Radiation exposure from CT-guided ablation of renal masses: effects on life expectancy
Senior Scholars Program; School of Medicine
Pari Pandharipande, MD, MPH/Mass. General Hospital – Institute for Technology Assessment
Medical Subject Headings
Aged; Carcinoma, Renal Cell; Catheter Ablation; Female; Humans; Kidney Neoplasms; *Life Expectancy; Male; Neoplasms, Radiation-Induced; Radiation Dosage; Risk Assessment; *Surgery, Computer-Assisted; Tomography, X-Ray Computed
Neoplasms | Radiology
OBJECTIVE. The purpose of this article is to project the effects of radiation exposure on life expectancy (LE) in patients who opt for CT-guided radiofrequency ablation (RFA) instead of surgery for renal cell carcinoma (RCC).
MATERIALS AND METHODS. We developed a decision-analytic Markov model to compare LE losses attributable to radiation exposure in hypothetical 65-year-old patients who undergo CT-guided RFA versus surgery for small ( < /= 4 cm) RCC. We incorporated mortality risks from RCC, radiation-induced cancers (for procedural and follow-up CT scans), and all other causes; institutional data informed the RFA procedural effective dose. Radiation-induced cancer risks were generated using an organ-specific approach. Effects of varying model parameters and of dose-reduction strategies were evaluated in sensitivity analysis.
RESULTS. Cumulative RFA exposures (up to 305.2 mSv for one session plus surveillance) exceeded those from surgery (up to 87.2 mSv). In 65-year-old men, excess LE loss from radiation-induced cancers, comparing RFA to surgery, was 11.7 days (14.6 days for RFA vs 2.9 days for surgery). Results varied with sex and age; this difference increased to 14.6 days in 65-year-old women and to 21.5 days in 55-year-old men. Dose-reduction strategies that addressed follow-up rather than procedural exposure had a greater impact. In 65-year-old men, this difference decreased to 3.8 days if post-RFA follow-up scans were restricted to a single phase; even elimination of RFA procedural exposure could not achieve equivalent benefits.
CONCLUSION. CT-guided RFA remains a safe alternative to surgery, but with decreasing age, the higher burden of radiation exposure merits explicit consideration. Dose-reduction strategies that target follow-up rather than procedural exposure will have a greater impact.
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Citation: AJR Am J Roentgenol. 2015 Feb;204(2):335-42. doi: 10.2214/AJR.14.13010. Link to article on publisher's site
Eisenberg, Jonathan D.; Gervais, Debra A.; Singh, Sarabjeet; Kalra, Mannudeep K.; Sabir, Sharjeel H.; Paul, Aaron B.; and Pandharipande, Pari V., "Radiation exposure from CT-guided ablation of renal masses: effects on life expectancy" (2015). University of Massachusetts Medical School. Senior Scholars Program. Paper 228.