Stereotactic radiotherapy with focal boost for intermediate and high-risk prostate cancer: Initial results of the SPARC trial.
Loading...
Embargo End Date
ICR Authors
Authors
Nicholls, L
Suh, Y-E
Chapman, E
Henderson, D
Jones, C
Morrison, K
Sohaib, A
Taylor, H
Tree, A
van As, N
Suh, Y-E
Chapman, E
Henderson, D
Jones, C
Morrison, K
Sohaib, A
Taylor, H
Tree, A
van As, N
Document Type
Journal Article
Date
2020-11-01
Date Accepted
2020-10-14
Abstract
INTRODUCTION: Dose escalation to dominant intraprostatic lesions (DILs) is a novel method to increase the therapeutic ratio in localised prostate cancer. The Stereotactic Prostate Augmented Radiotherapy with Cyberknife (SPARC) trial was designed to determine the feasibility of a focal boost defined with multiparametric magnetic resonance imaging (mpMRI) using stereotactic ablative body radiotherapy (SABR). MATERIALS AND METHODS: Patients were included with newly diagnosed intermediate to high risk prostate cancer with at least one of: Gleason score 4 + 3, stage T3a, or PSA > 20 ng/ml. Visible disease on mpMRI was mandatory and up to 2 separate nodules were allowed. All patients received androgen deprivation. Patients received 36.25 Gy in 5 fractions using CyberKnife® and the DIL received a simultaneous boost to a maximum of 47.5 Gy, as allowed by OAR constraints. Genitourinary (GU) and gastrointestinal (GI) toxicity was reported using the RTOG scoring criteria. International Index of Erectile Function (IIEF) and EQ-5D global health scores were regularly captured. RESULTS: An interim safety analysis was performed on the first 8 patients, recruited between July 2013 and December 2015. Median follow up was 56 months (range 50-74). Median D95 values for the prostate PTV and boost volume were 36.55 Gy (range 35.87-36.99) and 46.62 Gy (range 44.85-48.25) respectively. Of the dose constraints, 10/80 were not achieved but all were minor dose variations. Grade 2+ acute GU and GI toxicities were 37.5% respectively while grade 2+ late GU and GI toxicities were 12.5% and 0% respectively. IIEF and quality of life scores recovered over time and all patients remain in biochemical remission. CONCLUSION: The first patients have been successfully treated with prostate SABR and focal boost on the SPARC trial, with excellent adherence to the planning protocol. Toxicity and efficacy results are promising and further recruitment is underway.
Citation
Clinical and translational radiation oncology, 2020, 25 pp. 88 - 93
Source Title
Publisher
ELSEVIER IRELAND LTD
ISSN
2405-6308
eISSN
2405-6308
Collections
Research Team
Stereotactic and Precision Body Radiotherapy
Stereotactic and Precision Body Radiotherapy
Stereotactic and Precision Body Radiotherapy