Almuth M Koehler

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The first 128 consecutive patients with uveal melanomas treated with proton beam irradiation were studied in order to evaluate survival and visual acuity status of patients with relatively long-term follow-up. The median follow-up was 5.4 years, and no patient was lost to follow-up. All tumors showed regression. The most recent visual acuity was 20/40 or(More)
Proton irradiation was used in the treatment of uveal melanomas in 36 eyes. The average follow-up period was 16 months. One patient developed metastatic disease and died. No eye has been enucleated and tumor regression has been observed in all 22 eyes with a follow-up of more than 12 months. This type of treatment offers definite advantages over previously(More)
Methods for obtaining flattened charged-particle dose distributions over large areas are described. The system being used at Harvard for proton radiotherapy is discussed in detail. It is an extension of usual multiple-scattering techniques to include blocking out some of the central peak, followed by rescattering to fill in the profile, resulting in flat(More)
The incidence of metastasis and prognostic factors for metastasis in 780 consecutive patients with uveal melanomas treated with proton beam irradiation were evaluated. Metastasis developed in 64 patients (8%). The median time from treatment to the diagnosis of metastasis was 2.1 years (range, 3 months to 7.3 years). The liver was primarily involved in 58(More)
Proton beam irradiation was used in the treatment of 76 uveal melanomas from July 1975 to December 1980. Five (7%) were small, 32 (42%) were medium, and 39 (51%) were large melanomas. The follow-up period ranged from two months to 5 1/2 years; 19 patients were followed up for more than two years and 39 were observed for more than a year. Tumor regression(More)
A 160-MeV proton beam has been modified to irradiate patients with localized tumors by using convention treatment schedules. This proton beam has the physical advantage of megavoltage x-rays of reducing the radiation dose to normal tissues adjacent to the tumor volume. A perineal proton technique used as boost therapy (2,000 to 2,500 rads) was evaluated in(More)
The design, construction and calibration of a convenient irradiator is described that provides controlled exposure to a uniform external source of well-characterized alpha particles at a dose-rate of 0.99 cGy min-1. The use of a precis- ion photographic shutter allows the accurate delivery of doses as low as 0.01 mGy (1 mrad) to cultured cells. Special(More)
Proton-beam radiation therapy has been developed for the treatment of chordomas or sarcomas of bone or soft tissue that abut the central nervous system. The authors report the results of treatment of 10 patients, six with chordoma, three with chondrosarcoma, and one with a neurofibrosarcoma. Local control has been achieved for all patients (with, however,(More)