THE COST-EFFECTIVENESS OF STEREOTAXIC RADIOSURGERY VERSUS SURGICAL RESECTION IN THE TREATMENT OF SOLITARY METASTATIC BRAIN-TUMORS

SOLITARY METASTATIC BRAIN tumors are the most common intracranial neop lasms encountered by neurosurgeons. Surgical resection of brain metast asis with whole brain radiotherapy (WBR) significantly increases survi val in comparison with WBR alone. Stereotactic radiosurgery (SR) seems to provide results that are similar to those of surgical resection. T o analyze the economic efficiency of these different treatments, we co mpared the results of surgical resection and SR as reported in the med ical literature between 1974 and 1994. We included studies in which: 1 ) at least 75% of patients received WBR; 2) study dates were in the co mputed tomography era (after 1975); 3) operative morbidity, mortality, and median survival were reported; 4) study dates were not included i n a more recent update or review; 5) tumor histologies were reported; and 6) the cobalt-60 gamma unit was used for SR. Three surgical resect ion studies and one SR study met all entry requirements. The WBR basel ine was developed from two prospective, randomized trials and used for incremental cost effectiveness analysis. We developed a model of typi cal resource usage for uncomplicated procedures, reported complication s, and subsequent craniotomies (for recurrent tumor or radiation necro sis) for both treatment options. Costs were estimated from the societa l viewpoint using the 1999 Medicare Provider Analysis and Review datab ase with average cost:charge ratios for surgery and WBR. A survey of c apital and operating costs from five sites was used for radiosurgery. Our analysis revealed that radiosurgery had a lower uncomplicated proc edure cost ($20,209 versus $27,587), a lower average complication cost per case ($2,534 versus $2,874), and a lower total cost per procedure ($22,743 versus $30,461), was more cost effective ($24,811 versus $32 ,149 per life year), and had a better incremental cost effectiveness ( $40,648 versus $52,384 per life year) than surgical resection. A sensi tivity analysis revealed that large changes in key assumptions would b e required to change the analysis outcome. Equalization of the increme ntal cost effectiveness of the two treatments would require one of the following: 1) a 38.7% reduction in SR annual case volume, 2) a 34.7% increase in SR procedure cost, 3) a 18.8% reduction in surgical resect ion procedure cost, 4) a 240.5% increase in SR morbidity cost, 5) a 12 .7% reduction in SR median survival, 6) a 16.8% increase in surgical r esection median survival. Elimination of all surgical resection morbid ity cost would still result in superior incremental cost effectiveness for SR. These results indicate the need for prospective clinical tria ls that examine both the clinical efficacy and the cost effectiveness of surgical resection and SR in the management of solitary metastatic brain tumors.