Efficacy and Safety of Simultaneous Integrated Boost Radiotherapy in HR/VHR Prostate Cancer With EPLNI

Patients with histopathologically confirmed prostatic adenocarcinoma staged as high-risk / very high-risk localized disease will receive radiotherapy using Simultaneous Integrated Boost Volumetric Modulated Arc Therapy (SIB-VMAT) over a total duration of 4 weeks (20 consecutive working days). Target volumes: PTV-1 (PTV 44 Gy) Prostate + Pelvic Lymph Node PTV (PLNI): 44 Gy delivered in 20 fractions (2.2 Gy/fraction), including the internal iliac, external iliac, obturator, presacral nodal stations, whole prostate, and SV. PTV-2 (PTV 60 GY): 60 Gy delivered in 20 fractions (3 Gy/fraction), including the whole prostate and the base of the SV (proximal 1 cm). Systemic Therapy is allowed during the study when indicated. Patients will receive long-term Androgen Deprivation Therapy (ADT) for a duration of 18-24 months. ADT will be initiated as neoadjuvant therapy 2-3 months prior to the commencement of radiotherapy.