Perfluoroctylbromide contrast enhancement of malignant neoplasms: preliminary observations

Fluorocarbons have been used for years as propellants in aerosol sprays. Because of their ability to transport oxygen, perfluorocarbon compounds have been more recently used in artificial fluid respiration. Monobrominated perfluorocarbon compounds are radiopaque and have low enough vapor pressures to be tolerated in biologic systems. Microemulsions of these compounds have been detected in mouse and rat neoplasms and appear to be located within macrophages. In this study of the potential usefulness of these compounds for radiographic contrast enhancement, rabbits with V2 carcinoma thigh implants received either a high-dose (10--12 ml/kg) or a low-dose (2 ml/kg) emulsion of perfluoroctylbromide intravenously. Dense contrast enhancement of some of the V2 carcinomas was demonstrated by both computed tomography and conventional radiography. Four of the five rabbits in the high-dose group died within 9 days but all six rabbits in the low-dose group survived beyond 9 days. Death in the high-dose group was associated with pulmonary consolidation and anesthesia although some animals had extensive V2 metastases. These compounds have some interesting potential applications in imaging, pending further study of their toxicity.