Reduction of Postradiation Therapy Urinary Toxicity Via Intrafractional Megavoltage-Kilovoltage Prostate Location Monitoring.

Purpose: We hypothesized that an in-house developed system using megavoltage and kilovoltage image guidance (MKIG) to ensure correct prostate positioning during stereotactic body radiation therapy (SBRT) could potentially avoid unwanted doses to nontarget tissues, leading to reduced toxicities.

Methods And Materials: We built a 3-dimensional MKIG platform that accurately tracks prostate implanted fiducials in real time and clinically translated the system to replace a commercial approach, intrafraction motion review (IMR), which only tracks fiducials in the 2-dimensional kilovoltage views. From 2017 to 2019, 150 patients with prostate cancer were treated with SBRT and monitored using MKIG.

Quantifying clinical severity of physics errors in high-dose rate prostate brachytherapy using simulations.

Purpose: To quantitatively evaluate through automated simulations the clinical significance of potential high-dose rate (HDR) prostate brachytherapy (HDRPB) physics errors selected from our internal failure-modes and effect analysis (FMEA).

Methods And Materials: A list of failure modes was compiled and scored independently by 8 brachytherapy physicists on a one-to-ten scale for severity (S), occurrence (O), and detectability (D), with risk priority number (RPN) = SxOxD. Variability of RPNs across observers (standard deviation/average) was calculated.

Impact of use of optical surface imaging on initial patient setup for stereotactic body radiotherapy treatments.

Purpose: To evaluate the effectiveness of surface image guidance (SG) for pre-imaging setup of stereotactic body radiotherapy (SBRT) patients, and to investigate the impact of SG reference surface selection on this process.

Methods And Materials: 284 SBRT fractions (SG-SBRT = 113, non-SG-SBRT = 171) were retrospectively evaluated. Differences between initial (pre-imaging) and treatment couch positions were extracted from the record-and-verify system and compared for the two groups.

Technical Note: The design, construction, and evaluation of a liquid-based single phantom solution for TG128 brachytherapy ultrasound QA.

Purpose: Since the publication of the AAPM TG128 report for the quality assurance (QA) of prostate brachytherapy ultrasound systems, no commercially available phantoms have been developed which satisfy all of the task group recommendations. Current solid phantoms require a separate user-implemented setup using a container with liquid medium to evaluate the alignment between the needle template and the electronic grid, a test of geometric accuracy with critical implications in dosimetric quality. Utilizing a 3D printer, we constructed a cost-effective, liquid-based phantom that provides a complete TG128 solution which improves the efficiency of brachytherapy ultrasound QA.