The syndrome of superior vena caval obstruction, characterized by the rapid onset of facial edema, puffiness of the arms, prominent venous pattern of the chest wall, and increasing dyspnea, is alarming to the patient and challenging to the physician. This constitutes an urgent medical problem and requires the cross-consultation of many disciplines in which philosophies may differ. For this reason, it seemed appropriate to re-evaluate present concepts regarding specific diagnostic tests and current therapeutic approaches with particular attention to the problem of radiation edema. Diagnosis of the acute syndrome is rarely a problem, but the etiology is more difficult to establish. From reviews of the literature2 by Fischer (1904), Hinshaw (1949), MacIntire and Sykes (1949) and Schechter (1954), the incidence of primary thoracic neoplasm as the cause for obstruction seems to have been relatively constant, ranging from 35 to 51.5 per cent. However, there can be little doubt that in recent years carcinoma of the bronchus accounts for at least 80 per cent of the cases, and, with other intrathoracic neoplasms, probably more than 90 per cent of all acute caval obstructions. This is due not only to the rising number of bronchogenic carcinomas in males but also to the control of syphilis and tuberculosis by antibiotic and chemotherapeutic agents. Depending upon whether the figure of 5 or of 15 per cent is used as the incidence of superior vena caval obstruction in bronchogenic carcinoma, it is anticipated that 2,000 to 5,500 new cases may present each year in this country. This, therefore, is a major problem and one which will demand increasing attention. Various aspects of this syndrome will be discussed as follows: 1. Etiology and Surgical Approaches, by J. Gordon Scannell, M.D., Harvard Medical School, Boston, Mass. 2. Phlebography, by Norman Howard, M.A., B.M., F.F.R., D.M.R.T., Royal Marsden Hospital, London, England. 3. The Mandate for Chemotherapeutic Decompression, by William Geller, M.D., Memorial-Sloan-Kettering Cancer Center; Cornell University Medical College, New York, N. Y. 4. Superior Vena Caval Syndrome: Slow Low-Dose versus Rapid High-Dose Schedules, by Philip Rubin, M.D., and others, Strong Memorial Hospital, Rochester, N. Y. 5. The Treatment of Superior Vena Caval Syndrome by High-Dose Grid Technic, by K. S. Holmes, M.B.Ch.B., M.R.C.P.E., F.F.R., Christie Hospital and Holt Radium Institute, Manchester, England.