Design and methods of a clinical trial for a rare condition: the Collaborative Ocular Melanoma Study. COMS Report No. 3

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

PURPOSE

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

METHODS AND MATERIALS

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

RESULTS

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

CONCLUSIONS

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

AAPM Task Group Report 267: A joint AAPM GEC-ESTRO report on biophysical models and tools for the planning and evaluation of brachytherapy

Brachytherapy utilizes a multitude of radioactive sources and treatment techniques that often exhibit widely different spatial and temporal dose delivery patterns. Biophysical models, capable of modeling the key interacting effects of dose delivery patterns with the underlying cellular processes of the irradiated tissues, can be a potentially useful tool for elucidating the radiobiological effects of complex brachytherapy dose delivery patterns and for comparing their relative clinical effectiveness. While the biophysical models have been used largely in research settings by experts, it has also been used increasingly by clinical medical physicists over the last two decades. A good understanding of the potentials and limitations of the biophysical models and their intended use is critically important in the widespread use of these models. To facilitate meaningful and consistent use of biophysical models in brachytherapy, Task Group 267 (TG-267) was formed jointly with the American Association of Physics in Medicine (AAPM) and The Groupe Européen de Curiethérapie and the European Society for Radiotherapy & Oncology (GEC-ESTRO) to review the existing biophysical models, model parameters, and their use in selected brachytherapy modalities and to develop practice guidelines for clinical medical physicists regarding the selection, use, and interpretation of biophysical models. The report provides an overview of the clinical background and the rationale for the development of biophysical models in radiation oncology and, particularly, in brachytherapy; a summary of the results of literature review of the existing biophysical models that have been used in brachytherapy; a focused discussion of the applications of relevant biophysical models for five selected brachytherapy modalities; and the task group recommendations on the use, reporting, and implementation of biophysical models for brachytherapy treatment planning and evaluation. The report concludes with discussions on the challenges and opportunities in using biophysical models for brachytherapy and with an outlook for future developments.

Equivalent uniform RBE-weighted dose in eye plaque brachytherapy

BACKGROUND

Brachytherapy for ocular melanoma is based on the application of eye plaques with different spatial dose nonuniformity, time-dependent dose rates and relative biological effectiveness (RBE).

PURPOSE

We propose a parameter called the equivalent uniform RBE-weighted dose (EUDRBE) that can be used for quantitative characterization of integrated cell survival in radiotherapy modalities with the variable RBE, dose nonuniformity and dose rate. The EUDRBE is applied to brachytherapy with 125I eye plaques designed by the Collaborative Ocular Melanoma Study (COMS).

METHODS

The EUDRBE is defined as the uniform dose distribution with RBE = 1 that causes equal cell survival for a given nonuniform dose distribution with the variable RBE > 1. The EUDRBE can be used for comparison of cell survival for nonuniform dose distributions with different RBE, because they are compared to the reference dose with RBE = 1. The EUDRBE is applied to brachytherapy with 125I COMS eye plaques that are characterized by a steep dose gradient in tumor base-apex direction, protracted irradiation during time intervals of 3-8 days, and variable dose-rate dependent RBE with a maximum of about 1.4. The simulations are based on dose of 85 Gy prescribed to the farthest intraocular extent of the tumor (tumor apex). To compute the EUDRBE in eye plaque brachytherapy and correct for protracted irradiation, the distributions of physical dose have been converted to non-uniform distributions of biologically effective dose (BED) to include the biological effects of sublethal cellular repair, Our radiobiological analysis considers the combined effects of different time-dependent dose rates, spatial dose non-uniformity, dose fractionation and different RBE and can be used to derive optimized dose regimens brachytherapy.

RESULTS

Our simulations show that the EUDRBE increases with the prescription depths and the maximum increase may achieve 6% for the tumor height of 12 mm. This effect stems from a steep dose gradient within the tumor that increases with the prescription depth. The simulations also show that the EUDRBE increase may achieve 12% with increasing the dose rate when implant duration decreases. The combined effect of dose nonuniformity and dose rate may change the EUDRBE up to 18% for the same dose prescription of 85 Gy to tumor apex. The absolute dose range of 48-61 Gy (RBE) for the EUDRBE computed using 4 or 5 fractions is comparable to the dose prescriptions used in stereotactic body radiation therapy (SBRT) with megavoltage X-rays (RBE = 1) for different cancers. The tumor control probabilities in SBRT and eye plaque brachytherapy are very similar at the level of 80% or higher that support the hypothesis that the selected approximations for the EUDRBE are valid.

CONCLUSIONS

The computed range of the EUDRBE in 125I COMS eye plaque brachytherapy suggests that the selected models and hypotheses are acceptable. The EUDRBE can be useful for analysis of treatment outcomes and comparison of different dose regimens in eye plaque brachytherapy.

Uveal melanoma in the Iranian population: two decades of patient management in a tertiary eye center

BACKGROUND

To assess the characteristics and outcomes of uveal melanoma management at a tertiary center in the Middle East.

METHODS

A study on 164 patients with uveal melanoma was conducted by reviewing the available medical records, ultrasound, and pathology report results. Age at diagnosis, tumor location and size, treatment mode, visual outcome, metastasis, mortality, and survival were studied.

RESULTS

The mean age of patients was 52.0 ± 15.0 years, and 52.5% were male. Choroidal melanoma was the most common uveal melanoma, followed by the ciliary body and iris melanoma. The mean thickness of tumors was 8.29 ± 3.29. The majority of patients (n = 111, 67.9%) were managed by brachytherapy with ruthenium-106 plaques. Enucleation was performed primarily in 46 (28%) patients and secondarily in nine (5.5%) patients. The sexual disparity was detected as the proximity of uveal melanoma to the fovea in males. For a 61-month mean follow-up period, mortality occurred in eight of our cases, six of which were due to metastasis. The most common site for distance metastasis was the liver (5/6), followed by the lung (1/6). The five-year and eight-year overall survival (OS) rate was 0.947%± 0.019. The 5-year survival rate reached zero in metastatic patients. OS was not statistically different depending on the age, tumor diameters, the primary treatment received, or the histopathologic findings (p > 0.50 for all).

CONCLUSION

In this study, individuals diagnosed with UM exhibited an OS rate of around 94% at the five-year mark, which remained consistent up to eight years. Notably, the presence of distance metastasis emerged as the sole statistically significant factor influencing overall survival.

Uveal melanoma in African Americans: Diagnostic challenges

Uveal melanoma (UM) is uncommon in African Americans. Owing to its rarity, UM may not be suspected in African Americans leading to delayed diagnosis. In addition, socioeconomic factors may also play a role in delayed diagnosis. Clinical and ultrasonographic features may be atypical due to racial pigmentation, necessitating diagnostic fine needle aspiration biopsy. Herein, we report an illustrative case series of 12 African Americans with UM highlighting clinical features and diagnostic challenges.

MR-based follow-up after brachytherapy and proton beam therapy in uveal melanoma

PURPOSE

MRI is increasingly used in the diagnosis and therapy planning of uveal melanoma (UM). In this prospective cohort study, we assessed the radiological characteristics, in terms of anatomical and functional imaging, of UM after ruthenium-106 plaque brachytherapy or proton beam therapy (PBT) and compared them to conventional ultrasound.

METHODS

Twenty-six UM patients were evaluated before and 3, 6 and 12 months after brachytherapy (n = 13) or PBT (n = 13). Tumour prominences were compared between ultrasound and MRI. On diffusion-weighted imaging, the apparent diffusion value (ADC), and on perfusion-weighted imaging (PWI), the time-intensity curves (TIC), relative peak intensity and outflow percentages were determined. Values were compared between treatments and with baseline.

RESULTS

Pre-treatment prominences were comparable between MRI and ultrasound (mean absolute difference 0.51 mm, p = 0.46), but larger differences were observed post-treatment (e.g. 3 months: 0.9 mm (p = 0.02)). Pre-treatment PWI metrics were comparable between treatment groups. After treatment, brachytherapy patients showed favourable changes on PWI (e.g. 67% outflow reduction at 3 months, p < 0.01). After PBT, significant perfusion changes were observed at a later timepoint (e.g. 38% outflow reduction at 6 months, p = 0.01). No consistent ADC changes were observed after either treatment, e.g. a 0.11 × 10^-3mm²/s increase 12 months after treatment (p = 0.15).

CONCLUSION

MR-based follow-up is valuable for PBT-treated patients as favourable perfusion changes, including a reduction in outflow, can be detected before a reduction in size is apparent on ultrasound. For brachytherapy, a follow-up MRI is of less value as already 3 months post-treatment a significant size reduction can be measured on ultrasound.

Transitioning from a COMS-based plaque brachytherapy program to using eye physics plaques and plaque simulator treatment planning system: A single institutional experience

The aim of this work is to describe the implementation and commissioning of a plaque brachytherapy program using Eye Physics eye plaques and Plaque Simulator treatment planning system based on the experience of one institution with an established COMS-based plaque program. Although commissioning recommendations are available in official task groups publications such as TG-129 and TG-221, we found that there was a lack of published experiences with the specific details of such a transition and the practical application of the commissioning guidelines. The specific issues addressed in this paper include discussing the lack of FDA approval of the Eye Physics plaques and Plaque Simulator treatment planning system, the commissioning of the plaques and treatment planning system including considerations of the heterogeneity corrected calculations, and the implementation of a second check using an FDA-approved treatment planning system. We have also discussed the use of rental plaques, the analysis of plans using dose histograms, and the development of a quality management program. By sharing our experiences with the commissioning of this program this document will assist other institutions with the same task and act as a supplement to the recommendations in the recently published TG-221.

Radio-luminescent imaging for rapid, high-resolution eye plaque loading verification

BACKGROUND

Eye plaque brachytherapy is currently an optimal therapy for intraocular cancers. Due to the lack of an effective and practical technique to measure the seed radioactivity distribution, current quality assurance (QA) practice according to the American Association of Physicists in Medicine TG129 only stipulates that the plaque assembly be visually inspected. Consequently, uniform seed activity is routinely adopted to avoid possible loading mistakes of differential seed loading. However, modulated dose delivery, which represents a general trend in radiotherapy to provide more personalized treatment for a given tumor and patient, requires differential activities in the loaded seeds.

PURPOSE

In this study, a fast and low-cost radio-luminescent imaging and dose calculating system to verify the seed activity distribution for differential loading was developed.

METHODS

A proof-of-concept system consisting of a thin scintillator sheet coupled to a camera/lens system was constructed. A seed-loaded plaque can be placed directly on the scintillator surface with the radioactive seeds facing the scintillator. The camera system collects the radioluminescent signal generated by the scintillator on its opposite side. The predicted dose distribution in the scintillator's sensitive layer was calculated using a Monte Carlo simulation with the planned plaque loading pattern of I-125 seeds. Quantitative comparisons of the distribution of relative measured signal intensity and that of the relative predicted dose in the sensitive layer were performed by gamma analysis, similar to intensity-modulated radiation therapy QA.

RESULTS

Data analyses showed high gamma (3%/0.3 mm, global, 20% threshold) passing rates for correct seed loadings and low passing rates with distinguished high gamma value area for incorrect loadings, indicating that possible errors may be detected. The measurement and analysis only required a few extra minutes, significantly shorter than the time to assay the extra verification seeds the physicist already must perform as recommended by TG129.

CONCLUSIONS

Radio-luminescent QA can be used to facilitate and assure the implementation of intensity-modulated, customized plaque loading.

Predicted vs Observed Metastasis-Free Survival in Individuals With Uveal Melanoma

Importance

Accuracy of the predicted metastasis-free survival (MFS) by a commercially available gene expression profiling (GEP) test is not known.

Objective

To compare the predicted MFS with the observed MFS in patients in this cohort and with those in published studies (published MFS, meta-analysis).

Design, Setting, and Participants

This cohort study included consecutive patients from the University of Iowa and Cleveland Clinic who were diagnosed with uveal melanoma who underwent prognostic fine-needle aspiration biopsy at the time of primary treatment. Patients were recruited from December 2012 to December 2020. The predicted MFS for patients was extracted from the GEP report. The observed MFS was defined as time to metastasis. Cox proportional hazards models were fit to identify tumor variables impacting MFS in patients with class 2 tumors. The overall estimate of the published MFS was obtained by performing meta-analysis of data from published series. Analysis took place in August 2021.

Main Outcomes and Measures

MFS.

Results

There were 92 patients from the University of Iowa and 255 patients from the Cleveland Clinic. The mean (SD) age at diagnosis was 59.4 (13.0) years. The median (IQR) follow-up interval was 38.0 (19.0-57.0) months. The observed MFS for patients with class 2 tumor in this cohort (3 years: 67% [95% CI, 59%-77%]; 5 years: 47% [95% CI, 37%-61%]) and in published studies (3 years: 62% [95% CI, 57%-66%]; 5 years: 40% [95% CI, 34%-46%]) were better than those predicted (50% and 28% for 3 and 5 years, respectively). Within patients with class 2 tumor, those with metastasis had larger tumors compared with nonmetastatic tumors (mean largest basal diameter difference, 1.7 [95% CI, 0.5-3.0] mm; P = .01; mean thickness ratio, 1.3 [95% CI, 1.04-1.5]; P = .01, respectively). An increasing tumor size was significantly associated with increased hazard ratio (1.16 [95% CI, 1.06-1.27]; P < .001) of metastasis.

Conclusions and Relevance

These findings suggest the predicted MFS for metastatic tumors (class 2) appears to be worse than that observed here and reported by others. Incorporation of tumor size in the prediction model may enhance its accuracy. Adjuvant therapy trials may not be able to rely on predicted MFS to calculate efficacy with a high degree of confidence.

Analysis of dose to the macula, optic disc, and lens in relation to vision toxicities - A retrospective study using COMS eye plaques

PURPOSE

The aim of this study was to relate common toxicity endpoints with dose to the macula, optic disc, and lens for uveal melanoma patients treated with Iodine-125 Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy.

METHODS

A cohort of 52 patients treated at a single institution between 2005 and 2019 were retrospectively reviewed. Demographics, dosimetry, and clinical outcomes were recorded. Univariate, relative risk, and Kaplan-Meier analyses were performed to relate dose to toxicity endpoints including retinopathy, vision decline, and cataracts.

RESULTS

By the end of follow up (Median = 3.6 years, Range = 0.4 - 13.5 years), 65 % of eyes sustained radiation retinopathy, 40 % demonstrated moderate vision decline (>5 Snellen lines lost), and 56 % developed cataracts. Significant (p < 0.05) risk estimates exist for retinopathy and VA decline for doses >52 Gy to the macula and >42 Gy to the optic disc. Moreover, dose to the lens > 16 Gy showed a significant risk for cataract formation. Kaplan-Meier analysis demonstrated significantly different incidence of radiation retinopathy for > 52 Gy to the macula and > 42 Gy to the optic disc. In addition, the Kaplan-Meier analysis showed significantly different incidence of cataract formation for patients with lens dose > 16 Gy.

CONCLUSIONS

Dose-effect relationships exist for the macula and optic disc with respect to the loss of visual acuity and the development of retinopathy. To better preserve vision after treatment, further research is needed to reduce macula, optic disc, and lens doses while maintaining tumor control.

Retrospective analysis of secondary enucleation for uveal melanoma after plaque radiotherapy

Background

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Plaque brachytherapy (PRT) is widely accepted as an effective globe-conserving treatment modality for UM. However, local treatment failure and complications lead to the enucleation of irradiated eyes. We conducted this study to explore the causes and long-term prognosis for UM patients who accepted secondary enucleation after plaque radiotherapy.

Methods

This was a retrospective cohort study. Data of patients who underwent secondary enucleation for UM after plaque radiotherapy, from July 2007 to July 2019, at Beijing Tongren Hospital were analyzed. Kaplan–Meier analysis was performed to assess the probability of indications, metastasis, and metastasis-related death. Cox regression analysis was used to analyze associations of the prognostic factors.

Results

Eight hundred and eighty patients were clinically diagnosed with uveal melanoma and initially treated by iodine-125 plaque radiotherapy, 132 of whom underwent secondary enucleation and pathological examination in the same hospital. Fifty-two (39.4%) eyes were enucleated simply because of uncontrollable neovascular glaucoma (NVG). Forty-four (33.3%) patients suffered from tumor recurrence. Tumor non-response occurred in 18 (13.6%) cases. Ten (7.6%) eyes received enucleation entirely due to other types of glaucoma. Failure to preserve the eyes for other reasons occurred in eight (6.1%) patients. At a median follow-up of 58.1 [IQR: 40.9–90.5] months, the systemic spread was detected in 45 (34.1%) patients, and 38 of them died. On multivariate analysis, tumor largest basal diameter (HR 1.15 [95% CI: 1.01, 1.31]), tumor non-response (HR 7.22 [95% CI: 2.63, 19.82]), and recurrence (HR 3.29 [95% CI: 1.54, 7.07]) were risk factors for metastasis. Increased age (HR 1.54 [95% CI: 1.07, 2.23]), tumor non-response (HR 7.91 [95% CI: 2.79, 22.48]), and recurrence (HR 3.08 [95% CI: 1.13, 7.23]) were risk factors for metastasis-related death.

Conclusions

NVG was the major reason for secondary enucleation for Chinese UM patients after PRT. Tumor non-response and recurrence were associated with a significantly higher risk of long-term metastasis and metastasis-related death.

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.

Metastatic uveal melanoma: The final frontier

Treatment of primary intraocular uveal melanoma has developed considerably, its driver genes are largely unraveled, and the ways to assess its risk for metastases are very precise, being based on an international staging system and genetic data. Unfortunately, the risk of distant metastases, which emerge in approximately one half of all patients, is unaltered. Metastases are the leading single cause of death after uveal melanoma is diagnosed, yet no consensus exists regarding surveillance, staging, and treatment of disseminated disease, and survival has not improved until recently. The final frontier in conquering uveal melanoma lies in solving these issues to cure metastatic disease. Most studies on metastatic uveal melanoma are small, uncontrolled, retrospective, and do not report staging. Meta-analyses confirm a median overall survival of 10-13 months, and a cure rate that approaches nil, although survival exceeding 5 years is possible, estimated 2% either with first-line treatment or with best supportive care. Hepatic ultrasonography and magnetic resonance imaging as surveillance methods have a sensitivity of 95-100% and 83-100%, respectively, to detect metastases without radiation hazard according to prevailing evidence, but computed tomography is necessary for staging. No blood-based tests additional to liver function tests are generally accepted. Three validated staging systems predict, each in defined situations, overall survival after metastasis. Their essential components include measures of tumor burden, liver function, and performance status or metastasis free interval. Age and gender may additionally influence survival. Exceptional mutational events in metastases may make them susceptible to checkpoint inhibitors. In a large meta-analysis, surgical treatment was associated with 6 months longer median overall survival as compared to conventional chemotherapy and, recently, tebentafusp as first-line treatment at the first interim analysis of a randomized phase III trial likewise provided a 6 months longer median overall survival compared to investigator's choice, mostly pembrolizumab; these treatments currently apply to selected patients. Promoting dormancy of micrometastases, harmonizing surveillance protocols, promoting staging, identifying predictive factors, initiating controlled clinical trials, and standardizing reporting will be critical steppingstones in reaching the final frontier of curing metastatic uveal melanoma.

Radiobiological evaluation of organs at risk for electronic high-dose-rate brachytherapy in uveal melanoma: a radiobiological modeling study

Purpose

The objective of this study was to examine feasibility of single- or hypo-fraction of high-dose-rate (HDR) electronic brachytherapy (eBT) in uveal melanoma treatment.

Material and methods

Biologically effective doses (BED) of organs at risk (OARs) were compared to those of iodine-125-based eye plaque low-dose-rate brachytherapy (¹²⁵I LDR-BT) with vitreous replacement (VR). Single- or hypo-fractionated equivalent physical doses (SFEDs or HFEDs) for tumor were calculated from tumor BED of ¹²⁵I LDR-BT using linear-quadratic (LQ) and universal survival curve (USC) models. BED OARs doses to retina opposite the implant, macula, optic disc, and lens were calculated and compared among SFED, HFED, and ¹²⁵I LDR-BT. Electronic BT of 50 kVp was considered assuming dose fall-off as clinically equivalent to ¹²⁵I LDR-BT. All OARs BEDs were analyzed with and without silicone oil VR.

Results

For a single-fraction incorporating VR, the median/interquartile range of LQ (USC)-based BED doses of the retina opposite the implant, macula, optic disc, and lens were 16%/1.2% (33%/4%), 35%/19.5% (64%/17.7%), 37%/19% (75%/17.8%), and 27%/7.9% (68%/23.2%) of those for ¹²⁵I LDR-BT, respectively. SFED tumor values were 29.8/0.2 Gy and 51.7/0.5 Gy when using LQ and USC models, respectively, which could be delivered within 1 hour. SFED can be delivered within 1 hour using a high-dose-rate eBT. Even four-fraction delivery of HFED without VR resulted in higher OARs doses in the macula, optic disc, and lens (135 ~ 159%) than when using ¹²⁵I LDR-BT technique. A maximum p-value of 0.005 was observed for these distributions.

Conclusions

The simulation of single-fraction eBT, including vitreous replacement, resulted in significantly reduced OARs doses (16 ~ 75%) of that achieved with ¹²⁵I LDR-BT.

Radiation Retinopathy: Detection and Management Strategies

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

Outcomes for posterior uveal melanoma: Validation of American Brachytherapy Society Guidelines

PURPOSE

To assess outcomes of small and medium choroidal melanoma (less than 5.0 mm in height) following Iodine-125 episcleral brachytherapy.

METHODS AND MATERIALS

Patients with small and medium choroidal melanoma that underwent Iodine-125 brachytherapy with apical height of 1.0 mm to 5.0 mm and largest basal diameter of ≤16.0 mm were included. Data were extracted from the original dosimetry plans to determine doses to vision critical structures with the prescription point to the apical height (actual dose, ABS guidelines) and, after simulation, with the prescription point to the height of 5.0 mm (simulated dose, COMS protocol). Visual acuity (VA) outcomes with actual dose and that predicted with the simulated dose were estimated along with local recurrence, ocular survival, and survival at 5 years.

RESULTS

A total of 339 patients with a mean age of 61.5 years with a mean follow up duration of 43.4 months were included. The mean dose reduction for lens, optic disc, and fovea was 34%, 39.4%, and 41.4%, respectively with actual dose when compared with simulated dose. The Kaplan-Meier estimations for 3 year event free rate of VA of 20/50 or better were 56% and 31% for actual dose and simulated dose, respectively. Only 3 events of local recurrence were observed (enucleated) yielding 5 year local control and ocular survival rate of 98%. Overall survival (OS) and metastasis free survival (MFS) were 95% and 87.5% at 5 years, respectively.

CONCLUSIONS

Small and medium choroidal melanoma treated according to ABS has excellent outcomes. Brachytherapy planning using ABS guidelines as compared to COMS protocol may be associated with lower rates of radiation toxicity and vision loss.

Electronic charting of radiation therapy planning and treatment: Report of Task Group 262

While most Radiation Oncology clinics have adopted electronic charting in one form or another, no consensus document exists that provides guidelines for safe and effective use of the Radiation Oncology electronic medical records (RO-EMR). Task Group 262 was formed to provide these guidelines as well as to provide recommendations to vendors for improving electronic charting functionality in future. Guidelines are provided in the following areas: Implementation and training for the RO-EMR, acceptance testing and quality assurance (QA) of the RO-EMR, use of the RO-EMR as an information repository, use of the RO-EMR as a workflow manager, electronic charting for brachytherapy and nonstandard treatments, and information technology (IT) considerations associated with the RO-EMR. The report was based on a literature search by the task group, an extensive survey of task group members on their respective RO-EMR practices, an AAPM membership survey on electronic charting, as well as group consensus.

Intra-operative ocular ultrasonography of iodine-125 brachytherapy plaques in patients with uveal melanoma

Purpose

Brachytherapy with iodine-125 (¹²⁵I) has been extensively used as a conservative treatment for uveal melanoma (UM). Surgical technique for correct placement of episcleral radioactive plaques (ERP) in UM cases with posterior choroidal location and/or small size can be difficult and inaccurate. In this study, the correct positioning of plaques was assessed by intra-operative ultrasound control.

Material and methods

This was a longitudinal, retrospective study of consecutive 20 patients with UM (small-medium size and/or posterior location) who received ¹²⁵I brachytherapy. Location of plaques was adjusted by intra-operative ocular ultrasonography control. To perform ocular intra-operative ultrasonography, a 10 MHz probe was used to longitudinal and transverse bases in corresponding dummy plaques.

Results

The study included 8 males and 12 females, with a mean age of 66.3 years (SD = 14.53), 5 right eyes (RE) and 15 left eyes (LE). In ultrasound examination, 4 UMs were of mushroom morphology and the rest nodular. Means of the size of UM by ultrasound were (mm): Lb: 10.60 (SD = 2.24) × Tb: 9.88 (SD = 1.54) × H: 4.02 (SD = 1.44) (3 cases corresponding to small size of collaborative ocular melanoma study (COMS), and 17 cases to medium). The plaques used were between 14 and 20 mm in diameter, with an average distance between the edge of greater base of the tumor and the edge of plate of 2.44 mm (SD = 0.34). It was necessary to surgically reposition the plaque in 4 cases (20%).

Conclusions

Intra-operative ultrasound control improves the accuracy of radioactive plaque placement for the treatment of medium-small UMs in posterior location. Probably, this technique should be applied in all cases of brachytherapy, regardless of the isotope chosen and the location of tumor mass, in order to perfectly adjust therapeutic position.

Uveal Melanoma in Asians: A Review

Despite limited data, some differences in the clinical profile can be observed in Asian population when compared with presentation of uveal melanoma (UM) in white population. The incidence of UM is higher in Whites than in Asians. For the purpose of comparison with Asian population, data from North America, Europe, and Australia were considered as that of "white" population. The annual incidence of UM has been reported to be 5-6 cases/million in whites. The incidence in different parts of Asia is estimated at 0.2-0.6 per million. The age of presentation is around 40-55 years in Asians, which is younger when compared to that of whites (mean age of 58 years). At presentation, mean basal diameter of tumors in Asians is greater compared to whites but overall, medium-size tumors are most common. Clinical presentation is straightforward in majority of cases with retinal detachment, acute glaucoma, uveitis, cataract, or vitreous hemorrhage as common symptoms. Epithelioid cell-type variant carries the worst prognosis. Management options for choroidal melanoma include transpupillary thermotherapy, plaque radiotherapy, charged particle irradiation, local resection, enucleation, or orbital exenteration. Most commonly used modalities are enucleation and plaque radiotherapy.

Experiences of two different modalities in the management of choroidal melanoma in the Asian Indian population

BACKGROUND

Choroidal malignant melanoma is a rare intraocular cancer in Asian Indian population. There is a paucity of data from our population comparing iodine 125 (I-125) brachytherapy and enucleation.

AIM

This study aims to compare two groups of choroidal melanoma patients treated with either I-125 brachytherapy or enucleation in the Asian Indian population.

OBJECTIVES

To evaluate the long-term morbidity and mortality rates in choroidal melanoma patients treated with either I-125 brachytherapy or enucleation.

METHODS

It is a retrospective study involving forty four eyes, diagnosed with choroidal melanoma from May 2008 to February 2015. All were evaluated preoperatively for metastasis. Twenty-two underwent globe salvaging I-125 brachytherapy surgery whereas remaining 22 underwent globe destructive primary enucleation procedure.

RESULTS

At a mean follow-up 39 months, 2 of 22 cases (9%) died in the brachytherapy group. One was secondary to metastasis in the liver while the other case died of a natural cause. In the enucleation group also, there were two deaths (9%) secondary to metastasis. The metastasis free survival was 95% in the brachytherapy group and 91% in the enucleation group, which was not statistically significant (P = 0.3577). Kaplan-Meier survival at 3 years and 5 years was 95% and 89% for brachytherapy group and 94% and 89% for enucleation group.

CONCLUSION

This study found no difference in the long-term survival of choroidal melanoma patients treated with either brachytherapy or enucleation in the Asian Indian eyes.

Small choroidal melanoma: outcomes following apical height dose brachytherapy

Aim

To assess the outcomes of small choroidal melanoma following iodine-125 episcleral brachytherapy (apical height dose of 85 Gy).

Methods

Patients with small choroidal melanoma that underwent iodine-125 episcleral brachytherapy between January 2004 and December 2017 were reviewed. Inclusion criterion for this study was the COMS small tumour size (tumour apical height of 1.0–2.5 mm and largest basal diameter (LBD) <16.0 mm). Patients that received any form of prior therapy or adjuvant transpupillary thermotherapy were excluded. Outcome measures were visual acuity (VA), recurrence, ocular survival and metastasis at 3 years. Kaplan-Meier estimation was calculated for VA, recurrence, ocular survival and survival outcome (overall and metastasis-free survival rate) at 3 years.

Results

161 cases of choroidal melanoma were included in this study, with the mean (SD) age of 59.6 (14.1) years, and 93 (58%) were males. The mean (SD) apical height for the tumours were 2.1 (0.4) mm and mean (SD) LBD was 8.3 (2.2) mm. The mean (SD, median) follow-up was 40.7 months (37.1, 25 months). The VA was 20/50 or better in 69%. Only one recurrence event (1%) and one enucleation event (1%) were observed. Overall survival was 97%, and no metastatic events were observed at 3 years.

Conclusion

Small choroidal melanomas treated with iodine-125 episcleral brachytherapy have excellent outcomes. The majority (69%) of patients retained VA of 20/50 or better with very high local control and ocular survival rate (99.3%) with the absence of metastasis (100%).

AAPM recommendations on medical physics practices for ocular plaque brachytherapy: Report of task group 221

The American Association of Physicists in Medicine (AAPM) formed Task Group 221 (TG-221) to discuss a generalized commissioning process, quality management considerations, and clinical physics practice standards for ocular plaque brachytherapy. The purpose of this report is also, in part, to aid the clinician to implement recommendations of the AAPM TG-129 report, which placed emphasis on dosimetric considerations for ocular brachytherapy applicators used in the Collaborative Ocular Melanoma Study (COMS). This report is intended to assist medical physicists in establishing a new ocular brachytherapy program and, for existing programs, in reviewing and updating clinical practices. The report scope includes photon- and beta-emitting sources and source:applicator combinations. Dosimetric studies for photon and beta sources are reviewed to summarize the salient issues and provide references for additional study. The components of an ocular plaque brachytherapy quality management program are discussed, including radiation safety considerations, source calibration methodology, applicator commissioning, imaging quality assurance tests for treatment planning, treatment planning strategies, and treatment planning system commissioning. Finally, specific guidelines for commissioning an ocular plaque brachytherapy program, clinical physics practice standards in ocular plaque brachytherapy, and other areas reflecting the need for specialized treatment planning systems, measurement phantoms, and detectors (among other topics) to support the clinical practice of ocular brachytherapy are presented. Expected future advances and developments for ocular brachytherapy are discussed.

CORRELATION OF GENE EXPRESSION PROFILE STATUS AND AMERICAN JOINT COMMISSION ON CANCER STAGE IN UVEAL MELANOMA

PURPOSE

To study the relationship between gene expression profile (GEP) subclass and American Joint Committee on Cancer (AJCC) stage in patients with uveal melanoma (UM).

METHODS

A retrospective, multicenter study was undertaken with patients entered from nine major ocular oncology centers from across the United States. Three hundred sixty eligible patients had UM and underwent I-125 plaque brachytherapy with concurrent tumor biopsy with GEP testing between January 1, 2010, and October 28, 2014. Patient demographics and UM features were analyzed by both GEP and AJCC status.

RESULTS

Gene expression profile class divided the cohort into three groups: Class 1a (n = 186), Class 1b (n = 77), and Class 2 (n = 113). When classified using AJCC staging criteria, we found the following: Stage I in 91 cases (25.3%), Stage IIA in 143 cases (39.7%), Stage IIB in 89 cases (24.7%), Stage IIIA in 36 cases (10%), and Stage IIIB in 1 case (0.3%). There were no Stage IV cases, as lymph node and metastatic data were not collected as a part of this study. Among Stage I tumors, both high tumor height and high largest basal diameter were associated with a higher frequency of Class 2 status (P < 0.05). As UMs progress to a larger AJCC tumor group (T1-T4), the odds ratio of having a worse prognosis based on GEP class was 1.75 (95% CI, 1.36-2.25; P < 0.001). Similarly, as UMs progress to a higher AJCC stage, the odds ratio of having a worse prognosis based on GEP class was 1.69 (95% CI, 1.36-2.10; P < 0.001).

CONCLUSION

This report details the differences in clinical features between GEP subclasses and how they are distributed among the AJCC stages. When the tumors were grouped by AJCC staging criteria, both larger AJCC tumor (T) group and worsening AJCC stage were associated with worsening predicted prognosis, based on GEP subclass.

Gene Expression Profiling Prognostication of Posterior Uveal Melanoma: Does Size Matter?

PURPOSE

Investigate the influence of tumor size by American Joint Committee on Cancer (AJCC) stage, Collaborative Ocular Melanoma Study (COMS) size, tumor largest basal diameter (LBD), and tumor thickness on prognostication by gene expression profiling (GEP) class.

DESIGN

Two-center retrospective study.

PARTICIPANTS

Two hundred fifteen consecutive patients diagnosed with posterior uveal melanoma over a 5-year period who were evaluated with prognostic fine-needle aspiration biopsy at the time of primary treatment.

METHODS

Patient demographics, tumor clinical size, AJCC stage, COMS size, GEP class, presence of metastasis, and mortality data were collected. Metastasis-free-survival (MFS) was defined as time to metastasis or death from any cause. Comparisons were made using Pearson chi-square tests or Fisher exact tests for categorical factors, and t tests or Kruskal-Wallis tests for continuous measures. Cox proportional hazards models were fit to identify whether size measurements increased the prognostic discrimination index (C-statistic).

MAIN OUTCOME MEASURES

Metastasis-free-survival.

RESULTS

The average follow-up interval was 22.0 months (range, 12.0-37.0 months). Eighty-nine tumors were class 1A, 48 class 1B, and 78 class 2. Twenty-one patients developed metastatic disease detected by surveillance and confirmed by liver biopsy. Three-year MFS was 96% for class 1 and 63% for class 2. Five-year MFS was 96% for class 1 and 49% for class 2. All size measures significantly improved prognostic discrimination index by GEP class, as shown by increase in the C-statistic with addition of size variables (C-statistic 0.750 GEP alone, 0.830 GEP with AJCC [P = 0.016], 0.822 GEP with COMS [P < 0.001], 0.842 GEP with LBD [P <0.001], and 0.847 GEP with tumor thickness [P < 0.001]). Class 2 patients with metastasis had larger tumors compared with nonmetastatic class 2 tumors (AJCC class, P = 0.004; COMS class, P = 0.024; with metastasis mean thickness 6.5 mm [interquartile range (IQR), 3.8-9.5 mm]; without metastasis, 3.9 mm [SD, 3.1-6.0 mm]; P = 0.008), with metastasis mean LBD 14.9±2.8 mm, without metastasis, 12.3±2.7 mm (P < 0.001). All class 1 tumors with metastasis were large and required enucleation.

CONCLUSIONS

Incorporation of tumor size enhances the prognostic discrimination index of the GEP test in patients with posterior uveal melanoma. All size tumor parameters are equivalent in their ability to enhance GEP prognostication.

Practice Patterns for the Treatment of Uveal Melanoma with Iodine-125 Plaque Brachytherapy: Ocular Oncology Study Consortium Report 5

Background

Treatment planning for I-125 plaque therapy for uveal melanoma has advanced significantly since the Collaborative Ocular Melanoma Study trial, with more widely available image-guided planning and improved dosimetry.

Objective

We evaluated real-world practice patterns for I-125 plaque brachytherapy in the United States by studying practice patterns at centers that comprise the Ocular Oncology Study Consortium (OOSC).

Methods

The OOSC database and responses to a treatment practice survey were evaluated. The database contains treatment information from 9 institutions. Patients included in the database were treated between 2010 and 2014. The survey was conducted in 2018 and current treatment planning methods and prescriptions were queried.

Results

Examination of the OOSC database revealed that average doses to critical structures were highly consistent, with the exception of one institution. Survey responses indicated that most centers followed published guidelines regarding dose and prescription point. Dose rate ranged from 51 to 118 cGy/h. As of 2018, most institutions use pre-loaded plaques and fundus photographs and/or computed tomography or magnetic resonance imaging in planning.

Conclusions

While there were differences in dosimetric practices, overall agreement in plaque brachytherapy practices was high among OOSC institutions. Clinical margins and planning systems were similar among institutions, while prescription dose, dose rates, and dosimetry varied.

Silicone Oil and Iodine-125 Brachytherapy for Uveal Melanoma in High-Risk Patients

Purpose

Silicone oil a burgeoning adjuvant in the treatment of uveal melanoma where it is used for tissue protection during I-125 brachytherapy. While risk factors in the development of radiation retinopathy (RR) have been identified, treatment modulation for high-risk patients has largely been overlooked. We seek to expand the literature on this subject by reporting outcomes of I-125 brachytherapy with silicone oil in a high-risk population in the community setting.

Methods

Five patients with uveal melanoma and at least one risk factor for RR development underwent iodine-125 (I-125) plaque brachytherapy with concurrent pars plana vitrectomy (PPV), silicone oil administration, and fine needle aspiration biopsy (FNAB). Plaque and silicone oil removal were performed after seven days. Minimum follow-up was 12 months.

Results

Follow-up ranged from 12 to 56 months. Macular radiation doses ranged from 12.55 to 141.5 Gy; the two eyes with the largest doses developed RR at 34 and 15 months as well as neovascular glaucoma (NVG). Surgical complications included one rhegmatogenous retinal detachment (RD) and an intra-operative vitreous hemorrhage with post-operative hyphema requiring additional intervention.

Conclusion

RR may be attenuated by silicone oil administration in patients with some risk factors. In tumors farther from the macula, this benefit is more readily apparent. Tumors located more posteriorly may not benefit from silicone oil administration considering postoperative complications and operating time. Patient demographics, tumor characteristics, and anticipated macular radiation dosage may help determine which patients can benefit from silicone oil and identify patient risks for adverse outcomes.

Clinical spectrum, treatment and outcomes of uveal melanoma in a tertiary centre

INTRODUCTION

We aimed to describe the clinical characteristics, diagnostic challenges, treatment patterns and outcomes of uveal melanoma (UM) in a tertiary care centre.

METHODS

This is a retrospective case series of 11 consecutive patients with UM who were managed in a tertiary referral centre between 2002 and 2017. Epidemiological, clinical, pathological and radiological characteristics were reviewed. Classification of choroidal melanoma as small, medium or large was based on the criteria established by the Collaborative Ocular Melanoma Study.

RESULTS

Mean age at presentation was 42.9 (range 27‒67) years. In 7 (64%) patients, a definitive diagnosis of UM was made after a mean follow-up period of 6.4 (range 1‒17) months. There were one, six and four patients with small-, medium- and large-sized choroidal melanomas, respectively. Treatment was enucleation in 5 (45.5%) patients, plaque brachytherapy in 4 (36.4%) patients, transpupillary thermotherapy in 1 (9.1%) patient, and observation in 1 (9.1%) patient. Median follow-up was 29 months. Metastatic disease developed in 5 (45.5%) patients at the mean age of 46.6 (range 38‒56) years, with median overall survival of 20 months. Genetic mutations in three patients were monosomy 3 (n = 2), and gain of 3q and 8q (n = 1).

CONCLUSION

Our study supports the finding that UM in Chinese and Asian Indian patients presents at a younger age than in Caucasians. Although it is rare, ophthalmologists should remain mindful of this life-threatening disease. We propose establishing a national and regional registry for ocular tumours with genetic information to characterise the disease spectrum in Southeast Asia.

Episcleral brachytherapy for retinoblastoma

BACKGROUND/AIMS

To report visual outcomes, survival outcomes and complications following episcleral brachytherapy (EB) for retinoblastoma.

METHODS

Retrospective review of retinoblastoma cases treated with EB in a single institution. Survival outcomes were analysed using the Kaplan-Meier method.

RESULTS

Eleven tumours of 11 eyes were treated with either iodine-125 or ruthenium-106 EB with a mean apical dose of 44 Gy. The tumours were classified as group B in 5 (46%), C in 3 (27%) or D in 3 (27%) eyes, respectively. Mean follow-up time was 75.4 months. EB served as primary treatment in 3 eyes (27%) and secondary treatment in 8 eyes (73%). Final visual acuity was better than 20/200 in 70% of cases. Globe preservation was achieved in 9 (82%) eyes. Local recurrence occurred in 18% of cases at a mean onset of 17.4 months after EB. Two group D tumours that recurred after secondary EB underwent enucleation. Mean onset of radiation retinopathy was 17.4 months following EB. No metastatic or fatal events were recorded. Kaplan-Meier analysis showed recurrence-free survival and ocular survival of 80% and overall survival of 100% at 5 years after EB.

CONCLUSION

EB is an effective primary or secondary treatment modality for selected retinoblastoma eyes (groups B and C). Advanced group D tumours may represent a risk factor for local recurrence. Visually significant complications such as radiation retinopathy should be anticipated.

Clinical predictors of survival in metastatic uveal melanoma

PURPOSE

To determine the clinical factors that influence survival in patients with metastatic uveal melanoma.

STUDY DESIGN

Single-center, retrospective review of patients' medical records.

METHODS

The following data of ninety-nine consecutive patients (49 men, 50 women) with metastatic uveal melanoma were registered: patient demographics; primary tumor characteristics; features of first melanoma-related metastasis; symptoms and patient status at distant disease debut and metastasis treatment. Overall survival was analyzed by Kaplan-Meier estimates. A Cox proportional hazards regression model was applied to identify independent predictors associated with survival.

RESULTS

Mean patient age at metastatic diagnosis was 60.7 years (standard deviation, 12.8). The liver was the first metastatic site in most (92.9%) cases. The median disease-free interval was 26 months (interquartile range, 34). Median overall survival after detection of the first metastasis was 8 months (interquartile range, 14). The baseline characteristics of the primary uveal melanoma were not associated with survival in patients with stage IV disease. In the multivariate analysis, the following factors at first metastatic diagnosis were associated with improved overall survival: disease-free interval > 36 months; better performance status; and normal serum lactate dehydrogenase and gamma glutamyl transpeptidase levels. Overall survival was not influenced by specific metastatic treatment.

CONCLUSION

Although metastatic uveal melanoma has a poor prognosis, this study reveals the existence of several independent prognostic factors for prolonged overall survival. These findings may help improve survival estimates in patients with advanced disease.

GNAQ and PMS1 Mutations Associated with Uveal Melanoma, Ocular Surface Melanosis, and Nevus of Ota

G protein mutations are common in uveal melanomas, and the vast majority target amino acid residue Q209 in either GNAQ or GNA11. The GNAQ R183Q mutation is found in a small fraction of uveal melanomas. We report a patient with an unusual presentation of uveal melanoma arising at an early age in the setting of congenital skin and ocular surface melanosis. A 34-year-old Hispanic female with congenital bilateral nevus of Ota and ocular surface melanosis presented with progressive loss of visual acuity and was found to have a juxtapapillary uveal melanoma. She was treated with brachytherapy, but the tumor relapsed. She underwent enucleation that revealed mixed spindle and epithelioid uveal melanoma cells with no extraocular or lymphovascular spread. Next-generation sequencing performed on DNA isolated from the enucleation specimen identified a GNAQ R183Q mutation and a PMS1 truncation mutation. Cytogenetic profiling revealed no monosomy 3. These findings raise the possibility that uveal melanomas bearing G protein R183 mutations may have distinct clinicopathologic profiles compared to those with Q209 mutations. Furthermore, this is the first reported case of a mutation in the mismatch repair gene PMS1 associated with uveal melanoma.

Iris melanoma relapsing sixteen years after proton-beam therapy: The importance of lifelong follow-up

Purpose

To report a case of locally recurrent spindle-cell iris amelanotic melanoma 16 years after proton-beam therapy.

Observations

In 2001, a 45-year-old man presented with an amelanotic iris melanoma, extending from the 5 to 10 o'clock positions on his left eye. High-frequency ultrasonography showed extension of melanoma into the ciliary body. He was initially managed with proton-beam therapy (60 Gy delivered in four fractions over four consecutive days) and underwent ocular and systemic examination at regular intervals over the following years. Local tumor control was achieved, and the patient did not develop metastasis during sixteen consecutive years. In 2017, 16 years after he received proton-beam therapy, the patient developed a focal amelanotic lesion strongly suggestive of a local recurrence of iris melanoma, although it extended from the 1 to 6 o'clock positions. He also presented with treatment-resistant glaucoma with an intraocular pressure (IOP) of 37 mmHg, despite maximal topical IOP-lowering therapy. Since a second irradiation of the anterior segment was contraindicated, the eye was enucleated. Pathological analysis confirmed the diagnosis of iris melanoma and demonstrated iridocorneal angle invasion extending from the initial site to the recurrent tumor location.

Conclusions and importance

Regular ophthalmological surveillance for life with gonioscopy and high-frequency ultrasonography is recommended in patients with iris melanoma, due to the possibility of delayed local recurrence more than a decade after the initial treatment.

Computing uveal melanoma basal diameters: a comparative analysis of several novel techniques with improved accuracy

BACKGROUND

We sought to compare the accuracy of standard and novel echographic methods for computing intraocular tumor largest basal diameter (LBD).

DESIGN

Multicenter, retrospective cohort study.

SUBJECTS

All patients presenting with new diagnosis of uveal melanoma (UM).

METHODS

Ultrasounds were obtained for all patients, and axial length (AL) was measured for a subset of patients. LBD was calculated as: (1) a single chord measured on B scan ultrasound (one-chord method [1CM]), or (2) by subdividing the basal diameter into two chords, which were summated (two-chord method [2CM]), or (3) by a mathematically-derived formula (MF) based on geometric relationships. The accuracy of each method was then compared, and sensitivity of each technique to factors such as tumor size and AL were analyzed.

MAIN OUTCOME MEASURES

Accuracy, robustness, correctness of predicted plaque size.

RESULTS

116 UMs were analyzed; 1CM-calculated LBD underestimated 2CM-calculated LBD by 7.5% and underestimated LBD by MF by 7.8%; 2CM and MF were tightly correlated (average LBD difference = 0.038%). At larger LBDs, 1CM underestimated 2CM and MF by a much greater percentage (p < 0.001). By linear regression, 1CM underestimated LBD compared to 2CM by 0.8% and underestimated LBD compared to MF by 1.2% for every 1-mm LBD increase (p < 0.001 for each). Increasing the number of ultrasound chords beyond two did not significantly impact LBD calculations. For eyes with AL within two standard deviations of the mean, AL did not impact plaque selection using MF. 1CM would have led to selection of an undersized plaque in 41% of cases compared to 2CM and would have misclassified half of all eyes that actually required enucleation. For tumors with LBD < 12 mm, 1CM does not significantly underestimate LBD.

CONCLUSIONS

Tumor LBD by 1CM is an inaccurate means of determining actual LBD, especially for larger tumors. Using either 2CM or MF is much more accurate, especially for tumors > 12 mm, where a single chord on ultrasound is more likely to lead to incorrect, undersized plaque selection. Our MF can be applied with great accuracy even in cases where the AL of the eye is not measured, using the population average AL (23.7 mm), and the formula LBD = 23.7 sin - 1 ( chord length / 23.7 ) .

Regression rate of choroidal melanoma following iodine-125 brachytherapy is not associated with metastatic spread

Nearly half of choroidal melanomas progress to the metastatic stage at 15 years. The purpose of our study was to evaluate the prognostic value of tumour-height regression rate in medium-sized choroidal melanomas treated with iodine-125 brachytherapy. A retrospective cohort study was performed on 128 patients with medium-sized choroidal melanoma who were treated with iodine-125 brachytherapy. Tumour characteristics including tumour apical height at baseline and after irradiation, recurrence, metastasis and mortality were collected from patients' records. Regression rate was defined in mm/month or in percentage of baseline apical height. Patients were statistically stratified in three groups of regression rate at 6 months using the Ward's method and Euclidian distance (slow, medium and fast regression groups). Mean initial apical height was of 5.71±1.79 mm. At 6 months, the average regression rate was 0.02±0.12 mm/month in the slow group (n=60), 0.32±0.11 mm/month in the medium group (n=52) and 0.67±0.21 mm/month in the fast group (n=16). Cox regression analysis for the recurrence, metastasis and mortality rates according to the three groups did not show any statistically significant difference. Sensitivity analyses with the regression rates at 12 months showed similar associations. Exudative retinal detachment resolved with treatment at 5.9±4.0 months, and it was more common at presentation in the fast regression rate group. The regression rate at 6 and 12 months after iodine-125 brachytherapy is not associated with a higher metastatic rate in medium-sized choroidal melanoma.

Mortality after deferral of treatment or no treatment for choroidal melanoma

Purpose:

To report mortality of patients who were eligible for enrollment in the Collaborative Ocular Melanoma Study (COMS) clinical trials of medium-sized choroidal melanoma or large-sized choroidal melanoma but chose to defer treatment or receive no melanoma treatment.

Design:

Prospective nonrandomized multicenter cohort study as an adjunct to COMS randomized clinical trials.

Methods:

Patient follow-up procedures included examinations, correspondence, telephone contacts, and National Death Index searches. Primary outcome was patient death measured by all-cause mortality. Secondary outcomes were melanoma treatment and melanoma metastasis.

Results:

Of 77 patients eligible for COMS clinical trials who chose to defer or receive no melanoma treatment, 61 were appropriate candidates and 45 (74%) enrolled in the natural history study (NHS). In all, 42 patients (42 eyes) had medium melanoma, and the median follow-up was 5.3 years (range, 4–10.7 years). In all, 22 patients (52%) had subsequent melanoma treatment, and 20 (48%) had no melanoma treatment. For the 42 patients, Kaplan–Meier estimate of 5-year mortality was approximately 30% [95% confidence interval (CI), 18%–47%]. For COMS medium melanoma trial, 5-year mortality was 18% (95% CI, 16%–20%), not statistically significantly different from the NHS patients. After adjusting for differences in age and longest basal diameter, the 5-year risk of death for NHS patients versus COMS trial patients was 1.54 (95% CI, 0.93–2.56). Three patients had large melanoma. Melanoma metastasis was confirmed or suspected in 8 (42%) of 19 deaths.

Conclusion:

Greater mortality and higher risk of death for NHS patients are probative but not conclusive evidence of a beneficial, life-extending effect of medium melanoma treatment.

Initial evaluation of Advanced Collapsed cone Engine dose calculations in water medium for I-125 seeds and COMS eye plaques

PURPOSE

To investigate the dose calculation accuracy in water medium of the Advanced Collapsed cone Engine (ACE) for three sizes of COMS eye plaques loaded with low-energy I-125 seeds.

METHODS

A model of the Oncura 6711 I-125 seed was created for use with ACE in Oncentra^® Brachy (OcB) using primary-scatter separated (PSS) point dose kernel and Task Group (TG) 43 datasets. COMS eye plaque models of diameters 12, 16, and 20 mm were introduced into the OcB applicator library based on 3D CAD drawings of the plaques and Silastic inserts. To perform TG-186 level 1 commissioning, treatment plans were created in OcB for a single source in water and for each COMS plaque in water for two scenarios: with only one centrally loaded seed, or with all seed positions loaded. ACE dose calculations were performed in high accuracy mode with a 0.5 × 0.5 × 0.5 mm³ calculation grid. The resulting dose data were evaluated against Monte Carlo (MC) calculated doses obtained with MCNP6, using both local and global percent differences.

RESULTS

ACE doses around the source for the single seed in water agreed with MC doses on average within < 5% inside a 6 × 6 × 6 cm³ region, and within < 1.5% inside a 2 × 2 × 2 cm³ region. The PSS data were generated at a higher resolution within 2 cm from the source, resulting in this improved agreement closer to the source due to fewer approximations in the ACE dose calculation. Average differences in both investigated plaque loading patterns in front of the plaques and on the plaque central axes were ≤ 2.5%, though larger differences (up to 12%) were found near the plaque lip.

CONCLUSIONS

Overall, good agreement was found between ACE and MC dose calculations for a single I-125 seed and in front of the COMS plaques in water. More complex scenarios need to be investigated to determine how well ACE handles heterogeneous patient materials.

Efficacy and Safety of Low-Dose Iodine Plaque Brachytherapy for Juxtapapillary Choroidal Melanoma

PURPOSE

To evaluate low- vs high-dose plaque brachytherapy for juxtapapillary choroidal melanoma.

DESIGN

Retrospective interventional case series.

METHODS

Setting: Single institution.

STUDY POPULATION

Forty-seven patients with juxtapapillary choroidal melanoma.

INTERVENTION

Iodine-125 plaque brachytherapy. Eyes were divided into apex low-dose (LD) and high-dose (HD) groups (≤ or > median apex dose 84.35 Gy). Main outcome measures were time to distant failure, local failure, death, enucleation, radiation retinopathy, optic neuropathy, and best-corrected visual acuity (BCVA).

RESULTS

Freedom from distant failure rates were 96% and 95% in apex LD and HD groups at 5 years and 77% and 95% at 10 years, respectively (P = .84). Freedom from local failure rates were 90% in the apex LD group vs 89% in the HD group at 5 and 10 years (P = .96). Apex LD and HD groups did not differ for time to death or enucleation. Five- and 10-year freedom from radiation retinopathy and optic neuropathy rates were higher in the apex LD than HD group. Loss of ≥3 BCVA lines, final BCVA 20/40 or better, and final BCVA 20/200 or worse were more favorable in the 5 mm LD compared to HD group. Visual acuity outcomes did not differ between apex LD and HD groups.

CONCLUSIONS

Low-dose iodine-125 plaque brachytherapy (67.5-81 Gy at tumor apex) provides safe and effective tumor control for juxtapapillary choroidal melanoma and may be associated with reduced radiation toxicity. Larger trials are needed to determine the optimal therapeutic dose for juxtapapillary choroidal melanoma.

Guidelines by the AAPM and GEC-ESTRO on the use of innovative brachytherapy devices and applications: Report of Task Group 167

Although a multicenter, Phase III, prospective, randomized trial is the gold standard for evidence-based medicine, it is rarely used in the evaluation of innovative devices because of many practical and ethical reasons. It is usually sufficient to compare the dose distributions and dose rates for determining the equivalence of the innovative treatment modality to an existing one. Thus, quantitative evaluation of the dosimetric characteristics of innovative radiotherapy devices or applications is a critical part in which physicists should be actively involved. The physicist's role, along with physician colleagues, in this process is highlighted for innovative brachytherapy devices and applications and includes evaluation of (1) dosimetric considerations for clinical implementation (including calibrations, dose calculations, and radiobiological aspects) to comply with existing societal dosimetric prerequisites for sources in routine clinical use, (2) risks and benefits from a regulatory and safety perspective, and (3) resource assessment and preparedness. Further, it is suggested that any developed calibration methods be traceable to a primary standards dosimetry laboratory (PSDL) such as the National Institute of Standards and Technology in the U.S. or to other PSDLs located elsewhere such as in Europe. Clinical users should follow standards as approved by their country's regulatory agencies that approved such a brachytherapy device. Integration of this system into the medical source calibration infrastructure of secondary standard dosimetry laboratories such as the Accredited Dosimetry Calibration Laboratories in the U.S. is encouraged before a source is introduced into widespread routine clinical use. The American Association of Physicists in Medicine and the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) have developed guidelines for the safe and consistent application of brachytherapy using innovative devices and applications. The current report covers regulatory approvals, calibration, dose calculations, radiobiological issues, and overall safety concerns that should be addressed during the commissioning stage preceding clinical use. These guidelines are based on review of requirements of the U.S. Nuclear Regulatory Commission, U.S. Department of Transportation, International Electrotechnical Commission Medical Electrical Equipment Standard 60601, U.S. Food and Drug Administration, European Commission for CE Marking (Conformité Européenne), and institutional review boards and radiation safety committees.

Iodine-125 Brachytherapy for Uveal Melanoma: A Systematic Review of Radiation Dose

AIM

To investigate whether lower radiation doses may yield similar outcome measures to those from the COMS trial.

METHODS

A literature review of English language articles was performed using the PubMed database of the U.S. National Library of Medicine and the Cochrane Central Register of Controlled Trials using the following keywords: uveal melanoma, choroidal melanoma, primary uveal malignant melanoma, iodine-125 brachytherapy, local recurrence, local treatment failure, and local tumor control. The relationships between study local recurrence rate and median dosage were tested by linear regression, with each study weighted by the number of patients included.

RESULTS

Fifteen retrospective and prospective studies were selected for systematic review (2,662 patients). Ranges of reported mean or median radiation dose to tumor apex were 62.5-104.0 Gy. Local recurrence rates ranged from 0 to 24%. A 1.0-Gy increase in the average study dose was associated with a 0.14% decrease in local recurrence rate, which was not statistically significant (p value 0.336).

CONCLUSION

The gold standard empirically derived 85.0-Gy radiation dose for the treatment of uveal melanoma could be tested in a randomized study.

Time trends in personnel certification and turnover in the Collaborative Ocular Melanoma Study

Background The purpose of this analysis was to examine and quantify the coordinating center workload in regard to certification and turnover of clinical personnel who participated in the Collaborative Ocular Melanoma Study (COMS).

Methods The COMS was a set of multicenter, multidisciplinary randomized clinical trials conducted to evaluate radiotherapy for initial treatment of choroidal melanoma, a primary eye cancer. Patients were screened, enrolled, treated, and followed for mortality and clinical outcomes at 43 clinical centers in the United States and Canada, beginning late in 1986. Clinical centers were added to the COMS during three calendar periods. Training and certification of clinical personnel was performed by five resource centers and coordinated at the COMS coordinating center. A personnel database was maintained at the coordinating center for tracking certification progress, recertification, transfers and resignations. Certification records were analyzed for the period 1986 through 1998 when patient accrual and treatment were completed.

Results Clinical personnel (929 individuals) were certified for one or more of nine distinct roles in the COMS, resulting in 1342 certifications; 26% were certified for two or more positions. The total number certified for each role ranged from 114 to 208. Certifications per year ranged from 260 in 1987 to 35 in 1997. The certification workload at the coordinating center rose following addition of each group of new clinical centers. It also increased in 1995 as a result of recertification of current personnel mandated by the external data monitoring committee.

Conclusions This analysis documented that training and certification were continuing tasks, and not limited to initiation of the study. Resignations and reassignments of certified personnel were responsible for 642 decertifications.

[Size-based classification of choroidal melanoma and its role in treatment decision-making]

AIM

To specify indications for brachytherapy (BT) in large choroidal melanoma (CM) so that tumor size and vital prognosis were considered.

MATERIAL AND METHODS

We retrospectively analyzed data from 161 CM patients who were treated with BT and followed-up at either the Ophthalmological Clinical Hospital or some other Moscow medical facility and also registered by the City Cancer Registry.

RESULTS

Patient age at the time of starting the treatment lied within the range of 17 to 84 years and averaged 56.89±1.93 years. During the follow-up period (12-275 months, 95.65±8.4 months on average) hematogenous metastases were found in 23 (14.29%) patients. Liver involvement was diagnosed in 8 patients within the average of 23.13 months after treatment. Their average survival time was 11 months. A total of 142 patients were followed up for more than 36 months (104.87 months on average). Of them, 15 patients were diagnosed with metastatic CM within 37-167 months after BT (80.27 months on average). Despite metastatic disease they generally survived 2.8 time longer than the aforementioned patients (30.8 months). The cases were then divided into 3 groups according to J. Shields classification of CM. Small melanoma patients did not develop metastases within 99.96±12.47 months of follow-up. In medium melanomas, as many as 13.35% of cases were metastatic (with the average survival time of 20.66 months); in large melanomas - 19.51% (with the average survival time of 13.5 months).

CONCLUSION

Treatment modality and follow-up periods being the same (7-8 years after BT), larger choroidal melanomas has been shown to be associated with higher risk of hematogenous metastases. For local treatment to be successive, the maximal diameter of the tumor should not exceed 10 mm. Every fifth patient of those with CM larger than 15 mm is likely to develop hematogenous metastases. The results obtained indicate the necessity of decreasing the size thresholds for choroidal melanomas, small and medium in the first place.

Macroscopic techniques for ophthalmic tumor specimens

This article explores the range of tumor specimens that may be submitted to ophthalmic pathology. The handling of complex enucleation and exenteration is described along with smaller eyelid, conjunctival and corneal specimens. The importance of a good understanding of the unique anatomy of the ocular region and detailed clinical information is emphasized as this results in the taking of appropriate blocks for histology and consequently clinically helpful reports. Recommendations for handling specimens where further tissue is required for molecular studies is discussed.

Episcleral eye plaque dosimetry comparison for the Eye Physics EP917 using Plaque Simulator and Monte Carlo simulation

This work is a comparative study of the dosimetry calculated by Plaque Simulator, a treatment planning system for eye plaque brachytherapy, to the dosimetry calculated using Monte Carlo simulation for an Eye Physics model EP917 eye plaque. Monte Carlo (MC) simulation using MCNPX 2.7 was used to calculate the central axis dose in water for an EP917 eye plaque fully loaded with 17 IsoAid Advantage  125I seeds. In addition, the dosimetry parameters Λ, gL(r), and F(r,θ) were calculated for the IsoAid Advantage model IAI‐125  125I seed and benchmarked against published data. Bebig Plaque Simulator (PS) v5.74 was used to calculate the central axis dose based on the AAPM Updated Task Group 43 (TG‐43U1) dose formalism. The calculated central axis dose from MC and PS was then compared. When the MC dosimetry parameters for the IsoAid Advantage  125I seed were compared with the consensus values, Λ agreed with the consensus value to within 2.3%. However, much larger differences were found between MC calculated gL(r) and F(r,θ) and the consensus values. The differences between MC‐calculated dosimetry parameters are much smaller when compared with recently published data. The differences between the calculated central axis absolute dose from MC and PS ranged from 5% to 10% for distances between 1 and 12 mm from the outer scleral surface. When the dosimetry parameters for the  125I seed from this study were used in PS, the calculated absolute central axis dose differences were reduced by 2.3% from depths of 4 to 12 mm from the outer scleral surface. We conclude that PS adequately models the central dose profile of this plaque using its defaults for the IsoAid model IAI‐125 at distances of 1 to 7 mm from the outer scleral surface. However, improved dose accuracy can be obtained by using updated dosimetry parameters for the IsoAid model IAI‐125  125I seed.

PACS number: 87.55.K‐

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.

Examining and processing eye specimens

This chapter provides basic and useful information about handling and processing eye specimens as well as diagnosing common diseases encountered by ophthalmic pathologists. Each section is devoted to a specific part of the eye (cornea, conjunctiva, iris and cilliary body, choroid, retina, vitreous, and the optic nerve), providing useful pearls about the basic anatomy, disease processes, special staining, and tissue processing.