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.

Dosimetric Investigation of Six Ru-106 Eye Plaques by EBT3 Radiochromic Films and Monte Carlo Simulation.

Background: Ophthalmic brachytherapy using radioactive plaques is an effective technique for the treatment of uveal melanoma. Ru-106 eye plaques are considered as interesting issue due to their steep gradient dose. The pre-planning evaluation of dosimetric parameters is essential for the treatment planning system. Objective: The current study aims at providing dose distributions of six Ru-106 eye plaques (CCA, CCB, CGD, CIB, COB and COD) using radiochromic EBT3 film, Geant4 Monte Carlo toolkit and the treatment planning software (Plaque Simulator). Material and Methods: In this experimental study, an in-house phantom was employed for depth dose measurements with EBT3 films. Also, Geant4.10.5 scoring mesh was implemented to obtain the 2D dose distribution of the plaques. The results were compared with Plaque Simulator software and the manufacturer's (BEBIG) data. The gamma index criterion (3%/3 mm) was used to evaluate dose distributions obtained by the film measurements and Geant4 simulation. Results: A good agreement was achieved between simulation and experimental results. Gamma index passing rate was 94.2%, 89.3%, 88.2%, 82.2%, 92.2% and 90.1% for CCA, CCB, CGD, CIB, COB and COD plaques, respectively. Absolute dose rate (mGy/min) obtained by EBT3 film at the depth of 2 mm was 79.4 mGy/min, 81.0 mGy/min, 78.6 mGy/min, 62.2 mGy/min, 75.2 mGy/min and 81.2 mGy/min for CCA, CCB, CGD, CIB, COB and COD plaques, respectively. Conclusion: The measured dose distributions and lateral dose profiles may be utilized in the treatment planning system to cover clinical volumes such as the clinical target volume and the gross tumor volume.

Evaluation of radiation maculopathy after treatment of choroidal melanoma with ruthenium-106 using optical coherence tomography angiography.

BACKGROUND: To assess the impact of brachytherapy on macular microvasculature utilizing optical coherence tomography angiography (OCTA) in treated choroidal melanoma. METHODS: In this retrospective observational case series, we reviewed the recorded data of the patients with unilateral extramacular choroidal melanoma treated with ruthenium - 106 (106Ru) plaque radiotherapy with a follow-up period of more than 6 months. Automatically measured OCTA retinal parameters were analysed after image processing. RESULTS: Thirty-one eyes of 31 patients with the mean age of 51.1 years were recruited. Six eyes had no radiation maculopathy (RM). From 25 eyes with RM, nine eyes (36%) revealed a burnout macular microvasculature with imperceptible vascular details. Twenty-one non-irradiated fellow eyes from the enrolled patients were considered as the control group. Foveal and optic disc radiation dose had the highest value to predict the burnout pattern (ROC, AUC: 0.763, 0.727). Superficial and deep foveal avascular zone (FAZ) were larger in irradiated eyes in comparison to non-irradiated fellow eyes (1629 µm2 vs. 428 µm2, P = 0.005; 1837 µm2 vs 268 µm2, P = 0.021; respectively). Foveal and parafoveal vascular area density (VAD) and vascular skeleton density (VSD) in both superficial and deep capillary plexus (SCP and DCP) were decreased in all irradiated eyes in comparison with non-irradiated fellow eyes (P < 0.001). Compared with non-irradiated fellow eyes, irradiated eyes without RM had significantly lower VAD and VSD at foveal and parafoveal DCP (all P < 0.02). However, these differences at SCP were not statistically significant. CONCLUSION: The OCTA is a valuable tool for evaluating RM. Initial subclinical microvascular insult after 106Ru brachytherapy is more likely to occur in DCP. The deep FAZ area was identified as a more critical biomarker of BCVA than superficial FAZ in these patients.

Comparison of Iodide-125 and Ruthenium-106 Brachytherapy in the Treatment of Choroidal Melanomas.

BACKGROUND: To compare iodine-125 (125I) with ruthenium-106 (106Ru) episcleral plaque radiation therapy in terms of the effectiveness and non-inferiority for choroidal melanoma treatment. OBJECTIVE: To report the non-inferiority of new made iodine-125 (125I) compared with ruthenium-106 (106Ru) episcleral plaque radiation. PATIENTS AND METHODS: A retrospective, non-randomized comparative case series. In this series the patients treated with 125I and 106Ru episcleral plaques for choroidal melanoma between September 2013 and August 2017 at Farabi Hospital are compared. Local control of choroidal melanomas after 125I and 106Ru plaques implantation and vision changes are the main outcome measures. RESULTS: A total of 35 patients were identified (125I = 15, 106Ru = 20). No significant difference between two groups in visual acuity, diameter and thickness changes were observed after treatment. Multivariate linear regression (MLR) analysis showed that final diameter was only, independently and significantly, correlated with the pre-treatment diameter of the tumor (ß = 0.59, 95% confidence interval [CI]: 0.29, 1.34, P = 0.003). The same MLR analysis for the final thickness and visual acuity, after adjusting for age and sex showed no significant difference between two groups. A single patient treated with 106Ru had local tumor recurrence with no one in the 125I group. No statistical difference in the rate of ocular complications was observed. CONCLUSION: The treatment with our 125I plaques is as effective as 106Ru plaques in controlling choroidal melanoma tumor and preserving the vision during the two and half year of follow-up. The complication rates are alike. It means that the effectiveness of 125I is not only comparable to 106Ru but also superior when the outcome of the interest is the thickness of the tumors.

Effect of induced inner curvature on refractive index sensitivity in internally tilted long-period gratings.

A new complete analysis of the effect of induced inner curvature on refractive index (RI) sensitivity in internally tilted long-period gratings (ITLPGs) is presented. The responses in terms of RI sensitivity of a standard LPG and different ITLPGs with curvature values between 15 and 19 m-1 were compared. The analysis suggests first, that the larger the induced curvature, the greater the RI sensitivity; and second, that the RI sensitivity exponentially increases with both the curvature and cladding mode order. RI sensitivity greater than 100 nm RIU-1 can be attained with curvature greater than 25 m-1 for LP06 mode. Conversely, the temperature sensitivity of ITLPGs is comparable to standard LPGs for the considered cladding mode order.

SPR-based plastic optical fibre biosensor for the detection of C-reactive protein in serum.

A plastic optical fibre biosensor based on surface plasmon resonance for the detection of C-reactive protein (CRP) in serum is proposed. The biosensor was integrated into a home-made thermo-stabilized microfluidic system that allows avoiding any thermal and/or mechanical fluctuation and maintaining the best stable conditions during the measurements. A working range of 0.006-70 mg L-1 and a limit of detection of 0.009 mg L-1 were achieved. These results are among the best compared to other SPR-based biosensors for CRP detection, especially considering that they were achieved in a real and complex medium, i.e. serum. In addition, since the sensor performances satisfy those requested in physiologically-relevant clinical applications, the whole biosensing platform could well address high sensitive, easy to realize, real-time, label-free, portable and low cost diagnosis of CRP for future lab-on-a-chip applications. 3D sketch (left) of the thermo-stabilized home-made flow cell developed to house the SPR-based plastic optical fibre biosensor. Exemplary response curve (shift of the SPR wavelength versus time) of the proposed biosensor (right) for the detection of C-reactive protein in serum.