Abstract
BackgroundCombination therapy using external-beam radiotherapy (EBRT) with a brachytherapy boost has demonstrated superior biochemical control than dose-escalated EBRT alone. Whereas brachytherapy is disadvantageous because it is an invasive procedure, stereotactic body-radiotherapy (SBRT) using CyberKnife could emulate the dose distribution of brachytherapy and is a non-invasive and safe modality to control intra-fractional movement. We therefore adopted SBRT using CyberKnife as a boost therapy after whole-pelvic radiotherapy (WPRT).Methods/designIn this prospective, randomized, single-center, pilot study for intermediate- and high-risk prostate cancer without nodal or distant metastasis, after androgen-deprivation therapy and WPRT, patients will be randomized to one of two SBRT boost regimens, i.e., 18 or 21 Gy administered in three fractions every other day.DiscussionThe aim of this trial is to evaluate acute toxicities using both physician- and patient-reported outcomes and short-term biochemical control with SBRT boost following WPRT. Additionally, chronic toxicities and long-term biochemical control will be evaluated as secondary endpoints in this trial. Based on the generated results, we will plan the full-scale phase II study for selecting the SBRT boost dose.Trial registrationClinicalTrials.gov, ID; NCT03322020. Retrospectively registered on 26 October 2017.
Highlights
Combination therapy using external-beam radiotherapy (EBRT) with a brachytherapy boost has demonstrated superior biochemical control than dose-escalated EBRT alone
A large comprehensive review involving over 52,000 patients reported that combination therapy including EBRT and brachytherapy appears superior to localized treatment alone in intermediate- and high-risk prostate cancer patients [6]
Spratt et al reported that compared with high-dose Intensity-modulated radiotherapy (IMRT) alone, brachytherapy in combination with IMRT was associated with better 7-year Biochemical recurrencefree survival (BCRFS) rates (81.4% vs 92.0%, P < .001) and better distant metastasis-free survival (93.0 vs 97.2%, P = .04) for patients with intermediate-risk prostate cancer [4]
Summary
A large comprehensive review involving over 52,000 patients reported that combination therapy including EBRT and brachytherapy appears superior to localized treatment alone in intermediate- and high-risk prostate cancer patients [6]. A recent Canadian phase III study demonstrated that patients receiving low-dose-rate brachytherapy boost were twice as likely to be free of BCR compared with those receiving dose-escalated EBRT boost [5]. SBRT itself has the potential to increase the therapeutic ratio as well, given that prostate cancer was reported to have a low α/β ratio with high sensitivity for large fraction sizes [8] This trial uses PRO as well as CTCAE toxicity criteria for accurate assessment of toxicities. We anticipate acceptable acute toxicities and favorable short-term control of PSA in intermediate- and high-risk prostate cancer patients who receive the combination treatment of ADT, WPRT, and SBRT boost.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
