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J L Bosworth

Publications and source records attributed to J L Bosworth.

14 recordsLinked to original sources
PubMed1996

Radiotherapy for age-related macular degeneration: preliminary results of a potentially new treatment.

PURPOSE: Neovascular macular degeneration is the leading cause of severe blindness in North America today. Limited treatments are available for this disease process. A Phase I/II study was performed to determine the toxicity and efficacy of external beam radiotherapy in patients with age-related subfoveal neovascularization. METHODS AND MATERIALS: Between March 1994 and June 1995, 52 patients with a mean age of 80 (60-92) were enrolled. These patients were either not eligible or were poor candidates for laser photocoagulation, primarily because of the subfoveal location of the neovascularization. Initial visual acuities ranged from 20 out of 32 to finger counting at 3 feet. All patients underwent fluorescein angiographic evaluation and documentation of their neovascular disease prior to irradiation. Patients were treated with a single lateral 4- or 6-MV photon beam, to a dose of 14-15 Gy in eight fractions over 10 days. The field size averaged 5 x 3 cm. RESULTS: No significant acute morbidity was noted. All patients underwent ophthalmic examinations and repeat angiography at 1 and 3 months posttreatment and then at 3-month intervals. With a mean follow-up of 7 months (3-18 months), 41 patients (79%) are within two lines of their pretreatment visual acuity. On angiographic imaging, there was stabilization of subfoveal neovascular membranes in 34 patients (65%). New neovascular membranes have been noted in five patients. CONCLUSIONS: It appears that radiotherapy can affect active subretinal neovascularization, but it is unlikely to prevent new neovascular events produced by this chronic disease. Further investigation is warranted.

Aged↗
PubMed1996

Radiation therapy for subretinal neovascularization.

PURPOSE: To evaluate low-dose external beam irradiation and plaque radiotherapy for the treatment of subretinal neovascularization. METHODS: The authors treated 137 patients with radiation therapy for subretinal neovascularization. Herein, they examine a subset of 75 patients with exudative age-related macular degeneration who were treated with (4- or 6-MV photons) external beam irradiation at a dose of 1200 to 1500 cGy to the affected macula. In addition, six patients were treated with palladium 103 ophthalmic plaque brachytherapy to an equivalent retinal apex dose of 1200 to 1500 cGy. The authors compared the intralesional, intraocular, and intracranial radiation dose distributions of each treatment modality. Early Treatment Diabetic Retinopathy Study-type visual acuity determinations, ophthalmic examinations, and angiography were performed before and after treatment. Clinical evaluations were performed in a nonrandomized and unmasked fashion. RESULTS: Episcleral plaque brachytherapy was found to provide a higher average radiation dose within the neovascular tissues while delivering less radiation to most normal ocular (both eyes) and all intracranial structures. Both forms of radiotherapy were associated with decreased hemorrhages, exudates, and leakage of neovascular membranes. Ten (13 percent) patients receiving external beam radiotherapy had transient epiphora and ocular irritation. CONCLUSION: Observation and laser photocoagulation of subfoveal neovascularization have been associated with poor visual outcomes. Pilot experience suggests that low-dose radiotherapy offers a method to treat subretinal neovascularization without destroying the overlying retina. Although the authors' radiation distribution studies favored plaque radiotherapy, additional factors such as relative efficacy, expense, convenience, and safety must be investigated.

Aged↗
PubMed1994

Palladium 103 plaque radiotherapy for uveal melanoma. Clinical experience.

PURPOSE: To evaluate the effect of palladium 103(103Pd) ophthalmic plaque brachytherapy on patients with uveal melanoma. BACKGROUND: Radioactive 103Pd seeds have become available for plaque brachytherapy, and computer-aided simulations have compared the intraocular dose distribution of 103Pd versus iodine 125 (125I) plaques in patients with uveal melanoma. The use of the lower-energy radionuclide 103Pd increased the radiation to the tumors and decreases irradiation of most normal ocular structures. METHODS: The authors have begun a phase 1 clinical trial evaluating the effect of 103Pd ophthalmic plaque radiotherapy on intraocular tumors. Uveal melanoma was diagnosed, and the patients were found to be negative for metastatic disease. All patients were given one 103Pd radioactive plaque treatment, and six patients also were given adjuvant microwave hyperthermia. RESULTS: Palladium 103 ophthalmic plaque radiotherapy was used to treat 23 patients with uveal melanoma. Patients were followed for up to 27 months (mean, 13.5 months). One eye was enucleated for progressive tumor enlargement (4 months after treatment). One patient died (of metastatic melanoma). Eight patients have lost greater than two lines of visual acuity, one has gained more than two lines. Fifteen patients (65%) were within two lines or had better than their preoperative visual acuity. Relating to the effect of treatment on visual acuity, 15 (65%) tumors were located equal to or less than 2 mm from the fovea. CONCLUSION: Palladium 103 ophthalmic plaque radiotherapy was noted to control the growth of uveal melanomas. Compared with other forms of plaque radiotherapy at this follow-up interval, the authors have noted no new complications, no difference in local control, and/or changes in tumor response to treatment. More long-term follow-up will be required to demonstrate differences between 125I and 103Pd ophthalmic plaque brachytherapy.

Brachytherapy↗
PubMed1993

Palladium-103 versus iodine-125 for ophthalmic plaque radiotherapy.

PURPOSE: A dosimetry study comparing the use of I-125 vs. Pd-103 radioactive seeds for ophthalmic plaque brachytherapy. METHODS AND MATERIALS: Palladium-103 (Pd-103) seeds in ophthalmic plaques were used to treat 15 patients with intraocular malignant melanoma. Computer-aided simulations were performed to evaluate the intraocular dose distribution of I-125 versus Pd-103 ophthalmic plaques (delivering equivalent apex doses). Seven target points were selected. Starting at the outer scleral surface, four were located along the central axis of the plaque: the 1 mm point (the inner sclera), the 6 mm point, the tumors apex, and the opposite eye wall. We also evaluated the fovea, optic nerve, and the lens because they were considered to be critical structures. RESULTS: These studies demonstrated that the lower energy photons generated by Pd-103 seeds (average 21 KeV) in ophthalmic plaques were more rapidly absorbed in tissue than photons generated by I-125 (average 28 KeV). Therefore, during ophthalmic plaque radiotherapy, Pd-103 photons were found to be more rapidly absorbed within the tumor and less likely to reach most normal ocular structures. On average, the use of Pd-103 decreased the dose to the fovea by 5.7%, to the optic nerve by 8.4%, to the lens by 26%, and to the opposite eye wall by 38.4%. CONCLUSION: Palladium-103 ophthalmic plaque brachytherapy resulted in slightly more irradiation of the tumor and less radiation to most normal ocular structures.

Brachytherapy↗
PubMed1989

Thermoradiotherapy of choroidal melanoma. Clinical experience.

Thermoradiotherapy (TRT) was used to treat 18 patients with choroidal melanoma. Techniques and clinical observations using a plaque-type device capable of delivering microwave hyperthermia to intraocular tumors are described. Iodine-125 plaque irradiation (48-88 Gy to apex), together with microwave hyperthermia (46 degrees-52.5 degrees C to base), were given to patients during one brachytherapy session. Since October 1985, 15 medium and 3 large-sized tumors were treated. Clinical observations include partial clearing of six vitreous opacities as well as three retinal detachments noted before treatment. Objective measurements of improved visual acuity were noted in seven of the nine cases. All tumors responded to treatment, but one tumor had regrowth and the eye was enucleated. These data suggest that a microwave plaque can be used to deliver hyperthermia to human choroidal melanomas. Within the range of the follow-up period, no side effects that might preclude the use of this hyperthermia system for choroidal melanoma treatment were noted.

Choroid Neoplasms↗
PubMed1988

Choroidal melanoma: I-125 plaque therapy.

An iodine-125 eye plaque was used to treat 58 patients with choroidal melanoma. Patients were followed up for a mean of 48.7 months. Fifty patients had medium-sized lesions (height between 3.1 and 8.0 mm and base diameter less than 16.0 mm), and six patients had large lesions. There were 24 lesions less than 3.0 mm from the optic nerve. The average radiation dose to the apex of the tumor was 8,468 cGy (dose rate, 71 cGy per hour). Initial local disease control was achieved in 50 patients (86.2%). One patient with local treatment failure received another plaque treatment, which controlled disease, so the total disease control rate was 87.9%. Only eight patients died of their disease. Complications were similar to those with other treatment methods, but none of the patients in this study developed optic nerve atrophy.

Brachytherapy↗
PubMed1979

Possible nonspecific immunopotentiation by 2,4-dinitrochlorobenzene sensitization in patients with Hodgkin's disease.

Various immunological parameters were evaluated in untreated Hodgkin's patients before and after sensitization with dinitrochlorobenzene (DNCB). The ratio (r) of these parameters after/before DNCB sensitization for patients and second/first samples in the controls were calculated. There were significantly more patients in the r greater than 1.1 group for PHA and Con A responses and for peripheral blood T cell percentages. These data suggest that DNCB sensitization may have a nonspecific immunopotentiation effect.

Antibody Formation↗
PubMed1976

Delayed hypersensitivity and local control of patients treated by radiotherapy for head and neck cancer.

Delayed hypersensitivity of sixty-three patients with head and neck cancer treated by radiotherapy was correlated with short-term tumor control. Of eighteen patients with early disease, sixteen were DNCB-reactive and all were controlled and one of the two nonreactors was controlled. Thirty-three of forty-five patients with advanced tumors were reactive and nineteen were controlled. Only two of the twelve nonreactors were controlled.

Adult↗
PubMed1975

The effect of radial radiotherapy on delayed hypersensitivity and the inflammatory response.

Delayed hypersensitivity to DNCB and the inflammatory response to croton oil wereevaluated in 144 and 121 patients respectively, prior ro and 3 to 6 months following curative radiotherapy. Eighty-one patients had in vitri lymphocyte transformation by PHA;59 (41%) were nonreactors to DNCB and 27 (22%) to croton oil; 29 of 59 (49%) initiallyreactive became anergic. Similiar improvement of the inflammatory response was obtained. Patients who became DNCB-reactive following radiotherapy had the same favorable prognosis as those who were initially reactive. Radiotherapy did not adversely affect either delayed hypersensitivity or the inflammatory response. There was a 50% decrease in PHA stimulation and lymphocyte count after treatment. No correlation was found between DNCB reactivity and lymphocyte transfermation prior to or following radiotherapy. The evaluation of the effect of radiotherapy on cell-mediated immunity depends on the tests used.

Animals↗
PubMed1975

Delayed hypersensitivity in patients treated by curative radiotherapy. Its relation to tumor response and short-term survival.

Delayed hypersensitivity, as determined by skin reactivity to 2-4 dinitrochlorobenzene (DNCB), was tested in 112 patients prior to their undergoing curative radiotherapy. Of the strong DNCB reactors, 84% had an excellent radiation tumor response, while only 48% of the negative reactors had an equivalent response. Almost twice as many strong DNCB reactors were alive and free of disease (NED) at 6 months (70% vs. 38% for nonreactors). Similarly, the positive DNCB reactors had a median survival of 18 months, compared to 10 months for the nonreactors.

Adolescent↗
PubMed1975

Radiation-related eosinophilia. Correlation with delayed hypersensitivity, lymphocyte count, and survival in patients treated by curative radiotherapy.

Abdominal irradiation may produce eosinophilia. The relationship between radiation-related eosinophilia (RRE), reactivity to 2-4 dinitrochlorobenzene (DNCB), lymphocyte count, and prognosis was evaluated in 98 patients irradiated for tumors below the diaphragm. Forty-two per cent manifested RRE and 62% reacted to DNCB. Fifteen of 19 (79%) reactors who had RRE were disease-free at 6 months. Fourteen of 22 (64%) nonreactors who had RRE and 26 of 42 (62%) DNCB reactors without RRE were controlled. Fourteen of 15 (93%) nonreactors without RRE had disease at 6 months. Those who had RRE had double the median survival of those who did not.

Abdominal Neoplasms↗