBE); P=.017).

CONCLUSIONS

Orbit-sparing surgery for epithelial tumors of the orbit and ocular adnexa followed by proton therapy successfully achieved disease control and was well tolerated. No patient required orbital exenteration or enucleation. Chronic grade 3 toxicity was associated with high maximum dose to the cornea. An eye-deviation technique can be used to limit the maximum corneal dose to <35 Gy(RBE).

Outcomes of treatment with stereotactic radiosurgery or proton beam therapy for choroidal melanoma

AIM

To present our experience of the use of stereotactic radiosurgery and proton beam therapy to treat posterior uveal melanoma over a 10 year period.

METHODS AND MATERIALS

Case notes of patients treated with stereotactic radiosurgery (SRS), or Proton beam therapy (PBT) for posterior uveal melanoma were reviewed. Data collected included visual acuity at presentation and final review, local control rates, globe retention and complications. We analysed post-operative visual outcomes and if visual outcomes varied with proximity to the optic nerve or fovea.

RESULTS

191 patients were included in the study; 85 and 106 patients received Stereotactic radiosurgery and Proton beam therapy, respectively. Mean follow up period was 39 months in the SRS group and 34 months in the PBT group. Both treatments achieved excellent local control rates with eye retention in 98% of the SRS group and 95% in the PBT group. The stereotactic radiosurgery group showed a poorer visual prognosis with 65% losing more than 3 lines of Snellen acuity compared to 45% in the PBT group. 33% of the SRS group and 54% of proton beam patients had a visual acuity of 6/60 or better.

CONCLUSIONS

Stereotactic radiosurgery and proton beam therapy are effective treatments for larger choroidal melanomas or tumours unsuitable for plaque radiotherapy. Our results suggest that patients treated with proton beam therapy retain better vision post-operatively; however, possible confounding factors include age, tumour location and systemic co-morbidities. These factors as well as the patient's preference should be considered when deciding between these two therapies.

Optimization of a general-purpose, actively scanned proton beamline for ocular treatments: Geant4 simulations

The Italian National Center for Hadrontherapy (CNAO, Centro Nazionale di Adroterapia Oncologica), a synchrotron‐based hospital facility, started the treatment of patients within selected clinical trials in late 2011 and 2012 with actively scanned proton and carbon ion beams, respectively. The activation of a new clinical protocol for the irradiation of uveal melanoma using the existing general‐purpose proton beamline is foreseen for late 2014. Beam characteristics and patient treatment setup need to be tuned to meet the specific requirements for such a type of treatment technique. The aim of this study is to optimize the CNAO transport beamline by adding passive components and minimizing air gap to achieve the optimal conditions for ocular tumor irradiation. The CNAO setup with the active and passive components along the transport beamline, as well as a human eye‐modeled detector also including a realistic target volume, were simulated using the Monte Carlo Geant4 toolkit. The strong reduction of the air gap between the nozzle and patient skin, as well as the insertion of a range shifter plus a patient‐specific brass collimator at a short distance from the eye, were found to be effective tools to be implemented. In perspective, this simulation toolkit could also be used as a benchmark for future developments and testing purposes on commercial treatment planning systems.

PACS numbers: 21.30Fe, 24.10.Lx, 29.20.dk, 29.27.Eg, 29.85.Fj

Prophylactic use of bevacizumab to avoid anterior segment neovascularization following proton therapy for uveal melanoma

PURPOSE

To investigate whether the prophylactic use of bevacizumab reduces the rate of rubeosis after proton therapy for uveal melanoma and improves the possibility to treat ischemic, reapplicated retina with laser photocoagulation.

DESIGN

Comparative retrospective case series.

METHODS

Uveal melanoma patients with ischemic retinal detachment and treated with proton therapy were included in this institutional study. Twenty-four eyes received prophylactic intravitreal bevacizumab injections and were compared with a control group of 44 eyes without bevacizumab treatment. Bevacizumab injections were performed at the time of tantalum clip insertion and were repeated every 2 months during 6 months, and every 3 months thereafter. Ultra-widefield angiography allowed determination of the extent of retinal ischemia, which was treated with laser photocoagulation after retinal reapplication. Main outcome measures were the time to rubeosis, the time to retinal reattachment, and the time to laser photocoagulation of ischemic retina.

RESULTS

Baseline characteristics were balanced between the groups, except for thicker tumors and larger retinal detachments in the bevacizumab group, potentially to the disadvantage of the study group. Nevertheless, bevacizumab prophylaxis significantly reduced the rate of iris rubeosis from 36% to 4% (log-rank test P = .02) and tended to shorten the time to retinal reapplication until laser photocoagulation of the nonperfusion areas could be performed.

CONCLUSIONS

Prophylactic intravitreal bevacizumab in patients treated with proton therapy for uveal melanoma with ischemic retinal detachment prevented anterior segment neovascularization, until laser photocoagulation to the reapplied retina could be performed.

Transpalpebral proton beam radiotherapy of choroidal melanoma

BACKGROUND

Collateral damage to upper eyelid margin during proton beam radiotherapy (PBR) for choroidal melanoma may cause squamous metaplasia of the tarsal conjunctiva with keratinisation, corneal irritation, discomfort and, rarely, corneal perforation. We evaluated transpalpebral PBR as a means of avoiding collateral damage to the upper eyelid margin without increasing the risk of failure of local tumour control.

METHODS

Retrospective study of consecutive patients who underwent PBR for choroidal melanoma between 1992 and 2007 at the Royal Liverpool University Hospital and the Douglas Cyclotron at Clatterbridge Cancer Centre, UK.

RESULTS

Sixty-three patients were included in this study. Mean basal tumour diameter and tumour thickness were 11.8 mm and 3.6 mm, respectively. PBR mean beam range and modulation were 26.5 mm and 16.9 mm respectively. The eyelid margin was included in the radiation field in 15 (24%) eyes. The median follow-up was 2.5 years. Local tumour recurrence developed in 2 (3.2%) patients. In these two cases that developed tumour recurrence the transpalpebral treatment did not involve the eyelid margin. Six (9.5%) patients died of metastatic disease. No eyelid or ocular surface problems developed in any of the 48 patients who were treated without eyelid rim involvement, while 7 of the 15 patients with unavoidable irradiation of the eyelid rim developed some degree of madarosis. These seven patients all received more than 26.55 proton Gy to the eyelid margin. Symptoms, such as grittiness occurred in 12% of 48 patients without eyelid margin irradiation as compared with 53% of 15 patients whose lid margin was irradiated.

CONCLUSIONS

Transpalpebral PBR of choroidal melanoma avoids eyelid and ocular surface complications without increasing failure of local tumour control.

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

AIM OF THE STUDY

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Assessment of the effect of iris colour and having children on 5-year risk of death after diagnosis of uveal melanoma: a follow-up study

Background

To examine the all-cause mortality and uveal melanoma specific mortality among newly diagnosed uveal melanoma patients after five years. Furthermore, we assess of the effect of iris colour and having children on 5-year risk of death after diagnosis of uveal melanoma. Therefore, we assess the performance of an individual prediction model of survival from uveal melanoma.

Methods

A cohort of 459 patients aged 45 to 79 years with newly diagnosed uveal melanoma was recruited between 2002 and 2004 from the Division of Ophthalmology, University of Essen, Germany. Survival probabilities were estimated by Kaplan-Meier survival analysis. The clinical and histopathological characteristics were obtained from medical records. Iris colour and childbearing history were assessed at baseline by a computer-assisted telephone interview. We used crude and multivariable Cox proportional hazards regression to estimate unadjusted and adjusted hazard ratios (HR) and corresponding 95% confidence intervals (95%CIs) with respect to death from uveal melanoma and death from all causes. We used the Cox model to estimate adjusted probabilities of primary events. For computing Harrell’s C statistics, we used a Cox model including the prognostics factors gender, age at diagnosis, ciliary body involvement, largest basal tumour diameter, and iris colour.

Results

The 5-year uveal melanoma-specific survival probability was 82.9% (95% CI: 79.1-86.3). Main prognostic factors for the death of uveal melanoma were ciliary body involvement (HR: 1.7 (95% CI:1.0-2.8)), largest basal tumour diameter >15 mm HR: 7.0 (95% CI: 3.5-13.9), light iris colour (HR: 2.3 (95% CI: 0.9-5.8), having children (HR: 0.6 (95% CI: 0.2 - 1.7)), and gender (HR: 0.7 (95% CI: 0.4-1.1)). The value of the bootstrap-corrected C statistics was 0.76 (95% CI: 0.74-0.77).

Conclusion

Beyond the established prognostic factors, light iris colour also appears to be a prognostic factor for death from uveal melanoma.

Quantification of dose perturbations induced by external and internal accessories in ocular proton therapy and evaluation of their dosimetric impact

PURPOSE

Proton scattering on beam shaping devices and protons slowing down on media with different densities within the treatment volume may produce dose perturbations and range variations that are not predicted by treatment planning systems. The aim of this work was to assess the dosimetric impact of elements present in ocular proton therapy treatments that may disturb the prescribed treatment plan. Both distal beam shaping devices and intraocular elements were considered.

METHODS

A wedge filter, tantalum fiducial marker, hemispherical compensator, two intraocular endotamponades (densities 0.97 and 1.92 g cm(-3)) and an intraocular eye lens (IOL) were considered in the study. For these elements, longitudinal dose distributions were measured and∕or calculated in water in beam alignment for a clinical spread-out Bragg peak. Under the same conditions, the unperturbed dose distributions were similarly measured and∕or calculated in the absence of the element. The dosimetric impact was assessed by comparison of unperturbed and perturbed dose distributions. Measurements and calculations were carried out with two methods. Measurements are based on EBT3 films with dedicated software, which makes use of a calibration curve and correction for the quenching effect. Calculations are based on the Monte Carlo (MC) code MCNPX and reproduce the experimental conditions. Both dose maps are obtained with a resolution of 300 dpi.

RESULTS

The degree of disturbance of distal beam shaping devices is low for the wedge filter (2% overdose ripple all along the central axis) and moderate for the hemispherical compensator (two bands of variable overdose of up to 10% downstream the compensator lateral edges and -5% underdose on the plateau at off-axis distance of 5 cm). Tantalum clips produce important dose shadows (-20% behind the clip parallel to the beam and range reduction of 1.1 mm) and bands of overdose (15%). The presence of endotamponades modifies the dose distribution very significantly (-5% underdose on the plateau and 3 mm range prolongation for the tamponade with density 0.97 g cm(-3) and -15% underdose on plateau and 8 mm range reduction for that with density 1.92 g cm(-3)). No dose perturbations were found for the IOL. The high performance of EBT3 film and MC tools used was confirmed and good agreement was found between them (percentage of pixels passing the gamma test >87%).

CONCLUSIONS

The degree of disturbance by external beam shaping devices remains low in ocular proton therapy and can be reduced by bringing accessories closer to the eye. Tantalum fiducial markers must be located in such a way that dose perturbation is not projected on the tumor. The treatment of patients with intraocular endotamponades must be carefully managed. It is fundamental that radiation oncologists and medical physicists are informed about the presence of such substances prior to the treatment.

The American Brachytherapy Society consensus guidelines for plaque brachytherapy of uveal melanoma and retinoblastoma

PURPOSE

To present the American Brachytherapy Society (ABS) guidelines for plaque brachytherapy of choroidal melanoma and retinoblastoma.

METHODS AND MATERIALS

An international multicenter Ophthalmic Oncology Task Force (OOTF) was assembled to include 47 radiation oncologists, medical physicists, and ophthalmic oncologists from 10 countries. The ABS-OOTF produced collaborative guidelines, based on their eye cancer-specific clinical experience and knowledge of the literature. This work was reviewed and approved by the ABS Board of Directors as well as within the journal's peer-reivew process.

RESULTS

The ABS-OOTF reached consensus that ophthalmic plaque radiation therapy is best performed in subspecialty brachytherapy centers. Quality assurance, methods of plaque construction, and dosimetry should be consistent with the 2012 joint guidelines of the American Association of Physicists in Medicine and ABS. Implantation of plaque sources should be performed by subspecialty-trained surgeons. Although there exist select restrictions related to tumor size and location, the ABS-OOTF agreed that most melanomas of the iris, ciliary body, and choroid could be treated with plaque brachytherapy. The ABS-OOTF reached consensus that tumors with gross orbital extension and blind painful eyes and those with no light perception vision are unsuitable for brachytherapy. In contrast, only select retinoblastomas are eligible for plaque brachytherapy. Prescription doses, dose rates, treatment durations, and clinical methods are described.

CONCLUSIONS

Plaque brachytherapy is an effective eye and vision-sparing method to treat patients with intraocular tumors. Practitioners are encouraged to use ABS-OOTF guidelines to enhance their practice.

Proton beam radiotherapy of uveal melanoma

Proton beam radiotherapy of uveal melanoma can be administered as primary treatment, as salvage therapy for recurrent tumor, and as neoadjuvant therapy prior to surgical resection. The physical properties of proton beams make it possible to deliver high-doses of radiation to the tumor with relative sparing of adjacent tissues. This form of therapy is effective for a wider range of uveal melanoma than any other modality, providing exceptionally-high rates of local tumor control. This is particularly the case with diffuse iris melanomas, many of which are unresectable. The chances of survival, ocular conservation, visual preservation and avoidance of iatrogenic morbidity depend greatly on the tumor size, location and extent. When treating any side-effects and/or complications, it is helpful to consider whether these are the result of collateral damage or persistence of the irradiated tumor ('toxic tumor syndrome').

Hypofractionated stereotactic photon radiotherapy of posteriorly located choroidal melanoma with five fractions at ten Gy--clinical results after six years of experience

PURPOSE

To evaluate long-term safety and efficacy of hypofractionated stereotactic photon radiotherapy with 5 five fractions at 10 Gy each in patients with centrally located choroidal melanoma.

MATERIALS AND METHODS

Ninety-one patients with centrally located choroidal melanoma were treated stereotactically at a linear accelerator with 6 MV photon beams with 5 fractions at 10 Gy each. Examinations were performed at baseline and every 3 months in the first 2 years, then every 6 months until 5 years and yearly thereafter. Median follow-up was 37.8 months (IQR 19.2-49.9). They included visual acuity assessment, routine ophthalmological examinations with fundoscopy, echography for measurement of tumor dimensions, medical examinations and, if necessary, fluorescein angiography.

RESULTS

Initial tumor base diameters, height and volume were 11.20mm (IQR 9.10-13.70), 9.80 mm (IQR 7.80-11.70), 4.53 mm (IQR 3.33-6.43) and 253.8mm(3) (IQR 127.5-477.0). Local tumor control and eye retention rates were 97.7% and 86.4% after 5 years, respectively. Eight patients developed metastatic disease and 3 of them died due to metastatic disease during the follow-up period. Median visual acuity decreased from 0.67 initially to 0.05 at the last individual follow-up (p<0.001). The most common toxicities (any grade) were radiation retinopathy (n=39), optic neuropathy (n=32), radiogenic cataract (n=21), neovascular glaucoma (n=15) and dry eye syndrome (n=10). The 5 year probabilities to remain free of these side effects (any grade) were 26.0%, 45.4%, 55.4%, 72.6% and 80.5%, respectively. The most important prognostic factors for toxicities were the largest tumor base diameter, tumor height and tumor distance to the optic disk.

CONCLUSION

Hypofractionated stereotactic photon radiotherapy with a total dose of 50 Gy delivered in 5 fractions is a highly effective treatment option in patients with centrally located choroidal melanoma and has a moderate toxicity profile.

Secondary neutron dose measurement for proton eye treatment using an eye snout with a borated neutron absorber

Background

We measured and assessed ways to reduce the secondary neutron dose from a system for proton eye treatment.

Methods

Proton beams of 60.30 MeV were delivered through an eye-treatment snout in passive scattering mode. Allyl diglycol carbonate (CR-39) etch detectors were used to measure the neutron dose in the external field at 0.00, 1.64, and 6.00 cm depths in a water phantom. Secondary neutron doses were measured and compared between those with and without a high-hydrogen–boron-containing block. In addition, the neutron energy and vertices distribution were obtained by using a Geant4 Monte Carlo simulation.

Results

The ratio of the maximum neutron dose equivalent to the proton absorbed dose (H(10)/D) at 2.00 cm from the beam field edge was 8.79 ± 1.28 mSv/Gy. The ratio of the neutron dose equivalent to the proton absorbed dose with and without a high hydrogen-boron containing block was 0.63 ± 0.06 to 1.15 ± 0.13 mSv/Gy at 2.00 cm from the edge of the field at depths of 0.00, 1.64, and 6.00 cm.

Conclusions

We found that the out-of-field secondary neutron dose in proton eye treatment with an eye snout is relatively small, and it can be further reduced by installing a borated neutron absorbing material.

[Choroidal melanoma treated by protontherapy: anatomical and functional results at Strasbourg University Medical Center]

PURPOSE

To report anatomical and functional results of choroidal melanoma treated by protontherapy between 2001 and 2011 and to compare these with data reported in the literature.

METHODS

The present study is a retrospective review of the charts of patients presenting with choroidal melanoma, managed at Strasbourg University Medical Center between 2001 and 2011, and receiving protontherapy. Visual acuity and a complete ophthalmologic examination, including intraocular pressure, dilated fundus exam, and ultrasonography with measurement of the major diameter of the tumor, were performed prior to treatment and at various follow-up visits (every six months for five years, then once a year for ten years). The rates and timing of local complications (cataract, rubeosis, retinal detachment, neovascular glaucoma and secondary enucleation) and systemic complications (metastasis) are also reported.

RESULTS

Seventy charts were included. Mean age of the treated population was 61.4 ± 15.2 years. Male/female ratio was 1.06. Mean visual acuity, 0.55 ± 0.6 (20/67) on presentation, decreased progressively from month 42. Mean tumor thickness was 5.8 ± 2.8mm and major diameter 11.2 ± 2.9 mm. Decreased tumor thickness was noted beginning at month 12 of follow-up (Anova, P<0.0001), while major diameter remained unchanged over time (P>0.05). The risk of complications (retinal detachment, rubeosis, neovascular glaucoma) was greater between the second and third year. Mean 5-year survival was 87.5%. The rate of secondary enucleation was 8.5%.

CONCLUSION

Protontherapy most often allows for preservation of the globe. Visual loss, often significant and permanent, is frequent.

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.

Dosimetry of (125)I and (103)Pd COMS eye plaques for intraocular tumors: report of Task Group 129 by the AAPM and ABS

Dosimetry of eye plaques for ocular tumors presents unique challenges in brachytherapy. The challenges in accurate dosimetry are in part related to the steep dose gradient in the tumor and critical structures that are within millimeters of radioactive sources. In most clinical applications, calculations of dose distributions around eye plaques assume a homogenous water medium and full scatter conditions. Recent Monte Carlo (MC)-based eye-plaque dosimetry simulations have demonstrated that the perturbation effects of heterogeneous materials in eye plaques, including the gold-alloy backing and Silastic insert, can be calculated with reasonable accuracy. Even additional levels of complexity introduced through the use of gold foil "seed-guides" and custom-designed plaques can be calculated accurately using modern MC techniques. Simulations accounting for the aforementioned complexities indicate dose discrepancies exceeding a factor of ten to selected critical structures compared to conventional dose calculations. Task Group 129 was formed to review the literature; re-examine the current dosimetry calculation formalism; and make recommendations for eye-plaque dosimetry, including evaluation of brachytherapy source dosimetry parameters and heterogeneity correction factors. A literature review identified modern assessments of dose calculations for Collaborative Ocular Melanoma Study (COMS) design plaques, including MC analyses and an intercomparison of treatment planning systems (TPS) detailing differences between homogeneous and heterogeneous plaque calculations using the American Association of Physicists in Medicine (AAPM) TG-43U1 brachytherapy dosimetry formalism and MC techniques. This review identified that a commonly used prescription dose of 85 Gy at 5 mm depth in homogeneous medium delivers about 75 Gy and 69 Gy at the same 5 mm depth for specific (125)I and (103)Pd sources, respectively, when accounting for COMS plaque heterogeneities. Thus, the adoption of heterogeneous dose calculation methods in clinical practice would result in dose differences >10% and warrant a careful evaluation of the corresponding changes in prescription doses. Doses to normal ocular structures vary with choice of radionuclide, plaque location, and prescription depth, such that further dosimetric evaluations of the adoption of MC-based dosimetry methods are needed. The AAPM and American Brachytherapy Society (ABS) recommend that clinical medical physicists should make concurrent estimates of heterogeneity-corrected delivered dose using the information in this report's tables to prepare for brachytherapy TPS that can account for material heterogeneities and for a transition to heterogeneity-corrected prescriptive goals. It is recommended that brachytherapy TPS vendors include material heterogeneity corrections in their systems and take steps to integrate planned plaque localization and image guidance. In the interim, before the availability of commercial MC-based brachytherapy TPS, it is recommended that clinical medical physicists use the line-source approximation in homogeneous water medium and the 2D AAPM TG-43U1 dosimetry formalism and brachytherapy source dosimetry parameter datasets for treatment planning calculations. Furthermore, this report includes quality management program recommendations for eye-plaque brachytherapy.