Potency pReservation In Prostate cAncer Patients Treated With UltraSound-guided Low-dose Rate Brachytherapy (PRIAPUS)
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|ClinicalTrials.gov Identifier: NCT04718987|
Recruitment Status : Recruiting
First Posted : January 22, 2021
Last Update Posted : May 17, 2022
|Condition or disease||Intervention/treatment||Phase|
|Prostate Cancer||Radiation: Low dose rate (LDR) brachytherapy||Not Applicable|
Low dose rate (LDR) brachytherapy is an excellent treatment strategy for patients with prostate confined cancers, achieving high curative rates. However, LDR brachytherapy has been linked with long-term erectile dysfunction (ED), with a broad range of reported incidence in the literature.
The pathophysiology associated with ED is complex and variable among different prostate cancer treatment strategies. In the post radical prostatectomy (RP) setting, ED is usually an immediate phenomenon and associated with neuropraxia caused by trauma and inflammation (Nandipati 2006). On the contrary, external beam radiotherapy (EBRT) related ED frequently occurs between 6-24 months and is believed to be vasculogenic in nature and caused by veno-vascular luminal occlusion (Mulhall et al. 2005) that culminates into fibrosis of the corporal tissue. In the post brachytherapy setting, seems plausible that a combination of both nerve and vascular damage are involved in the ED pathogenesis as erectile scores seem to reduce in the first months post implant (likely due to trauma) followed by a subsequent recovery and then, a gradual decline (Mabjeesh 2005).
Despite a more complex pathophysiology, rates of ED post LDR brachytherapy seem to be lower than post EBRT or RP treatment (Crook 2010, Putora 2015). This may be associated with a significantly lower degree of trauma to the surrounding healthy tissue compared with trauma caused by RP and a more conformal dose around the prostate when contrasted with EBRT. In this regard, brachytherapy delivers a lesser dose to important structures previously correlated with an erectile function such as the internal pudendal artery (IPA), penile bulb, corpus cavernosum and possibly the neurovascular bundle.
Currently, some strategies have been developed in an attempt to minimize ED post radiotherapy. In the POTEN-C clinical trial (NCT03525262), 120 patients are being randomized to stereotactic ablative radiotherapy with or without neurovascular sparing (neurovascular bundle, IPA and penile bulb/corpus carvenosum) with ED as the primary endpoint. Although the concept is intriguing, LDR brachytherapy has superior dose conformality and hence, a better chance to reduce radiation dose to the surrounding structures involved in the erectile function while still effectively treating the prostate cancer.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||10 participants|
|Intervention Model:||Single Group Assignment|
|Intervention Model Description:||Prospective, single-arm clinical trial to enroll a total of 10 low- or favourable intermediate-risk prostate cancer patients.|
|Masking:||None (Open Label)|
|Official Title:||Potency pReservation In Prostate cAncer Patients Treated With UltraSound-guided Low-dose Rate Brachytherapy|
|Actual Study Start Date :||June 1, 2021|
|Estimated Primary Completion Date :||December 2022|
|Estimated Study Completion Date :||December 2025|
Experimental: Prostate Cancer Patients
Low- or favourable intermediate-risk prostate cancer patients
Radiation: Low dose rate (LDR) brachytherapy
Low dose rate (LDR) brachytherapy is a type of radiation treatment where doctor places the radioactive implants (seeds) inside patient's prostate gland and these seeds emits low dose radiation over a certain period of time. During low-dose-rate brachytherapy, a continuous low dose of radiation is released over time -from several hours to several days.
- Rate of patients receiving this experimental brachytherapy technique and achieving acceptable dose distribution at 1-month post-implant. [ Time Frame: 1 month after intervention ]
Acceptable dose distribution is defined as:
- Target volume (Prostate, excluding a 5 mm expansion of the Neurovascular bundle) D90 ≥ 140 Gy
- Contralateral neurovascular bundle median dose ≤ 50 Gy
- Prostatic bulb D10 dose ≤ 50 Gy (Chasseray 2019)
- Urethra D30 < 130% of the prescription dose
- Number of patient with preserved erectile function Erectile Function (IIEF) >= 18) [ Time Frame: 1, 6, 12, 18, 24, 36, 48, 60 months post intervention ]
The IIEF classifies the severity of ED into five categories stratified by score
- No ED.26-30
- Mild to moderate.17-21
- Post-procedure PSA dynamic [ Time Frame: 6, 12, 18, 24, 36, 48, 60 months post intervention ]PSA curve post procedure
- Acute and long-term GU and GI toxicity [ Time Frame: 1, 6, 12, 18, 24, 36, 48, 60 months post intervention ]Evaluate acute and long-term G3 or larger toxicity based on NCI-CTCAE 5.0 score system. Grade 1 to Grade 5. Higher the grade more severe is the toxicity.
- Biochemical failure [ Time Frame: 1, 6, 12, 18, 24, 36, 48, 60 months post intervention ]Biochemical failure will be assessed according to the Phoenix criteria (nadir + 2.0ng/mL)
- Local recurrence [ Time Frame: Until study completion with 5 years of follow up ]To assess the rate of biopsy-proven local recurrence
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04718987
|Contact: Robin Sachdeva, PhD||519-685-8500 ext firstname.lastname@example.org|
|London Regional Cancer Program||Recruiting|
|London, Ontario, Canada, N6A 5W9|
|Contact: Robin Sachdeva, PhD 519-685-8500 ext 54005 email@example.com|
|Principal Investigator: Lucas Mendez, MD, PhD|
|Principal Investigator:||Lucas Mendez, MD||London Health Sciences Centre- London Regional Cancer Program|