Radiation therapy for macular degeneration: technical considerations and preliminary results.

PURPOSE: This study was undertaken to assess the toxicity and possible benefits from the administration of low-dose external-beam irradiation for Age-Related Macular Degeneration (ARMD). The premise of the treatment is that radiation induces regression and/or promotes inactivation of the subretinal neo-vasculature, resulting in reabsorption of fluid and blood thus reducing the risk for further leakage or bleeding, as well as subretinal fibrosis. Clinically, the beneficial effect could be translated into stabilization of visual acuity and prevention of progression of the wet type of ARMD with the possibility for some visual improvement. METHODS AND MATERIALS: Allegheny University Hospitals, Hahnemann, Department of Radiation Oncology, treated 278 patients prospectively beginning in January 1995 with low-dose irradiation for wet-type macular degeneration. Two hundred forty-nine patients were treated with a total dose of 14.40 Gy in eight fractions of 1.80 Gy over 10-13 elapsed days, and 27 patients with 20 Gy at 2 Gy per fraction over 12-15 days. The first two patients were treated to a total dose of 10.00 Gy in five fractions of 2.00 Gy. Patients were evaluated at 2-3 weeks and 2-3 months. A percentage (36.7%) of the patients had previously received laser treatments in the study eye, 21.9% once, 5% twice, 9.7% three or more. Subjective visual acuity and toxicity data was collected on all patients. RESULTS: At 2-3 weeks after treatment 195 patients (70%) retained their visual acuity without change, 68 patients (24.5%) stated they had improved vision, and 15 patients (4.8%) stated their vision continued to decrease. Two to 3 months after treatment, 183 patients (65.8%) had no change in their vision, 75 patients (27%) had an improvement in their vision, and 20 patients (7.2%) had a decrease in visual acuity. Transient acute reactions occurred in 14 of the 278 patients treated. CONCLUSION: Our observations in this group of 278 patients support the conclusion that many patients will have improved or stable vision after treatment with low-dose irradiation for age related wet type macular degeneration.

Epidermal growth factor receptor 425 monoclonal antibodies radiolabeled with iodine-125 in the adjuvant treatment of high-grade astrocytomas.

Fifty-nine patients with primary presentation of high-grade gliomas of the brain, 13 with astrocytomas with anaplastic foci and 46 with glioblastoma multiforme, were treated with surgical intervention and definitive postoperative radiation therapy followed by multiple intravenous administration of iodine-125-labeled monoclonal antibody-425, which binds specifically to human epidermal growth factor receptor. The total cumulative labeled antibody doses ranged from 40 to 296 mCi. The administration of the radiolabeled antibody was performed in most instances within 3 months following completion of the primary surgery and radiation therapy. No significant life-threatening toxicities were observed during the trial. At one year, 34 (58%) of the 59 patients in the trial were alive. The median overall survival for both groups was 13.5 months.

Radiation therapy in the treatment of pituitary adenomas.

Seventy-eight patients with pituitary adenomas were seen in the Department of Radiation Oncology at Hahnemann University between 1961 and 1986. Most were treated with megavoltage photons with or without prior surgery. In this group, 68 patients were followed: 39 were treated with radiation therapy (RT) alone, and 29 were treated with a combination of surgery and RT (S/RT). Patients were followed for 2 to 20 years. Of 68 patients, (97%) experienced complete response to treatment; 86% of the RT patients remained free of disease at 5 and 10 years. In the S/RT group, 100% and 94% remained free of disease at 5 and 10 years, respectively. Total disease-free survivals at 5 and 10 years were, respectively, 91% and 89%. The majority of the failures occurring in the RT group were with growth hormone-secreting tumors and Cushing's disease. Of the 7 patients that failed or recurred (time to recurrence: 1-16 years posttreatment), 6 have been followed: 4 were treated with surgery, 1 with RT, and 1 with S/RT. All 6 have remained free of disease since salvage, with 2- to 14-year follow-up periods. Serious morbidity and mortality have been reported previously with bitemporal field radiation using kilovoltage and low megavoltage RT. However, there was no temporal lobe necrosis or death in any of the patients in this study.