PRO-BOOST-LC: Whole-Gland Boost Strategies Versus SBRT Monotherapy in PSMA-Staged Localized and Locally Advanced Prostate Cancer

NCT07426055 | Recruiting Phase 2 DMC

• 1 other identifier: PRO-BOOST-LC
• Study Type: interventional
• Target: 1,000
• Locations: 1 country
• Sites: 1

Brief Summary

PRO-BOOST-LC is a prospective, multicenter, randomized phase II/III clinical trial for men with localized or locally advanced prostate cancer without lymph node or distant metastases, confirmed using prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT). Radiotherapy is an established curative treatment option for prostate cancer. Several modern radiotherapy strategies can safely deliver high radiation doses to the prostate while limiting dose to surrounding organs. These include stereotactic body radiotherapy (SBRT), high-dose-rate (HDR) brachytherapy, low-dose-rate (LDR) brachytherapy, and combinations of external beam radiotherapy with a prostate boost. However, the optimal dose-escalation strategy for balancing cancer control, treatment-related toxicity, and long-term quality of life remains uncertain in patients staged with modern PSMA PET imaging. The aim of PRO-BOOST-LC is to compare definitive SBRT monotherapy with whole-gland prostate boost strategies delivered after a short course of external beam radiotherapy. Participants will be randomly assigned, according to center capability and patient-level technical suitability, to one of the protocol-defined treatment options. The control group receives SBRT monotherapy. The experimental groups receive external beam radiotherapy followed by one of three whole-gland boost techniques: HDR brachytherapy, LDR brachytherapy, or single-fraction SBRT boost. The primary objective is to determine whether assignment to a prostate boost strategy improves failure-free survival compared with SBRT monotherapy. Failure-free survival includes biochemical recurrence, local or regional progression, distant metastases, progression-driven salvage treatment, or death from any cause. Key secondary outcomes include metastasis-free survival, overall survival, physician-reported treatment-related toxicity, and patient-reported quality of life, including urinary, bowel, and sexual function. Participants will undergo baseline clinical evaluation, PSA testing, prostate MRI, PSMA PET/CT, and quality-of-life assessments. After treatment, participants will be followed regularly with clinical assessments, PSA testing, toxicity evaluation, patient questionnaires, and imaging when clinically indicated. The study is designed to provide long-term evidence on how best to use modern radiotherapy dose escalation for patients with PSMA-staged localized or locally advanced prostate cancer.

Conditions

Prostate Cancer (Adenocarcinoma); Prostate Brachytherapy; Stereotactic Body Radiation Therapy (SBRT); Dose Escalation: Solid Tumors; Localized Prostate Cancer

Keywords

Radiotherapy; Stereotactic Body Radiotherapy; SBRT; Brachytherapy; High-Dose-Rate Brachytherapy; Low-Dose-Rate Brachytherapy; Dose Escalation; Ultrahypofractionation; PSMA PET; Prostate-Specific Membrane Antigen; Metastasis-Free Survival; Failure-Free Survival

Outcome Measures

Primary Outcomes (2)

• Failure-Free Survival (FFS)

  Failure-Free Survival (FFS) is defined as the time from randomization to the earliest occurrence of any of the following events: biochemical recurrence according to the Phoenix definition (PSA nadir + 2 ng/mL), confirmed local recurrence within the prostate, regional pelvic nodal progression, distant metastatic disease, initiation of salvage therapy, or death from any cause. Local recurrence is defined by radiologic progression on multiparametric MRI or PSMA PET/CT confirmed on repeat imaging ≥6 months later, or biopsy-proven viable adenocarcinoma in the presence of radiologic progression. Regional nodal progression includes pelvic nodal relapse (obturator, internal iliac, external iliac, presacral nodes). Patients without an event will be censored at the date of last disease assessment.

  From randomization up to 10 years

• Metastasis-Free Survival (MFS) hierarchical

  Metastasis-Free Survival (MFS) is defined as the time from randomization to the occurrence of distant metastatic disease or death from any cause, whichever occurs first. Distant metastases are defined as non-pelvic nodal disease (including common iliac nodes) or visceral or bone metastases detected preferentially by PSMA PET/CT and confirmed according to protocol-defined imaging criteria. MFS is analyzed as a key confirmatory endpoint within a hierarchical testing strategy and will be formally tested only if the primary comparison for Failure-Free Survival is statistically significant. MFS is assessed in accordance with EAU/ASTRO/STRATOS consensus definitions and is recognized as a validated surrogate for overall survival in localized and locally advanced prostate cancer.

  From randomization up to 10 years

Secondary Outcomes (15)

• Intraprostatic Local Control (iLC)

  From randomization up to 10 years

• Regional Pelvic Nodal Control (rNC)

  From randomization up to 10 years

• Acute Genitourinary and Gastrointestinal Toxicity

  From start of radiotherapy to 90 days after completion

• Late Genitourinary and Gastrointestinal Toxicity

  More than 90 days after completion of radiotherapy up to 10 years

• Expanded Prostate Cancer Index Composite-26 (EPIC-26)

  From baseline up to 10 years

Study Arms (4)

SBRT Monotherapy

ACTIVE COMPARATOR

Patients assigned to this arm receive definitive stereotactic body radiotherapy (SBRT) delivered to the prostate as monotherapy, without any additional intraprostatic boost. Treatment is administered using an ultrahypofractionated regimen with highly conformal dose delivery, daily image guidance, and motion management according to protocol-defined standards. Target volumes and organs at risk are contoured following centralized guidelines, and treatment planning adheres to predefined coverage objectives and dose constraints. This arm represents a contemporary, non-invasive definitive radiotherapy strategy for localized prostate cancer and serves as the active comparator for all boost-based dose escalation approaches evaluated in the study. Androgen deprivation therapy may be administered according to protocol-defined risk group and current clinical practice guidelines.

Radiation: Stereotactic Body Radiotherapy (SBRT) Monotherapy; Drug: Androgen Deprivation Therapy (ADT)

EBRT With HDR Brachytherapy Boost

EXPERIMENTAL

Patients assigned to this arm receive a standardized ultrahypofractionated external beam radiotherapy (EBRT) backbone delivered to the prostate using modern image-guided techniques, followed by an intraprostatic boost delivered with high-dose-rate (HDR) brachytherapy. The EBRT component provides uniform baseline irradiation, after which a single-fraction HDR brachytherapy boost is administered using transperineal catheter placement and afterloading according to protocol-defined technical and dosimetric criteria. This approach enables delivery of a very high biologically effective dose to the prostate while maintaining strict organ-at-risk constraints. Target coverage objectives, applicator placement principles, and dose limits are standardized across centers. Androgen deprivation therapy may be administered according to protocol-defined risk group and standard clinical practice.

Radiation: External Beam Radiotherapy (EBRT) Backbone; Radiation: High-Dose-Rate Brachytherapy Boost; Drug: Androgen Deprivation Therapy (ADT)

EBRT With LDR Brachytherapy Boost

EXPERIMENTAL

Patients assigned to this arm receive a standardized ultrahypofractionated external beam radiotherapy (EBRT) backbone delivered to the prostate, followed by an intraprostatic boost using low-dose-rate (LDR) permanent seed brachytherapy. After completion of EBRT, LDR brachytherapy is performed with transperineal implantation of radioactive seeds according to protocol-defined planning, implantation, and post-implant dosimetric criteria. This strategy achieves dose escalation through continuous low-dose-rate irradiation while respecting predefined target coverage goals and organ-at-risk constraints. Implant quality and dosimetry are centrally specified to ensure consistency across participating centers. Androgen deprivation therapy may be administered based on protocol-defined risk group and standard clinical practice.

Radiation: External Beam Radiotherapy (EBRT) Backbone; Radiation: Low-Dose-Rate Brachytherapy Boost; Drug: Androgen Deprivation Therapy (ADT)

EBRT With SBRT Boost

EXPERIMENTAL

Patients assigned to this arm receive a standardized ultrahypofractionated external beam radiotherapy (EBRT) backbone delivered to the prostate, followed by an intraprostatic stereotactic body radiotherapy (SBRT) boost. The EBRT component establishes baseline target coverage, after which a highly conformal SBRT boost is delivered in a single fraction using advanced image guidance and motion management. This arm represents a fully non-invasive dose escalation strategy that avoids brachytherapy while enabling delivery of a high biologically effective intraprostatic dose. Treatment planning and delivery follow protocol-defined target coverage objectives and organ-at-risk constraints to ensure safety and consistency. Androgen deprivation therapy may be administered according to protocol-defined criteria.

Radiation: External Beam Radiotherapy (EBRT) Backbone; Radiation: Stereotactic Body Radiotherapy (SBRT) Boost; Drug: Androgen Deprivation Therapy (ADT)

Interventions

Stereotactic Body Radiotherapy (SBRT) Monotherapy RADIATION

Stereotactic body radiotherapy (SBRT) delivered to the prostate as definitive monotherapy using an ultrahypofractionated schedule. Treatment is planned with highly conformal techniques and daily image guidance according to protocol-defined target coverage objectives and organ-at-risk constraints. This intervention represents a non-invasive definitive radiotherapy strategy without additional intraprostatic boost.

SBRT Monotherapy

External Beam Radiotherapy (EBRT) Backbone RADIATION

Ultrahypofractionated external beam radiotherapy delivered to the prostate using volumetric modulated arc therapy (VMAT) or equivalent intensity-modulated techniques. This intervention serves as a standardized treatment backbone prior to intraprostatic dose escalation and is delivered according to protocol-defined target volumes, margins, and dose constraints.

EBRT With HDR Brachytherapy Boost; EBRT With LDR Brachytherapy Boost; EBRT With SBRT Boost

High-Dose-Rate Brachytherapy Boost RADIATION

Intraprostatic high-dose-rate brachytherapy delivered as a single-fraction boost following completion of external beam radiotherapy. The procedure involves transperineal catheter placement with afterloading and is performed according to protocol-defined technical, dosimetric, and safety criteria to achieve focal dose escalation while respecting organ-at-risk constraints.

EBRT With HDR Brachytherapy Boost

Low-Dose-Rate Brachytherapy Boost RADIATION

Intraprostatic low-dose-rate permanent seed brachytherapy delivered as a boost following completion of external beam radiotherapy. Radioactive seeds are implanted transperineally according to protocol-defined planning and implantation guidelines to provide continuous low-dose-rate irradiation while maintaining predefined target coverage and organ-at-risk constraints.

EBRT With LDR Brachytherapy Boost

Stereotactic Body Radiotherapy (SBRT) Boost RADIATION

Intraprostatic stereotactic body radiotherapy delivered as a single-fraction boost following completion of external beam radiotherapy. This intervention provides non-invasive dose escalation using highly conformal planning and image guidance according to protocol-defined coverage objectives and organ-at-risk constraints.

EBRT With SBRT Boost

Androgen Deprivation Therapy (ADT) DRUG

Androgen deprivation therapy (ADT) administered according to protocol-defined risk group and standard clinical practice. ADT may include luteinizing hormone-releasing hormone (LHRH) agonists or antagonists, with or without short-course antiandrogens, delivered as neoadjuvant, concurrent, and/or adjuvant therapy in accordance with contemporary clinical guidelines. ADT is not randomized and is applied uniformly within each risk group across all treatment arms.

EBRT With HDR Brachytherapy Boost; EBRT With LDR Brachytherapy Boost; EBRT With SBRT Boost; SBRT Monotherapy

Eligibility Criteria

• Age: 18 Years+
• Gender Eligibility Details: Eligibility is limited by biological sex (presence of prostate).
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male patients aged ≥18 years.
• Histologically confirmed adenocarcinoma of the prostate.
• Localized or locally advanced prostate cancer classified as cT1-4, cN0, cM0.
• Negative pelvic nodal and distant metastatic disease on baseline PSMA PET.
• NCCN favourbale or unfavourbale intermediate-, high-, or very high-risk disease.
• Candidate for definitive radiotherapy with curative intent.
• ECOG performance status 0-2.
• Baseline PSA available prior to randomization.
• Ability to undergo external beam radiotherapy and brachytherapy or SBRT according to protocol.
• Planned androgen deprivation therapy (ADT) permitted according to protocol-defined risk group.
• Ability to understand and willingness to sign written informed consent.

You may not qualify if:

• Evidence of pelvic nodal (cN1) or distant metastatic disease (cM1) on baseline imaging.
• Prior definitive local treatment for prostate cancer, including prostatectomy, brachytherapy, or definitive external beam radiotherapy.
• Prior pelvic radiotherapy for any malignancy.
• Prior systemic therapy for prostate cancer other than protocol-allowed neoadjuvant ADT.
• History of other active malignancy requiring systemic treatment (except adequately treated non-melanoma skin cancer).
• Contraindications to radiotherapy or anesthesia required for brachytherapy procedures.
• Severe uncontrolled comorbidities that would preclude protocol treatment.
• Inability to comply with study procedures or follow-up schedule.

Sponsors & Collaborators

• Affidea Nu-med Center of Oncological DIagnostics and Therapy: lead

Study Sites (1)

Affidea Nu-Med, Center of Oncological Diagnostics and Therapy

Zamość, Lublin Voivodeship, 22-400, Poland

RECRUITING

Related Publications (17)

• National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Prostate Cancer. Version current at study initiation. Available at: https://www.nccn.org/professionals/physician_gls/pdf/prostate.pdf

  BACKGROUND

• Sidibe I, Beaudry MM, Carignan D, Froment MA, Foster W, Bachand F, Vigneault E, Magnan S, Aubin S, Morrier J, Poulin E, Lacroix F, Lavallee MC, Beaulieu L, Martin AG. Ultra-hypofractionated radiotherapy combined with HDR brachytherapy: An optimized treatment. Radiother Oncol. 2026 Jan;214:111199. doi: 10.1016/j.radonc.2025.111199. Epub 2025 Oct 9.

  PMID: 41067642 BACKGROUND

• Mendez LC, Crook J, Martell K, Schaly B, Hoover DA, Dhar A, Velker V, Ahmad B, Lock M, Halperin R, Warner A, Bauman GS, D'Souza DP. Is Ultrahypofractionated Whole Pelvis Radiation Therapy (WPRT) as Well Tolerated as Conventionally Fractionated WPRT in Patients With Prostate Cancer? Early Results From the HOPE Trial. Int J Radiat Oncol Biol Phys. 2024 Jul 1;119(3):803-812. doi: 10.1016/j.ijrobp.2023.11.058. Epub 2023 Dec 8.

  PMID: 38072323 BACKGROUND

• Beaudry MM, Carignan D, Foster W, Lavallee MC, Aubin S, Lacroix F, Poulin E, Lachance B, Despres P, Beaulieu L, Vigneault E, Martin AG. Comparison of four-year toxicities and local control of ultra-hypofractionated vs moderate-hypofractionated image guided prostate radiation with HDR brachytherapy boost: A phase I-II single institution trial. Clin Transl Radiat Oncol. 2023 Feb 8;40:100593. doi: 10.1016/j.ctro.2023.100593. eCollection 2023 May.

  PMID: 36875870 BACKGROUND

• Gorovets D, Hopkins M, Kollmeier M, Moore A, Goel A, Shasha D, Brennan V, McBride S, Cohen G, Damato AL, Zelefsky MJ. Early outcomes of high-dose-rate brachytherapy combined with ultra-hypofractionated radiation in higher-risk prostate cancer. Brachytherapy. 2021 Nov-Dec;20(6):1099-1106. doi: 10.1016/j.brachy.2021.08.006. Epub 2021 Sep 26.

  PMID: 34588146 BACKGROUND

• Kollmeier MA, Gorovets D, Flynn J, McBride S, Brennan V, Beaudry J, Cohen G, Damato A, Zhang Z, Zelefsky MJ. Combined brachytherapy and ultra-hypofractionated radiotherapy for intermediate-risk prostate cancer: Comparison of toxicity outcomes using a high-dose-rate (HDR) versus low-dose-rate (LDR) brachytherapy boost. Brachytherapy. 2022 Sep-Oct;21(5):599-604. doi: 10.1016/j.brachy.2022.04.006. Epub 2022 Jun 17.

  PMID: 35725549 BACKGROUND

• Martin J, Keall P, Siva S, Greer P, Christie D, Moore K, Dowling J, Pryor D, Chong P, McLeod N, Raman A, Lynam J, Smart J, Oldmeadow C, Tang CI, Murphy DG, Millar J, Tai KH, Holloway L, Reeves P, Hayden A, Lim T, Holt T, Sidhom M. TROG 18.01 phase III randomised clinical trial of the Novel Integration of New prostate radiation schedules with adJuvant Androgen deprivation: NINJA study protocol. BMJ Open. 2019 Aug 20;9(8):e030731. doi: 10.1136/bmjopen-2019-030731.

  PMID: 31434782 BACKGROUND

• Wang SC, Ting WC, Chang YC, Yang CC, Lin LC, Ho HW, Chu SS, Lin YW. Whole Pelvic Radiotherapy With Stereotactic Body Radiotherapy Boost vs. Conventionally Fractionated Radiotherapy for Patients With High or Very High-Risk Prostate Cancer. Front Oncol. 2020 May 29;10:814. doi: 10.3389/fonc.2020.00814. eCollection 2020.

  PMID: 32547949 BACKGROUND

• Lischalk JW, Akerman M, Repka MC, Sanchez A, Mendez C, Santos VF, Carpenter T, Wise D, Corcoran A, Lepor H, Katz A, Haas JA. High-risk prostate cancer treated with a stereotactic body radiation therapy boost following pelvic nodal irradiation. Front Oncol. 2024 Feb 6;14:1325200. doi: 10.3389/fonc.2024.1325200. eCollection 2024.

  PMID: 38410097 BACKGROUND

• Wegener E, Sidhom M, Pryor D, Bucci J, Yeoh K, Richardson M, Greer P, Wilton L, Gallagher S, Schmidt L, Arumugam S, Keats S, Brown S, Glyde A, Martin JM. Prostate Virtual High-dose-rate Brachytherapy Boost: 5-Year Results from the PROMETHEUS Prospective Multicentre Trial. Eur Urol Oncol. 2024 Oct;7(5):1042-1050. doi: 10.1016/j.euo.2024.01.008. Epub 2024 Feb 1.

  PMID: 38302321 BACKGROUND

• Bilski M, Lelek P, Stankiewicz M, Miszczyk M, Burchardt W, Kluska A, Napieralska A, Kukielka A, Cisek P, Konat-Baska K, Stando R, Dec M, Piliszczuk E, Matys R, Bajon T, Trojanowski M, Moll M, Gomez-Iturriaga A, Chichel A, Wojcieszek P, Shariat SF, Chyrek AJ. MUlticentre REtrospective comparison of definitive EBRT with or without HDR BRAchytherapy boost in patients with locally-advanced prostate cancer and regional lymph NOde metastases (MUREBRANO) - A propensity score matched analysis. Radiother Oncol. 2025 Nov;212:111112. doi: 10.1016/j.radonc.2025.111112. Epub 2025 Aug 27.

  PMID: 40882818 BACKGROUND

• Miszczyk M, Magrowski L, Krzysztofiak T, Stando R, Majewski W, Stawiski K, Masri O, Ciepal J, Depowska G, Chimiak K, Bylica G, Czapla B, Masri M, Cichur F, Jablonska I, Gmerek M, Nowicka Z, Wojcieszek P, Sadowski J, Suwinski R, Rajwa P, Goldner G, Moll M. Brachytherapy boost improves survival and decreases risk of developing distant metastases compared to external beam radiotherapy alone in intermediate and high risk group prostate cancer patients. Radiother Oncol. 2023 Jun;183:109632. doi: 10.1016/j.radonc.2023.109632. Epub 2023 Mar 23.

  PMID: 36963442 BACKGROUND

• Strouthos I, Karagiannis E, Antorkas G, Roussakis Y, Cloconi C, Savva A, Christoforou A, Vrachimis A, Zamboglou C, Ferentinos K. Combined Hypofractionated Radiation Therapy and Brachytherapy for Managing Prostate-Specific Membrane Antigen Positron Emission Tomography-Staged Organ-Confined Prostate Cancer: Primary Endpoint Analysis of a Prospective Study. Pract Radiat Oncol. 2025 Nov-Dec;15(6):e606-e616. doi: 10.1016/j.prro.2025.03.013. Epub 2025 Jun 20.

  PMID: 40539958 BACKGROUND

• Hoskin PJ, Rojas AM, Ostler PJ, Bryant L, Lowe GJ. Randomised trial of external-beam radiotherapy alone or with high-dose-rate brachytherapy for prostate cancer: Mature 12-year results. Radiother Oncol. 2021 Jan;154:214-219. doi: 10.1016/j.radonc.2020.09.047. Epub 2020 Oct 2.

  PMID: 33011207 BACKGROUND

• Rodda S, Tyldesley S, Morris WJ, Keyes M, Halperin R, Pai H, McKenzie M, Duncan G, Morton G, Hamm J, Murray N. ASCENDE-RT: An Analysis of Treatment-Related Morbidity for a Randomized Trial Comparing a Low-Dose-Rate Brachytherapy Boost with a Dose-Escalated External Beam Boost for High- and Intermediate-Risk Prostate Cancer. Int J Radiat Oncol Biol Phys. 2017 Jun 1;98(2):286-295. doi: 10.1016/j.ijrobp.2017.01.008. Epub 2017 Jan 6.

  PMID: 28433432 BACKGROUND

• Oh J, Tyldesley S, Pai H, McKenzie M, Halperin R, Duncan G, Morton G, Keyes M, Hamm J, Morris WJ. An Updated Analysis of the Survival Endpoints of ASCENDE-RT. Int J Radiat Oncol Biol Phys. 2023 Apr 1;115(5):1061-1070. doi: 10.1016/j.ijrobp.2022.11.005. Epub 2022 Dec 15.

  PMID: 36528488 BACKGROUND

• Morris WJ, Tyldesley S, Rodda S, Halperin R, Pai H, McKenzie M, Duncan G, Morton G, Hamm J, Murray N. Androgen Suppression Combined with Elective Nodal and Dose Escalated Radiation Therapy (the ASCENDE-RT Trial): An Analysis of Survival Endpoints for a Randomized Trial Comparing a Low-Dose-Rate Brachytherapy Boost to a Dose-Escalated External Beam Boost for High- and Intermediate-risk Prostate Cancer. Int J Radiat Oncol Biol Phys. 2017 Jun 1;98(2):275-285. doi: 10.1016/j.ijrobp.2016.11.026. Epub 2016 Nov 24.

  PMID: 28262473 BACKGROUND

Related Links

• NCCN Clinical Practice Guidelines in Oncology for Prostate Cancer, providing contemporary standards for risk stratification, imaging including PSMA PET, and multimodality radiotherapy strategies relevant to the PRO-BOOST-LC trial.
• European Association of Urology (EAU) Guidelines on Prostate Cancer, including recommendations on PSMA PET staging, definitions of metastasis-free survival, and contemporary management of localized and locally advanced disease.
• ClinicalTrials.gov registry providing public information on interventional clinical studies, including protocol structure, predefined endpoints, and transparency standards applied in the PRO-BOOST-LC trial.

MeSH Terms

Conditions

Prostatic Neoplasms; Adenocarcinoma

Interventions

Radiosurgery; Androgen Antagonists

Condition Hierarchy (Ancestors)

Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Genital Diseases; Urogenital Diseases; Prostatic Diseases; Male Urogenital Diseases; Carcinoma; Neoplasms, Glandular and Epithelial; Neoplasms by Histologic Type

Intervention Hierarchy (Ancestors)

Radiotherapy; Therapeutics; Stereotaxic Techniques; Neurosurgical Procedures; Surgical Procedures, Operative; Investigative Techniques; Hormone Antagonists; Hormones, Hormone Substitutes, and Hormone Antagonists; Physiological Effects of Drugs; Pharmacologic Actions; Chemical Actions and Uses

Study Officials

• Mateusz Bilski, MD PhD

  Affidea Nu-Med, Center of Oncological Diagnostics and Therapy, Zamość, Poland

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Mateusz Edward Bilski, MD, PhD

CONTACT

048 84 535 99 10; bilskimat@gmail.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Medical Director and Head of Radiotherapy Department, MD, PhD

Model Details: This is a multicenter, prospective, randomized, open-label, parallel-group phase II/III radiotherapy trial evaluating definitive prostate dose-escalation strategies for patients with localized or locally advanced prostate cancer staged as cN0/cM0 by PSMA PET/CT. Participants are randomized within a capability-based allocation framework. The patient-level randomization set is defined before allocation according to center credentialing and technical suitability for the individual patient. The protocol includes four treatment strategies: SBRT monotherapy, EBRT followed by HDR brachytherapy boost, EBRT followed by LDR brachytherapy boost, and EBRT followed by single-fraction SBRT boost. The primary comparison is pooled whole-gland boost strategies versus SBRT monotherapy. Outcomes are compared between parallel groups for disease control, toxicity, and patient-reported quality of life.

Study Record Dates

• First Submitted: February 7, 2026
• First Posted: February 23, 2026
• Study Start: March 19, 2026
• Primary Completion (Estimated): December 1, 2033
• Study Completion (Estimated): December 1, 2035
• Last Updated: July 21, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: IPD and supporting documentation will become available beginning 6 months after publication of the primary results and will remain available for a minimum of 5 years following publication.
• Access Criteria: Access to de-identified IPD will be granted to qualified researchers who submit a written request describing the research question, analysis plan, and intended use of the data. Requests will be reviewed by the study steering committee to ensure scientific merit, feasibility, and compliance with ethical and data protection requirements. Approved users will be required to sign a data use agreement prior to data release.

Locations

PL (1)