Magnus I. Smedal

Radiotherapy for Kaposi's sarcoma

Between 1954 and 1976, 60 patients with Kaposis sarcoma were treated in the Department of Radiotherapy of the Lahey Clinic Foundation at the High Voltage Research Laboratory of Massachusetts Institute of Technology. Only 2 patients were free of clinical disease in the lower extremities at the time of initial presentation, and 40 patients (69%) had cutaneous lesions involving areas extending above the knees. Eight patients (13%) also presented with mucous membrane involvement in addition to skin disease.

Synchronous Field Shaping and Protection in 2-Million-Volt Rotational Therapy

This presentation is concerned primarily with certain irradiation technics evolved over the past eleven years of clinical radiotherapeutic experience with the 2-million-volt Van de Graaff electrostatic x-ray generator. Field shaping may be considered to have two objectives: that of conforming the shape of the beam of radiation to the known tumor volume and its possible extension and that of protecting adjacent normal areas by exclusion from the beam. In the absence of motion between patient and beam, the field may be given any desired shape depending upon the clinical problem and the philosophy of the radiotherapist. Accessory protective devices in such stationary-field therapy are usually modifications in the outline or dose distribution of the original field. Applied to 360° rotation of the patient, a fixed field is usually considered as necessarily symmetrical about the axis of rotation. The use of an accessory protective device in this situation requires in general that it also be shaped and rotate. T...

The Mechanism and Incidence of Cardiovascular Changes in Paget's Disease (Osteitis Deformans) A Critical Review of the Literature with Case Studies

Although abundant evidence of concomitant cardiovascular disease is scattered throughout the literature on osteitis deformans, appreciation of the etiologic relationship between the two diseases has been lacking. This paper shows that cardiovascular disease accompanying extensive osteitis deformans may result from: (1) excessive demand on the heart from increased vascularity of affected bones; (2) the influence of concomitant arteriosclerosis apparently exceeding the normal for the age concerned; (3) characteristic thoracic spine deformities which compromise cardiorespiratory function, and (4) hypertension. Fifty-four cases are presented. The incidence of cardiovascular disease exceeds that in the general population of the same age and corresponds with the extent of skeletal involvement.

The Results of X-Ray Treatment in Undifferentiated Carcinoma of the Thyroid

This is a presentation of 44 cases of undifferentiated carcinoma of the thyroid treated by 2-Mev radiation. Because of extensive invasion of the neck and mediastinum, surgical cure was not possible, since resections, if attempted, were incomplete. The pathologic findings in the entire group have been reviewed. Our interest in these patients has continued because of our present ability to treat them more vigorously with x-rays than was possible at the time of the last report from this clinic by Hare and Salzman (1) in 1950. In that report the tumors were divided into small-cell and giant-cell carcinomas and the five-year survival rate was 20 per cent. Since 1949 we have treated the majority of these patients with 2-Mev radiation and when possible have tried to give a minimum tissue dose of 4,800 r. In the earlier report the dosages were all in terms of air dose, ranging from 4,800 to 6,000 r (in air). For various reasons many patients in the present series did not receive 4,800 r, some because of their poo...

Field Shaping and Selective Protection in Megavolt Radiation Therapy

The availability of intense sources of megavolt radiation makes possible the treatment of regional as well as localized disease with more adequate doses. These new capabilities are often best exploited by the use of large treatment fields, carefully shaped to include known tumor and local extensions and to exclude uninvolved regions. This procedure results in a more uniform dose distribution and reduces the problems of overlap inherent in the multiple field approach. Field shaping, or field outline control, is accomplished by interposing sufficient thickness of absorbing material into the beam cross section. In addition, the beam may be intensity-modulated by filters to adjust for variations in the anatomical thickness. In our megavolt x-ray equipment a light-beam localizer is used to facilitate the placing of such absorbers and filters. Double-exposure radiographs are taken to confirm and record the field location and the position of these absorbers. Fields of typical shape used in both rotational and op...

Clinical Experiences With Fibrinolysin Therapy

* From the Department of Internal Medicine, The Lahey Clinic, Boston, Mass. † From the Department of Radiology, The Lahey Clinic, Boston, Mass. ‡ The fibrinolysin used in this study was supplied as Actase Fibrinolysin (Human) by the Ortho Pharmaceutical Corporation, Raritan, New Jersey. § Supplied through the courtesy of the Geigy Pharmaceutical Company, New York, New York. This report deals with two groups of patients treated with fibrinolvsin :

Clinical Safety in Low-Megavolt Electron Therapy

(1) eight patients with thrombophlebitis of the arm after radical mastectomy, with venographic observation before and after treatment and (2) four patients with miscellaneous conditions.

Radiotherapy for kaposi's sarcoma

Low-megavolt electrons produced by accelerators offer clinical advantages over low-energy x rays in that they can be used to treat large-area superficial tumors and they yield more favorable dose distributions in depth. In electron therapy it is also important that special precautions be taken to eliminate the chance of an overdose, since the electron dose rates can be extraordinarily high. The accompanying x-ray background, which results in whole-body irradiation, should be kept below an average dose of 20 rads for a treatment series to avoid the production of irreversible blood changes. Electron therapy planning must take into account the gram rad dose due to both electrons and x rays (1). These considerations tend to limit the maximum electron energy used for total skin surface area treatment. In the low-megavolt energy range, the x-ray production efficiency increases in the forward direction approximately as the cube of the electron energy and directly with the atomic number of the material. The accom...

Evaluation for genetic damage in offspring of women with high-level gonadal irradiation.

Between 1954 and 1976, 60 patients with Kaposis sarcoma were treated in the Department of Radiotherapy of the Lahey Clinic Foundation at the High Voltage Research Laboratory of Massachusetts Institute of Technology. Only 2 patients were free of clinical disease in the lower extremities at the time of initial presentation, and 40 patients (69%) had cutaneous lesions involving areas extending above the knees. Eight patients (13%) also presented with mucous membrane involvement in addition to skin disease. Twenty-one patients were treated only with megavoltage electrons during the initial course of radiotherapy, and 12 patients were treated with supervoltage photons alone. The remaining 27 patients were treated with a combination of electrons and photons; in 17 patients, the same tumor sites were irradiated with both modalities. Eleven patients received whole-body surface electron irradiation. The choice of treatment modalities was based on the extent and distribution of cutaneous disease and depth of the lesions. The overall response rate was 93% after a single fractionated course of radiotherapy. Twenty-five patients achieved complete regression and 18 were in remission for 2-13 years. Response rates were also analyzed with respect to the three subgroups in terms of treatment modalities. A single dose of 800 to 1200 rads or its equivalent was required to control local cutaneous lesions. Widespread visceral metastasis was the most common cause of failure and death; the incidence of second malignancies was increased. Trial of systemic chemotherapy and immunotherapy would seem to be a reasonable therapeutic adjunct.

THE VALUE OF 2 MV. ROENTGEN-RAY THERAPY IN DIFFERENTIATED THYROID CARCINOMA

ALMOST all estimates of the existence, nature and magnitude of radiation-induced damage in man have been inferred from animal experimentation. The few reports on the possible mutagenic effects of r...