Stereotactic Body Radiation Therapy for Prostate Cancer Using Tomotherapy With Synchrony Fiducial Tracking

Abstract

Numerous prospective and retrospective studies have demonstrated the efficacy and safety of stereotactic body radiation therapy (SBRT) for prostate cancer. Since SBRT utilizes a very tight margin, management of intrafraction prostate motion is necessary. As a real-time motion tracking and correction system (Synchrony; Accuray, Sunnyvale, CA) has been introduced in the newer platform of tomotherapy (Radixact; Accuray), Radixact can deliver tracking SBRT. In the case report, we present the first clinical experience with prostate SBRT using tomotherapy with Synchrony fiducial tracking.

Simulating an intra-fraction adaptive workflow to enable PTV margin reduction in MRIgART volumetric modulated arc therapy for prostate SBRT

“…One method which will better spare OAR’s and potentially reduce treatment related side effects is the reduction of PTV margins ( 19 ). Reducing PTV margins poses challenges as the prostate exhibits both inter and intra-fraction motion caused by bladder and rectal filling, bowel movement, and skeletal muscular motion ( 20 – 22 ). Therefore, caution should be employed when implementing margin reductions because advanced imaging technologies and strategies may be required to prevent underdosage of the target ( 23 , 24 ).…”

“…Prostate PTV margins ranging from 2 mm to greater than 10 mm have been reported in the literature and this variation often coincides with the type of pretreatment imaging used and whether intra-fraction adaptions are applied (25). Most commonly, PTV margins fall within the range of 4 to 6 mm (22,(26)(27)(28). Keizer et al found that PTV margin reduction below 4 mm would require intra-fraction monitoring and correction (29).…”