Conformal episcleral plaque therapy

Radioactive plaque therapy for metastatic choroidal carcinoma

PURPOSE

To describe the outcome of radioactive episcleral plaque therapy for treatment of metastatic carcinoma to the choroid.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Five patients (six eyes) with carcinoma metastatic to the choroid.

METHODS

Retrospective review of the clinical records of five patients (six eyes) who underwent radioactive episcleral plaque therapy for choroidal metastases.

MAIN OUTCOME MEASURES

Tumor height, visual acuity, radiation optic neuropathy, and radiation retinopathy.

RESULTS

Radioactive episcleral plaque therapy resulted in shrinkage of the treated tumors and resolution of subretinal fluid in all eyes. After plaque treatment, best-corrected visual acuity was maintained within two lines of initial visual acuity for two eyes, decreased more than two lines for one eye, and improved more than two lines in three eyes. The treatment was well tolerated and there was no acute toxicity. Late complications included optic nerve atrophy (at 2 years) with proliferative radiation retinopathy (at 3 years) in one eye and optic atrophy (at 6 months) in another eye that had received prior external beam therapy.

CONCLUSIONS

In carefully selected cases, radioactive episcleral plaque therapy appears to be an effective and reasonable treatment for carcinoma metastatic to the choroid.

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.