Clinical Trial Details
— Status: Recruiting
Administrative data
NCT number |
NCT05668351 |
Other study ID # |
103629 |
Secondary ID |
|
Status |
Recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
May 12, 2023 |
Est. completion date |
January 15, 2026 |
Study information
Verified date |
October 2023 |
Source |
Medical University of South Carolina |
Contact |
Alan Brisendine |
Phone |
843-792-6382 |
Email |
brisend[@]musc.edu |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
This single arm trial will investigate a novel way to plan and deliver SABR for prostate
cancer. Prostate-directed SABR will be high-dose SABR (40 Gy in 5 fractions) with central
sparing of the urethra and peripheral sparing of the rectum and pudendal arteries
(SUPR-SABR). This study tests the hypothesis that genitourinary (GU) and gastrointestinal
(GI) toxicity rates following SUPR-SABR are comparable to (or possibly lower than) historical
GU and GI toxicity rates following standard SABR (stSABR) with 36.25 Gy in the treatment of
low- and intermediate-risk prostate cancer.
Description:
It is estimated that there will be 268,000 prostate cancer diagnoses and nearly 35,000 deaths
due to prostate cancer in the United States in 2022 [1]. Most men diagnosed with prostate
cancer present with localized or organ confined disease which is most commonly managed with
active surveillance, prostatectomy, brachytherapy, and external beam radiotherapy (EBRT).
Conventionally fractionated (1.8-2.0 Gy per fraction for nine weeks) EBRT is of historical
and clinical importance in localized prostate cancer, however, moderately hypofractionated
(≥2.5 Gy per fraction for four to six weeks) EBRT and SABR have also emerged as standards of
care in appropriately selected patients.
The increased precision associated with image guided stereotactic techniques now permits safe
delivery of large doses per fraction, also known as hypofractionation. SABR is a specific
type of hypofractionated RT. Hallmarks of the SABR technique, also commonly known as
stereotactic body radiotherapy (SBRT), include doses of at least 5 Gy per fraction, five or
fewer fractions, motion management, noncoplanar beam or arc therapy, body immobilization, and
ablative prescription doses.
There is growing interest in the use of SABR in men with low- and intermediate- risk prostate
cancer due to their lower risk of extra prostatic disease including pelvic lymph node
micrometastases and the low alpha/beta ratio of prostate cancer. Several series with follow
up times exceeding five years have demonstrated excellent biochemical control for SABR
approaching 95% for low risk and 80-90% for intermediate risk disease with low rates of
clinically significant late GU and GI toxicity. Most published clinical experiences of SABR
for prostate cancer have employed 35 to 36.25 Gy in 7- to 7.25 Gy fractions (i.e., standard
SABR or stSABR). Importantly, it has never been established whether this represents the
optimal dose level for SABR and, nationally, there is not only a single standard of care for
SABR prescription dose and fractionation. What is more, contemporary literature with prostate
SABR suggests a benefit with dose escalation, however, there is interest in avoiding a
parallel increase in GU, GI, and sexual side effects of treatment.
The proposed trial concept would offer men with low- and intermediate-risk prostate cancer a
dose-escalated SABR regimen (SUPR-SABR) of 40 Gy in 5 fractions with a safety profile already
supported by medical literature and which is expectedly more efficacious than stSABR. This
dose and fractionation is already being used in some radiation oncology practices. However,
to further improve the therapeutic index of curative RT, the protocol will employ all
available methods to spare the urethra, pudendal artery, and rectum (SUPR-SABR): foley
catheter placement during planning, rectal spacer gel placement, endorectal balloon during
planning and treatment, prostatic immobilization, strict contouring and dose constraints, and
the most highly conformal photon planning available. This protocol will offer men a clinical
study with highly important endpoints and lower anticipated treatment related morbidity. If
the primary analysis demonstrates favorable healthcare related quality of life (HRQOL) with
SUPR-SABR when compared to prospectively collected historic controls of stSABR, then this
would serve as the basis for a randomized trial between SUPR-SABR and stSABR.