title: Radiation exposure from CT-guided ablation of renal masses: effects on life expectancy.
abstract: 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.
authors.affiliation: 1 Institute for Technology Assessment, Massachusetts General Hospital, 101 Merrimac St, 10th Fl, Boston, MA 02114.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Eisenberg
authors.forename: Debra A
authors.initials: DA
authors.lastname: Gervais
authors.forename: Sarabjeet
authors.initials: S
authors.lastname: Singh
authors.forename: Mannudeep K
authors.initials: MK
authors.lastname: Kalra
authors.forename: Sharjeel H
authors.initials: SH
authors.lastname: Sabir
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Paul
authors.forename: Pari V
authors.initials: PV
authors.lastname: Pandharipande
mesh_terms: D000368:Aged; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging / Q000401:mortality* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality* / Q000601:surgery*; D008017:Life Expectancy; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology* / Q000209:etiology*; D011829:Radiation Dosage; D018570:Risk Assessment; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed / Q000009:adverse effects*
keywords: CT; decision analysis; radiation risk; radiofrequency ablation; renal cancer