Malignant Bone Lesions Research Articles

Strontium-85 scanning of suspected bone disease.

Strontium-85 scanning of suspected bone lesions in 81 patients has added to the criteria for the diagnosis of malignant and other lesions of bone. Of 46 patients with a previous history of malignant disease and skeletal symptoms negative radiological findings were recorded in 19, but nine of these had positive scans, eight of which when followed up over periods of up to four years proved to be metastatic. A similar prevalence of positive scans occurred in patients without a previous history of malignancy. Because of the anatomical localization of lesions made possible by this technique a tissue diagnosis was made in six patients, while fields of radiotherapy were altered in another seven. This technique can improve the management of patients with suspected bone disease.

Calcium-47 and strontium-85 tracer studies as a guide to isotope therapy of bone metastases.

Palliative therapy for patients with metastases from mammary cancer constitutes an important problem. It has been well demonstrated that endocrine ablative therapy yields effective systemic control and that irradiation affords useful local control of the disease in a significant number of patients. Appropriate integration of these two modalities can frequently produce worthwhile palliation. Friedell and Storaasli (1) were the first to report the use of P32 intravenously for the treatment of widespread osseous mammary metastases. In a more recent evaluation, Storaasli et al. (2) reported objective improvement in 26 per cent of a selected group of patients with predominantly osseous metastases receiving intravenous injections of P32. These workers have also combined adrenalectomy and intravenous P32 in a small, highly selected series of cases. Fifteen of 22 patients obtained objective improvement averaging 15+ months in duration. Although these results suggest that there is an additive effect of these two therapeutic agents, this could not be conclusively demonstrated. The rationale for isotope therapy is based on selective uptake of the isotope in the area of the lesion. The uptake of P32 in human mammary cancer does not appear to be very selective. Kenney et al. (3) found a differential uptake in primary breast cancers of 2 to 7 times that of normal breast tissue, and lymph nodes which contained metastatic foci of breast cancer took up to 1.3 to 2.8 times as much of the isotope as uninvolved lymph nodes. Therapeutic trials with intravenous P32 (1, 2, 4) have produced improvement only in metastatic osseous lesions, whereas soft-tissue lesions are unaffected. On the other hand, a more selective uptake of P32 has been demonstrated in osseous mammary metastases both by direct measurement (5) and by radioautographs (1, 4). These observations indicate that selective uptake of P32 in bone surrounding the tumor affords the major potential for the therapeutic use of isotopes. The use of P32 for the treatment of bone metastases has so far been purely empirical, since no convenient method exists for the measurement of differential uptake of P32 in individual patients. Since only one-fourth of a selected group obtained benefit from this therapy, it would seem important to be able to select those who are likely to be helped, as well as to avoid the hazards of this procedure in those who will probably not be benefited. The recent availability of a radioactive isotope of calcium (Ca47) has provided an ideal tracer for calcium kinetic studies and for local uptake measurements over the skeleton by external counting. Preliminary results of Ca47 tracer studies in patients with malignant lesions of bone have shown that both progressive and healing bone lesions may be associated with an increased accretion rate of calcium in the skeleton as a whole due to an increased local uptake in the lesion areas (6).

The latent period, incidence, and growth of Sr90-induced osteosarcomas in CF1 and CBA mice.

Investigations of the carcinogenic response of laboratory animals to ionizing radiation, either externally or internally applied, are usually focused upon the neoplasms present at death. Consequently the morbidity data are very closely bound to the mortality data, an association that is often overlooked. However, an appreciation of the fact that the true incidence of a disease may be quite different from its apparent incidence at death does not automatically solve the problem of separating morbidity from mortality, because in most instances the recognition of neoplastic disease must wait until the mass can be palpated, or until necropsy. A notable exception is the malignant bone lesion, which can be detected roentgeno-graphically in the living animal long before it can be palpated. The objectives of the present investigation, employing periodic x-ray examination of the skeletons of mice that had received radiostrontium, were: (a) to study the development of osteosarcoma as a disease apart from mortality, (b) to follow the growth of individual tumors from their first roentgenographic identification to the death of the host, and (c) to compare the radiocarcinogenic responses of two distinct strains of mice. Each of these aspects of the investigation is pertinent to the problem of latent period, which is one of the very intriguing but poorly understood characteristics of tumor induction. Materials and Methods Sr90, in equilibrium with Y90, was injected intravenously into 29 CF1 and 24 CBA female mice approximately seventy days old. The former received an average of 0.9 μc/gm. body weight (range, 0.81 to 1.03 μc/gm.) and the latter an average of l.lμc/gm. (range, 0.96 to 1.23 μc/gm.). This amount of Sr90 is known to produce a high incidence of osteosarcoma (1). Roentgenograms were taken one month after injection, at two- to four-week intervals during the next two months, and weekly thereafter. The final picture was obtained at autopsy. Exposure required three-quarters of a second at 30 ma and 32 kv 19 inches from the tube. The radiation received by the mice from this procedure was insignificant compared with that derived from the Sr90-Y90. By retrospective examination of the roentgenograms, the sarcomas present at death could be traced back to their first appearance. It was sometimes difficult to determine the earliest film of a specific lesion with definite neoplastic characteristics, and some lesions persisted in an apparent nonmalignant state for many weeks. If the integrity of the cortex was interrupted, malignancy was diagnosed. In a few instances the cortex was intact, but the general appearance of the lesion favored a diagnosis of malignancy.