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

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.

Stereotactic body radiotherapy for localized prostate cancer – 5-year efficacy results

“…SBRT for localized PCa is feasible also with modern, image-guided linear accelerators [ 29 , 30 ]. In previously published data, the acute GU and rectal toxicity have been tolerable with grade 3 adverse events seldom reported and the biochemical control rates have been high [ 29 ].…”

“…SBRT for localized PCa is feasible also with modern, image-guided linear accelerators [ 29 , 30 ]. In previously published data, the acute GU and rectal toxicity have been tolerable with grade 3 adverse events seldom reported and the biochemical control rates have been high [ 29 ]. The non-randomized patient cohort published by Nicosia et al evaluated 149 low and favorable-profile intermediate-risk PCa patients treated to the total doses of 35 and 37.5 Gy delivered in five consecutive fractions of 7 and 7.5 Gy, respectively [ 31 ].…”

Constraint Analysis and Bladder Wall Low-Dose-Constraint Reduction in Five-Fraction Urethra-Sparing Prostate SBRT

“…Lower values of this ratio imply a higher sensitivity of the associated tissue to changes in fractionation. Evidence suggests that prostate alpha/beta ratio is nearly 1.5 Gy [11] [12] [13] [14] or even lower, which is much lower than those of neighboring tissues such as the Rectum Wall, urethra or Bladder Wall (3 -5 Gy) [15]. These differences suggest the possibility of having a greater Biological Equivalent Dose (BED) to the tumor while improving the therapeutic ratio [16] [17], supporting extreme hypofractionated SBRT as the ideal approach [18].…”

The Development of Robotic Technology in Cardiac and Vascular Interventions

“…Robotic technology has been used in medicine for several decades, primarily in the fields of surgery1–3 and radiation therapy 4,5. The use of robotics in cardiovascular medicine began in the early 2000s, and since its introduction robotics has made a tremendous impact in the field.…”

“…Robotic technology has been used in medicine for several decades, primarily in the fields of surgery 1 – 3 and radiation therapy. 4 , 5 The use of robotics in cardiovascular medicine began in the early 2000s, and since its introduction robotics has made a tremendous impact in the field. Today robotic technology is commonly used to assist in a number of surgical procedures including minimally invasive atrial septal defect closure, mitral valve repair, coronary artery bypass graft surgery, and, more recently, in electrophysiology procedures involving radiofrequency arrhythmia ablation.…”