Figure 2.

Cost-effectiveness of external beam radiation therapy (EBRT) and newer modalities based on patient age and comorbidity. Solid bars represent the ranges of incremental cost-effectiveness ratio for EBRT, and dotted bars represent those for intensity modulated radiation therapy (IMRT), according to patient age and comorbidity. Conditions used to create comorbidity categories included congestive heart failure, cardiac arrhythmias, valvular disease, pulmonary circulation disorders, peripheral vascular disorders, paralysis, other neurological disorders, chronic pulmonary disease, diabetes, renal failure, liver disease, AIDS/human immunodeficiency virus, lymphoma, metastatic cancer, solid tumor without metastasis, rheumatoid arthritis/collagen, coagulopathy, weight loss, fluid and electrolyte disorders, deficiency anemia, alcohol abuse, drug abuse, psychoses, depression. We calculated the actual survival for each age group and comorbidity combination. Each combination was categorized into four groups based on 10-year survival (0%–25%, 25%–50%, 50%–75%, 75%–100%). A series of simulations integrating the corresponding mortality rate and age estimated the cost-effectiveness of EBRT (or IMRT) across these four categories. We assumed IMRT did not reduce the risk of local recurrence (compared with EBRT) but increased utility by 25% for the health state of no recurrence. QALY = quality-adjusted life-year.