Research and Reports in Urology (Aug 2016)

A comparison of robotic arm versus gantry linear accelerator stereotactic body radiation therapy for prostate cancer

  • Avkshtol V,
  • Dong Y,
  • Hayes SB,
  • Hallman MA,
  • Price RA,
  • Sobczak ML,
  • Horwitz EM,
  • Zaorsky NG

Journal volume & issue
Vol. Volume 8
pp. 145 – 158

Abstract

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Vladimir Avkshtol, Yanqun Dong, Shelly B Hayes, Mark A Hallman, Robert A Price, Mark L Sobczak, Eric M Horwitz,* Nicholas G Zaorsky* Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA, USA *These authors contributed equally to this work Abstract: Prostate cancer is the most prevalent cancer diagnosed in men in the United States besides skin cancer. Stereotactic body radiation therapy (SBRT; 6–15 Gy per fraction, up to 45 minutes per fraction, delivered in five fractions or less, over the course of approximately 2 weeks) is emerging as a popular treatment option for prostate cancer. The American Society for Radiation Oncology now recognizes SBRT for select low- and intermediate-risk prostate cancer patients. SBRT grew from the notion that high doses of radiation typical of brachytherapy could be delivered noninvasively using modern external-beam radiation therapy planning and delivery methods. SBRT is most commonly delivered using either a traditional gantry-mounted linear accelerator or a robotic arm-mounted linear accelerator. In this systematic review article, we compare and contrast the current clinical evidence supporting a gantry vs robotic arm SBRT for prostate cancer. The data for SBRT show encouraging and comparable results in terms of freedom from biochemical failure (>90% for low and intermediate risk at 5–7 years) and acute and late toxicity (<6% grade 3–4 late toxicities). Other outcomes (eg, overall and cancer-specific mortality) cannot be compared, given the indolent course of low-risk prostate cancer. At this time, neither SBRT device is recommended over the other for all patients; however, gantry-based SBRT machines have the abilities of treating larger volumes with conventional fractionation, shorter treatment time per fraction (~15 minutes for gantry vs ~45 minutes for robotic arm), and the ability to achieve better plans among obese patients (since they are able to use energies >6 MV). Finally, SBRT (particularly on a gantry) may also be more cost-effective than conventionally fractionated external-beam radiation therapy. Randomized controlled trials of SBRT using both technologies are underway. Keywords: prostate cancer, stereotactic body radiation therapy, technology, quality of life

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