Combined brachytherapy and transpupillary thermotherapy for large choroidal melanoma: tumor regression and early complications

Local tumor control and treatment related toxicity after plaque brachytherapy for uveal melanoma: A systematic review and a data pooled analysis

Uveal melanoma (UM) represents the most common primary intraocular tumor, and nowadays eye plaque brachytherapy (EPB) is the most frequently used visual acuity preservation treatment option for small to medium sized UMs. The excellent local tumor control (LTC) rate achieved by EPB may be associated with severe complications and adverse events. Several dosimetric and clinical risk factors for the development of EPB-related ocular morbidity can be identified. However, morbidity predictive models specifically developed for EPB are still scarce. PRISMA methodology was used for the present systematic review of articles indexed in PubMed in the last sixteen years on EPB treatment of UM which aims at determining the major factors affecting local tumor control and ocular morbidities. To our knowledge, for the first time in EPB field, local tumor control probability (TCP) and normal tissue complication probability (NTCP) modelling on pooled clinical outcomes were performed. The analyzed literature (103 studies including 21,263 UM patients) pointed out that Ru-106 EPB provided high local control outcomes while minimizing radiation induced complications. The use of treatment planning systems (TPS) was the most influencing factor for EPB outcomes such as metastasis occurrence, enucleation, and disease specific survival, irrespective of radioactive implant type. TCP and NTCP parameters were successfully extracted for 5-year LTC, cataract and optic neuropathy. In future studies, more consistent recordings of ocular morbidities along with accurate estimation of doses through routine use of TPS are needed to expand and improve the robustness of toxicity risk prediction in EPB.

Blue-Light Fundus Autofluorescence Imaging following Ruthenium-106 Brachytherapy for Choroidal Melanoma

PURPOSE

To describe changes in blue-light fundus autofluorescence (FAF) and corresponding alterations in optical coherence tomography (OCT) within the irradiation field after ruthenium-106 brachytherapy (RBT) for choroidal melanoma.

METHODS

Consecutive patients with choroidal melanoma were included in a retrospective case series. Patients were treated with RBT at a single institution. As part of their routine examination patients underwent multimodal imaging including ultrasonography, fundus photography, OCT, and FAF imaging (excitation = 488 nm). FAF images were analysed for changes within the irradiation field.

RESULTS

31 patients (mean age 65.7 years) were treated with RBT for unilateral choroidal melanoma. Mean tumour height before therapy was 2.7 mm (SD 1.0). Mean follow-up time was 23.3 months (SD 13.3). Main FAF characteristics attributable to RBT emerged as increased FAF with speckled decreased FAF (FAF mottling) within the irradiation field and a rim of increased FAF at its border. OCT scans demonstrated loss of the ellipsoid zone and the external limiting membrane, thinning of the neurosensory retina, and alterations of the retinal pigment epithelium like clumping, migration, and atrophy.

CONCLUSIONS

FAF changes in the irradiation field after RBT of choroidal melanomas follow a characteristic pattern that correlates with distinct OCT alterations. FAF and OCT imaging give additional information to monitor effects of RBT and, therefore, complement multimodal imaging techniques after plaque therapy.

[Local treatment of choroidal melanoma: possibilities and limitations]

Local treatment of choroidal melanoma (CM) attracts the attention of many ophthalmology specialists, especially in recent years as the capabilities to target irradiation at small objects and possibilities of surgical interventions on the eyeball have expanded. The article discusses the medical indications for local treatment of CM. Review of literature of the last 16 years and author's own observations on CM patients who underwent almost all kinds of conventional methods of local treatment allowed thorough analysis of indications and counter-indications for their usage. Among the authors who favor local destruction and removal of large CM, the main indication is the possibility to preserve vision and anatomical structures of the eye. This led to unreasonably wide spread of local destruction (removal) of large CM, primarily the endovitreal resection method. However, such metastasis risk factors as CM size and its localization are being overlooked. Literature analysis and author's own observations helped validate the unsafety of the local treatment of large CM. The article features long-term results of contact and distant radiation therapy, and presents CM metrics for best therapeutic effect.

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 ) .

Stereotactic radiotherapy for choroidal melanomas by means of HybridArc™ : Physics and technique of linac-based photon beam therapy

PURPOSE

Stereotactic radiotherapy (SRT) is suitable to treat ocular tumours. The optimal beam geometry for SRT, however, has not been defined. Here we evaluate a combination technique with dynamic conformal arcs (DCAs) and intensity-modulated static fields (IMRT), known as HybridArc™ (HA).

METHODS

For the first consecutive 25 cases with choroidal melanomas with volumes of 0.02 to 1.18 cm³ treated with 50 Gy in five fractions, the results with respect to dose conformity, homogeneity, and dose distributions were summarised. To describe the dose distribution at the planning target volume (PTV) boundary, we defined a spatially averaged dose gradient (SADG) and compared it with Paddick's gradient index (GI). We made dosimetric comparisons between HA and other irradiation techniques.

RESULTS

The PTVs ranged from 0.42 to 3.37 cm³. The conformity index (CI) was 1.25 ± 0.15, and the homogeneity index (HI) 0.08 ± 0.02. The SADG was (-3.5 ± 0.5) Gy/mm or (-7.0 ± 1.0) %/mm between the isodose levels 95 and 20%; local minima reached -11.5 Gy/mm or -22.9%/mm. The coefficient of determination for a nonlinear regression of GI on SADG was 0.072. After a median follow-up time of 19.6 months, local tumour control was 100% without any case of post-therapeutic enucleation. Two patients (8%) developed liver metastases.

CONCLUSION

SRT of ocular tumours by HA is highly appropriate, and HA is superior to intensity-modulated arc therapy (IMAT) concerning dose reduction in organs at risk (OARs). The novel gradient measure SADG is more informative than Paddick's GI.

Plaque brachytherapy for posterior uveal melanoma in 2018: improved techniques and expanded indications

PURPOSE OF REVIEW

Plaque brachytherapy remains the dominant globe-sparing therapy of uveal melanoma. This report highlights recent advances, which have expanded plaque brachytherapy's uses as well as improved the surgical technique.

RECENT FINDINGS

Plaque brachytherapy is effective for tumors that may previously have demanded enucleation. Plaque brachytherapy can be used to control large melanomas as well as melanomas touching the optic nerve. Improvements in planning and design have made plaque therapy simpler for the surgical operator and may reduce collateral radiation damage to normal ocular structures. The COMS implies a required dose of 85 Gy to the tumor apex for treatment of uveal melanoma. However, multiple reports indicate that lower doses may be equally effective for tumor control while reducing radiation dose to uninvolved structures. Vitreoretinal surgeons can be called upon safely to treat long-term side effects of radiation or tumor death such as intractable vitreous hemorrhage or inflammation. Further, vitreoretinal surgeons have employed tumor endoresection as primary local tumor control or in combination with plaque brachytherapy.

SUMMARY

Plaque brachytherapy for uveal melanoma remains highly effective for local tumor control and prevention of metastasis. Indications for plaque brachytherapy have expanded, and the technique has improved.

Ruthenium-106 Brachytherapy with or without Additional Local Therapy Shows Favorable Outcome for Variable-Sized Choroidal Melanomas in Korean Patients

Purpose

The purpose of this study was to report clinical outcomes of ruthenium-106 (¹⁰⁶Ru) brachytherapy with or without additional local therapy for choroidal melanomas in Korean patients.

Materials and Methods

A total of 88 patients diagnosed with choroidal melanomas were treated with ¹⁰⁶Ru brachytherapy between 2006 and 2012. Patients were divided into two groups according to their tumor height: a large group (≥ 6 mm, n=50) and a small group (< 6 mm, n=38). Most patients in the large group received combined therapy with local excision and/or transpupillary thermotherapy. In general, 85-95 Gy was administered to the apex of the tumor, while 100 Gy was administered to the point 2-6 mm from the outer surface of the sclera for patients undergoing combined therapy.

Results

The median follow-up duration was 30 months. The 3-year local control rate was significantly higher in the small group than in the large group (94% vs. 70%, p=0.047). The free from distant metastasis (FFDM) rate and the overall survival (OS) rate were also higher in patients in the small group (3-year FFDM, 97% vs. 76%; p=0.031 and 3-year OS, 97% vs. 72%; p=0.036). A total of 13 patients underwent enucleation. The eye-preservation rate was also higher in the small group (3-year eye-preservation rate, 94% vs. 70%; p=0.050), and tumor height was a significant prognostic factor for eye-preservation.

Conclusion

¹⁰⁶Ru brachytherapy showed favorable outcomes in small choroidal melanomas in Korean patients. Although additional local treatment could improve eye-preservation rate for large tumors, other strategies should be considered for disease control.

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.

Ruthenium-106 brachytherapy for thick uveal melanoma: reappraisal of apex and base dose radiation and dose rate

Purpose

To evaluate the outcomes of ruthenium-106 (¹⁰⁶Ru) brachytherapy in terms of radiation parameters in patients with thick uveal melanomas.

Material and methods

Medical records of 51 patients with thick (thickness ≥ 7 mm and < 11 mm) uveal melanoma treated with ¹⁰⁶Ru brachytherapy during a ten-year period were reviewed. Radiation parameters, tumor regression, best corrected visual acuity (BCVA), and treatment-related complications were assessed.

Results

Fifty one eyes of 51 consecutive patients including 25 men and 26 women with a mean age of 50.5 ± 15.2 years were enrolled. Patients were followed for 36.1 ± 26.5 months (mean ± SD). Mean radiation dose to tumor apex and to sclera were 71 (± 19.2) Gy and 1269 (± 168.2) Gy. Radiation dose rates to tumor apex and to sclera were 0.37 (± 0.14) Gy/h and 6.44 (± 1.50) Gy/h. Globe preservation was achieved in 82.4%. Preoperative mean tumor thickness of 8.1 (± 0.9) mm decreased to 4.5 (± 1.6) mm, 3.4 (± 1.4) mm, and 3.0 (± 1.46) mm at 12, 24, and 48 months after brachytherapy (p = 0.03). Four eyes that did not show regression after 6 months of brachytherapy were enucleated. Secondary enucleation was performed in 5 eyes because of tumor recurrence or neovascular glaucoma. Tumor recurrence was evident in 6 (11.8%) patients. Mean Log MAR (magnification requirement) visual acuity declined from 0.75 (± 0.63) to 0.94 (± 0.5) (p = 0.04). Best corrected visual acuity of 20/200 or worse was recorded in 37% of the patients at the time of diagnosis and 61.7% of the patients at last exam (p = 0.04). Non-proliferative and proliferative radiation-induced retinopathy was observed in 20 and 7 eyes.

Conclusions

Thick uveal melanomas are amenable to ¹⁰⁶Ru brachytherapy with less than recommended apex radiation dose and dose rates.

Current and emerging treatment options for uveal melanoma

Uveal melanoma (UM) is the most common primary malignant intraocular tumor in adults, with a 10-year cumulative metastatic rate of 34%. The most common site of metastasis is the liver (95%). Unfortunately, the current treatment of metastatic UM is limited by the lack of effective systemic therapy. Options for the management of the primary intraocular tumor include radical surgery as well as conservative treatments in order to preserve visual acuity. For metastatic disease, several approaches have been described with no standard method. Nevertheless, median survival after liver metastasis is poor, being around 4–6 months, with a 1-year survival of 10%–15%. In this review, the authors summarize current and promising new treatments for UM.

Indigenous (125)I brachytherapy source for the management of intraocular melanomas in India

Episcleral plaque brachytherapy using (125)I seed is a viable option for the management of intraocular cancer with minimal invasiveness and surgical complications. This article describes the fabrication of (125)I seeds and initial experience on their use for the management of intraocular choroidal melanomas. The process of (125)I seed fabrication includes immobilization of (125)I into palladium-coated silver wires, its encapsulation in titanium capsules using Nd: YAG laser and quality control to assure safety. Plaque preparation consists of the assignment of seeds to slots on the plaque to achieve a desired dose rate distribution. The clinical study reported here includes the retrospective review of 9 eyes of 9 patients who underwent ophthalmic brachytherapy between May 2008 and June 2011. The average apical diameter before brachytherapy was 7.6 mm and the average largest basal diameter was 12.1 mm, which reduced to 3.3 and 7.2 mm, respectively, after the procedure at an average follow-up of 24 months. Patients in our studies experienced good local tumor control. The results of this study represent a significant step forward in the management of intraocular tumors in India.

Intravitreal bevacizumab combined with plaque brachytherapy reduces melanoma tumor volume and enhances resolution of exudative detachment

Background

The purpose of this study was to evaluate intravitreal bevacizumab as an adjuvant treatment to plaque brachytherapy in the treatment of choroidal melanoma.

Methods

This was a retrospective, consecutive study of 124 patients treated from 2007 to 2009 for choroidal melanoma with plaque brachytherapy. Patients were treated with I-125 plaque brachytherapy with 2 mm margins and 85 Gy to the tumor apex. Consecutive patients were injected intravitreally with 2.5 mg/0.1 mL bevacizumab at a site away from the primary tumor and immediately following plaque removal. Choroidal melanomas were observed using indirect ophthalmoscopy, wide-angle photography, and ultrasound. The main outcome measures were tumor volume, resolution of exudative retinal detachment, and visual acuity.

Results

One hundred and twenty-four patients met our inclusion criteria and were included in the analysis. The mean patient age was 65.7 years, and the mean apical tumor height was 4.0 ± 2.7 mm and basal diameter was 12.7 ± 3.0 mm. Mean follow-up was 24 months. Prior to treatment, 100% of tumors had exudative retinal detachment, and pretreatment visual acuity was 20/55 (median 20/40). Tumor control was 100%, metastasis was 0% at last follow-up, and 89.8% had complete resolution of exudative retinal detachment, with a mean time to resolution of 3.36 months. At one month, 43% had complete resolution of exudative retinal detachment, which increased to 73% at 4 months. Visual acuity was 20/62 (median 20/40) at 4 months, with stabilization to 20/57 (median 20/40) at 8 months, 20/56 (median 20/30) at 12 months, and 20/68 (median 20/50) at 24 months. Tumor volume following combined therapy was shown to be reduced by 22.2% at 3 months, 28.9% at 6 months, 39.3% at 12 months, and 52.2% at 24 months (all P < 0.001). All patients tolerated the procedure well without systemic side effects.

Conclusion

Intravitreal bevacizumab may be used as an adjuvant agent following plaque brachytherapy. Treated choroidal melanomas show reduction in tumor volume as well as resolution of exudative retinal detachments.

The comparison of ruthenium brachytherapy and simultaneous transpupillary thermotherapy of choroidal melanoma with brachytherapy alone

PURPOSE

To compare the outcomes of combined treatment of choroidal melanoma with ruthenium brachytherapy (BT) simultaneously with transpupillary thermotherapy (TTT) and treatment with BT alone.

METHODS AND MATERIALS

Two matched groups of patients, one treated with BT and simultaneous TTT (Group BT+TTT, n=63), the other treated with BT alone (Group BT, n=70) were analyzed retrospectively. The main outcome measures were rate of tumor regression, recurrences, enucleations, metastases, recurrence-free and overall survival rate, and visual acuity, assessed by Kaplan-Meier analysis.

RESULTS

Patients were matched according to mean age (p=0.22), mean tumor thickness (6.4 vs. 6.25mm, range 2.5-10.8mm, p=0.59), and mean length of followup (42 vs. 34.4 months, range 3-109, p=0.052). Tumor largest basal diameter (13.0 vs. 12.9mm), tumor location, and mean radiation dose (apical 135 vs. 136Gy and scleral 1294 vs. 1438Gy) were also similar in both groups (p>0.1). Treatment with BT+TTT resulted in higher rate of tumor regression (63% vs. 49%, respectively, p=0.036), lower 5-year tumor recurrence rate (96% vs. 83%, p<0.034), and higher eye-globe preservation (98% vs. 87%, p<0.024) and recurrence-free survival rates (89% vs. 67%, p<0.017) than treatment with BT alone. There was no difference in complications (p>0.5), metastasis-free (93% vs. 81%, p>0.22) and overall survival rates (91% vs. 81%, p>0.39), or in visual outcomes.

CONCLUSION

Combined treatment of choroidal melanoma with ruthenium BT and simultaneous TTT seems to provide higher local control, eye-globe preservation, and recurrence-free survival rates than treatment with BT alone and results in similar rates of metastases and overall survival.

Incidence of cataract and outcomes after cataract surgery in the first 5 years after iodine 125 brachytherapy in the Collaborative Ocular Melanoma Study: COMS Report No. 27

PURPOSE

To evaluate the effect of the radiation dose to the lens on cataract formation and effect of cataract surgery on visual acuity (VA) among patients with choroidal melanoma treated with iodine 125 (I125) brachytherapy.

DESIGN

Prospective study of patients enrolled in one arm of a randomized clinical trial.

PARTICIPANTS

Patients enrolled in the Collaborative Ocular Melanoma Study (COMS) who received I125 brachytherapy as randomly assigned and also were phakic, with no history of cataract in the study eye at the time of enrollment (n = 532).

METHODS

Each follow-up examination included an interim ocular history and full ophthalmic examination. Lens status (phakic, pseudophakic, or aphakic) and best-corrected VA were recorded. For the purpose of this analysis, the date of the first examination at which an eye was reported to be aphakic or pseudophakic, to have vision-limiting lenticular opacities, or to have had cataract surgery was defined as the observed time of cataract development. Date of cataract surgery was defined as the date of the first follow-up examination at which cataract surgery was reported.

MAIN OUTCOME MEASURES

Incidence of cataract and outcomes after cataract surgery.

RESULTS

During the first 5 years of follow-up, cataracts developed in 362 (68%) of the 532 study eyes, including 49 (9%) that had had cataract surgery. By 5 years, 83% of study eyes were reported to have a cataract (95% confidence interval [CI], 79%-87%), and 12% had undergone cataract surgery (CI, 9%-15%) in the study eye. Eighteen percent of eyes that received a dose of 24 Gy or higher to the lens underwent cataract surgery, whereas only 4% of patients with <12 Gy to the lens underwent cataract surgery. Median VAs were 20/125 before cataract surgery and 20/50 after cataract surgery. After cataract surgery, VA improved by 2 lines or more in 32 (66%) patients and remained stable in 13 (26%) patients. The most common cause of lack of visual improvement after cataract surgery was presence of radiation retinopathy.

CONCLUSION

Although cataract surgery was infrequent among COMS patients, VA remained stable or improved in the majority of these eyes after cataract surgery.