医学
前列腺癌
随机对照试验
直肠
磁共振成像
放射治疗
前列腺
基准标记
不利影响
影像引导放射治疗
前瞻性队列研究
放射科
外科
核医学
内科学
癌症
作者
Neil Mariados,John Sylvester,Dhiren Shah,Lawrence I. Karsh,Richard Hudes,David Beyer,Steven Kurtzman,Jeffrey A. Bogart,R.A. Hsi,Michael Kos,Rodney J. Ellis,Mark D. Logsdon,S.H. Zimberg,Kevin Forsythe,Hong Zhang,Edward M. Soffen,Patrick Francke,C.A. Mantz,Peter J. Rossi,Theodore L. DeWeese,Daniel A. Hamstra,Walter Bosch,Jeff M. Michalski
标识
DOI:10.1016/j.ijrobp.2015.04.030
摘要
Perirectal spacing, whereby biomaterials are placed between the prostate and rectum, shows promise in reducing rectal dose during prostate cancer radiation therapy. A prospective multicenter randomized controlled pivotal trial was performed to assess outcomes following absorbable spacer (SpaceOAR system) implantation.Overall, 222 patients with clinical stage T1 or T2 prostate cancer underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans for treatment planning, followed with fiducial marker placement, and were randomized to receive spacer injection or no injection (control). Patients received postprocedure CT and MRI planning scans and underwent image guided intensity modulated radiation therapy (79.2 Gy in 1.8-Gy fractions). Spacer safety and impact on rectal irradiation, toxicity, and quality of life were assessed throughout 15 months.Spacer application was rated as "easy" or "very easy" 98.7% of the time, with a 99% hydrogel placement success rate. Perirectal spaces were 12.6 ± 3.9 mm and 1.6 ± 2.0 mm in the spacer and control groups, respectively. There were no device-related adverse events, rectal perforations, serious bleeding, or infections within either group. Pre-to postspacer plans had a significant reduction in mean rectal V70 (12.4% to 3.3%, P<.0001). Overall acute rectal adverse event rates were similar between groups, with fewer spacer patients experiencing rectal pain (P=.02). A significant reduction in late (3-15 months) rectal toxicity severity in the spacer group was observed (P=.04), with a 2.0% and 7.0% late rectal toxicity incidence in the spacer and control groups, respectively. There was no late rectal toxicity greater than grade 1 in the spacer group. At 15 months 11.6% and 21.4% of spacer and control patients, respectively, experienced 10-point declines in bowel quality of life. MRI scans at 12 months verified spacer absorption.Spacer application was well tolerated. Increased perirectal space reduced rectal irradiation, reduced rectal toxicity severity, and decreased rates of patients experiencing declines in bowel quality of life. The spacer appears to be an effective tool, potentially enabling advanced prostate RT protocols.