Investigation of maintenance of erectile function after MR-guided radiotherapy with neurovascular sparing in patients with localized prostate cancer.
ID
Source
Brief title
Condition
- Reproductive neoplasms male malignant and unspecified
- Genitourinary tract disorders NEC
- Prostatic disorders (excl infections and inflammations)
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Primary endpoint: the incidence of erectile dysfunction (ED) three years after
treatment.
Secondary outcome
Secondary endpoints: erectile dysfunction (at 6, 12 and 24 months),
relapse-free survival, acute and late urogenital and gastrointestinal toxicity,
and patient-reported quality of life.
Background summary
Erectile dysfunction is a frequent side effect of external radiotherapy (EBRT)
for prostate cancer. To date, anatomy-based treatments developed to conserve
relevant neurovascular structures, such as the pudenda interna and
neurovascular bundles, have not yet been routinely implemented in the clinic.
The implementation of magnetic resonance imaging (MRI) in the planning and
introduction of *Intensity Modulated Radiotherapy* (IMRT) and *Volumetric Arc
Therapy* (VMAT) have improved treatment precision and enabled anatomy-focused
external beam radiation and neurovascular sparing treatments made. Spratt et
al. Conducted a one-arm phase 2 study to investigate the effect of
vascular-sparing IMRT treatments and found significantly improved 2-year
erectile function (78%, 95% confidence interval [CI] 71-85%) compared to
conventional radiotherapy (42%, 95% CI 38-45%; p <0.001) or nerve-sparing
prostatectomy (24%, 95% CI 22-27%; p <0.001). The MRI linear accelerator
(MR-Linac) has recently been introduced in the UMCU. This new system enables
radiation delivery under highly accurate MRI visualization. The MR-Linac is
therefore the most suitable technique for neurovascular-sparing external
radiotherapy treatments. Such neurovascular-sparing treatments can
significantly improve the degree of erectile function after radiotherapy and
thus can improve the quality of life without substantially compromising the
oncological outcome.
Study objective
Investigation of maintenance of erectile function after MR-guided radiotherapy
with neurovascular sparing in patients with localized prostate cancer.
Study design
The *EREctile function preservation for prostate Cancer radiation Therapy
(ERECT)* single-center phase 2 study. Patients are treated with the MR-Linac up
to 5 fractions of 7.25 Gy with neurovascular sparing. All fractions are
delivered in the course of two and a half weeks.
Intervention
All patients will receive MR-Linac treatment consisting of 5 fractions of 7.25
Gy with neurovascular sparing (i.e. additional sparing of the neurovascular
bundles, internal pudendal arteries, penile bulb and corpora carvernosa).
Fractions will be delivered with an overall treatment time of two and a half
weeks.
Study burden and risks
Nature and magnitude of the burden and risks associated with participation,
benefit and group-relatedness: Participants will receive neurovascular sparing
MR-guided radiation therapy (MRgRT) consisting of 5 fractions of 7.25 Gy. The
number of fractions and the duration of treatment is comparable to conventional
MRgRT, consisting of 5 fractions of 7.25 Gy. No increase in toxicity is
expected because the dose limitations for the organs at risk in the
neurovascular sparing radiation plan will be identical to a conventional
radiation plan (i.e. bladder, rectum, femoral head and anal sphincter). For
neurovascular sparing treatment, the protocol is extended to include dose
restrictions for newly identified risk organs (ie neurovascular bundles (NVB),
arteria pudenda interna (IPA), corpora cavernosa (CC) and bulbus penis (PB)).
Sparing these structures can reduce erectile dysfunction after treatment. The
dose to the dorsolateral part of the prostate may be lower in the neurovascular
radiation plan, since the NVB is close to this part of the prostate. A light
dose concession on the dorsolateral part of the prostate is only allowed if the
visible tumor on multiparametric MRI is not in the vicinity of the NVB, since
underdosing of the dominant index lesion is undesirable for tumor control. A
lower dose to the dorsolateral part of the prostate may affect biochemical
control in some cases, but we do not expect this to affect overall survival
Heidelberglaan 100
Utrecht 3584 CX
NL
Heidelberglaan 100
Utrecht 3584 CX
NL
Listed location countries
Age
Inclusion criteria
• Age >= 18 years
• Histologically proven adenocarcinoma of the prostate
• Low-risk or intermediate-risk prostate cancer according to NCCN risk
categories (low risk: T1c-T2a, Gleason score <=6, and PSA <10 µg/L; intermediate
risk: T2b-T2c or Gleason score 7 or PSA 10-20 µg/L)
• Patients with pT1a/b tumor diagnosis after transurethral resection of the
prostate (TURP)
• Domain score of 17-25 on the International Index of Erectile Function-5
(IIEF-5) questionnaire
• Karnofsky score of 70-100
• Written informed consent
Exclusion criteria
Use of (neo-)adjuvant androgen deprivation therapy
• High-risk prostate cancer according to NCCN risk categories (T3a or Gleason
score 8-10 or PSA >20 µg/L)
• Patients with *bulky* iT3 tumor diagnosis
• Previous pelvic irradiation or radical prostatectomy
• Clinical evidence of metastatic disease
• Patients who meet exclusion criteria for MRI following the protocol of the
radiology department of the UMC Utrecht (see appendix I)
• Patients who are incompetent to sign written informed consent
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL73192.041.20 |