Norah duV. Tapley

Bilateral breast cancer in patients with initial stage I and II disease.

Between January 1947 and the end of 1976, of 2076 patients with Stages I and II breast cancer treated at M. D. Anderson Hospital, 126 received treatment for cancer in both breasts. Records of 94 patients who had only one cancer treated at U. T. M. D. Anderson Hospital and in whom staging and treatment details were not available and records of the patients who developed local, regional, or systemic failure prior to the diagnosis of the second breast were excluded. Of 126 patients with bilateral breast cancer, 39 had simultaneous tumors (both cancers diagnosed within six months) and 87 had consecutive tumors. The disease‐free 20‐year survival rate shows no significant difference between patients with unilateral tumors and those with bilateral simultaneous or consecutive tumors. Analysis by radiotherapy modality or surgery alone shows, if anything, a lower incidence of cancer in the second breast in the irradiated patients, indicating that in patients with Stage I or Stage II lesions, the doses of radiation given in the management of the first breast cancer were not conducive to the development of a cancer in the remaining breast.

Results in patients with breast cancer treated by radical mastectomy and postoperative irradiation with no adjuvant chemotherapy.

In 1963 an electron beam became available, making irradiation of the chest wall technically easy. In addition to peripheral lymphatic irradiation in patients with positive axillary nodes and/or the tumor in the inner quadrants or centrally located, patients with tumor larger than 5 cm or with grave signs and/or a significant incidence of positive axillary nodes received chest wall irradiation. None of the patients has received elective chemotherapy. Disease‐free survival rates at ten years are 54% for the overall group, 79% for the patients with negative nodes, 44% for patients with positive nodes, 61% for patients with 1–3 positive nodes, and 33% for patients with four or more positive nodes. The incidence of peripheral lymphatic failures is low as well as the incidence of failures on the chest wall in the patients having had chest wall irradiation. With the availability of electron beam and adjustments in doses, complications are nonexistent. The incidence of treatment failures, local‐regional, or distant, that have appeared by ten years are compared with the incidence of failures that were experienced by the placebo patients in the clinical trial of the NSABP of thio‐TEPA versus placebo. The clearly lesser incidence of treatment failures in the U.T.M.D. Anderson Hospital patients either suggests that postoperative irradiation may have survival benefits or that the data of the NSABP series are not representative of all series.

High-Energy Electron Dose Perturbations in Regions of Tissue Heterogeneity

High-energy electron dose perturbations produced by variations in density and structure of the irradiated material have been demonstrated in phantoms by a number of investigators (5, 6, 10, 14–17, 19, 20), sometimes employing anatomical specimens such as bone (10, 25, 27). In one study (11), dose distortions produced by bone and air spaces in electron treatment of the nasopharynx were mapped in sectioned cadaver heads. We have investigated these dose perturbations in living tissues, using lithium fluoride thermoluminescent dosimeters. Several excellent reviews of the properties of lithium fluoride as a radiation dosimeter (7, 13) and of its use in measuring doses in irradiated patients (18, 21) and experimental animals (2) are available. In our experience, accuracies of ± 3 per cent are obtainable for lithium fluoride dosimeters in vivo, and ± 1 per cent for carefully controlled laboratory exposures. Over 500 in vivo dose determinations in 75 dogs and 25 patients comprise the data from this two-year inves...

Applications of the electron beam in the treatment of cancer of the skin and lips.

The 6 to 18 MeV electron beam was used for treatment of 156 patients with squamous and basal-cell carcinomas of the skin and lips. With use of this simple reproducible technique, underlying normal structures are minimally damaged and adjacent structures are easily protected with thin sheets of lead. Primary control with electron beam treatment was 86% for all sites in patients followed for 2 to 8.5 years. With surgical treatment of 15 patients who had persistence or recurrence of disease, 10 patients were salvaged with a final control rate of 95%. The cosmetic results were excellent.

Skin Reactions and Tissue Heterogeneity in Electron Beam Therapy. Part I: Clinical Experience1

The purpose of this paper is twofold: (a) to provide skin tolerance tables for electron beam therapy and (b) to evaluate the clinical significance of alterations in the electron beam depth dose produced by nonhomogeneous tissues. Although the electron beam was first used to treat patients almost fifteen years ago, a review of the literature has not provided tables which correlate the degree of skin reaction with dose, time, area, and anatomical location such as Paterson recorded for kilovoltage radiation in 1948 (10). In the published clinical papers, the alteration of dose distribution by the interposition of bone or air spaces in the path of the beam has not been emphasized as an important factor in treatment planning with electrons. Skin Reactions One of the first studies of the response of human skin to electrons was that of Haas et al. (5, 6) in a comparison of 17 Mev electrons versus 200 kv x rays. They established that a higher exposure dose of electrons was required to produce the same degree of e...

The Electron Beam in Tumor Therapy

Experience with 1,300 patients indicates that therapy with the electron beam is effective for selected malignancies, particularly tumors involving or located near the skin surface. Because the electron beam rapidly loses energy as it travels through tissue, deeper structures are spared the effects of more penetrating forms of irradiation. When indicated, the electron beam can be combined with other radiation sources.

Limited Volume Radiation Therapy with the Electron Beam

The tolerance of tissues to radiation is dependent upon the volume of tissue irradiated, decreasing rapidly with increasing volume. Irreversible injury to the tissues, which may result in bone and softtissue necrosis, laryngeal edema, dryness of the mucous membrane, and connective-tissue fibrosis, is unavoidable in applications of megavoltage x-or gamma-radiation through parallel opposed fields. Even though single lateral or wedge fields are used, the radiation dose to the normal tissues adjacent to the tumor is often excessive. The electron beam of 6 to 20 Mev energy has a rapid build-up with the high dose level being reached within the superficial millimeters of tissue and being maintained from 1.5 to 5 cm. in depth. The degree of skin reaction is somewhat more pronounced than that seen with cesium 137 but is not of the samemagnitude as observed with 250-kv radiation. The depth in tissue where the rapid decrease in absorbeddose occurs is dependent upon the energy level of the electron beam. With a peak ...