Postimplant dosimetry for 125I prostate implants: definitions and factors affecting outcome

摘要: Abstract Objective: An analysis of CT-based dosimetry was performed to assess the efficacy real time method prostate implantation, explore relationship various dose descriptions and determine implant factors affecting outcome. Methods Materials: Between 7/95 8/99, 297 patients underwent 125 I implants for T1–T2 cancer had (TG43 formalism). Dosimetry 1 month postimplant. Using a dose–volume histogram, doses delivered 100%, 95%, 90%, 80% (D100, D95, D90, D80, respectively) as well percentages gland receiving 240 Gy, 160 140 Gy (V240, V160, V140, were reported. Correlations between parameters D90 generated. The effect number seeds implanted, seeds/volume, volume, experience assessed by (8/01/99—date implant), ultrasound probe (mechanical sector vs. dual phased electronic), ratio CT volume/ultrasound volume (CT/US vol) analyzed. Results: median D100, D80 values 10,200 cGy, 15,655 17,578 19,873 respectively. V240, V140 56%, 94%, 98%, found close with r 0.928, 0.973, 0.911, 0.816, 0.733, D100 correlated poorly ( = 0.099). stepwise regression analysis, CT/US vol ratio, seed only significant having greatest effect. dual-phased electronic associated fewer less than (2%) compared mechanical (14%) p 0.02). Conclusion: results reveal real-time technique be an effective implantation. Factors more precise such decreased postimplant edema, new technology, increased will lead higher values.