Plaque radiotherapy for juxtapapillary choroidal melanoma. Visual acuity and survival outcome

The American Brachytherapy Society recommendations for brachytherapy of uveal melanomas

PURPOSE

This article presents the American Brachytherapy Society (ABS) guidelines for the use of brachytherapy for patients with choroidal melanomas.

METHODS

Members of the ABS with expertise in choroidal melanoma formulated brachytherapy guidelines based upon their clinical experience and a review of the literature. The Board of Directors of the ABS approved the final report.

RESULTS

Episcleral plaque brachytherapy is a complex procedure and should only be undertaken in specialized medical centers with expertise in this sophisticated treatment program. Recommendations were made for patient selection, techniques, dose rates, and dosages. Most patients with very small uveal melanomas (<2.5 mm height and <10 mm in largest basal dimension) should be observed for tumor growth before treatment. Patients with a clinical diagnosis of medium-sized choroidal melanoma (between 2.5 and 10 mm in height and <16 mm basal diameter) are candidates for episcleral plaques if the patient is otherwise healthy and without metastatic disease. A histopathologic verification is not required. Small melanomas may be candidates if there is documented growth; some patients with large melanomas (>10 mm height or >16 mm basal diameter) may also be candidates. Patients with large tumors or with tumors at peripapillary and macular locations have a poorer visual outcome and lower local control that must be taken into account in the patient decision-making process. Patients with gross extrascleral extension, ring melanoma, and tumor involvement of more than half of the ciliary body are not suitable for plaque therapy. For plaque fabrication, the ophthalmologist must provide the tumor size (including basal diameters and tumor height) and a detailed fundus diagram. The ABS recommends a minimum tumor (125)I dose of 85 Gy at a dose rate of 0.60-1.05 Gy/h using AAPM TG-43 formalism for the calculation of dose. NRC or state licensing guidelines regarding procedures for handling of radioisotopes must be followed.

CONCLUSIONS

Brachytherapy represents an effective means of treating patients with choroidal melanomas. Guidelines are established for the use of brachytherapy in the treatment of choroidal melanomas. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose reporting policies. These guidelines will be modified as further clinical results become available.

Custom-designed plaque radiotherapy for nonresectable iris melanoma in 38 patients: tumor control and ocular complications

PURPOSE

To evaluate plaque radiotherapy for iris melanoma.

DESIGN

Prospective noncomparative interventional case series.

METHODS

For 38 patients, custom-designed plaque radiotherapy using iodine 125 isotope was applied overlying the cornea with a tumor apex dose of 80 Gy. The main outcome measures were tumor control and ocular complications using Kaplan-Meier estimates and Cox proportional hazards regression analysis.

RESULTS

In all cases, the melanoma was nonresectable owing to large or discohesive tumor. The tumor configuration was nodular in 24 cases (63%) and flat (diffuse) in 14 (37%). The mean tumor basal diameter was 9 mm (range 4 to 13 mm). Solid tumor extended into the anterior chamber angle in 36 eyes (95%). Tumor seeds were noted on the iris stroma for a mean of 7 clock hours and in the anterior chamber angle for a mean of 4 clock hours. Five-year follow up revealed tumor metastasis in 0% and tumor recurrence in 8% of patients. Visual acuity of 20/200 or worse was found in 16% at 5 years. Radiation-related complications at 5 years included corneal epitheliopathy (9%), cataract (70%), and neovascular glaucoma (8%). No patients developed corneal necrosis, scleral necrosis, retinopathy, or papillopathy. After treatment, the combined incidence of tumor-related and radiation-related elevated intraocular pressure at 5 years was 33%. Enucleation was necessary in 13% at 5 years, for tumor recurrence (n = 3) and patient preference (n = 1).

CONCLUSIONS

Plaque radiotherapy is a useful alternative to enucleation for eyes with nonresectable iris melanoma. Tumor control is 92% at 5 years, but related complications, especially cataract and elevated intraocular pressure, should be anticipated.

The COMS randomized trial of iodine 125 brachytherapy for choroidal melanoma: IV. Local treatment failure and enucleation in the first 5 years after brachytherapy. COMS report no. 19

OBJECTIVE

To describe the frequency and predictors of local treatment failure and enucleation after iodine 125 (I(125)) brachytherapy in patients with choroidal melanoma treated and followed up in a large randomized clinical trial.

DESIGN

Prospective, noncomparative, interventional case series within a randomized, multicenter clinical trial.

PARTICIPANTS

Patients enrolled in the Collaborative Ocular Melanoma Study (COMS) trial of enucleation versus brachytherapy between February 1987 and July 1998; tumors measured 2.5 to 10.0 mm in apical height and no more than 16.0 mm in longest basal dimension.

METHODS

I(125) brachytherapy was administered via episcleral plaque according to a standard protocol. Follow-up ophthalmic evaluations, including ophthalmic ultrasound and fundus photography, were performed according to a standard protocol at baseline, every 6 months thereafter for 5 years, and subsequently at annual intervals. Survival analysis methods were used to estimate the cumulative risk of postirradiation treatment failure and enucleation. Factors associated with treatment failure and enucleation of plaqued eyes were evaluated using Cox proportional hazards analysis.

MAIN OUTCOME MEASURES

Reports of enucleation and of local treatment failure, defined as tumor growth, recurrence, or extrascleral extension, derived from clinical reports based on echographic and photographic documentation.

RESULTS

As of September 30, 2000, 638 of the 650 patients randomized to brachytherapy and so treated had been followed up for 1 year or longer, and 411 had been followed up for at least 5 years. Sixty-nine eyes were enucleated during the first 5 years after brachytherapy, and treatment failure was reported for 57 eyes. The Kaplan-Meier estimate of proportion of patients undergoing enucleation by 5 years was 12.5% (95% confidence interval [CI], 10.0%-15.6%); the risk of treatment failure was 10.3% (95% CI, 8.0%-13.2%). Treatment failure was the most common reason for enucleation within 3 years of treatment; beyond 3 years, ocular pain was most common. Risk factors for enucleation were greater tumor thickness, closer proximity of the posterior tumor border to the foveal avascular zone, and poorer baseline visual acuity in the affected eye. Risk factors for treatment failure were older age, greater tumor thickness, and proximity of the tumor to the foveal avascular zone. Local treatment failure was associated weakly with reduced survival after controlling for baseline tumor and personal characteristics (adjusted risk ratio, 1.5; P = 0.08).

CONCLUSIONS

Local treatment failure and enucleation were relatively infrequent events after I(125) brachytherapy within the COMS. Treatment failure typically occurred early and was associated weakly with poorer survival. The COMS randomized trial documented the absence of a clinically or statistically significant difference in survival for patients randomly assigned to enucleation versus brachytherapy. This analysis documents the efficacy of brachytherapy to achieve sustained local tumor control and to conserve the globe.

Plaque radiotherapy for large posterior uveal melanomas (> or =8-mm thick) in 354 consecutive patients

OBJECTIVE

To assess treatment complications and tumor control after plaque radiotherapy for large posterior uveal melanomas measuring 8 mm or greater in thickness.

DESIGN

Prospective noncomparative interventional case series.

PARTICIPANTS

Three hundred fifty-four patients each of whom had a posterior uveal melanoma measuring 8 mm or greater in thickness treated with plaque radiotherapy.

MAIN OUTCOME MEASURES

The four endpoints included (1) poor final visual acuity (20/200 or worse), (2) enucleation, (3) local tumor recurrence, and (4) metastasis. The clinical data regarding patient features, tumor features, and radiation parameters were analyzed for their impact on the four main outcomes using Cox proportional hazards regression models.

RESULTS

Using Kaplan-Meier estimates, final visual acuity was poor in 57% at 5 years and 89% at 10 years follow-up. Using multivariate analysis, the most important risk factors for poor visual acuity included retinal invasion by melanoma, increasing patient age, iodine 125 (I(125)) isotope, and <2 mm distance to the optic disc. Treatment-related complications at 5 years included proliferative retinopathy (25%), maculopathy (24%), papillopathy (22%), cataract (66%), neovascular glaucoma (21%), vitreous hemorrhage (23%), and scleral necrosis (7%). Enucleation was necessary in 24% at 5 years and 34% at 10 years follow-up. Using multivariate analysis, the risk factors for enucleation included left eye, peripheral tumor margin anterior rather than posterior to the equator, increasing tumor thickness, and ruthenium 106 (Ru(106)) isotope. Using Kaplan-Meier estimates, local tumor recurrence was found in 9% at 5 years and 13% at 10 years follow-up. Using multivariate analysis, risk factors for tumor recurrence included Ru(106) radioisotope and ciliary body involvement with tumor. Tumor-related metastases were found in 30% at 5 years and 55% at 10 years follow-up. Using multivariate analysis, risk factors for metastases included inferotemporal meridian, anterior extension of the tumor to the iris root, increasing tumor base, and posterior margin < 2 mm from the optic nerve.

CONCLUSIONS

Plaque radiotherapy provided tumor control at 10 years in 87% of patients with selected large posterior uveal melanomas (>8 mm thick) that otherwise would have been managed with enucleation. The large intraocular mass and associated features and radiation complications led to poor visual acuity in most patients. At 10 years follow-up, enucleation was necessary in 34% of patients, and metastasis developed in 55% of patients.

Subretinal pigment dispersion following transpupillary thermotherapy for choroidal melanoma

PURPOSE

To report the case of a patient who developed considerable subretinal pigment/debris dispersion following transpupillary thermotherapy (TTT). This type of tumour response is extremely rare with this relatively new therapeutic modality.

METHODS

A 50-year-old man with a left juxtapapillary choroidal melanoma measuring 8 x 6 x 4.3 mm was treated with 810 nm diode laser TTT administered in two sessions. Spot size was 3 mm and the power setting was 450 mW.

RESULTS

Four months after the first treatment session, a considerable amount of pigment/debris was seen to have dispersed in the subretinal space, accumulating mainly in the macular area. Over a 12-month follow-up, the tumour showed progressive shrinkage without any change in the amount or location of the shed pigment/debris. No new tumour formation, recurrence or systemic metastases were detected.

CONCLUSION

Subretinal pigment/debris dispersion is an unusual complication after TTT and requires close follow-up. There has been no short-term compromise on the life or visual acuity of this patient.

Incidence of radiation retinopathy after high-dosage single-fraction gamma knife radiosurgery for choroidal melanoma

OBJECTIVE

To investigate the incidence and clinical findings of radiation retinopathy after single-fraction high-dose gamma knife radiosurgery for choroidal melanoma.

DESIGN

Retrospective noncomparative interventional case series.

PARTICIPANTS

Thirty-two patients with choroidal melanoma.

METHODS

Review of charts, color fundus photographs, and fluorescein angiograms of 32 choroidal melanoma patients after radiosurgery. All patients were treated with the Leksell gamma knife in one fraction with a marginal dose between 40 and 80 Gy (median, 50 Gy) and were followed for at least 24 months (or until enucleation because of complications secondary to radiation).

MAIN OUTCOME MEASURES

Any clinical feature of radiation retinopathy and neovascular glaucoma.

RESULTS

During a mean follow-up of 38 months (range, 6-81 months) we found radiation retinopathy in 84% of our patients. The most common findings in these patients were intraretinal hemorrhages with an incidence of 70%, macular edema and capillary nonperfusion in 63%, and hard exudates in 52% of the patients. Less common were microaneurysms in 30% and retinal neovascularization in 22%. The time of onset of the various radiation-associated retinal findings ranged between 1 and 22 months. Forty-seven percent of all patients developed neovascular glaucoma. In our study there was no correlation between radiation dosage applied and clinical findings.

CONCLUSIONS

Single-fraction high-dose Leksell gamma knife radiosurgery of choroidal melanomas with a median marginal dose of 50 Gy is highly associated with early radiation retinopathy and with neovascular glaucoma.

Primary transpupillary thermotherapy for small choroidal melanoma in 256 consecutive cases: outcomes and limitations

OBJECTIVE

The objective of this report was to evaluate ocular and systemic outcomes after primary transpupillary thermotherapy for choroidal melanoma and to identify the limitations of this treatment method.

DESIGN

Noncomparative interventional case series.

PARTICIPANTS

The participants included 256 patients with newly diagnosed choroidal melanoma.

MAIN OUTCOME MEASURES

The outcome measures included local tumor recurrence and visual acuity.

RESULTS

Before treatment, the mean tumor base was 7.1 mm, and mean tumor thickness was 2.7 mm. Overlying subretinal fluid was present in 215 cases (84%) and orange pigment on the tumor surface in 200 cases (78%). All tumors showed either photographic documentation of growth (114 cases; 45%) or substantial risk factors for growth (142 cases; 55%). After a mean of three treatment sessions, complete tumor control without recurrence was found in 232 cases (91%) and recurrence in 24 cases (9%). The mean time to recurrence was 22 months, and the mean recurrent tumor size was 3.8 mm base and 2.4 mm thick. Of the recurrent tumors, additional thermotherapy was successful in controlling 13 (5%), plaque radiotherapy in 8 (3%), and enucleation in 3 (1%). Using multivariable analysis, the risk factors for tumor recurrence included increasing number of thermotherapy sessions (reflecting less responsive tumor) (P = 0.0001) and optic disc overhung by tumor (P = 0.03). Kaplan Meier estimates revealed that 4% showed recurrence at 1 year, 12% at 2 years, and 22% at 3 years follow-up. When analyzing those 214 patients without multivariable risk factors for recurrence, Kaplan Meier estimates for recurrence were 2% at 1 year, 8% at 2 years, and 10% at 3 years. The visual acuity after treatment was 20/20 to 20/40 in 128 cases (50%), 20/50 to 20/100 in 47 (18%), and 20/200 or worse in 81 (32%). Using multivariable analysis, the most statistically significant factors at initial visit that were predictive of poor visual acuity (20/200 or worse) after treatment included documented tumor growth before treatment (P = 0.0001), mushroom tumor configuration (P = 0.002), initial symptom of blurred vision (P = 0.008), poor initial visual acuity (P = 0.005), superior quadrant tumor location (P = 0.03), underlying diabetes mellitus (P = 0.04), and optic disc overhung by tumor (P = 0.04). Tumor-related mortality occurred in two patients (1%), one of whom showed complete tumor regression to thermotherapy and the other with diffuse choroidal melanoma and local tumor margin recurrence.

CONCLUSIONS

Transpupillary thermotherapy is an effective treatment for certain small choroidal melanomas. Appropriate tumor selection is critical to successful treatment. Patients with tumors abutting or overhanging the optic disc or those requiring more than three sessions for tumor control are more likely to develop ultimate tumor recurrence. Transpupillary thermotherapy can cause damaging effects to the retina, leading to visual loss shortly after treatment.

Amelanotic choroidal nevus and melanoma: cytology, tumor size, and pigmentation as prognostic indicators

BACKGROUND

Choroidal nevi are fairly common lesions of the posterior pole that can sometimes transform into melanoma, and it is thought that most choroidal melanomas arise from preexisting nevi. Occasionally, these lesions present as nonpigmented or amelanotic variations of their pigmented counterparts. Recent studies suggest a relationship between tumor pigmentation and risk of growth and metastasis, with a better prognosis for lightly pigmented or amelanotic lesions.

CASE REPORTS

A case of an amelanotic choroidal nevus and melanoma are presented. In Case 1, a 26-year-old white female was found to have a large amelanotic nevus in the right eye. After 7 years of periodic observation, the lesion has not changed. In Case 2, a 51-year-old white male was diagnosed with a large amelanotic melanoma in the left eye. Due to extensive involvement of the optic nerve, the patient underwent enucleation. Histological evaluation confirmed the lesion as a mixed-cell type malignant amelanotic melanoma.

CONCLUSION

Management of choroidal nevi generally consists of periodic observation, and the most widely accepted management of choroidal melanoma is observation, radiotherapy, and transpupillary thermotherapy or enucleation. The therapeutic modality of choice for melanoma will vary depending on the size, growth, and location of the lesion. In addition, recent studies suggest an association between heavy tumor pigmentation, tumor size, cell type, and risk of metastasis. Although many variables will influence the final treatment option, pigmentation of the lesion should also be considered.

An automated approach to seed assignment for eye plaque brachytherapy

Episcleral plaques are commonly used for the treatment of ocular tumours such as choroidal melanoma. Treatment planning involves the assignment of seeds to slots on the plaque to achieve a desired dose rate distribution. Seed assignment is rather straightforward if seeds are ordered on demand. However, the assignment task becomes tedious and laborious if the seeds have to be chosen from an existing stock of seeds with different activities. To date, this task has usually been performed by a human planner through trial and error. An algorithm has been developed to automate the task of seed assignment using a mixed-integer programming method. We also explore ways to simplify the problem such that the method becomes practical in most facilities. We have tested the method on three randomly chosen clinical cases from our past records, to show that the algorithm could yield solutions within a shorter time frame and with less deviation from the desired dose rate distributions, as compared with the solutions from a human counterpart.

Stereotactic radiation therapy for malignant choroidal tumors: preliminary, short-term results

PURPOSE

To evaluate the role of stereotactic radiation therapy (SRT) in the treatment of malignant choroidal tumors.

DESIGN

Prospective, noncomparative case series.

PARTICIPANTS

Ten patients with unifocal choroidal metastasis (three lung carcinoma, three breast carcinoma, three colon carcinoma, one cutaneous melanoma) and five patients with primary choroidal melanoma underwent single-dose or fractionated SRT.

METHODS

Before treatment, computed tomography (CT) scans of the orbit were obtained with the patient wearing an individualized immobilization mask. An integrated macro-CCD-camera system viewed the eye for detection of movements. Three-dimensional computer-based treatment planning was carried out. Dose distribution was calculated and displayed in isodose lines on the CT data set. For SRT, a dedicated stereotactic linear accelerator (6 MV) was used. Total doses for choroidal metastases were 12 to 20 Gy in a single dose or 30 Gy over 10 days (3 Gy each session), and total doses for choroidal melanoma were 50 Gy over 5 or 10 days (10 or 5 Gy each session).

MAIN OUTCOME MEASURES

Best corrected visual acuity (ETDRS-chart), biomicroscopy, ultrasound examination, fluorescein angiography, and magnetic resonance imaging (MRI) were performed before treatment and at regular intervals after completion of SRT.

RESULTS

During a follow-up period from 1 to 34 months (median, 6.5 months), local tumor control was achieved in all eyes. A decrease in tumor size on ultrasonography or MRI was noted in eight patients. No persistent side effects were observed during follow-up.

CONCLUSIONS

Stereotactic radiation therapy allows steep dose gradients outside the target volume by minimizing the field of exposure. Thus only low radiation doses affect surrounding radiosensitive ocular structures. Our initial findings suggest that this technique may be effective in controlling tumor growth. Further studies are needed to compare treatment efficacy and safety with conventional treatment methods.

Radiation complications and tumor control after plaque radiotherapy of choroidal melanoma with macular involvement

PURPOSE

To determine the outcome of plaque radiotherapy in the treatment of macular choroidal melanoma and to identify the risk factors associated with the development of radiation complications, tumor recurrence, and metastasis.

METHODS

Chart analysis of 630 consecutive patients (630 eyes) with macular choroidal melanoma managed by plaque radiotherapy between July 1976 and June 1992.

RESULTS

The median largest basal tumor diameter was 10 mm, and the median tumor thickness was 4 mm. By means of Kaplan-Meier estimates, visually significant maculopathy developed at 5 years in 40% of the patients, cataract in 32%, papillopathy in 13%, and tumor recurrence in 9%. Vision decrease by 3 or more Snellen lines was found in 40% of the patients at 5 years. Sixty-nine eyes (11%) were enucleated because of radiation complications and recurrence. Twelve percent of the patients developed metastasis by 5 years and 22% by 10 years. Results of multivariate Cox proportional hazards analyses showed that the significant predictors for tumor recurrence were a distance of tumor margin from the optic disk of less than 2 mm (P = .003) and retinal invasion (P = .009). The significant variables that were predictive of metastasis included tumor thickness greater than 4 mm (P = .02) and largest basal tumor diameter greater than 10 mm (P = .03).

CONCLUSIONS

Plaque radiotherapy offers a 91% 5-year local tumor control rate for macular choroidal melanoma. Despite good local tumor control, the risk for metastasis is 12% at 5 years and 22% at 10 years. In 11% of the patients, enucleation eventually became necessary because of radiation complications and tumor recurrence.

Brachytherapy in primary ocular tumors

Patients with primary ocular tumors are seen infrequently in the medical profession, and most of these patients are referred to specialty centers which has resulted in a good study population. In the past, ocular tumors were treated with enucleation, but the current emphasis is now on organ preservation with sparing of all or partial visual acuity. In the management of these tumors, plaque brachytherapy and particle beam therapy have been used more frequently as an alternative to enucleation. A multi-institutional study, the Collaborative Ocular Melanoma Study (COMS), is currently underway, organized by the National Eye Institute. The COMS isotope of choice is Iodine-125 (I-125). Recurrence after plaque therapy is approximately 15%, although it may be as high as 37% at 15 years for metastatic disease. In one study, nondiffuse iris melanoma has been controlled in 93% of patients by custom plaques utilizing I-125. Plaque brachytherapy also utilizes I-125 for the treatment of retinoblastoma tumors either as primary therapy or following external beam radiation. Currently, through the utilization of plaque radiation therapy, enucleation may be avoided in the majority of patients, and many patients may retrieve some visual acuity. We will review plaque brachytherapy techniques, diagnosis, staging, and some of the pertinent literature of the two most frequently encountered primary ocular tumors: choroidal melanoma, sometimes referred to as uveal melanoma, with an incidence of approximately 1,500 new cases per year in the adult population; and retinoblastoma, the most common intraocular primary malignancy found in childhood, with a frequency of approximately 250 [corrected] new cases per year.