Combined plaque radiotherapy and transpupillary thermotherapy in choroidal melanoma: 5 years' experience

Laser treatment for choroidal melanoma: Current concepts

Laser treatment has offered a relatively nonsurgical alternative for eye, life, and vision-sparing treatment of malignant melanoma of the choroid. Historically, the most commonly used forms of lasers were xenon-arc, argon laser, krypton laser, and the more recent transpupillary thermotherapy (TTT) and photodynamic therapy (PDT). Melanomas selected for laser treatment tend to be smaller and visibly accessible, which means these tumors are usually located in the posterior choroid. Laser treatments have been associated with both local tumor destruction and side effects. Unlike radiation therapy, laser treatment has been commonly associated with retinal traction, hemorrhage, chorioretinal neovascularization, and extra scleral tumor extension, as well as higher rates of local treatment failure. In addition, however, laser-treatment has been successfully used to treat tumor-related retinal detachments, radiation retinopathy, and neovascular glaucoma. We review the world's experience of ophthalmic laser treatment for choroidal melanoma, offer safety and efficacy guidelines, as well as a comparison of laser treatment to radiation therapy outcomes.

Postoperative Echography for Optimization of Radiation Dosimetry in Patients with Uveal Melanoma Treated with Plaque Brachytherapy

PURPOSE

(1) To describe the technique of postoperative echography to confirm the intended treatment dose to the tumor apex in patients with uveal melanoma treated with plaque brachytherapy. (2) To describe the local tumor control rate and visual outcomes with the brachytherapy strategies used at our institution.

DESIGN

Retrospective review.

SUBJECTS

Three hundred and seventy-two consecutive patients with uveal melanoma (small, medium, and large) treated with plaque brachytherapy at the University of Iowa from August 2008 to February 2019.

METHODS

Patient demographics and tumor characteristics were recorded for each patient. Patients with posterior tumors treated with plaque brachytherapy (n = 355) underwent intraoperative ultrasound to confirm plaque placement, and additional postoperative ultrasound on day 1 to 3 postplaque insertion. In cases where intratumor/episcleral plaque edema or hemorrhage shifted the dose to the prescription point to < 85 Gray (Gy), the duration of plaque brachytherapy was increased to compensate. Statistical analysis was performed to compare variables associated with the need for plaque adjustment.

MAIN OUTCOMES MEASURES

Variables associated with plaque dose needing to be recalculated, local tumor control, and visual acuity outcomes.

RESULTS

In 31 (8.3%) cases, postoperative echography showed that the tumor apex had shifted outside the 85 Gy isodose curve, requiring adjustment of the duration of brachytherapy (28 cases) or repositioning of the plaque (3 cases). Collaborative Ocular Melanoma Study tumor size was significantly associated with need to adjust the plaque prescription dose (P = 0.03), with large tumors having the highest rate of adjustment. Tumor thickness was larger in cases requiring plaque adjustment compared with those that were not adjusted (median 4.9 mm vs. 3.0 mm, P < 0.01). Local tumor control was 99% (95% confidence interval, 97%-100%) at 5 years and 99% (95% confidence interval, 97%-100%) at 10 years. The percentage of patients who had experienced a visual acuity decline of ≥ 3 lines of vision or had < 20/200 acuity was 14.9% at 1 year after brachytherapy, 35.3% at 3 years, and 51.6% at 5 years.

CONCLUSIONS

Postoperative ultrasound performed on postoperative day 1 to 3 after plaque insertion for patients undergoing brachytherapy for uveal melanoma may result in improved local tumor control, particularly in the setting of thicker or larger tumors.

Design and optimizing a novel ocular plaque brachytherapy with dual-core of 103Pd and 106Ru

In recent decades, eye plaques of brachytherapy have been extensively used as primary treatment as well as a complementary treatment for ocular cancer. The purpose of this study is the development of the eye plaque brachytherapy throughout a new design of eye plaque by combining the COMS plaque and the CCB BEBIG plaque loaded by IRA1-¹⁰³Pd and ¹⁰⁶Ru, respectively. A new dual-core plaque with a diameter of 20 mm was designed in the way that the BEBIG plaque with a diameter of 20 mm loaded by ¹⁰⁶Ru plate is attached to the COMS plaque with a diameter of 20 mm loaded by 24 of IRA1-¹⁰³Pd seeds. Dose calculations for the new plaque were performed by using the MCNP5 code. Dose calculations of dual-core plaque including ¹⁰³Pd seeds (gamma) and ¹⁰⁶Ru plate (beta) were separately done for the sake of MCNP constraints in gamma and beta particle transfer simultaneously. The new dual-core plaque delivers a much higher dose rate to the tumor compared with every single plaque, while the dose rate reached to healthy tissues is slightly higher than each plaque separately. Of course, this is acceptable because the treatment time reduces and subsequently the error in radiation therapy reduces.

[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.

Regression patterns of choroidal melanoma: After palladium-103 (103Pd) plaque brachytherapy

Purpose:

To describe the patterns of regression of choroidal melanoma after treatment with plaque brachytherapy.

Methods:

Retrospective interventional case series including 170 consecutive patients treated with ¹⁰³Pd eye plaque radiation for choroidal melanoma. Outcome measures were changes in tumor thickness, surface characteristics, tumor vascularity, ultrasonography, fluorescein angiography, optical coherence tomography, and histopathology.

Results:

The mean initial tumor thickness was 3.9 mm (median 2.8 mm; range 2–11.3 mm) that decreased to 1.7 mm (median 1.2 mm; range 0–7.1 mm) after plaque brachytherapy. On imaging, tumors were pigmented in 51% (n = 86/170), amelanotic in 10% (n = 17/170), and variably pigmented in 39% (n = 67/170). Tumor pigmentation increased in 64% (n = 106/166), decreased in 18% (n = 30/166), and was unchanged in 18% (n = 30/166). Of the 120 that demonstrated intrinsic vascularity, 10% (n = 12/120) had decreased tumor-related vascularity and 90% (n = 108/120) showed complete resolution. Subretinal fluid was present in 34% (n = 58/170) of eyes at presentation. Of them, 15% (9; n = 9/58) had persistent SRF at last follow-up. On ultrasound imaging, 88% (n = 149/170) tumors presented with low to moderate internal reflectivity of which 61% (n = 91/149) showed increased reflectivity on regression. We noted a crescendo–decrescendo fluctuation in the presence of orange pigment lipofuscin along with complete resolution of drusenoid retinal pigment epithelial detachments. In the entire series of 170 patients, there was 0.5% (1) failure of local control, 2% (4) secondary enucleations, and 6% (10) patients developing metastasis.

Conclusion:

Findings related to choroidal melanoma regression after ¹⁰³Pd plaque brachytherapy included decreased intrinsic tumor vascularity, decreased tumor-related subretinal fluid, increased pigmentation, specific changes in orange pigment lipofuscin and resolution of drusenoid retinal pigment epithelial detachments, as well as decreased tumor thickness with an increase in internal reflectivity on ultrasound.

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

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

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

Patterns of care and survival outcomes after treatment for uveal melanoma in the post-coms era (2004-2013): a surveillance, epidemiology, and end results analysis

PURPOSE

The Collaborative Ocular Melanoma Study (COMS) established modern treatment recommendations for uveal melanoma. We aim to evaluate patterns of care and survival outcomes in the time after COMS.

MATERIAL AND METHODS

The retrospective study population includes 2,611 patients in the SEER database treated for uveal melanoma between 2004-2013. Patients stage were T1-4N0M0. Data analyzed included age, clinical stage, tumor size, race, and treatment. Treatments included enucleation (EN) and globe preserving therapy (GPT), which consisted of limited surgical resection or ablation (LSRA), external beam radiation (EBRT), or brachytherapy (BT). Patients treated with radiation may receive radiation therapy alone (RTA) or radiation therapy and supplemental laser therapy (RT+SLT). We evaluated disease specific survival (DSS) and overall survival (OS) using log-rank statistics, and Cox univariate and multivariate analysis.

RESULTS

The median follow-up was 44 months. Treatment strategy was EN in 538 (20.6%) patients, LSRA in 80 (3.1%), EBRT in 609 (23.3%), and BT in 1,384 (53.0%). 1,876 patients received RTA and 117 received RT+SLT. Enucleation was associated with inferior DSS and OS compared to GPT in multivariate analysis (MVA) (p < 0.01). Limited surgical resection or ablation and radiation had similar DSS and OS. Brachytherapy and EBRT had similar DSS and OS. Radiation therapy and supplemental laser therapy was associated with improved DSS compared to RTA in UVA (p = 0.03), but not MVA. The 5-year DSS for enucleation, RTA, and RT+SLT were 66.7%, 87.0%, and 94.7% (p < 0.01), respectively.

CONCLUSIONS

Globe preserving treatments such as limited surgery or radiation are commonly utilized alternatives to enucleation, and resulted in favorable survival outcomes. Additional research is required to compare the outcomes of the various globe preserving treatment strategies.

Uveal Melanoma: Current Trends in Diagnosis and Management

Uveal melanoma, which is the most common primary intraocular malignancy in adults, arises from melanocytes within the iris, ciliary body and choroid. The diagnosis is based principally on clinical examination of the tumor with biomicroscopy and indirect ophthalmoscopy and confirmed by diagnostic techniques such as ultrasonography, fundus fluorescein angiography and optical coherence tomography. The clinical diagnosis of posterior uveal melanomas can be made when the classical appearance of a pigmented dome-shaped mass is detected on dilated fundus exam. Uveal melanomas classically show low to medium reflectivity on A-scan ultrasonography and on B-scan ultrasonography the tumor appears as a hyperechoic, acoustically hollow intraocular mass. Management of a suspicious pigmented lesion is determined by its risk factors of transforming into a choroidal melanoma, such as documentation of growth, thickness greater than 2 mm, presence of subretinal fluid, symptoms and orange pigment, margin within 3 mm of the optic disc, and absence of halo and drusen. Advances in the diagnosis and local and systemic treatment of uveal melanoma have caused a shift from enucleation to eye-conserving treatment modalities including transpupillary thermotherapy and radiotherapy over the past few decades. Prognosis can be most accurately predicted by genetic profiling of fine needle aspiration biopsy of the tumor before the treatment, and high-risk patients can now be identified for clinical trials that may lead to target-based therapies for metastatic disease and adjuvant therapy which aims to prevent metastatic disease.

Treatment of primary intraocular melanoma

The treatment of intraocular melanoma has evolved recently. Enucleation has been superseded largely by brachytherapy, proton beam radiotherapy, stereotactic irradiation, trans-scleral local resection, transretinal resection and diode laser phototherapy. Many patients develop metastatic disease, which usually involves the liver and occurs hematogenously. Disseminated disease rarely responds to therapy, and is usually fatal within 1 year of the onset of symptoms. Uveal melanomas develop characteristic chromosomal abnormalities, such as loss of chromosome 3. This is associated with a reduction in the 5-year survival from approximately 95% to less than 50%.

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.

Expression of 12 cytokines in aqueous humour of uveal melanoma before and after combined Ruthenium-106 brachytherapy and transpupillary thermotherapy

PURPOSE

To determine the aqueous humour levels of 12 cytokines in eyes with uveal melanoma and whether their expression changes after combined Ru-106 brachytherapy and transpupillary thermotherapy (TTT).

METHODS

Aqueous humour samples were collected from 20 patients with previously untreated uveal melanoma undergoing combined Ru-106 brachytherapy and TTT, both at the time of plaque placement and removal. Using multiplex biochip array technology, 12 different cytokines were measured, including interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor (VEGF), tumour necrosis factor (TNF)-α, interferon (IFN)-γ, epidermal growth factor (EGF) and monocyte chemoattractant protein (MCP)-1. Aqueous humour from 20 patients undergoing cataract surgery was used as control.

RESULTS

IL-6, IL-8, IFN-γ and MCP-1 were highly expressed in uveal melanoma, whereas IL-2, IL-10 and TNF- α were low in expression. There was a positive correlation between tumour height and IL-8 level (p = 0.020). Vascular endothelial growth factor tends to be highly expressed in melanoma-containing eyes (p = 0.056). Levels of IL-6, IL-8 and IL-1β increased after the mean 117 ± 38 hrs of brachytherapy and adjunctive TTT with a tumour apex dose of 61 ± 28 Gy and a scleral contact dose of 786 ± 226 Gy. Increase in levels of IL-6 (p = 0.003) and IL-8 (p = 0.046) positively correlated with scleral contact dose.

CONCLUSIONS

Cytokines such as IL-6, IL-8, IFN-γ and MCP-1 may be implicated in the progression of uveal melanoma. Ocular irradiation from a Ru-106 plaque promoted an increase in the levels of IL-6, IL-8 and IL-1β, modulation of which could be useful in managing radiation-related side effects.

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.

Changes in immunological markers and influx of macrophages following trans-scleral thermotherapy of uveal melanoma

PURPOSE

In trans-scleral thermotherapy (TSTT), heat is applied through the sclera in order to target an intraocular uveal melanoma. Previously, it had been shown that in uveal melanoma, hyperthermia and transpupillary thermotherapy influenced expression of immunologically relevant proteins, such as S100, HLA and heat-shock proteins (HSPs). We investigated whether TSTT induced similar changes.

METHODS

Experimental TSTT was applied on eleven uveal melanomas prior to enucleation. Each tumour sample was processed for histopathological examination; immunohistochemical analysis was performed to determine expression of S100, HLA, HSPs and macrophage markers.

RESULTS

In TSTT-treated areas, expression of S100 and different HSPs was lost, while an upregulated expression of HSP GP96 was observed at the border of these areas. Expression levels of HLA-A and HLA-B varied between tumours and were not influenced by TSTT. The borders of the TSTT-treated areas showed high numbers of infiltrating macrophages, which were predominantly of the M2 phenotype.

CONCLUSION

TSTT has an effect on immunological parameters with local loss of expression of HSPs and S100. The influx of M2 macrophages around the TSTT-treated areas indicates the presence of an innate immune reaction against the induced necrosis, suggesting that TSTT-treated tumour cells are removed by a macrophage-mediated tissue repair mechanism.

Triamcinolone acetonide and anecortave acetate do not stimulate uveal melanoma cell growth

PURPOSE

Radiotherapy-induced radiation retinopathy can develop in over 40% of eyes treated for uveal melanoma. Triamcinolone acetonide (TA) and anecortave acetate (AA) can be used to treat radiation retinopathy. It is not known whether TA or AA has any effect on potentially still viable uveal melanoma cells in the choroid after radiotherapy. We therefore studied the effect of these drugs on the proliferation of uveal melanoma cell lines in vitro. Furthermore, as these drugs are supposed to counteract vascular leakage, we determined their effect on the expression and production of the proangiogenic vascular endothelial growth factor-A (VEGF-A), the antiangiogenic pigment epithelium-derived factor (PEDF), and thrombospondin-1 (TSP-1) in uveal melanoma cells.

METHODS

Three uveal melanoma cell lines were treated in vitro with TA or AA. Cell proliferation was measured by counting cells and using the Water-Soluble Tetrazolium Salt-1 (WST-1) assay. VEGF-A and PEDF production was measured by ELISA, and intracellular expression of angiogenic-associated genes including VEGF-A, PEDF, and TSP-1 was determined by real-time quantitative RT-PCR.

RESULTS

We found no effect of TA or AA on tumor cell growth or production of VEGF-A and PEDF in any of the three uveal melanoma cell lines tested. Regarding expression as measured by RT-PCR, TA had an inhibiting effect on TSP-1 in only one cell line, and no effect on VEGF-A or PEDF. AA showed a similar lack of effect.

CONCLUSIONS

Since TA and AA do not stimulate uveal melanoma cell growth, it seems to be safe to use these drugs to treat radiation retinopathy after irradiation for uveal melanoma. Additional experiments using more cell lines or primary tumor cell cultures are needed to validate this conclusion. Furthermore, the results of our study suggest that TA does not exert its antileakage effect through downregulation of VEGF-A or upregulation of TSP-1 or PEDF in uveal melanoma cell lines. It is possible that TA and AA influence these pro- and antiangiogenic factors only under hypoxic circumstances. Further investigation is needed.

Modelling the impact of blood flow on the temperature distribution in the human eye and the orbit: fixed heat transfer coefficients versus the Pennes bioheat model versus discrete blood vessels

Prediction of the temperature distribution in the eye depends on how the impact of the blood flow is taken into account. Three methods will be compared: a simplified eye anatomy that applies a single heat transfer coefficient to describe all heat transport mechanisms between the sclera and the body core, a detailed eye anatomy in which the blood flow is accounted for either by the bioheat approach, or by including the discrete vasculature in the eye and the orbit. The comparison is done both for rabbit and human anatomies, normo-thermally and when exposed to homogeneous power densities. The first simplified model predicts much higher temperatures than the latter two. It was shown that the eye is very hard to heat when taking physiological perfusion correctly into account. It was concluded that the heat transfer coefficient describing the heat transport from the sclera to the body core reported in the literature for the first simplified model is too low. The bioheat approach is appropriate for a first-order approximation of the temperature distribution in the eye when exposed to a homogeneous power density, but the discrete vasculature down to 0.2 mm in diameter needs to be taken into account when the heterogeneity of the temperature distribution at a mm scale is of interest.

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

BACKGROUND

To determine the effectiveness and risk profile of combined ruthenium- (Ru)-106-brachytherapy and transpupillary thermotherapy (TTT) of the tumour apex for the treatment of large choroidal melanoma.

METHODS

A consecutive series of 31 large choroidal melanoma treated by Ru-106-brachytherapy and adjuvant TTT was studied. TTT was performed 1 day prior to plaque removal and up to 3 times (mean: 1.8) during follow-up. Evaluation comprised tumour regression, treatment-related adverse events, necessity of additional treatment and visual results.

RESULTS

Mean follow-up was 21.6+/-7.8 (10.8-38.3) months. Mean tumour thickness was 6.8+/-1.0 (5.0-8.9) mm prior to treatment. Mean residual tumour thickness at the end of follow-up was 2.5+/-1.0 mm. Relevant adverse treatment effects were exudative maculopathy or macula oedema (22.6%), vitreous haemorrhage (16.1%), optic neuropathy (16.1%) and retinal detachment (9.7%). One tumour recurrence occurred during follow-up, and was treated by enucleation.

CONCLUSIONS

The combination of Ru-106-brachytherapy with TTT allows for the treatment of large posterior choroidal melanoma. The rate of treatment-related adverse events appears to be acceptable.

Transpupillare Thermotherapie (TTT) von Aderhautmelanomen

BACKGROUND

An increasing number of orbital recurrences after TTT have been reported; the aim of our paper was to present our long-term results after a maximum follow-up of 8 years and 2 months.

PATIENTS AND METHOD

Among 18 eyes, 10 tumors were classified as small, and 8 as medium sized (with a maximum prominence of 5.6 mm): 5 melanomas had a juxtapapillary location, 6 a macular (or juxtamacular) location, and 7 were located in the midperiphery of the fundus.

RESULTS

After a median follow-up of 7 years in seven tumors a complete regression (scar formation) could be achieved, and in six a partial regression (with a maximum residual prominence of 2.9 mm) could be seen. In three patients a recurrence was treated either by another TTT or a Ruthenium-106 plaque; in another two recurrences, enucleation had to be performed. In none of the cases has an orbital recurrence occurred so far.

CONCLUSION

To prevent recurrences, adequate technique and appropriate selection of patients are mandatory in our opinion (no tumors higher than 3 mm). The higher the tumor prominence, the greater the chance of recurrences. Amelanotic melanomas and macular melanomas seem to respond poorly to thermotherapy.

Local tumor control after 106Ru brachytherapy of choroidal melanoma

PURPOSE

To report on local tumor control after (106)Ru brachytherapy for choroidal melanoma.

METHODS AND MATERIALS

A total of 458 patients with choroidal melanoma were treated at a single institution between January 1993 and December 2001. The tumors had a median longest basal dimension of 10.6 mm and a median height of 3.2 mm. The brachytherapy was administered using a 15- or 20-mm plaque. For posterior tumors, the plaque was positioned eccentrically with its posterior edge aligned with the posterior tumor margin to reduce the radiation dose to the optic disk and fovea. A minimal scleral dose sufficient to cause visible choroidal atrophy provided a permanent ophthalmoscopic record of the distribution of choroidal irradiation. If radiotherapy to the posterior tumor was uncertain, adjunctive transpupillary thermotherapy was administered 6 months postoperatively.

RESULTS

The actuarial rates of tumor recurrence were 1%, 2%, and 3% at 2, 5, and 7 years, respectively. Local tumor recurrence correlated with the longest basal tumor dimension (Cox univariate analysis, p = 0.02, risk ratio 1.41, 95% confidence interval 1.06-1.88). Seven of the nine eyes with recurrent tumor were salvaged with additional conservative therapy.

CONCLUSION

The low rate of local tumor recurrence suggests that ruthenium plaque radiotherapy is effective with good case selection and if special measures are taken to ensure that the plaque is positioned correctly.

Visual acuity after Ruthenium106 brachytherapy of choroidal melanomas

PURPOSE

To report on conservation of visual acuity after Ruthenium(106) (Ru-106) brachytherapy of choroidal melanoma.

METHODS AND MATERIALS

This study was a noncomparative interventional case series of 458 patients with choroidal melanoma treated at a single center between January 1993 and December 2001. The intervention consisted of Ru-106 brachytherapy delivering minimum scleral and apex doses of 300 Gy and 80 Gy, respectively, using a 15-mm or 20-mm plaque. For discrete, posterior tumors, the plaque was positioned eccentrically with its posterior edge aligned with the posterior tumor margin. To ensure correct plaque positioning, any overlying extraocular muscles were dis-inserted, and the locations of both tumor and plaque edges were confirmed by transillumination and indentation. The main outcome measures were conservation of vision of 20/40 or better, 20/200 or better, and Counting Fingers or better, according to baseline variables.

RESULTS

The actuarial rate of conservation of 20/40 or better was 55% at 9 years, loss of such vision correlating with posterior tumor extension (p < 0.001), temporal tumor location (p = 0.001), increased tumor height (p = 0.01), and older age (p < 0.01) (Cox multivariate analysis). Similar analyses showed conservation of 20/200 or better in 57% of eyes at 9 years, loss correlating with reduced initial visual acuity (p < 0.001), posterior tumor extension (p < 0.001), and temporal tumor location (p = 0.006). Counting Fingers or better vision was conserved in 83% of patients at 9 years, loss correlating with increased tumor height (p < 0.0001). Local tumor recurrence occurred in 9 patients (actuarial rate, 3% at 9 years).

CONCLUSION

Ruthenium(106) brachytherapy of posterior choroidal melanoma achieves good conservation of vision if the tumor does not extend close to the optic nerve or fovea.

Transscleral thermotherapy with laser-induced and conductive heating in hamster Greene melanoma

The purpose of this study was to investigate the cytotoxic effect of heat as induced by transscleral thermotherapy (TSTT), which may be of interest in the treatment of patients with choroidal melanoma. The aim of TSTT is to heat both the sclera and the tumor up to a cytotoxic temperature of about 60 degrees C. TSTT was performed in hamsters with subcutaneously implanted Greene melanoma covered by a specimen of human donor sclera of thickness 0.5, 0.7 or 0.9 mm. A newly developed applicator, which combines conductive episcleral heating at 60 degrees C with laser-induced heating, was used at laser powers ranging from 500 to 1500 mW delivered by an 810 nm diode laser, beam diameter 3 mm, and exposure time 1 min. Temperatures were measured at the scleral surface and at the sclera-tumor interface. The extent of tumor necrosis was examined by light microscopy and the sclera was examined by polarized light microscopy. Maximal depth of tumor necrosis without scleral damage was 4.4 (SD 1.5) mm. The temperature at the scleral surface after TSTT was 58.8 (SD 2.4) degrees C. The temperature at the sclera-tumor interface ranged from 56.4 (SD 3.7) degrees C at 500 mW to 65.3 (SD 4.4) degrees C at 1250 mW laser power. Structural changes to the scleral collagen started to develop at 1250 mW. TSTT with combined laser-induced and conductive heating caused cytotoxic temperatures in the tumor and the sclera, which were well tolerated by the scleral collagen.