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

Inclusion Criteria: * 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. Exclusion Criteria: * 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.