The Difficulties of a Randomized Study in Superior Vena Caval Obstruction

IntroductionSuperior vena caval obstruction (SVCO) is a not uncommon complication of malignant disease. Treatment may consist of radiation (RT) to the mediastinum, systemic therapy for chemosensitive tumors, and supportive measures such as oxygen and steroids. Advances in interventional radiology have allowed the introduction of expandable stents into the superior vena cava (SVC), with the theoretical advantage of providing symptom relief within hours, rather than the days and weeks over which RT exerts its effect. Although small case series have supported the use of stents in SVCO, there are no randomized data.MethodsWe set up a randomized study at Princess Margaret Hospital, Toronto. Patients were randomized to receive palliative RT to the mediastinum or immediate stenting of the SVC and then mediastinal RT within a week. The aim of the study was to compare symptom response between the two treatment arms. A second study, a prospective longitudinal study, was also set up to obtain information on symptom response and outcome regardless of the treatment given.ResultsIn a 12-month period, we were unable to accrue any patients in the randomized study; of the 19 patients approached, 13 have agreed to participate in the longitudinal study.ConclusionsIn this report, we present the problems that we have encountered with these studies.