The PART randomised trial protocol: Partial Ablation versus Radical Treatment for prostate cancer

Primary objective: to determine whether prostate gland partial ablation (PA) has non-inferior oncological treatment success vs radical treatment (RT) of localised intermediate-risk prostate cancer (irPCa).

to compare (i) participant-reported urinary and sexual dysfunction side effects, (ii) short/medium term serious adverse events, (iii) health-related quality of life (HRQoL), (iv) cost-effectiveness; and to report (v) the need for repeat PA, (vi) accuracy of magnetic resonance imaging and biopsy protocols in determining suitability for PA, (vii) disease progression, local spread and metastases, (viii) medium-term disease-specific and overall mortality.

The 'Partial prostate Ablation versus Radical Treatment' (PART; International Standard Randomised Controlled Trial Number ISRCTN17249875) is a UK-wide, multicentre, pragmatic, randomised controlled trial investigating whether PA (high-intensity focused ultrasound [HIFU] or irreversible electroporation [IRE]) is non-inferior to RT (radical prostatectomy, radical radiotherapy, or low-dose-rate brachytherapy [LDR-B]) in treating localised irPCa. A Qualitative Research Integrated within Trials (QuinteT) Recruitment Intervention is included to optimise recruitment and informed consent. Primary outcome treatment success for PA will be determined by prostate biopsies and imaging, and for RT using standard definitions. Participants will receive treatment according to their randomised allocation, with HIFU or IRE for PA depending on lesion location, and radical prostatectomy, radical radiotherapy, or LDR-B according to patient and physician preference for RT. Based on 95% and 85% oncological treatment success for RT and PA, respectively, with a non-inferiority margin of 20%, at median 3 years of follow-up, PART requires 275 recruited men (137 per group, randomised on a 1:1 basis), for 80% power, with a one-sided alpha of 0.025. Allowing for a 10% total withdrawal or dropout rate, PART requires 306 recruited and randomised participants.

The PART trial will provide robust prospective data and high-level randomised evidence to determine oncological treatment effectiveness of PA vs RT for localised irPCa, along with comparative side effect, HRQoL, and health economics evaluations, to inform clinical decision-making.