Microsimulation model predicts survival benefit of radiofrequency ablation and stereotactic body radiotherapy versus radiotherapy for treating inoperable stage I non-small cell lung cancer.

OBJECTIVE: A subset of patients with stage IA and IB non-small cell lung cancer (NSCLC) is ineligible for surgical resection and undergoes radiation therapy. Radiofrequency ablation (RFA) and stereotactic body radiotherapy are newer potentially attractive alternative therapies. MATERIALS AND METHODS: We added RFA and stereotactic body radiotherapy treatment modules to a microsimulation model that simulates lung cancer's natural history, detection, and treatment. Natural history parameters were previously estimated via calibration against tumor registry data and cohort studies; the model was validated with screening study and cohort data. RFA model parameters were calibrated against 2-year survival from the Radiofrequency Ablation of Pulmonary Tumor Response Evaluation (RAPTURE) study, and stereotactic body radiotherapy model parameters were calibrated against 3-year survival from a phase 2 prospective trial. We simulated lifetime histories of identical patients with early-stage NSCLC who were ineligible for resection, who were treated with radiation therapy, RFA, or stereotactic body radiotherapy under a range of scenarios. From 5,000,000 simulated individuals, we selected a cohort of patients with stage I medically inoperable cancer for analysis (n = 2056 per treatment scenario). Main outcomes were life expectancy gains. RESULTS: RFA or stereotactic body radiotherapy treatment in patients with peripheral stage IA or IB NSCLC who were nonoperative candidates resulted in life expectancy gains of 1.71 and 1.46 life-years, respectively, compared with universal radiation therapy. A strategy where patients with central tumors underwent stereotactic body radiotherapy and those with peripheral tumors underwent RFA resulted in a gain of 2.02 life-years compared with universal radiation therapy. Findings were robust with respect to changes in model parameters. CONCLUSION: Microsimulation modeling results suggest that RFA and stereotactic body radiotherapy could provide life expectancy gains to patients with stage IA or IB NSCLC who are ineligible for resection.

Enhancing patient safety: standardization of CT contrast media practices.

Large health care systems with varied hospital cultures, environments, and practices are continually challenged to provide safer and higher quality patient care. The authors describe their experience implementing uniform procedures for computed tomographic contrast media administration and the impact that standardization of these practices had on patient safety at a large integrated health care system.

The effect of prior colonic imaging on endoscopic productivity: potential impact of computed tomographic colonography.

BACKGROUND & AIMS: If computed tomographic colonography (CTC) is used for primary colorectal cancer (CRC) screening with a small polyp size threshold to define a CTC study as positive, a substantial portion of all colonoscopies performed annually will be to follow up positive CTC examinations. Moreover, the majority of positive CTC examinations would be false positives (FP). This case-control study was undertaken to test the hypothesis that colonoscopy examinations resulting from FP CTC studies would take longer to complete than negative screening colonoscopies. METHODS: Endoscopic records of a large, urban hospital were reviewed to identify all patients who had either a positive barium enema (BE) study or flexible sigmoidoscopy (FS) and a negative follow-up colonoscopy examination (these patients were used as surrogates for CTC FP cases). For each of the 28 FP patients or cases identified, 2 screening colonoscopies performed by the same endoscopist within the same time period were identified and used as matched controls. A two-way analysis of variance test was performed to assess for differences in time to complete colonoscopies between these 2 groups, controlling for the individual endoscopist. RESULTS: FP colonoscopies took an average of 24.0 minutes to complete, whereas negative screening colonoscopies took 14.9 minutes; FP colonoscopies required 61% more active time to complete. This highly statistically significant difference (P < .0001) persisted with subset analyses that only included BE or FS cases and when fellow or surgeon cases were excluded. CONCLUSIONS: FP colonoscopies take longer to perform than negative screening colonoscopies. If CTC is implemented as the primary modality for CRC screening, these FP examinations could comprise a substantial percentage of the colonoscopies performed, potentially leading to a significant decrease in endoscopic productivity.

Metastatic colorectal carcinoma: cost-effectiveness of percutaneous radiofrequency ablation versus that of hepatic resection.

PURPOSE: To evaluate the relative cost-effectiveness of radiofrequency (RF) ablation and hepatic resection in patients with metachronous liver metastases from colorectal carcinoma (CRC) and compare the outcomes, cost, and cost-effectiveness of a variety of treatment and follow-up strategies. MATERIALS AND METHODS: A state-transition decision model for evaluating the (societal) cost-effectiveness of RF ablation and hepatic resection in patients with CRC liver metastases was developed. The model tracks the presence, number, size, location, growth, detection, and removal of up to 15 individual metastases in each patient. Survival, quality of life, and cost are predicted on the basis of disease extent. Imaging, ablation, and resection affect outcomes through detection and elimination of individual metastases. Several patient care strategies were developed and compared on the basis of cost, effectiveness, and incremental cost-effectiveness (expressed as dollars per quality-adjusted life-year [QALY]). Extensive sensitivity analysis was performed to evaluate the impact of alternative scenarios and assumptions on results. RESULTS: A strategy permitting ablation of up to five metastases with computed tomographic (CT) follow-up every 4 months resulted in a gain of 0.65 QALYs relative to a no-treat strategy, at an incremental cost of $2400 per QALY. Compared with this ablation strategy, a strategy permitting resection of up to four metastases, one repeat resection, and CT follow-up every 6 months resulted in an additional gain of 0.76 QALYs at an incremental cost of $24 300 per QALY. Across a range of model assumptions, more aggressive treatment strategies (ie, ablation or resection of more metastases, treatment of recurrent metastases, more frequent follow-up imaging) were superior to less aggressive strategies and had incremental cost-effectiveness ratios of less than $35 000 per QALY. Findings were insensitive to changes in most model parameters; however, results were somewhat sensitive to changes in size thresholds for RF ablation, the number of metastases present, and surgery and treatment costs. CONCLUSION: RF ablation is a cost-effective treatment option for patients with CRC liver metastases. However, in most scenarios, hepatic resection is more effective (in terms of QALYs gained) than RF ablation and has an incremental cost-effectiveness ratio of less than $35 000 per QALY.