RESUMO
PURPOSE: We report our single-institution stereotactic body radiation therapy (SBRT) experience on stage I renal cancer with prospectively collected toxicity and efficacy data. METHODS AND MATERIALS: A total of 21 patients with solitary renal tumors, including 14 surgical candidates who refused surgery (66%), were treated with SBRT. Histologic confirmation was obtained on all patients before treatment; 2 had transitional cell carcinoma and 19 had renal cell carcinoma. The median age was 71 years (range, 58-88). Nearly all patients received 48 Gy in 3 fractions. RESULTS: The median follow-up was 78 months (range, 5-107). At 5 years post treatment, the local tumor control rate was 100%. Tumor size decreased by a median value of 5.3% at 1 year post treatment, 15.6% at 2 years post treatment, and 15.4% at 5 years post treatment. Glomerular filtration rate had decreased by a median value of 1.5% at 1 year post treatment, 7.0% at 2 years post treatment, and 14.2% at 5 years post treatment. Three patients experienced grade 1 toxicity; no other treatment-related adverse effects were reported. CONCLUSIONS: SBRT is a promising noninvasive treatment in the management of primary renal cell carcinoma, with evolving clinical evidence demonstrating encouraging results with respect to local control and toxicity.
RESUMO
PURPOSE: We conducted a prospective study to evaluate needle displacements between prostate high-dose-rate (HDR) brachytherapy fractions and offer technical recommendations to help prevent displacements from the outset. METHODS AND MATERIALS: Planning computed tomography and verification computed tomography scans were obtained at 1-mm slice thickness and prospectively assessed for interfraction needle movement for each fraction of a 2-fraction HDR prostate boost. For both the planning and verification CTs, distances from each needle tip to the centroid of 3 implanted prostate gold seeds were measured. We determined the mean and range of the displacement distances. RESULTS: Thirty-three consecutive patients (66 fractions, 540 needle-pair positions for a total of 1080 needles) were evaluated for changes in the length between the needle tip and centroid displacement. Overall, only 0.2% of the needles had any change greater than 3.5 mm between the needle tip and centroid. The mean amount of displacement was 0.97 mm, with a standard deviation of 0.76 mm. Among the patients, no fraction had more than 1 needle with a variation greater than 3.0 mm. CONCLUSIONS: Needle displacements in HDR prostate brachytherapy have been reported by numerous institutions using various techniques. We report the first study to demonstrate needle displacement of less than 1 mm on average, and we describe our process of care surrounding the implantation.
