Residual mediastinal mass after treatment of Hodgkin's disease: a decision analysis

A residual mediastinal mass after completion of initial treatment for Hodgkin's disease is a frequent clinical problem. Investigators have suggested three possible approaches to this important problem: 1) observation, 2) additional diagnostic tests with subsequent action based upon test results, or 3) immediate treatment for high-risk patients. The method of decision analysis was applied to determine the optimal management for residual mediastinal abnormalities following treatment of Hodgkin's disease with combined modalities of MOPP chemotherapy and radiation therapy. The three parameters of the importance for making the best decision were: 1) the probability that the mass is truly active disease, 2) the salvage success rate using MOPP or ABVD treatment and 3) the specificity of the gallium scan. The analysis favored the gallium imaging strategy as an initial management choice when the probability was greater than 3% that the residual mass represented active disease and the specificity of gallium imaging was greater than 56%. This strategy proved to be the most cost effective, as well. Additional chemotherapy was favored only when there was a greater than 99% probability that the mass represented active disease. A nomogram has been constructed combining all three parameters of importance for graphically determining the best decision.